Both the ETC and ETT perform comparably well. Slight differences could be found with respect to time of insertion in favor of the ETC. Because this is the first experiment using the ETC on the KC-135, it is shown that there is enough time to perform the insertion procedure. Because the ETC airway requires less training and is easier to insert than an ETT, it is recommended for further study as an alternative airway to what is currently on the shuttle.

We have read with interest the article by Charuluxananan et al. (1) that compares the effectiveness of nalbuphine and ondansetron in the prevention of intrathecal morphine-induced pruritus after cesarean delivery. The authors found that prophylactic nalbuphine and ondansetron were both effective in reducing pruritus but not nausea and vomiting induced by 0.2 mg of intrathecal morphine.In a similar study (2), we assessed the efficacy of ondansetron for the prevention of pruritus, nausea, and vomiting induced by intrathecal sufentanil-morphine in 100 patients undergoing cesarean delivery. Doses of drugs used were 8 mg of ondansetron, 0.1 mg of morphine, and 2.5 g of sufentanil. The incidence of nausea and vomiting, in this study, was significantly reduced in the treatment group when compared with the placebo group (18% vs 48%; P ϭ 0.001). However, the incidence of pruritus was not decreased in the treatment group when compared with the placebo group (76% versus 82%; P ϭ 0.46). These results are not in agreement with the data reported by Charuluxananan et al. Failure of ondansetron to prevent pruritus in our study may be explained by the fact that sufentanil-which is a highly lipophilic opioid with a quick onset of action-was added to intrathecal morphine. The serotonin receptors in the spinal cord were probably activated by sufentanil before they were blocked by ondansetron. Furthermore, and because the incidence of nausea and vomiting following intrathecal opioids is dosedependent (3), the effectiveness of ondansetron in our study could be related to the low dose (0.1 mg) of the intrathecally administrated morphine as compared with the higher dose (0.2 mg) used by Charuluxananan et al.In conclusion, prophylactic ondansetron decreases the incidence of intrathecal opioid-induced pruritus, nausea, and vomiting after cesarean delivery. However, ondansetron may not be effective when highly lipophilic opioids or increased doses of morphine are administrated.(0.2 mg vs 0.1 mg), and different scales of pruritus and nauseavomiting scales (4-point scale versus 3-point scale). We agree that the serotonin receptors in the spinal cord were probably activated by sufentanil before they were blocked by ondansetron, which may be the reason of failure of ondansetron for prevention of pruritus in his study. Although in our study there was no statistical significant difference in the severity of nauseavomiting, the percentage of patients with severe nausea or vomiting (nausea-vomiting score 3, 4) of 4 mg nalbuphine, 4 mg ondansetron, 8 mg ondansetron, and placebo were 15%, 8%, 9% and 24%, respectively (P ϭ 0.053), which showed the tendency of prophylactic efficacy of nausea and vomiting. Moreover, the prophylactic success rate of nausea-vomiting by ondansetron in our study and Yazigi et al.'s study were comparable (81% vs 82%). Therefore, more data or more valid trials are needed.

Remifentanil infusions and meperidine boluses are equally well tolerated in older patients undergoing ambulatory colonoscopy when administered by an anesthesia provider.

No abstract

Based on references 16-18, 21. The 6-D method of airway assessment helps practitioners remember to assess for each of the six signs that can be associated with a difficult intubation. Each sign begins with the letter D like the word difficult. The potential for difficult intubation is generally proportional to the number of signs observed.