Abstract:

Objective

To observe the influence of transcutanclus electrical acupoint stimulation(TEAS) on postoperative cognitive dysfunction (POCD) and inflammation cytokines in elderly patients undergoing hip-replacement surgery.

Methods

A total of 53 elderly patients (over 75 years), undergoing elective total hip replacement surgery, were selected from January 2013 to December 2014 in Jiangsu Northern People's Hospital. Patients were divided into general anesthesia group (group A, n=26) and composite acupuncture anesthesia group (group B, n=27) according to the random number table. In group B，TEAS (2 /100 Hz, 8～12 mA) was used 30 min before the endotracheal general anesthesia until completing operation, at Baihui (GV 20), Neiguan (PC 6), and Fengchi(GB 20), with G6805-2 electric acupuncture apparatus. Patients were treated with controlled hypotension for reducing blood loss in two groups during operation. In group A, the endotracheal general anesthesia was applied without TEAS. Mini-mental state examination (MMSE) was adopted to evaluate and record the changes in cognitive function 24 h before operation and 72 h after operation. Enzyme-linked immunosorbent method was used to measure tumor necrosis factor-α (TNF-α), interleukin (IL)-1β and IL-6 before surgery，after surgery, 24 h and 72 h after surgery. SPSS18.0 statistical software was used to analyze data. The comparison between groups was analyzed using independent sample t test. The paired t test was used to compare results of treatment after itself. Data between groups at different time points were compared using repeated measures analysis of variance, and count data using χ² test. P<0.05 was considered statistically significant.

Results

The incidence rate of POCD was 38.5% (10/26) in A group, which was significantly higher than that of B group(29.9%, 7/27, t=2.641，P<0.05). There were significantly higher serum levels of IL-1β after operation,24h and 72h after operation than those before operation in two groups (t=7.968,10.038 and 12.652, P<0.05).The serum levels of IL-6 were significantly higher after surgery, 24h and 72h after surgery than those before operation in two groups (t=3.157,10.419 and 7.041，P<0.05). The serum levels of TNF-α were significantly higher 24 h and 72 h after surgery than those before operation in two groups (t=4.294 and 5.354, P<0.05). Compared with group A, the serum levels of TNF-α were significantly lower at 24 h and 72 h after operation in group B (t=4.362 and 5.020，P<0.05). The serum levels of IL-1β were significantly lower at 24 h and 72 h after operation in group B compared with those of group A (t=5.756 and 8.268,P<0.05).

Conclusion

TEAS can reduce the incidence rate of POCD in elderly patients undergoing hip-replacement surgery, which may be related to the inhibition of early postoperative inflammatory cytokine release.

Key words: Transcutaneous electric nerve stimulation, Arthroplasty，replacement，hip, Aged, Chemokines, Cognitive dysfunction