Your next patient is a 65-year-old man with hypertension undergoing a laparoscopic ventral hernia repair. You warm him in the preoperative area and actively maintain his core temperature at 37°C intraoperatively. According to a recent study, compared to a similar patient who receives routine thermal management with a core temperature maintained at 35.5°C, which of the following outcomes is MOST likely in your patient within 30 days?
- □ (A) Less need for transfusion
- □ (B) Similar risk of myocardial injury
- □ (C) Lower risk of surgical site infection
The authors enrolled patients from 12 sites in China and one in Ohio. Eligibility included noncardiac surgery with general anesthesia for a duration of two to six hours, presence of at least one cardiac risk factor, a minimum one-night stay postoperatively, and availability of half the anterior body surface to warm. Exclusion criteria included patients with a body mass index greater than 30 kg/m2 and those on dialysis. Patients were randomly assigned to one of two groups. In the routine care group, patients were not prewarmed (ambient room temperature of 20°C), and warming only occurred when body temperature dropped below 35.5°C. In the aggressive warming group, patients received full-body warming 30 minutes before induction of anesthesia, and their body temperature was maintained above 37°C. The study’s primary outcome was a composite of myocardial injury (elevated troponin I), nonfatal cardiac arrest, and all-cause mortality within 30 days of surgery. Secondary outcomes were surgical site infection, intraoperative transfusion requirement, hospital length of stay, and 30-day hospital readmission.
A total of 5,013 patients were included in the data analysis (n = 2,506 in the routine care group; n = 2,507 in the aggressive warming group). The occurrence of at least one of the primary outcome components (myocardial injury, cardiac arrest, or mortality) was similar between the two groups (9.9% in the aggressive warming group vs. 9.6% in the routine warming group). Myocardial injury occurred in 9.4% of patients in the aggressive warming group compared to 9.0% in the routine warming group. Transfusion requirements were similar between the two groups (10% in the aggressive warming group compared to 9.5% in the routine warming group). The study found there was no difference in surgical site infections, which occurred in 7.2% of patients in the aggressive warming group and 6.3% of patients in the routine warming group.
In summary, no substantial outcome differences were found between patients who received aggressive warming and those who received routine warming in this large cohort of patients with tightly controlled body temperatures. Patients had similar instances of surgical site infection, all-cause mortality, cardiac injury, and nonfatal cardiac arrest within 30 days of surgery, and similar transfusion requirements.