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ROSC after death: The Lazarus syndrome

What EMS providers need to know about the physiology behind the Lazarus syndrome to ensure a patient is deceased before declaring death


The Lazarus syndrome usually occurs within 10 minutes of CPR cessation. Therefore, many recommend monitoring a patient for 10 minutes after CPR is stopped to ensure that they are truly deceased.

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Recently, staff at a Detroit funeral home found a 20-year-old woman was breathing after paramedics had declared her dead. The paramedics performed CPR and other resuscitation measures for 30 minutes before determining she did not have signs of life, according to a department statement. Read more.

The Lazarus syndrome is the return of spontaneous circulation (ROSC) after CPR has been stopped. It is also known as autoresuscitation and was first reported in 1982 [1-3]. Since then, there have been several case reports of the dead coming back to life following cardiac arrest and even having good long-term outcomes. Although rare, it’s possible that you have already seen or will experience this phenomenon during your EMS career.

Physiology of the Lazarus syndrome

The exact mechanism behind the Lazarus syndrome is unknown but there are a few theories behind various cases:

  • Air trapping. Rapid ventilation rates lead to lung hyperinflation and air trapping, which decreases venous return. This is believed to be more common in those with pre-existing airway disease. Once ventilation is stopped, venous return may be restored, leading to spontaneous circulation.
  • Drug delay. Drugs injected through a peripheral line may not be able to reach the heart because of high intrathoracic pressure that occurs with positive pressure ventilation. Once PPV is stopped, intrathoracic pressure decreases, which could allow the drugs to reach the heart. Additionally, there could be a delay in drug effect in a severely acidotic patient.
  • Spontaneous plaque dislodgement. The plaque in the coronary artery may dislodge spontaneously after CPR is stopped, leading to restored circulation.
  • Untreated reversible causes. Inadequately treated reversible causes of cardiac arrest such as acidosis or hyperkalemia could resolve, leading to restored circulation.
  • Myocardial stunning. Myocardial dysfunction following myocardial ischemia can last several hours before normal heart function returns.
  • Transient asystole. Transient asystole can happen after defibrillation, which is why it’s important to continue resuscitation after defibrillation.

How to recognize death

As weird as it sounds, death is often defined differently in the medical field. For EMS, it is usually defined as the cessation of respiration and circulation. The Lazarus syndrome usually occurs within 10 minutes of CPR cessation. Therefore, many recommend monitoring a patient for 10 minutes after CPR is stopped to ensure that they are truly deceased.

3 ways to confirm death

Here are three ways EMS providers can ensure they are not surprised by the Lazarus syndrome:

  1. Ensure that you are ventilating appropriately, not hyperventilating your patient
  2. Remember the reversible causes of cardiac arrest and ensure that you are treating for them
  3. Once CPR has stopped, monitor the patient for 10 minutes to confirm they haven’t auto resuscitated after you have declared them deceased

Read more: Mich. woman found alive by funeral home staff after FD medics declared her dead


1. Adhiyaman V, Adhiyaman S and Sundaram R. The Lazarus phenomenon. Journal of the Royal Society of Medicine, 2007. 100(12): 552-557.

2. Gordon L, Pasquier M, Brugger H and Paal P. Autoresuscitation (Lazarus phenomenon) after termination of cardiopulmonary resuscitation – a scoping review. Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine, 2020. 28(14).

3. Kuisma M, Salo A, Puolakka J, et al. Delayed return of spontaneous circulation (the Lazarus phenomenon) after cessation of out-of-hospital cardiopulmonary resuscitation. Resuscitation, 2017. 118: 107-111.

This article, originally published in August 2020, has been updated.

Marianne Meyers, BS, is a third-year medical student at the University of Washington School of Medicine interested in pursuing emergency medicine. Previously, she was a member of the Santa Clara University collegiate EMS squad where she received her B.S. in Public Health Science. Additionally, she has worked with the King County Public Health Department in Seattle, Washington studying EMT naloxone administration.