Perioperative Hypothermia and Myocardial Injury After Non-cardiac Surgery (PROTECT)

NeuroTherapia, Inc.

Status: Completed

Conditions: Perioperative Care; Hypothermia; Anesthesia; Surgery--Complications; Myocardial Injury

Treatments: Device: routine thermal management; Device: aggressive warming

Study type: Interventional

Funder types: Other

Identifiers

NCT03111875

16-1017

Details and patient eligibility

About

We propose to test the hypothesis that aggressive warming reduces the incidence of major cardiovascular complications, compared to routine care. Half of the participants will be randomly assigned to routine care (core temperature ≈35.5°C), while the other half will receive aggressive warming (>37°C core temperature) in a multi-center trial.

Full description

Hypothermia increases sympathetic activation, promotes tachycardia, and causes hypertension - all of which may increase the risk of myocardial injury. Moderate perioperative hypothermia is now uncommon, but mild hyperthermia (≈35.5°C) remains common. Whether aggressive warming to a truly normothermic level (≈37°C) improves outcomes remains unknown.

Enrollment: 5,056 patients

Sex: All

Ages: 45+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Scheduled for major noncardiac surgery expected to last 2-6 hours;

• Having general anesthesia;

• Expected to require at least overnight hospitalization;

• Expected to have >50% of the anterior skin surface available for warming;

• Have at least one of the following risk factors:

  a. Age over 65 years; b. History of peripheral vascular surgery; c. History of coronary artery disease; d. History of stroke or transient ischemic attack; e. Serum creatinine >175 µmal/L (>2.0 mg/dl); f. Diabetes requiring medication; e. Hypertension requiring medication; g. Current smoking.

Exclusion criteria

• Have a clinically important coagulopathy in the judgement of the attending anesthesiologist;
• Are septic (clinical diagnosis by the attending anesthesiologist);
• Body mass index exceeding 30 kg/m2;
• End-stage renal disease requiring dialysis;
• Surgeon believes patient to be at particular infection risk.

Trial design

Primary purpose: Supportive Care

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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5,056 participants in 2 patient groups

Routine thermal management

Active Comparator group

Description:

Patients assigned to routine thermal management will not be pre-warmed and ambient intraoperative temperature will be maintained near 20°C per routine. Only transfused blood will be warmed. An Multi-Position Upper Body Warming Blanket forced-air cover will be positioned over an appropriate non-operative site, but will not initially be activated. Should core temperature decrease to 35.5°C, the warmer will be activated as necessary to prevent core temperature from decreasing further.

Treatment:

Device: routine thermal management

Aggressive thermal management

Experimental group

Description:

Patients assigned to aggressive warming will be pre-warmed with a full-body Bair Hugger or Bair Paws cover for ≈30 minutes before induction of anesthesia. The warmer will initially be set to "high" which corresponds to ≈43°C. It will be subsequently adjusted to make patients feel warm, but not uncomfortably so. Patients will be aggressively warmed during surgery to a target intraoperative core temperature between 37 and 37.5°C, using an Multi-Position Upper Body and Full Access Underbody Warming Blankets forced-air covers when clinically practical. All intravenous fluids will be warmed to body temperature.

Treatment:

Device: aggressive warming