High Flow Nasal Cannula Therapy in Acute Bronchiolitis: an Italian Children’s Hospital Protocol

High Flow Nasal Cannula Therapy in Acute Bronchiolitis: an Italian Children’s Hospital Protocol | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article High Flow Nasal Cannula Therapy in Acute Bronchiolitis: an Italian Children’s Hospital Protocol Cristina Giugni, Costanza Cecchi, Laura Nanni, Zaccaria Ricci This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9159619/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 7 You are reading this latest preprint version Abstract Background: Bronchiolitis is the leading cause of non-elective hospitalizations in infants, with an increasing use of High-Flow Nasal Cannula (HFNC) therapy outside the Pediatric Intensive Care Unit (PICU). At our hospital, HFNC was used to treat pediatric bronchiolitis patients without a standardized protocol for initiation, flow titration, escalation, or a PICU alert system in cases of clinical deterioration. Objective and Study Design: This quality improvement project aimed to evaluate the feasibility of a multidisciplinary protocol designed to standardize HFNC use for bronchiolitis in patients under 24 months of age, admitted to the Emergency Department (ED) during the 2021-2023 winter seasons and through the first 72 hours of hospitalization. The primary outcomes were healthcare provider adherence and staff satisfaction. The protocol utilized the Clinical Respiratory Score (CRS) to guide therapy: low-flow oxygen for CRS 7. Satisfaction was assessed via a questionnaire stratified by clinical experience. As a secondary objective, CRS and clinical outcomes (length of stay [LOS] and PICU admission rates) of the per-protocol group were compared to a historical cohort admitted to our hospital during the two preceding winter seasons. Results: Prospective data from 114 patients were analyzed; 97 were managed in full compliance with the protocol, yielding an adherence rate of 85.1%. Staff satisfaction was 100% among pediatric residents (n=5) and junior physicians (<5 years of experience, n=15), while senior physicians (≥5 years of experience, n=15) reported a 70% satisfaction rate. No significant differences were observed in LOS (6.13 ± 2.60 days per-protocol vs. 7.12 ± 8.95 days pre-protocol; p=0.303) or PICU admission rates (20.6% per-protocol vs. 11.6% pre-protocol; p=0.150). In the retrospective cohort (n=86), the mean CRS at ED admission was significantly lower than in the per-protocol group (p < 0.001). However, the per-protocol group exhibited significantly lower CRS values at 48 and 72 hours (p < 0.001), despite higher baseline severity. Conclusions: The implementation of a structured HFNC protocol based on CRS scores is feasible in a tertiary pediatric setting, achieving high adherence (85%) and overall staff satisfaction (85.7%). While clinical outcomes remained comparable, the standardized approach encouraged early monitoring and was associated with earlier improvement in respiratory scores. Future initiatives should focus on optimizing adherence and addressing the specific concerns of senior clinical staff. bronchiolitis oxygen therapy flowchart high-flow nasal cannula non-invasive ventilation Clinical Respiratory Score pediatric ward pediatric intensive care unit Figures Figure 1 Figure 2 Figure 3 What is Known Current evidence does not support High-Flow Nasal Cannula (HFNC) as a superior first-line therapy compared to standard low-flow oxygen. However, implementing a structured hospital protocol that reserves HFNC for selected patients who fail low-flow therapy can optimize clinical management and ensure timely intervention for those in urgent need. What is new: This study demonstrates that a structured multidisciplinary protocol for HFNC - based on the Clinical Respiratory Score (CRS) and with a formal "PICU alert system"- is highly feasible in a tertiary Italian setting, achieving an overall adherence rate of 85.1%. The protocol was well-received by healthcare providers, with a global staff satisfaction rate of 85.7%. Introduction Bronchiolitis is an acute viral infection of the lower respiratory tract, characterized by inflammation and congestion of the small airways, leading to symptoms such as cough, wheezing, and difficult breathing. It is most commonly caused by respiratory syncytial virus (RSV) and it is a leading cause of hospitalizations in infants under two years of age 1 . Standard care is primarily supportive, consisting of fluid administration and oxygen therapy. In line with international standards, Italian guidelines recommend oxygen therapy if SpO2​ falls below 92%, and High-Flow Nasal Cannula (HFNC) if conventional low-flow oxygen is ineffective 2 , 3 . However, several trials have shown no significant difference between HFNC and standard care regarding key clinical outcomes, including length of hospital stay (LOS), PICU admission rates or intubation rates 4 , 5 , 6 . Despite the evidence not supporting HFNC as a first-line therapy for bronchiolitis, its use outside the PICU has surged 7 , 8 . The absence of predictive scores for HFNC efficacy complicates identifying non-responsive patients and determining when to escalate to non-invasive or invasive ventilation or when to descalate from HFNC to low flow oxygen therapy 9 , 10 . Nevertheless recent studies suggest that implementing an in-hospital HFNC protocol can improve oxygen flow initiation, accelerate weaning 11 , and could possibly reduce the need for non-invasive ventilation (NIV) or invasive mechanical ventilation 12 , 13 . At our hospital, HFNC is widely used without a standardized protocol, often as first-line therapy for bronchiolitis in both the emergency department (ED) and Pediatric Ward. Pediatric Intensive Care unit (PICU) notifications are often inconsistent, relying on individual pediatrician judgment. With frequent turnover of junior doctors, a scoring system to guide oxygen therapy for bronchiolitis patients and promptly identify severe bronchiolitis cases requiring PICU consultation or NIV would be beneficial. In response, we developed a protocol for oxygen therapy in bronchiolitis, and we applied it to patients under two years old without comorbidities admitted to the ED during the 2021–2023 winter seasons. We chose to assess the respiratory insufficiency severity with the Clinical Respiratory Score (CRS) due to its simplicity. Originally validated for asthma 14 and sickle cell anemia presenting at the ED 15 , CRS has since been largely used for pediatric respiratory distress, including bronchiolitis. The primary objective of this study was to evaluate the feasibility of the protocol by measuring healthcare staff adherence and clinician satisfaction following its implementation. As a secondary objective, we compared our data to a historical cohort of patients hospitalized for bronchiolitis during the 2017–2018 and 2018–2019 winter seasons. This analysis also aimed to determine the protocol's impact on clinical outcomes, including CRS evolution (at admission, 24h, 48h, and 72h), hospital length of stay (LOS), and PICU admission rates. Methods Setting: This quality improvement study was conducted at Meyer Children's Hospital, IRCCS, involving the ED, Pediatric Ward, and PICU. Our hospital is a university teaching facility with approximately 1500 ED admissions per year. Annually, about 250 bronchiolitis cases are admitted from the ED to the Pediatric ward and PICU. HFNC is available throughout the hospital (PICU, Pediatric ward, and ED) while NIV is available only in PICU. The study was reviewed and approved by the local Pediatric Ethics Committee (Comitato Etico Regione Toscana - Pediatrico) as a quality improvement project (No. 173/2020). The protocol, flowchart application, and data analysis were all approved. All procedures adhered to the ethical standards of the responsible committee on human experimentation and the 1975 Helsinki Declaration. In accordance with Italian legislation, only patients whose parents or legal guardians provided written informed consent for both protocol application and data collection were included. Development of the HFNC management protocol and education: In 2019, a multidisciplinary team comprising two PICU consultants, a pediatrician from the ED, and a pediatrician from the Pediatric Ward, created a clinical protocol for the management of oxygen therapy in acute bronchiolitis. It outlined, in a flowchart (Figure 1), the use of HFNC oxygen therapy in bronchiolitis cases, triggers for PICU consultation, and criteria for transferring patients to the PICU for NIV. The flowchart ( Figure 1 ) integrated criteria for initiating, implementing, or discontinuing HFNC therapy based on CRS ( Supplemental Table 1 ). The team decided to use the CRS as a guide primarily because of its simplicity and ease of application. The CRS addresses six areas: respiratory rate, auscultation, use of accessory muscle, mental status, room air SpO2, body color. The protocol was