Effects of dexmedetomidine on propofol dosage in target-controlled infusion and hemodynamics during laparoscopic surgery under general anesthesia / 南方医科大学学报

<p><b>OBJECTIVE</b>To assess the effects of dexmedetomidine (Dex) on propofol dosage in target-controlled infusion (TCI) and hemodynamics in patients undergoing laparoscopic surgery under general anesthesia.</p><p><b>METHODS</b>Sixty patients undergoing laparoscopic surgery under general anesthesia were randomly divided into control group (n=30) and the Dex group (n=30). The patients in Dex group received a loading dose of Dex (1 µg/kg, infused within 10 min) before the surgery followed by continuous infusion at the rate of 0.3 µg·kg(-1)·h(-1) till the end of the surgery, and the control patients received saline infusion in the same manner. Heart rate, blood pressure, bispectral index (BIS), and propofol dose in TCI were recorded during induction and maintenance of anesthesia. The incidence of hypotension and bradycardia were observed during and after the surgery.</p><p><b>RESULTS</b>No difference was found in the incidence of hypotension and bradycardia between the control group and Dex group (P>0.05), but heart rate and blood pressure were lower in Dex group during extubation (P<0.05). The dose of propofol in TCI was significantly less in Dex group than in the control group (P<0.05).</p><p><b>CONCLUSION</b>Dex can reduce hemodynamic abnormalities caused by extubation and decrease the dosage of propofol in TCI, and may serve as an ideal adjuvant drug for general anesthesia.</p>

Changes of approximate entropy in rats during focal cerebral infarction / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the changes of EEG approximate entropy (ApEn) in rats during focal cerebral infarction.</p><p><b>METHODS</b>Twenty-four Sprague-Dawley (SD) rats were randomly divided into infarction group (n=12) with middle cerebral artery occlusion and sham-operated group (n=12). The EEG data (ApEn) was recorded in the bilateral areas (C3, C4) of the rats with focal cerebral infarction before the infarction and immediately and at 5, 15, 30, and 60 min after the infarction. The same measurement was carried out in the sham-operated group.</p><p><b>RESULTS</b>In the sham-operated group, ApEn in C3 and C4 showed no obvious differences at the time points (P>0.05), but in the infarction group, ApEn in C3 and C4 increased significantly after the infarction. ApEn in the ischemic area (C4) was significantly lower than that in the non-ischemic area (C3) (P<0.05). The bilateral ApEn decreased with the passage of time. ApEn in the ischemic area (C4) was significantly lowered at 30 min after the infarction in comparison with that before infarction (P<0.05). In the sham-operated group, ApEn showed no significant difference between C3 and C4. ApEn was comparable between the two groups before the operation.</p><p><b>CONCLUSION</b>ApEn can help monitor the occurrence of focal cerebral infarction of rats, and may be used to assess the extent of cerebral ischemia after infarction.</p>

Prophylactic effect of acupuncture on nausea and vomiting after laparoscopic operation / 中国针灸

<p><b>OBJECTIVE</b>To explore the prophylactic effect of acupuncture Neiguan (PC 6) on nausea and vomiting after laparoscopic operation.</p><p><b>METHODS</b>One hundred patients with laparoscopic gastrointestinal operation were randomly divided into an acupuncture group and a control group, 50 patients in each group. The operation was carried out with the combined infusion and inhalation anesthesia. The patients in the acupuncture group were being punctured at bilateral Neiguan (PC 6) before anesthesia and during the operation. The needles were extracted after operation, and the acupoints were covered with opaque tape. In contrast, the patients in the control group only accepted tape covering without acupuncture. After operation, all patients were given the self-controlled intravenous analgesia, and followed up at 6 h, 12 h, 24 h, 48 h for recording the incidence rate of the nausea, retching and vomiting, then scoring with VAS.</p><p><b>RESULTS</b>At 6 h, 12 h, 24 h, 48 h after operation, in the acupuncture group, the incidence rates of the nausea were 12.0%, 6.0%, 6.0% and 2.0%, and the incidence rates of the retching were 0, 0, 2.0% and 2.0%, respectively; in the control group, the incidence rates of the nausea were 28.0%, 20.0%, 12.0% and 2.0%, and the incidence rates of the retching were 2.0%, 6.0%, 2.0% and 0, respectively. At 6 h, 12 h after operation, the incidence rates of the nausea and retching in the acupuncture group were lower than those of the control group (P < 0.05, P < 0.001). The vomiting was not happened in both groups. There was no difference between the two groups according to the scoring with VAS.</p><p><b>CONCLUSION</b>Acupuncturing at Neiguan (PC 6) can reduce the incidence rates of the patients' nausea and retching after laparoscopic operation, especially in 24 h.</p>

Comparison of unconsciousness prediction probability with approximate entropy and bispectral index during sedation / 南方医科大学学报

<p><b>OBJECTIVE</b>To compare the unconsciousness prediction probability (Pk) estimated by approximate entropy (ApEn) and bispectral index (BIS) during the sedation produced by target-controlled infusion (TCI) of propofol.</p><p><b>METHODS</b>Twenty patients (ASA class I-II) scheduled for elective lower limb operations under epidural anesthesia were studied. TCI of propofol was initiated at target plasma concentration of 0.5 microg/ml, and increased by 0.3 to 0.5 microg/ml until loss of consciousness, and then decreased until consciousness recovery. Each target plasma concentration of propofol lasted for 12 min. ApEn and BIS were recorded simultaneously during the periods of consciousness and unconsciousness every 3 min. The Pk of unconsciousness with ApEn and BIS were calculated and compared.</p><p><b>RESULTS</b>ApEn was 0.84+/-0.05 in the state of consciousness and 0.71+/-0.06 upon loss of consciousness, and BIS in the corresponding stages were 80.2+/-6.2 and 67.3+/-7.9, respectively. The Pk of unconsciousness between ApEn (Pk=0.97+/-0.06) and BIS (Pk=0.91+/-0.11) did not significantly differ (P>0.05).</p><p><b>CONCLUSION</b>ApEn as well as BIS is acceptable for predicting consciousness and unconsciousness produced by TCI propofol.</p>