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AAOS Now

Published 4/1/2013
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Mary Ann Porucznik

Preventing Inpatient Falls after Total Joint Surgery

Use of nerve blocks associated with increased rate of falls

Despite the implementation of fall prevention programs, inpatient falls continue to occur and can result in significant morbidity. According to research presented yesterday, the use of nerve blocks in total joint arthroplasty leads to a higher rate of falls, especially for patients undergoing primary total knee arthroplasty (TKA).

“Patients who undergo total joint procedures on their lower extremities are encouraged to ambulate soon after surgery and often have a continuous peripheral nerve block in place postoperatively as part of a pain management plan,” noted presenter Brian A. Klatt, MD, of the department of orthopaedic surgery at the University of Pittsburgh. “But research on falls in total joint patients is scarce.”

Retrospective, case-controlled study
Dr. Klatt and his coauthors conducted a retrospective case-control study on patients who underwent primary and revision TKA and total hip arthroplasty (THA) at one institution (December 2007 through July 2011). Electronic medical records were used to collect demographic and procedure data, hospital costs, falls data, and length of stay. Statistical analysis was performed using univariate and multivariate logistic regression analysis.

A total of 7,093 consecutive patients (3,009 male, 4,084 female; mean age, 63.7 years) were analyzed. The fall rate was 1.85 percent (131 falls). Primary TKA patients had a higher fall rate than primary THA patients (2.8 percent versus 0.96 percent). Among patients who had revision surgery, however, the reverse was true: revision TKA patients had a lower fall rate than revision THA patients (0.76 percent versus 1.8 percent) (Fig.1).

Nearly two thirds (62 percent) of total falls occurred while the patient was toileting. No difference in fall rate was found for sex or race, but age was a significant fall predictor; geriatric patients (age 65 years or older) had a greater likelihood of falling (odds ratio [OR] 1.82, confidence interval [CI] 1.28–2.60, P = 0.001).

Use of nerve blocks
Continuous peripheral nerve blocks were used as part of a postoperative pain management protocol for 5,086 of the 7,093 patients. Lumbar plexus nerve blocks were used for procedures involving the hip, and sciatic, femoral, or both sciatic and femoral nerve blocks were used for knee procedures. The blocks were kept in place for a minimum of 24 hours after the procedure and were managed by an anesthesiologist.

After controlling for age and procedure, nerve blocks were found to be an independent predictor of falls (OR 1.86, CI 1.16–2.98, P = 0.01). Although nerve blocks did not affect fall rates in patients with primary THA (Pearson chi-squared = 0.39, P = 0.53), the number of falls among primary TKA patients who had nerve blocks was significantly higher than among those without nerve blocks (Pearson chi-squared = 12.89, P < 0.001).>

Be cautious
This retrospective study relied on standardized forms completed by the nursing staff at the time of the fall. Dr. Klatt also noted that no specific intervention was implemented during the study period, and that no control group was used. The large number of patients and the focus on total joint surgery, however, are strengths of the study.

“The interventions suggested by this study are to be cautious with the use of nerve blocks in postoperative total joints patients,” concluded Dr. Klatt. “Previous studies have found that preoperative education programs have a positive effect on lowering patient fall rates. It may be that increased education on the effects of the nerve blocks is needed for patients to fully understand their limitations in the immediate postoperative period.”

Dr. Klatt’s coauthors on Scientific Paper 098,“Use of Nerve Blocks After Total Joint Arthroplasty Leads to Increased Rate of Falls,” include Matthew Pigott, BS; Nicholas Farber, BS; Yihe Huang, BS; and Antonia F. Chen, MD, MBA.

Disclosure information: Dr. Klatt—SLACK Inc.; Saunders/Mosby-Elsevier Operative Techniques in Orthopaedics; Journal of Arthroplasty; AAHKS. Mr. Pigott—no information. Mr. Farber and Mr. Huang—no conflicts. Dr. Chen—Novo Nordisk; SLACK Inc.

Mary Ann Porucznik is managing editor of AAOS Now. She can be reached at porucznik@aaos.org