1385. Pathway with single-dose long-acting intravenous antibiotic dalbavancin is a cost-saving alternative to usual inpatient care of acute bacterial skin and skin structure infections (ABSSSI)

Background

Acute bacterial skin and skin structure infections (ABSSSI) are a common type of bacterial infection, with the cost of hospitalization being the main contributing factor to overall treatment costs. Two pragmatic clinical trials (Table 1) demonstrated that a new treatment pathway in which patients are treated with the intravenous (IV) long-acting antibiotic, dalbavancin, reduced hospital admission rates and length of stay (LOS) in hospitalized patients. The objective of this study is to evaluate the cost-effectiveness of a single dose of dalbavancin administered in the emergency department (ED) compared with IV antibiotics for appropriate patients who would otherwise be admitted to hospital and receive usual care such as vancomycin or daptomycin. Table 1.

Effectiveness of mRNA Covid-19 Vaccine among U.S. Health Care Personnel

BACKGROUND

The prioritization of U.S. health care personnel for early receipt of messenger RNA (mRNA) vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 (Covid-19), allowed for the evaluation of the effectiveness of these new vaccines in a real-world setting.

METHODS

We conducted a test-negative case-control study involving health care personnel across 25 U.S. states. Cases were defined on the basis of a positive polymerase-chain-reaction (PCR) or antigen-based test for SARS-CoV-2 and at least one Covid-19-like symptom. Controls were defined on the basis of a negative PCR test for SARS-CoV-2, regardless of symptoms, and were matched to cases according to the week of the test date and site. Using conditional logistic regression with adjustment for age, race and ethnic group, underlying conditions, and exposures to persons with Covid-19, we estimated vaccine effectiveness for partial vaccination (assessed 14 days after receipt of the first dose through 6 days after receipt of the second dose) and complete vaccination (assessed ≥7 days after receipt of the second dose).

RESULTS

The study included 1482 case participants and 3449 control participants. Vaccine effectiveness for partial vaccination was 77.6% (95% confidence interval [CI], 70.9 to 82.7) with the BNT162b2 vaccine (Pfizer-BioNTech) and 88.9% (95% CI, 78.7 to 94.2) with the mRNA-1273 vaccine (Moderna); for complete vaccination, vaccine effectiveness was 88.8% (95% CI, 84.6 to 91.8) and 96.3% (95% CI, 91.3 to 98.4), respectively. Vaccine effectiveness was similar in subgroups defined according to age (<50 years or ≥50 years), race and ethnic group, presence of underlying conditions, and level of patient contact. Estimates of vaccine effectiveness were lower during weeks 9 through 14 than during weeks 3 through 8 after receipt of the second dose, but confidence intervals overlapped widely.

CONCLUSIONS

The BNT162b2 and mRNA-1273 vaccines were highly effective under real-world conditions in preventing symptomatic Covid-19 in health care personnel, including those at risk for severe Covid-19 and those in racial and ethnic groups that have been disproportionately affected by the pandemic. (Funded by the Centers for Disease Control and Prevention.).

New Designer Drugs

In recent years, there has been an emergence of numerous novel drugs. Such toxicity may occur in both adolescents and adults. This article discusses the opioid epidemic and several emerging opioids, including buprenorphine, loperamide, fentanyl, fentanyl derivatives, and others. Kratom, a plant occasionally used for opiate detoxification, along with the sedatives etizolam and phenibut, will be discussed. Lastly, this article discusses the phenethylamines and marijuana.

Identification of pathogens from the upper respiratory tract of adult emergency department patients at high risk for influenza complications in a pre-Sars-CoV-2 environment

The emergence of SARS-CoV-2 and subsequent COVID-19 pandemic highlights the morbidity and potential disease severity caused by respiratory viruses. To elucidate pathogen prevalence, etiology of coinfections and URIs from symptomatic adult Emergency department patients in a pre-SARS-CoV-2 environment, we evaluated specimens from four geographically diverse Emergency departments in the United States from 2013-2014 utilizing ePlex RP RUO cartridges (Genmark Diagnostics). The overall positivity was 30.1% (241/799), with 6.6% (16/241) coinfections. Noninfluenza pathogens from most to least common were rhinovirus/enterovirus, coronavirus, human metapneumovirus and RSV, respectively. Broad differences in disease prevalence and pathogen distributions were observed across geographic regions; the site with the highest detection rate (for both mono and coinfections) demonstrated the greatest pathogen diversity. A variety of respiratory pathogens and geographic variations in disease prevalence and copathogen type were observed. Further research is required to evaluate the clinical relevance of these findings, especially considering the SARS-CoV-2 pandemic and related questions regarding SARS-CoV-2 disease severity and the presence of co-infections.

