Masui. The Japanese journal of anesthesiology
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To evaluate the effect of prostagrandin E1 (PGE1)-induced hypotension on cerebral blood flow (CBF) and carbon dioxide (CO2) reactivity of CBF, regional cerebral hemoglobin oxygen saturation (rSo2) was measured in non-neurosurgical patients (n = 10) under sevoflurane-anesthesia using near infrared spectroscopy. PGE1 was infused intravenously to maintain arterial pressure at a level of about 75% of the MAP (hypotensive group) under sevoflurane-anesthesia alone (normotensive group). Ventilation was controlled to adjust PaCO2 to hypocapnia (25-30 mmHg), normocapnia (35-40 mmHg) and hypercapnia (45-50 mmHg) in both normotensive and hypotensive groups. rSo2 during hypotension did not change by hypocapnia and normocapnia, but significantly increased by hypercapnia, compared with rSo2 during normotension. ⋯ When arterial oxygen content and cerebral metabolic rate of oxygen are constant, changes in rSo2 correlate with those of CBF. Therefore, CBF and CO2 reactivity of CBF that indicates autoregulation in response to changes in CO2 during hypotension were maintained as those during normotension. The results show that PGE2-induced hypotension maintains CBF and CO2 reactivity well in non-neurosurgical patients under sevoflurane anesthesia.
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We report a case of drug-induced laryngospasm due to Chlorpromazine. A drug-induced laryngospasm has not been previously reported in the literature. A 70-year-old male with the proximal end fracture of the femur was scheduled for the operative fixation. ⋯ Immediate oral intubation was performed and no complications ensued during and after the operation. This episode strongly suggests that one reason of the unexplained sudden deaths of patients receiving long term treatment with chlorpromazine could be laryngospasm. In conclusion, anesthesiologists should be aware of the possibility of laryngospasm under similar conditions.
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A program for on-line simulation of blood propofol concentration was developed. Various pharmacokinetic model programs are available for the estimation of intravenous anesthetic concentration. But manual entry of data such as body weight, rate of infusion and the timing of changing the flow rate is mandatory in these programs. ⋯ Based on the obtained data, pharmacokinetic model was solved with personal computer. Calculated blood concentrations of propofol were displayed in a numeric form and a trend graph was obtained. This program provides useful information for maintainance of anesthesia with propofol.
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Comparative Study
[Effects of halothane and sevoflurane on reversal of neuromuscular blockade induced by vecuronium in man].
To evaluate residual effects of inhalational anesthetics after reversal of neuromuscular blocking agent, neuromuscular function was monitored after halothane or sevoflurane anesthesia in thirty-seven patients (ASA physical status I or II) for elective surgery after obtaining informed consent. Electromyograph of the adductor pollicis muscle in response to train of four (TOF) stimulation was monitored throughout the study. The first twitch of TOF (T1; % of its control) and the ratio of the fourth twitch to the first twitch of TOF (T4/T1; TR) were recorded at 0, 2, 5, 10, and 15 min after reversal. ⋯ Both T1 (75.4 +/- 12.2%) and TR (68.0 +/- 12.6%) at 15 min after the reversal during 3% sevoflurane inhalation were below those of the stable group. We conclude that the residual sevofulrane after discontinuation of inhalation may impair the neuromuscular transmission after the reversal of neuromuscular blockade. Neuromuscular function should be monitored after the end of anesthesia even though the patient is fully awake.
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A 33 year-old parturient with triplet pregnancy underwent emergency cesarean section at 35 week of gestation under general anesthesia. The patient had received magnesium sulfate to prevent uterine contraction immediately before the cesarean section. Although serum magnesium value was not beyond therapeutic levels (3.3 mEq.l-1), the neuromuscular blocking effects with vecronium were strengthened. ⋯ In addition, it is possible that magnesium could interfere with postpartum uterine contractions because of its tocolytic properties. Magnesium sulfate therapy has several implications to anesthetic agents. We, anesthesiologists, should know about the biophysiological effects of magnesium and control the interaction between anesthetic agents and this electrolyte.