Abstract 248: The Paradoxical Association Between Pulmonary Edema and Survival with Favorable Neurological Function After Cardiac Arrest
Introduction: Pulmonary edema (PE) is a sign of heart failure. In a recent out-of-hospital cardiac arrest (OHCA) trial, the presence of PE was associated with increased survival with favorable neurological outcome (SFNO) [PE present (28/200 (14%) vs. no PE 119/1912 (6.2%), p<0.001). In subjects treated with standard (S) cardiopulmonary resuscitation (CPR), the presence of PE was associated with SFNO [PE 11/75 (14.7%) vs no PE 50/948 (5.3%), p=0.003]. PE was also associated with active compression decompression CPR plus an impedance threshold device (ACD+ITD) and SFNO rates [PE 17/125 (13.6%) vs no PE 69/964 (7.1%), p=0.020]. To help explain this paradox, we examined the relationship between PE in subjects reported to gasp or manifest agonal breathing during CPR. We hypothesized that gasping decreased intrathoracic pressure, enhanced venous return, lowered intracranial pressure, and in some cases induced PE.
Methods: Data related to the frequency of gasping and SFNO was available from 2007-2009 in the ResQTrial, a NIH-funded trial comparing S-CPR with ACD (ResQPUMP)+ITD(ResQPOD-16)( ACD+ITD manufacturer, Advanced Circulatory Systems, Roseville MN). PE was identified by prehospital fluid or secretions in the airway and/or roentgenographic evidence after hospital admission. SFNO was defined as a Modified Rankin Scale score ≤ 3 at hospital discharge.
Results: PE was more frequent in gasping subjects [30/212 (14.2%)] vs. non-gasping subjects [144/1660 (8.7%)], p<0.016). SFNO was associated with gasping in 49/207 (23.7%) subjects vs. 81/1649 (4.9%) for non gasping patients, p<0.001. PE was more frequent in the ACD+ITD group vs. S-CPR (125/1095 vs. 76/1037, p<0.001). PE was associated with gasping in the ACD+ITD group [24/119 (20.2%) vs 83/846 (9.8%), p=0.002] but not the S-CPR group [6/93 (6.5%) vs. 61/814 (7.5%), p=0.84].
Conclusions: PE frequency in OHCA was associated with a >2 fold higher rate of survival to hospital discharge with good brain function during S-CPR and ACD+ITD. Increased PE was associated with increased gasping during ACD+ITD but not S-CPR. Higher gasping rates leading to lower intrathoracic pressures may underlie the unanticipated association between increased PE and SFNO with ACD+ITD but not with S-CPR.
Author Disclosures: G. Debaty: None. T.P. Aufderheide: None. R.A. Swor: None. R.J. Frascone: None. M.A. Wayne: None. R.M. Domeier: None. M.L. Olinger: None. B.D. Mahoney: None. D. Yannopoulos: Research Grant; Significant; NIH 1R01HL123227-02; R01HL108926-04.
- © 2014 by American Heart Association, Inc.