Effects of Active Prewarming in Perioperative Hypothermia in Adults

Study Overview
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Brief Summary
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This study evaluates the effect of active prewarming on the frequency and duration of perioperative hypothermia. 50% of patients will receive active warming with forced-air devices prior to entering the operating room, and the other 50% will not receive any active heating measures.

Detailed Description
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Inadvertent perioperative hypothermia is defined as a body temperature below 36º C during the perioperative period. It occurs as a result of the effects of anesthetic drugs on the regulation of body temperature and exposure to a cold environment. The main temperature loss during the perioperative period occurs during the first hour after the anesthetic induction as a result of heat redistribution from the central compartment to the peripheral compartment The most effective strategy to prevent perioperative hypothermia is the use of forced-air warming devices. These devices are usually initiated once the patient enters the operating room. At that time, the patient has already initiated the heat loss by distributing heat from the central to the peripheral compartment to maintain body temperature. We intend to use forced-air warming devices before the patients is transferred to the operating room in order to preserve the peripheral body temperature. This way the redistribution of heat should be avoided and, therefore, perioperative hypothermia and its harmful effects will be prevented.

Official Title
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Effect of Active Warming Prior to Surgery in Perioperative Hypothermia

Conditions
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Hypothermia; Anesthesia, Hypothermia Due to Anesthetic, Hypothermia Following Anesthesia, Hypothermia Following Anesthesia, Sequela

Intervention / Treatment
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* Device: Forced air warming devices


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: > 18 years old. American Society of Anesthesiologists I-III. Undergoing surgery under general or locoregional anesthesia lasting more than 30 minutes. General surgery: hernias, cholecystectomies, hepatectomies, intestinal resections, pancreatoduodenectomies ... Traumatology and orthopedics: total / partial knee prosthesis, total / partial hip prosthesis, osteosynthesis, removal of material, arthroscopies, hallux valgus, lumbar arthrodesis ... Neurosurgery: lumbar arthrodesis, excision of intracranial tumors. Gynecology: Hysterectomies, adnexectomies, hysteroscopy ... Otorhinolaryngology: septoplasty, nasosinusal endoscopic surgery, tonsillectomies, adenoidectomies, thyroidectomies... Thoracic: Pneumonectomies and pulmonary resections, sympathectomies, thoracoscopy ... Urology: Bladder transurethral resection , prostate transurethral resection, nephrectomies. Maxillofacial: parathyroidectomies, microsurgery ... Ability to understand the study, give authorization and collaborate with data collection Exclusion Criteria: Local anesthesia or peripheral nerve block. Urgent or emergent surgery. Cognitive impairment or lack of collaboration of any kind Pregnant women undergoing cesarean section. Diabetes Mellitus poorly controlled (HbA1c> 6.5-7%) Subjects that are under treatment with drugs that interfere with thermoregulation or may cause drug-induced hyperthermia (amphetamines, barbiturates, inhaled gases ...) Subjects with burns, pressure ulcers and other surface disturbances that cover the heating devices Subjects with screening temperature > 37.5º C. Subjects with fever or active infections. Subjects with chronic anemia who require periodic transfusions

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: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Prewarming<br>Active warming is allowed prior to surgery with forced-air warming devices | Device: Forced air warming devices<br>* In the treatment group, heating will be started with a pre-surgical forced-air blanket Outpatient Warming Blanket model 11101 Bair Hugger from 3M and a forced-air heating unit Bair Hugger Warming Unit Model 775 from 3M at 38-43º C which will be maintain during the stay in the pre-surgery room until the transfer to the operating room<br>* Other names: BAir Hugger Warming Unit Model 775 3M;|
| No Intervention: No prewarming<br>Non active warming is allowed before surgery | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Perioperative hypothermia | Core temperature below 36º C measured with 3M Spot On monitor every 5 minutes from arrival to the pre-surgical area, during surgery and unit discharge to the ward | From 1 hour to 12 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Hypothermia duration | Time of core temperature below 36º C measured every 5 minutes with 3M Spot On monitor from arrival to the surgery room and unit discharge to postoperative unit. | Minutes with core temperature below 36ºC from arrival to the OR unit discharge to postoperative unit, up to 10 hours, whichever came first. | 
| Hospital stay | Patient´s days keep in hospital, from admission in hospital until discharge from the home | From date of Admission in hospital until the date of discharge from hospital, assessed up to 120 days. | 
| Surgical site infection | Follow-up the wound and evaluation of signs and symptoms of surgical site infection from surgery to review for the nurse. | 1 Month | 
| Prewarming duration | Time from pre-warming initiation in pre operative area with forced air warming device until transfer to operating theatre. | From 10 minutes to 1 hour | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Active preoperative warming, Inadvertent hypothermia, Perioperative hypothermia, Surgical prewarming, Forced air warming