title: Predictors of intraoperative testing in adults undergoing noncardiac surgery within a regional hospital system.
abstract: BACKGROUND
  The use of intraoperative testing is central to anesthesia practice, and point-of-care testing (POCT) is often used. Nevertheless, POCT is costly and its contribution to patient outcome is unknown. There is a lack of guidelines to describe which patients should undergo intraoperative testing or how results should be applied. As such, we undertook a historical cohort study evaluating intraoperative testing practices within our region where POCT is not used.
  
  
  METHODS
  In 2012, we obtained a random sample of 1,000 adult patients undergoing noncardiac surgery in three of our health system hospitals. Patient, surgical, and testing details were extracted, and the surgical procedures were categorized using the Johns Hopkins risk guidelines. Our primary outcome was the administration of at least one intraoperative test. We used a multivariable logistic regression model to identify factors associated with testing and described the time from ordering the tests to receiving the results using descriptive statistics.
  
  
  RESULTS
  Study results showed that 110/1,000 (11.0%) patients underwent 413 diagnostic tests. Complete blood count was the most commonly administered test (36.3%), and the mean (standard deviation) time to obtain all test results was 29.9 (19.9) min. High-risk procedures were associated with an odds ratio (OR) of 12.3 (95% confidence interval [CI], 8.3 to 18.2; P < 0.001). Other predictors of intraoperative testing included emergency surgery (OR, 3.8; 95% CI, 2.0 to 7.2; P < 0.001), number of comorbidities (OR, 1.1; 95% CI, 1.0 to 1.2; P = 0.03), and duration of surgery (OR, 2.3; 95% CI, 1.8 to 2.9; P < 0.001).
  
  
  CONCLUSIONS
  Intraoperative testing is common and more likely in patients undergoing high-risk surgical procedures. In a central laboratory system, there is substantial time from ordering the tests to receiving the results. The clinical impact of this delay is unknown. Further evaluation is required regarding the relationship between the time required for intraoperative test results and perioperative outcomes.
authors.affiliation: Departments of Anesthesia and Critical Care and Clinical Epidemiology and Biostatistics, Population Health Research Institute (PHRI), McMaster University, 2V9 - 1280 Main St. West, Hamilton, ON, L8S 4K1, Canada. jessicaspence13@gmail.com.
authors.forename: Jessica
authors.identifier: http://orcid.org/0000-0003-1267-9455
authors.initials: J
authors.lastname: Spence
authors.affiliation: Department of Anesthesia and Critical Care, McMaster University, Hamilton, ON, Canada.
authors.forename: Michael
authors.initials: M
authors.lastname: Troncone
authors.affiliation: Michael G. DeGroote School of Medicine, Faculty of Health Sciences, McMaster University, Hamilton, ON, Canada.
authors.forename: Steven
authors.initials: S
authors.lastname: Long
authors.affiliation: Division of Neurology, Department of Medicine, University of Toronto, Toronto, ON, Canada.
authors.forename: Velina
authors.initials: V
authors.lastname: Tzankova
authors.affiliation: Division of Internal Medicine, Department of Medicine, University of Toronto, Toronto, ON, Canada.
authors.forename: Susan
authors.initials: S
authors.lastname: Tran
authors.affiliation: Department of Anesthesia and Critical Care, McMaster University, Hamilton, ON, Canada.
authors.forename: Joshua
authors.initials: J
authors.lastname: Peachey
authors.affiliation: Departments of Anesthesia and Critical Care and Clinical Epidemiology and Biostatistics, Population Health Research Institute (PHRI), McMaster University, 2V9 - 1280 Main St. West, Hamilton, ON, L8S 4K1, Canada.
authors.forename: Yannick
authors.initials: Y
authors.lastname: LeManach
authors.affiliation: Department of Anesthesia and Critical Care, McMaster University, Hamilton, ON, Canada.
authors.forename: James
authors.initials: J
authors.lastname: Paul
mesh_terms: D000328:Adult; D000368:Aged; D000776:Anesthesiology / Q000379:methods*; D015331:Cohort Studies; D005260:Female; D006761:Hospitals; D006801:Humans; D007431:Intraoperative Complications / Q000517:prevention & control*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D015999:Multivariate Analysis; D061646:Operative Time; D017410:Practice Guidelines as Topic; D012189:Retrospective Studies; D012306:Risk; D013514:Surgical Procedures, Operative / Q000379:methods*; D013997:Time Factors