Risk factors for agitation in critically ill patients

OBJECTIVE: To evaluate the incidence of agitation in the first 7 days after intensive care unit admission, its risk factors and its associations with clinical outcomes. METHODS: This single-center prospective cohort study included all patients older than 18 years with a predicted stay > 48 hours within the first 24 hours of intensive care unit admission. Agitation was defined as a Richmond Agitation Sedation Scale score ≥ +2, an episode of agitation or the use of a specific medication recorded in patient charts. RESULTS: Agitation occurred in 31.8% of the 113 patients. Multivariate analysis showed that delirium [OR = 24.14; CI95% 5.15 - 113.14; p < 0.001], moderate or severe pain [OR = 5.74; CI95% 1.73 - 19.10; p = 0.004], mechanical ventilation [OR = 10.14; CI95% 2.93 - 35.10; p < 0.001], and smoking habits [OR = 4.49; CI95% 1.33 - 15.17; p = 0.015] were independent factors for agitation, while hyperlactatemia was associated with a lower risk [OR = 0.169; CI95% 0.04 - 0.77; p = 0.021]. Agitated patients had fewer mechanical ventilation-free days at day 7 (p = 0.003). CONCLUSION: The incidence of agitation in the first 7 days after admission to the intensive care unit was high. Delirium, moderate/severe pain, mechanical ventilation, and smoking habits were independent risk factors. Agitated patients had fewer ventilator-free days in the first 7 days.