NO-REFLOW AFTER CARDIAC-ARREST

Objective: Successful resuscitation of the brain requires unimpaired blood recirculation. The study addresses the question of the severity and reversibility of no-reflow after cardiac arrest. Design: Adult normothermic cats were submitted to 5, 15 and 30 min cardiac arrest by ventricular fibrillation. The extent of no-reflow was assessed in each cardiac arrest group after 5 min closed chest cardiac massage in combination with 0.2 mg/kg epinephrine or after successful resuscitation followed by 30 min recirculation. Measurements and results: Reperfusion of the brain was visualized by labelling the circulating blood with FITC-Albumin. Areas of no-reflow, defined as absence of microvascular filling, were identified by fluorescence microscopy at 8 standard coronal levels of forebrain, and expressed as percent of total sectional area. During cardiac massage, no-reflow affected 21 +/- 5%, 42 +/- 38% and 70 +/- 27% of forebrain after 5, 15 and 30 min cardiac arrest, respectively. After 30 min spontaneous recirculation following successful resuscitation of the heart, no-reflow significantly declined to 7 +/- 11% after 5 min cardiac arrest (p < 0.05) but persisted in 30 +/- 11% and 65 +/- 21% of forebrain after 15 and 30 min cardiac arrest, respectively (n.s.). Conclusion: Our observations demonstrate that resuscitation of the heart by closed chest massage causes severe (and after prolonged cardiac arrest irreversible) no-reflow of the brain. This suggests that no-reflow is an important cause of postresuscitation brain pathology.