Mechanism of acupuncture anesthesia for analgesia of the operative region of thyroid gland / 中国针灸

<p><b>OBJECTIVE</b>To probe into peripheral nervous mechanisms of analgesic effect of electroacupuncture (EA) at Hegu (LI 4) and Neiguan (PC 6) on cervical region.</p><p><b>METHODS</b>Twenty cases of thyroid disease who wished to receive acupuncture anesthesia, were stimulated with electroacupuncture at bilateral Hegu (LI 4), Neiguan (PC 6) in continued wave, intensity of 6-8 V, frequency of 10-20 Hz. After stimulation for 40 min, the operation was made. Before EA stimulation, 10 min, 20 min and 30 min after EA stimulation, changes of the physiologi cal functions including latent period, conduction velocity, wave peak amplitude of great auricular nerve were monitored and changes of pain sense were detected.</p><p><b>RESULTS</b>After EA given at Hegu (LI 4) and Neiguan (PC 6) for 10 min, 20 min and 30 min, the pain sense significantly decreased (P<0.01), the latent period of great auricular nerve was shortened, and the conduction velocity was fastened and the wave peak amplitude raised with significant changes as compared with those before EA stimulation (P<0.01).</p><p><b>CONCLUSION</b>EA at Hegu (LI 4) and Neiguan (PC 6) can produce a better analgesic effect on cervical region; EA at Hegu (LI 4) and Neiguan (PC 6) induces electro-physio logic changes of the nerve innervating the cervical region, showing increase of excitability; the nerves innervating Hegu (LI 4) and Neiguan (PC 6) and the nerves of cervical region possibly are homologous nerves.</p>

Effect of acute hypervolemic hemodilution on pharmacokinetics of propofol in patients undergoing total hip replacement / 中华麻醉学杂志

Objective To investigate the influence of acute hypervolemic hemodilution(HHD)on pharmacokinetics of propofol.Methods Sixteen ASA Ⅰ or Ⅱ patients aged 20-55 yrs undergoing elective surgery under general anesthesia combined with epidural analgesia were randomly allocated into 2 groups(n=8 each);Ⅰ control group and Ⅱ HHD group.The patients were premedicated with intramuscular phenobarbital 0.1 g and scopolamine 0.3 mg.Right internal jugular vein was cannulated for CVP monitoring and blood sampling.Radial artery was cannulated for BP monitoring.All patients in both groups received lactated Ringer's solution(0.7 ml?kg~(-1)? number of hours of fasting before operation)before induction of general anesthesia.In HHD group 4% gelofusine 20 ml?kg~(-1) was infused at the rate of 20 ml?kg~(-1)?h~(-1).Anesthesia was induced with midazolam 0.04 mg?kg~(-1),fentanyl 4 ?g?kg~(-1) and propofol 1.5 mg?kg~(-1).Tracheal intubation was facilitated by succinylcholine 2 mg?kg~(-1).Anesthesia was maintained with isoflurane,fentanyl,vecuronium and epidural analgesia.ECG,BP, SpO_2,P_(ET)CO_2 and CVP were continuously monitored.Blood samples were taken at 1,2,4,6,10,15,30,45, 60,75,90,120,150,180,240,300 and 360 min after propofol was given Ⅳ for determination of plasma concentration of propofol(HPLC).Pharmacokinetic data were analyzed by 3P97 pharmacokinetic software.Results The two groups were comparable with respect to demographic data.Blood propofol concentrations were significantly lower in HHD group than in control group at 1,2,4,6,10 min after propofol injection(P＜0.01), thereafter there was no significant difference in plasma propofol concentration between the two groups(P＞0.05). The pharmacokinetic profile of propofol was well described by a standard three-compartment model.In HHD group V_C was significantly increased,K_(10) and Cl were significantly decreased and T_(1/2?) was significantly prolonged as compared with control group.Conclusion Acute HHD increases V_C,prolongs the T_(1/2?) and decreases K_(10) and Cl, suggesting that the effect of propofol may be potentiated by acute HHD.