Author: Eric Ramos
The addition of a heated humidified breathing circuit (HHBC) to standard forced air warming blankets in hypothermic patients admitted to the intensive care unit (ICU) after cardiac surgery did not result in a statistically significant reduction in time to normothermia, according to a study presented at the 2020 Virtual Meeting of the American Society of Anesthesiologists (ASA).
“Unfortunately, this study did not show any statistically significant benefit of adding a heated humidified breathing circuit to the standard forced air warming blanket, although this study may have been underpowered, and time to normothermia was numerically reduced with the addition of the humidified breathing circuit,” said Benjamin Brockbank, MD, Duke University Medical Center, Durham, North Carolina.
Between April 1, 2019, and June 15, 2019, 14 hypothermic (≤35 degrees Celsius) patients who were admitted to the ICU after undergoing cardiac surgery with cardiopulmonary bypass received active warming via forced air heating blankets, set at 42 degrees Celsius, with the addition of warming through HHBC using the ANAPOD Humi-Therm Heated Humidification System. Patients were matched (for age, sex, race, and type of procedure) with 28 patients who underwent similar surgeries within 2 years prior to initiation of the trial, and received only standard forced air warming blankets.
Exclusion criteria included patients placed on extracorporeal membrane oxygenation intraoperatively or during the first 24 hours after ICU admission, and patients who had any additional surgical procedures in the first 24 hours after initial surgery.
The time to normothermia — the primary outcome — in the control group was 4.8 hours versus 4.4 hours for the group receiving additional warming with HHBC (P = .262).
There was no difference between groups in time to extubation, time to normal PH, ICU blood product transfusion, and laboratory coagulation profile in the ICU.
“I think [this study] opens up the door for future trials where a larger patient population with tighter timeframes may be able to show a difference in the addition of adding a heated humidified breathing circuit to the forced air warming blanket,” noted Dr. Brockbank.