We believe this is the first case of survival to hospital admission in a patient with pulseless electrical activity (PEA) who was initially found to have both cardiac standstill and an ETCO
2 of less than 10 mmHg. In a study of 70 cardiac arrest patients (36 in asystole and 34 in PEA on the cardiac monitor), 59 were found to have no sonographic cardiac activity. None of these patients experienced ROSC [
2]. A larger study of 169 cardiac arrest patients found that none of the 136 patients with cardiac standstill on echo survived, regardless of their electrocardiogram cardiac rhythm [
3]. Capnography has been studied in cardiac arrest patients, and a study of 150 patients during cardiac arrest noted no survivors with an ETCO
2 of less than 10 mmHg [
4]. In all 115 nonsurvivors an ETCO
2 of less than 10 mmHg had been measured, and all 35 survivors had ETCO
2 levels above 18 mmHg. Capnography has been studied in emergency department patients in combination with bedside sonography as well. In a study of 102 cardiac arrest patients (35 in asystole, 46 in PEA, 3 in ventricular tachycardia, and 5 in ventricular fibrillation on the cardiac monitor), the presence of cardiac activity as well as ETCO
2 were studied as predictors of survival [
5]. The mean ETCO
2 level for survivors was 35 mmHg compared to 13.7 mmHg for those without ROSC. In our report, a single patient with PEA and a single patient in asystole on the cardiac monitor survived to hospital admission; all survivors had ETCO
2 levels above 16 mmHg. Table
1 summarizes the survival from cardiac arrest in patients without cardiac activity on bedside sonography.
Table 1
Summary of survival from cardiac arrest in patients without cardiac activity (CA) on bedside sonography
Blaivas and Fox (2001) [ 3] | 0/20 | 0/65 | 0/51 | 0/136 |
| 0/23 | 0/36 | NA | 0/59 |
| 1/23 | 1/32 | 0/4 | 2/59 |
Total | 1/66 | 1/133 | 0/55 | 2/254 |
This patient may represent a false negative (+ROSC in the setting of negative echo and ETCO2) which was not demonstrated in earlier studies due to a lack of power. Alternatively, the patient’s youth and lack of past medical history, coupled with a witnessed arrest, may have granted a better prognosis than the patients enrolled in prior studies, who tended to be older, have comorbidities, and whose codes often began in the field. As greater numbers of patients are enrolled in studies utilizing ETCO2 and bedside echo as prognostic indicators, we should develop a better sense of their true accuracy in prognosis as well as their value in guiding resuscitative efforts in the ED and ICU settings.