We are surprised that Persson and Lundberg obtained ethical approval for a study in which a group of patients was allowed to develop perioperative hypothermia . Hypothermia prolongs recovery , increases perioperative bleeding , compromises wound healing, and increases the risk of wound infection  and cardiac complications . Persson and Lundberg themselves referred to most of these problems.
The Declaration of Helsinki states that the importance of the objective of the research should outweigh the inherent risks and burdens to the subject . It is difficult to see how exposing patients to the risks of hypothermia is in proportion to asking whether patients require more or less opioid analgesia. The evidence that hypothermia is harmful is compelling, and hypothermia can be avoided by simple routine measures. It is now time to accept that allowing patients to become hypothermic is, at best, inappropriate and, at worst, bad practice, and we believe that Persson and Lundberg's study was unethical.
M. G. Booth
Department of Anaesthesia; Royal Infirmary; Glasgow, UK
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