Effect of Delirium on Physical Function in Noncardiac Thoracic Surgery Patients

Abstract

Background The effect of delirium on physical function in patients undergoing noncardiac thoracic surgery has not been well described and may differ from that in other surgical populations. Objective To determine the effects of delirium on muscle strength and functional independence. The primary end point was change in Medical Research Council sum score (MRC-SS) by delirium status. Methods A secondary analysis of data from a clinical trial involving English-speaking adults aged 18 years or older who were undergoing major noncardiac thoracic surgery. Exclusion criteria were history of schizophrenia, Parkinson disease, dementia, alcohol abuse, or neuroleptic malignant syndrome; haloperidol allergy; being pregnant or nursing; QT prolongation; and taking levodopa or cholinesterase inhibitors. Delirium was assessed twice daily using the Confusion Assessment Method for the Intensive Care Unit. Preoperatively and postoperatively, muscle strength was assessed using the modified MRC-SS and functional independence was assessed using the Katz scale of activities of daily living. Changes in MRC-SS and Katz score by delirium status were analyzed using the Fisher exact test. Results Seventy-three patients were included in the analysis. Median (interquartile range) MRC-SS and Katz score before surgery did not differ significantly between patients without and with delirium (MRC-SS: 30 [30-30] vs 30 [30-30], P > .99; Katz score: 6 [6-6] vs 6 [6-6], P = .63). The percentage of patients with a change in MRC-SS was similar in patients without and with delirium (17% vs 13%, respectively; P > .99). More patients in the delirium group had a change in Katz score (13% vs 0%, P = .04). Conclusions Postoperative delirium was not associated with change in muscle strength. Follow-up studies using other muscle measures may be needed.

A Core Outcome Set for Research Evaluating Interventions to Prevent and/or Treat Delirium in Critically Ill Adults: An International Consensus Study (Del-COrS)

“…Similarly, the relationship between delirium and outcomes measuring patient emotional distress is well documented (30). The relationship between delirium and physical functioning, however, is less clear (31) and may have contributed to the decision to incorporate outcomes related to physical functioning into the outcome "health-related quality of life. "…”