Preoperative Patient Warming for Prevention of Perioperative Hypothermia in Major Abdominal Surgery

Study Overview
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Brief Summary
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The study should evaluate how long patients undergoing major abdominal surgery under combined general/epidural anaesthesia have to be actively warmed preoperatively to prevent perioperative hypothermia and postoperative shivering. 99 patients will receive forced-air skin-surface warming for different duration. Body temperature will be measured at the tympanic membrane. The investigators hypothesize that active warming before starting the epidural anaesthesia will decrease the incidence of perioperative hypothermia.

Detailed Description
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The aim of our study is to evaluate the performance of different durations of active preoperative skin-surface warming (prewarming) to prevent perioperative hypothermia in patients undergoing major abdominal surgery under combined general/epidural anaesthesia. The investigators plan to enroll 99 patients in 3 groups. Body temperature will be measured at the tympanic membrane. The investigators hypothesize that active warming before starting the epidural anaesthesia will decrease the incidence of perioperative hypothermia.

Official Title
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The Effect of Preoperative Patient Warming in the Prevention of Perioperative Hypothermia in Major Abdominal Surgery Under Combined General/Epidural Anaesthesia

Conditions
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Preoperative Warming, Prewarming, Perioperative Hypothermia, General Anaesthesia, Epidural Anaesthesia, Temperature Monitoring

Intervention / Treatment
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* Device: Forced-air warming


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: age over 18 years planned duration of surgery > 2 hours planned for elective major abdominal surgery under combined epidural/general anaesthesia written informed consent American society of anesthesiologists status 1-3 Exclusion Criteria: duration of surgery < 90 min withdrawal of consent emergency surgery

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Group 2, Prewarming only before general anaesthesia<br>Active forced-air warming for 15 min after completion of epidural anaesthesia / before start of general anaesthesia. Continued active forced-air warming after induction of general anaesthesia until operation is finished (intraoperatively). Application of warmed infusions (41 °C). | Device: Forced-air warming<br>* In the intervention groups a forced-air cover (Level 1 Snuggle Warm Upper Body Blanket, Smiths Medicals) will be positioned over the patients sitting or laying on the operating table for 15 min before start of epidural anaesthesia and afterwards till start of general anaesthesia (group 3), for 15 min before start of general anaesthesia (group 2) or only after induction of general anaesthesia (group 1, control). All patients will receive forced-air warming after induction of general anaesthesia till end of surgery.<br>* Other names: Forced-air warming blower;|
| Experimental: Group 3, Prewarming before epidural and general anaesthesia<br>Active forced-air warming for 15 min before start of epidural anaesthesia and for 15 min after completion of epidural anaesthesia / before start of general anaesthesia. Continued active forced-air warming after induction of general anaesthesia until operation is finished (intraoperatively). Application of warmed infusions (41 °C). | Device: Forced-air warming<br>* In the intervention groups a forced-air cover (Level 1 Snuggle Warm Upper Body Blanket, Smiths Medicals) will be positioned over the patients sitting or laying on the operating table for 15 min before start of epidural anaesthesia and afterwards till start of general anaesthesia (group 3), for 15 min before start of general anaesthesia (group 2) or only after induction of general anaesthesia (group 1, control). All patients will receive forced-air warming after induction of general anaesthesia till end of surgery.<br>* Other names: Forced-air warming blower;|
| No Intervention: Group 1, control group<br>No active warming before start of epidural or general anaesthesia, active forced-air warming after induction of general anaesthesia until operation is finished (intraoperatively). Application of warmed infusions (41 °C). | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence of hypothermic patients at arrival at PACU | After the operation patients will be admitted to the PACU. Here, body temperature will be assessed and the incidence of hypothermic patients (body temperature < 36°C)will be measured. | 2 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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epidural anaesthesia, temperature measurement, perioperative hypothermia, prewarming, preoperative warming, general anaesthesia