Anesthesia and analgesia
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Anesthesia and analgesia · Nov 1982
Criteria for selection of ambulatory surgical patients and guidelines for anesthetic management: a retrospective study of 1553 cases.
The charts of 1553 patients who were anesthetized for ambulatory surgery were analyzed retrospectively to determine the effect of the type of surgery, the age of the patient, the use of premedication, the duration of anesthesia, and the anesthetic technique on the duration of recovery and the rate of complications. In a 4-month period in 1979, 1073 patients were treated, and another 480 patients were treated during a 2-month period in 1980. Aside from patients undergoing dental surgery, the surgical procedure and the extremes of age affected neither the duration of recovery (193 +/- 97 minutes) nor the rate of complications (2.45%). ⋯ There was no relationship between anesthesia time and the duration of recovery. Patients who received local anesthesia had a significantly shorter recovery period than the whole population, and significantly fewer patients receiving local anesthesia had to be admitted to the hospital. Thus, arbitrary limits placed on the type of surgery, age of the patient, the duration of the procedure, and the use of certain premedication appear to be unwarranted.
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Concentrations of halogenated anesthetics produced by contemporary vaporizers vary from vaporizer dial settings when carrier gas is not 100% oxygen. This effect is most marked when carrier gas changes from 100% O2 to 100% nitrous oxide (N2O). ⋯ Steady-state outputs of halothane and enflurane in 100% N2O were 10% below dial settings. The significance of these changes in administration of closed-circuit anesthesia with an out-of-circuit vaporizer is discussed.
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Anesthesia and analgesia · Oct 1982
Onset and progression of intravenous regional anesthesia with dilute lidocaine.
Intravenous regional anesthesia was induced in seven healthy volunteers using dilute lidocaine solution. Onset and progression were documented by sequential detailed neurologic examinations and compared with changes following intravenous regional administration of normal saline. ⋯ Motor paralysis could precede or follow sensory loss in tissues supplied by the same peripheral nerve; the only consistent finding was persistence of strength in the flexor digitorum profundus of the little finger. The pattern of development of intravenous regional anesthesia was related to the anatomic distribution of the peripheral nerves; it is hypothesized that the primary mechanism of action is block of the small distal nerve branches.
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Anesthesia and analgesia · Oct 1982
Prophylactic intravenous ephedrine infusion during spinal anesthesia for cesarean section.
Ephedrine sulfate was administered to 44 healthy parturients undergoing elective repeat cesarean section under spinal anesthesia. Twenty patients received ephedrine infusion (0.01% solution, beginning with approximately 5 mg/min) immediately after induction of spinal anesthesia to maintain maternal systolic blood pressure between 90% and 100% of the base line systolic blood pressure (mean dose of ephedrine 31.6 mg). Twenty-four patients (control group) received 20 mg of ephedrine as an intravenous bolus, and additional 10-mg increments, if necessary when systolic blood pressure decreased to 80% of the base line systolic blood pressure (mean dose of ephedrine 26.8 mg). ⋯ Nausea and/or vomiting occurred in nine women in the control group and one patient in the infusion group (p less than 0.01). Apgar scores, fetal blood gas tensions, and time for onset of respiration were comparable in the two groups. The results suggest that prophylactic ephedrine infusion is safe and desirable in healthy parturients undergoing cesarean section under spinal anesthesia.