Critical care medicine
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Critical care medicine · Jun 1997
Oxalated pyridoxalated hemoglobin polyoxyethylene conjugate normalizes the hyperdynamic circulation in septic sheep.
Excessive production of nitric oxide significantly contributes to the hyperdynamic state associated with sepsis. The ability of hemoglobin to scavenge nitric oxide may therefore be beneficial in the treatment of sepsis. In this study, we determined the effects of different doses of the modified human pyridoxalated hemoglobin polyoxyethylene conjugate in an ovine model of hyperdynamic sepsis. ⋯ The infusion of low doses of pyridoxalated hemoglobin polyoxyethylene conjugate in septic sheep reverses the hyperdynamic circulatory state. An increase in pulmonary arterial pressure was the only observed hemodynamic side effect; changes in the structure or function of other organ systems, or their biochemical correlates were not investigated in this study. In addition to a possible nitric oxide scavenging effect, pyridoxalated hemoglobin polyoxyethylene may affect the nitric oxide synthase and endothelin systems.
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Critical care medicine · Jun 1997
Randomized Controlled Trial Clinical TrialOxygen transport patterns in patients with sepsis syndrome or septic shock: influence of treatment and relationship to outcome.
To investigate the relationship between oxygen transport patterns and outcome in patients with sepsis syndrome or septic shock managed according to two different treatment regimens. ⋯ Survivors of sepsis syndrome or septic shock are characterized by an ability to increase both DO2 and VO2. In contrast, nonsurvivors typically have reduced cardiac reserve, they fail to increase VO2 following resuscitation, and when delivery is enhanced with aggressive inotropic support, oxygen extraction falls. These patterns of response were similar in both treatment and control groups, although the magnitude of the changes was exaggerated in the treatment group. These observations may help to explain the findings by some investigators that treatment aimed at achieving survivor values of cardiac index, DO2, and VO2 fails to improve outcome when instituted following admission to intensive care.
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Critical care medicine · Jun 1997
Randomized Controlled Trial Clinical TrialEffects of varying levels of positive end-expiratory pressure on intracranial pressure and cerebral perfusion pressure.
To determine the influence of positive end-expiratory pressure (PEEP) on intracranial pressure and cerebral perfusion pressure. ⋯ In patients with normal intracranial pressure, PEEP at 5 cm H2O did not significantly alter intracranial pressure. The clinical relevance of the intracranial pressure increase at PEEP levels of 10 and 15 cm H2O is questionable because cerebral perfusion pressure did not change and remained > 60 mm Hg. In patients with increased intracranial pressure, higher levels of PEEP did not significantly change intracranial pressure or cerebral perfusion pressure.
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Critical care medicine · Jun 1997
Measurements of total plasma nitrite and nitrate in pediatric patients with the systemic inflammatory response syndrome.
The systemic inflammatory response syndrome (SIRS) is typified by the presence of fever, hemodynamic changes, and end organ dysfunction. Endothelial cell activation leads to overproduction of nitric oxide, which results in sustained vasodilation and hypotension. This study was undertaken to determine the sensitivity, specificity, and positive and negative predictive values of plasma nitrite/nitrate measurements in identifying patients with clinical characteristics of SIRS, as defined by criteria based on physician diagnosis. ⋯ Clinical diagnosis of SIRS is strongly associated with increased total plasma nitrite/nitrate concentrations in pediatric patients in the pediatric ICU. Many patients with increased nitrite/nitrate concentrations have inflammation without having a clinical diagnosis of SIRS. Our data suggest that increased plasma nitrite/nitrate concentrations are the standard for identifying patients with inflammation in the pediatric ICU.
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Critical care medicine · Jun 1997
Clinical TrialHigh-frequency oscillatory ventilation for adult respiratory distress syndrome--a pilot study.
To evaluate the safety and effectiveness of high-frequency oscillatory ventilation using a protocol designed to recruit and maintain optimal lung volume in patients with severe adult respiratory distress syndrome (ARDS). ⋯ High-frequency oscillatory ventilation is both safe and effective in adult patients with severe ARDS failing conventional ventilation. A lung volume recruitment strategy during high-frequency oscillatory ventilation produced improved gas exchange without a compromise in DO2. These results are encouraging and support the need for a prospective, randomized trial of algorithm-controlled conventional ventilation vs. high-frequency oscillatory ventilation for adults with severe ARDS.