Evidence Based Practice and Quality Assurance
Background and Goal of Study: Active warming of patients is not only able to improve thermal comfort, but has also been shown to reduce anxiety in a prehospital setting (1). We compared the efficacy of active warming with forced air in the preoperative holding area with passive insulation and/or midazolam.
Materials and Methods: 80 patients were randomized in 4 groups in the preoperative holding area:
- passive insulation and placebo;
- passive insulation and midazolam (30 μg/kg);
- active warming with forced air and placebo;
- active warming with forced air and midazolam (30 μg/kg).
After an initial set of measurements the designated treatment was instituted, a second set of measurements was performed in the OR, right before induction of anesthesia (30-45 min later). Thermal comfort and anxiety levels were assessed with VAS 0-100 (0 intense cold/no anxiety; 100 intense heat/severe anxiety) and patients' anxiety was additionally measured with the Spielberger State-Trait Anxiety Inventory (STAI).
Results and Discussions:
- Prewarming with forced air provides better thermal comfort in the preoperative area.
- It does not reduce preoperative anxiety adequately in comparison to midazolam.
- A combination of prewarming and midazolam can be recommended.