In summary, ICU psychosis does not develop in all patients. Instead, many patients are at risk for hypoactive, hyperactive, or mixed hypoactive and hyperactive delirium. Prevention of delirium should always be foremost, including recognition of patients at high risk, minimal use of causative medications, and treatment of physiological conditions that are often unrelated to a patient's admitting diagnosis. When prevention fails, early diagnosis and treatment can make a marked difference in patients' outcomes. The potential adverse outcomes of delirium are well documented. These include increased mortality; increased length of stay; reduced level of functioning in the elderly, which often leads to placement in a nursing home; and stress response syndrome after hospitalization. The value of nursing in preventing delirium is evident when nurses apply their knowledge of potential causes and develop strategies to avoid these causes in their patients. Nurses provide early detection and coordinate with other members of the healthcare team to initiate a plan of care that includes prompt treatment of delirium to reduce the signs and symptoms, duration, and potential adverse sequelae of this disorder. Nursing interventions are designed to enhance patients' cognitive status, sense of security, safety, and comfort. Nurses are instrumental in providing appropriate choices, doses, and administration of medications and in recognizing side effects. Use of medications ordered to treat delirium is often left to nurses' discretion because the orders specify that the drugs should be given as needed. Finally, nurses are the ones who recognize the need for additional assistance via psychiatric consultations or for more intensive observation and management of patients to ensure quality care.