Epidural analgesia does not increase the rate of inpatient falls after major upper abdominal and thoracic surgery: a retrospective case-control study

Postoperative epidural analgesia for major upper abdominal and thoracic surgery can provide significant benefits, including superior analgesia and reduced pulmonary dysfunction. Nevertheless, epidural analgesia may also be associated with decreased muscle strength, sympathetic tone, and proprioception that could possibly contribute to falls. The purpose of this retrospective case-control study was to search a large national database in order to investigate the possible relationship between postoperative epidural analgesia and the rate of inpatient falls.

Data from the nationwide inpatient sample for 2007-2011 were queried for adult patients who underwent elective major upper abdominal and thoracic surgery. Multiple International Classification of Diseases, Ninth Revision, Clinical Modification codes for inpatient falls and accidents were combined into one binary variable. Univariate analyses were used for initial statistical analysis. Logistic regression analyses and McNemar’s tests were subsequently used to investigate the association of epidural analgesia with inpatient falls in a 1:1 case-control propensity-matched sample after adjustment of patients’ demographics, comorbidities, and hospital characteristics.

Forty-two thousand six hundred fifty-eight thoracic and 54,974 upper abdominal surgical procedures were identified. The overall incidence of inpatient falls in the thoracic surgery group was 6.54% with an increasing trend over the study period from 4.95% in 2007 to 8.11% in 2011 (P < 0.001). Similarly, the overall incidence of inpatient falls in the upper abdominal surgery group was 5.30% with an increasing trend from 4.55% in 2007 to 6.07% in 2011 (P < 0.001). Postoperative epidural analgesia was not associated with an increased risk for postoperative inpatient falls in the thoracic surgery group (relative risk [RR], 1.18; 95% confidence interval [CI], 0.95 to 1.47; P = 0.144) and in the upper abdominal surgery group (RR, 0.84; 95% CI 0.64 to 1.09; P = 0.220). Inpatient falls compared with non-falls were associated with a longer median (interquartile range) length of hospital stay in both the thoracic surgery group (11 [7-17] days vs 9 [6-16] days, respectively; P < 0.001) and the upper abdominal surgery group (12 [7-20] days vs 10 [6-17] days, respectively; P < 0.001).

Our study suggests that postoperative epidural analgesia for patients undergoing major upper abdominal and thoracic surgery is not associated with an increased risk of inpatient falls.