Predictors of survival after cardiac or respiratory arrest in critical care units

Abstract

C ardiac arrest remains a major clinical and public health problem.1 Studies of cardiac arrest in volving patients admitted to non-critical care beds showed that survival has not improved despite 40 years of medical advances.2−4 Outside of critical care units, survival was substantially lower for nonwitnessed arrests than for witnessed arrests; for cardiac than for respiratory arrests; for arrests due to asystole or pulseless electrical activity than for those due to ventricular fibrillation or ventricular tachycardia; and for arrests occurring early in the morning than for those at other times of the day.2-4 How these data apply to approximately one-third of in-hospital cardiac arrests that occur in intensive care units (ICUs) is less clear.Arrests in ICUs might be expected to have increased survival because universal cardiac monitoring and a high nurse-to-patient ratio would mean that the arrests would be witnessed regardless of the time of day. On the other hand, survival might be expected to be lower because critical care patients have a high disease burden and experience arrests despite aggressive preemptive life support. Also, patients in a general ICU might be expected to have poorer survival than those in a coronary care or cardiovascular surgical ICU because they typically have primary noncardiac diagnoses; therefore, cardiac arrest in these patients implies cardiovascular collapse in addition to noncardiac illness (i.e., at least two-organ failure). 3,4 We evaluated survival outcomes during a five-year follow-up period among adult patients who experienced cardiac or respiratory arrest in ICUs at four hospitals. We also identified risk factors associated with decreased survival after 24 hours.

Cardiac arrest in the operating room requiring prolonged resuscitation

“…For CPR in critical care units, a more recent study reports a 26.7% survival to discharge, with mortality increasing with duration of CPR and only one-third of patients surviving CPR which lasted more than 45 min. 8 Neither ACLS nor European Resuscitation Council (ERC) guidelines commit to a maximum duration of CPR before considering continued resuscitation futile, and both seem to conclude that rules for clinical decision-making cannot be recommended due to lack of prospective validation. 9,10 Other guidelines suggest that patient context, setting of cardiac arrest, and promptness and quality of resuscitation are the most important factors to consider.…”

Cardiopulmonary Resuscitation Among Mechanically Ventilated Patients

“…Multiple prior studies have suggested that survival after in-hospital CPR is higher when CPR is received in monitored settings [11][12][13][14]. Our findings of worse outcomes in monitored ventilated patients can be fully explained by the fact that these prior studies did not restrict their analyses to ventilated patients, who have a much higher severity of illness than non-ventilated patients.…”

“…Thus, we cannot be certain that outcomes in Medicare beneficiaries have not also improved since 2005. Finally, we do not know the initial arrest rhythm, which is an important variable associated with survival [34], as survival rates are highest among patients with ventricular tachycardia or fibrillation [11][12][13]16,30,31,34,[36][37][38].…”

Effects of therapeutic hypothermia and kinetics of serum protein S100B after cardiopulmonary resuscitation

“…The duration of CPR, and initial cardiac activity did not significantly influence 30-day-mortality in our study, but earlier findings reported elevated mortality rate after nonshockable rhythms (20) and the duration of CPR as an independent predictor of mortality. (21,22) It is well known that the original ILCOR guideline recommended TH after ventricular fibrillation but for other rhythms the "may also be beneficial" statement was used. (6) In the present study, serum lactate levels in the TH group were significantly higher than in the NT group on ICU admission and in the 12 th and 36 th hours after ROSC.…”