Gastric dynamics analysis of TEAS combined SNP induced general anesthesia when controlled hypotension dropped to 60% of the MAP baseline / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To observe the effect of gastric dynamics by transcutaneous electrical acupoint stimulation (TEAS) combined general anesthesia when controlled hypotension dropped to 60% of the mean arterial prenssure (MAP) baseline, and to provide experimental evidence for organ protection in clinical controlled hypotension.</p><p><b>METHODS</b>Eighteen male beagles were randomly divided into three groups, the general anesthesia group (blank), the general anesthesia induced controlled hypotension group (control), and the general anesthesia combined TEAS induced controlled hypotension group (experiment), 6 in each group. Controlled hypotension was performed in the latter two groups with isoflurane inhalation and intravenous injection of sodium nitroprusside (SNP). The mean arterial pressure (MAP) was lowered to 60% of the MAP baseline and kept for 60 min. Controlled hypotension was not performed in Beagles of the control group. For Beagles in the experiment group, TEAS [2/100 Hz, (4 ± 1) mA] was applied to bilateral Hegu (LI4), Quchi (LI11), Zusanli (ST36), and Sanyinjiao (SP6) from stable physiological conditions to the end of maintaining stages. Changes of EGG frequencies and EGG amplitudes were monitored. Serum levels of gastrin (GAS) and motilin (MTL) were also detected at corresponding time points during and after experiment.</p><p><b>RESULTS</b>As for the pressure control effect of TEAS combined general anesthesia in the controlled hypotension, during the process of controlled hypotension (T1-T4), MAP levels of two controlled pressure groups remained relatively stable, and were kept at 60% of the MAP baseline. When the blood pressure dropped to the target low MAP and maintained at 60 min (T1-T4), EGG amplitudes of Beagles in all the three groups showed decreasing tendency. But it was more obviously lower than its basic level in the control group (P <0.05), while it was not obviously decreased in the experiment group (P < 0.05). EGG frequencies of Beagles in all the three groups showed no obvious change during this stage. By the end of the MAP rising stage (T8), the EGG amplitude of the experimental group was significantly higher than that of the control group and the blank group (P < 0.05), while it didn' t show any obvious increase in the control group. During this period, EGG frequencies of the two controlled hypotension groups decreased more than those of the blank group. Two h after rising blood pressure (at T9), EGG amplitudes and frequencies in the two controlled hypotension groups basically restored to their respective baselines and levels of the blank group at T9. At 2 h (T9) after controlled hypotension, serum levels of GAS and MTL were lower than those of basic levels in the two controlled hypotension groups (P <0.05). However, serum levels of GAS and MTL had an increasing trend in the two controlled hypotension groups at 24-72 h (T10-T12). Besides, the increasing speed and amplitude was better in experiment group than in the control group at T10-T12. However, there was no statistical difference between the two groups (P > 0.05). At 72 h (T12) serum levels of GAS and MTL had basically restored to their basic levels in the two controlled hypotension groups and that of the blank control group.</p><p><b>CONCLUSION</b>EGG amplitudes could be effectively improved in TEAS combined general anesthesia for controlled hypotension at 60% of the MAP baseline, the recovery of the serum GAS level accelerated, gastric power improved and stomach protected.</p>

Effects of transcutaneous electrical acupoint stimulation combined with general anesthesia for controlled hypotension on heart function and oxidation resistance of myocardium / 中国针灸

<p><b>OBJECTIVE</b>To investigate the intervention effect of transcutaneous electrical acupoint sitmulation (TEAS) on heart under limiting level of controlled hypotension.</p><p><b>METHODS</b>Eighteen male Beagles were randomly divided into a general anesthesia group, a control group and an experimental group, 6 dogs in each group. All animals were applied with general anesthesia, and the animals of the control group and the experimental group were administered with combination of isoflurane and sodium nitroprusside (SNP) for controlled hypotension to 30% mean arterial pressure (30% MAP) of base line for 60 min. In the experimental group, TEAS (2 Hz/100 Hz, 6-8 mA) was applied to "Hegu" (LI4), "Zusanli" (ST 36), "Sanyinjiao" (SP 6) and "Quchi" (LI 11) from the beginning of physiological conditions stability to the end of maintained low MAP for 60 min. Creatine kinase isoenzymes MB (CK-MB) and lactate dehydrogenase (LDH) activity were detected at the base line and 2 h, 24 h, 48 h, 72 h after operation. Total superoxide dismutase (T-SOD) and malondialdehyde (MDA) in myocardium were observed at 72 h after operation.</p><p><b>RESULTS</b>The peak of LDH arrived at 24 h after operation and then restored in 3 groups. Compared with basal level, the activity of LDH in controlled group at 72 h after operation was significantly increased (P < 0.05), and in the other two groups no obvious change (P > 0.05). The activity of CK-MB arrived to peak from 2 h to 24 h after operation, and then came back gradually in 3 groups. Compared with postoperative 72 h of the same group, the control group at 48 h significantly increased (P < 0.05), while the other two groups had no statistically significant difference (P > 0.05). The content of MDA at 72 h after operation in controlled group was higher significantly than that in the general anesthesia group and the experimental group (both P < 0.05).</p><p><b>CONCLUSION</b>TEAS combined with anesthesia for controlled hypotension can elevate myocardial effect of anti-oxide free radical, reduce the postoperative release of LDH and CK-MB, so as to produce myocardial protection.</p>