OBJECTIVETo observe the effects of transcutaneous electrical acupoint stimulation (TEAS) on gastric emptying in patients undergoing selective surgery based on velocity of gastric emptying by ultrasonography.

METHODSA total of 75 patients with selective operation of subarachnoid block at lower limb in the afternoon were randomly assigned to a TEAS group, a sham group and a control group, 25 patients in each one. All the patients were provided with semi-fluid diet at 8 a.m. The TEAS group was treated with TEAS 5 min after semi-fluid diets at bilateral Zusanli (ST 36) and Neiguan (PC 6) for 30 min, with frequency of 5 Hz and intensity which was 1 mA lower than the tolerance threshold. The sham group patients were stimulated at the same acupoints with current intensity which was 1 mA lower than the sensory threshold. The control group received no treatment. On the day of operation, and ultrasonography was given at time of empty stomach (T0), immediately after the semi-fluid diets (T1), and every 30 min after diets (T2-T6), respectively, to measure the gastric content and emptying time at semire-clining position and right lateral position.

RESULTSThe volume of gastric content in the three groups at T3-T6 was significantly less than that at T1 (all<0.05). The volume of gastric content at T4-T6 at semire-clining position in the TEAS group was significantly less than that in the control group and sham group (all<0.05). The volume of gastric content at T5-T6 at right lateral position in the TEAS group was significantly less than that in the control group and sham group (all<0.05). The gastric emptying time in the TEAS group was significantly less than that in the control group and sham group (both<0.05).

CONCLUSIONThe gastric emptying velocity could be evaluated by ultrasonography. TEAS could improve the velocity of gastric emptying and reduce the gastric emptying time.