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.
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Anesthesia and analgesia · Nov 1998
Randomized Controlled Trial Clinical TrialIntraarticular triamcinolone acetonide for pain control after arthroscopic knee surgery.
Intraarticular corticosteroids provide valuable local therapy for chronic joint pain caused by inflammatory joint diseases. In this inpatient study, we evaluated the effect of intraarticular triamcinolone acetonide on acute pain after arthroscopic knee surgery. Sixty patients who underwent arthroscopic knee surgery under spinal anesthesia were enrolled into this double-blind, randomized trial. At the end of surgery, Group 1 (n = 30) received intraarticular triamcinolone acetonide 10 mg in isotonic saline 20 mL, and Group 2 (n = 30) received intraarticular isotonic saline 20 mL. After surgery, pain was assessed by using a visual analog scale. The time to first analgesic request (IV morphine) was recorded, and the proportion of patients requiring rescue analgesia was calculated. The results demonstrated that patients in Group 1 had lower pain scores than those in Group 2 from 6 to 24 h postoperatively (P < 0.05 to P < 0.01). From 6 h to 24 h, no patient in Group 1, compared with 53% of patients in Group 2, requested rescue analgesia (P < 0.001). We conclude that intraarticular triamcinolone acetonide provides a valuable local therapy of acute joint pain after arthroscopic knee surgery. ⋯ The value of intraarticular triamcinolone acetonide in the management of pain after arthroscopic knee surgery has been evaluated. Patients who received intraarticular triamcinolone acetonide 10 mg at the end of surgery had lower pain scores and used less systemic analgesia than the saline control group. These data are important to the clinical use of this new therapy.
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Anesthesia and analgesia · Nov 1998
Randomized Controlled Trial Comparative Study Clinical TrialAutoregulation of human inner ear blood flow during middle ear surgery with propofol or isoflurane anesthesia during controlled hypotension.
We used controlled hypotension to obtain a bloodless cavity during middle ear surgery under an optical microscope. No previous study has assessed the effect of controlled hypotension on inner ear blood flow (IEF) autoregulation in humans receiving propofol or isoflurane anesthesia. In the present study, the IEF autoregulation was determined using laser Doppler flowmetry in combination with transient evoked otoacoustic emissions (TEOAEs) during controlled hypotension with sodium nitroprusside in 20 patients randomly anesthetized with propofol or isoflurane. A coefficient of IEF autoregulation (Ga) was determined during controlled hypotension, with a Ga value ranging between 0 (no autoregulation) and 1 (perfect autoregulation). During controlled hypotension with propofol, IEF remained stable (1%+/-6%; P > 0.05) but decreased by 25%+/-8% with isoflurane (P < 0.05). The Ga was higher during propofol anesthesia (0.62+/-0.03) than during isoflurane anesthesia (0.22+/-0.03; P < 0.0001). Under propofol anesthesia, there were individual relationships between TEOAE amplitude and change in IEF in four patients. Such a correlation was not observed under isoflurane anesthesia. These results suggest that human IEF is autoregulated in response to decreased systemic pressure. Furthermore, isoflurane has a greater propensity to decrease cochlear autoregulation and function than propofol. ⋯ The present study shows that inner ear blood flow is autoregulated under propofol, but not isoflurane, anesthesia during controlled hypotension in humans during middle ear surgery. Further studies are needed to explore the postoperative auditory functional consequences of the choice of the anesthetic drug used in middle ear surgery.
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Anesthesia and analgesia · Nov 1998
Randomized Controlled Trial Clinical TrialThe cholecystokinin antagonist proglumide enhances the analgesic efficacy of morphine in humans with chronic benign pain.
The analgesic efficacy of morphine is sometimes only partial in patients with chronic benign pain. Among the possible factors contributing to this limitation are increased levels of cholecystokinin (CCK). We performed this prospective, placebo-controlled, double-blind, cross-over study to examine the effect of proglumide, a nonspecific CCK agonist, on analgesia in patients taking morphine on a chronic basis. Forty patients with intractable pain who were taking sustained-release morphine were recruited, and we obtained results from 36 of these patients. Median visual analog scale scores before the study were 8 and 7 after the addition of placebo for 2 wk (P = 0.16), and 6 after proglumide for 2 wk (P = 0.002). Mobility was unchanged by proglumide or placebo. Of the 36 patients, 13 elected to continue receiving proglumide after the study. We conclude that proglumide enhances the analgesia produced by morphine in some, but not all, patients with chronic benign pain. ⋯ The pain-killing effect of morphine is incomplete in some patients. Increasing doses may be needed to maintain the initial effect. The peptide cholecystokinin may be partially responsible for this. In this study, we demonstrated that the cholecystokinin antagonist proglumide increases the analgesic effect of morphine in some patients with chronic benign pain.