An unusual postoperative burn.

I wish to report an unusual postoperative burn in a 79 year-old man undergoing a right total hip replacement. A pre-operative lumbar plexus block was performed and general anaesthesia induced. He was placed in the left lateral position with a beanbag to secure him and an axillary roll was placed under the dependent left axilla. The diathermy plate was attached to the left thigh. An upper body forced air-warming blanket (Bair Hugger ) and fluid warmer were used. His body temperature fell from 36.4 to 35.5 C during the procedure. He remained haemodynamically stable throughout the 4 h operation, during which he received 3 l of warmed crystalloids. On the second postoperative day, he complained of severe pain posterior and inferior to his left axilla. Examination revealed a mixed partial and full thickness burn (Fig. 1). The surface area of the burn was about 2% and required debridement and skin grafting. The cause of the burn in this patient was initially unclear but careful observation of the burn site showed it to correspond to the position of the axillary roll. The roll comprised a litre bag of crystalloid wrapped with a cotton towel and placed under the dependent axilla. The bag of fluid was obtained from a warming cabinet that maintains a fairly constant temperature of 37 C. Although the bag of fluid was at normal body temperature, the high specific heat capacity of water (4.18 J.g C) contributed to the transfer of heat to patient’s skin. Furthermore, the pressure exerted by the patient’s weight on the dependent, hypothermic and vasoconstricted skin over a long period of time probably resulted in the burn. A review of the literature revealed a report of two cases of intra-operative burns following the use of warmed IV bags [1]. Since this incident there has been a change in practice in our hospital. Rolled cotton blankets with or without a litre bag of fluid at room temperature are now employed. Operating room staff have been informed not to use warmed fluid bags from the warming cabinet as bolsters.