The Optimal Weaning Strategy for Intraaortic Balloon Counterpulsation: Volume-Based Versus Rate-Based Approach in an Animal Model

Background. Changes in hemodynamics, coronary circulation, visceral flow, and biochemical marker rate reduction or volume deflation for intraaortic balloon pump discontinuation were assessed. Methods. Twelve healthy pigs were randomly assigned to two groups, the rate-based (RB, n = 6) and volume-based weaning groups (VB, n = 6). Hemodynamics and visceral and coronary flows were measured at baseline after 2 hours of intraaortic balloon pump 1:1, during the first 5 hours of weaning (frequency rate reduced to 1:2 in the RB group and volume decreased by 10%/h in the VB group), after 1 hour of frequency rate 1:3 in the RB group or a volume decrease by 75% in the VB group, 2 hours after withdrawal, and 4 hours after withdrawal. Results. The animals weaned by progressive VB deflation showed a greater degree of vasodilation, better cardiac output and stroke volume, fewer negative values of cardiac cycle efficiency, and higher dP/dT(max) compared with those weaned by RB reduction (p <0.05 for all). The VB group also exhibited increased coronary flow, lower oxygen consumption of the myocardium, and coronary resistance during VB weaning (p <0.05 for all). The serum lactate level was lower in the VB group at each experimental point (p <0.05 for all), but visceral flows were scarcely affected by the weaning method. Conclusions. Volume reduction was the most effective weaning method considering that frequency reduction weaning was responsible for significant negative effects on hemodynamics and coronary circulation.