developed to minimize complexity, with the understanding that it would be implemented by staff with varying levels of knowledge and experience. The treatment recommendations were as follows: ● For CRS < 4: Administer low-flow oxygen and if the patient is on HNC, de-escalate to low-flow oxygen ● For CRS 4-5: Use HFNC at 1-2 L/kg/min with an SpO2 target of 94-95% and a maximum FiO2 of 0.5. Notify the PICU. ● For CRS 6-7: Use HFNC at 2 L/kg/min with an SpO2 target of 94-95% and a maximum FiO2 of 0.5. Consult the PICU. ● For CRS > 7: Consult the PICU and transfer the patient to intensive or semi-intensive care for NIV. The maximum flow rate for HFNC was set to 40 L/ min. The recommendation was to repeat the score at T0, T1, T2, T8, T12, T24, T48, and T72 hours after ED admission, and to continue the treatment based on the above guidelines. For PICU admissions with a CRS >7, NIV was applied per local protocol, preferably helmet continuous positive airway pressure (CPAP) with positive end expiratory pressure (PEEP) between 5 and 10 cmH2O, or bilevel NIV with a facial mask according to attending clinician preference. Weaning from HFNC was guided by repeated CRS assessments, with therapy tapered as the score decreased, transitioning through low-flow oxygen once the CRS fell below 4. Protocol education was conducted from January 2020 to October 2020.. The education plan included formal presentations of the flowchart and protocol during multiple PICU department meetings and 12 small-group sessions with the staff doctors and nurses from the Emergency and Pediatric departments. These sessions focused on explaining the flowchart, high-flow therapy application according to the CRS, and the alert system for the PICU consultation. In addition to informational presentations and email correspondence, education to clinical care teams included computer-training modules, which guided participants step-by-step through the new protocol with sample cases and videos. Paper materials were distributed to ensure easy access to the new protocol. Training was formally organized with the help of the hospital's Training Department. At the end of each winter season, several face-to-face meetings were held with the health-care staff to assess their satisfaction with the flowchart or to address any issues related to the scoring process. Satisfaction with the protocol was evaluated using a simple questionnaire with open-ended questions, stratifying the questionnaire respondents by work experience (greater or less than 5 years) and Job position (pediatricians working in the Emergency Department and inpatient wards, PICU anesthesiologists, and residents). Study Population and Data Collection: Prospective Phase (Per-Protocol Group): For the prospective arm of the study, the standardized clinical flowchart was applied to infants under 24 months of age presenting with acute bronchiolitis at the Meyer Children’s Hospital ED during two consecutive winter seasons: October 2021 to March 2022 and October 2022 to January 2023. To ensure a homogeneous study population and minimize confounding factors regarding respiratory support escalation and PICU consultation triggers, strict exclusion criteria were implemented. These included: prematurity, congenital or acquired airway anomalies, hemodynamically significant cardiac conditions, chronic respiratory diseases requiring baseline oxygen therapy, neuromuscular disorders, and a history of apnea or bradycardia requiring medical intervention. Patients were enrolled by pediatric consultants and trainees, who performed real-time CRS assessments at standardized intervals—from ED arrival up to 72 hours—and managed treatment according to the flowchart. Patients with incomplete datasets (i.e., missing scores between admission and 72 hours) were excluded from the final analysis. Retrospective Analysis (Pre-Protocol Group): A historical control group was established by reviewing medical records of infants under 2 years of age without comorbidities hospitalized for bronchiolitis during two prior winter seasons (October 2017–February 2018 and October 2018–February 2019). The following data were extracted for each patient: Demographics: Age (months) and weight (kg). Clinical Outcomes: Hospital LOS, PICU admission rates, and microbiological etiology. Respiratory Support: Modalities of oxygen therapy utilized, HFNC, NIV, and invasive mechanical ventilation. Clinical Severity: The CRS was retrospectively calculated through a comprehensive review of medical charts to determine scores at admission and at 24, 48, and 72 hours post-arrival. Process measures and Statistical Analysis: The process measure was protocol adherence, defined as the appropriate adjustment of both flow and FiO2 according to the protocol at least 85% of the time, as determined through medical records review. All clinical data are presented as mean standard deviation. Student’s t-test was applied to compare the two populations. A p-value of <0.05 was considered statistically significant. Both cohorts were considered as exploratory samples, and no formal size calculation was performed. Statistical analysis was performed using the GraphPad Prism 9.0 software package (GraphPad Software, San Diego, CA). Results Protocol Adherence and Feasibility: The flow diagram in Figure 2 presents the systematic selection of the study cohort. During the prospective study period, 456 patients presented to the ED with bronchiolitis, of whom 250 (54.8%) were hospitalized. Among these, 67 were excluded due to comorbidities and 43 due to lack of parental consent. Of the remaining 140 eligible patients (56% of admissions), 114 complete datasets were obtained, representing 45.6% of all hospitalized cases. Out of 114 enrolled patients, 97 successfully completed the study according to the protocol requirements, demonstrating an overall adherence rate during the first 72 hours of hospitalization of 85.1%. Seventeen patients (14.9%) were excluded from the primary analysis due to protocol deviations based on attending physician judgment; specifically, these patients were treated as "off-protocol" with HFNC flow rates set below 1 L/kg/min despite having Clinical Respiratory Scores (CRS) > 4, which required a flow of 2 L/kg/min. Demographic characteristics of the per protocol populations are described in table 1. Clinician Satisfaction: Satisfaction survey results ( Table 1 ) included responses from 35 clinicians. Pediatric residents (n=5) and junior physicians (n=15) reported a satisfaction rate of 100%. Senior physicians reported a satisfaction rate of 70% (10/15). The overall satisfaction rate was 85.7%. Demographic and Clinical Characteristics Table 2 describes and compares the demographic characteristics of the per-protocol (N=97) and pre-protocol (N=86) groups. During the retrospective study period, 374 patients presented with bronchiolitis symptoms, 145 were admitted, and 86 were included in the final analysis after applying exclusion criteria and verifying data completeness. Univariate analysis showed differences in age and weight between the cohorts (p=0.047 and p=0.021, respectively). In the per-protocol group, viral etiology was identified as RSV in 65% (n=63), co-infections in 20.6% (n=20), Bocavirus in 6.2% (n=6), and unknown in 8.2% (n=8). In the pre-protocol group, RSV alone was identified in 69% (n=60) cases and RSV co-infection in 28% (n=24) cases. There were no statistically significant differences in etiological distribution between the groups. The hospital length of stay (LOS) was 6.13 ± 2.60 days in the per-protocol group and 7.12 ± 8.95 days in the pre-protocol group (p=0.303). PICU admission occurred in 20.6% (n=20) of the per-protocol group and 11.6% (n=10) of the pre-protocol group (p=0.150). NIV was utilized in 18.6% (n=18) of the per-protocol group and 5.8% (n=5) of the pre-protocol group (p=0.018). Invasive mechanical ventilation was required for 2 patients (2.1%) in the per-protocol group and 5 patients (5.8%) in the pre-protocol group (p=0.350). CRS Evolution: Table 3 presents the CRS values over time of the per-protocol and pre-protocol groups . At admission (T0), the per-protocol group had a mean CRS of 4.57 ± 1.67 compared to 2.35 ± 1.49 in the pre-protocol group (p < 0.001). At 24 hours (T24), scores were 2.96 ± 1.46 and 3.11 ± 1.41, respectively (p = 0.492). At 48 hours (T48), CRS values were 2.46 ± 1.44 for the per-protocol group and 3.25 ± 1.82 for the pre-protocol group (p = 0.001). At 72 hours (T72), scores were 1.91 ± 1.37 and 3.05 ± 1.98, respectively (p < 0.001). The chart in Figure 3 displays the clinical course of patients, including the CRS at 2h and at 8h monitoring points for the per-protocol group. Discussion This quality improvement initiative assessed the implementation of a standardized HFNC protocol for infants with bronchiolitis at an Italian Hospital. The data indicate that the application of this flowchart is feasible, achieving an 85.1% adherence rate within the first 72 hours of