Despite the diagnostic and therapeutic advances that have occurred in medical practice over the past 3 decades, critically ill patients all too frequently develop complications that can result in increased morbidity, mortality, and cost of care. Among the most commonly encountered complications are venous thromboembolic disease (VTE), ventilator-associated pneumonia (VAP), catheterassociated infections (CAI), and stress-related mucosal disease (SRMD). Fortunately, clinicians have effective prophylactic strategies to prevent these complications in high-risk critically ill patients. Essential aspects of management for the critically ill patient should include knowledge of the risk factors for development, skill in recognition, and awareness of prevention strategies for the common complications of critical illness. In practical terms, the major obstacle has been failure to implement effective prophylactic strategies early enough in the "at-risk population" to achieve the beneficial effects on outcome. The best educational plan appears to be targeting the medical students and house staff, along with the intensive care unit nurses, pharmacists, and respiratory therapists. It is hoped that through education and the development of management protocols, morbidity and mortality will be improved for the critically ill patient.(Clin Pulm Med 2005;12: 258 -268) T he past 3 decades have produced tremendous advances in our understanding of disease processes, technological support, and improved diagnostic and therapeutic techniques.These advances have resulted in additional challenges for the care of the acutely ill patient. The challenge of caring for the critically ill patient includes diagnosis and treatment of the acute derangement that resulted in the intensive care unit (ICU) admission, continued management of the preexisting comorbid conditions, and the prevention of complications that frequently occur in the setting of critical illness. Common complications that are seen in the critically ill patient include venous thromboembolism (VTE), nosocomial infectious complications (ventilator-associated pneumonia ͓VAP͔, catheter-related bloodstream infections, etc), stress-related mucosal disease (SRMD), malnutrition, translocation of intestinal bacteria and/or endotoxin, critical illness polymyopathy and polyneuropathy, and single-and multiple-organ dysfunction/failure. Recognition of these potential complications has resulted in an increased implementation of prophylactic strategies in an attempt to reduce the incidence and adverse outcomes associated with these complications. There has been increased recognition of the importance of following recommendations and guidelines based on sound evidence from well-conducted clinical trials to achieve improved outcome. It has become clear that successful strategies for the care of the critically ill patient must incorporate a focus on prevention of common complications, as well as continued emphasis on treatment directed toward the acute process which mandated intensive care treatmen...