Anesthesia and analgesia
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Anesthesia and analgesia · Nov 1998
Clinical TrialAssessment of oropharyngeal distance in children using magnetic resonance imaging.
Rational determination of oral airway size in children must account for the oropharyngeal length. We used magnetic resonance imaging (MRI) to measure the distance from the teeth/gums to the prevertebral pharyngeal space and created algorithms to predict this distance based on age, weight, and gender. After institutional review board approval, we reviewed 200 MRI head scans of children 0-17 yr old. Patient information, including midline distance from teeth/gums to prevertebral space (L1) and distance along a perpendicular line from L1 to the epiglottis tip (L2), was recorded. Two groups (Group 1 (n = 100) training group, Group 2 (n = 100) validation group) were then randomly selected from this sample. Predictive models created using Group 1 were tested using Group 2 as the sample group. Oropharyngeal distance was related to age, weight, and gender. A prediction equation using all data was estimated to determine the final model: predicted L1 = 5.51 + 0.25 (age [years]) -0.01 (age2) + 0.02 (weight [kg]) + 0.12 (male). We report equations to predict the oropharyngeal distance based on age, weight, and gender in children. The oral airway size will be 1-2 cm longer than these measurements to position the tooth/lip guard outside the lip. Variability in the distance to the epiglottis must be considered when selecting proper oral airway size for any child. This information will provide the foundation for a more rational determination of the proper oral airway size for infants and children. ⋯ Age, weight, and gender can be used to predict the length of the oropharynx in children as determined by midline sagittal magnetic resonance image of the airway. Prediction of this length will lead to a more rational determination of proper oral airway size for infants and children and, potentially, more effective airway management.
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Anesthesia and analgesia · Nov 1998
Clinical TrialGynecologic laparoscopic surgery is not associated with an increase of serotonin metabolites excretion.
Gynecologic laparoscopic surgery is associated with a high incidence of postoperative nausea and vomiting (PONV). The specific antagonists of the 5-hydroxytryptamine-3 (5-HT3) receptor have been progressively introduced in anesthesiology to prevent or treat PONV. Although a large increase of serotonin has been documented after cisplatin treatment, the link between serotonin and PONV in surgery/anesthesiology is unknown. In a prospective study, we compared the excretion of the serotonin metabolite 5-hydroxyindoacetic acid (5-HIAA) in 40 women undergoing either gynecologic laparoscopic surgery (laparoscopy group) or traditional open laparotomy surgery (laparotomy group). Premedication, anesthetic technique, and postoperative pain treatment were standardized. The excretion of 5-H IAA corrected to creatinine was measured in all patients immediately after the induction of anesthesia and was repeated regularly until 9 h after induction. The excretion of 5-HIAA/creatinine was similar in the two groups; no increase was observed in either group. The incidence of nausea and vomiting was 40% and 35%, respectively, in the laparoscopy group versus 60% and 15%, respectively, in the laparotomy group (not significantly different). The excretion of 5-HIAA/creatinine was comparable in patients of both groups among those who vomited and those who did not. We conclude that the creation of a pneumoperitoneum during gynecologic laparoscopic surgery is not associated with an increase of 5-HIAA excretion. PONV after gynecologic laparoscopic surgery is not explained by an increase of serotonin secretion. ⋯ The mechanism leading to the high incidence of postoperative nausea and vomiting after gynecologic laparoscopic surgery is unknown. The excretion of the serotonin metabolite 5-hydroxyindoacetic acid did not increase during the creation of the pneumoperitoneum and the first 9 h postoperatively. Increase of serotonin secretion from the gut may not explain postoperative nausea and vomiting associated with this surgery.