Does Preoperative Pharmacogenomic Testing of Patients Undergoing TKA Improve Postoperative Pain? A Randomized Trial.

BACKGROUND: Pharmacogenomics is an emerging and affordable tool that may improve postoperative pain control. One challenge to successful pain control is the large interindividual variability among analgesics in their efficacy and adverse drug events. Whether preoperative pharmacogenomic testing is worthwhile for patients undergoing TKA is unclear. QUESTIONS/PURPOSES: (1) Are the results of preoperative pharmacogenetic testing associated with lower postoperative pain scores as measured by the Overall Benefit of Analgesic Score (OBAS)? (2) Do the results of preoperative pharmacogenomic testing lead to less total opioids given? (3) Do the results of preoperative pharmacogenomic testing lead to changes in opioid prescribing patterns? METHODS: Participants of this randomized trial were enrolled from September 2018 through December 2021 if they were aged 18 to 80 years and were undergoing primary TKA under general anesthesia. Patients were excluded if they had chronic kidney disease, a history of chronic pain or narcotic use before surgery, or if they were undergoing robotic surgery. Preoperatively, patients completed pharmacogenomic testing (RightMed, OneOME) and a questionnaire and were randomly assigned to the experimental group or control group. Of 99 patients screened, 23 were excluded, one before randomization; 11 allocated patients in each group did not receive their allocated interventions for reasons such as surgery canceled, patients ultimately undergoing spinal anesthesia, and change in surgery plan. Another four patients in each group were excluded from the analysis because they were missing an OBAS report. This left 30 patients for analysis in the control group and 38 patients in the experimental group. The control and experimental groups were similar in age, gender, and race. Pharmacogenomic test results for patients in the experimental group were reviewed before surgery by a pharmacist, who recommended perioperative medications to the clinical team. A pharmacist also assessed for clinically relevant drug-gene interactions and recommended drug and dose selection according to guidelines from the Clinical Pharmacogenomics Implementation Consortium for each patient enrolled in the study. Patients were unaware of their pharmacogenomic results. Pharmacogenomic test results for patients in the control group were not reviewed before surgery; instead, standard perioperative medications were administered in adherence to our institutional care pathways. The OBAS (maximum 28 points) was the primary outcome measure, recorded 24 hours postoperatively. A two-sample t-test was used to compare the mean OBAS between groups. Secondary measures were the mean 24-hour pain score, total morphine milligram equivalent, and frequency of opioid use. Postoperatively, patients were assessed for pain with a VAS (range 0 to 10). Opioid use was recorded preoperatively, intraoperatively, in the postanesthesia care unit, and 24 hours after discharge from the postanesthesia care unit. Changes in perioperative opioid use based on pharmacogenomic testing were recorded, as were changes in prescription patterns for postoperative pain control. Preoperative characteristics were also compared between patients with and without various phenotypes ascertained from pharmacogenomic test results. RESULTS: The mean OBAS did not differ between groups (mean ± SD 4.7 ± 3.7 in the control group versus 4.2 ± 2.8 in the experimental group, mean difference 0.5 [95% CI -1.1 to 2.1]; p = 0.55). Total opioids given did not differ between groups or at any single perioperative timepoint (preoperative, intraoperative, or postoperative). We found no difference in opioid prescribing pattern. After adjusting for multiple comparisons, no difference was observed between the treatment and control groups in tramadol use (41% versus 71%, proportion difference 0.29 [95% CI 0.05 to 0.53]; nominal p = 0.02; adjusted p > 0.99). CONCLUSION: Routine use of pharmacogenomic testing for patients undergoing TKA did not lead to better pain control or decreased opioid consumption. Future studies might focus on at-risk populations, such as patients with chronic pain or those undergoing complex, painful surgical procedures, to test whether pharmacogenomic results might be beneficial in certain circumstances. LEVEL OF EVIDENCE: Level I, therapeutic study.

Dexmedetomidine-associated diabetes insipidus during skull base surgery in a pediatric patient.

