Preoperative severe hypoalbuminemia is associated with an increased risk of postoperative delirium in elderly patients: Results of a secondary analysis.

PURPOSE: To explore the association between the severity of preoperative hypoalbuminemia and the occurrence of postoperative delirium.

MATERIALS AND METHODS: This was a secondary analysis of the database from a previously conducted clinical trial. 700 elderly patients (age ≥65years) who were admitted to intensive care unit (ICU) after noncardiac surgery were included. Delirium was assessed with the Confusion Assessment Method for the ICU twice daily during the first 7days postoperatively. Other outcomes were also monitored. The relationship between preoperative albumin level and postoperative delirium were analyzed using a logistic regression model.

RESULTS: 111 of 700 patients (15.9%) developed postoperative delirium. When compared with normal albumin level (>40.0g/L), severe (≤30.0g/L: OR 2.727, 95% CI 1.283-5.797, P=0.009), but not mild (35.1-40.0g/L: OR 1.175, 95% CI 0.679-2.032, P=0.565) or moderate (30.1-35.0g/L: OR 1.674, 95% CI 0.897-3.122, P=0.105) hypoalbuminemia was associated with an increased risk of postoperative delirium. Preoperative severe hypoalbuminemia was also associated with prolonged mechanical ventilation, increased non-delirium complications, and prolonged ICU and hospital stay after surgery.

CONCLUSIONS: Preoperative severe hypoalbuminemia (≤30.0g/L) was associated with an increased risk of postoperative delirium and worse outcomes.

TRIAL REGISTRATION: Chinese Clinical Trial Registry, www.chictr.org.cn, ChiCTR-TRC-10000802.