Abstract 185: Regional Oxygen Saturation and Capnography Monitoring During Resuscitation After Cardiac Arrest in a Swine Pediatric ARDS Model

Abstract

Introduction: Survival and outcomes after cardiac arrest (CA) depend largely on the effectiveness of cardiopulmonary resuscitation (CPR). Traditional invasive methods of monitoring CPR can be challenging out-of-hospital and are lacking in more than 50% of in-hospital pediatric CA. Regional oxygen saturation (rSO 2 ) monitoring with Near Infrared Spectroscopy (NIRS) and volumetric capnography offers a noninvasive approach that could potentially overcome these challenges. Aim: To determine the feasibility and effectiveness of NIRS and volumetric capnography monitoring in a swine model of pediatric hypoxia induced CA. Approach: Juvenile pigs were sedated and mechanically ventilated. Mild to moderate Acute Respiratory Distress Syndrome (ARDS) was induced by continuous oleic acid infusion. Respiratory and hemodynamic variables were monitored using invasive and noninvasive (NIRS and capnography) monitoring to assess efficacy of CPR. Animals were randomized into one of the two groups: High-quality CPR (hqCPR) to achieve coronary perfusion pressure of 25-30 mmHg and low-quality CPR (lqCPR) to achieve coronary perfusion pressure of 10-15 mmHg. Trajectories over time were analyzed using regression analyses. The discriminatory ability to distinguish between groups based on trajectories were analyzed using receiver operating characteristics curve (ROC) analysis. Results: 39 animals (23±3 kg) were included in our study. In the hqCPR group, there are generally higher values for cerebral and renal rSO 2 , ETCO 2 , volume of CO 2 elimination (VCO 2 ), and carotid blood flow, compared to the lqCPR group (p<0.0001). Cerebral and renal rSO 2 values increase over time, while ETCO 2 , VCO 2 , and carotid flow values decrease in the hqCPR group. Cerebral rSO2 had a ROC AUC of 0.76 (95% CI: 0.58-0.94), whereas renal rSO2 had a ROC AUC of 0.54 (95% CI: 0.22-0.87) representing nearly no discrimination ability. ETCO 2 had a ROC AUC of 0.66 (95% CI: 0.49-0.84), whereas VCO 2 had a ROC AUC of 0.62 (95% CI: 0.38-0.85). Conclusions: Higher mean cerebral rSO2 values during CPR might be used to assess quality of CPR effectiveness and provide real-time adjustments as needed. This could guide healthcare providers in optimizing CPR quality and improving outcomes for cardiac arrest patients.