To the Editor:-The case report by Frolich is one of the best documented cases of spontaneous recovery after discontinuation of cardiopulmonary resuscitation (CPR). [1] More than 25 such cases have been reported, including at least eight patient discharged neurologically intact. [2] One case published in Anesthesiology introduced the term "Lazarus phenomenon" for such events. [3] However, we would argue that the case of Harden et al. [4] should not be regarded as a true Lazarus phenomenon because there is no indication that CPR had been stopped at the time when spontaneous conversion of ventricular fibrillation occurred.

With regard to prevention of Lazarus phenomena, Frolich suggests to continue CPR until ineffectiveness has been shown by a decreasing pH with adequate ventilation. [1] Although this approach is probably correct, there are no defined pH values below which resuscitation can be considered futile. In the case of Fumeaux et al., [5] the patient survived neurologically intact after cessation of CPR at a pH of 6.54. An alternative approach might be end-tidal carbon dioxide. Its use for therapeutic and prognostic decisions during CPR was first proposed by Eisenmenger, [6,7] first used in humans by Leigh et al., [8] and studied in detail by Smalhout. [9] In the last 20 years there have been several studies on capnography during CPR. [10] Values greater than 10–15 mmHg indicate a favorable prognosis and should preclude termination of CPR. Unfortunately, there are no capnography data in the Lazarus cases published to date, including ours and that of Frolich. [1,2]

Wolfgang H. Maleck, A.R.Z.T.

Swen N. Piper, M.D.

Department of Anesthesiology; Klinikum; D-67063 Ludwigshafen, Germany;

(Accepted for publication March 25, 1999.)

Frolich MA: Spontaneous recovery after discontinuation of intraoperative cardiopulmonary resuscitation. Anesthesiology 1998; 89:1252-3
Maleck WH, Piper SN, Triem J, Boldt J, Zittel FU: Unexpected return of spontaneous circulation after cessation of resuscitation (Lazarus phenomenon). Resuscitation 1998; 39:125-8
Bray JG. The Lazarus phenomenon revisited (letter). Anesthesiology 1993; 78:991.
Harden K, Mackenzie IL, Ledingham IM: Spontaneous reversion of ventricular fibrillation (letter). Lancet 1963; 2:1140-2
Fumeaux T, Borgeat A, Cuenoud PF, Erard A, de Werra P: Survival after cardiac arrest and severe acidosis (pH = 6.54) (letter). Intensive Care Med 1997; 23:594.
Eisenmenger R: Tierversuche mit dem Apparat zur Erzielung kunstlicher Atmung, Biomotor. Wien Klin Wochenschr 1929; 42:1502-3
Eisenmenger R: Saug- und Druckluft uber dem Bauch, deren Wirkung und Anwendung. Wien Med Wochenschr 1939; 89:861-4
Leigh MD, Jenkins LC, Belton MK, Lewis GB: Continuous alveolar carbon dioxide analysis as a monitor of pulmonary blood flow. Anesthesiology 1957; 18:878-82
Smalhout B: Capnografie bij de diagnostiek, operatie en nabehandeling van neurochirurgische aandoeningen. Utrecht, The Netherlands, M.D. Thesis, 1967, pp 72-107 and 425-433
Ward KR, Yealy DM: End-tidal carbon dioxide monitoring in emergency medicine, part 2: Clinical applications. Acad Emerg Med 1998; 5:637-46