Anesthesia and analgesia
-
Anesthesia and analgesia · Nov 1993
Randomized Controlled Trial Clinical TrialCerebral awakening concentration of sevoflurane and isoflurane predicted during slow and fast alveolar washout.
We studied 49 patients of ASA physical status I to determine cerebral anesthetic concentration on awakening calculated with end-tidal anesthetic concentration, when the end-tidal concentration decreased spontaneously. We also attempted to explain the difference in the average of the bracketing alveolar anesthetic concentration that allows and prevents the response to verbal command during recovery from anesthesia (MAC-Awake) between slow and fast alveolar washout by comparing the cerebral anesthetic concentrations with MAC-Awake determined by fast and slow washout. Slow washout was obtained by decreasing anesthetic concentrations in predetermined steps of 15 min, assuming equilibration between brain and alveolar partial pressures. ⋯ MAC-Awake values obtained by fast washout (0.22 +/- 0.07 MAC for sevoflurane, 0.22 +/- 0.05 MAC for isoflurane) were significantly smaller than those obtained by slow washout. Anesthetic concentrations in the brain at first eye opening calculated with end-tidal concentrations during fast alveolar washout (0.34 +/- 0.08 MAC for sevoflurane, 0.30 +/- 0.08 MAC for isoflurane) were nearly equal to MAC-Awake obtained by slow alveolar washout. The difference in MAC-Awake between fast and slow alveolar washout could be explained by arterial-to-cerebral and end-tidal-to-arterial anesthetic differences.
-
Anesthesia and analgesia · Nov 1993
Comparative StudySerum inorganic fluoride levels in mildly obese patients during and after sevoflurane anesthesia.
Serum inorganic fluoride levels in obese versus control patients were compared during and after sevoflurane anesthesia. Mean serum inorganic fluoride levels in the obese group increased more rapidly and were significantly higher than in the control group at each sampling time (P < 0.01). ⋯ Peak serum fluoride level in the obese patients was 51.7 +/- 2.5 mumol/L and exceeded 50 mumol/L for nearly 2 h. Our study showed that serum fluoride concentrations between mildly obese and nonobese patients differed during and after sevoflurane anesthesia.
-
Anesthesia and analgesia · Nov 1993
Monitoring of intraoperative motor-evoked potentials under conditions of controlled neuromuscular blockade.
Motor-evoked potentials were recorded after electrical spinal cord stimulation in 19 patients undergoing neurosurgical or orthopedic procedures. Anesthesia was maintained with nitrous oxide, opioids, and inhaled anesthetics. Vecuronium was infused sufficient to eliminate 90% of twitch tension. ⋯ Intraoperative deterioration of motor-evoked potentials occurred in one patient who had a postoperative neurologic deficit. This study demonstrates the feasibility and utility of intraoperative motor tract monitoring using direct spinal cord stimulation. Controlled neuromuscular blockade permits recording of compound muscle action potentials while eliminating patient motor activity that could interfere with surgery.