Effects of mild hypothermia on low cardiac output after cardiac surgery

Abstract

To evaluate the effectiveness of mild hypothermia on low cardiac output in patients after cardiac surgery. Twelve patients manifesting low cardiac output after cardiac surgery despite of the use of massive doses of catecholamine and intra-aortic balloon pump (IABP) underwent mild hypothermia during May 2009 to February 2011. Changes in hemodynamic parameters of the patients were measured, including cardiac index (CI),mixed venous oxygen saturation [SvO(2)] and urine volume. In the process of mild hypothermia treatment, bladder temperature of patients was lowered to 33-35 centigrade in order to reduce the body oxygen demand. The CI [ml·s(-1)·m(-2)]of patients after mild hypothermia treatment was increased obviously (38.34 ± 5.00 vs. 30.01 ± 5.00), the same as SvO(2) (0.64 ± 0.07 vs. 0.54 ± 0.08) and urine output [ml·kg(-1)·h(-1): 3.0 ± 2.1 vs. 1.5 ± 1.1, all P < 0.05]. However, there was no significant change in heart rate, mean arterial pressure and blood oxygen pressure. Mild hypothermia is an effective and simple procedure to improve the cardiac function in patients after cardiac surgery complicated with low cardiac output.