Coronary Perfusion Pressure During Cardiopulmonary Resuscitation After Spinal Anesthesia in Dogs

Abstract

Comment This is a well-done study that nicely demonstrates physiologic results that should be intuitive from the known effects of spinal anesthesia. However, this is the first experimental model to have actually demonstrated the expected results. From a scientific point of view, it is unfortunate that the investigators did not measure other data, such as cardiac output, as well as myocardial and cerebral blood flows, to provide a total picture of the effects of spinal anesthesia on closed-chest cardiopulmonary resuscitation. It is particularly concerning that they did not attempt to defibrillate their animals and demonstrate that, indeed, there was a lower incidence of immediate resuscitation in the animals with the very low coronary perfusion pressures. This could have proved their hypothesis that the very low perfusion pressures in the spinal animals would have prevented successful resuscitation. Unfortunately, without the final step, we have to assume that the physiologic data are the same in this model as they would be in other models. This may or may not be the case, and a true outcome study in this model should be done. In the meantime, the lesson from the physiology is that a higher than usual dose of epinephrine may be needed to obtain an adequate perfusion pressure during cardiopulmonary resuscitation in patients having spinal anesthesia.