Cool-Water Immersion and High-Voltage Electric Stimulation Curb Edema Formation in Rats

OBJECTIVE: Although cryotherapy and high-voltage electric stimulation, both alone and in combination, are commonly applied to curb acute edema, little evidence from randomized controlled studies supports these procedures. Our purpose was to examine the effects of cool-water immersion (CWI) at 12.8 degrees C (55 degrees F), cathodal high-voltage pulsed current (CHVPC) at 120 pulses per second and 90% of visible motor threshold, and the combination of CWI and CHVPC (CWI + CHVPC) on edema formation after impact injury to the hind limbs of rats. DESIGN AND SETTING: Both feet of 34 rats were traumatized after hind-limb volumes were determined. Animals were randomly assigned to 1 of 3 groups: CWI (n = 10), CHVPC (n = 10), or CWI + CHVPC (n = 14). One randomly selected hind limb of each rat was exposed to four 30-minute treatments, interspersed with four 30-minute rest periods beginning immediately after posttraumatic limb volumes were determined. Contralateral limbs served as controls. Limbs remained dependent during all treatments, rest periods, and volumetric measurements. SUBJECTS: We used 34 anesthetized Zucker Lean rats in this study. MEASUREMENTS: We measured limb volumes immediately before and after trauma and after each of 4 treatment and rest periods. RESULTS: Volumes of treated limbs of all 3 experimental groups were smaller (P