Articles: general-anesthesia.
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Randomized Controlled Trial Comparative Study Clinical Trial
Arterial oxygen saturation during induction of anaesthesia and laryngeal mask insertion: prospective evaluation of four techniques.
In a prospective, randomized study of 87 patients, we have compared the incidence of hypoxaemia during induction of anaesthesia with subsequent Laryngeal Mask Airway (LMA) insertion in healthy adults when four different techniques were used: one without supplementary oxygen, and three with supplementary oxygen. Twelve patients did not receive supplementary oxygen before LMA placement, 25 underwent partial denitrogenation by breathing oxygen from the start of injection of the induction agent, 25 underwent formal denitrogenation by breathing oxygen for 3 min, and 25 received five tidal volume breaths of oxygen by face mask using positive pressure immediately after induction of anaesthesia. Anaesthesia was induced with propofol 2.0 mg kg-1 and fentanyl 1 microgram kg-1. ⋯ Desaturation occurred in 11 of 12 patients who did not receive supplementary oxygen, and in 19 of 25 patients who received manual ventilation with 100% oxygen after induction of anaesthesia before LMA insertion. Full denitrogenation and partial denitrogenation were equally successful in preventing desaturation. Failure to position the LMA successfully occurred in 3% of patients, and some difficulty was encountered in another 18%.
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Randomized Controlled Trial Comparative Study Clinical Trial
Esmolol hydrochloride for management of the cardiovascular stress responses to laryngoscopy and tracheal intubation.
In a double-blind, randomized, controlled prospective study, 30 grade ASA I/II patients received a continuous i.v. infusion of normal saline or esmolol hydrochloride before induction of anaesthesia and tracheal intubation. Arterial pressure and heart rate were measured to assess the pressor response to laryngoscopy and intubation. The heart rate decreased in the esmolol group before induction of anaesthesia. The pressor response to laryngoscopy was significantly less marked in the esmolol group.
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Randomized Controlled Trial Clinical Trial
Electroconvulsive therapy-induced cardiac arrhythmias during anesthesia with methohexital, thiamylal, or thiopental sodium.
To determine the frequency of electroconvulsive therapy (ECT)-induced arrhythmias under methohexital, thiamylal, or thiopental sodium anesthesia with and without atropine premedication. ⋯ These data suggest that anesthesia for ECT therapy should be induced with methohexital to minimize the possibility of potentially life-threatening cardiac arrhythmias. Atropine premedication may further decrease the frequency of premature atrial contractions and bradycardia, while increasing the frequency of tachycardia.
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It has recently been reported that the use of halogenated agents during balanced general anesthesia may result in an increase in blood loss associated with cesarean section. This report has been criticized for failure to control for a variety of other factors that may have contributed to the increased blood loss, particularly the indication for and type of cesarean section. The present study was designed in an attempt to resolve this criticism. ⋯ A greater proportion of women undergoing general anesthesia experienced a postoperative decrease in hematocrit of 5 vol% or more compared with patients receiving regional anesthesia (10 of 42 versus 5 of 75, p = 0.018). Thus, we conclude that women undergoing uncomplicated elective repeat cesarean section under general anesthesia supplemented with a halogenated agent are at risk for increased blood loss compared with those women receiving regional anesthesia. However, the increased blood loss was not clinically significant in this study, since none of the patients required transfusion.