Anesthesia and analgesia
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Anesthesia and analgesia · Sep 1993
Comparative StudyNeurotoxicology of chronic infusion of the ganglioside GM1 in the ewe: phase I. intrathecal administration.
Gangliosides, including GM1, provide a measure of improved functional recovery after ischemic, toxic, and traumatic brain injuries in animal studies. Since systemically injected GM1 has provided equivocal results in a variety of human neurodegenerative conditions, the possibility exists that intrathecal or intracerebroventricular delivery might provide more effective concentrations along the neuroaxis. In preparation to consider clinical trials, the potential neurotoxicologic effects of chronic intrathecal GM1 were studied in ewes. ⋯ In both treated and control groups, the only consistent finding was a pericatheter-associated compression of white matter with axonal dilation, vacuolation, and occasional neuronal loss. Catheter tracts in both groups were also associated with variable leptomeningeal fibroproliferative changes in adjacent dura and pia, at times in conjunction with more generalized duromeningeal thickening. In summary, chronic intrathecal GM1 in doses up to 10 mg/d had no definable neuropathologic consequences.
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Anesthesia and analgesia · Sep 1993
Selecting ventilator settings according to variables derived from the quasi-static pressure/volume relationship in patients with acute lung injury.
Knowledge of the pressure/volume (P/V) relationship of the lung may allow selection of tidal volume and positive end-expiratory pressure (PEEP) to optimize gas exchange without adversely affecting lung function or hemodynamics. Ten patients with acute lung injury were stabilized on controlled mechanical ventilation, based on conventional practice, using criteria from arterial blood gas data. The P/V relationship was determined under quasi-static conditions (end-expiratory and end-inspiratory, no flow periods > 0.8 s) during mechanical ventilation with an automated procedure that changed PEEP in a stepwise fashion. ⋯ Intrapulmonary shunt decreased from 0.28 +/- 0.08 (baseline) to 0.14 +/- 0.05 (12 h) (P < 0.001). Hemodynamic variables did not change. Our data suggest that using variables derived from a quasi-static P/V loop during mechanical ventilation under muscle paralysis is clinically superior compared to blood gas criteria for titration of ventilator settings.
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Anesthesia and analgesia · Sep 1993
Randomized Controlled Trial Comparative Study Clinical TrialMuscle paralysis by rocuronium during halothane, enflurane, isoflurane, and total intravenous anesthesia.
We determined the dose-response relationship, the onset time, the duration, and the recovery time of a rocuronium neuromuscular block under four anesthesia techniques. Patients were equally randomized to four different groups (n = 20) receiving 0.5%-1% halothane, 1.5%-2% enflurane, 1.2%-1.8% isoflurane end-tidal concentration in 34%/66% O2/N2O, or 6.0 mg.kg-1 x h-1 propofol without N2O for anesthesia and alfentanil for analgesia. Strength of thumb adduction in response to single and train-of-four stimulation of the ulnar nerve was quantitated. ⋯ There was a statistically significant difference between the halothane and TIVA, and between the enflurane and TIVA groups (P < 0.05). Rocuronium has a short onset time and an intermediate duration of action. The neuromuscular blocking potency and pharmacodynamic profile are moderately influenced by volatile anesthetics.