hospitalization, which suggests a consistent integration of the protocol into routine clinical practice. Analysis of staff feedback revealed a high level of overall satisfaction (approximately 87%). However, satisfaction levels diverged significantly based on clinical experience. While the protocol reached universal acceptance among residents and junior physicians (100%), senior clinicians reported a lower satisfaction rate of 70%. This disparity may reflect a greater reliance on individual clinical judgment among more experienced staff, or perhaps a more critical perspective on the implementation of standardized constraints compared to traditional, experience-based practices. The CRS was selected for this protocol due to its clinical simplicity and the current lack of evidence favoring alternative scales for assessing disease severity 9 . By providing clear guidelines based on a simple score as CRS for treatment escalation - particularly within the ED- the protocol offered guidance for junior physicians, fostering more consistent clinical decision-making. The protocol sought to implement a standardized alert system for PICU consultation; such clarity was particularly appreciated by junior physicians. Regarding population characteristics, a significant difference was observed in baseline severity scores upon ED arrival (T0). The per-protocol group presented with significantly higher (worse) CRS scores compared to the p-protocol cohort (4.57 ± 1.67 vs. 2.35 ± 1.49, p < 0.001). No significant differences were observed in the total length of hospital stay (p = 0.303) or the rate of PICU admissions (p = 0.150), consistent with previous reports in the literature 4 , 5 , 6 . However, a significantly higher utilization of NIV was recorded in the per-protocol group (18.6% vs 5.8%, p = 0.018), a finding that aligns with the higher baseline severity documented at admission. However, the incidence of invasive mechanical ventilation remained low and comparable between the two study periods (2.1% vs 5.8%, p = 0.350), suggesting that the more complex per-protocol group was effectively managed according to the protocol. In line with the literature, we observed a shift in care patterns toward increased intensity, marked by higher rates of PICU admissions and a rising use of non-invasive ventilation 16 , 17 . This may potentially reflect a more standardized alerting process for the PICU consultant, which could have allowed for a more focused clinical attention on high-risk patients. Concerning the evolution of the CRS, despite the initial difference of baseline severity, no significant difference was observed at 24 hours. Furthermore, an improvement in scores was observed in the per-protocol group at 48 and 72 hours compared to the historical retrospective cohort showing that patients managed under the new protocol exhibited a more pronounced and rapid clinical recovery (Fig. 3 ). The per-protocol group included additional early assessment points at 2 and 8 hours to monitor initial stabilization and we speculate that this further evaluation moments may have contributed to adjust the timely respiratory support in analyzed children. Limitations: Due to the limited sample size analyzed and the matched controlled methodology, these observations regarding clinical trends and the protocol’s role in facilitating patient stabilization must be interpreted with caution. The retrospective cohort may have failed to capture more severe cases with rapid clinical progression and early PICU admission, which may partly explain the differences in baseline scores. Further validation in larger prospective cohorts is required. The satisfaction survey was administered only to a subset of the medical staff (pediatricians, anesthesiologists and trainees) who were actively involved in data collection and recruitment. This selection bias may have overestimated the overall satisfaction rate. Staffing shortages impacted enrollment. For instance, informed consent was often not obtained during night shifts, leading to the exclusion of potentially eligible patients. Conclusion Our findings suggest that the implementation of a standardized HFNC protocol for infants with acute bronchiolitis is simple and feasible and may result in a high adherence within a tertiary pediatric care setting in Italy. In children admitted to ED for bronchiolitis, the protocol-driven approach was associated with a more structured monitoring of respiratory distress. While clinical outcomes remained comparable, the standardized approach encouraged timely assessment and was associated with earlier improvement in respiratory scores. These findings provide a preliminary basis for the use of objective clinical scores (CRS) to guide HFNC therapy, but further large-scale, prospective studies are necessary to confirm whether these standardized interventions directly improve clinical outcomes. Abbreviations PICU: Pediatric Intensive Care Unit HFNC: High Flow Nasal Cannula CRS: Clinical Respiratory Score NIV: Non-invasive ventilation RSV: respiratory syncytial virus ED: Emergency Department Declarations All the authors of this article contributed equally to the 14 roles defined by the CRediT taxonomy. Each author accepts responsibility for the manuscript’s data, analysis, and conclusions, as prescribed by the International Committee of Medical Journal Editors (ICMJE). Financial Disclosure Statement for all Authors: The Authors have no financial relationship regarding this article to disclose. Funding source: None Potential Conflicts of Interest for all Authors: The Authors have no conflicts of interest regarding this article to disclose. Author Contribution All the authors of this article contributed equally to the 14 roles defined by the CRediT taxonomy.Each author accepts responsibility for the manuscript’s data, analysis, and conclusions, as prescribed by the International Committee of Medical Journal Editors (ICMJE). References Langley JM, Halley T, Kalburgi S et al (2022) Incidence of Respiratory Syncytial Virus Lower Respiratory Tract Infections During the First 2 Years of Life: A Prospective Study Across Diverse Global Settings. J Infect Dis 226(3):374–385. 10.1093/infdis/jiac227 Kirolos A, Bahl R, Balakrishnan S et al (2020) A Systematic Review of Clinical Practice Guidelines for the Diagnosis and Management of Bronchiolitis. 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JAMA Pediatr 176(3):270–279. 10.1001/ jamapediatrics.2021.517 Tables Table 1 : Clinician Satisfaction with protocol and Experience Level (years of Job experience) Professional Category Years of Experience N Full Satisfaction (Yes) Medical Residents In training 5 100% (5/5) Junior Physicians < 5 years 15 100% (15/15) Senior Physicians ≥ 5 years 15 70% (10/15) Total - 35 85.7% (30/35) Table 2. Demographic and Clinical Characteristics of Patient Groups Pre-protocol(N=86) and Per-protocol(N=97). *LOS Lenght of stay in Hospital, ** NIV Non invasive ventilation, ***VAM Mechanical Ventilation Pre-protocol (N=86) Per-protocol (N=97) p-value Age (months) , mean ± SD 5.10 ± 5.35 6.96 ± 6.94 — Weight (kg) , mean ± SD 6.09 ± 2.41 7.05 ± 3.04 — Sex (Male) , n (%) 49 (57.0%) 60 (61.9%) 0.603 LOS* (days) , mean ± SD 7.12 ± 8.95 6.13 ± 2.60 0.303 PICU Admission , n (%) 10 (11.6%) 20 (20.6%) 0.150 NIV**, n (%) 5 (5,8%) 18 (18.6%) 0.018 VAM**, n(%) 5 (5.8%) 2 (2.1%) 0.350 Viral Etiology (Overall) 0.024 Table 3. Comparison of Clinical Respiratory Scores (CRS) Between Study Cohorts. Data are presented as Mean and Interquartile Range (IQR: 25th–75th percentiles). The table compares the respiratory distress levels of the Pre-Protocol cohort (October 2017 – February 2019) and the Per-Protocol cohort (2021–2022) at baseline and subsequent time points. Statistical significance was set at p < 0.05. Time Point Pre-Protocol Mean Pre-Protocol IQR (Q1-Q3) Per-Protocol Mean Per-Protocol IQR (Q1-Q3) p-value (Mann-Whitney) Baseline (T0) 2.35 1.00 - 3.00 4.57 4.00 - 5.00 < 0.0001 24 Ore 3.11 2.00 - 4.00 2.96 2.00 - 4.00 0.5397 48 Ore 3.25 2.00 - 4.00 2.46 2.00 - 3.00 0.0008 72 Ore 3.05 2.00 - 4.00 1.91 1.00 - 3.00 < 0.0001 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 03 Apr, 2026 Reviews received at journal 29 Mar, 2026 Reviewers agreed at journal 27 Mar, 2026 Reviewers invited by journal 27 Mar, 2026 Editor assigned by journal 27 Mar, 2026 Submission checks completed at journal 26 Mar, 2026 First submitted to journal 18 Mar, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-9159619","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":614064209,"identity":"2f1a7e1b-f554-4e30-aa06-d727e5010c38","order_by":0,"name":"Cristina Giugni","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABCUlEQVRIiWNgGAWjYFACxgYGBgMYg0FCDiosgV/LASQtxjAt+PQwMBxAYic2ELKGf/bh5s8fCu7IM/AvbpP8usMifW17j+HjCgaLOlxaJM4ltkkcMHhm2CDxsE1a9oxE7rYzZ4wNz+BxmAEPYxvQL4cZGyQOtklLtgG13Mgxk2zAr6X5A1CLPUxLutn9N+Y/CWhpADrscGIDf2Ob5Mc2iQSzGzxmjPi0SJxhbJM4Y3A4uU2CsdkayDbcdiatWLLBQALoOOyAv4f98YeKP4dt+/mPP7z5s61O3uz44Y0fGyrq+HHZAgdsEgkMzDxgJocBND0QAvwHGBh/gFnsD4hRPwpGwSgYBSMHAADK01WttZKPagAAAABJRU5ErkJggg==","orcid":"","institution":"Meyer