Study: Procedural sedation causes heat loss on par with general anesthesia in endoscopy patients

Editor's Note

Research shows patients undergoing procedural sedation for endoscopic procedures experience significant and often undetected heat loss comparable to that seen during general anesthesia despite widespread assumptions that sedation preserves thermoregulation. Findings were published May 27 in The Journal of PeriAnesthesia Nursing.  

Conducted at a tertiary hospital in Queensland, Australia, the prospective, descriptive study used continuous temperature monitoring via zero-heat-flux sensors placed on the foreheads of 165 adults undergoing outpatient complex upper or lower endoscopy between July 2022 and July 2023. Procedural sedation was propofol, often in combination with opioids or benzodiazepines. Temperature data were recorded at multiple timepoints from induction through recovery. Clinical data—including shivering and thermal comfort—were also collected, along with patient satisfaction surveys the following day.

Key findings include:

• Core body temperature declined by an average of 0.19°C every 15 minutes of sedation (95% CI: −0.18 to −0.21).
• Mean body temperature dropped below 36°C at 45 minutes.
• By the time patients reached recovery:
  • 30% were hypothermic on arrival to first-stage recovery.
  • 42% were hypothermic on arrival to second-stage recovery.
• Shivering was observed postprocedure in 5% of patients.
• Thermal comfort scores declined postprocedure, indicating mild cold discomfort.

Sedation-induced heat loss followed a similar pattern to the redistribution hypothermia seen during general anesthesia, researchers write, attributing the effect to vasodilation and heat transfer from the core to periphery. Although sedation involves lower drug doses, the lack of routine warming and temperature monitoring leaves patients vulnerable to avoidable hypothermia and its consequences, including discomfort, delayed recovery, and possible increased infection risk.

The authors recommend that continuous temperature monitoring be adopted during procedural sedation—a practice not specified in standard guidelines for sedation—and that facilities consider active warming measures, ambient temperature adjustments, and strategies to minimize body exposure.