Sepsis-Associated Delirium

Abstract

In Brief Sepsis is, in 27% to 55% of cases, complicated by a deterioration of mental status, which is consistent with delirium as consciousness, awareness, cognition, and behavior are preferentially affected. Electroencephalogram and somatosensory-evoked potentials are often abnormal, plasma levels of S-100b protein or neuron-specific enolase increased, and magnetic resonance imaging may show leukoencephalopathy. Pathophysiological mechanisms include cerebrovascular alteration, blood-brain barrier breakdown, inflammatory and metabolic factors, notably tumor necrosis factor-α, inducible NO synthase, and abnormal blood glucose levels. These processes may induce brain damage, stress oxidative-related cellular dysfunction, or apoptosis. In septic patients, mortality is increased with severity of delirium, degree of electrophysiological abnormalities, and neuron-specific enolase or S-100b plasma levels. The daily evaluation of patients with sepsis should systematically include appropriate delirium scores and, if delirium is present, laboratory investigations may help assess the potential damage to the brain. There is no specific treatment for sepsis associated delirium. Patient management is mainly based on controlling infection, organ system failure, and metabolic homeostasis, while avoiding neurotoxic drugs. Future therapies may target neuroinflammation, blood-brain barrier dysfunction, brain cell oxidative stress, or apoptosis. Sepsis is a devastating disorder that results in organ dysfunction and ultimately patients may die with multiple organ failure. The brain is commonly affected in sepsis and delirium, the main clinical presentation, usually parallels the severity of the inflammatory response to sepsis. Physicians should systematically screen for brain dysfunction in patients with sepsis.