Transient electric changes immediately after surgical trauma.

CONTEXT

Electric stimulation is frequently used to promote soft tissue healing, although we do not have a complete understanding of the tissue's electromagnetic properties.

OBJECTIVE

To measure the transient electric changes in skin and muscle tissue immediately after trauma.

DESIGN

1-group time series.

SETTING

Climate-controlled operating room in a public urban hospital.

PATIENTS OR OTHER PARTICIPANTS

Eleven participants (8 females, 3 males) with a mean age of 65.18 +/- 11.36 years undergoing total hip arthroplasty.

INTERVENTION(S): An incision approximately 10 cm distal to the posterior superior iliac spine extended distally over the greater trochanter and along the lateral limb. The incision was completed in 2 cuts: (1) skin and subcutaneous fat and (2) muscle tissue.

MAIN OUTCOME MEASURE(S): Three measurement sessions were performed with an electrometer before and after a skin incision and after a muscle incision. Potential differences and current intensity were measured immediately after acute trauma to determine the transient electric changes associated with soft tissue injury.

RESULTS

The electric potentials were significantly more negative after the skin incision (P = .036) and skin plus muscle incision (P = .008; preincision = 0.001 +/- 0.015 V, skin incision = -0.127 +/- 0.134 V, skin plus muscle incision = -0.192 +/- 0.153 V). Current intensity changed significantly after the skin plus muscle incision (P = .008; preincision = 0.046 +/- 0.112 pA, skin incision = -0.803 +/- 0.904 pA, skin plus muscle incision = -1.708 +/- 1.302 pA).

CONCLUSIONS

Soft tissue trauma generated negative transient electric changes.