The Effect of High Lateral Position on Antibiotic Exposure Duration in Patients with Severe Traumatic Brain Injury: A Retrospective Observational Cohort Study

The Effect of High Lateral Position on Antibiotic Exposure Duration in Patients with Severe Traumatic Brain Injury: A Retrospective Observational Cohort Study | 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 Article The Effect of High Lateral Position on Antibiotic Exposure Duration in Patients with Severe Traumatic Brain Injury: A Retrospective Observational Cohort Study Zhongbao Lin, Dandan Chen, Mei Ye, Xincai Wang, Bin Shao, Long Huang This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6365655/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Patients with severe traumatic brain injury (sTBI) frequently require mechanical ventilation and develop aspiration pneumonia, leading to prolonged antibiotic use. This study evaluates whether High Lateral Position (HLP) reduces antibiotic exposure duration in sTBI patients. Data from 138 mechanically ventilated sTBI patients with aspiration pneumonia (January 2023–June 2024) were retrospectively analyzed. Patients were stratified into HLP (n = 45) and non-HLP (n = 93) groups. Linear regression models assessed associations between HLP and antibiotic exposure. HLP significantly reduced antibiotic duration (β=−2.58; 95% CI: −4.44 to − 0.71; P = 0.008) and mechanical ventilation days (7.0 vs. 9.0, P = 0.004). Chronic obstructive pulmonary disease (COPD) increased antibiotic exposure (β = 8.78; 95% CI: 4.42–13.13; P < 0.001). HLP also lowered tracheostomy rates (6.7% vs. 20.4%, P = 0.038). These findings suggest HLP optimizes secretion drainage and reduces pulmonary complications, offering a cost-effective strategy to mitigate antibiotic resistance. Health sciences/Medical research Health sciences/Neurology Severe traumatic brain injury High lateral position Antibiotic exposure time Aspiration pneumonia Figures Figure 1 Figure 2 Figure 4 Background Severe Traumatic Brain Injury (sTBI) is a type of brain tissue damage caused by mechanical external force. It affects over 50 million people worldwide each year, resulting in significant mortality, disability, and socioeconomic burden. Epidemiological data indicate that in some countries, the mortality rate related to Traumatic Brain Injury (TBI) is approximately 13 per 100,000 population, consistent with levels reported in other regions 1 , 2 . Patients with sTBI often experience weakened cough reflex, retained secretions, and increased risk of aspiration due to dysfunction of the respiratory center. These factors can lead to complications such as atelectasis and pneumonia, with around 60% of patients requiring mechanical ventilation 3 , 4 . Secondary pulmonary infections can increase the mortality rate of patients by 3 to 5 times, highlighting the importance of early intervention 5 . Optimizing respiratory management is a crucial component in improving the prognosis of severe traumatic brain injury (sTBI). Studies have shown that enhanced airway care can shorten the duration of antibiotic therapy, reduce the risk of multidrug-resistant infections, and decrease the failure rate of endotracheal intubation by 20–40% 6,7 . Among these interventions, positioning management plays an important role by regulating the ventilation/perfusion ratio and facilitating the drainage of secretions 8 . Although prone positioning (PP) can improve the clearance of pulmonary secretions 9 , 10 , its impact on intracranial pressure remains controversial: Thelandersson et al 11 reported that PP does not alter intracranial pressure, while Roth et al 12 found that it can increase intracranial pressure by 15–30%. Additionally, PP may increase the risk of pressure ulcers and interfere with pupil monitoring 13 – 15 , which significantly limits its application in sTBI. The High Lateral Position (HLP) has emerged as a potential alternative due to its ease of operation and low incidence of complications. Siswanto et al 16 confirmed that HLP is comparable to prone positioning (PP) in improving oxygenation and can effectively reduce the incidence of ventilator-associated pneumonia. However, the impact of HLP on antibiotic exposure duration, pulmonary function improvement, and sputum drainage efficiency in patients with severe traumatic brain injury (sTBI) remains unclear, and its clinical value urgently needs systematic evaluation. This study, through a retrospective cohort analysis, is the first to explore the impact of HLP on the duration of antibiotic therapy, airway management efficacy, and prognosis in sTBI patients, aiming to provide evidence-based support for optimizing positional therapy strategies in neurocritical care. Methods Study Design and Participants This retrospective cohort study was conducted in the intensive care units of the aforementioned hospitals from January 2023 to June 2024. All methods were performed in accordance with the relevant guidelines and regulations, including the Declaration of Helsinki. The study protocol was approved by the Institutional Ethics Committee of Shengli Clinical Medical College of Fujian Medical University (Approval Code: K2022-09-061). Data were extracted retrospectively from the clinical information system database of the participating hospitals. Due to the non-interventional, observational nature of this study and the absence of any physiological risks to patients, the ethics committee waived the requirement for informed consent. All patient data were anonymized and processed in strict compliance with institutional privacy protection protocols. All patients enrolled in this study met the following criteria: (1) Glasgow Coma Scale (GCS) score ≤ 8; (2) radiologically confirmed aspiration pneumonia; (3) age between 18 and 80 years; (4) ICU stay of at least 7 days; (5) invasive mechanical ventilation initiated after admission to the department. Exclusion criteria included: (1) presence of active bleeding, spinal injury, or patients in the late stage of pregnancy; (2) combined with hemopneumothorax or severe arrhythmia; (3) patients who died or were discharged against medical advice within 7 days of admission.Based on the diagnostic criteria for TBI, an initial total of 863 TBI patients were identified. According to the inclusion and exclusion criteria, 206 patients with severe traumatic brain injury (sTBI) who had a GCS score ≤ 8 and received mechanical ventilation immediately upon admission were selected. Among these 206 sTBI patients, 28 patients had mechanical ventilation discontinued within 2 hours after admission. Based on chest X-ray or chest CT findings, 40 patients were diagnosed with uncomplicated pneumonia and were excluded from the study. After screening, 138 eligible patients with severe TBI complicated by aspiration pneumonia were included in the final analysis (see Fig. 1 ).This study primarily investigates the impact of High Lateral Position (HLP) on antibiotic exposure time, with HLP as the independent variable and antibiotic exposure time as the dependent variable. The screening results showed that among the final included patients, approximately 67.4% (93/138) did not receive HLP intervention, while 32.6% (45/138) received HLP intervention. Through strict screening, patient homogeneity was ensured, and confounding factors were minimized. This provided a solid basis for analyzing the effectiveness of HLP intervention and enhanced the reliability of the assessment of the HLP intervention effect. Intervention Implementation Criteria for High Lateral Position (HLP) In this study, the implementation of High Lateral Position (HLP) followed a standardized protocol. First, contraindications such as spinal injury, active bleeding, and severe arrhythmia were excluded, and the patency of all catheters and the use of a pressure-relief mattress were confirmed 17 . When implementing HLP, two well-trained medical staff members would turn the patient from a supine position to a 90°±5° lateral position (confirmed using a standard angle measuring device), with each position maintained for at least 60 minutes, and the direction of lateral positioning alternated every 2 hours. Soft pillows were used to secure the position, ensuring that the lower arm was perpendicular to the trunk and the upper limb was flexed and supported by soft pillows to distribute pressure. Vital signs, skin condition, and respiratory parameters were regularly monitored before, during, and after the implementation, with clear cessation criteria set: (1) intracranial pressure exceeding 25 mmHg for more than 5 