Emergence of Extended-Spectrum β-Lactamase Urinary Tract Infections Among Hospitalized Emergency Department Patients in the United States

STUDY OBJECTIVE

Enterobacteriaceae resistant to ceftriaxone, mediated through extended-spectrum β-lactamases (ESBLs), commonly cause urinary tract infections worldwide, but have been less prevalent in North America. Current US rates are unknown. We determine Enterobacteriaceae antimicrobial resistance rates among US emergency department (ED) patients hospitalized for urinary tract infection.

METHODS

We prospectively enrolled adults hospitalized for urinary tract infection from 11 geographically diverse university-affiliated hospital EDs during 2018 to 2019. Among participants with culture-confirmed infection, we evaluated prevalence of antimicrobial resistance, including that caused by ESBL-producing Enterobacteriaceae, resistance risk factors, and time to in vitro-active antibiotics.

RESULTS

Of 527 total participants, 444 (84%) had cultures that grew Enterobacteriaceae; 89 of 435 participants (20.5%; 95% confidence interval 16.9% to 24.5%; 4.6% to 45.4% by site) whose isolates had confirmatory testing had bacteria that were ESBL producing. The overall prevalence of ESBL-producing Enterobacteriaceae infection among all participants with urinary tract infection was 17.2% (95% confidence interval 14.0% to 20.7%). ESBL-producing Enterobacteriaceae infection risk factors were hospital, long-term care, antibiotic exposure within 90 days, and a fluoroquinolone- or ceftriaxone-resistant isolate within 1 year. Enterobacteriaceae resistance rates for other antimicrobials were fluoroquinolone 32.3%, gentamicin 13.7%, amikacin 1.3%, and meropenem 0.3%. Ceftriaxone was the most common empirical antibiotic. In vitro-active antibiotics were not administered within 12 hours of presentation to 48 participants (53.9%) with ESBL-producing Enterobacteriaceae infection, including 17 (58.6%) with sepsis. Compared with other Enterobacteriaceae infections, ESBL infections were associated with longer time to in vitro-active treatment (17.3 versus 3.5 hours).

CONCLUSION

Among adults hospitalized for urinary tract infection in many US locations, ESBL-producing Enterobacteriaceae have emerged as a common cause of infection that is often not initially treated with an in vitro-active antibiotic.

Effect of Initial Bedside Ultrasonography on Emergency Department Skin and Soft Tissue Infection Management

STUDY OBJECTIVE

We examine the utility of emergency department (ED) ultrasonography in treatment of skin and soft tissue infections.

METHODS

We enrolled ED patients with skin and soft tissue infections and surveyed clinicians in regard to their pre-ultrasonography certainty about the presence or absence of an abscess, their planned management, post-ultrasonography findings, and actual management. We determined sensitivity and specificity of ultrasonography and clinical evaluation, and assessed appropriateness of management changes based on initial clinical assessment and outcomes through 1-week follow-up.

RESULTS

Among 1,216 patients, clinicians were uncertain of abscess presence in 105 cases (8.6%) and certain for 1,111 cases (91.4%). Based on surgical exploration and follow-up through 1 week, sensitivity and specificity for abscess detection by clinical evaluation were 90.3% and 97.7%, and by ultrasonography were 94.0% and 94.1%, respectively. Among 1,111 cases for which the clinician was certain, sensitivity and specificity of clinical evaluation were 96.6% and 97.3% compared with ultrasonographic evaluation sensitivity and specificity of 95.7% and 96.2%, respectively. Of 105 uncertain cases, sensitivity and specificity of ultrasonography were 68.5% and 80.4%. Ultrasonography changed management in 13 of 1,111 certain cases (1.2%), appropriately in 10 of 13 (76.9%) and inappropriately in 3 of 13 (23.1%). Of 105 uncertain cases, ultrasonography changed management in 25 (23.8%), appropriately in 21 of 25 (84.0%) and inappropriately in 4 of 25 (16.0%).

CONCLUSION

Ultrasonography rarely changed management when clinicians were certain about the presence or absence of an abscess. When they were uncertain, ultrasonography changed drainage decisions in approximately one quarter of cases, of which most (84%) were appropriate.

