Mi Ae Cheong

Comparison of the adductor pollicis, orbicularis oculi, and corrugator supercilii as indicators of adequacy of muscle relaxation for tracheal intubation

BACKGROUND The purpose of this study was to verify which muscle among the adductor pollicis (AP), orbicularis oculi (OO), and corrugator supercilii (CS) is a better predictor of optimal intubating conditions after administration of rocuronium. METHODS In this prospective trial, 201 patients were randomized into six groups to receive rocuronium at a dose of 0.6 or 1.0 mg kg(-1) during propofol-remifentanil-nitrous oxide anaesthesia. The tracheal intubation was performed after maximal neuromuscular block by acceleromyography at the thumb (AP), the eyelid (OO), and the superciliary arch (CS). The onset time, intubating conditions, peak vital signs, and bispectral index were assessed. RESULTS The onset time of rocuronium in the OO and CS muscle was significantly shorter than in the AP muscle (P<0.001), but excellent intubating conditions were significantly increased in the AP (87%) and the CS (77%) compared with the OO (32%) after a dose of 0.6 mg kg(-1) of rocuronium (P<0.05). CONCLUSIONS After administration of rocuronium, twitch monitoring at the OO allows a faster intubation but is associated with an unacceptable incidence of inadequate intubating conditions. Excellent intubating conditions are observed most frequently with AP monitoring but with the longest delay before intubation is attempted. Monitoring of the CS allows intubation earlier than that of AP with fewer patients having excellent but no patients having inadequate intubating conditions.

Effect of ketorolac and diclofenac on the impairment of endothelium-dependent relaxation induced by reactive oxygen species in rabbit abdominal aorta

Background Reactive oxygen species (ROS) induce lipid peroxidation and tissue damage in endothelium. We studied the influences of ketorolac and diclofenac on ROS effects using the endothelium of rabbit abdominal aorta. Methods Isolated rabbit aortic rings were suspended in an organ bath filled with Krebs-Henseleit (K-H) solution bubbled with 5% CO2 and 95% O2 at 37.5℃. After being stimulated to contract with phenylephrine (PE, 10-6 M), changes in arterial tension were recorded following the cumulative administration of acetylcholine (ACh, 3 × 10-8 to 10-6 M). The percentages of ACh-induced relaxation of aortic rings before and after exposure to ROS, generated by electrolysis of K-H solution, were used as the control and experimental values, respectively. The aortic rings were pretreated with ketorolac or diclofenac at the same concentrations (10-5 M to 3 × 10-4 M), and the effects of these agents were compared with the effects of ROS scavengers: catalase, mannitol, sodium salicylate and deferoxamine and the catalase inhibitor, 3-amino-1,2,4-triazole (3AT). Results Both ketorolac and diclofenac maintained endothlium-dependent relaxation induced by ACh in a dose-related manner inspite of ROS attack (P < 0.05 vs. control value). The 3AT pretreated ketorolac (3 × 10-3 M) group was decreased more significantly than un-pretreated ketorolac (P < 0.05). Conclusions These findings suggest that ketorlac and diclofenac preserve the endothelium-dependent vasorelaxation against the attack of ROS, in a concentration-related manner. One of the endothelial protection mechanisms of ketorolac may be hydrogen peroxide scavenging.

The hemodynamic effects of a reversed Trendelenburg in elderly patients with increased cardiac risk during laparoscopic cholecystectomy

BACKGROUND We studied the hemodynamic changes induced by pneumoperitoneum and a reversed Trendelenburg in elderly patients with increased cardiac risk (ASA class III; n = 30; age 70.8 +/- 4.9 years, mean +/- SD) and compared the results with elderly patients at normal risk (ASA class II; n = 30; age 69.2 +/- 4.1 years) during laparoscopic cholecystectomy. METHODS The transesophageal Doppler monitor was performed after induction of general anesthesia (pre-incision), after onset of pneumoperitoneum (insufflation), after head-up (20degrees) and a left lateral tilt (15degrees) (reversed Trendelenburg) and after deflation and horizontal position (desufflation). Mean arterial pressure (MAP), heart rate, cardiac index (CI) and systemic vascular resistance (SVR) were measured, respectively. RESULTS Induction of pneumoperitoneum and head-up tilt in patients with cardiac risk resulted significantly in a decrease in CI and an increase in SVR compared with patients with normal risk (P < 0.05), and that remained until deflation, but no interval changes in MAP and heart rate. The CI, MAP and heart rate decreased and SVR increased significantly in patients with cardiac risk compared with patients with normal risk before incision (P < 0.05). No complications occurred. The results indicate that pneumoperitoneum and a reversed Trendelenburg are associated with significant but relatively benign hemodynamic changes. CONCLUSIONS Anesthesia for laparoscopic cholecystectomy in elderly patients with increased cardiac risk should be performed with an adequate hemodynamic monitoring.