The influence of local versus global heat on the healing of chronic wounds in patients with diabetes.
BACKGROUND
In a previous study, it was shown that placing a subject with chronic diabetic ulcers in a warm room prior to the use of electrical stimulation dramatically increased the healing rate. However, global heating is impractical in many therapeutic environments, and therefore in the present investigation the effect of global heat versus using a local heat source to warm the wound was investigated.


METHODS
Twenty-nine male and female subjects participated in a series of experiments to determine the healing associated with electrical stimulation with the application of local heat through a heat lamp compared to global heating of the subject in a warm room. Treatment consisted of biphasic electrical stimulation at currents at 20 mA for 30 min three times per week for 4 weeks in either a 32 degrees C room or, with the application of local heat, to raise skin temperature to 37 degrees C. Skin blood flow was measured by a laser Doppler imager.


RESULTS
Blood flow increased with either local or global heating. During electrical stimulation, blood flow almost doubled on the outside and on the edge of the wound with a smaller increase in the center of the wound. However, the largest increase in blood flow was in the subjects exposed to global heating. Further, healing rates, while insignificant for subjects who did not receive electrical stimulation, showed 74.5 +/- 23.4% healing with global heat and 55.3 +/- 31.1% healing with local heat in 1 month; controls actually had a worsening of their wounds.


CONCLUSIONS
The best healing modality was global heat. However, there was still a significant advantage in healing with local heat.
Department of Physical Therapy, School of Allied Health Professions, Loma Linda University, Loma Linda, California 92350, USA. jpetrofsky@llu.edu
Jerrold S
JS
Petrofsky
Daryl
D
Lawson
Hye Jin
HJ
Suh
Christine
C
Rossi
Karina
K
Zapata
Erin
E
Broadwell
Lindsay
L
Littleton
D000368:Aged; D000369:Aged, 80 and over; D003924:Diabetes Mellitus, Type 2 / Q000150:complications; D017719:Diabetic Foot / Q000503:physiopathology / Q000628:therapy*; D004558:Electric Stimulation; D006361:Heating; D006358:Hot Temperature / Q000627:therapeutic use*; D006801:Humans; D007259:Infrared Rays / Q000627:therapeutic use*; D008875:Middle Aged; D012039:Regional Blood Flow; D012867:Skin / Q000098:blood supply; D014945:Wound Healing / Q000528:radiation effects*