Normothermia is protective during infrarenal aortic surgery

Area of Science:

• Cardiovascular Surgery
• Anesthesiology
• Critical Care Medicine

Background:

• Mild hypothermia's protective role in aortic operations is debated.
• Detrimental cardiac effects of hypothermia have been documented in various surgical procedures.
• Warming methods and hypothermia's impact on aortic surgery require assessment.

Purpose of the Study:

• To assess the influence of different warming methods on patient temperature during aortic operations.
• To evaluate the impact of hypothermia on cardiac outcomes in patients undergoing infrarenal aortic procedures.
• To compare the efficacy of forced air warming blankets versus circulating water mattresses.

Main Methods:

• 100 patients undergoing infrarenal aortic aneurysm or aortoiliac occlusive disease repair were randomized.
• Patients received either a circulating water mattress or a forced air warming blanket.
• 48-hour Holter monitoring was used to assess cardiac events, with cardiologists blinded to treatment.

Main Results:

• Forced air warming maintained significantly warmer core temperatures compared to water mattresses (P <.001).
• The water mattress group experienced more metabolic acidosis (P =.03).
• Hypothermic aneurysm patients (temperature < 36°C) showed decreased cardiac output, thrombocytopenia, elevated prothrombin time, and more cardiac arrhythmias on Holter monitoring.

Conclusions:

• Normothermia is protective for infrarenal aortic surgical patients.
• Forced air warming blankets provide superior temperature maintenance compared to circulating water mattresses.
• Maintaining normothermia improves the clinical profile and reduces cardiac events in aneurysm patients.