How Should We Assess Neuropsychological Sequelae of Critical Illness?

Abstract

Critically ill, mechanically ventilated patients in the intensive care unit (ICU) consume a considerable proportion of our medical resources [1]. Patients admitted to an ICU with life-threatening critical illness require invasive procedures, mechanical ventilation, and sedative and analgesic drugs. Sedative and analgesic drugs in conjunction with mechanical ventilation and pain may adversely affect patients’ cognitive and emotional outcome following ICU care [2]. The patient’s distressing memories of the ICU experience may lead to psychotic symptoms such as hallucinations and delirium [3]. Most outcome studies have focused on survival as the major ICU outcome variable. More recent studies have found large proportions of ICU patients experience impaired health-related quality of life (HRQL) and psychosocial impairments [1,4]. Forty percent of ICU survivors were unable to return to work due to impaired physical and psychosocial problems [5]. Although medical outcomes research has studied critically ill patients, relatively few studies have assessed neuropsychological function. For example, outcomes research following acute respiratory distress syndrome (ARDS) has been ongoing for a number of years, however, only limited information exists concerning ultimate outcomes. Initial outcome studies assessed survival [6] and pulmonary function [7,8]. Subsequent studies have found impaired health status [8] and symptoms of posttraumatic stress disorder following ARDS [9]. Only in the past several years have a few studies assessed neuropsychological outcome following ARDS [10,11,12]. The limited studies of neuropsychological outcome following critical illness maybe due in part to the behef held by many physicians that most medical disorders have little effect on the brain and cognitive function [13].