Usefulness of Perioperative Laboratory Tests in Total Hip and Knee Arthroplasty: Are They Necessary for All Patients?

BACKGROUND: Laboratory studies are routinely obtained preoperatively and postoperatively for total hip arthroplasty (THA) and total knee arthroplasty (TKA). This study evaluates the necessity of routine, perioperative laboratory tests and identifies risk factors for laboratory-associated interventions. METHODS: This retrospective review evaluated 967 consecutive patients scheduled for primary, unilateral TKAs (n = 593) or THAs (n = 374) over an 18-month period at a single institution. Preoperative prothrombin time (PT) and International Normalized Ratio (INR), complete blood count (CBC), complete metabolic panel (CMP), and postoperative CBC and basic metabolic panel (BMP) were recorded along with any laboratory-associated intervention. Patient demographics and comorbidities identified risk factors for abnormal or actionable laboratory studies. RESULTS: Preoperatively, the actionable rates for PT/INR, CMP, and CBC were 0.3%, 1.4%, and 0.5%, respectively. Vascular, renal, and immunologic diseases were risk factors for an actionable CBC. Risk factors for an actionable CMP include cardiac arrhythmia and diabetes. There were no risk factors for an actionable PT/INR. Postoperatively, only 1.5% of BMPs and 1.5% of CBCs were actionable. Congestive heart failure, renal disease vascular disease, or history of cancer (P = .030) were risk factors for an actionable CBC. There were no risk factors for an actionable BMP. Patients with an abnormal preoperative lab were 2.4 times more likely to have an actionable postoperative lab. Patients with an actionable preoperative lab were 11.3 times more likely to have an actionable postoperative lab. CONCLUSION: Routine preoperative and postoperative labs may not be necessary on all patients undergoing a TKA or THA. Comorbid risk factors and abnormal or actionable preoperative CMPs and CBCs can help determine the usefulness of postoperative laboratory assessments.

Coagulation Laboratory Testing Is Predictive of Wound Complications Following Microdiscectomy.

STUDY DESIGN: Retrospective review. OBJECTIVE: To determine whether abnormal preoperative testing is associated with postoperative complications in patients undergoing a microdiscectomy. METHODS: Patients undergoing a microdiscectomy between 2006 and 2013 were identified in the National Surgical Quality Improvement Program database based on appropriate current procedural terminology coding. Thirty-day postoperative complications were analyzed in addition to patient demographics, comorbidities, and abnormal preoperative laboratory values. A series of over 650 univariate analyses to determine which independent variables to include for each complication were completed. Based on those analyses, 12 logistic regression models were built, one for each specific complication. Each model adjusted for age, gender, comorbidities, American Society of Anesthesiologists classification, as well as operative time. RESULTS: A total of 5947 patients undergoing a microdiscectomy were included in the study. Abnormal preoperative international normalized ratio (odds ratio [OR] = 5.85, P < .05) was associated with any wound infection, superficial or deep, and abnormal partial thromboplastin time was significantly associated with wound dehiscence (OR = 6.80, P < .05). Postoperative urinary tract infections were associated with abnormal preoperative hematocrit (OR = 8.00, P < .05). None of the identified preoperative labs were independently associated with pulmonary embolism, organ space surgical site infections, or intubation. CONCLUSIONS: Abnormal preoperative coagulation labs were significantly associated with postoperative wound complications. However, the majority of tests were not associated with adverse events following microdiscectomy. Further study is necessary to conclude whether these tests provide information that can modify perioperative management and whether widespread testing is cost-effective.

The utility of preoperative laboratories in predicting postoperative complications following posterolateral lumbar fusion.

BACKGROUND CONTEXT: Several studies have suggested that laboratory results have minimal impact on clinical decision making in surgery. Despite the widespread use of preoperative testing in spine surgery and the large volume of posterolateral lumbar fusions (PLFs) being performed each year, no study has assessed the ability of preoperative laboratories to predict adverse events following PLF. PURPOSE: The purpose of this study was to explore the relationship between commonly obtained preoperative laboratory results and postoperative complications following one- to two-level PLF. STUDY DESIGN: This is a retrospective study of prospectively collected data. PATIENT SAMPLE: The 2006-2013 American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was employed to identify all patients who underwent one- to two-level PLF. OUTCOME MEASURES: The outcome variables of interest were 30-day postoperative complications, which were assessed as major complications, minor adverse events, and total complications. MATERIALS AND METHODS: Demographics, comorbidities, and perioperative characteristics were collected for each patient. Preoperative laboratories included sodium, blood urea nitrogen, creatinine, albumin, bilirubin, serum glutamic oxaloacetic transaminase, alkaline phosphatase, white blood cell count, hematocrit, platelet count, prothrombin time, international normalized ratio, and partial thromboplastin time. Bivariate analysis and multivariate logistic regression modeling were used to explore the relationship between abnormal preoperative laboratories and the incidence of postoperative complications. RESULTS: After controlling for age, ASA score, length of surgery, and all significant comorbidities, abnormal sodium (odds ratio [OR]=2.47, 95% confidence interval [CI]: 1.45-4.19, p=.001) and abnormal INR (OR=2.33, 95% CI: 1.09-4.98, p=.029) were significantly associated with the development of any complication. Sodium (OR=1.61, 95% CI: 1.01-2.54, p=.04) and platelets (OR=1.58, 95% CI: 1.02-2.44, p=.04) were associated with minor complications. Meanwhile, creatinine (OR=1.74, 95% CI: 1.02-2.99, p=.04) and platelets (OR=1.71, 95% CI: 1.02-2.89, p=.04) were significant predictors of major adverse events. CONCLUSIONS: This study represents the first attempt to assess the utility of preoperative laboratories in predicting postoperative complications in PLF. Although the majority of laboratories were not significantly associated with adverse events, abnormal sodium values, INR, creatinine, and platelets were shown to be predictive of various complications.