Predictors of agitation in critically ill adults

Background: Agitation in critically ill adults is a frequent complication of hospitalization and results in multiple adverse outcomes. Potential causes of agitation are numerous; however, data on factors predictive of agitation are limited. Objectives: To identify predictors of agitation by examining demographic and clinical characteristics of critically ill patients. Methods: A medical record review was performed. Documentation of agitation was indicated by scores on the Richmond Agitation-Sedation Scale or the use of an agitation keyword. Records of 200 patients from 1 medical and 1 surgical intensive care unit were used for the study. Risk factors were determined for 2 points in time: admission to the intensive care unit and within 24 hours before the first episode of agitation. Data on baseline demographics, preadmission risk factors, and clinical data were collected and were evaluated by using logistic multivariable regression to determine predictors of agitation. Results: Predictors of agitation on admission to intensive care were history of use of illicit substances, height, respiratory and central nervous system subscores on the Sequential Organ Failure Assessment, and use of restraints. Predictors of agitation within 24 hours before the onset of agitation were history of psychiatric diagnosis, height, score on the Sequential Organ Failure Assessment, ratio of PaO2 to fraction of inspired oxygen less than 200, serum pH, percentage of hours with restraints, percentage of hours of mechanical ventilation, pain, and presence of genitourinary catheters. Conclusions: Predictors of agitation on admission and within 24 hours before the onset of agitation were primarily clinical variables.