title: Inpatient falls after total knee arthroplasty: the role of anesthesia type and peripheral nerve blocks.
abstract: BACKGROUND
  Much controversy remains on the role of anesthesia technique and peripheral nerve blocks (PNBs) in inpatient falls (IFs) after orthopedic procedures. The aim of the study is to characterize cases of IFs, identify risk factors, and study the role of PNB and anesthesia technique in IF risk in total knee arthroplasty patients.
  
  
  METHODS
  The authors selected total knee arthroplasty patients from the national Premier Perspective database (Premier Inc., Charlotte, NC; 2006-2010; n = 191,570, >400 acute care hospitals). The primary outcome was IF. Patient- and healthcare system-related characteristics, anesthesia technique, and presence of PNB were determined for IF and non-IF patients. Independent risk factors for IFs were determined by using conventional and multilevel logistic regression.
  
  
  RESULTS
  Overall, IF incidence was 1.6% (n = 3,042). Distribution of anesthesia technique was 10.9% neuraxial, 12.9% combined neuraxial/general, and 76.2% general anesthesia. PNB was used in 12.1%. Patients suffering IFs were older (average age, 68.9 vs. 66.3 yr), had higher comorbidity burden (average Deyo index, 0.77 vs. 0.66), and had more major complications, including 30-day mortality (0.8 vs. 0.1%; all P < 0.001). Use of neuraxial anesthesia (IF incidence, 1.3%; n = 280) had lower adjusted odds of IF compared with adjusted odds of IF with the use of general anesthesia alone (IF incidence, 1.6%; n = 2,393): odds ratio, 0.70 (95% CI, 0.56-0.87). PNB was not significantly associated with IF (odds ratio, 0.85 [CI, 0.71-1.03]).
  
  
  CONCLUSIONS
  This study identifies several risk factors for IF in total knee arthroplasty patients. Contrary to common concerns, no association was found between PNB and IF. Further studies should determine the role of anesthesia practices in the context of fall-prevention programs.
authors.affiliation: From the Department of Anesthesiology, Hospital for Special Surgery, New York, New York (S.G.M., T.D., and O.S.); Department of Public Health, Division of Biostatistics and Epidemiology, Weill Cornell Medical College, New York, New York (R.R., J.P., and M.M.); Stony Brook University, Stony Brook, New York (P.G.); and Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, California (E.R.M.).
authors.forename: Stavros G
authors.initials: SG
authors.lastname: Memtsoudis
authors.forename: Thomas
authors.initials: T
authors.lastname: Danninger
authors.forename: Rehana
authors.initials: R
authors.lastname: Rasul
authors.forename: Jashvant
authors.initials: J
authors.lastname: Poeran
authors.forename: Philipp
authors.initials: P
authors.lastname: Gerner
authors.forename: Ottokar
authors.initials: O
authors.lastname: Stundner
authors.forename: Edward R
authors.initials: ER
authors.lastname: Mariano
authors.forename: Madhu
authors.initials: M
authors.lastname: Mazumdar
mesh_terms: D000058:Accidental Falls / Q000706:statistics & numerical data*; D000368:Aged; D000768:Anesthesia, General / Q000379:methods / Q000706:statistics & numerical data*; D019645:Arthroplasty, Replacement, Knee; D005260:Female; D006801:Humans; D007297:Inpatients / Q000706:statistics & numerical data*; D008297:Male; D009407:Nerve Block / Q000379:methods / Q000706:statistics & numerical data*; D016017:Odds Ratio; D061214:Patient Safety / Q000706:statistics & numerical data; D010525:Peripheral Nerves / Q000187:drug effects*; D012307:Risk Factors