Children's Hospital IRCSS","correspondingAuthor":true,"prefix":"","firstName":"Cristina","middleName":"","lastName":"Giugni","suffix":""},{"id":614064210,"identity":"afbe1d19-4786-4eb4-b485-edf577acdf37","order_by":1,"name":"Costanza Cecchi","email":"","orcid":"","institution":"Meyer Children's Hospital IRCSS","correspondingAuthor":false,"prefix":"","firstName":"Costanza","middleName":"","lastName":"Cecchi","suffix":""},{"id":614064211,"identity":"854a4c49-e382-410a-83d5-dde941d79f0a","order_by":2,"name":"Laura Nanni","email":"","orcid":"","institution":"Meyer Children's Hospital IRCSS","correspondingAuthor":false,"prefix":"","firstName":"Laura","middleName":"","lastName":"Nanni","suffix":""},{"id":614064212,"identity":"3b79650a-0113-431a-92c9-3cce9ec512c9","order_by":3,"name":"Zaccaria Ricci","email":"","orcid":"","institution":"University of Florence","correspondingAuthor":false,"prefix":"","firstName":"Zaccaria","middleName":"","lastName":"Ricci","suffix":""}],"badges":[],"createdAt":"2026-03-18 12:54:12","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9159619/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9159619/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":105874733,"identity":"33f6c06b-a3d8-42d1-abf8-fd621f1c19ff","added_by":"auto","created_at":"2026-04-01 05:31:44","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":70278,"visible":true,"origin":"","legend":"\u003cp\u003eFlowchart for oxygen administration, HFNC initiation and descalation, PICU consultation criteria within the clinical protocol for bronchiolitis in infants under 2 years of age.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-9159619/v1/b80cd18d1c0f5156bead0cca.png"},{"id":105905539,"identity":"2838b3f1-5da0-4524-8c12-75fdb6d9e98a","added_by":"auto","created_at":"2026-04-01 10:12:43","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":174871,"visible":true,"origin":"","legend":"\u003cp\u003eFlow diagram of patient recruitment showing the systematic selection of the study cohort. Starting from 456 patients at the Emergency Department, the process details the admission of 250 patients, the exclusion criteria that led to 150 eligible subjects, the removal of cases with incomplete data (n=36), and finally, the exclusion of patients non-adherent to the protocol (n=17). This resulted in a definitive Per-Protocol analysis group of 97 patients.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-9159619/v1/0bb953b8d77bd6b3015d7ff5.png"},{"id":105874734,"identity":"489eb725-93ad-4e06-8ed7-6b20e30b0ac4","added_by":"auto","created_at":"2026-04-01 05:31:45","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":119969,"visible":true,"origin":"","legend":"\u003cp\u003eLongitudinal Comparison of Clinical Respiratory Scores (CRS) between Pre-Protocol and Per-Protocol populations. Data points represent the Mean score, while the shaded regions/error bars represent the \u003cstrong\u003eInterquartile Range (IQR, Q1–Q3)\u003c/strong\u003e. The Per-Protocol group shows a steeper decline in respiratory distress despite higher baseline scores. Significance levels: p \u0026lt; 0.05 at T0, 48h, and 72h.\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-9159619/v1/979ad00bb5ff3589c01f8cfb.png"},{"id":105906795,"identity":"d6fb965a-b161-4c31-a1aa-174ac2b9cca0","added_by":"auto","created_at":"2026-04-01 10:24:58","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1252796,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9159619/v1/cda70a77-9951-4564-b717-5dceecd5ce1e.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"High Flow Nasal Cannula Therapy in Acute Bronchiolitis: an Italian Children’s Hospital Protocol","fulltext":[{"header":"What is Known","content":"\u003cp\u003eCurrent evidence does not support High-Flow Nasal Cannula (HFNC) as a superior first-line therapy compared to standard low-flow oxygen. However, implementing a structured hospital protocol that reserves HFNC for selected patients who fail low-flow therapy can optimize clinical management and ensure timely intervention for those in urgent need.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat is new:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study demonstrates that a structured multidisciplinary protocol for HFNC - based on the Clinical Respiratory Score (CRS) and with a formal \u0026quot;PICU alert system\u0026quot;- is highly feasible in a tertiary Italian setting, achieving an overall adherence rate of 85.1%. The protocol was well-received by healthcare providers, with a global staff satisfaction rate of 85.7%.\u003c/p\u003e"},{"header":"Introduction","content":"\u003cp\u003eBronchiolitis is an acute viral infection of the lower respiratory tract, characterized by inflammation and congestion of the small airways, leading to symptoms such as cough, wheezing, and difficult breathing. It is most commonly caused by respiratory syncytial virus (RSV) and it is a leading cause of hospitalizations in infants under two years of age\u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u003c/sup\u003e. Standard care is primarily supportive, consisting of fluid administration and oxygen therapy. In line with international standards, Italian guidelines recommend oxygen therapy if SpO2​ falls below 92%, and High-Flow Nasal Cannula (HFNC) if conventional low-flow oxygen is ineffective\u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e,\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u003c/sup\u003e. However, several trials have shown no significant difference between HFNC and standard care regarding key clinical outcomes, including length of hospital stay (LOS), PICU admission rates or intubation rates\u003csup\u003e\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e,\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e,\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u003c/sup\u003e. Despite the evidence not supporting HFNC as a first-line therapy for bronchiolitis, its use outside the PICU has surged\u003csup\u003e\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e,\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u003c/sup\u003e. The absence of predictive scores for HFNC efficacy complicates identifying non-responsive patients and determining when to escalate to non-invasive or invasive ventilation or when to descalate from HFNC to low flow oxygen therapy\u003csup\u003e\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e,\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u003c/sup\u003e. Nevertheless recent studies suggest that implementing an in-hospital HFNC protocol can improve oxygen flow initiation, accelerate weaning\u003csup\u003e\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/sup\u003e, and could possibly reduce the need for non-invasive ventilation (NIV) or invasive mechanical ventilation\u003csup\u003e\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e,\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eAt our hospital, HFNC is widely used without a standardized protocol, often as first-line therapy for bronchiolitis in both the emergency department (ED) and Pediatric Ward. Pediatric Intensive Care unit (PICU) notifications are often inconsistent, relying on individual pediatrician judgment. With frequent turnover of junior doctors, a scoring system to guide oxygen therapy for bronchiolitis patients and promptly identify severe bronchiolitis cases requiring PICU consultation or NIV would be beneficial. In response, we developed a protocol for oxygen therapy in bronchiolitis, and we applied it to patients under two years old without comorbidities admitted to the ED during the 2021\u0026ndash;2023 winter seasons. We chose to assess the respiratory insufficiency severity with the Clinical Respiratory Score (CRS) due to its simplicity. Originally validated for asthma\u003csup\u003e\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u003c/sup\u003e and sickle cell anemia presenting at the ED\u003csup\u003e15\u003c/sup\u003e, CRS has since been largely used for pediatric respiratory distress, including bronchiolitis.\u003c/p\u003e \u003cp\u003eThe primary objective of this study was to evaluate the feasibility of the protocol by measuring healthcare staff adherence and clinician satisfaction following its implementation. As a secondary objective, we compared our data to a historical cohort of patients hospitalized for bronchiolitis during the 2017\u0026ndash;2018 and 2018\u0026ndash;2019 winter seasons. This analysis also aimed to determine the protocol's impact on clinical outcomes, including CRS evolution (at admission, 24h, 48h, and 72h), hospital length of stay (LOS), and PICU admission rates.