Diabetes insipidus is characterized by polyuria due to an inability to auto-regulate water balance resulting in dangerous metabolic derangements. Intraoperative anesthetics have been increasingly identified as a cause of diabetes insipidus in adult patients; however, it is rare in pediatrics. We present a case of a 16-year-old male undergoing resection of a recurrent left juvenile nasopharyngeal angiofibroma who experienced intraoperative polyuria concerning diabetes insipidus. Urine output drastically decreased following discontinuation of dexmedetomidine with complete resolution within 24 h. We conclude that this case of transient diabetes insipidus was associated with dexmedetomidine administration.

Intraoperative fluid management and kidney transplantation outcomes: A retrospective cohort study.

BACKGROUND: Patients undergoing kidney transplantation traditionally receive liberal amounts of fluid during surgery. However, excessive fluids can lead to fluid overload and ileus. In this retrospective cohort study, we compared the effect of restrictive versus liberal fluid therapy on kidney transplantation outcomes. METHODS: Patients who underwent deceased-donor kidney transplantation at Mayo Clinic from January 2014 to March 2019 were included. Those who received <3 L of intravenous fluids intraoperatively were categorized as "restrictive;" those who received ≥3 L were categorized as "liberal." The primary outcome was incidence of delayed graft function (DGF). Secondary outcomes included length of stay, readmission within 30 days, time to return of bowel function, and incidence of postoperative complications. RESULTS: Of the 1171 patients included, 557 were in the restrictive group and 614 in the liberal group. The mean (SD) fluid intake was 2.17 (.54) L in the restrictive group and 3.67 (.68) L in the liberal group (P<.001). There was no difference in DGF (relative risk, 1.03; P = .56), length of stay (P = .34), readmission (P = .80), return of bowel function (P = .71), or other postoperative complications. CONCLUSIONS: Intraoperative restrictive fluid therapy during kidney transplantation was not associated with DGF or worse outcomes when compared with liberal fluid therapy.

Routine Type and Screens Are Unnecessary for Primary Total Hip and Knee Arthroplasties at an Academic Hospital.

BACKGROUND: Despite decreasing transfusion rates, routine type and screens are frequently used before primary total hip arthroplasty (THA) and total knee arthroplasty (TKA). The aims of this study were to characterize transfusion rates and identify any factors that affect the likelihood of transfusion to determine if it is safe to discontinue routine preoperative type and screens at an academic hospital. METHODS: A retrospective chart review was performed for all patients who underwent primary THA or TKA in 2019 at an academic institution by a fellowship-trained arthroplasty surgeon. Data on preoperative type and screens, transfusion rates, bleeding disorders, and anticoagulation status were obtained. Patients were considered to have a preoperative type and screen if it was performed within 30 days before surgery. RESULTS: Overall, 379 patients were included in the study. Of these, 210 underwent primary THA and 169 underwent primary TKA. Four patients received transfusions during their hospitalization for a cumulative transfusion rate of 1.06%. No patients received an intraoperative transfusion. One (0.59%) patient received a postoperative transfusion after TKA, and 3 (1.43%) patients received a postoperative transfusion after THA. The mean preoperative hemoglobin of the 4 transfused patients was 10.8 g/dL. CONCLUSIONS: In summary, performing a preoperative routine type and screen is likely unnecessary at academic medical centers. Consideration for obtaining a type and screen may include complex primary surgeries or when patients have preoperative hemoglobin of less than 11 g/dL. Ultimately, preoperative type and screen should be considered on a case-by-case basis using clinical judgment.

Tongue Tied after Shoulder Surgery: A Case Series and Literature Review.

This article presents three cases of cranial nerve palsy following shoulder surgery with general anesthesia in the beach chair position. All patients underwent preoperative ultrasound-guided interscalene nerve block. Two cases of postoperative hypoglossal and one case of combined hypoglossal and recurrent laryngeal nerve palsies (Tapia's syndrome) were identified. Through this case series, we provide a literature review identifying postoperative cranial nerve palsies in addition to the discussion of possible etiologies. We suggest that intraoperative patient positioning and/or airway instrumentation is most likely causative. We conclude that the beach chair position is a risk factor for postoperative hypoglossal nerve palsy and Tapia's syndrome.