Influence of physical restraint on delirium of adult patients in ICU: A nested case–control study

Aims and objectives To investigate the impact of physical restraint on delirium of adult patients in intensive care unit. Background Delirium is a common clinical syndrome in intensive care unit, correlated with various adverse clinical outcomes. Physical restraint is a precipitating factor for delirium; however, the effect of physical restraint on delirium, such as duration, number and appliance is still unclear. Design A nested case–control study. Methods A cohort of 593 intensive care unit patients were observed for 12 months, and 447 of them who received physical restraint were included for analysis. Delirium was assessed using the Confusion Assessment Method for the intensive care unit. During hospitalisation in intensive care unit, newly‐onset delirium patients (the delirium group), and nondelirium patients of similar age, same gender, and conditions of mechanical ventilation and sedative drug usage (the nondelirium group) were included as the matching criteria. Patient data were acquired by reviewing medical and nursing electronic records. Results Among the 447 patients that had been physically restrained, 178 (39.8%) developed delirium. Delirium risk in patients with restraint ≥6 days was 26.30 times higher than in those <6 days. Patients who had two and three times of restraint had a 2.38‐fold and 3.62‐fold higher risk of delirium than those with one time of restraint. However, the appliance, site, time to apply and remove restraint had no effect on the incidence of delirium. Conclusions The incidence of delirium is high when patients use physical restraint. Duration and number of restraint are positively related to delirium. Restrictions on the use of restraint in intensive care unit are required to reduce the occurrence of delirium. Relevance to clinical practice To reduce delirium risk of patients in intensive care unit, nurses need to assess the risk of physical restraint and consider alternative measures, thereby to achieve the minimisation of the use of restraint.