Critical care medicine
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Critical care medicine · Nov 1997
Clinical TrialBrief episodes of ventricular fibrillation do not influence postischemic cerebral perfusion assessed by positron emission tomography.
To establish the defibrillation threshold in patients receiving an implantable cardioverter defibrillator, at least three episodes of ventricular fibrillation are induced and converted back to regular rhythm, using direct current countershocks. The aim of this study was to examine the influence of repeated short episodes of ventricular fibrillation on global and regional cerebral perfusion. ⋯ Short episodes of ventricular fibrillation did not induce any measurable effects on global and regional cerebral perfusion detectable by positron emission tomography 30 secs and 10 mins after restitution of sinus rhythm.
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Critical care medicine · Nov 1997
Comparative StudyEffects of inhaled nitric oxide and extracorporeal membrane oxygenation on pulmonary hemodynamics and lymph flow in oleic acid lung injury in sheep.
To compare the effects of inhaled nitric oxide (NO) and extracorporeal membrane oxygenation (ECMO) on oxygenation, hemodynamics, and lymphatic drainage in an oleic acid lung injury model in sheep. ⋯ In an oleic acid-induced sheep model of acute lung injury, there were significant differences between the effects of NO and ECMO on acute pulmonary hypertension, hypoxemia, hypercarbia, and lymph flow. NO significantly decreases pulmonary hypertension, whereas pulmonary hemodynamics were not substantially affected by ECMO. Both interventions reversed hypoxemia, but ECMO did so to a greater degree, and only ECMO improved hypercarbia. Only NO decreased lymph flow, possibly as an effect of decreased microvascular filtration pressure. This study did not attempt to evaluate the impact of these interventions on ventilatory requirements, barotrauma, or outcome. However, this model suggests that NO therapy may moderate pulmonary hypertension and improve lymph flow in acute lung injury. Clinical studies are needed to assess whether NO therapy might be beneficial in treatment of severe acute lung injury in older children and adults.
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Critical care medicine · Nov 1997
Prediction of poor outcome of intensive care unit patients admitted from the emergency department.
To assess whether physicians can identify very low likelihood of survival and very low likelihood of favorable functional outcome in adult nontrauma patients before admission to the intensive care unit (ICU) from the emergency department (ED). ⋯ If a cutoff point of < 2% predicted survival is used in the triage of patients away from the ICU, the MPM0 has too low a sensitivity to be used as an effective screen. The low sensitivities and relatively low positive predictive values with wide confidence intervals of physician predictions of < 2% survival also preclude their use in triage. The addition of functional outcome as an end point improves the sensitivity, specificity, and positive predictive value of subjective predictions, making triage of patients away from the ICU at the time of ED evaluation a realistic possibility.
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Critical care medicine · Nov 1997
Early onset of acute pulmonary dysfunction after cardiovascular surgery: risk factors and clinical outcome.
To define the incidence, risk factors, and clinical outcome of early pulmonary dysfunction after cardiovascular surgery for adults. ⋯ The incidence of early postoperative pulmonary dysfunction is uncommon; however, once developed, it is associated with increased morbidity and mortality after cardiovascular surgery. Advanced age, large body mass index, preoperative increased pulmonary arterial pressure, low stroke volume index, hypoalbuminemia, history of cerebral vascular disease, emergency surgery, and prolonged cardiopulmonary bypass time are risk factors for early onset of severe pulmonary dysfunction after surgery. Postoperative hematocrit and systemic hemodynamics suggest that early postoperative pulmonary dysfunction can be a component of a generalized inflammatory reaction to cardiovascular surgery.
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Critical care medicine · Nov 1997
Comparative StudyImproved oxygenation by nitric oxide is enhanced by prior lung reaeration with surfactant, rather than positive end-expiratory pressure, in lung-lavaged rabbits.
The inhalation of nitric oxide increases oxygenation by improving the ventilation/perfusion ratios in neonates with respiratory distress syndrome and those ratios in adults with acute respiratory distress syndrome. There is evidence that inhaled nitric oxide is ineffective when the lung remains atelectatic and poorly inflated. This study aimed to enhance nitric oxide delivery by improving lung aeration by means of exogenous surfactant or by increasing positive end-expiratory pressure. ⋯ These data indicate that inhaled nitric oxide is able to improve arterial oxygenation after alveolar recruitment by means of a low dose of exogenous surfactant, and not by increase of positive end-expiratory pressure from 6 to 10 cm H2O, in lung-lavaged rabbits.