PRECAUTIONS IN WARMING LIGHT THERAPY AS AN ADJUVANT TO POSTOPERATIVE FLAP CARE

Warming lights, circulating-water blankets, space heaters, and the Bai r Hugger(R) are used by surgeons in the perioperative period to mainta in a patients core body temperature. Warming lights in particular are often used by plastic surgeons to augment the postoperative vasodilata tion of reconstructive flaps by increasing the ambient temperature of the area around the flap. A review of the literature fails to elucidat e even anecdotal experience regarding the actual intensity of thermal energy directly imparted to tissues from these modalities with respect to distance. The purpose of our study was to quantify actual tissue t emperatures generated, as a function of distance, with the Emerson(R) warming light. Our interest in this is a result of a full-thickness bu rn which occurred to a portion of a pedicled TRAM flap used for breast reconstruction when a warming light was inadvertently positioned, dur ing the course of the first postoperative night, at a distance less th an that recommended by the manufacturer. A biological model was create d simulating a sympathectomized flap and the temperature curves genera ted by Emerson(R) warming lights were recorded by calibrated glass bul b thermometers at 15 min intervals for distances of 32 and 71 cm using both focused and defocused light beams. The distance of 32 cm was use d as a parameter as it was the distance noted between the patient and the warming light when the TRAM flap burn occurred. Temperatures obtai ned at a distance of 32 cm rose to 120 degrees F (48.8 degrees C) with in 30 min for the focused beam and 118 degrees F (48 degrees C) after 1 h for the defocused beam. This exceeds the temperature at which tiss ue necrosis is known to occur (111.2 degrees F/44 degrees C). However. temperatures obtained at 71 cm for the focused and defocused beams pl ateaued at 93.2 and 96.8 degrees F (34 and 36 degrees C) respectively, which is well within physiologic limits and below the temperature res ulting in tissue necrosis. Our conclusion is that warming lights can b e successfully used as a safe adjuvant in order to optimize flap vasod ilatation without compromising the thermal threshold of tissue damage if maintained at the manufacturer's minimum recommended distance of 71 cm. If this source of thermal energy is used, however, strict precaut ions and nursing guidelines must be instituted to maintain this minimu m distance parameter and prevent patient morbidity. (C) 1998 Elsevier Science Ltd for ISBI. All rights reserved.