1433: Lucas vs Manual CPR in Obese in-Hospital Cardiac Arrest: Survival Outcome

Introduction: Obesity is a growing global health concern that not only increases the risk of mortality but also complicates the clinical management of critically ill patients, particularly during cardiopulmonary resuscitation (CPR). This study aims to compare 24-hour and 60-day survival after in-hospital cardiac arrest (IHCA) in overweight (BMI ≥ 25 kg/m2) and obese patients (BMI ≥ 30 kg/m2) resuscitated with LUCAS assisted versus manual CPR, and to determine whether BMI (body mass index) modifies this association. Methods: Multicenter retrospective cohort of adult IHCA events at seven Mayo Clinic hospitals from January 2019 to January 2025. Cardiac arrests < 4 minutes or without a BMI record were excluded. IPTW (Inverse-probability-of-treatment weighting) adjusted for demographics, arrest location, and comorbidities. We first compared 24-hour and 60-day mortality between groups using IPTW-weighted logistic regression. To assess effect modification by BMI, we fitted analogous models with restricted cubic splines (knots at 25, 28, 37 kg/m2) and LUCAS × BMI interaction terms. The model choice was based on Akaike Information Criterion. Results: A total of 679 patients were included (manual CPR=595 and LUCAS assisted=84). In weighted analyses, 24-hour mortality did not differ significantly (OR 1.54; 95% CI: 0.94-2.53, p = 0.09), nor did 60-day mortality (OR 1.83; 95% CI: 0.92-3.64, p = 0.09). Spline models showed that 24-hour and 60 days mortality increased modestly between BMI 25-28 kg/m2 and then plateaued above 28 kg/m2 in both groups. No LUCAS × BMI interaction was significant (all p > 0.14), indicating consistent effects across the BMI spectrum. Conclusions: In overweight and obese IHCA patients, LUCAS-assisted mechanical CPR did not improve 24-hour or 60-day mortality versus high quality manual compressions, and effectiveness was independent of BMI.