Literature Review: Forced-Air Warming vs Passive Blanket Warming to Prevent
Intraoperative Hypothermia and Improve Hemodynamic Stability
PICOT Question
In adult patients undergoing general anesthesia, does forced-air warming before or during
induction compared to passive blanket warming decrease incidence of hypothermia and
improve intraoperative blood pressure stability during intraoperative period through
PACU discharge?
Population: Adult patients undergoing surgery under general anesthesia
Intervention: Forced-air warming before or during induction
Comparator: Passive blanket warming
Outcome: Decrease incidence of hypothermia and improve intraoperative blood pressure
stability
Timeframe: During intraoperative period through PACU discharge
Characteristics of Included Studies (Selected 10 studies)
Yoo JH et al. (2021). Efficacy of active forced-air warming during induction of
anesthesia to prevent inadvertent perioperative hypothermia in intraoperative
warming patients. (Randomized Controlled Trial)
, Purpose: This randomized controlled trial evaluated the effect of peri-induction forced-air
warming (FAW) on the incidence of inadvertent perioperative hypothermia in adult
patients undergoing major surgery. Sample/Setting: Adult patients scheduled for major
surgeries (>120 minutes) at a tertiary academic hospital; sample size approximately 200
randomized to FAW during induction versus passive warming. Methods: Fourth-
generation randomized, non-blinded design comparing core temperature trajectories,
incidence of hypothermia (core temp <36.0°C), and secondary outcomes including
shivering and PACU length of stay. Results: Peri-induction FAW significantly reduced
the incidence of hypothermia on arrival to PACU and maintained higher mean core
temperatures intraoperatively compared with passive blankets. FAW reduced shivering
rates. Conclusions: FAW during induction is effective at reducing perioperative
hypothermia in patients who receive intraoperative warming. Strengths include RCT
design and continuous temperature monitoring; limitations include single-center setting
and lack of blinding. Evidence level: Level II (Randomized Controlled Trial).
Yang H et al. (2024). Effects of different forced-air warming systems on core
temperature (prospective comparative study).
Purpose: Compared different FAW systems and configurations (upper body, lower body,
underbody) and their effects on core temperature maintenance. Sample/Setting: Multi-
arm prospective study across several surgical specialties, n~180. Methods included
standardized anesthesia protocols and temperature monitoring. Results: Underbody and
lower-body FAW provided more consistent preservation of core temperature compared to
Intraoperative Hypothermia and Improve Hemodynamic Stability
PICOT Question
In adult patients undergoing general anesthesia, does forced-air warming before or during
induction compared to passive blanket warming decrease incidence of hypothermia and
improve intraoperative blood pressure stability during intraoperative period through
PACU discharge?
Population: Adult patients undergoing surgery under general anesthesia
Intervention: Forced-air warming before or during induction
Comparator: Passive blanket warming
Outcome: Decrease incidence of hypothermia and improve intraoperative blood pressure
stability
Timeframe: During intraoperative period through PACU discharge
Characteristics of Included Studies (Selected 10 studies)
Yoo JH et al. (2021). Efficacy of active forced-air warming during induction of
anesthesia to prevent inadvertent perioperative hypothermia in intraoperative
warming patients. (Randomized Controlled Trial)
, Purpose: This randomized controlled trial evaluated the effect of peri-induction forced-air
warming (FAW) on the incidence of inadvertent perioperative hypothermia in adult
patients undergoing major surgery. Sample/Setting: Adult patients scheduled for major
surgeries (>120 minutes) at a tertiary academic hospital; sample size approximately 200
randomized to FAW during induction versus passive warming. Methods: Fourth-
generation randomized, non-blinded design comparing core temperature trajectories,
incidence of hypothermia (core temp <36.0°C), and secondary outcomes including
shivering and PACU length of stay. Results: Peri-induction FAW significantly reduced
the incidence of hypothermia on arrival to PACU and maintained higher mean core
temperatures intraoperatively compared with passive blankets. FAW reduced shivering
rates. Conclusions: FAW during induction is effective at reducing perioperative
hypothermia in patients who receive intraoperative warming. Strengths include RCT
design and continuous temperature monitoring; limitations include single-center setting
and lack of blinding. Evidence level: Level II (Randomized Controlled Trial).
Yang H et al. (2024). Effects of different forced-air warming systems on core
temperature (prospective comparative study).
Purpose: Compared different FAW systems and configurations (upper body, lower body,
underbody) and their effects on core temperature maintenance. Sample/Setting: Multi-
arm prospective study across several surgical specialties, n~180. Methods included
standardized anesthesia protocols and temperature monitoring. Results: Underbody and
lower-body FAW provided more consistent preservation of core temperature compared to