Highly Elevated Quantitative D-Dimer Assay Values Increase the Likelihood of Venous Thromboembolism

Objectives  In patients with suspected venous thromboembolism (VTE), the D-dimer assay is commonly utilized as part of the workup. The assay is primarily used to determine whether to proceed with radiographic imaging. We compared D-dimer levels in patients suspected of having VTE. We hypothesized that higher D-dimer values predict a higher likelihood of subsequent VTE diagnosis.

Methods  We conducted a secondary analysis of a multinational, prospective observational study of low- to intermediate-risk adult patients presenting to the emergency department with suspicion of VTE. Demographic and clinical data were collected in a structured manner. Advanced imaging including ultrasound, computed tomography (CT) pulmonary angiography, and ventilation/perfusion scanning was obtained at the discretion of the treating physicians. Imaging was evaluated by board-certified radiologists in real time. D-dimer values' bins were evaluated using a logistic regression model.

Results  We evaluated 1,752 patients for suspected deep vein thrombosis (DVT), with 191 (10.4%) DVT positive. We evaluated 1,834 patients for suspected pulmonary embolism (PE), with 108 (5.9%) PE positive. Higher D-dimer values in both groups were associated with higher likelihood of subsequent VTE diagnosis, with D-dimer values > 3,999 ng/mL in both groups having the highest incidence of VTE. More than 50% of those patients were VTE positive.

Conclusions  Increasing D-dimer values predict increased likelihood of being found VTE positive in this patient population. Among those in the highest D-dimer category, > 3,999 ng/mL, over half of patients were VTE positive. Further research could determine additional nuance in D-dimer as a tool to work up suspected VTE.

Subgroup Analysis of Antibiotic Treatment for Skin Abscesses

STUDY OBJECTIVE

Two large randomized trials recently demonstrated efficacy of methicillin-resistant Staphylococcus aureus (MRSA)-active antibiotics for drained skin abscesses. We determine whether outcome advantages observed in one trial exist across lesion sizes and among subgroups with and without guideline-recommended antibiotic indications.

METHODS

We conducted a planned subgroup analysis of a double-blind, randomized trial at 5 US emergency departments, demonstrating superiority of trimethoprim-sulfamethoxazole (320/1,600 mg twice daily for 7 days) compared with placebo for patients older than 12 years with a drained skin abscess. We determined between-group differences in rates of clinical (no new antibiotics) and composite cure (no new antibiotics or drainage) through 7 to 14 and 42 to 56 days after treatment among subgroups with and without abscess cavity or erythema diameter greater than or equal to 5 cm, history of MRSA, fever, diabetes, and comorbidities. We also evaluated treatment effect by lesion size and culture result.

RESULTS

Among 1,057 mostly adult participants, median abscess cavity and erythema diameters were 2.5 cm (range 0.1 to 16.0 cm) and 6.5 cm (range 1.0 to 38.5), respectively; 44.3% grew MRSA. Overall, for trimethoprim-sulfamethoxazole and placebo groups, clinical cure rate at 7 to 14 days was 92.9% and 85.7%; composite cure rate at 7 to 14 days was 86.5% and 74.3%, and at 42 to 56 days, it was 82.4% and 70.2%. For all outcomes, across lesion sizes and among subgroups with and without guideline antibiotic criteria, trimethoprim-sulfamethoxazole was associated with improved outcomes. Treatment effect was greatest with history of MRSA infection, fever, and positive MRSA culture.

CONCLUSION

Treatment with trimethoprim-sulfamethoxazole was associated with improved outcomes regardless of lesion size or guideline antibiotic criteria.

A Randomized Trial of Clindamycin Versus Trimethoprim-sulfamethoxazole for Uncomplicated Wound Infection

BACKGROUND

With the emergence of community-associated methicillin-resistant Staphylococcus aureus (MRSA) in the United States, visits for skin infections greatly increased. Staphylococci and streptococci are considered predominant causes of wound infections. Clindamycin and trimethoprim-sulfamethoxazole (TMP-SMX) are commonly prescribed, but the efficacy of TMP-SMX has been questioned.

METHODS

We conducted a randomized, double-blind, superiority trial at 5 US emergency departments. Patients >12 years of age with an uncomplicated wound infection received oral clindamycin 300 mg 4 times daily or TMP-SMX 320 mg/1600 mg twice daily, each for 7 days. We compared the primary outcome, wound infection cure at 7-14 days, and secondary outcomes through 6-8 weeks after treatment, in the per-protocol population.