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003e\u003cstrong\u003eSetting:\u0026nbsp;\u003c/strong\u003eThis quality improvement study was conducted at Meyer Children\u0026apos;s Hospital, IRCCS, involving the ED, Pediatric Ward, and PICU. Our hospital is a university teaching facility with approximately 1500 ED admissions per year. Annually, about 250 bronchiolitis cases are admitted from the ED to the Pediatric ward and PICU. HFNC is available throughout the hospital (PICU, Pediatric ward, and ED) while NIV is available only in PICU.\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003eThe study was reviewed and approved by the local Pediatric Ethics Committee (Comitato Etico Regione Toscana - Pediatrico) as a quality improvement project (No. 173/2020). The protocol, flowchart application, and data analysis were all approved. All procedures adhered to the ethical standards of the responsible committee on human experimentation and the 1975 Helsinki Declaration. In accordance with Italian legislation, only patients whose parents or legal guardians provided written informed consent for both protocol application and data collection were included.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDevelopment of the HFNC management protocol and education:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn 2019, a multidisciplinary team comprising two PICU consultants, a pediatrician from the ED, and a pediatrician from the Pediatric Ward, created a clinical protocol for the management of oxygen therapy in acute bronchiolitis. It outlined, in a flowchart (Figure 1), the use of HFNC oxygen therapy in bronchiolitis cases, triggers for PICU consultation, and criteria for transferring patients to the PICU for NIV. \u0026nbsp; The flowchart (\u003cstrong\u003eFigure 1\u003c/strong\u003e) integrated criteria for initiating, implementing, or discontinuing HFNC therapy based on CRS (\u003cstrong\u003eSupplemental Table 1\u003c/strong\u003e). The team decided to use the CRS as a guide primarily because of its simplicity and ease of application. The CRS addresses six areas: respiratory rate, auscultation, use of accessory muscle, mental status, room air SpO2, body color. The protocol was developed to minimize complexity, with the understanding that it would be implemented by staff with varying levels of knowledge and experience.\u003c/p\u003e\n\u003cp\u003eThe treatment recommendations were as follows:\u003c/p\u003e\n\u003cp\u003e● \u0026nbsp;For CRS \u0026lt; 4: Administer low-flow oxygen and if the patient is on HNC, de-escalate to low-flow oxygen\u003c/p\u003e\n\u003cp\u003e● \u0026nbsp;For CRS 4-5: Use HFNC at 1-2 L/kg/min with an SpO2 target of 94-95% and a maximum FiO2 of 0.5. Notify the PICU.\u003c/p\u003e\n\u003cp\u003e● \u0026nbsp;For CRS 6-7: Use HFNC at 2 L/kg/min with an SpO2 target of 94-95% and a maximum FiO2 of 0.5. Consult the PICU.\u003c/p\u003e\n\u003cp\u003e● \u0026nbsp;For CRS \u0026gt; 7: Consult the PICU and transfer the patient to intensive or semi-intensive care for NIV.\u003c/p\u003e\n\u003cp\u003eThe maximum flow rate for HFNC was set to 40 L/ min. The recommendation was to repeat the score at T0, T1, T2, T8, T12, T24, T48, and T72 hours after ED admission, and to continue the treatment based on the above guidelines. For PICU admissions with a CRS \u0026gt;7, NIV was applied per local protocol, preferably helmet continuous positive airway pressure (CPAP) with positive end expiratory pressure (PEEP) between 5 and 10 cmH2O, or bilevel NIV with a facial mask according to attending clinician preference. Weaning from HFNC was guided by repeated CRS assessments, with therapy tapered as the score decreased, transitioning through low-flow oxygen once the CRS fell below 4. Protocol education was conducted from January 2020 to October 2020.. The education plan included formal presentations of the flowchart and protocol during multiple PICU department meetings and 12 small-group sessions with the staff doctors and nurses from the Emergency and Pediatric departments. These sessions focused on explaining the flowchart, high-flow therapy application according to the CRS, and the alert system for the PICU consultation. In addition to informational presentations and email correspondence, education to clinical care teams included computer-training modules, which guided participants step-by-step through the new protocol with sample cases and videos. Paper materials were distributed to ensure easy access to the new protocol. Training was formally organized with the help of the hospital\u0026apos;s Training Department. At the end of each winter season, several face-to-face meetings were held with the health-care staff to assess their satisfaction with the flowchart or to address any issues related to the scoring process. Satisfaction with the protocol was evaluated using a simple questionnaire with open-ended questions, stratifying the questionnaire respondents by work experience (greater or less than 5 years) and Job position (pediatricians working in the Emergency Department and inpatient wards, PICU anesthesiologists, and residents).\u003c/p\u003e\n\u003ch3\u003e\u003cstrong\u003eStudy Population and Data Collection:\u003c/strong\u003e\u003c/h3\u003e\n\u003ch4\u003e\u003cstrong\u003eProspective Phase (Per-Protocol Group):\u003c/strong\u003e\u003c/h4\u003e\n\u003cp\u003eFor the prospective arm of the study, the standardized clinical flowchart was applied to infants under 24 months of age presenting with acute bronchiolitis at the Meyer Children\u0026rsquo;s Hospital ED during two consecutive winter seasons: October 2021 to March 2022 and October 2022 to January 2023. To ensure a homogeneous study population and minimize confounding factors regarding respiratory support escalation and PICU consultation triggers, strict exclusion criteria were implemented. These included: prematurity, congenital or acquired airway anomalies, hemodynamically significant cardiac conditions, chronic respiratory diseases requiring baseline oxygen therapy, neuromuscular disorders, and a history of apnea or bradycardia requiring medical intervention. Patients were enrolled by pediatric consultants and trainees, who performed real-time CRS assessments at standardized intervals\u0026mdash;from ED arrival up to 72 hours\u0026mdash;and managed treatment according to the flowchart. Patients with incomplete datasets (i.e., missing scores between admission and 72 hours) were excluded from the final analysis.\u003c/p\u003e\n\u003ch4\u003e\u003cstrong\u003eRetrospective Analysis (Pre-Protocol Group):\u003c/strong\u003e\u003c/h4\u003e\n\u003cp\u003eA historical control group was established by reviewing medical records of infants under 2 years of age without comorbidities hospitalized for bronchiolitis during two prior winter seasons (October 2017\u0026ndash;February 2018 and October 2018\u0026ndash;February 2019).\u003c/p\u003e\n\u003cp\u003eThe following data were extracted for each patient:\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003eDemographics: Age (months) and weight (kg).\u003c/li\u003e\n \u003cli\u003eClinical Outcomes: Hospital LOS, PICU admission rates, and microbiological etiology.\u003c/li\u003e\n \u003cli\u003eRespiratory Support: Modalities of oxygen therapy utilized, HFNC, NIV, and invasive mechanical ventilation.\u003c/li\u003e\n \u003cli\u003eClinical Severity: The CRS was retrospectively calculated through a comprehensive review of medical charts to determine scores at admission and at 24, 48, and 72 hours post-arrival.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003e\u003cstrong\u003eProcess measures and Statistical Analysis:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe process measure was protocol adherence, defined as the appropriate adjustment of both flow and FiO2 according to the protocol at least 85% of the time, as determined through medical records review. \u0026nbsp;All clinical data are presented as mean standard deviation. Student\u0026rsquo;s t-test was applied to compare the two populations. A p-value of \u0026lt;0.05 was considered statistically significant. Both cohorts were considered as exploratory samples, and no formal size calculation was performed. Statistical analysis was performed using the GraphPad Prism 9.0 software package (GraphPad Software, San Diego, CA).\u003c/p\u003e"},{"header":"Results","content":"\u003ch4\u003e\u003cstrong\u003eProtocol Adherence and Feasibility:\u003c/strong\u003e\u003c/h4\u003e\n\u003cp\u003eThe flow diagram in Figure 2 presents the systematic selection of the study cohort. \u0026nbsp;During the prospective study period, 456 patients presented to the ED with bronchiolitis, of whom 250 (54.8%) were hospitalized. Among these, 67 were excluded due to comorbidities and 43 due to lack of parental consent. Of the remaining 140 eligible patients (56% of admissions), 114 complete datasets were obtained, representing 45.6% of all hospitalized cases. Out of 114 enrolled patients, 97 successfully completed the study according to the protocol requirements, demonstrating an overall adherence rate during the first 72 hours of hospitalization of 85.1%. Seventeen patients (14.9%) were excluded from the primary analysis due to protocol deviations based on attending physician judgment; specifically, these patients were treated as \u0026quot;off-protocol\u0026quot; with HFNC flow rates set below 1 L/kg/min despite having Clinical Respiratory Scores (CRS) \u0026gt; 4, which required a flow of 2 L/kg/min. Demographic characteristics of the per protocol populations are described in table 1.