Journal of critical care
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Journal of critical care · Sep 1997
The effects of intravenous anesthetics on intracranial pressure and cerebral perfusion pressure in two feline models of brain edema.
The purpose of this study was to investigate the effects of various intravenous anesthetics on intracranial pressure (ICP) and cerebral perfusion pressure (CPP) in two models of brain edema in a prospective study in a Pediatric critical care animal laboratory in a university hospital. ⋯ Our results indicate that i.v. anesthetics decrease ICP caused by SOL but have no significant effect on ICP due to CBE. We postulate that in the SOL model, and similarly in VBE, some brain tissue is viable and remains responsive to anesthetics. In contrast, in the CBE model, diffuse intracellular damage occurs, the cerebral metabolic rate may be severely depressed, autoregulation of the cerebral vasculature may be impaired, and unresponsiveness to i.v. anesthetics may occur.
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Journal of critical care · Sep 1997
Comparative StudyContinuous jugular bulb venous oxygen saturation validation and variations during intracranial aneurysm surgery.
During intracranial aneurysm surgery, numerous factors may alter cerebral blood flow and oxygen supply-demand balance. Continuous monitoring of jugular bulb venous oxygen saturation (SvjO2) may help in the anesthetic management of such procedures. ⋯ Although the accuracy of fiberoptic SvjO2 determination is limited, it allows the detection of cerebral blood flow and oxygen supply-demand imbalance during aneurysm surgery. The frequent occurrence of SvjO2 elevations is suggestive of reactive hyperemia mechanisms.
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Journal of critical care · Sep 1997
An outcomes analysis of in-hospital cardiopulmonary resuscitation: the futility rationale for do not resuscitate orders.
Cardiopulmonary resuscitation (CPR) is a frequently performed medical intervention in hospitalized patients who die. Despite the widespread use of do-not-resuscitate (DNR) orders during the last decade, the outcome following CPR appears not to have improved. The key to an improved outcome may be better patient selection. The objective of this study was to determine the hospital survival rate following CPR in the era of DNR orders, and to identify risk factors predictive of hospital survival at a university-affiliated teaching hospital. ⋯ DNR protocols do not prevent CPR being performed on patients who are unlikely to survive to hospital discharge. CPR should only be offered to patients who are likely to derive benefit from this intervention.
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Journal of critical care · Sep 1997
Changes in thoracopulmonary compliance and hemodynamic effects of positive end-expiratory pressure in patients with or without heart failure.
The purpose of this study was to confirm that positive end-expiratory pressure (PEEP) has a different effect on cardiac index (CI) in patients with or without heart failure, even after controlling for differences in thoracopulmonary compliance (Ctp) and minimizing the secondary effects of PEEP related changes in oxygenation and breathing effort. ⋯ We conclude that (1) the observed different effect of PEEP on CI in patients with and without heart failure persists after the elimination of secondary effects due to underlying differences in Ctp, oxygenation, and breathing effort; and (2) PEEP-related changes in Ctp should be taken into consideration when dealing with the cardiovascular effects of PEEP. Our data support the hypothesis that, in addition to the transmission of PEEP to the pleural space, changes in lung volume are a significant determinant of PEEP-induced CI changes.
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Journal of critical care · Sep 1997
Influence of fluid resuscitation on renal function in bacteremic and endotoxemic rats.
Fluid resuscitation, which is the most important primary therapy in sepsis, is not always able to prevent acute renal failure. In this study, we investigated in two different rat models of distributive shock whether fluid resuscitation would increase renal plasma flow (RPF) and subsequently glomerular filtration rate (GFR). ⋯ In conclusion, our study suggests that a decrease in GFR caused by live bacteria in the circulation may benefit from fluid resuscitation, while during endotoxemia this therapy could not prevent acute renal failure.