The effects of plasma fentanyl concentrations on propofol requirement, emergence from anesthesia, and postoperative analgesia in propofol-nitrous oxide anesthesia.

Unlabelled: To determine the effects of plasma fentanyl concentrations on intraoperative propofol requirements, emergence from anesthesia, and relief of postoperative pain, we studied 60 ASA physical status I and II patients undergoing spine fusion. The patients were randomly assigned to four study groups according to the expected intraoperative plasma fentanyl concentrations. Group I received an infusion of saline, and Groups II, III, and IV received fentanyl infusions to maintain the blood levels at 1.

Effects of general and locoregional anesthesia on reproductive outcome for in vitro fertilization: a meta-analysis.

The objective of this meta-analysis was to evaluate prospective trials of general or locoregional anesthesia on reproductive outcomes (cleavage and pregnancy rate) for in vitro fertilization (IVF). Of 115 published studies retrieved from a search of articles indexed on MEDLINE from 1966 to February 1999, four studies with distinct general and locoregional anesthesia were deemed eligible for meta- analysis. The pooled relative risk and odds ratios were calculated.

Prediction on lengths of stay in the postanesthesia care unit following general anesthesia: preliminary study of the neural network and logistic regression modelling.

The length of stay in the postanesthesia care unit (PACU) following general anesthesia in adults is an important issue. A model, which can predict the results of PACU stays, could improve the utilization of PACU and operating room resources through a more efficient arrangement. The purpose of study was to compare the performance of neural network to logistic regression analysis using clinical sets of data from adult patients undergoing general anesthesia.

Prediction of oculocardiac reflex in strabismus surgery using neural networks.

Successfully predicting an oculocardiac reflex (OCR) is difficult to achieve despite various proposed maneuvers. The aim of this study was to test the models built up by neural networks to predict the occurrence of OCR during strabismus surgery in children. Premedication was not given.

Dexamethasone treatment does not ameliorate subglottic ischemic injury in rabbits.

Background: Following tracheal intubation, a small proportion of patients develop laryngeal inflammation or tissue necrosis severe enough to result in clinical symptoms. Although corticosteroids are frequently advocated to prevent such injury, human studies have been inconclusive because of the low incidence of the problem. This study developed a rabbit model of endotracheal tube-induced laryngeal injury to test the hypothesis that a corticosteroid, dexamethasone, could ameliorate the inflammation and necrosis.

Brain temperature alters hydroxyl radical production during cerebral ischemia/reperfusion in rats.

Selective neuronal cell death in the CA1 pyramidal cells of the hippocampus and neurons of the dorsolateral striatum as a consequence of brain ischemia/reperfusion (IR) can be ameliorated with brain hypothermia. Since postischemic injury is mediated partially by chemical production of reactive oxygen species (ROS), decreased ROS production may be one of the mechanisms responsible for cerebral protection by hypothermia. To determine if ischemic brain temperature alters ROS production, reversible IR was produced in rats by occlusion of both carotid arteries with hemorrhagic hypotension.

Effects of dexamethasone on laryngeal edema following short-term intubation.

Following short-term intubation for general anesthesia, respiratory difficulty may result from laryngeal or subglottic edema after extubation. We have hypothesized that this problem could be pretreated by administering a high-dose of dexamethasone intravenously before extubation. After glottic injuries were made under direct laryngoscopic view, intubation was performed and maintained for 1 hour in 33 rabbits.

Jet ventilation using fiberoptic bronchoscopes.

A fiberoptic bronchoscope is used to facilitate tracheal intubation in cases of difficult direct laryngoscopy. Occasionally, difficulty is encountered in advancing the endotracheal tube after the fiberoptic bronchoscope has been introduced into the trachea. This study tested the feasibility of providing jet ventilation through the suction channel of the fiberoptic bronchoscope as an interim measure under those or similar circumstances.

Effect of prophylactic bronchodilator treatment on lung resistance after tracheal intubation.

Background: After induction of anesthesia, lung resistance increases. We hypothesized that prophylactic bronchodilator treatment before tracheal intubation would result in a lower lung resistance after placement of the endotracheal tube.

Methods: Forty-two adult patients were randomized to receive one of three inhaled medications 1 h before surgery.

Head position and oral vs nasal route as factors determining endotracheal tube resistance.

Study Objective: We performed this in vitro study to determine the following: (1) if there is any significant difference in resistance between comparably sized endotracheal tubes (ETTs) in simulated anatomic oral and nasal conformations: (2) if neck flexion would increase the resistance of the ETT; and (3) if a wire-reinforced tube in simulated oral conformation would minimize the resistance increase at bends in the tube.

Design: The pressure drops (the change in pressure the flow through the ETT) at the proximal end of three sizes of tubes (6-, 7-, and 8-mm inner diameter) were measured in anatomic conformations at flows ranging from 20 to 100 L/min with the tubes warmed to 37 degrees C.

Results: There were no significant differences in pressure drops between comparably sized ETTs in the nasal vs oral conformation at any flow tested.