Vital Signs After Cardiac Arrest Following Withdrawal of Life-Sustaining Therapy: A Multicenter Prospective Observational Study*

Abstract

OBJECTIVE: Controversies regarding the process and timing of the determination of death for controlled organ donation after circulatory death persist. This study assessed the feasibility of conducting a prospective, observational study of continuous monitoring of vital signs for 30 minutes after the clinical determination of death in five Canadian ICUs. Waveform data were analyzed. DESIGN: Prospective observational cohort study. SETTING: One pediatric and four adult Canadian ICUs. PATIENTS: One month of age or older, admitted to the ICU, and for whom a consensual decision to withdraw life-sustaining therapies had been made, with an anticipation of imminent death. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Invasive arterial blood pressure, electrocardiogram, and oxygen saturation plethysmography activity were recorded and reviewed for 30 minutes after declaration of death. Feasibility was assessed (recruitment, consent rate, protocol compliance, and staff satisfaction). Of 188 subjects screened over 16 months, 41 subjects were enrolled (87% consent rate). Data collection was complete for 30 subjects (73% protocol compliance). In four subjects, arterial blood pressure resumed following cessation of activity. The longest period of cessation of arterial blood pressure before resumption was 89 seconds. The duration of resumed activity ranged from 1 to 172 seconds. No cases of sustained resumption of arterial blood pressure activity were recorded, and no instances of clinical autoresuscitation were reported. In nearly all patients (27 of 30), electrocardiogram activity continued after the disappearance of arterial blood pressure. CONCLUSIONS: This is the first observational study to prospectively collect waveform data for 30 minutes after the declaration of death. A future larger study may support initial data suggesting that circulatory function does not resume after more than 89 seconds of absence. Furthermore, persistence of cardiac electrical activity with the documented absence of circulation may not be relevant to declaration of death.