Anesthesia and analgesia
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Anesthesia and analgesia · Sep 1987
Comparative StudyInfluence of age on vascular absorption of lidocaine from the epidural space.
The purposes of this study were to evaluate the effect of age on the vascular absorption of local anesthetics during epidural anesthesia and to corroborate the clinical observations of other investigators with respect to age. Using the arbitrary definition of significance (P less than 0.05), the maximum serum levels of lidocaine (Csmax) did not differ significantly with age, however, P values were equal to 0.06. Furthermore, the time to Csmax was significantly faster in elderly patients (P less than 0.00001). In conclusion, the mass of local anesthetic solution should be reduced in elderly patients undergoing epidural anesthesia because there is a greater segmental spread, and serum levels of local anesthetics are increased.
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Anesthesia and analgesia · Sep 1987
Randomized Controlled Trial Comparative Study Clinical TrialComparison of high-frequency jet ventilation with conventional mechanical ventilation for bronchopleural fistula.
In seven patients with acute respiratory failure and a bronchopleural fistula, the authors compared gas exchange and volume of gas lost via the chest tube during conventional mechanical ventilation (CV) and high-frequency jet ventilation (HFJV). After the initial comparison, patients were randomized to HFJV or CV, unless one mode of ventilation was clearly superior based on preestablished criteria. In six of the seven patients, oxygenation deteriorated after the switch from CV to HFJV. ⋯ The mean chest tube leak did not change significantly. Randomization of the mode of ventilation was not performed in any patient because CV was superior by a priori criteria. We conclude that when acute respiratory failure is complicated by a bronchopleural fistula, HFJV with mean airway pressures comparable to those provided during conventional ventilation does not provide satisfactory gas exchange.
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Anesthesia and analgesia · Sep 1987
Comparative StudyCerebral autoregulation and flow/metabolism coupling during cardiopulmonary bypass: the influence of PaCO2.
Measurement of 133Xe clearance and effluent cerebral venous blood sampling were used in 38 patients to determine the effects of cardiopulmonary bypass, and of maintaining temperature corrected or noncorrected PaCO2 at 40 mm Hg on regulation of cerebral blood flow (CBF) and flow/metabolism coupling. After induction of anesthesia with diazepam and fentanyl, mean CBF was 25 ml X 100 g-1 X min-1 and cerebral oxygen consumption, 1.67 ml X 100 g-1 X min-1. Cerebral oxygen consumption during nonpulsatile cardiopulmonary bypass at 26 degrees C was reduced to 0.42 ml X 100 g-1 X min-1 in both groups. ⋯ However, variation in CBF correlated significantly with cerebral perfusion pressure over the pressure range of 15-95 mm Hg. This study demonstrates a profound reduction in cerebral oxygen consumption during hypothermic nonpulsatile cardiopulmonary bypass. When a non-temperature-corrected PaCO2 of approximately 40 mm Hg was maintained, CBF was lower, and analysis of pooled data suggested that CBF regulation was better preserved, i.e., CBF was independent of pressure changes and dependent upon cerebral oxygen consumption.