Novel thermoregulation system for enhancing cardiac function and hemodynamics during coronary artery bypass graft surgery

Background. Myocardial ischemia, arrhythmias, and coagulopathies are associ ated with postoperative hypothermia. This study assessed the efficacy of a novel thermoregulation system in alleviating these events during coronary a rtery bypass graft (CABG) surgery. Methods. Elective CABG surgery patients were randomized into either Allon t hermoregulation (AT, n = 40) or routine thermal care (RTC, n = 20) groups i n whom the maintenance of normothermia during the nonbypass phases of the o peration was compared. The AT used patients' rectal temperature as referenc e data to monitor the maintenance of the water temperature circulating at 3 7 degreesC in a garment. Rectal temperature, patient hemodynamics, and card iac-specific troponin I (cTnI) levels were assessed at the induction of ane sthesia, 30 minutes into surgery, at discontinuation of bypass, end of surg ery, and 2 hours postoperatively. Results. Body temperature was higher in the AT group compared to the RTC gr oup at all five time points. Cardiac index (CI) (L/min) was higher in the A T group, 2.5 +/- 0.5, 2.6 +/- 0.5*, 3.2 +/- 0.6, 3.3 +/- 0.5*, 3.1 +/- 0.7 at the respective time points, compared to the RTC group, 2.3 +/- 0.6, 2.1 +/- 0.2, 2.6 +/- 0.7, 2.7 +/- 0.7, 2.7 +/- 0.7 (*p < 0.05). Systemic vascul ar resistance (SVR) (dyne . s)/cm(5)) was consistently lower in the AT pati ents. Enzyme levels were elevated in both groups but were less so in the AT patients. Conclusions. The AT system can efficiently maintain normothermia. The benef icial effects are expressed by reduced SVR, elevated Cl, and lower levels o f cTnI, which may show a possible attenuation of myocardial injury. (C) 200 1 by The Society of Thoracic Surgeons.