The electrical effect of two commonly used clinical stimulators on traumatic edema in rats

The purposes of this study were to determine the effect of electrical stimulation on traumatic rat hind-paw edema and to establish whether there would be a difference in edema reduction when two types of stimulators were used. The animals were divided into a control group (n = 15) and two experimental groups, one group receiving monophasic pulsed current (MPC group, n = 15) and the other group receiving symmetrical biphasic pulsed current (SBPC group, n = 14). The right hind-paw volume of all groups was measured prior to traumatization and at 24, 48, 72, and 96 hours posttrauma. Following the 24-, 48-, and 72-hour measurements, 1 hour of electrical stimulation was administered to the experimental groups. The control group received sham treatment. Results revealed significant edema reduction in all groups over the 96-hour period, with each group's greatest change in paw volume occurring 48 hours posttrauma. At the final paw volume measurement, there was no significant difference between the MPC and control groups or between the MPC and SBPC groups. The SBPC group, however, showed less reduction in edema than did the control group. One hour of electrical stimulation per day over 3 consecutive days failed to demonstrate significant edema reduction in either the MPC group or the SBPC group as compared with the control group. The results of this study demonstrated that the electrical stimulation characteristics and procedures currently used in the clinic do not significantly reduce extant edema caused by trauma in rat hind limbs.