Effect of temperature on the partition coefficient of isoflurane and sevoflurane in perflurocarbon emulsion (Oxygent(TM)) / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of temperature on the partition coefficient of isoflurane and sevoflurane in perflurocarbonate emulsion (Oxygent(TM)).</p><p><b>METHODS</b>The partition coefficients of isoflurane and sevoflurane in perflurocarbonate emulsion (Oxygent(TM)) were measured at different temperatures (4, 22, 27, 32 and 37 degrees celsius;) using syringe-flask double headspace equilibration technique with gas chromatography, and the relationship between the partition coefficients and the temperature was analyzed.</p><p><b>RESULTS</b>At 4, 22, 27, 32 and 37 degrees celsius;, the partition coefficients of isoflurane in Oxygent(TM) were 85.30∓5.60, 40.48∓1.09, 37.14∓3.64, 27.38∓2.28 and 24.66∓1.03, and those of sevoflurane were 91.54∓5.40, 42.50∓0.91, 37.21∓2.76, 25.43∓1.03 and 28.05∓1.74, respectively. The partition coefficients of sevoflurane at 4, 22 and 37 degrees celsius; were significantly higher than those of isoflurane (P<0.05). The regression equations between the partition coefficient and temperature for isoflurane and sevoflurane were Y=-1.893X+89.20 (R(2)=0.942) and Y=-2.075X+95.58 (R(2)=0.951), respectively. An inverse linear relationship was found between temperature and the partition coefficient.</p><p><b>CONCLUSION</b>Within a specified range of temperatures, the partition coefficients isoflurane and sevoflurane decrease as the temperature increases. Sevoflurane shows a high solubility in Oxygent(TM) as compared to isoflurane.</p>

Comparison of single intubating dose and continuous infusion of rocuronium in prolonged gynecologic laparoscopic surgery / 南方医科大学学报

<p><b>OBJECTIVE</b>To compare the cardiorespiratory factors and surgical conditions during total intravenous anesthesia for prolonged laparoscopic pelvic surgery with or without supplemental muscle relaxants.</p><p><b>METHODS</b>Forty female ASA I or II patients undergoing laparoscopic pelvic surgeries were randomized into two groups A and B, both with standardized anesthesia via a intravenous bolus injection of rocuronium (0.6 mg/kg). The patients in group B received continuous rocuronium infusion upon observation of one TOF twitch response with the T1 value maintained within 0-10% and rocuronium withdrawal at 20 to 30 min before the completion of the surgery. The patients in group A received no supplemental muscle relaxants. The cardiorespiratory parameters were measured during the operation. The respiratory system compliance (Ceff rs) was calculated as the quotient of the tidal volume (VT) and peak inspiratory pressure (PIP), and the operative conditions were graded by the operating gynecologist.</p><p><b>RESULTS</b>The cardiorespiratory parameters significant increased and Ceff rs decreased after pneumoperitoneum, but no significant differences were found between the two groups. The surgical conditions were also comparable between the two groups, but the duration of intubation and the operating time were significantly shorter in the group A.</p><p><b>CONCLUSION</b>Pneumoperitoneum severely affects the cardiorespiratory parameters during laparoscopy, which can not be lessened by neuromuscular block agents. A single intubating dose of rocuronium can suffice the requirement of prolonged gynecologic laparoscopic surgery.</p>

Epidural butorphanol analgesia in elderly patients undergoing hip replacement / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the efficacy and safety of continuous epidural analgesia (CEA) with butorphanol in elderly patients undergoing hip replacement.</p><p><b>METHODS</b>Sixty patients scheduled for selective hip replacement were randomized into group B (n=30) to receive patient-controlled epidural analgesia (PCEA) with butorphanol and group M (n=30) to receive PCEA with morphine. Their pain distribution at 5 time points, postoperative global score and the adverse effects in 48 h were observed.</p><p><b>RESULTS</b>The pain distribution at the 5 time points or the global score for postoperative PCEA in 48 h showed no statistically significant difference between the two groups (P<0.05). Analgesia with butorphanol caused less adverse effects (respiratory depression, nausea and vomiting, itching and abdominal distension) than that with morphine (P<0.05).</p><p><b>CONCLUSION</b>CEA with butorphanol is safe and effective for the treatment of postoperative pain in elderly patients and causes less adverse effects than morphine.</p>