y+ cationic amino acid transport of arginine in packed red blood cells.

BACKGROUND: Transfusion of packed red blood cells (PRBCs) is associated with morbidity and mortality. The mechanisms are not fully understood. Packed red blood cells deplete extracellular arginine and possess transporters for arginine, an amino acid essential for normal immunity. We hypothesize that the membrane y+ amino acid transporter contributes to arginine depletion in PRBCs. MATERIALS AND METHODS: We titrated PRBCs to a 10% hematocrit with phosphate-buffered saline, blocked PRBC y+ transporters using n-ethylmaleimide (0.2 mM), and measured arginine and ornithine levels using liquid chromatography-mass spectroscopy. We added radiolabeled L-arginine [4,5-(3)H] (10 µmol/L) added to similar culture conditions and measured arginine uptake in counts per minute (CPM). We examined storage periods of 6-9 d, 1-4 wk, and 6 wk, and correlated donor demographics with arginine uptake. RESULTS: n-Ethylmaleimide blockade of y+ transporters impaired PRBC arginine depletion from culture media (117.6 ± 8.6 µM versus 76.9 ± 5.8 µM; P < 0.001) and reduced intracellular L-arginine (7,574 ± 955 CPM versus 18,192 ± 1,376 CPM; P < 0.01). Arginine depletion increased with storage duration (1 wk versus 6 wk; P < 0.002). With n-ethylmaleimide treatment, 6-wk-old PRBCs preserved more culture arginine (P < 0.008) than at shorter durations. Nine-day storage duration increased L-arginine uptake compared with 6- to 8-day storage (n = 77, R = 0.225, P < 0.05). Extracellular arginine depletion and extracellular ornithine synthesis varied among donors and correlated inversely (R = -0.5, P = 0.01). CONCLUSIONS: Membrane y+ transporters are responsible for arginine depletion by PRBCs. Membrane y+ activity increases with storage duration. Arginine uptake varies among donors. Membrane biology of RBCs may have a role in the negative clinical effects associated with PRBC transfusion.

Asystole Following Concomitant Intravenous Administration of Neostigmine and Dexmedetomidine in a Patient With Acute Colonic Pseudo-Obstruction.

Acute colonic pseudo-obstruction (ACPO) is a condition characterized by acute dilation of the large bowel without evidence of mechanical obstruction that occurs in a variety of hospitalized patients with many predisposing factors. Management includes supportive care and limitation of offending medications with mainstays of treatment of neostigmine administration and colonic decompression. We report the case of a critically ill patient with ACPO who experienced bradycardia and a brief episode of asystole when receiving concomitant dexmedetomidine and neostigmine infusions but who later remained hemodynamically stable when receiving propofol and neostigmine infusions. The bradycardia and associated hemodynamic instability experienced while on dexmedetomidine and neostigmine infusions were rapidly corrected with atropine and cessation of offending agents. Because ACPO is encountered frequently and the use of dexmedetomidine as a sedative agent in the ICU is increasing, practitioners should be aware of the additive risk of bradycardia and potential for asystole with the combination of neostigmine and dexmedetomidine. Electronic drug interaction databases should be updated and drug information sources should include a drug-drug interaction between dexmedetomidine and neostigmine to reduce the likelihood of concomitant administration.

An acute care surgery rotation contributes significant general surgical operative volume to residency training compared with other rotations.

BACKGROUND: Surgical resident rotations on trauma services are criticized for little operative experience and heavy workloads. This has resulted in diminished interest in trauma surgery among surgical residents. Acute care surgery (ACS) combines trauma and emergency/elective general surgery, enhancing operative volume and balancing operative and nonoperative effort. We hypothesize that a mature ACS service provides significant operative experience. METHODS: A retrospective review was performed of ACGME case logs of 14 graduates from a major, academic, Level I trauma center program during a 3-year period. Residency Review Committee index case volumes during the fourth and fifth years of postgraduate training (PGY-4 and PGY-5) ACS rotations were compared with other service rotations: in total and per resident week on service. RESULTS: Ten thousand six hundred fifty-four cases were analyzed for 14 graduates. Mean cases per resident was 432 ± 57 in PGY-4, 330 ± 40 in PGY-5, and 761 ± 67 for both years combined. Mean case volume on ACS for both years was 273 ± 44, which represented 35.8% (273 of 761) of the total experience and exceeded all other services. Residents averaged 8.9 cases per week on the ACS service, which exceeded all other services except private general surgery, gastrointestinal/minimally invasive surgery, and pediatric surgery rotations. Disproportionately more head/neck, small and large intestine, gastric, spleen, laparotomy, and hernia cases occurred on ACS than on other services. CONCLUSIONS: Residents gain a large operative experience on ACS. An ACS model is viable in training, provides valuable operative experience, and should not be considered a drain on resident effort. Valuable ACS rotation experiences as a resident may encourage graduates to pursue ACS as a career.

Detecting direct oral anticoagulants in trauma patients using liquid chromatography-mass spectrometry: A novel approach to medication reconciliation.