RESULTS

Subjects had a median age of 40 years (range, 14-76 years); 40.1% of wound specimens grew MRSA, 25.7% methicillin-susceptible S. aureus, and 5.0% streptococci. The wound infection was cured at 7-14 days in 187 of 203 (92.1%) clindamycin-treated and 182 of 198 (91.9%) TMP-SMX-treated subjects (difference, 0.2%; 95% confidence interval [CI], -5.8% to 6.2%; P = not significant). The clindamycin group had a significantly lower rate of recurrence at 7-14 days (1.5% vs 6.6%; difference, -5.1%; 95% CI, -9.4% to -.8%) and through 6-8 weeks following treatment (2.0% vs 7.1%; difference, -5.1%; 95% CI, -9.7% to -.6%). Other secondary outcomes were statistically similar between groups but tended to favor clindamycin. Adverse event rates were similar.

CONCLUSIONS

In settings where MRSA is prevalent, clindamycin and TMP-SMX produce similar cure and adverse event rates among patients with an uncomplicated wound infection. Further study evaluating differential effects of antibiotics on recurrent infection may be warranted.

CLINICAL TRIALS REGISTRATION

NCT00729937.

Trimethoprim-Sulfamethoxazole versus Placebo for Uncomplicated Skin Abscess

BACKGROUND

U.S. emergency department visits for cutaneous abscess have increased with the emergence of methicillin-resistant Staphylococcus aureus (MRSA). The role of antibiotics for patients with a drained abscess is unclear.

METHODS

We conducted a randomized trial at five U.S. emergency departments to determine whether trimethoprim-sulfamethoxazole (at doses of 320 mg and 1600 mg, respectively, twice daily, for 7 days) would be superior to placebo in outpatients older than 12 years of age who had an uncomplicated abscess that was being treated with drainage. The primary outcome was clinical cure of the abscess, assessed 7 to 14 days after the end of the treatment period.

RESULTS

The median age of the participants was 35 years (range, 14 to 73); 45.3% of the participants had wound cultures that were positive for MRSA. In the modified intention-to-treat population, clinical cure of the abscess occurred in 507 of 630 participants (80.5%) in the trimethoprim-sulfamethoxazole group versus 454 of 617 participants (73.6%) in the placebo group (difference, 6.9 percentage points; 95% confidence interval [CI], 2.1 to 11.7; P=0.005). In the per-protocol population, clinical cure occurred in 487 of 524 participants (92.9%) in the trimethoprim-sulfamethoxazole group versus 457 of 533 participants (85.7%) in the placebo group (difference, 7.2 percentage points; 95% CI, 3.2 to 11.2; P<0.001). Trimethoprim-sulfamethoxazole was superior to placebo with respect to most secondary outcomes in the per-protocol population, resulting in lower rates of subsequent surgical drainage procedures (3.4% vs. 8.6%; difference, -5.2 percentage points; 95% CI, -8.2 to -2.2), skin infections at new sites (3.1% vs. 10.3%; difference, -7.2 percentage points; 95% CI, -10.4 to -4.1), and infections in household members (1.7% vs. 4.1%; difference, -2.4 percentage points; 95% CI, -4.6 to -0.2) 7 to 14 days after the treatment period. Trimethoprim-sulfamethoxazole was associated with slightly more gastrointestinal side effects (mostly mild) than placebo. At 7 to 14 days after the treatment period, invasive infections had developed in 2 of 524 participants (0.4%) in the trimethoprim-sulfamethoxazole group and in 2 of 533 participants (0.4%) in the placebo group; at 42 to 56 days after the treatment period, an invasive infection had developed in 1 participant (0.2%) in the trimethoprim-sulfamethoxazole group.

CONCLUSIONS

In settings in which MRSA was prevalent, trimethoprim-sulfamethoxazole treatment resulted in a higher cure rate among patients with a drained cutaneous abscess than placebo. (Funded by the National Institute of Allergy and Infectious Diseases; ClinicalTrials.gov number, NCT00729937.).

Identification of acute HIV infection using fourth-generation testing in an opt-out emergency department screening program

STUDY OBJECTIVE

Acute HIV infection is a clinical diagnosis aided by technology. Detecting the highly infectious acute stage of HIV infection is critical to reducing transmission and improving long-term outcomes. The Maricopa Integrated Health System implemented nontargeted, opt-out HIV screening with a fourth-generation antigen/antibody combination HIV assay test in our adult emergency department (ED) at Maricopa Medical Center to assess the prevalence of both acute and chronic unrecognized HIV.

