Anesthesia and analgesia
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Anesthesia and analgesia · Jan 2004
Clinical TrialChronic treatment with antipsychotics enhances intraoperative core hypothermia.
Antipsychotics can induce hypothermia, but intraoperative temperature regulation in schizophrenic patients taking antipsychotics remains unclear. We investigated intraoperative temperature regulation and postoperative shivering in chronic schizophrenic patients receiving antipsychotics. We studied 30 schizophrenic patients and 30 control patients who underwent orthopedic surgery. Tympanic membrane temperatures (35.7 degrees C +/- 0.5 degrees C, 35.6 degrees C +/- 0.5 degrees C, 35.6 degrees C +/- 0.4 degrees C, 35.5 degrees C +/- 0.4 degrees C, 35.4 degrees C +/- 0.5 degrees C, and 35.4 degrees C +/- 0.3 degrees C) 15, 30, 45, 60, 75, and 90 min, respectively, after induction in schizophrenic patients were significantly (P < 0.001) lower than those (36.5 degrees C +/- 0.5 degrees C, 36.4 degrees C +/- 0.5 degrees C, 36.3 degrees C +/- 0.4 degrees C, 36.2 degrees C +/- 0.5 degrees C, 36.2 degrees C +/- 0.4 degrees C, and 36.1 degrees C +/- 0.4 degrees C) in control patients. Mean skin temperatures (31.1 degrees C +/- 0.4 degrees C [P = 0.008], 31.1 degrees C +/- 0.3 degrees C [P = 0.007], and 31.1 degrees C +/- 0.2 degrees C [P = 0.006]) 60, 75, and 90 min, respectively, after induction in schizophrenic patients were significantly lower than those (31.5 degrees C +/- 0.3 degrees C, 31.5 degrees C +/- 0.3 degrees C, and 31.5 degrees C +/- 0.3 degrees C) in control patients. Four of 30 schizophrenic patients and 7 of 30 control patients developed postanesthesia shivering. There were no significant differences within 1 h after tracheal extubation in tympanic membrane temperatures between patients who shivered and those who did not shiver. In conclusion, chronic schizophrenic patients were more hypothermic during anesthesia. The incidence of postanesthesia shivering was not significantly increased. ⋯ Antipsychotics inhibit autonomic thermoregulation. This is caused by decreased heat production, increased heat loss, and impaired central action at the hypothalamus. Thus, schizophrenic patients receiving antipsychotics may have impaired intraoperative temperature regulation.
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Anesthesia and analgesia · Jan 2004
Case ReportsPyloromyotomy in a patient with paramyotonia congenita.
A 2-mo-old infant with paramyotonia congenita was scheduled for pyloromyotomy and repair of inguinal hernia. Diagnosis of paramyotonia congenita was done with positive family history, myotonia at eyelids, provocation by cold, and electromyogram analysis. Anesthesia was induced via face mask with sevoflurane at 4 minimum alveolar anesthetic concentration in oxygen. Tracheal intubation was attempted without a neuromuscular relaxant. Anesthesia was maintained with sevoflurane at 0.5 minimum alveolar anesthetic concentration in oxygen and remifentanil infusion at a rate of 0.2 micro g. kg(-1). min(-1). After discontinuation of sevoflurane and remifentanil, the patient was awake and had full recovery of muscle activity. ⋯ The literature concerning general anesthesia in paramyotonic patients is limited. We report a case of paramyotonia congenita in a 2-mo-old male infant undergoing surgery for pyloric stenosis and inguinal hernia after an uneventful anesthesia.
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Anesthesia and analgesia · Jan 2004
Ventilation-perfusion distribution related to different inspiratory flow patterns in experimental lung injury.
In acute lung injury (ALI), controlled mechanical ventilation with decelerating inspiratory flow (.V(dec)) has been suggested to improve oxygenation when compared with constant flow (.V(con)) by improving the distribution of ventilation and perfusion (.V(A)/.Q). We performed the present study to test this hypothesis in an animal model of ALI. Furthermore, the effects of combined decelerating and constant flow (Vdot;(deco)) were evaluated. Thus, 18 pigs with experimental ALI were randomized to receive mechanical ventilation with either .V(con), .V(dec) or a fixed combination of both flow wave forms (.V(deco)) at the same tidal volume and positive end-expiratory pressure level for 6 h. Hemodynamics, gas exchange, and .V(A)/.Q distribution were determined. The results revealed an improvement of oxygenation resulting from a decrease of pulmonary shunt within each group (P < 0.05). However, blood flow to lung areas with a normal .V(A)/.Q distribution increased only during ventilation with .V(con) (P < 0.05). Accordingly, PaO(2) was higher with .V(con) than with .V(dec) and .V(deco) (P < 0.05). We conclude that contrary to the hypothesis, .V(con)provides a more favorable .V(A)/.Q distribution, and hence better oxygenation, when compared with .V(dec) and .V(deco) in this model of ALI. ⋯ In acute lung injury, mechanical ventilation with decelerating flow has been suggested to improve ventilation-perfusion distribution when compared with constant flow. We tested this hypothesis in an animal model. Contrary to the hypothesis, we found a more favorable ventilation-perfusion distribution during constant flow when compared with decelerating flow.
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Anesthesia and analgesia · Jan 2004
Comment Letter Comparative StudyDueling fiberoptic bronchoscope techniques.