Avis J. Thomas

Serum and Wound Vancomycin Levels After Intrawound Administration in Primary Total Joint Arthroplasty

BACKGROUND Periprosthetic joint infection is the most common cause of readmissions after total joint arthroplasty (TJA). Intrawound vancomycin powder (VP) has reduced infection rates in spine surgery; however, there are no data regarding VP in primary TJA. METHODS Thirty-four TJA patients received 2 g of VP intraoperatively to investigate VPs pharmacokinetics. Serum and wound concentrations were measured at multiple intervals over 24 hours after closure. RESULTS All serum concentrations were subtherapeutic (<15μg/mL) and peaked 12 hours after closure (4.7μg/mL; standard deviation [SD], 3.2). Wound concentrations were 922 μg/mL (SD, 523) 3 hours after closure and 207 μg/mL (SD, 317) at 24 hours. VP had a half-life of 7.2 hours (95% confidence interval, 7.0-9.3) in TJA wounds. CONCLUSIONS VP produced highly therapeutic intrawound concentrations while yielding low systemic levels in TJA. VP may serve as a safe adjunct in the prevention of periprosthetic joint infection.

Normalization of Left Ventricular Ejection Fraction and Incidence of Appropriate Antitachycardia Therapy in Patients With Implantable Cardioverter Defibrillator for Primary Prevention of Sudden Death

BACKGROUND Patients with severely depressed left ventricular ejection fractions (LVEFs) receive implantable cardioverter-defibrillators (ICDs) for the primary prevention of sudden death. In some patients, however, LVEF may improve or even normalize over time. Limited data are available on the incidence of appropriate antitachycardia therapy, including pacing and shock, in these patients. METHODS AND RESULTS We retrospectively identified consecutive patients at our institution with an ICD for primary prevention who had LVEF measurement available at initial implantation and at the time of generator replacement. None of these patients had ever received appropriate antitachycardia therapy before generator replacement. The incidence of appropriate antitachycardia therapy after generator replacement was assessed. Of the 125 patients who received generator replacement, 53 (42%) received an ICD and 72 (58%) a cardiac resynchronization therapy-defibrillator (CRT-D). Among them, 30 (21%) had LVEF normalized to ≥50%, 25 (17%) had LVEF partially improved to 36%-49%, and 70 (63%) had LVEF that remained depressed at ≤35%. During an overall follow-up period of 25 ± 18 months, none of the individuals with normalized LVEF experienced appropriate antitachycardia therapy regardless of ICD or CRT-D. Meanwhile, 20% of patients with LVEF at 36%-49% and 14% of patients with LVEF at ≤35% received appropriate ICD therapy. The omnibus P value for any differences among the 3 LVEF groups was 0.046 for the entire cohort, 0.01 for ICD, and 0.15 for CRT-D patients. CONCLUSIONS These preliminary data suggest that patients with reduced LVEF and primary-prevention ICDs who normalize their LVEF over time may be at lower risk of appropriate antitachycardia therapy.

Predicting neutropenia risk in patients with cancer using electronic data.

Objectives: Clinical guidelines recommending the use of myeloid growth factors are largely based on the prescribed chemotherapy regimen. The guidelines suggest that oncologists consider patient-specific characteristics when prescribing granulocyte-colony stimulating factor (G-CSF) prophylaxis; however, a mechanism to quantify individual patient risk is lacking. Readily available electronic health record (EHR) data can provide patient-specific information needed for individualized neutropenia risk estimation. An evidence-based, individualized neutropenia risk estimation algorithm has been developed. This study evaluated the automated extraction of EHR chemotherapy treatment data and externally validated the neutropenia risk prediction model. Materials and Methods: A retrospective cohort of adult patients with newly diagnosed breast, colorectal, lung, lymphoid, or ovarian cancer who received the first cycle of a cytotoxic chemotherapy regimen from 2008 to 2013 were recruited from a single cancer clinic. Electronically extracted EHR chemotherapy treatment data were validated by chart review. Neutropenia risk stratification was conducted and risk model performance was assessed using calibration and discrimination. Results: Chemotherapy treatment data electronically extracted from the EHR were verified by chart review. The neutropenia risk prediction tool classified 126 patients (57%) as being low risk for febrile neutropenia, 44 (20%) as intermediate risk, and 51 (23%) as high risk. The model was well calibrated (Hosmer-Lemeshow goodness-of-fit test = 0.24). Discrimination was adequate and slightly less than in the original internal validation (c-statistic 0.75 vs 0.81). Conclusion: Chemotherapy treatment data were electronically extracted from the EHR successfully. The individualized neutropenia risk prediction model performed well in our retrospective external cohort.

Effect of Pregnancy, Labor, Delivery and Postpartum on Physiological Pubic Symphysis Diastasis [23I]

INTRODUCTION: This study describes physiological pubic symphysis diastasis (PSD) and factors that affect PSD; whether the changes occur in pregnancy, labor or delivery; and whether postpartum regression occurs. METHODS: This prospective cohort enrolled 91 term nulliparous, English-speaking women, age >18 into three groups: 45 vaginal deliveries, 22 labored cesarean (CS) deliveries and 24 non-labored CS deliveries. PSD was assessed via pain scores and supine radiographs within 48 hours of delivery and after 6, 12 and 24 weeks. Maternal, fetal, labor and delivery variables were recorded. Analyses were performed using SAS 9.3. RESULTS: The overall mean PSD was 7.6 (SD 2.2). There was no difference in the mean PSD of women delivering vaginally (7.18 mm) versus CS (8.04 mm) (P=0.077). The mean PSD for labored and non-labored CS showed no difference. No intrapartum events impacted the degree of PSD. Pain scores correlated with degree of PSD (C=0.22) and regressed over time. Normalization (4–5 mm) of pregnancy PSD occurred by 6 weeks post partum. Physiological separation >10 mm was associated with increased pain scores postpartum and also occurred in patients undergoing elective cesarean. CONCLUSION: Physiological PSD occurs during pregnancy with minimal effects of labor and delivery as assessed immediately postpartum. Cesarean delivery does not prevent physiological PSD but protects against pathological PSD. The data supports physiological PSD as a hormone-related change. We hypothesize that elastic expansion and recoil of the pubic symphysis occurs with vaginal delivery.

OUTCOMES OF A DEMENTIA RESOURCE AND EDUCATION PROGRAM IMBEDDED IN A HEALTH CARE SYSTEM

P1-444 OUTCOMES OFA DEMENTIA RESOURCE AND EDUCATIONPROGRAMIMBEDDED INAHEALTH CARE SYSTEM Terry R. Barclay, Anna C. Forsberg, Avis J. Thomas, Jean M. Crow, Heidi Haley-Franklin, Leah R. Hanson, 1 HealthPartners Institute, Bloomington, MN, USA; 2 HealthPartners Center for Memory and Aging, St. Paul, MN, USA; Alzheimer’s Association Minnesota-North Dakota, Minneapolis, MN, USA. Contact e-mail: terry.r. barclay@healthpartners.com