The effects of pulsatile and non-pulsatile cardiopulmonary bypass on renal blood flow and function

Abstract

The physiologic effects of pulsatile and non-pulsatile flow in cardiopulmonary bypass were compared in terms of the relationship between different flow rates and what effects these had on pulsatile and non-pulsatile flow. Forty adult mongrel dogs were used in this study and divided into 5 groups, each comprised of 8 animals, according to the flow rate during cardiopulmonary bypass, namely; 40, 60, 80, 100, or 120 ml/kg/min. The animals were perfused with either pulsatile or non-pulsatile flow for 1 hour, given randomly at the same mean flow rate. At flow rates of 80 and 100 ml/kg/min, the mean arterial blood pressure and total peripheral vascular resistance were significantly lower in pulsatile flow than in non-pulsatile flow, and the renal blood flow was significantly greater in pulsatile flow than in non-pulsatile flow. The renal arterial-venous lactate difference was significantly less in pulsatile flow than in non-pulsatile flow at a flow rate of 80 ml/kg/min, and the renal lactate extraction was significantly higher in pulsatile flow than in non-pulsatile flow at the same flow rate. The renal excess lactate was significantly lower in pulsatile flow than in non-pulsatile flow at a flow rate of 100 ml/kg/min. There were no significant differences in these parameters between the two types of perfusion at flow rates of 40, 60 or 120 ml/kg/min. Pulsatile flow was therefore apparently advantageous, when compared to non-pulsatile flow, in terms of hemodynamics, renal circulation, and metabolism of the kidney at flow rates of 80 and 100 ml/kg/min. However, when the flow rate was 120 ml/kg/min, pulsatile flow and non-pulsatile flow had the same effects.

Cerebral oxygen saturation during pulsatile and non-pulsatile cardiopulmonary bypass in patients with carotid stenosis

“…Nevertheless, the MAP in the present study was found to be lower during pulsatile flow than during non-pulsatile flow. This is in line with the described findings of Nakamura et al 17 and indicates that, technically, the pulse mode characteristics could be adjusted to ensure a favorable MAP level by, for example, reducing the pulse-cycle base flow or narrowing the pulse width. However, empirically, such alterations have very limited impact on common perfusion parameters.…”

“…10 Our second main finding was that MAP decreased during pulsatile mode compared with non-pulsatile, a phenomenon that has been described by Nakamura et al for clinically relevant CPB flow levels. 17 Similarly, increased MAP has been previously reported by Mandelbaum et al and Giron et al during non-pulsatile CPB flow. 18,19…”

“…10 Our second main finding was that MAP decreased during pulsatile mode compared with non-pulsatile, a phenomenon that has been described by Nakamura et al for clinically relevant CPB flow levels. 17 Similarly, increased MAP has been previously reported by Mandelbaum Murkin et al have presented the beneficial impact of pulsatile CPB flow on the incidence of myocardial infarction, major complications and death 20,21 and more recent papers also demonstrate advantageous effects, such as increased overall cerebral blood flow and cerebral oxygen saturation levels, along with reduced vascular resistance and less plasma free haemoglobin. 22,23 In a review of 159 papers on pulsatile blood flow, Ji et al reported no evidence of adverse effects of pulsatile flow, but several papers described the positive effects on various parameters, such as hormone release, lung function, inflammatory response and perfusion of vital organs.…”

Predictors of renal replacement therapy after heart transplantation and its impact on long‐term survival

“…As previously described, patients on short‐term MCS are at a high a risk of complications, and AKI might occur in as much as 80% of these patients . There are many reasons to explain this association, such as the profound shock that can be present in a patient before the MCS can be installed, or the fact that for a given renal blood flow, the continuous flow compared with the pulsatile flow might increase the risk of renal injury . Though the HT in a patient on short‐term MCS might be the definitive treatment, the multiple aggressions to the kidney during the cardiogenic shock and at the time of HT surgery might lead to severe ischemic damage to the kidney, which ends with the need of RRT.…”

Experimental Investigation of Pulsatility Effect on the Deformability and Hemolysis of Blood Cells

“…It has been reported that pulsatile CPB procedure provides more beneficial effects on organ functions such as microcirculation, myocardial perfusion, and oxygen exchangeability. It also reduces systemic vascular resistance compared with nonpulsatile CPB procedures (1–6). From these advantages of pulsatile perfusion, many researchers propose that pulsatile blood perfusion is better than nonpulsatile perfusion in a physiological and hemodynamic point of view (1–6).…”