minutes; (2) a decrease in mean arterial pressure of > 20%; (3) persistent hypoxemia or new-onset arrhythmia. The entire procedure ensured spinal stability and avoided traction on the catheters. For a detailed illustration of the procedure, see Fig. 2 . Selection of Covariates To control for the potential impact of confounding factors on the association between High Lateral Position (HLP) and antibiotic exposure time, this study systematically included four categories of covariates: (1) Baseline characteristics: including gender, age, and underlying diseases (hypertension, diabetes, COPD, CKD, CHD); (2) Physiological indicators: GCS score, APACHE-II score, SOFA score, mean arterial pressure (MAP), and the use of vasopressors; (3) Laboratory parameters: arterial blood gas, inflammatory markers, and related biochemical indicators on the first and seventh days of admission; (4) Sedation depth: Richmond Agitation–Sedation Scale (RASS) score. The primary outcome measure of this study, "antibiotic exposure time," was defined as the continuous number of days from the first administration of antibiotics to the final discontinuation. The criteria for discontinuation included18,19: (a) Clinical symptom improvement: body temperature < 38°C for 24 hours; (b) Laboratory parameter improvement: procalcitonin (PCT) levels dropping to 80% of the baseline value or < 0.5 ng/mL, and normalization of white blood cell count; (c) Radiological improvement: significant improvement in pulmonary infection signs on chest X-ray or CT. The calculation method was the end date minus the start date plus 1 day, with antibiotic changes without an interruption period considered as continuous use. All patients received a standardized critical care management protocol, which included neurosurgical interventions, dehydration to reduce intracranial pressure, anti-infective treatment, prevention of complications, and nutritional support. Sedation and analgesia were achieved through continuous intravenous infusion of midazolam combined with sufentanil, targeting a RASS score of -2 to 0, and core body temperature was controlled at 36–37°C through physical cooling methods. Nursing interventions included continuous monitoring of vital signs, airway humidification management, and positional adjustments every 2 hours combined with back tapping to facilitate sputum drainage. The non-HLP group received conventional supine mechanical ventilation, while the HLP group was positioned in a 90° high lateral position. All other therapeutic measures were kept consistent between the two groups to clarify the independent effect of positional intervention. Statistical Analysis The data were presented as follows: Normally distributed continuous variables were expressed as mean (standard deviation), non-normally distributed continuous variables as median (interquartile range [IQR]), and categorical variables as frequency (percentage). For comparisons between groups, continuous variables were analyzed using Student’s t-test or Mann–Whitney U test depending on their distribution characteristics, while categorical variables were compared using Fisher’s exact test. Linear regression models (β coefficients) and 95% confidence intervals (CI) were used to assess the impact of High Lateral Position (HLP) on antibiotic exposure time, with adjustments made for major covariates. A p-value of less than 0.05 was considered statistically significant. All statistical analyses were performed using R software package version 3.3.2 ( , The R Foundation) and Free Statistics software version 1.9.2. Results Clinical Characteristics and Treatment Outcomes of the Study Population A total of 138 patients with severe traumatic brain injury (sTBI) were ultimately included in this study. Among them, 82.6% (114/138) were male, and 17.4% (24/138) were female, with a mean age of 56.8±16.5 years. The main comorbidities included: epidural hematoma (51.4%), basal skull fracture (50.7%), subdural hematoma (38.4%), skull fracture (34.1%), and subarachnoid hemorrhage (21.7%). The distribution of comorbidity combinations is detailed in Figure 3. The baseline characteristics were well-balanced between groups (see Table 1). There was no significant difference in age between the HLP group (n=45) and the supine group (n=93) (59.7±15.5 vs. 55.4±16.8, P=0.15). On day 7 of treatment, the HLP group had significantly lower levels of PaCO₂, PCT, WBC, days of mechanical ventilation, duration of antibiotic exposure, and tracheostomy rate compared to the supine group, with all p-values <0.05, indicating statistically significant differences (see Table 1 and Figure 4). Factors Influencing Antibiotic Exposure in Severe Traumatic Brain Injury Univariate analysis results indicated that protective factors such as HLP (β= -2.93; 95% CI, -4.9 to -0.96; P=0.004), PaO₂ on day 1 (β= -0.02; 95% CI, -0.04 to 0; P=0.039), PaO₂ on day 7 (β= -0.02; 95% CI, -0.04 to 0; P=0.018), and P/F ratio (β= -0.01; 95% CI, -0.02 to 0; P=0.011) can reduce antibiotic exposure time in patients with severe traumatic brain injury (sTBI). Conversely, risk factors such as COPD (β= 9.72; 95% CI, 5.71 to 13.74; P<0.001) and days of mechanical ventilation (β=1.03; 95% CI, 0.92 to 1.14; P<0.001) can increase antibiotic exposure time in sTBI patients. (See Table 2) Multivariate Regression Models Showed: Model I (Without Adjusting for Any Covariates): HLP (β= -2.93; 95% CI, -4.9 to -0.96; P=0.004), PaO₂ on day 1 (β= -0.21; 95% CI, -0.41 to -0.01; P=0.039), and P/F ratio on day 7 (β= -0.12; 95% CI, -0.21 to -0.03; P=0.011) were independent protective factors. COPD (β= 9.72; 95% CI, 5.71 to 13.74; P<0.001) was a significant risk factor. Model II (Adjusted for Age and Gender): HLP (β= -3.17; 95% CI, -5.13 to -1.22; P=0.002) and P/F ratio on day 7 (β= -0.11; 95% CI, -0.2 to -0.01; P=0.027) remained protective factors. COPD (β= 9.69; 95% CI, 5.43 to 13.94; P<0.001) remained a significant risk factor. Model III (Further Adjusted for Age, Gender, COPD, PaO₂ on Day 1, and P/F on Day 7): HLP (β= -2.58; 95% CI, -4.44 to -0.71; P=0.008) remained a protective factor for antibiotic exposure time in sTBI patients. COPD (β= 8.78; 95% CI, 4.42 to 13.13; P<0.001) remained a significant risk factor for antibiotic exposure time in sTBI patients. (See Table 3) Discussion This study, through a retrospective cohort analysis, has for the first time confirmed that High Lateral Position (HLP) can significantly reduce the duration of antibiotic exposure in patients with severe traumatic brain injury (sTBI) complicated by aspiration pneumonia by 2.9 days (P = 0.008). It also decreases the duration of mechanical ventilation (7.0 vs. 9.0 days) and the rate of tracheostomy (6.7% vs. 20.4%). Considering that the average daily cost of antibiotics in the ICU of this country is approximately 500–800 units of the national currency per day 20 , it is estimated that each patient can save medical costs of 1450–2320 units of the national currency. Compared with prone positioning (PP), HLP has greater advantages in maintaining intracranial pressure (ICP) stability 21 , 22 ,and does not affect neurological monitoring, with convenient pupil assessment. This finding provides important evidence-based support for optimizing the positional management of sTBI patients and reveals the potential value of HLP in reducing the risk of multidrug resistance and medical costs. It is worth noting that although the 28-day mortality rate in the HLP group was lower than that in the supine group (8.9% vs. 18.3%), the difference did not reach statistical significance (P = 0.15). This may be related to the following factors: (1) The limited sample size of this study (n = 45 in the HLP group) led to insufficient statistical power; (2) Mortality is influenced by multiple factors, such as the initial GCS score and secondary brain injury events. Additionally, this study did not include subgroup analyses based on injury severity; (3) The 28-day observation window may not be sufficient to capture the long-term survival benefits of positional interventions.The Guidelines for the Management of Severe Traumatic Brain Injury 23 indicate that the 90-day mortality rate in sTBI patients is significantly associated with early respiratory management strategies, suggesting that future studies should extend the follow-up period. Moreover, the potential impact of HLP on the function of organs other than the lungs, such as the intestinal barrier and immune regulation, remains unclear. This uncertainty may limit the extent to which HLP can improve overall prognosis. Patients with sTBI are prone