\u003c/p\u003e\n\u003ch4\u003e\u003cstrong\u003eClinician Satisfaction:\u003c/strong\u003e\u003c/h4\u003e\n\u003cp\u003eSatisfaction survey results (\u003cstrong\u003eTable 1\u003c/strong\u003e) included responses from 35 clinicians. Pediatric residents (n=5) and junior physicians (n=15) reported a satisfaction rate of 100%. Senior physicians reported a satisfaction rate of 70% (10/15). The overall satisfaction rate was 85.7%.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDemographic and Clinical Characteristics\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 2\u003c/strong\u003e describes and compares the demographic characteristics of the per-protocol (N=97) and pre-protocol (N=86) groups. During the retrospective study period, 374 patients presented with bronchiolitis symptoms, 145 were admitted, and 86 were included in the final analysis after applying exclusion criteria and verifying data completeness. Univariate analysis showed differences in age and weight between the cohorts (p=0.047 and p=0.021, respectively). In the per-protocol group, viral etiology was identified as RSV in 65% (n=63), co-infections in 20.6% (n=20), Bocavirus in 6.2% (n=6), and unknown in 8.2% (n=8). In the pre-protocol group, RSV alone was identified in 69% (n=60) cases and RSV co-infection in 28% (n=24) cases. There were no statistically significant differences in etiological distribution between the groups. The hospital length of stay (LOS) was 6.13\u0026nbsp;\u0026plusmn;\u0026nbsp;2.60 days in the per-protocol group and 7.12\u0026nbsp;\u0026plusmn;\u0026nbsp;8.95 days in the pre-protocol group (p=0.303). PICU admission occurred in 20.6% (n=20) of the per-protocol group and 11.6% (n=10) of the pre-protocol group (p=0.150). NIV was utilized in 18.6% (n=18) of the per-protocol group and 5.8% (n=5) of the pre-protocol group (p=0.018). Invasive mechanical ventilation was required for 2 patients (2.1%) in the per-protocol group and 5 patients (5.8%) in the pre-protocol group (p=0.350).\u003c/p\u003e\n\u003ch4\u003e\u003cstrong\u003eCRS Evolution:\u003c/strong\u003e\u003c/h4\u003e\n\u003cp\u003e\u003cstrong\u003eTable 3\u003c/strong\u003e presents the CRS values over time of the per-protocol and pre-protocol groups . At admission (T0), the per-protocol group had a mean CRS of 4.57\u0026nbsp;\u0026plusmn;\u0026nbsp;1.67 compared to 2.35\u0026nbsp;\u0026plusmn;\u0026nbsp;1.49 in the pre-protocol group (p \u0026lt; 0.001). At 24 hours (T24), scores were 2.96\u0026nbsp;\u0026plusmn;\u0026nbsp;1.46 and 3.11\u0026nbsp;\u0026plusmn;\u0026nbsp;1.41, respectively (p = 0.492). At 48 hours (T48), CRS values were 2.46\u0026nbsp;\u0026plusmn;\u0026nbsp;1.44 for the per-protocol group and 3.25\u0026nbsp;\u0026plusmn;\u0026nbsp;1.82 for the pre-protocol group (p = 0.001). At 72 hours (T72), scores were 1.91\u0026nbsp;\u0026plusmn;\u0026nbsp;1.37 and 3.05\u0026nbsp;\u0026plusmn;\u0026nbsp;1.98, respectively (p \u0026lt; 0.001). The chart in \u003cstrong\u003eFigure 3\u003c/strong\u003e displays the clinical course of patients, including the CRS at 2h and at 8h monitoring points for the per-protocol group.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis quality improvement initiative assessed the implementation of a standardized HFNC protocol for infants with bronchiolitis at an Italian Hospital. The data indicate that the application of this flowchart is feasible, achieving an 85.1% adherence rate within the first 72 hours of hospitalization, which suggests a consistent integration of the protocol into routine clinical practice. Analysis of staff feedback revealed a high level of overall satisfaction (approximately 87%). However, satisfaction levels diverged significantly based on clinical experience. While the protocol reached universal acceptance among residents and junior physicians (100%), senior clinicians reported a lower satisfaction rate of 70%. This disparity may reflect a greater reliance on individual clinical judgment among more experienced staff, or perhaps a more critical perspective on the implementation of standardized constraints compared to traditional, experience-based practices. The CRS was selected for this protocol due to its clinical simplicity and the current lack of evidence favoring alternative scales for assessing disease severity\u003csup\u003e\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u003c/sup\u003e. By providing clear guidelines based on a simple score as CRS for treatment escalation - particularly within the ED- the protocol offered guidance for junior physicians, fostering more consistent clinical decision-making. The protocol sought to implement a standardized alert system for PICU consultation; such clarity was particularly appreciated by junior physicians.\u003c/p\u003e \u003cp\u003eRegarding population characteristics, a significant difference was observed in baseline severity scores upon ED arrival (T0). The per-protocol group presented with significantly higher (worse) CRS scores compared to the p-protocol cohort (4.57\u0026thinsp;\u0026plusmn;\u0026thinsp;1.67 vs. 2.35\u0026thinsp;\u0026plusmn;\u0026thinsp;1.49, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). No significant differences were observed in the total length of hospital stay (p\u0026thinsp;=\u0026thinsp;0.303) or the rate of PICU admissions (p\u0026thinsp;=\u0026thinsp;0.150), consistent with previous reports in the literature\u003csup\u003e\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e,\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e,\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u003c/sup\u003e. However, a significantly higher utilization of NIV was recorded in the per-protocol group (18.6% vs 5.8%, p\u0026thinsp;=\u0026thinsp;0.018), a finding that aligns with the higher baseline severity documented at admission. However, the incidence of invasive mechanical ventilation remained low and comparable between the two study periods (2.1% vs 5.8%, p\u0026thinsp;=\u0026thinsp;0.350), suggesting that the more complex per-protocol group was effectively managed according to the protocol. In line with the literature, we observed a shift in care patterns toward increased intensity, marked by higher rates of PICU admissions and a rising use of non-invasive ventilation\u003csup\u003e\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e,\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e\u003c/sup\u003e. This may potentially reflect a more standardized alerting process for the PICU consultant, which could have allowed for a more focused clinical attention on high-risk patients.\u003c/p\u003e \u003cp\u003eConcerning the evolution of the CRS, despite the initial difference of baseline severity, no significant difference was observed at 24 hours. Furthermore, an improvement in scores was observed in the per-protocol group at 48 and 72 hours compared to the historical retrospective cohort showing that patients managed under the new protocol exhibited a more pronounced and rapid clinical recovery (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). The per-protocol group included additional early assessment points at 2 and 8 hours to monitor initial stabilization and we speculate that this further evaluation moments may have contributed to adjust the timely respiratory support in analyzed children.\u003c/p\u003e \u003cdiv id=\"Sec14\" class=\"Section2\"\u003e \u003ch2\u003eLimitations:\u003c/h2\u003e \u003cp\u003eDue to the limited sample size analyzed and the matched controlled methodology, these observations regarding clinical trends and the protocol\u0026rsquo;s role in facilitating patient stabilization must be interpreted with caution. The retrospective cohort may have failed to capture more severe cases with rapid clinical progression and early PICU admission, which may partly explain the differences in baseline scores. Further validation in larger prospective cohorts is required. The satisfaction survey was administered only to a subset of the medical staff (pediatricians, anesthesiologists and trainees) who were actively involved in data collection and recruitment. This selection bias may have overestimated the overall satisfaction rate. Staffing shortages impacted enrollment. For instance, informed consent was often not obtained during night shifts, leading to the exclusion of potentially eligible patients.