Skeletal muscle oxygenation during cardiopulmonary resuscitation as a predictor of return of spontaneous circulation: a pilot study

Background: Near-infrared spectroscopy (NIRS) provides regional tissue oxygenation (rSO 2 ) even in pulseless states such as out-of-hospital cardiac arrest (OHCA). Brain rSO 2 seems to be important predictor of return of spontaneous circulation (ROSC) during cardiopulmonary resuscitation (CPR). Aim of our study was to explore feasibility for monitoring and detecting changes of skeletal muscle rSO 2 during resuscitation.MethodsSkeletal muscle and brain rSO 2 were measured by NIRS (SenSmart Model X-100, Nonin, USA) during CPR in adult patient with OHCA. Start (basal) rSO 2 , maximal during CPR (maximal), difference between maximal-minimal rSO 2 (delta-rSO 2 ), and at the end of CPR (end-CPR rSO 2 ) were recorded. Patients were divided into ROSC and NO-ROSC group.Results20 patients (age: 66.0ys (60.5–79.5), 65% male) with OHCA (50% witnessed, 70% BLS, time to ALS 13.5min (11.0–19.0)) were finally analyzed. 10 patients were excluded due to violation of protocol or technical difficulties. ROSC was confirmed in 5 (25%) patients. Basal, maximal and end-CPR skeletal muscle rSO 2 were higher in ROSC compared to NO-ROSC group (49.0% (39.7–53.7) vs. 15.0% (12.0-25.2), p = 0.006; 76.0% (52.7–80.5) vs. 34.0% (18.0-49.5), p = 0.005; 72.0% (48.7–74.7) vs. 16.0% (12.0–35.0), p = 0.002, respectively). There was weak relationship between time of collapse and basal skeletal muscle rSO 2 in witnessed OHCA (n = 7, rho: -0.750, p = 0.0522). There was correlation between maximal skeletal muscle and brain rSO 2 (n = 18, rho: 0.578, P = 0.0121).ConclusionsRecording of skeletal muscle rSO 2 during CPR in patients with OHCA is feasible. Basal, maximal and end-CPR skeletal muscle rSO2 were higher in ROSC compared to NO-ROSC group.Clinical trial registration number:ClinicalTrials.gov, NCT04058925, registered on: 16th August 2019. URL of trial registry record: https://www.clinicaltrials.gov/ct2/show/NCT04058925?titles=Tissue+Oxygenation+During+Cardiopulmonary+Resuscitation+as+a+Predictor+of+Return+of+Spontaneous+Circulation&draw=2&rank=1