to weakened ciliary movement in the airways, suppressed cough reflex, and retained secretions due to the inhibition of the respiratory center, the use of sedatives, and mechanical ventilation. This leads to the accumulation of large amounts of viscous secretions in the deep bronchi 24 . This accumulation creates a vicious cycle of “infection–inflammation–reinfection,” which further delays recovery and prolongs ICU stays. It also increases the risk of long-term sequelae, physical, psychological, and psychiatric complications, as well as cognitive impairments 25 . HLP breaks this cycle through its anatomical advantages. When patients are positioned in HLP, the bronchial openings of the upper lung are oriented downward, allowing airway secretions to drain into the larger airways under the influence of gravity. This reduces the accumulation of secretions caused by gravity, prevents pulmonary edema and sputum retention, and decreases the risk of infection 26 , 27 . In this study, the HLP group had a significant reduction in PaCO₂ on day 7 (P < 0.05), indicating improved efficiency of secretion clearance, which is consistent with the study by Wang QY et al 28 . Additionally, the high lateral position increases the expansion of the thoracic cage, enhances the coordinated action of the abdominal and diaphragmatic muscles, and improves peak expiratory flow (PEF), thereby facilitating sputum expulsion and reducing the risk of infection due to pulmonary insufficiency 29 . Moreover, when in the HLP position, pulmonary blood flow to the gravity-dependent areas increases by approximately 25% compared to the supine position. This provides better support for blood flow to the lung bases, while ventilation in the non-gravity-dependent alveoli is more adequate. This physiological effect reduces local hypoxia and atelectasis and lowers the risk of infection caused by immune suppression 30 . It is worth noting that patients with comorbid COPD had the highest risk of prolonged antibiotic exposure (β = 8.78, P < 0.001). This may be related to the pathological characteristics of COPD—chronic airway inflammation, progressive airflow limitation, and excessive mucus secretion, which lead to secondary infections, worsening airway inflammation, and a vicious cycle of mucus hypersecretion and inflammation that reduces lung function 31 . Patients with frequent acute exacerbations of COPD are more prone to multidrug-resistant infections 32 .HLP may interrupt this process by facilitating early extubation (a reduction of 2 days in mechanical ventilation) and lowering inflammatory markers (PCT↓0.3 ng/mL, WBC↓2.0×10⁹/L). This is consistent with the argument proposed by Kong L et al 33 that HLP can allow for more effective drainage of airway secretions, enhance the anti-inflammatory effects of antibiotics, effectively control pulmonary infections, shorten the window for controlling pulmonary infections, and better advance the implementation of invasive-to-non-invasive sequential weaning protocols. It also complements the “short-course antibiotic strategy” proposed by Kubo K et al 34 , providing a non-pharmacological intervention pathway for the prevention and control of multidrug resistance in patients with traumatic brain injury. The Neurocritical Care Society (NCS) 2023 guidelines recommend a head-elevated position of 15–30° for patients with sTBI to balance intracranial pressure (ICP) and lung protection 35 , but they do not specify the angle for lateral positioning. This study provides direct evidence for the safety and efficacy of a 90° high lateral position (HLP). It is suggested that future guidelines consider incorporating HLP as an option for positional management in patients with sTBI. However, this study has certain limitations. First, it is a retrospective analysis of treatment data from past patients. Although multivariate adjustments were made, unrecorded confounding factors such as sputum viscosity and suctioning frequency may have influenced the results. Although we statistically corrected for bias, we cannot rule out other unmeasured or uncollected confounding factors that may affect treatment outcomes. For example, respiratory mechanics such as transpulmonary pressure and airway resistance were not recorded during treatment, nor were long-term neurological function data such as the 90-day Glasgow Outcome Scale (GOS) score. We were also unable to further explore the impact on airway resistance and lung ventilation. Additionally, the effects of interventions such as percussion and vibration therapy and fiberoptic bronchoscopy on airway secretion drainage were not considered. These factors could all influence the final observed outcomes. The single-center sample of 138 patients may limit statistical power, and extrapolating the results to non-sTBI patients should be done with caution. Future research should conduct multicenter randomized controlled trials (RCTs) and include the following improvements: (1) Using electrical impedance tomography (EIT) to dynamically monitor lung ventilation distribution; (2) Combining microbiome analysis to study the evolution of antibiotic resistance spectra; (3) Developing a standardized operating procedure (SOP) for HLP, including position angle (90°±5°), turning frequency, and pressure ulcer risk stratification monitoring. By integrating multidimensional assessments of mechanical ventilation, infection management, and health economics, the translation of HLP from evidence-based medicine to clinical practice can be further advanced. Conclusions The results of this retrospective observational study indicate that the High Lateral Position (HLP) is associated with a reduction in antibiotic exposure time in patients with severe traumatic brain injury. The data show that patients receiving HLP had an average reduction of approximately 2.9 days in antibiotic use compared to those in the conventional supine position, with a trend towards fewer days of mechanical ventilation and a lower rate of tracheostomy. These associations may be achieved through mechanisms such as improved secretion drainage, optimized ventilation/perfusion ratio, and reduced risk of aspiration. Abbreviations HLP High Lateral Position COPD chronic pulmonary disease sTBI Severe Traumatic Brain Injury TBI Traumatic Brain Injury PP prone positioning APACHE II Acute Physiology and Chronic Health Evaluation II score GCS Glasgow coma scale ICU intensive care unit PCT procalcitonin SOFA Sequential Organ Failure Assessment MAP mean arterial pressure RASS Richmond Agitation-Sedation Scale P/F PaO2/FiO2 WBC white blood count HBP hypertension or high Blood pressure DM diabetes mellitus CKD chronic kidney disease CHD coronary heart disease CI confidence intervals IQR interquartile range PEF Peak Expiratory Flow SOP Standard Operating Procedure Declarations Acknowledgements The authors thank Fujian Provincial Hospital’s intensive care units staff for their support and guidance in performing this study. Additionally, we obliged thank the Free Statistics team (Beijing, China) for providing technical assistance and practical data analysis and visualization tools. Funding This work was supported by the Scientific Foundation of Fujian Health Department (Grant No.2020QNB006 ), the Startup Fund for scientific research, Fujian Medical University (Grant No.2020QH1139 and 2021QH1285). Author information Authors and Affiliations Zhongbao Lin1#, RN, Dandan Chen2#,RN, Mei Ye1, RN, Xincai Wang1, MD, Bin Shao3*,MD,Long Huang1*,MD. 1 Fujian Provincial Hospital Affiliated to Fuzhou University, Shengli Clinical Medical College of Fujian Medical University, Department of Critical Care Medicine, Fuzhou 350001, P. R. China. 2 Fujian Provincial Hospital Affiliated to Fuzhou University, Shengli Clinical Medical College of Fujian Medical University, Department of Respiratory and Critical Care Medicine, Fuzhou 350001, P. R. China. 