Anesthesia and analgesia
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Anesthesia and analgesia · Mar 1985
Large volume crystalloid resuscitation does not increase extravascular lung water.
The purpose of this study was to determine whether Ringer's lactate solution increases extravascular lung water (EVLW) during resuscitation after hemorrhagic shock. Ten sheep anesthetized with thiamylal were bled to a mean arterial pressure (MAP) of 50 mm Hg; further bleeding maintained that pressure for 30 min. Resuscitation fluid consisted of Ringer's lactate solution in volumes necessary to restore and maintain for 1 hr MAP, pulmonary capillary wedge pressure (PCWP), and cardiac index at levels equal to those measured before bleeding. ⋯ After volume restoration, COP decreased from 19 +/- 8 mm Hg to 12 +/- 2 mm Hg (P less than 0.001). Despite the large volume of fluid administered, EVLW did not increase. Crystalloid resuscitation does not necessarily increase EVLW despite significant decreases in COP and COP - PCWP gradient.
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Anesthesia and analgesia · Jan 1985
Enflurane and adenosine 3',5'-cyclic monophosphate metabolism in pancreatic islets.
The effects of enflurane at a concentration of 4% by volume in the gas phase upon rates of insulin secretion were correlated with islet contents of adenosine 3',5'-cyclic monophosphate (cyclic AMP). At this concentration, enflurane was without effect upon the basal rate of insulin release in the presence of 2 mM glucose. By contrast, the anesthetic led to 84 and 86% inhibitions, respectively, of rates of insulin secretion stimulated by 20 mM glucose and 20 mM glucose plus 1 mM theophylline. ⋯ By contrast, the anesthetic led to significant inhibitions of both basal and fluoride-stimulated islet adenylate cyclase activity (34%, P less than 0.01 and 23%, P less than 0.005, respectively). It is concluded that under the conditions employed, enflurane leads to inhibition of islet adenylate cyclase activity and to small resultant reductions in islet cyclic AMP content. These effects appear to be of insufficient magnitude to explain completely the observed degree of insulin secretory inhibition by the anesthetic.
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Anesthesia and analgesia · Dec 1984
Cerebral and cardiopulmonary responses to high-frequency jet ventilation and conventional mechanical ventilation in a model of brain and lung injury.
The cardiopulmonary and intracranial effects of high-frequency jet ventilation (HFJV) were evaluated in four groups of 10 mongrel dogs and compared to conventional mechanical ventilation with and without positive and expiratory pressure (PEEP). Each group of animals was studied with various combinations of normal and abnormal brain and lung function. Experimental brain injury (abnormal cerebral elastance) was produced by infusion of saline into the subarachnoid space to increase intracranial pressure (ICP), while lung injury resulted from intratracheal instillation of 0.1N HCl. ⋯ ICP responses did not vary significantly with the different modes of ventilation and were not influenced by the status of lung or brain function. However, significant reductions in cerebral perfusion pressure were noted with 20 cm H2O PEEP compared to HFJV. We conclude that unless high levels of PEEP (15-20 cm H2O) are required for adequate oxygenation, the cardiovascular and cerebral effects of HFJV do not differ significantly from those of conventional mechanical ventilation.