BACKGROUND: Accurate medication reconciliation in trauma patients is essential but difficult. Currently, there is no established clinical method of detecting direct oral anticoagulants (DOACs) in trauma patients. We hypothesized that a liquid chromatography-mass spectrometry (LCMS)-based assay can be used to accurately detect DOACs in trauma patients upon hospital arrival. METHODS: Plasma samples were collected from 356 patients who provided informed consent including 10 healthy controls, 19 known positive or negative controls, and 327 trauma patients older than 65 years who were evaluated at our large, urban level 1 trauma center. The assay methodology was developed in healthy and known controls to detect apixaban, rivaroxaban, and dabigatran using LCMS and then applied to 327 samples from trauma patients. Standard medication reconciliation processes in the electronic medical record documenting DOAC usage were compared with LCMS results to determine overall accuracy, sensitivity, specificity, and positive and negative predictive values (PPV, NPV) of the assay. RESULTS: Of 356 patients, 39 (10.96%) were on DOACs: 21 were on apixaban, 14 on rivaroxaban, and 4 on dabigatran. The overall accuracy of the assay for detecting any DOAC was 98.60%, with a sensitivity of 94.87% and specificity of 99.05% (PPV, 92.50%; NPV, 99.37%). The assay detected apixaban with a sensitivity of 90.48% and specificity of 99.10% (PPV, 86.36%; NPV 99.40%). There were three false-positive results and two false-negative LCMS results for apixaban. Dabigatran and rivaroxaban were detected with 100% sensitivity and specificity. CONCLUSION: This LCMS-based assay was highly accurate in detecting DOACs in trauma patients. Further studies need to confirm the clinical efficacy of this LCMS assay and its value for medication reconciliation in trauma patients. LEVEL OF EVIDENCE: Diagnostic Test, level III.

Medications and patient safety in the trauma setting: a systematic review.

Background: Medication errors account for the most common adverse events and a significant cause of mortality in the USA. The Joint Commission has required medication reconciliation since 2006. We aimed to survey the literature and determine the challenges and effectiveness of medication reconciliation in the trauma patient population. Materials and methods: We conducted a systematic review of the literature to determine the effectiveness of medication reconciliation in trauma patients. English language articles were retrieved from PubMed/Medline, CINAHL, and Cochrane Review databases with search terms "trauma OR injury, AND medication reconciliation OR med rec OR med rek, AND effectiveness OR errors OR intervention OR improvements." Results: The search resulted in 82 articles. After screening for relevance and duplicates, the 43 remaining were further reviewed, and only four articles, which presented results on medication reconciliation in 3041 trauma patients, were included. Two were retrospective and two were prospective. Two showed only 4% accuracy at time of admission with 48% of medication reconciliations having at least one medication discrepancy. There were major differences across the studies prohibiting comparative statistical analysis. Conclusions: Trauma medication reconciliation is important because of the potential for adverse outcomes given the emergent nature of the illness. The few articles published at this time on medication reconciliation in trauma suggest poor accuracy. Numerous strategies have been implemented in general medicine to improve its accuracy, but these have not yet been studied in trauma. This topic is an important but unrecognized area of research in this field.

Redefining "bowel regimen": Pharmacologic strategies and nutritional considerations in the management of small bowel fistulas.

Enterocutaneous fistulae (ECF) and enteroatmospheric fistulae (EAF) are difficult complications that primarily arise after abdominal surgical procedures. Development of an ECF or EAF carries significant mortality and morbidity. Effective management of patients with these disease states requires a multidisciplinary approach, which includes surgical, pharmacotherapeutic, and nutritional interventions. This review focuses on the medical and nutritional management of ECF/EAF, providing background on drug agents and nutritional strategies that may be helpful in reducing effluent volume, optimizing fistula healing, and maintaining nutritional health.

Minimizing opioid use after acute major trauma.

PURPOSE: Results of an initiative at an academic medical center to reduce prescription opioid use in patients with acute traumatic injuries are reported. METHODS: In 2014, the University of Kentucky Hospital trauma service implemented a pain management strategy consisting of patient and provider education emphasizing the use of nonopioid analgesics to minimize opioid use without compromising analgesia effectiveness. To assess the impact of the initiative, a retrospective analysis of data on cohorts of patients admitted with acute trauma before (n = 489) and after (n = 424) project implementation was conducted. The primary endpoint was opioid use (prescribed daily milligram morphine equivalents [MME]) at discharge. Secondary endpoints included inpatient opioid and alternative analgesic use, pain control, ileus development, length of stay, and discharge disposition. RESULTS: Compared with the preintervention cohort, the postintervention cohort had a lower median daily discharge MME overall (45 MME versus 90 MME, p < 0.001); after stratification of MME data by baseline opioid use, this finding held true only for patients with no opioid prescription at admission. Although utilization of gabapentinoids, skeletal muscle relaxants, and clonidine increased during the postintervention period, inpatient opioid use did not differ significantly in the 2 cohorts. Utilization of both nonsteroidal antiinflammatory drugs and acetaminophen was lower in the postintervention cohort versus the preintervention cohort. CONCLUSION: Targeted provider and patient education on minimizing opioid use was associated with a reduction in MME on discharge from the hospital after traumatic injury.

General surgical operative duration is associated with increased risk-adjusted infectious complication rates and length of hospital stay.

BACKGROUND: Studies of specific procedures have shown increases in infectious complications with operative duration. We hypothesized that operative duration is independently associated with increased risk-adjusted infectious complication (IC) rates in a broad range of general surgical procedures. STUDY DESIGN: We queried the American College of Surgeons National Surgical Quality Improvement Program database for general surgical operations performed from 2005 to 2007. ICs (wound infection, sepsis, urinary tract infection, and/or pneumonia) and length of hospital stay (LOS) were evaluated versus operative duration (OD, ie, incision to closure). Multivariable regression adjusted for 38 patient risk variables, operation type and complexity, wound class and intraoperative transfusion. We also analyzed isolated laparoscopic cholecystectomies in patients of American Society of Anesthesiologists class 1 or 2, without intraoperative transfusion and with a clean or clean-contaminated wound class. RESULTS: In 299,359 operations performed at 173 hospitals, unadjusted IC rates increased linearly with OD at a rate of close to 2.5% per half hour (chi-square test for linear trend, p < 0.001). After adjustment, IC risk increased for each half hour of OD relative to cases lasting