Perioperative Hypothermia Hypothermia in Ambulatory Surgery

Background:

Anesthesia medicaments given in general anesthesia cause impaired thermoregulation and thermogenesis. After induction of general anesthesia the core temperature is reduced to redistribution of blood from the body core to the cooler skin. Later impaired thermogenesis contributes to further loss of heat.

Mild hypothermia (<36 degrees Celsius) contributes to increased incidence of wound infections, prolonged stay in the post anesthesia care unit, shivering and reduced patient comfort.

There are several effective interventions to prevent hypothermia such as active warming pre-, per- and postoperatively. Preheated intravenous fluids and medical interventions to alter the blood distribution from the periphery to the body core have been effective in preventing hypothermia.

In the department both self-warming blanket (Easywarm®) and forced-air blanket (BairHugger®) are routinely used to prevent hypothermia. It has been observed that a few patients undergoing plastic surgery with anesthesia time more than one hour are shivering and feeling cold in the postoperative period.

Purpose:

The purpose of the study is to observe and measure patient- temperature in the perioperative period of patients undergoing plastic surgery in an ambulatory surgical unit. This study will evaluate if active warming with self-warming blanket (Easywarm®) is as effective as active warming with forced-air blanket (BairHugger®). Second the study will evaluate if one or both methods is effective in preventing perioperative hypothermia.

Design:

The is a quality assurance study deigned as a prospective randomised trial. With a validated non-invasive termometer (SpotOn® 3M) temperature is measured before, during and after surgical procedures in general anesthesia. An equal number of notes with the number 1 and 2 were put into an envelope (1=EasyWarm®, 2=BairHugger®). For each operation theater a note is drawn, and all patients in that operation theater receives active warming according to the number on the note.

Population data:

Sex, age , weight, height, BMI, medication, morbidities and ASA class will be registered.

Measurements:

• temperature (Celsius)
• Blood pressure
• Heartrate
• SaO2
• Temperature-comfort "numeric rating scale" (NRS)

Other registrations:

• Medicines given during the study period.
• Start and end of anesthesia and surgery
• Time when temperature is above or eual to 36 degrees Celsius.
• Time when the patient go home

Data is collected and registered on a dataform. Data are analysed in a anonymized excel workbook.

Inclusion criteria

• Patients for planned plastic surgery with duration of general anesthesia ≥ 60 minutes.

Exclusion criteria

• None