Effect of warm heart surgery on perioperative management of patients undergoing urgent cardiac surgery

Abstract

The anesthetic management and outcome data were examined in a retrospective case-controlled study that compared a conventional hypothermic cardioplegic technique with the recently described method of warm heart surgery, in patients undergoing urgent cardiac surgery. Hypothermic continuous oxygenated blood crystalloid cardioplegia with systemic hypothermia was used for 37 patients who underwent cardiac surgery by the same surgeon over a 16-month period from July 1986 (group 1), whereas normothermic continuous oxygenated blood crystalloid cardioplegia with systemic normothermia was used on 56 patients over the following 16-month period until March 1990 (group 2). The groups were similar in terms of age, sex, ASA status, NYHA classification, and preoperative left ventricular function. Defibrillation following cardiopulmonary bypass was required in only 3.6% of the warm heart surgery patients (group 2) compared with 83.8% in group 1 ( P < 0.0001), and use of warm heart surgery (group 2) eliminated the need for rewarming. There was a trend towards a reduced incidence of myocardial infarction (19% in group 1 vs 9% in group 2), low cardiac output syndrome (40% vs 29%), and use of the intraaortic balloon pump (16% vs 9%) in warm heart surgery patients, but these differences did not reach statistical significance. There were no differences between the two groups in terms of anesthetic drug usage, total heparin or protamine doses, blood loss, transfusion requirements, or duration of ICU stay. These results suggest that: (1) hypothermia is not an absolute requirement for myocardial protection; (2) warm cardioplegia is a useful and safe technique in high-risk patients undergoing urgent cardiac surgery; (3) warm cardioplegia is associated with a reduced requirement for postbypass defibrillation; and (4) introduction into clinical practice of warm heart surgery resulted in no significant changes in perioperative management of patients undergoing urgent cardiac surgery.