Does pulsatile flow improve perfusion during hypothermic cardiopulmonary bypass?

Each of 10 patients undergoing hypothermic cardiopulmonary bypass was perfused in turn with (1) the standard flow delivered by a roller pump and (2) pulsatile flow induced by a "pulsatile assist device" (Datascope Corp., Paramus, N. J), presented in random order at the same mean flow. Whole-body oxygen consumption, blood lactate concentration, systemic vascular resistance, urinary flow, and thermal gradients were measured during each type of flow and after rewarming. No significant difference in any of these variables was seen between the two types of flow. After conventional rewarming the temperature gradient between core tissues and muscle was not influenced by the type of flow used during rewarming.