3 Fujian Provincial Hospital Affiliated to Fuzhou University, Shengli Clinical Medical College of Fujian Medical University , Department of Rehabilitation, Fuzhou 350001, P. R. China. Contributions Long Huang and Bin Shao participated in study design, supervised data analysis, and revised the manuscript. Zhongbao Lin and Dandan Chen contributed equally to data collection, clinical intervention implementation, and preliminary statistical analysis. Mei Ye participated in patient management, nursing care, and clinical data organization. Xincai Wang performed radiological assessments (e.g., chest CT/X-ray interpretation) and critical care protocol design. Bin Shao provided expertise in rehabilitation strategies and long-term complication prevention. Long Huang conducted multivariate regression modeling and statistical validation using R/Free Statistics software. Zhongbao Lin and Dandan Chen collaborated on drafting the methods and results sections. All authors participated in manuscript proofreading and approved the final version.Long Huang and Xincai Wang acquired financial support from the Scientific Foundation of Fujian Health Department (Grant No.2020QNB006) and Fujian Medical University (Grants No.2020QH1139, 2021QH1285). Corresponding authors Correspondence to Bin Shao or Long Huang. Ethics Approval The studies involving human participants were reviewed and approved by the IRB of Shengli Clinical Medical College of Fujian Medical University with the ethical approval number K2022-09- 061. Written informed consent for participation was not required for this study in accordance with the national legislation and the institutional requirements. Consent for publication All authors have reviewed the manuscript and approved its submission for publication. Competing interests The authors declare that they have no competing interests. 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Care Med. 208 , 1026–1041 (2023). Kong, L. et al. [Effect of lateral position ventilation combined with vibration sputum drainage on patients with acute respiratory distress syndrome: a prospective randomized controlled trial]. Zhonghua Wei Zhong Bing Ji Jiu Yi Xue . 30 , 240–245 (2018). Kubo, K., Kondo, Y., Yoshimura, J., Kikutani, K. & Shime, N. Short- versus prolonged-course antibiotic therapy for sepsis or infectious diseases in critically ill adults: a systematic review and meta-analysis. Infect. Dis. (Lond) . 54 , 213–223 (2022). Lulla, A. et al. Prehospital Guidelines for the Management of Traumatic Brain Injury – 3rd Edition. Prehosp Emerg. Care . 27 , 507–538 (2023). Tables Tables 1 to 3 are available in the Supplementary Files section. Additional Declarations No competing interests reported. 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Chen","email":"","orcid":"","institution":"Fujian Provincial Hospital Affiliated to Fuzhou University, Shengli Clinical Medical College of Fujian Medical University","correspondingAuthor":false,"prefix":"","firstName":"Dandan","middleName":"","lastName":"Chen","suffix":""},{"id":451945165,"identity":"1bb67913-9d73-4ff9-bd3a-cf7163aec046","order_by":2,"name":"Mei Ye","email":"","orcid":"","institution":"Fujian Provincial Hospital Affiliated to Fuzhou University, Shengli Clinical Medical College of Fujian Medical University","correspondingAuthor":false,"prefix":"","firstName":"Mei","middleName":"","lastName":"Ye","suffix":""},{"id":451945166,"identity":"17927b21-580e-409c-a3f1-80d1dfb60509","order_by":3,"name":"Xincai Wang","email":"","orcid":"","institution":"Fujian Provincial Hospital Affiliated to Fuzhou University, Shengli Clinical Medical College of Fujian Medical University","correspondingAuthor":false,"prefix":"","firstName":"Xincai","middleName":"","lastName":"Wang","suffix":""},{"id":451945167,"identity":"58e011ad-226e-453e-8b42-4199867ea26c","order_by":4,"name":"Bin Shao","email":"","orcid":"","institution":"Fujian Provincial Hospital Affiliated to Fuzhou University, Shengli Clinical Medical College of Fujian Medical University","correspondingAuthor":false,"prefix":"","firstName":"Bin","middleName":"","lastName":"Shao","suffix":""},{"id":451945168,"identity":"4fa1fa6d-2ac9-4377-952a-a80f1cc7443b","order_by":5,"name":"Long Huang","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABE0lEQVRIiWNgGAWjYBACAzBZAMTMzAcffKiQYwYL8BDUAiLZ2ZINZ5wxJkULP4+ZNG+bMQNBLeYSyc8efjGwyZN35jE2nDnPgF13RgLjg7dtDPLmOLRYzkgzN5YxSCs2PMxW+ODjNgNmsxsJzIZz2xgMdzbgcNiNBDNpCYPDiRubmTcbztz2B6SFDehChgSDA7i0pH+DamEA+mUO2Bb23/i15JhJfgBqmc/MAtTSANbCxoxXy5k3ZdIMBmmJG5hBgXwMqOXMw2bJOeckDDfg0nI8fZvkjwqbxPn9h4FRWWOQbHY8+eCHN2U28rhsAQFmUCzAFCQzMDA2AGkJ3OqBgPEHkJBvgHDs8CodBaNgFIyCEQkAO7ZblN3JCYUAAAAASUVORK5CYII=","orcid":"","institution":"Fujian Provincial Hospital Affiliated to Fuzhou University, Shengli Clinical Medical College of Fujian Medical University","correspondingAuthor":true,"prefix":"","firstName":"Long","middleName":"","lastName":"Huang","suffix":""}],"badges":[],"createdAt":"2025-04-03 04:08:12","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6365655/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6365655/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":82351948,"identity":"e1106708-cf6b-4e1e-839d-bb10c64b30a9","added_by":"auto","created_at":"2025-05-09 11:00:11","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":216301,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eFlowchart of patient selection.\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"Figure1Flowchartofpatientselection..png","url":"https://assets-eu.researchsquare.com/files/rs-6365655/v1/f82c1e85d7c5202d62388759.png"},{"id":82351947,"identity":"82f6dcb8-eba2-4bdb-ad9f-2525d893638d","added_by":"auto","created_at":"2025-05-09 11:00:11","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":1086960,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eDiagram of High Lateral Position\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"Figure2DiagramofHighLateralPosition.png","url":"https://assets-eu.researchsquare.com/files/rs-6365655/v1/d193efb0a49dfdfb1d387642.png"},{"id":82351941,"identity":"e2f9d927-615e-4191-8c87-367923d9c22c","added_by":"auto","created_at":"2025-05-09 11:00:11","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":186087,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eComparison of antibiotic exposure time between groups.\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"Figure4Vio.Box.single.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6365655/v1/9a62f3cbf222892697d6ed18.jpg"},{"id":86690329,"identity":"0c5e5bc1-cdf8-40e0-9961-70ee7f3791fc","added_by":"auto","created_at":"2025-07-14 14:31:44","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1930829,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6365655/v1/e2f6139c-e031-4bdb-be2c-6986b00ad885.pdf"},{"id":82353495,"identity":"7fb76a74-b72f-46e6-b2b3-fb23882b01c4","added_by":"auto","created_at":"2025-05-09 11:08:11","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":29617,"visible":true,"origin":"","legend":"","description":"","filename":"statisticaltable.docx","url":"https://assets-eu.researchsquare.com/files/rs-6365655/v1/d80e8ee0adda5842252df4fd.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"The Effect of High Lateral Position on Antibiotic Exposure Duration in Patients with Severe Traumatic Brain Injury: A Retrospective Observational Cohort Study","fulltext":[{"header":"Background","content":"\u003cp\u003eSevere Traumatic Brain Injury (sTBI) is a type of brain tissue damage caused by mechanical external force. It affects over 50\u0026nbsp;million people worldwide each year, resulting in significant mortality, disability, and socioeconomic burden. Epidemiological data indicate that in some countries, the mortality rate related to Traumatic Brain Injury (TBI) is approximately 13 per 100,000 population, consistent with levels reported in other regions\u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e,\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e. Patients with sTBI often experience weakened cough reflex, retained secretions, and increased risk of aspiration due to dysfunction of the respiratory center. These factors can lead to complications such as atelectasis and pneumonia, with around 60% of patients requiring mechanical ventilation\u003csup\u003e\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e,\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u003c/sup\u003e. Secondary pulmonary infections can increase the mortality rate of patients by 3 to 5 times, highlighting the importance of early intervention\u003csup\u003e\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eOptimizing respiratory management is a crucial component in improving the prognosis of severe traumatic brain injury (sTBI). Studies have shown that enhanced airway care can shorten the duration of antibiotic therapy, reduce the risk of multidrug-resistant infections, and decrease the failure rate of endotracheal intubation by 20\u0026ndash;40%\u003csup\u003e6,7\u003c/sup\u003e. Among these interventions, positioning management plays an important role by regulating the ventilation/perfusion ratio and facilitating the drainage of secretions\u003csup\u003e\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u003c/sup\u003e. Although prone positioning (PP) can improve the clearance of pulmonary secretions\u003csup\u003e\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e,\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u003c/sup\u003e, its impact on intracranial pressure remains controversial: Thelandersson et al\u003csup\u003e\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/sup\u003e reported that PP does not alter intracranial pressure, while Roth et al\u003csup\u003e\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u003c/sup\u003e found that it can increase intracranial pressure by 15\u0026ndash;30%. Additionally, PP may increase the risk of pressure ulcers and interfere with pupil monitoring\u003csup\u003e\u003cspan additionalcitationids=\"CR14\" citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e\u003c/sup\u003e, which significantly limits its application in sTBI.