Critical care medicine
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Critical care medicine · Mar 2015
Influence of Inspiration to Expiration Ratio on Cyclic Recruitment and Derecruitment of Atelectasis in a Saline Lavage Model of Acute Respiratory Distress Syndrome.
Cyclic recruitment and derecruitment of atelectasis can occur during mechanical ventilation, especially in injured lungs. Experimentally, cyclic recruitment and derecruitment can be quantified by respiration-dependent changes in PaO2 (ΔPaO2), reflecting the varying intrapulmonary shunt fraction within the respiratory cycle. This study investigated the effect of inspiration to expiration ratio upon ΔPaO2 and Horowitz index. ⋯ Inverse ratio ventilation minimizes cyclic recruitment and derecruitment of atelectasis in an experimental model of surfactant-depleted pigs. Time constants for recruitment and derecruitment, and regional ventilation distribution, reflect these findings and highlight the time dependency of cyclic recruitment and derecruitment.
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Critical care medicine · Mar 2015
Extravascular Lung Water and Pulmonary Vascular Permeability Index as Markers Predictive of Postoperative Acute Respiratory Distress Syndrome: A Prospective Cohort Investigation.
Robust markers of subclinical perioperative lung injury are lacking. Extravascular lung water indexed to predicted body weight and pulmonary vascular permeability index are two promising early markers of lung edema. We aimed to evaluate whether extravascular lung water indexed to predicted body weight and pulmonary vascular permeability index would identify patients at risk for clinically significant postoperative pulmonary edema, particularly resulting from the acute respiratory distress syndrome. ⋯ Perioperative extravascular lung water indexed to predicted body weight is an early marker that predicts risk of clinically significant postoperative pulmonary edema in at-risk surgical patients. Pulmonary vascular permeability index effectively discriminated postoperative acute respiratory distress syndrome from cardiogenic pulmonary edema. These measures will aid in the early detection of subclinical lung injury in at-risk surgical populations.
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Critical care medicine · Mar 2015
Multicenter StudyMechanical Ventilation Management During Extracorporeal Membrane Oxygenation for Acute Respiratory Distress Syndrome: A Retrospective International Multicenter Study.
To describe mechanical ventilation settings in adult patients treated for an acute respiratory distress syndrome with extracorporeal membrane oxygenation and assess the potential impact of mechanical ventilation settings on ICU mortality. ⋯ Protective mechanical ventilation strategies were routinely used in high-volume extracorporeal membrane oxygenation centers. However, higher positive end-expiratory pressure levels during the first 3 days on extracorporeal membrane oxygenation support were independently associated with improved survival. Further prospective trials on the optimal mechanical ventilation strategy during extracorporeal membrane oxygenation support are warranted.
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Critical care medicine · Mar 2015
Reversible Increase in Maximal Cortisol Secretion Rate in Septic Shock.
Cortisol clearance is reduced in sepsis and may contribute to the development of impaired adrenocortical function that is thought to contribute to the pathophysiology of critical illness-related corticosteroid insufficiency. We sought to assess adrenocortical function using computer-assisted numerical modeling methodology to characterize and compare maximal cortisol secretion rate and free cortisol half-life in septic shock, sepsis, and healthy control subjects. ⋯ Results obtained by numerical modeling are consistent with comparable measures obtained by the gold standard stable isotope dilution method. Septic shock is associated with generally not only higher levels but also greater variance of maximal cortisol secretion rate when compared with control and sepsis groups. Additional studies would be needed to determine whether assessment of cortisol kinetic parameters such as maximal cortisol secretion rate and free cortisol half-life is useful in the diagnosis or management of critical illness-related corticosteroid insufficiency.
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Critical care medicine · Mar 2015
Risk Factors for and Prediction by Caregivers of Extubation Failure in ICU Patients: A Prospective Study.
The influence of delirium, ICU-acquired paresis, and cardiac performance on extubation outcome has never been evaluated together. We aimed to assess the respective role of these factors on the risk of extubation failure and to assess the predictive accuracy of caregivers. ⋯ An ineffective cough, a prior duration of mechanical ventilation more than 7 days, and severe systolic left ventricular dysfunction were stronger predictors of extubation failure than delirium or ICU-acquired weakness. Only one-third patients who required reintubation were considered at high risk for extubation failure by caregivers.