Factors affecting short- and long-term prognosis among 1069 patients with out-of-hospital cardiac arrest and pulseless electrical activity

Abstract

Aims: To describe the epidemiology, resuscitation factors and prognosis among a consecutive population of patients suffering from out-of-hospital cardiac arrest (OHCA) where pulseless electrical activity (PEA) was the first arrhythmia recorded on emergency medical services (EMS) arrival. Methods: Analysis of data collected prospectively on all patients regardless of age succumbing to OHCA during 1980–1997 in the community of Gothenburg where EMS initiated resuscitative measures. Results: 4662 patients with OHCA were attended by the EMS during the study period. Of these, 1069 (23%) were judged as having PEA as the first recorded arrhythmia; 158 (15%) of these were admitted alive to hospital and 26 (2.4%) were discharged alive. Survivors to discharge had a significantly larger share of bystander cardiopulmonary resuscitation (CPR) (28 vs. 8%, P=0.008), significantly higher levels of consciousness (8% awake vs. 0%, P<0.001) and higher median systolic blood pressure (145 vs. 106 mmHg, P<0.001) on arrival at hospital. No patient with unwitnessed cardiac arrest and PEA over 80 years old survived. Conclusion: Survival among patients suffering from OHCA and PEA is poor, especially among the elderly unwitnessed cases and those who do not receive bystander CPR. The latter seems to be of utmost importance among these patients.

Sumàrio

Objectivos: Descrever a epidemiologia, factores de ressuscitação e de prognóstico num grupo consecutivo de doentes vitimas de paragem cardı́aca pré-hospitalar (PCRPH) nos quais a primeira arritmia registada à chegada dos serviços de emergência médica (SEM) era dissociação electro-mecânica (DEM). Métodos: Análise dos dados registados prospectivamente em todos os doentes, independentemente da idade, vitimas de PCRPH no perı́odo de 1980–1997 na comunidade de Gotemburgo e nos quais os SEM iniciaram manobras de ressuscitação. Resultados: No perı́odo do estudo, os SEM socorreram 4662 doentes com PCRPH. Destes, 1069 (23%) foram julgados como tendo DEM como primeira arritmia registada; 158 (15%) destes foram admitidos com vida no hospital e 26 (2.4%) tiveram alta. Foi estatisticamente significativo nos sobreviventes até à alta, a execução manobras de Suporte Básico de Vida (SBV) por leigos, á chegada do SEM (28 vs. 8%, P=0.008), nı́veis de consciência significativamente maiores (8% acordados vs. 0%, P<0.001) e pressões sistólicas médias superiores (145 vs. 106 mmHg, P<0.001) à chegada ao hospital. Nenhum doente com mais de 80 anos e paragem cardı́aca testemunhada e DEM sobreviveu. Conclusão: A sobrevivência entre as vı́timas de PCREH e DEM é má, especialmente entre os casos presenciados em idosos e entre os que as testemunhas locais não iniciaram SBV. Esta última parece ser de importância fundamental para estes doentes.

Introduction

Pulseless electrical activity (PEA) is a frequent finding among patients succumbing to out-of-hospital cardiac arrest (OHCA). Clinical states with electrical activity and no detectable pulse were earlier referred to as electromechanical dissociation (EMD) [1], [2], [3], [4], [5], [6], [7], [8], [9]. PEA is a broader summary term adopted in the early 1990s and includes heterogeneous arrhythmias, pseudo-EMD, idioventricular rhythm, ventricular escape rhythms, postdefibrillation idioventricular rhythms and bradyasystolic rhythms [10]. The term PEA is described in the latest version of guidelines as ‘absence of a detectable pulse and the presence of some type of electrical activity other than ventricular tachycardia or ventricular fibrillation’ [10]. The implication of this definition is mainly descriptive since a variety of cardiac and non-cardiac diseases can generate PEA. The state of PEA does not however exclude the presence of myocardial contractile activity and measurable blood pressure [11], [12]. In relation to other arrhythmias involved in OHCA, less attention is paid to PEA/EMD in the literature. The prognosis for patients suffering from OHCA with PEA as initial arrhythmia is very depressing [12], [13], [14], [15], [16], but subgroups with a higher chance of survival are described [17], [18], [19].

The purpose of this study was to describe the epidemiology and resuscitation factors among a consecutive population of patients suffering from OHCA where PEA was the first arrhythmia noted on arrival of the EMS. We also identify subgroups with a higher chance of survival and subgroups in which resuscitation efforts can be regarded as less meaningful.