The effect of skin surface warming on pre-operative anxiety in neurosurgery patients

Skin surface warming of patients not only improves thermal comfort, but has been shown to reduce anxiety in a pre-hospital setting. We tested the hypothesis that pre-operative warming can reduce pre-operative anxiety as effectively as a conventional dose of intravenous midazolam in patients undergoing neurosurgery. We randomly allocated 80 patients to four groups in the pre-operative holding area. Treatment was applied for 30-45 min with (1) passive insulation and placebo; (2) passive insulation and intravenous midazolam (30 mu g.kg(-1)); (3) warming with forced-air and placebo; and (4) warming with forced-air and intravenous midazolam (30 mu g.kg(-1)). Thermal comfort levels (VAS 0-100 mm) and anxiety levels (VAS 0-100 mm, Spielberger State-Trait Anxiety Inventory) were assessed twice: before the designated treatment was started and before induction of anaesthesia. In the midazolam and the midazolam/warming groups, anxiety VAS and Spielberger state anxiety scores decreased by - 19 (95% CI: - 29 to - 9, p < 0.01) and - 10 (95% CI: - 14 to - 6, p < 0.01), respectively. In the warming and the combined groups, thermal VAS increased by + 26 (95% CI: 17-34, p < 0.01). Pre-operative warming did not reduce anxiety VAS (p = 0.11) or Spielberger state anxiety (p = 0.19). The results of our study indicate that pre-operative warming can be recommended solely to improve thermal comfort, not to replace anxiolytic premedication regimens.