Focused echocardiography and capnography during resuscitation from pulseless electrical activity after out-of-hospital cardiac arrest

Abstract

Introduction: The study evaluated the ability of focused echocardiography (F-ECHO) and capnography to differentiate between pulseless electrical activity (PEA) and pseudo-PEA during resuscitation from out-of-hospital cardiac arrest (OHCA). Methods: Patients in PEA, with stable values of end-tidal PCOT 2 (PETCO 2) during compression pauses, underwent subxiphoid F-ECHO examinations during pauses for carotid pulse evaluation, assessing for the presence or absence of cardiac kinetic activity (synchronous myocardial wall and valvular movement). Patients with stable PETCOT 2 during the time of F-ECHO examinations who had cardiac kinetic activity underwent a compression pause of 15 seconds during which an additional 20 IU bolus of vasopressin and a 0.9% NaCl bolus were given. If pulselessness persisted after the 15-second pause, compressions were resumed. This group was denominated the F-ECHO group (November 2007 to October 2008, n = 16) and was compared with a NON-ECHO group (November 2005 to October 2007, n = 48) who also had PEA with stable PETCOT 2 and were managed according to 2005 European Resuscitation Council guidelines without F-ECHO. Results: There were no statistically significant differences between groups with regards to sex, suspected cause of arrest, initial cardiac rhythm, witnessed arrest, time elapsed before initiation of cardiopulmonary resuscitation (CPR), and bystander CPR. Primary outcome (ICU admission: 88% vs. 50%; adjusted values: OR = 22.4, 95% CI = 4.2 to 86.9, P <0.001) and secondary outcome (return of spontaneous circulation (carotid pulses palpable): 94% vs. 54%, adjusted: OR = 28.4, 95% CI = 3.9 to 96.1, P <0.001; 24- hour survival: 81% vs. 41%; adjusted: OR = 19.8, 95% CI = 3.1 to 72.6, P <0.001; hospital survival: 56% vs. 15%; adjusted values: OR = 31.4, 95% CI = 2.9 to 85.7, P <0.001; neurological outcome - CPC 1 (good cerebral performance) to CPC 2 (moderate cerebral disability): 50% vs. 8%; adjusted values: OR = 36.4, 95% CI = 4.8 to 115.4, P <0.001) were significantly beTer in the F-ECHO group. In the NON-ECHO group, significantly higher doses of epinephrine were needed (P = 0.009) and CPR lasted longer (P = 0.003). Conclusions: F-ECHO and capnography during PEA in OHCA facilitates return of spontaneous circulation, ICU admission, 24-hour survival, and hospital survival. This effect was aTributed to the ability to distinguish between PEA and pseudo-PEA and to institute appropriate treatment during CPR. The confirmation of these results in a large study is warranted.