\u003c/p\u003e \u003cp\u003eThe High Lateral Position (HLP) has emerged as a potential alternative due to its ease of operation and low incidence of complications. Siswanto et al\u003csup\u003e\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u003c/sup\u003e confirmed that HLP is comparable to prone positioning (PP) in improving oxygenation and can effectively reduce the incidence of ventilator-associated pneumonia. However, the impact of HLP on antibiotic exposure duration, pulmonary function improvement, and sputum drainage efficiency in patients with severe traumatic brain injury (sTBI) remains unclear, and its clinical value urgently needs systematic evaluation.\u003c/p\u003e \u003cp\u003eThis study, through a retrospective cohort analysis, is the first to explore the impact of HLP on the duration of antibiotic therapy, airway management efficacy, and prognosis in sTBI patients, aiming to provide evidence-based support for optimizing positional therapy strategies in neurocritical care.\u003c/p\u003e"},{"header":"Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStudy Design and Participants\u003c/h2\u003e \u003cp\u003e This retrospective cohort study was conducted in the intensive care units of the aforementioned hospitals from January 2023 to June 2024. All methods were performed in accordance with the relevant guidelines and regulations, including the Declaration of Helsinki. The study protocol was approved by the Institutional Ethics Committee of Shengli Clinical Medical College of Fujian Medical University (Approval Code: K2022-09-061). Data were extracted retrospectively from the clinical information system database of the participating hospitals. Due to the non-interventional, observational nature of this study and the absence of any physiological risks to patients, the ethics committee waived the requirement for informed consent. All patient data were anonymized and processed in strict compliance with institutional privacy protection protocols.\u003c/p\u003e \u003cp\u003eAll patients enrolled in this study met the following criteria: (1) Glasgow Coma Scale (GCS) score\u0026thinsp;\u0026le;\u0026thinsp;8; (2) radiologically confirmed aspiration pneumonia; (3) age between 18 and 80 years; (4) ICU stay of at least 7 days; (5) invasive mechanical ventilation initiated after admission to the department. Exclusion criteria included: (1) presence of active bleeding, spinal injury, or patients in the late stage of pregnancy; (2) combined with hemopneumothorax or severe arrhythmia; (3) patients who died or were discharged against medical advice within 7 days of admission.Based on the diagnostic criteria for TBI, an initial total of 863 TBI patients were identified. According to the inclusion and exclusion criteria, 206 patients with severe traumatic brain injury (sTBI) who had a GCS score\u0026thinsp;\u0026le;\u0026thinsp;8 and received mechanical ventilation immediately upon admission were selected. Among these 206 sTBI patients, 28 patients had mechanical ventilation discontinued within 2 hours after admission. Based on chest X-ray or chest CT findings, 40 patients were diagnosed with uncomplicated pneumonia and were excluded from the study. After screening, 138 eligible patients with severe TBI complicated by aspiration pneumonia were included in the final analysis (see Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).This study primarily investigates the impact of High Lateral Position (HLP) on antibiotic exposure time, with HLP as the independent variable and antibiotic exposure time as the dependent variable. The screening results showed that among the final included patients, approximately 67.4% (93/138) did not receive HLP intervention, while 32.6% (45/138) received HLP intervention. Through strict screening, patient homogeneity was ensured, and confounding factors were minimized. This provided a solid basis for analyzing the effectiveness of HLP intervention and enhanced the reliability of the assessment of the HLP intervention effect.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eIntervention\u003c/h3\u003e\n\u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eImplementation Criteria for High Lateral Position (HLP)\u003c/h2\u003e \u003cp\u003eIn this study, the implementation of High Lateral Position (HLP) followed a standardized protocol. First, contraindications such as spinal injury, active bleeding, and severe arrhythmia were excluded, and the patency of all catheters and the use of a pressure-relief mattress were confirmed\u003csup\u003e\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e\u003c/sup\u003e. When implementing HLP, two well-trained medical staff members would turn the patient from a supine position to a 90\u0026deg;\u0026plusmn;5\u0026deg; lateral position (confirmed using a standard angle measuring device), with each position maintained for at least 60 minutes, and the direction of lateral positioning alternated every 2 hours. Soft pillows were used to secure the position, ensuring that the lower arm was perpendicular to the trunk and the upper limb was flexed and supported by soft pillows to distribute pressure. Vital signs, skin condition, and respiratory parameters were regularly monitored before, during, and after the implementation, with clear cessation criteria set: (1) intracranial pressure exceeding 25 mmHg for more than 5 minutes; (2) a decrease in mean arterial pressure of \u0026gt;\u0026thinsp;20%; (3) persistent hypoxemia or new-onset arrhythmia. The entire procedure ensured spinal stability and avoided traction on the catheters. For a detailed illustration of the procedure, see Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eSelection of Covariates\u003c/h3\u003e\n\u003cp\u003eTo control for the potential impact of confounding factors on the association between High Lateral Position (HLP) and antibiotic exposure time, this study systematically included four categories of covariates: (1) Baseline characteristics: including gender, age, and underlying diseases (hypertension, diabetes, COPD, CKD, CHD); (2) Physiological indicators: GCS score, APACHE-II score, SOFA score, mean arterial pressure (MAP), and the use of vasopressors; (3) Laboratory parameters: arterial blood gas, inflammatory markers, and related biochemical indicators on the first and seventh days of admission; (4) Sedation depth: Richmond Agitation\u0026ndash;Sedation Scale (RASS) score.\u003c/p\u003e \u003cp\u003eThe primary outcome measure of this study, \"antibiotic exposure time,\" was defined as the continuous number of days from the first administration of antibiotics to the final discontinuation. The criteria for discontinuation included18,19: (a) Clinical symptom improvement: body temperature\u0026thinsp;\u0026lt;\u0026thinsp;38\u0026deg;C for 24 hours; (b) Laboratory parameter improvement: procalcitonin (PCT) levels dropping to 80% of the baseline value or \u0026lt;\u0026thinsp;0.5 ng/mL, and normalization of white blood cell count; (c) Radiological improvement: significant improvement in pulmonary infection signs on chest X-ray or CT. The calculation method was the end date minus the start date plus 1 day, with antibiotic changes without an interruption period considered as continuous use.