Hypothermia for the Management of Low Cardiac Output Syndrome after Open Heart Surgery / 日本心臓血管外科学会雑誌

ABSTRACT

Surface induced hypothermia was introduced in six cases with low cardiac output syndrome after open heart surgery to reduce oxgen consumption. The patients were consisted of two ACBG, two LV rupture after MVR, MVR with ACBG and AVR with poor LV function. Hemodynamic changes such as heart rate, mean arterial pressure, cardiac index, systemic vascular resistance, pulmonary artery wedge pressure, were measured every 3-4 hours throughout the course of hypothermia. Acid-base balance, mixed venous oxgen saturation and oxygen consumption were also monitored. Hypothermia was induced using a blanket and ice-beutels. Temperature in hypothermia was maintained at about 33°C. We are intended to increase SVO₂ up to the level of 50% and to improve anerobic condition. Hypothermia was continued for 45 hours in the shortest and 148 hours in the longest case with a mean of 78 hours. Arrythmia was not seen. Hemodynamic and acid-base balance were in significantly changed in comparison of the control values. However, SVO₂ and VO₂ changed significantly after introduction of hypothermia. They increased from 47.8±7.5% to 58.7±7.9% and reduced from 231±29.7 to 188±31.3ml O₂/min respectively. Hemodynamic condition was improved and IABP was successfully weaned in all cases. We suggest that the use of hypothermia is one of the effective modality in the management of low cardiac output syndrome after open heart surgery.