Feature Articles A systematic review of autoresuscitation after cardiac arrest* K. Hornby, MSc; L. Hornby, MSc; S. D. Shemie, MD Objective: There is a lack of consensus on how long circulation ranging from a few seconds to 33 mins; however, continuity of must cease for death to be determined after cardiac arrest. The observation and methods of monitoring were highly inconsistent. lack of scientific evidence concerning autoresuscitation influ- For the eight studies reporting continuous electrocardiogram ences the practice of organ donation after cardiac death. We monitoring and exact times, autoresuscitation did not occur be- conducted a systematic review to summarize the evidence on the yond 7 mins after failed cardiopulmonary resuscitation. No cases timing of autoresuscitation. of autoresuscitation in the absence of cardiopulmonary resusci- Data Sources: Electronic databases were searched from date of tation were reported. first issue of each journal until July 2008. Conclusions: These findings suggest that the provision of Study Selection: Any original study reporting autoresuscitation, cardiopulmonary resuscitation may influence autoresuscitation. as defined by the unassisted return of spontaneous circulation after In the absence of cardiopulmonary resuscitation, as may apply to cardiac arrest, was considered eligible. Reports of electrocardiogram controlled organ donation after cardiac death after withdrawal of activity without signs of return of circulation were excluded. life-sustaining therapies, autoresuscitation has not been reported. Data Extraction: For each study case, we extracted patient The provision of cardiopulmonary resuscitation, as may apply to characteristics, duration of cardiopulmonary resuscitation, termi- uncontrolled organ donation after cardiac death, may influence nal heart rhythms, time to unassisted return of spontaneous observation time. However, existing evidence is limited and is circulation, monitoring, and outcomes. consequently insufficient to support or refute the recommended Data Synthesis: A total of 1265 citations were identified and, of waiting period to determine death after a cardiac arrest, strongly these, 27 articles describing 32 cases of autoresuscitation were supporting the need for prospective studies in dying patients. (Crit (age, 27–94 yrs). The studies came from 16 Care Med 2010; 38:1246–1253 ;32 ؍ included (n different countries and were considered of very-low quality (case KEY WORDS: organ donation; cardiac arrest; donation after car- reports or letters to the editor). All 32 cases reported autoresus- diac death; withdrawal of life support; cardiopulmonary resusci- citation after failed cardiopulmonary resuscitation, with times tation; autoresuscitation he physiologic transition from and other organ support or replacement after cardiac death ͓DCD͔, which is also life to death is a complex pro- technologies, has obscured our ability to referred to as nonheart-beating organ do- cess. The determination of distinguish between the seemingly discrete nation). With advances in both transplant death affects all physicians re- states of life and death. Yet, the practices of surgery and organ preservation techniques, Tgardless of specialty, and modern, sophisti- organ donation and transplantation neces- the practice of DCD has progressively in- cated medical technology has complicated sitate this distinction. The ethical norm for creased. DCD programs have developed rather than facilitated this process. The organ donation is the “dead donor rule,” throughout the world and now account for availability of life-sustaining interventions, which states that “vital organs should only the largest incremental increase in organ such as cardiopulmonary resuscitation be taken from dead patients and, correla- donation in active programs in the United (CPR), mechanical ventilation, extracorpo- tively, living patients must not be killed by States (2, 3). There is an ongoing, focused real life support, ventricular assist devices, organ retrieval” (1). For organ transplanta- attempt in the United States to increase the tion to be successful, the arrest of circula- number of DCD donors (4). Accompanying tion and resulting warm ischemic injury this renewed emphasis on DCD is the re- *See also p. 1377. (which occur at death and during organ quirement to determine death as rapidly as From Division of Critical Care (KH, LH, SDS), Mon- procurement and transplantation) must be possible after cardiac arrest to minimize treal Children’s Hospital, McGill University, Montreal, Quebec, Canada; Bertram Loeb Research Consortium minimized. This conundrum is partially any loss of circulation to the organs. This in Organ and Tissue Donation (KH, LH), Bertram Loeb overcome when death is determined using time