\u003c/p\u003e \u003cp\u003eAll patients received a standardized critical care management protocol, which included neurosurgical interventions, dehydration to reduce intracranial pressure, anti-infective treatment, prevention of complications, and nutritional support. Sedation and analgesia were achieved through continuous intravenous infusion of midazolam combined with sufentanil, targeting a RASS score of -2 to 0, and core body temperature was controlled at 36\u0026ndash;37\u0026deg;C through physical cooling methods. Nursing interventions included continuous monitoring of vital signs, airway humidification management, and positional adjustments every 2 hours combined with back tapping to facilitate sputum drainage. The non-HLP group received conventional supine mechanical ventilation, while the HLP group was positioned in a 90\u0026deg; high lateral position. All other therapeutic measures were kept consistent between the two groups to clarify the independent effect of positional intervention.\u003c/p\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003eStatistical Analysis\u003c/h2\u003e \u003cp\u003eThe data were presented as follows: Normally distributed continuous variables were expressed as mean (standard deviation), non-normally distributed continuous variables as median (interquartile range [IQR]), and categorical variables as frequency (percentage). For comparisons between groups, continuous variables were analyzed using Student\u0026rsquo;s t-test or Mann\u0026ndash;Whitney U test depending on their distribution characteristics, while categorical variables were compared using Fisher\u0026rsquo;s exact test. Linear regression models (β coefficients) and 95% confidence intervals (CI) were used to assess the impact of High Lateral Position (HLP) on antibiotic exposure time, with adjustments made for major covariates. A p-value of less than 0.05 was considered statistically significant. All statistical analyses were performed using R software package version 3.3.2 (\u0026lt;\u0026thinsp;\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttp://www.R-project.org\u0026gt;\u003c/span\u003e\u003cspan address=\"http://www.R-project.org%3E\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e, The R Foundation) and Free Statistics software version 1.9.2.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003e\u003cstrong\u003eClinical Characteristics and Treatment Outcomes of the Study Population\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA total of 138 patients with severe traumatic brain injury (sTBI) were ultimately included in this study. Among them, 82.6% (114/138) were male, and 17.4% (24/138) were female, with a mean age of 56.8±16.5 years. The main comorbidities included: epidural hematoma (51.4%), basal skull fracture (50.7%), subdural hematoma (38.4%), skull fracture (34.1%), and subarachnoid hemorrhage (21.7%). The distribution of comorbidity combinations is detailed in Figure 3. The baseline characteristics were well-balanced between groups (see Table 1). There was no significant difference in age between the HLP group (n=45) and the supine group (n=93) (59.7±15.5 vs. 55.4±16.8, P=0.15).\u003c/p\u003e\n\u003cp\u003eOn day 7 of treatment, the HLP group had significantly lower levels of PaCO₂, PCT, WBC, days of mechanical ventilation, duration of antibiotic exposure, and tracheostomy rate compared to the supine group, with all p-values \u0026lt;0.05, indicating statistically significant differences (see Table 1 and Figure 4).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFactors Influencing Antibiotic Exposure in Severe Traumatic Brain Injury\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eUnivariate analysis results indicated that protective factors such as HLP (β= -2.93; 95% CI, -4.9 to -0.96; P=0.004), PaO₂ on day 1 (β= -0.02; 95% CI, -0.04 to 0; P=0.039), PaO₂ on day 7 (β= -0.02; 95% CI, -0.04 to 0; P=0.018), and P/F ratio (β= -0.01; 95% CI, -0.02 to 0; P=0.011) can reduce antibiotic exposure time in patients with severe traumatic brain injury (sTBI). Conversely, risk factors such as COPD (β= 9.72; 95% CI, 5.71 to 13.74; P\u0026lt;0.001) and days of mechanical ventilation (β=1.03; 95% CI, 0.92 to 1.14; P\u0026lt;0.001) can increase antibiotic exposure time in sTBI patients. (See Table 2)\u003c/p\u003e\n\u003cp\u003eMultivariate Regression Models Showed:\u003c/p\u003e\n\u003cp\u003eModel I (Without Adjusting for Any Covariates): HLP (β= -2.93; 95% CI, -4.9 to -0.96; P=0.004), PaO₂ on day 1 (β= -0.21; 95% CI, -0.41 to -0.01; P=0.039), and P/F ratio on day 7 (β= -0.12; 95% CI, -0.21 to -0.03; P=0.011) were independent protective factors. COPD (β= 9.72; 95% CI, 5.71 to 13.74; P\u0026lt;0.001) was a significant risk factor.\u003c/p\u003e\n\u003cp\u003eModel II (Adjusted for Age and Gender): HLP (β= -3.17; 95% CI, -5.13 to -1.22; P=0.002) and P/F ratio on day 7 (β= -0.11; 95% CI, -0.2 to -0.01; P=0.027) remained protective factors. COPD (β= 9.69; 95% CI, 5.43 to 13.94; P\u0026lt;0.001) remained a significant risk factor.\u003c/p\u003e\n\u003cp\u003eModel III (Further Adjusted for Age, Gender, COPD, PaO₂ on Day 1, and P/F on Day 7): HLP (β= -2.58; 95% CI, -4.44 to -0.71; P=0.008) remained a protective factor for antibiotic exposure time in sTBI patients. COPD (β= 8.78; 95% CI, 4.42 to 13.13; P\u0026lt;0.001) remained a significant risk factor for antibiotic exposure time in sTBI patients. (See Table 3)\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis study, through a retrospective cohort analysis, has for the first time confirmed that High Lateral Position (HLP) can significantly reduce the duration of antibiotic exposure in patients with severe traumatic brain injury (sTBI) complicated by aspiration pneumonia by 2.9 days (P\u0026thinsp;=\u0026thinsp;0.008). It also decreases the duration of mechanical ventilation (7.0 vs. 9.0 days) and the rate of tracheostomy (6.7% vs. 20.4%). Considering that the average daily cost of antibiotics in the ICU of this country is approximately 500\u0026ndash;800 units of the national currency per day\u003csup\u003e\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u003c/sup\u003e, it is estimated that each patient can save medical costs of 1450\u0026ndash;2320 units of the national currency. Compared with prone positioning (PP), HLP has greater advantages in maintaining intracranial pressure (ICP) stability\u003csup\u003e\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e,\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e\u003c/sup\u003e,and does not affect neurological monitoring, with convenient pupil assessment. This finding provides important evidence-based support for optimizing the positional management of sTBI patients and reveals the potential value of HLP in reducing the risk of multidrug resistance and medical costs.\u003c/p\u003e \u003cp\u003eIt is worth noting that although the 28-day mortality rate in the HLP group was lower than that in the supine group (8.9% vs. 18.3%), the difference did not reach statistical significance (P\u0026thinsp;=\u0026thinsp;0.15). This may be related to the following factors: (1) The limited sample size of this study (n\u0026thinsp;=\u0026thinsp;45 in the HLP group) led to insufficient statistical power; (2) Mortality is influenced by multiple factors, such as the initial GCS score and secondary brain injury events. Additionally, this study did not include subgroup analyses based on injury severity; (3) The 28-day observation window may not be sufficient to capture the long-term survival benefits of positional interventions.The Guidelines for the Management of Severe Traumatic Brain Injury\u003csup\u003e\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e\u003c/sup\u003e indicate that the 90-day mortality rate in sTBI patients is significantly associated with early respiratory management strategies, suggesting that future studies should extend the follow-up period. Moreover, the potential impact of HLP on the function of organs other than the lungs, such as the intestinal barrier and immune regulation, remains unclear. This uncertainty may limit the extent to which HLP can improve overall prognosis.