Journal of critical care
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Journal of critical care · Dec 1998
Clinical TrialUse of methylene blue in patients with refractory septic shock: impact on hemodynamics and gas exchange.
The purpose of this study was to assess the acute effects of methylene blue, an inhibitor of nitric oxide synthesis, on hemodynamics and gas exchange in patients with refractory septic shock in a prospective clinical trial at medical and surgical intensive care units in a tertiary university hospital. ⋯ Methylene blue had an acute vasopressor effect in patients with refractory septic shock, and it was not deleterious on respiratory function.
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Journal of critical care · Dec 1998
Role of neurosympathetic pathways in the vascular response to sepsis.
The aim of this study was to determine the role of sympathetic neural activity in the hemodynamic adaptations to sepsis in pigs with an emphasis on circuit adaptations. A fall in resistance to venous return (RVR) was predicted in contrast to what was previously observed in sympathetically intact animals that had no change in RVR. ⋯ Spinal section resulted in a more profound fall in blood pressure and less increase in MCFP than in previously studied animals with sympathetic nervous system intact, but there was still an increase in RVR and PAP ET-1 is a possible mediator of the increase in RVR and PAP.
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Journal of critical care · Dec 1998
Comparative Study Clinical TrialValidation of continuous thermodilution cardiac output in critically ill patients with analysis of systematic errors.
Bolus thermodilution cardiac output (BCO) measurements are affected by variations in injectate volume, rate, and temperature. These variations are eliminated when CO is measured by a continuous automated thermal technique (CCO). Further, CCO eliminates the need for fluid boluses, reduces contamination risk, requires no operator, and provides a continuous CO trend. We prospectively evaluated CCO versus BCO in a population of critically ill adults with low, normal, and high CO states. We sought to discern any systematic effects of temperature fluctuations or signal-to-noise-ratios (SNR) on disparities between BCO and CCO measurements and also sought to assess the relative cost effectiveness of the CCO system. ⋯ Continuous CO is a reliable and cost-effective alternative to bolus thermodilution CO for critically ill patients in low, normal, and high CO states.
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Journal of critical care · Dec 1998
Clinical Trial Controlled Clinical TrialClinical trial of an ex vivo arterial blood gas monitor.
The purpose of this study was to test the performance of a patient attached, on demand ex vivo arterial blood gas (ABG) monitor, and to compare the frequency of ABG analysis using the monitor, where the monitor was operated by intensive care unit (ICU) staff on shock trauma and neurosurgical intensive care patients for < or = 6 days, with standard clinical laboratory analysis. ⋯ The ABG monitor provides performance comparable to standard clinical laboratory analysis for < or = 6 days (< or = 144 hours), consistent with ICU arterial cannula changeout schedules. More frequent ABG analyses are obtained by critical care practitioners using the monitor compared with the clinical laboratory system, suggesting that clinical decision making based on ABG data may be limited by the frequency of ABG analysis.
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Journal of critical care · Dec 1998
ReviewContinuous cardiac output and mixed venous oxygen saturation monitoring.
Continuous assessment of cardiac output and SVO2 in the critically ill may be helpful in both the monitoring variations in the patient's cardiovascular state and in determining the efficacy of therapy. Commercially available continuous cardiac output (CCO) monitoring systems are based on the pulsed warm thermodilution technique. In vitro validation studies have demonstrated that this method provides higher accuracy and greater resistance to thermal noise than standard bolus thermodilution techniques. ⋯ The most recently designed pulmonary artery catheters are now able to simultaneously measure either SVO2 and CCO or SVO2 and right ventricular ejection fraction. This ability to view simultaneous trends of SVO2 and right ventricular performance parameters will probably allow the clinician to graphically see the impact of volume loading or inotropic therapy over time, as well as the influence of multiple factors, including right ventricular dysfunction, on SVO2. However, the cost-effectiveness of new pulmonary artery catheters application remains still questionable because no established utility or therapeutic guidelines are available.