Chest
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Pulmonary embolism (PE) is common, and diagnosis is often difficult. Investigation has traditionally required expensive imaging procedures that are frequently nondiagnostic. Consequently, current practice favors noninvasive diagnosis of PE using algorithms combining risk assessment and d-dimer. Despite the proven safety of this approach, concern persists about such strategies to exclude PE, largely due to variable d-dimer sensitivity. The aim of this study was to prospectively assess the safety of a new algorithm combining a novel, rapid d-dimer test (IL Test; Instrumentation Laboratory; Lexington, MA), Pa(O2) measurement, and risk factor assessment in excluding PE in subjects presenting to an acute care setting. ⋯ The latex-enhanced immunoassay d-dimer and normal arterial oxygen pressure levels can safely exclude PE in a low-risk population presenting to an acute care setting. While these results cannot be extrapolated to all patients with suspected PE, they do confirm the safety of this approach in a population with a low underlying risk of PE.
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To examine the relationship between myocardial injury, assessed by cardiac troponin I (cTnI) levels, and outcome in selected critically ill patients without acute coronary syndromes or cardiac dysfunction. ⋯ This study demonstrates the high frequency of myocardial injury (32%) in critically ill patients without acute coronary syndromes or cardiac dysfunction on admission to ICU. Myocardial injury is an independent determinant of hospital mortality. Assessment of myocardial injury on admission to ICU would make it possible to identify patients at increased risk of death.
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While most patients with sleep-disordered breathing are treated with continuous positive airway pressure (CPAP), bilevel positive airway pressure (BLPAP) is often used. Having observed that BLPAP therapy increased central apneas in some of our patients undergoing sleep studies, we conducted this study to evaluate the effects of BLPAP. ⋯ BLPAP often increases the frequency of CSR and non-CSR central apneas during sleep. Since CSR has adverse effects on cardiac function and sleep, it is important to consider this possible adverse effect of BLPAP.
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To evaluate the effects of spontaneous breathing at ambient airway pressure (Paw) and during airway pressure release ventilation (APRV) on respiratory work and respiratory muscle blood flow (RMBF) in experimental lung injury. ⋯ Respiratory work and RMBF are increased in acute lung injury when subjects breathe spontaneously at ambient Paw. Supporting spontaneous breathing with APRV decreases respiratory work and RMBF to physiologic values.