Seminars in respiratory and critical care medicine
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Semin Respir Crit Care Med · Jun 2001
Ventilator-associated pneumonia complicating the acute respiratory distress syndrome.
Pulmonary infections span a wide spectrum, ranging from self-limited processes (e.g., tracheobronchitis) to life-threatening infections including both community-acquired pneumonia (CAP) and hospital-acquired pneumonia (HAP). Together, pneumonia and influenza rank as the sixth leading cause of death in the United States and lead all other infectious diseases in this respect. Pneumonia is the second-most-common hospital-acquired infection in the United States, accounting for 17.8% of all hospital-acquired infections and 40,000 to 70,000 deaths per year. ⋯ The greater hospital mortality associated with these "high-risk'' pathogens has been attributed to the virulence of these bacteria and the increased occurrence of inadequate initial antibiotic treatment of VAP due to the presence of antibiotic resistance. This review provides an overview of the clinical importance of VAP. We then describe how this nosocomial infection influences the management and outcomes of patients with the acute respiratory distress syndrome (ARDS).
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Semin Respir Crit Care Med · Jun 2001
Pulmonary and extrapulmonary forms of acute respiratory distress syndrome.
Acute respiratory distress syndrome (ARDS) is usually viewed as the functional and morphological expression of a similar underlying lung injury caused by a variety of insults. However, the distinction between ARDS due to a direct (ARDSp) versus an indirect (ARDSexp) lung injury is gaining more attention as a means of better comprehending the pathophysiology of ARDS and for modifying ventilatory management. ⋯ It is possible that the two insults may coexist (i.e., one lung with direct injury (as in pneumonia) and the other with indirect injury, through mediator release from the contralateral pneumonia); (2) the radiological pattern, by chest x-ray or computed tomography (CT), is different in ARDSp (characterized by prominent consolidation) and ARDSexp (characterized by prominent ground-glass opacification); (3) in ARDSp lung elastance is more markedly increased than in ARDSexp, where the main abnormality is the increase in chest wall elastance, due to abnormally high intra-abdominal pressure; (4) positive end-expiratory pressure (PEEP), inspiratory recruitment, and prone position are more effective to improve respiratory mechanics, alveolar recruitment, and gas-exchange in ARDSexp. Further studies are warranted to better define if the distinction between ARDS of different origins can improve clinical management and survival.
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Semin Respir Crit Care Med · Jan 2001
Monitoring sedation, agitation, analgesia, neuromuscular blockade, and delirium in adult ICU patients.
Preliminary evidence suggests that closely monitoring sedation may have a positive effect on patient outcomes, including reductions in intensive care unit (ICU) stay, duration of mechanical ventilatory support, and number of diagnostic tests requested to assess central nervous system function. In the last few years, subjective instruments to assess agitation and sedation have been developed and tested for reliability and validity, including the Sedation-Agitation Scale and the Motor Activity Assessment Scale. ⋯ Promising techniques for objective assessment of sedation (such as the bispectral index) and strategies to guide neuromuscular blockade with train-of-four (TOF) or clinical exam monitoring have emerged. Future efforts should focus on evaluating the impact of these monitoring techniques on specific outcomes in an effort to improve patient comfort, minimize adverse events, and reduce resource consumption.
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Current choices for sustained sedation in the critically ill include the benzodiazepines, the opiates, and propofol. Each of these groups of medications has their particular benefits: benzodiazepines provide the greatest amnesia, opiates are the only agents to provide analgesia, and propofol is the most easily titratable and the least likely to excessively accrue. ⋯ Further research is needed to determine the role of dexmedetomidine in the ICU. The emerging standard of care for sustained sedation is the use of standardized protocols, formulated with the help of clinical practice guidelines, and titrated with the guidance of sedation monitoring.
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Semin Respir Crit Care Med · Jan 2001
Models of critical care delivery: physician staffing in the ICU.
Although a consensus has emerged over the value of intensive care units (ICUs) in improving both the outcome and efficiency of critical care, the optimal staffing configuration of physicians who provide this care remains controversial. The value of open ICUs, where many clinicians can admit and care for patients, versus closed ICUs, where an on-site intensivist or housestaff team (or both) provides primary care of the critically ill patient is one aspect of this controversy. The roles of the intensivist, the ICU housestaff team, and the ICU director have also been debated. This article reviews the available literature on physician staffing in critical care units and its relationship to outcome and cost-effectiveness of care.