Cardiovascular function and neurologic outcome after cardiac arrest in dogs. The cardiovascular post-resuscitation syndrome

We studied cardiovascular changes and neurologic outcome at 72 h in 42 healthy dogs after normothermic ventricular fibrillation cardiac arrest (no blood flow) of 7.5, 10, or 12.5 min duration, reversed by standard external cardiopulmonary resuscitation (CPR) (≤ 10 min) and followed by controlled ventilation to 20 h and intensive care to 72 h. We found no difference in resuscitability, mortality, neurologic deficit scores, or overall performance categories between the three insult groups. There was no major pulmonary dysfunction. During controlled normotension post-CPR, all dogs presented a transient reduction in cardiac output. In the 12.5-min cardiac arrest group the decrease in cardiac output persisted beyond 12 h post-CPR (P < 0.01) and was associated with more severe arrhythmias (P < 0.05) and worse morphologic myocardial damage (P < 0.01). Both cardiac and neurologic malfunction at 72 h correlated with arrest time. Only cardiac malfunction correlated with CPR time. Neurologic recovery correlated with mild (inadvertent) pre-arrest hypothermia, diastolic arterial pressure during CPR and absence of cardiovascular impairment at 12 h post-CPR. We conclude that prolonged cardiac arrest in previously healthy dogs is followed by persistent cardiovascular derangements that correlate with impaired neurologic recovery

Emergency cardiopulmonary bypass for resuscitation from prolonged cardiac arrest

After cardiac arrest (no flow) of more than approximately 5 minutes' duration, standard external cardiopulmonary resuscitation (CPR) basic, advanced, and prolonged life support (BLS, ALS, PLS) do not reliably produce cerebral and coronary perfusion pressures to maintain viability and achieve stable spontaneous normotension; nor do they provide prolonged control over pressure, flow, composition, and temperature of blood. Since these capabilities are often needed to achieve conscious survival, emergency closed-chest cardiopulmonary bypass (CPB) by veno-arterial pumping via oxygenator is presented in this review as a potential addition to ALS-PLS for selected cases. In six dog studies by the Pittsburgh group (n = 211; 1982 through 1988), all 179 dogs that received CPB after prolonged cardiac arrest (no flow) or after CPR (low flow) states had restoration of stable spontaneous circulation. The use of CPB enhanced survival and neurological recovery over those achieved with CPR-ALS attempts only. With CPB and standard intensive care, it was possible to reverse normothermic ventricular fibrillation (VF) cardiac arrest (no flow) of up to 15 minutes and to achieve survival without neurologic deficit; VF of 20 minutes to achieve survival but with neurologic deficit; and VF of 30 minutes to achieve transient restoration of spontaneous circulation followed by secondary cardiac death. CPB could restore stable spontaneous circulation after ice water submersion of up to 90 minutes. Other groups' laboratory and clinical results agree with these findings in general. Clinical feasibility trials are needed to work out logistic problems and to meet clinical challenges. Future possibilities for emergency CPB require further research and development