\u003c/p\u003e \u003cp\u003ePatients with sTBI are prone to weakened ciliary movement in the airways, suppressed cough reflex, and retained secretions due to the inhibition of the respiratory center, the use of sedatives, and mechanical ventilation. This leads to the accumulation of large amounts of viscous secretions in the deep bronchi\u003csup\u003e\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e\u003c/sup\u003e. This accumulation creates a vicious cycle of \u0026ldquo;infection\u0026ndash;inflammation\u0026ndash;reinfection,\u0026rdquo; which further delays recovery and prolongs ICU stays. It also increases the risk of long-term sequelae, physical, psychological, and psychiatric complications, as well as cognitive impairments\u003csup\u003e\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e\u003c/sup\u003e. HLP breaks this cycle through its anatomical advantages. When patients are positioned in HLP, the bronchial openings of the upper lung are oriented downward, allowing airway secretions to drain into the larger airways under the influence of gravity. This reduces the accumulation of secretions caused by gravity, prevents pulmonary edema and sputum retention, and decreases the risk of infection\u003csup\u003e\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e,\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e\u003c/sup\u003e. In this study, the HLP group had a significant reduction in PaCO₂ on day 7 (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05), indicating improved efficiency of secretion clearance, which is consistent with the study by Wang QY et al\u003csup\u003e\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e\u003c/sup\u003e. Additionally, the high lateral position increases the expansion of the thoracic cage, enhances the coordinated action of the abdominal and diaphragmatic muscles, and improves peak expiratory flow (PEF), thereby facilitating sputum expulsion and reducing the risk of infection due to pulmonary insufficiency\u003csup\u003e\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e\u003c/sup\u003e. Moreover, when in the HLP position, pulmonary blood flow to the gravity-dependent areas increases by approximately 25% compared to the supine position. This provides better support for blood flow to the lung bases, while ventilation in the non-gravity-dependent alveoli is more adequate. This physiological effect reduces local hypoxia and atelectasis and lowers the risk of infection caused by immune suppression\u003csup\u003e\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eIt is worth noting that patients with comorbid COPD had the highest risk of prolonged antibiotic exposure (β\u0026thinsp;=\u0026thinsp;8.78, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001). This may be related to the pathological characteristics of COPD\u0026mdash;chronic airway inflammation, progressive airflow limitation, and excessive mucus secretion, which lead to secondary infections, worsening airway inflammation, and a vicious cycle of mucus hypersecretion and inflammation that reduces lung function\u003csup\u003e\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e\u003c/sup\u003e. Patients with frequent acute exacerbations of COPD are more prone to multidrug-resistant infections\u003csup\u003e\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e\u003c/sup\u003e.HLP may interrupt this process by facilitating early extubation (a reduction of 2 days in mechanical ventilation) and lowering inflammatory markers (PCT\u0026darr;0.3 ng/mL, WBC\u0026darr;2.0\u0026times;10⁹/L). This is consistent with the argument proposed by Kong L et al\u003csup\u003e\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e\u003c/sup\u003e that HLP can allow for more effective drainage of airway secretions, enhance the anti-inflammatory effects of antibiotics, effectively control pulmonary infections, shorten the window for controlling pulmonary infections, and better advance the implementation of invasive-to-non-invasive sequential weaning protocols. It also complements the \u0026ldquo;short-course antibiotic strategy\u0026rdquo; proposed by Kubo K et al\u003csup\u003e\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e\u003c/sup\u003e, providing a non-pharmacological intervention pathway for the prevention and control of multidrug resistance in patients with traumatic brain injury.\u003c/p\u003e \u003cp\u003eThe Neurocritical Care Society (NCS) 2023 guidelines recommend a head-elevated position of 15\u0026ndash;30\u0026deg; for patients with sTBI to balance intracranial pressure (ICP) and lung protection\u003csup\u003e\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e\u003c/sup\u003e, but they do not specify the angle for lateral positioning. This study provides direct evidence for the safety and efficacy of a 90\u0026deg; high lateral position (HLP). It is suggested that future guidelines consider incorporating HLP as an option for positional management in patients with sTBI.\u003c/p\u003e \u003cp\u003eHowever, this study has certain limitations. First, it is a retrospective analysis of treatment data from past patients. Although multivariate adjustments were made, unrecorded confounding factors such as sputum viscosity and suctioning frequency may have influenced the results. Although we statistically corrected for bias, we cannot rule out other unmeasured or uncollected confounding factors that may affect treatment outcomes. For example, respiratory mechanics such as transpulmonary pressure and airway resistance were not recorded during treatment, nor were long-term neurological function data such as the 90-day Glasgow Outcome Scale (GOS) score. We were also unable to further explore the impact on airway resistance and lung ventilation. Additionally, the effects of interventions such as percussion and vibration therapy and fiberoptic bronchoscopy on airway secretion drainage were not considered. These factors could all influence the final observed outcomes. The single-center sample of 138 patients may limit statistical power, and extrapolating the results to non-sTBI patients should be done with caution. Future research should conduct multicenter randomized controlled trials (RCTs) and include the following improvements: (1) Using electrical impedance tomography (EIT) to dynamically monitor lung ventilation distribution; (2) Combining microbiome analysis to study the evolution of antibiotic resistance spectra; (3) Developing a standardized operating procedure (SOP) for HLP, including position angle (90\u0026deg;\u0026plusmn;5\u0026deg;), turning frequency, and pressure ulcer risk stratification monitoring. By integrating multidimensional assessments of mechanical ventilation, infection management, and health economics, the translation of HLP from evidence-based medicine to clinical practice can be further advanced.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eThe results of this retrospective observational study indicate that the High Lateral Position (HLP) is associated with a reduction in antibiotic exposure time in patients with severe traumatic brain injury. The data show that patients receiving HLP had an average reduction of approximately 2.9 days in antibiotic use compared to those in the conventional supine position, with a trend towards fewer days of mechanical ventilation and a lower rate of tracheostomy. These associations may be achieved through mechanisms such as improved secretion drainage, optimized ventilation/perfusion ratio, and reduced risk of aspiration.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eHLP\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eHigh Lateral Position\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eCOPD\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003echronic pulmonary disease\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003esTBI\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eSevere Traumatic Brain Injury\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eTBI\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eTraumatic Brain Injury\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003ePP\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eprone positioning\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eAPACHE II\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eAcute Physiology and Chronic Health Evaluation II score\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eGCS\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eGlasgow coma scale\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eICU\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eintensive care unit\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003ePCT\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eprocalcitonin\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eSOFA\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eSequential Organ Failure Assessment\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eMAP\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003emean arterial pressure\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eRASS\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eRichmond Agitation-Sedation Scale\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eP/F\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ePaO2/FiO2\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eWBC\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ewhite blood