pressure has forced the identification Chair in Organ and Tissue Donation (SDS), University of neurologic criteria, because the brain-dead of a precise waiting period that is long Ottawa, Ottawa, Canada. donor remains on a ventilator and circula- enough to ensure the person has died but Given the nature of this study, it was exempt from requiring approval of the Institutional Review Board of tion is maintained until surgical removal of short enough to maintain organ viability the McGill University Health Centre. organs. for transplantation. The authors have not disclosed any potential con- Organ donation from brain-dead donors Death is generally understood to be flicts of interest. continues to be the preferred source of or- based on the irreversible cessation of ei- For information regarding this article, E-mail: [email protected] gans for transplantation; however, one of ther brain function or circulatory and Copyright © 2010 by the Society of Critical Care the responses to the persistent shortage of respiratory functions and the determina- Medicine and Lippincott Williams & Wilkins organs has been the re-emergence of dona- tion of death is a clinical matter that DOI: 10.1097/CCM.0b013e3181d8caaa tion after cardiocirculatory death (donation should be made according to widely ac- 1246 Crit Care Med 2010 Vol. 38, No. 5 cepted guidelines established by expert to summarize the evidence on the timing al (31). Therefore, we conducted a systematic medical groups (5). In the absence of of AR. We hypothesized that insufficient review of the AR literature. organ donation, accepted medical prac- evidence exists to define the time limits Any original study that reported on the phe- tice for determining death after cardiac of AR and the provision of CPR confounds nomenon of AR was considered eligible for this arrest has not included standardized di- these limits. review. To identify all eligible studies, the follow- agnostic criteria or a specific time period ing electronic databases were searched (from date of first issue of each journal until July 22, of observation. In the setting of DCD, MATERIALS AND METHODS although recommendations exist for di- 2008): MEDLINE using PubMed, EMBASE using agnostic criteria, there is a lack of con- OVID, Web of Science, and the Cochrane Li- Definitions brary. The study language was limited to En- sensus on how long circulation and res- glish, French, German, and Spanish. We con- piration must cease for a person to be For the purposes of this review, irrevers- sulted a health sciences librarian to develop our determined dead (6–9). Internationally, ibility of circulatory and respiratory functions search strategies for each database (Appendix 1). this time period varies from 2–10 mins is defined as a state in which these functions All citations fulfilling the search criteria were (10). The historical influences on these cannot return on their own and will not be compiled and duplicate citations were elimi- timeframes include the 1995 Interna- restored by medical interventions (24, 25). nated. Citation titles and abstracts were scanned tional Maastricht Workshop (10 mins) CPR was defined as any resuscitative interven- independently by two reviewers (KH and LH) to (11), the 1992 Pittsburgh protocol (2 tion that could reestablish circulation, such as identify original and review articles reporting mins) (12), the 1997 US Institute of Med- the administration of artificial respiration, occurrences of AR. The full texts of these articles icine report (Ն5 mins) (13), and the 2001 cardiac compressions, cardiac resuscitation were retrieved and independently reviewed to Report of the Ethics Committee, Ameri- medications, and external or internal pace- assess study eligibility. In addition, the reference can College of Critical Care Medicine, and makers. We defined AR as the unassisted re- lists of these articles were independently exam- Society of Critical Care Medicine (Ն2 turn of spontaneous circulation (ROSC) after a ined to identify additional relevant articles. All mins but not Ͼ5 mins) (14). In a recent cardiac arrest. The ROSC was defined as one or disagreements were resolved by consensus. DCD pilot project in the United States, more of the following signs: heart sounds, Studies that were excluded were tracked and pulse (detected by palpation or Doppler), hearts from three severely brain-injured reasons for their exclusion were recorded. blood pressure (detected by invasive or nonin- newborns were removed for transplanta- We included all types of original studies, vasive methods), oxygenation (detected by tion soon after cardiac arrest (3 mins in regardless of the study type or quality. Lan- pulse oximetry), opening of the aortic valve guage restrictions were based on our ability to the first case and 75