Association between medication use and peri-operative delirium in older adult patients with hip fracture at King Chulalongkorn Memorial Hospital

Abstract

Background: Delirium is a common adverse consequence in the hip fracture population. Many medications can affect the emergence of the perioperative delirium but the data of older patients with hip fracture is lacking.

Objective: To investigate the association between the type and the number of medications and the occurrence of perioperative delirium in older patients with hip fracture.

Methods: This is a cross-sectional study which collected data from patients aged 65 years who underwent hip surgery at King Chulalongkorn Memorial Hospital. The Delirium Rating Scale-Revised-98-Thai version (DRS - R -98-T) was used to assess the delirium one day before the surgery, and the second day and the forth day after the surgery. Unpaired t - test, Pearson’s Chi-square test, and linear regression model were used to determine the association between different clinical variables.

Results: Forty patients (33.3%) of 120 older patients with hip fracture developed delirium during their hospital stay. Regarding the association between pre - operative medications and pre-operative delirium in linear regression model; benzodiazepine decreased DRS-R-98-T score (P = 0.004), beta-blocker decreased DRS-R-98-T score (P = 0.038), while antibiotic exposure increased DRS-R-98-T score (P = 0.035). Post-operative delirium was directly associated with exposure to antipsychotic drugs (pre- and post-operative use) (P = 0.045 and < 0.001 respectively) but inversely associated with benzodiazepines (pre - and post - operative use) (P = 0.04 and 0.024, respectively) and inversely associated with anticonvulsants (post-operative use) (P < 0.001). Age, dementia, gastrointestinal diseases, body mass index, history of life-time delirium, use of restraints, and history of blood transfusion were associated with increased DRS-R-98-T score.

Conclusion: Antibiotic exposure was associated with increased preoperative delirium, while benzodiazepines and beta blocker were associated with decreased preoperative delirium in older adults with hip fracture. Benzodiazepines and anticonvulsants might be inversely associated with postoperative delirium. The peri-operative delirium was not associated with the number of pre-hospital medications. These medications are modifiable factors for delirium prevention, so they should be cautiously used in older patients with hip fracture.