title: Preoperative laboratory testing in patients undergoing elective, low-risk ambulatory surgery.
abstract: BACKGROUND
  Routine preoperative laboratory testing for ambulatory surgery is not recommended.
  
  
  METHODS
  Patients who underwent elective hernia repair (N = 73,596) were identified from the National Surgical Quality Improvement Program (NSQIP) database (2005-2010). Patterns of preoperative testing were examined. Multivariate analyses were used to identify factors associated with testing and postoperative complications.
  
  
  RESULTS
  A total of 46,977 (63.8%) patients underwent testing, with at least one abnormal test recorded in 61.6% of patients. In patients with no NSQIP comorbidities (N = 25,149) and no clear indication for testing, 54% received at least one test. In addition, 15.3% of tested patients underwent laboratory testing the day of the operation. In this group, surgery was done despite abnormal results in 61.6% of same day tests. In multivariate analyses, testing was associated with older age, ASA (American Society of Anesthesiologists) class >1, hypertension, ascites, bleeding disorders, systemic steroids, and laparoscopic procedures. Major complications (reintubation, pulmonary embolus, stroke, renal failure, coma, cardiac arrest, myocardial infarction, septic shock, bleeding, or death) occurred in 0.3% of patients. After adjusting for patient and procedure characteristics, neither testing nor abnormal results were associated with postoperative complications.
  
  
  CONCLUSIONS
  Preoperative testing is overused in patients undergoing low-risk, ambulatory surgery. Neither testing nor abnormal results were associated with postoperative outcomes. On the basis of high rates of testing in healthy patients, physician and/or facility preference and not only patient condition currently dictate use. Involvement from surgical societies is necessary to establish guidelines for preoperative testing.
authors.affiliation: Department of Surgery, University of Texas Medical Branch, Galveston, TX 77555, USA.
authors.forename: Jaime
authors.initials: J
authors.lastname: Benarroch-Gampel
authors.forename: Kristin M
authors.initials: KM
authors.lastname: Sheffield
authors.forename: Casey B
authors.initials: CB
authors.lastname: Duncan
authors.forename: Kimberly M
authors.initials: KM
authors.lastname: Brown
authors.forename: Yimei
authors.initials: Y
authors.lastname: Han
authors.forename: Courtney M
authors.initials: CM
authors.lastname: Townsend
authors.forename: Taylor S
authors.initials: TS
authors.lastname: Riall
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000556:Ambulatory Surgical Procedures; D019411:Clinical Laboratory Techniques / Q000706:statistics & numerical data*; D015331:Cohort Studies; D016208:Databases, Factual; D017558:Elective Surgical Procedures; D005260:Female; D006300:Health Services Misuse / Q000706:statistics & numerical data*; D059685:Herniorrhaphy; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011183:Postoperative Complications / Q000453:epidemiology; D017410:Practice Guidelines as Topic; D011300:Preoperative Care / Q000379:methods* / Q000706:statistics & numerical data; D058996:Quality Improvement; D012306:Risk; D014481:United States; D055815:Young Adult