Critical care medicine
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Critical care medicine · Sep 2014
Mechanical Ventilation-Induced Intrathoracic Pressure Distribution and Heart-Lung Interactions.
Mechanical ventilation causes cyclic changes in the heart's preload and afterload, thereby influencing the circulation. However, our understanding of the exact physiology of this cardiopulmonary interaction is limited. We aimed to thoroughly determine airway pressure distribution, how this is influenced by tidal volume and chest compliance, and its interaction with the circulation in humans during mechanical ventilation. ⋯ Increased tidal volume and decreased chest wall compliance both increase the change in intrathoracic pressures and the value of the dynamic indices during mechanical ventilation. Additionally, the transmural pressure of the vena cava is decreased, whereas the transmural pressure of the right atrium is not changed.
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Critical care medicine · Sep 2014
Intra-Aortic Balloon Pump Effects on Macrocirculation and Microcirculation in Cardiogenic Shock Patients Supported by Venoarterial Extracorporeal Membrane Oxygenation.
This study was designed to assess the effects on macrocirculation and microcirculation of adding an intra-aortic balloon pump to peripheral venoarterial extracorporeal membrane oxygenation in patients with severe cardiogenic shock and little/no residual left ventricular ejection. ⋯ Restoring pulsatility and decreasing left ventricular afterload with intra-aortic balloon pump was associated with smaller left ventricular dimensions and lower pulmonary artery pressures but did not affect microcirculation variables in cardiogenic shock patients with little/no residual left ventricular ejection while on peripheral venoarterial extracorporeal membrane oxygenation.
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Critical care medicine · Sep 2014
Prevalence and Impact of Active and Passive Cigarette Smoking in Acute Respiratory Distress Syndrome.
Cigarette smoke exposure has recently been found to be associated with increased susceptibility to trauma- and transfusion-associated acute respiratory distress syndrome. We sought to determine 1) the incidence of cigarette smoke exposure in a diverse multicenter sample of acute respiratory distress syndrome patients and 2) whether cigarette smoke exposure is associated with severity of lung injury and mortality in acute respiratory distress syndrome. ⋯ In this first multicenter study of biomarker-determined cigarette smoke exposure in acute respiratory distress syndrome patients, we found that active cigarette smoke exposure was significantly more prevalent among acute respiratory distress syndrome patients compared to population averages. Despite their younger age, better overall health, and lower severity of illness, smokers by 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol had similar severity of lung injury as patients with undetectable 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol. These findings suggest that active cigarette smoking may increase susceptibility to acute respiratory distress syndrome in younger, healthier patients.
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Critical care medicine · Sep 2014
Circulating Immature Granulocytes With T-Cell Killing Functions Predict Sepsis Deterioration.
Primary objective was to identify leukocyte subsets that could predict the early evolution of sepsis at 48 hours (i.e., deterioration or stability/improvement). Secondary objectives were to evaluate the prognostic value of leukocyte subsets on mortality and immunosuppressive properties of immature granulocytes. ⋯ Circulating immature granulocytes predicted early sepsis deterioration and were enriched in myeloid-derived suppressor cells which could be responsible for immunosuppression through the induction of T-cell lymphopenia.
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Critical care medicine · Sep 2014
Gravity Predominates Over Ventilatory Pattern in the Prevention of Ventilator-Associated Pneumonia.
In the semirecumbent position, gravity-dependent dissemination of pathogens has been implicated in the pathogenesis of ventilator-associated pneumonia. We compared the preventive effects of a ventilatory strategy, aimed at decreasing pulmonary aspiration and enhancing mucus clearance versus the Trendelenburg position. ⋯ The Trendelenburg position predominates over expiratory flow bias and positive end-expiratory pressure in the prevention of gravity-dependent translocation of oropharyngeal pathogens and development of ventilator-associated pneumonia. These findings further substantiate the primary role of gravity in the pathogenesis of ventilator-associated pneumonia.