Determination of oxygen dosage effects on cytochrome oxidase after anoxia in brain.

Recent evidence reports that high doses of O(2) administered via hyperbaric oxygen therapy (HBOT) improve the return of spontaneous circulation (ROSC), and the outcome of damage to the heart following a 25 min normothermic cardiac arrest. However, excessive O(2) during HBOT can be toxic. Near infrared absorbance spectroscopy (NIRS) measures and determines when cytochrome oxidase (aa(3)), the O(2) end user, changes from reduced to oxidized, signifying adequate dosage.

Hyperbaric oxygen improves rate of return of spontaneous circulation after prolonged normothermic porcine cardiopulmonary arrest.

Aim: This controlled, prospective, randomized porcine study tests the hypothesis that high-dose hyperbaric oxygen (HDHBO2) compared with normobaric oxygen (NBO2) or standard-dose hyperbaric oxygen (SDHBO2), improves return of sustained spontaneous circulation (ROSC) after a normothermic, normobaric, 25-min, non-intervened-upon cardiopulmonary arrest. The study incorporated a direct mechanical ventricular assist device (DMVAD) for open chest continuous cardiac compressions (OCCC) to assist advanced cardiac life support (ACLS). The experiment demonstrates a dose response to oxygen concentration in the breathing mix used in resuscitative ventilation.