[Lazarus phenomenon. Spontaneous return of circulation after cardiac arrest and cessation of resuscitation attempts].

BACKGROUND

In the medical literature the Lazarus phenomenon is defined as the spontaneous return of circulation (SROC) after cessation of cardio-pulmonary resuscitation. Based on published literature recommendations concerning the treatment of patients after cessation of resuscitation and reasons for the Lazarus phenomenon are discussed.

METHODS

A literature search in Medline, PubMed, Embase, Google Scholar and Google from 1982 to 2009 was carried out for the terms "Lazarus phenomenon", "cessation of cardiopulmonary resuscitation and return of spontaneous circulation (ROSC)", "spontaneous return of circulation (SROC)", "resuscitation and spontaneous defibrillation", "spontaneous recovery and cardiopulmonary resuscitation". Related secondary literature which was cited in the relevant articles was included as well as publications found in our personal literature base.

RESULTS

More than 10,000 articles and comments could be recovered and of these 45 were considered to be medically relevant articles (letters to the Editor, abstracts, case reports and literature reviews).

CONCLUSIONS

In the relevant medical literature, the Lazarus phenomenon is a rare occurrence. It seems to be a phenomenon which has often been described in non-medical literature but not published in medical literature. The pathophysiological mechanisms are poorly understood. In the literature several mechanisms are discussed which could be important for this phenomenon, e.g. autopositive end-expiratory pressure, hyperventilation and alkalosis, hyperkalemia, delayed action of drugs and unobserved minimal vital signs. In the literature it is recommended that patients should be passively monitored for at least 10 min after cessation of resuscitation. However, more scientific experimental investigations seem to be necessary to gain a better understanding of this phenomenon.