Is a pulse absolutely necessary during cardiopulmonary bypass?

INTRODUCTION: The benefits and disadvantages of pulsatility in mechanical circulatory support devices have been argued since before the first use of cardiopulmonary bypass (CPB) with a nonpulsatile pump. The debate over the superiority of either pulsatile or nonpulsatile perfusion during CPB persists, but recently, the evidence in favor of pulsatile perfusion during CPB is increasing. Complications associated with chronic nonpulsatile flow in patients implanted with left ventricular assist devices have renewed interest in generating pulsatility with these devices. Areas covered: Here we review the definition of pulsatility, the outcomes of CPB using pulsatile and nonpulsatile pumps, and how best to produce and assess pulsatility. This information was identified through online databases and direct extraction of single studies cited in previously identified reports. Expert commentary: The newer generation of biocompatible pulsatile pumps that can generate physiologic pulsation may prove beneficial during temporary support for short-term use during CPB or intermediate support for cardiogenic shock.