count\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eHBP\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ehypertension or high Blood pressure\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eDM\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ediabetes mellitus\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eCKD\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003echronic kidney disease\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eCHD\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ecoronary heart disease\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eCI\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003econfidence intervals\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eIQR\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003einterquartile range\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003ePEF\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ePeak Expiratory Flow\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eSOP\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eStandard Operating Procedure\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003eAcknowledgements\u003c/p\u003e\n\u003cp\u003eThe authors thank Fujian Provincial Hospital\u0026rsquo;s intensive care units staff for their support and guidance in performing this study. Additionally, we obliged thank the Free Statistics team (Beijing, China) for providing technical assistance and practical data analysis and visualization tools.\u003c/p\u003e\n\u003cp\u003eFunding\u003c/p\u003e\n\u003cp\u003eThis work was supported by the Scientific Foundation of Fujian Health Department (Grant No.2020QNB006 ), the Startup Fund for scientific research, Fujian Medical University (Grant No.2020QH1139 and 2021QH1285).\u003c/p\u003e\n\u003cp\u003eAuthor information\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors and Affiliations\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eZhongbao Lin1#, RN, Dandan Chen2#,RN, Mei Ye1, RN, Xincai Wang1, MD, Bin Shao3*,MD,Long Huang1*,MD.\u003c/p\u003e\n\u003cp\u003e\u003csup\u003e1\u003c/sup\u003eFujian Provincial Hospital Affiliated to Fuzhou University, Shengli Clinical Medical College of Fujian Medical University, Department of Critical Care Medicine, Fuzhou 350001, P. R. China.\u003c/p\u003e\n\u003cp\u003e\u003csup\u003e2\u003c/sup\u003eFujian Provincial Hospital Affiliated to Fuzhou University, Shengli Clinical Medical College of Fujian Medical University, Department of Respiratory and Critical Care Medicine, Fuzhou 350001, P. R. China.\u003c/p\u003e\n\u003cp\u003e\u003csup\u003e3\u003c/sup\u003eFujian Provincial Hospital Affiliated to Fuzhou University, Shengli Clinical Medical College of Fujian Medical University , Department of Rehabilitation, Fuzhou 350001, P. R. China.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eContributions\u003c/strong\u003e\u003cbr\u003e\u0026nbsp;Long Huang and Bin Shao participated in study design, supervised data analysis, and revised the manuscript. Zhongbao Lin and Dandan Chen contributed equally to data collection, clinical intervention implementation, and preliminary statistical analysis. Mei Ye participated in patient management, nursing care, and clinical data organization. Xincai Wang performed radiological assessments (e.g., chest CT/X-ray interpretation) and critical care protocol design. Bin Shao provided expertise in rehabilitation strategies and long-term complication prevention. Long Huang conducted multivariate regression modeling and statistical validation using R/Free Statistics software. Zhongbao Lin and Dandan Chen collaborated on drafting the methods and results sections. All authors participated in manuscript proofreading and approved the final version.Long Huang and Xincai Wang acquired financial support from the Scientific Foundation of Fujian Health Department (Grant No.2020QNB006) and Fujian Medical University (Grants No.2020QH1139, 2021QH1285).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCorresponding authors\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eCorrespondence to Bin Shao or Long Huang.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics Approval\u003c/strong\u003e\u003cbr\u003e\u0026nbsp;The studies involving human participants were reviewed and approved by the IRB of Shengli Clinical Medical College of Fujian Medical University with the ethical approval number K2022-09- 061. Written informed consent for participation was not required for this study in accordance with the national legislation and the institutional requirements.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll authors have reviewed the manuscript and approved its submission for publication.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll data generated or used during the study are available from the corresponding author by request.\u003cstrong\u003e\u003cbr\u003e\u003c/strong\u003e\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eMax, J. E. et al. 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[Effect of lateral position ventilation combined with vibration sputum drainage on patients with acute respiratory distress syndrome: a prospective randomized controlled trial]. \u003cem\u003eZhonghua Wei Zhong Bing Ji Jiu Yi Xue\u003c/em\u003e. \u003cb\u003e30\u003c/b\u003e, 240\u0026ndash;245 (2018).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKubo, K., Kondo, Y., Yoshimura, J., Kikutani, K. \u0026amp; Shime, N. Short- versus prolonged-course antibiotic therapy for sepsis or infectious diseases in critically ill adults: a systematic review and meta-analysis. \u003cem\u003eInfect. Dis. (Lond)\u003c/em\u003e. \u003cb\u003e54\u003c/b\u003e, 213\u0026ndash;223 (2022).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLulla, A. et al. Prehospital Guidelines for the Management of Traumatic Brain Injury \u0026ndash;\u0026thinsp;3rd Edition. \u003cem\u003ePrehosp Emerg. Care\u003c/em\u003e. \u003cb\u003e27\u003c/b\u003e, 507\u0026ndash;538 (2023).\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003eTables 1 to 3 are available in the Supplementary Files section.\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Severe traumatic brain injury, High lateral position, Antibiotic exposure time, Aspiration pneumonia","lastPublishedDoi":"10.21203/rs.3.rs-6365655/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6365655/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003ePatients with severe traumatic brain injury (sTBI) frequently require mechanical ventilation and develop aspiration pneumonia, leading to prolonged antibiotic use. This study evaluates whether High Lateral Position (HLP) reduces antibiotic exposure duration in sTBI patients. Data from 138 mechanically ventilated sTBI patients with aspiration pneumonia (January 2023\u0026ndash;June 2024) were retrospectively analyzed. Patients were stratified into HLP (n\u0026thinsp;=\u0026thinsp;45) and non-HLP (n\u0026thinsp;=\u0026thinsp;93) groups. Linear regression models assessed associations between HLP and antibiotic exposure. HLP significantly reduced antibiotic duration (β=\u0026minus;2.58; 95% CI: \u0026minus;4.44 to \u0026minus;\u0026thinsp;0.71; P\u0026thinsp;=\u0026thinsp;0.008) and mechanical ventilation days (7.0 vs. 9.0, P\u0026thinsp;=\u0026thinsp;0.004). Chronic obstructive pulmonary disease (COPD) increased antibiotic exposure (β\u0026thinsp;=\u0026thinsp;8.78; 95% CI: 4.42\u0026ndash;13.13; P\u0026thinsp;\u0026lt;\u0026thinsp;0.001). HLP also lowered tracheostomy rates (6.7% vs. 20.4%, P\u0026thinsp;=\u0026thinsp;0.038). These findings suggest HLP optimizes secretion drainage and reduces pulmonary complications, offering a cost-effective strategy to mitigate antibiotic resistance.\u003c/p\u003e","manuscriptTitle":"The Effect of High Lateral Position on Antibiotic Exposure Duration in Patients with Severe Traumatic Brain Injury: A Retrospective Observational Cohort Study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-05-09 11:00:06","doi":"10.21203/rs.3.rs-6365655/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"3a602eb6-acca-4d96-a53e-86d342579889","owner":[],"postedDate":"May 9th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":48065440,"name":"Health sciences/Medical research"},{"id":48065441,"name":"Health sciences/Neurology"}],"tags":[],"updatedAt":"2025-07-14T14:23:19+00:00","versionOfRecord":[],"versionCreatedAt":"2025-05-09 11:00:06","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-6365655","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6365655","identity":"rs-6365655","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}