One hypothesis for the phenomenon is that a chief factor (though not the only one) is the buildup of pressure in the chest as a result of cardiopulmonary resuscitation (CPR).
[5] Velma Thomas, 59, of Nitro, West Virginia, United States holds the record time for recovering from clinical death.
Her son, Tim Thomas, stated that "her skin had already started hardening, her hands and toes were curling up, they were already drawn".
[17][18] The Lazarus phenomenon raises ethical issues for physicians, who must determine when medical death has occurred, resuscitation efforts should end, and postmortem procedures such as autopsies and organ harvesting may take place.
[2] Medical literature has recommended observation of a patient's vital signs for five to ten minutes after cessation of resuscitation before certifying death.