\u003c/p\u003e \u003c/div\u003e"},{"header":"Conclusion","content":"\u003cp\u003eOur findings suggest that the implementation of a standardized HFNC protocol for infants with acute bronchiolitis is simple and feasible and may result in a high adherence within a tertiary pediatric care setting in Italy. In children admitted to ED for bronchiolitis, the protocol-driven approach was associated with a more structured monitoring of respiratory distress. While clinical outcomes remained comparable, the standardized approach encouraged timely assessment and was associated with earlier improvement in respiratory scores. \u0026nbsp; These findings provide a preliminary basis for the use of objective clinical scores (CRS) to guide HFNC therapy, but further large-scale, prospective studies are necessary to confirm whether these standardized interventions directly improve clinical outcomes.\u003c/p\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003ePICU: Pediatric Intensive Care Unit\u003c/p\u003e\n\u003cp\u003eHFNC: High Flow Nasal Cannula\u003c/p\u003e\n\u003cp\u003eCRS: Clinical Respiratory Score\u003c/p\u003e\n\u003cp\u003eNIV: Non-invasive ventilation\u003c/p\u003e\n\u003cp\u003eRSV:\u0026nbsp;respiratory syncytial virus\u003c/p\u003e\n\u003cp\u003eED: Emergency Department\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003eAll the authors of this article contributed equally to the 14 roles defined by the CRediT taxonomy.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eEach author accepts responsibility for the manuscript\u0026rsquo;s data, analysis, and conclusions, as prescribed by the International Committee of Medical Journal Editors (ICMJE).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFinancial Disclosure Statement for all Authors:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe Authors have no financial relationship regarding this article to disclose.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding source:\u003c/strong\u003e None\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePotential Conflicts of Interest for all Authors:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe Authors have no conflicts of interest regarding this article to disclose.\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eAll the authors of this article contributed equally to the 14 roles defined by the CRediT taxonomy.Each author accepts responsibility for the manuscript\u0026rsquo;s data, analysis, and conclusions, as prescribed by the International Committee of Medical Journal Editors (ICMJE).\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eLangley JM, Halley T, Kalburgi S et al (2022) Incidence of Respiratory Syncytial Virus Lower Respiratory Tract Infections During the First 2 Years of Life: A Prospective Study Across Diverse Global Settings. 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JAMA Pediatr 176(3):270\u0026ndash;279. 10.1001/ jamapediatrics.2021.517\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003e\u003cstrong\u003eTable 1\u003c/strong\u003e: Clinician Satisfaction with protocol and Experience Level (years of Job experience)\u0026nbsp;\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"553\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 166px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eProfessional Category\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 155px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eYears of Experience\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 69px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eN\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 163px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eFull Satisfaction (Yes)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 166px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eMedical Residents\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 155px;\"\u003e\n \u003cp\u003eIn training\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 69px;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 163px;\"\u003e\n \u003cp\u003e100% (5/5)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 166px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eJunior Physicians\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 155px;\"\u003e\n \u003cp\u003e\u0026lt; 5 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 69px;\"\u003e\n \u003cp\u003e15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 163px;\"\u003e\n \u003cp\u003e100% (15/15)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 166px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eSenior Physicians\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 155px;\"\u003e\n \u003cp\u003e\u0026ge; 5 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 69px;\"\u003e\n \u003cp\u003e15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 163px;\"\u003e\n \u003cp\u003e70% (10/15)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 166px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eTotal\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 155px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e-\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 69px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e35\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 163px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e85.7% (30/35)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 2.\u0026nbsp;\u003c/strong\u003eDemographic and Clinical Characteristics of Patient Groups Pre-protocol(N=86) and Per-protocol(N=97). *LOS Lenght of stay in Hospital, ** NIV Non invasive ventilation, ***VAM \u0026nbsp;Mechanical Ventilation\u0026nbsp;\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"597\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 152px;\"\u003e\n \u003cp\u003e\u003cstrong\u003ePre-protocol (N=86)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 152px;\"\u003e\n \u003cp\u003e\u003cstrong\u003ePer-protocol (N=97)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e\u003cstrong\u003ep-value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eAge (months)\u003c/strong\u003e, mean \u0026plusmn; SD\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 152px;\"\u003e\n \u003cp\u003e5.10 \u0026plusmn; 5.35\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 152px;\"\u003e\n \u003cp\u003e6.96 \u0026plusmn; 6.94\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026mdash;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eWeight (kg)\u003c/strong\u003e, mean \u0026plusmn; SD\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 152px;\"\u003e\n \u003cp\u003e6.09 \u0026plusmn; 2.41\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 152px;\"\u003e\n \u003cp\u003e7.05 \u0026plusmn; 3.04\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026mdash;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eSex (Male)\u003c/strong\u003e, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 152px;\"\u003e\n \u003cp\u003e49 (57.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 152px;\"\u003e\n \u003cp\u003e60 (61.9%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e0.603\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eLOS* (days)\u003c/strong\u003e, mean \u0026plusmn; SD\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 152px;\"\u003e\n \u003cp\u003e7.12 \u0026plusmn; 8.95\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 152px;\"\u003e\n \u003cp\u003e6.13 \u0026plusmn; 2.60\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e0.303\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003e\u003cstrong\u003ePICU Admission\u003c/strong\u003e, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 152px;\"\u003e\n \u003cp\u003e10 (11.6%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 152px;\"\u003e\n \u003cp\u003e20 (20.6%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e0.150\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eNIV**,\u0026nbsp;\u003c/strong\u003en (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 152px;\"\u003e\n \u003cp\u003e5 (5,8%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 152px;\"\u003e\n \u003cp\u003e18 (18.6%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.018\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eVAM**,\u0026nbsp;\u003c/strong\u003en(%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 152px;\"\u003e\n \u003cp\u003e5 (5.8%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 152px;\"\u003e\n \u003cp\u003e2 (2.1%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e0.350\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eViral Etiology (Overall)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 152px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 152px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.024\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003eTable 3.\u003c/strong\u003e Comparison of Clinical Respiratory Scores (CRS) Between Study Cohorts.\u003c/p\u003e\n\u003cp\u003eData are presented as Mean and Interquartile Range (IQR: 25th\u0026ndash;75th percentiles). The table compares the respiratory distress levels of the Pre-Protocol cohort (October 2017 \u0026ndash; February 2019) and the Per-Protocol cohort (2021\u0026ndash;2022) at baseline and subsequent time points. Statistical significance was set at p \u0026lt; 0.05.