Utility of Routine Preoperative Laboratory Testing for Low-risk Patients in Ambulatory Gynecologic Surgery.

STUDY OBJECTIVES: To examine the current use of routine preoperative laboratory testing in low-risk patients undergoing ambulatory gynecologic surgery and to determine if such testing affects surgical outcomes. DESIGN: The American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database was queried for ambulatory gynecologic surgeries between 2015 and 2018. Low-risk patients included in this study were defined as being American Society of Anesthesiologists class 1 or 2. The rate of preoperative laboratory testing before ambulatory gynecologic surgery in low-risk patients was determined and factors associated with testing including patient characteristics and comorbidities were evaluated. NSQIP-defined complications were compared between those with and without preoperative laboratory testing. Preoperative laboratory testing was defined as chemistry, hematology, coagulation, or liver function studies obtained within 30 days preoperatively. SETTING: National health systems that participate in the NSQIP. PATIENTS: There were 19 855 patients who underwent an ambulatory gynecologic procedure. INTERVENTIONS: Preoperative laboratory testing in low-risk patients before ambulatory gynecologic surgery. MEASUREMENTS AND MAIN RESULTS: Of the 19 855 patients studied, 14 258 (71.8%) received preoperative laboratory testing. Statistically significant differences were seen between patients who underwent preoperative testing and patients who did not. The most frequent preoperative test was a complete blood cell count (70.4%). Among patients who received preoperative testing, 4053 (28.4%) had at least 1 abnormal result. No statistically significant difference was seen in overall postoperative complication rate when comparing patients who received preoperative laboratory testing with those who did not (2.5% vs 2.2%, p = .30). Specifically, no statistically significant difference was seen among wound complications (1.0% vs 1.0%, p = .78), major complications (1.0% vs 0.8%, p = .11), unplanned return to the operating room (0.1% vs 0.2%, p = .40), unplanned readmission (0.7% vs 0.5%, p = .10), or overall morbidity (2.1% vs 1.9%, p = .38). Chi-square analyses were performed to compare categoric variables. Continuous variables were compared using unpaired t tests. CONCLUSION: This large study using a reputable national database revealed that despite updated evidence-based guidelines that recommend against the practice, preoperative laboratory testing continues to be performed for most low-risk patients undergoing ambulatory gynecologic surgery. This study also further supports current guidelines in demonstrating no difference in surgical outcomes between low-risk patients who did and did not receive preoperative laboratory testing. Preoperative laboratory testing practices for low-risk patients undergoing ambulatory gynecologic surgery do not follow current evidence-based guidelines and should be re-evaluated.

Rethinking the routine: Preoperative laboratory testing among American Society of Anesthesiologists class 1 and 2 patients before low-risk ambulatory surgery in the 2017 National Surgical Quality Improvement Program cohort.

BACKGROUND: Routine preoperative laboratory testing is not recommended for American Society of Anesthesiologists classification 1 or 2 patients before low-risk ambulatory surgery. METHODS: The 2017 National Surgical Quality Improvement Program data set was retrospectively queried for American Society of Anesthesiologists class 1 and 2 patients who underwent low-risk, elective outpatient anorectal, breast, endocrine, gynecologic, hernia, otolaryngology, oral-maxillofacial, orthopedic, plastic/reconstructive, urologic, and vascular operations. Preoperative laboratory testing was defined as any chemistry, hematology, coagulation, or liver function studies obtained ≤30 days preoperatively. Demographics, comorbidities, and outcomes were compared between those with and without testing. The numbers needed to test to prevent serious morbidity or any complication were calculated. Laboratory testing costs were estimated using Centers for Medicare and Medicaid Services data. RESULTS: Of 111,589 patients studied, 57,590 (51.6%) received preoperative laboratory testing; 26,709 (46.4%) had at least 1 abnormal result. Factors associated with receiving preoperative laboratory testing included increasing age, female sex, non-White race/ethnicity, American Society of Anesthesiologists class 2, diabetes, dyspnea, hypertension, obesity, and steroid use. Mortality did not differ between patients with and without testing. The complication rate was 2.5% among tested patients and 1.7% among patients without tests (P < .01). The numbers needed to test was 599 for serious morbidity and 133 for any complication. An estimated $373 million annually is spent on preoperative laboratory testing in this population. CONCLUSION: Despite American Society of Anesthesiologists guidelines, a majority of American Society of Anesthesiologists class 1 and 2 patients undergo preoperative laboratory testing before elective low-risk outpatient surgery. The differences in the rates of complications between patients with and without testing is low. Preoperative testing should be used more judiciously in this population, which may lead to cost savings.

Novel biomarkers to assess in utero effects of maternal opioid use: First steps toward understanding short- and long-term neurodevelopmental sequelae.

Maternal opioid use disorder is common, resulting in significant neonatal morbidity and cost. Currently, it is not possible to predict which opioid-exposed newborns will require pharmacotherapy for neonatal abstinence syndrome. Further, little is known regarding the effects of maternal opioid use disorder on the developing human brain. We hypothesized that novel methodologies utilizing fetal central nervous system-derived extracellular vesicles isolated from maternal blood can address these gaps in knowledge. Plasma from opioid users and controls between 9 and 21 weeks was precipitated and extracellular vesicles were isolated. Mu opioid and cannabinoid receptor levels were quantified. Label-free proteomics studies and unbiased small RNA next generation sequencing was performed in paired fetal brain tissue. Maternal opioid use disorder increased mu opioid receptor protein levels in extracellular vesicles independent of opioid equivalent dose. Moreover, cannabinoid receptor levels in extracellular vesicles were upregulated with opioid exposure indicating cross talk with endocannabinoids. Maternal opioid use disorder was associated with significant changes in extracellular vesicle protein cargo and fetal brain micro RNA expression, especially in male fetuses. Many of the altered cargo molecules and micro RNAs identified are associated with adverse clinical neurodevelopmental outcomes. Our data suggest that assays relying on extracellular vesicles isolated from maternal blood extracellular vesicles may provide information regarding fetal response to opioids in the setting of maternal opioid use disorder. Prospective clinical studies are needed to evaluate the association between extracellular vesicle biomarkers, risk of neonatal abstinence syndrome and neurodevelopmental outcomes.