Hyperoxemic reperfusion after prolonged cardiac arrest in a rat cardiopulmonary bypass resuscitation model

Resuscitation. 2013 Jan;84(1):114-20. doi: 10.1016/j.resuscitation.2012.08.323. Epub 2012 Sep 14.


Background: The effect of hyperoxygenation at reperfusion, particularly in the setting of cardiac arrest, remains unclear. This issue was studied in a prolonged cardiac arrest model consisting of 25 min cardiac arrest in a rat resuscitated with cardiopulmonary bypass (CPB). The objective of this study was to determine the effect of hyperoxygenation following prolonged cardiac arrest resuscitation on mitochondrial and cardiac function.

Methods: Male Sprague-Dawley rats (400-450 g) were anesthetized with ketamine and xylazine and instrumented for closed chest cardiopulmonary bypass (CPB). Following a 25-min KCl-induced cardiac arrest, the animals were resuscitated by CPB with 100% oxygen. Three minutes after successful return of spontaneous circulation (ROSC), the animals received either normoxemic reperfusion (CPB with 40-50% oxygen) or hyperoxemic reperfusion (CPB with 100% oxygen) for 1 h. Post-resuscitation hemodynamics, cardiac function, mitochondrial function and immunostaining of 3-nitrotyrosine were compared between the two different treatment groups.

Results: At 1 h after ROSC, the hyperoxemic reperfusion group had a significant higher mean arterial pressure, less metabolic acidosis and better diastolic function than the normoxemic reperfusion group. Cardiac mitochondria from the hyperoxemic reperfusion group had a higher respiratory control ratio (RCR) and cardiac tissue showed less nitroxidative stress compared to the normoxemic reperfusion group.

Conclusions: One hour of hyperoxemic reperfusion after 25 min of cardiac arrest in an in vivo CPB model resulted in significant short-term improvement in myocardial and mitochondrial function compared with 1h of normoxemic reperfusion. This myocardial response may differ from previously reported post-arrest hyperoxia mediated effects following shorter arrest times.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Analysis of Variance
  • Animals
  • Blood Gas Analysis
  • Cardiopulmonary Bypass / methods*
  • Heart Arrest / physiopathology
  • Heart Arrest / therapy*
  • Hemodynamics
  • Hyperoxia*
  • Immunohistochemistry
  • Male
  • Mitochondria, Heart / metabolism
  • Oxygen Inhalation Therapy / methods*
  • Rats
  • Rats, Sprague-Dawley
  • Time Factors
  • Tyrosine / analogs & derivatives
  • Tyrosine / analysis


  • 3-nitrotyrosine
  • Tyrosine