\u0026nbsp;\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"593\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 98px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eTime Point\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 98px;\"\u003e\n \u003cp\u003e\u003cstrong\u003ePre-Protocol Mean\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 99px;\"\u003e\n \u003cp\u003e\u003cstrong\u003ePre-Protocol IQR (Q1-Q3)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 98px;\"\u003e\n \u003cp\u003e\u003cstrong\u003ePer-Protocol Mean\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 99px;\"\u003e\n \u003cp\u003e\u003cstrong\u003ePer-Protocol IQR (Q1-Q3)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 101px;\"\u003e\n \u003cp\u003e\u003cstrong\u003ep-value (Mann-Whitney)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 98px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eBaseline (T0)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 98px;\"\u003e\n \u003cp\u003e2.35\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 99px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e1.00 - 3.00\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 98px;\"\u003e\n \u003cp\u003e4.57\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 99px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e4.00 - 5.00\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 101px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt; 0.0001\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 98px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e24 Ore\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 98px;\"\u003e\n \u003cp\u003e3.11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 99px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e2.00 - 4.00\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 98px;\"\u003e\n \u003cp\u003e2.96\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 99px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e2.00 - 4.00\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 101px;\"\u003e\n \u003cp\u003e0.5397\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 98px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e48 Ore\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 98px;\"\u003e\n \u003cp\u003e3.25\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 99px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e2.00 - 4.00\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 98px;\"\u003e\n \u003cp\u003e2.46\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 99px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e2.00 - 3.00\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 101px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.0008\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 98px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e72 Ore\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 98px;\"\u003e\n \u003cp\u003e3.05\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 99px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e2.00 - 4.00\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 98px;\"\u003e\n \u003cp\u003e1.91\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 99px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e1.00 - 3.00\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 101px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt; 0.0001\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"european-journal-of-pediatrics","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"ejpe","sideBox":"Learn more about [European Journal of Pediatrics](https://www.springer.com/journal/431)","snPcode":"431","submissionUrl":"https://submission.nature.com/new-submission/431/3","title":"European Journal of Pediatrics","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"bronchiolitis, oxygen therapy flowchart, high-flow nasal cannula, non-invasive ventilation, Clinical Respiratory Score, pediatric ward, pediatric intensive care unit","lastPublishedDoi":"10.21203/rs.3.rs-9159619/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9159619/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eBronchiolitis is the leading cause of non-elective hospitalizations in infants, with an increasing use of High-Flow Nasal Cannula (HFNC) therapy outside the Pediatric Intensive Care Unit (PICU). At our hospital, HFNC was used to treat pediatric bronchiolitis patients without a standardized protocol for initiation, flow titration, escalation, or a PICU alert system in cases of clinical deterioration.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eObjective and Study Design:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis quality improvement project aimed to evaluate the feasibility of a multidisciplinary protocol designed to standardize HFNC use for bronchiolitis in patients under 24 months of age, admitted to the Emergency Department (ED) during the 2021-2023 winter seasons and through the first 72 hours of hospitalization. The primary outcomes were healthcare provider adherence and staff satisfaction. The protocol utilized the Clinical Respiratory Score (CRS) to guide therapy: low-flow oxygen for CRS \u0026lt;4, HFNC with PICU notification for CRS 4–7, and consideration for Non-Invasive Ventilation (NIV) and PICU transfer for CRS \u0026gt;7. Satisfaction was assessed via a questionnaire stratified by clinical experience. As a secondary objective, CRS and clinical outcomes (length of stay [LOS] and PICU admission rates) of the per-protocol group were compared to a historical cohort admitted to our hospital during the two preceding winter seasons.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eProspective \u0026nbsp;data from 114 patients were analyzed; 97 were managed in full compliance with \u0026nbsp;the protocol, yielding an adherence rate of 85.1%. Staff satisfaction was 100% \u0026nbsp;among pediatric residents (n=5) and junior physicians (\u0026lt;5 years of \u0026nbsp;experience, n=15), while senior physicians (≥5 years of experience, n=15) \u0026nbsp;reported a 70% satisfaction rate. No significant differences were observed in \u0026nbsp;LOS (6.13 ± 2.60 days per-protocol vs. 7.12 ± 8.95 days pre-protocol; p=0.303) \u0026nbsp;or PICU admission rates (20.6% per-protocol vs. 11.6% pre-protocol; p=0.150). \u0026nbsp;In the retrospective cohort (n=86), the mean CRS at ED admission was \u0026nbsp;significantly lower than in the per-protocol group (p \u0026lt; 0.001). However, the per-protocol group exhibited \u0026nbsp;significantly lower CRS values at 48 and 72 hours (p \u0026lt; 0.001), despite \u0026nbsp;higher baseline severity.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusions:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe implementation of a structured HFNC protocol based on CRS scores is feasible in a tertiary pediatric setting, achieving high adherence (85%) and overall staff satisfaction (85.7%). While clinical outcomes remained comparable, the standardized approach encouraged early monitoring and was associated with earlier improvement in respiratory scores. Future initiatives should focus on optimizing adherence and addressing the specific concerns of senior clinical staff.\u003c/p\u003e","manuscriptTitle":"High Flow Nasal Cannula Therapy in Acute Bronchiolitis: an Italian Children’s Hospital Protocol","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-01 05:31:41","doi":"10.21203/rs.3.rs-9159619/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-04-03T20:21:47+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-03-29T15:04:05+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"104332300355945837500142725126609742428","date":"2026-03-27T10:13:44+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-03-27T10:02:11+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-03-27T09:37:05+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-03-27T02:50:32+00:00","index":"","fulltext":""},{"type":"submitted","content":"European Journal of Pediatrics","date":"2026-03-18T12:39:22+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"european-journal-of-pediatrics","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"ejpe","sideBox":"Learn more about [European Journal of Pediatrics](https://www.springer.com/journal/431)","snPcode":"431","submissionUrl":"https://submission.nature.com/new-submission/431/3","title":"European Journal of Pediatrics","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"b6e4e770-de3b-49b7-8953-6f3c4c40a6dd","owner":[],"postedDate":"April 1st, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-05-04T13:54:39+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-01 05:31:41","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9159619","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9159619","identity":"rs-9159619","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}