Anesthesia and analgesia
-
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.
-
Anesthesia and analgesia · Oct 1982
Hepatic centrilobular necrosis in rats after exposure to halothane, enflurane, or isoflurane.
Exposure of phenobarbital-pretreated rats to low concentrations of halothane (0.5%) and reduced oxygen tension (FIO2 0.08) resulted in the development of liver necrosis in 51% of the animals. Fasting of rats for 24 hours before the same type of exposure increased the incidence of liver necrosis to 80%. Exposure of fed rats to enflurane (1.5%) and isoflurane (1.4%) in conjunction with low oxygen tensions resulted in no liver necrosis; however, in fasting animals, these same concentrations, when accompanied by low oxygen concentrations, produced an incidence of liver necrosis of 35% and 80%, respectively. ⋯ In this study, in addition to increasing the incidence of toxicity, fasting reduced the glutathione levels and also increased cytochrome P-450 concentrations. Exposure to halothane and to isoflurane, but not to enflurane, further decreased the glutathione level. Perhaps the mechanism of liver toxicity associated with anesthesia, at least in this animal model, is related more directly to severe hypoxia than to a direct toxic intermediate produced as a result of metabolism.
-
Anesthesia and analgesia · Sep 1982
Comparative StudyComparative cardiovascular effects of midazolam and thiopental in healthy patients.
Midazolam, a water-soluble benzodiazepine that is shorter-acting, more potent, and less irritating to veins than diazepam, has been suggested for use for induction of anesthesia. The cardiovascular effects of an induction-sized dose (0.25 mg/kg) of midazolam in A. S. ⋯ Midazolam is, then, as acceptable for induction of anesthesia as thiopental from a hemodynamic point of view in A. S. A. class I and II patients.