title: Hospitalization costs of total knee arthroplasty with a continuous femoral nerve block provided only in the hospital versus on an ambulatory basis: a retrospective, case-control, cost-minimization analysis.
abstract: OBJECTIVE
  After total knee arthroplasty (TKA), hospitalization may be shortened by allowing patients to return home with a continuous femoral nerve block (CFNB). This study quantified the hospitalization costs for 10 TKA patients receiving ambulatory CFNB versus a matched cohort of 10 patients who received CFNB only during hospitalization.
  
  
  METHODS
  We examined the medical records (n = 125) of patients who underwent a unilateral, primary, tricompartment TKA with a postoperative CFNB by 1 surgeon at one institution in an 18-month period beginning January 2004. Each of the 10 patients discharged home with an ambulatory CFNB (cases) was matched with a patient with a hospital-only CFNB (controls) for age, gender, body mass index, and health status. Financial data were extracted from the hospital microcosting database.
  
  
  RESULTS
  Nine patients with ambulatory CFNB (cases) were discharged home on postoperative day (POD) 1 and 1 on POD 4. Of the controls, 3 were discharged home on POD 3, 6 on POD 4, and 1 on POD 5. The median (range) costs of hospitalization (excluding implant and professional fees) was US dollars 5,292 (US dollars 4,326-US dollars 7,929) for ambulatory cases compared with US dollars 7,974 (US dollars 6,931-US dollars 9,979) for inpatient controls (difference = US dollars 2,682, 34% decrease, P < .001). The total charges for hospitalization, the implant, and professional fees was US dollars 33,646 (US dollars 31,816-US dollars 38,468) for cases compared with US dollars 39,100 (US dollars 36,096-US dollars 44,098) for controls (difference = US dollars 5,454, 14% decrease, P < .001).
  
  
  CONCLUSIONS
  This study provides evidence that ambulatory CFNB for selected patients undergoing TKA has the potential to reduce hospital length of stay and associated costs and charges. However, the current study has significant inherent limitations based on the study design. Additional research is required to replicate these results in a prospective, randomized, controlled trial and to determine whether any savings exceed additional CFNB costs such as from complications, having caregivers provide care at home, and additional hospital/health care provider visits.
authors.affiliation: Department of Anesthesiology, University of California San Diego, San Diego, CA, USA. bilfeld@ucsd.edu
authors.forename: Brian M
authors.initials: BM
authors.lastname: Ilfeld
authors.forename: Edward R
authors.initials: ER
authors.lastname: Mariano
authors.forename: Brian A
authors.initials: BA
authors.lastname: Williams
authors.forename: Jennifer N
authors.initials: JN
authors.lastname: Woodard
authors.forename: Alex
authors.initials: A
authors.lastname: Macario
mesh_terms: D000368:Aged; D000553:Ambulatory Care / Q000191:economics*; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000627:therapeutic use; D019645:Arthroplasty, Replacement, Knee / Q000191:economics*; D016022:Case-Control Studies; D003361:Cost Allocation; D003363:Cost Control; D023381:Endpoint Determination; D005260:Female; D005267:Femoral Nerve; D006760:Hospitalization / Q000191:economics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009407:Nerve Block; D010098:Oxycodone / Q000008:administration & dosage / Q000627:therapeutic use; D012189:Retrospective Studies; D018401:Sample Size; D016896:Treatment Outcome
chemical_list: D000701:Analgesics, Opioid; D010098:Oxycodone