METHODS

Eligible patients aged 18 to 64 years were tested for HIV if they did not opt out and had blood drawn as part of their ED care. Patients were not eligible if they had a known HIV or AIDS diagnosis, exhibited altered mental status, were a current resident of a long-term psychiatric or correctional facility, or prompted a trauma activation. Reactive test results were delivered by a physician with the assistance of a linkage-to-care specialist. Specimens with a reactive fourth-generation assay result underwent confirmatory testing.

RESULTS

From July 11, 2011, through January 5, 2014, 27,952 HIV screenings were performed for 22,468 patients tested for HIV; 78 (0.28%) had new HIV diagnoses. Of those, 18 (23% of all new diagnoses) were acute HIV infections, and 22 patients (28%) had a CD4 count of less than 200 cells/mL, or an opportunistic infection.

CONCLUSION

HIV testing with a fourth-generation antigen/antibody laboratory test producing rapid results is feasible in an ED. Unexpectedly, nearly one fourth of patients with undiagnosed HIV had acute infections, which would have been more difficult to detect with previous testing technology.

Heparin-induced thrombocytopenia

Abstract A summary of heparin-induced thrombocytopenia (HIT) is presented. HIT is an adverse drug reaction characterized by thrombocytopenia and a high risk for venous or arterial thrombosis. The frequency of HIT ranges from 1 to 5% of patients receiving heparin with exact frequencies ranging between specific agents. Interestingly, this immune-mediated syndrome is ironically associated with thrombosis, not bleeding, with thrombin formation playing a major role. It is caused by heparin-dependent, platelet-activating antibodies that identifies a self-protein, PF4, bound to heparin that results in an antibody formation. The resulting platelet activation is associated with increased thrombin generation. Typically, the platelet count fall begins 5-10 days after starting heparin, although a rapid platelet count fall can occur in a patient who has antibodies from recent heparin use. Typical causes of HIT as well as the best diagnostic studies and treatment are discussed in this review. HIT was reviewed using a pubmed™ search; google scholar™ using key words: "Heparin-induced thrombocytopenia"; "heparin", and "drug AND thrombocytopenia."

Plasma and urine dimercaptopropanesulfonate concentrations after dermal application of transdermal DMPS (TD-DMPS)

2,3-Dimercaptopropane-1-sulfonate (DMPS) is a metal chelator approved in Europe for oral or intravenous use for heavy metal poisoning. Transdermally applied DMPS (TD-DMPS) is used by some alternative practitioners to treat autism, despite the absence of evidence for its efficacy. We found no literature evaluating the pharmacokinetics of the transdermal route of delivery or the ability of TD-DMPS to enhance urinary mercury elimination. We hypothesized that TD-DMPS is not absorbed. Eight adult volunteers underwent application of 1.5-3 drops/kg of TD-DMPS. Subjects provided 12-h urine collections the day before and day of application. Subjects underwent blood draws at 0, 30, 60,90, 120, and 240 min after TD-DMPS application. Plasma and urine were assayed for the presence of DMPS. Urine was assayed for any change in urinary mercury excretion after DMPS. One control subject ingested 250 mg of oral DMPS and underwent the same urine and blood collections and analyses. No subject had detectable urine DMPS or increased urine mercury excretion after TD-DMPS. One subject had detectable levels of DMPS in the 30-min plasma sample, suspected to be contamination. All other samples for that subject and the other seven subjects showed no detectable plasma DMPS. The control subject had detectable urine and plasma DMPS levels and increased urine mercury excretion. These results indicate that TD-DMPS is not absorbed. There was no increase in urine mercury excretion after TD-DMPS. Our results argue that TD-DMPS is an ineffective metal chelator.

Diagnostic characteristics of S100A8/A9 in a multicenter study of patients with acute right lower quadrant abdominal pain

OBJECTIVES

Over the past decade, clinicians have become increasingly reliant on computed tomography (CT) for the evaluation of patients with suspected acute appendicitis. To limit the radiation risks and costs of CT, investigators have searched for biomarkers to aid in diagnostic decision-making. We evaluated one such biomarker, calprotectin or S100A8/A9, and determined the diagnostic performance characteristics of a developmental biomarker assay in a multicenter investigation of patients presenting with acute right lower quadrant abdominal pain.

METHODS

This was a prospective, double-blinded, single-arm, multicenter investigation performed in 13 emergency departments (EDs) from August 2009 to April 2010 of patients presenting with acute right lower quadrant abdominal pain. Plasma samples were tested using the investigational S100A8/A9 assay. The primary outcome of acute appendicitis was determined by histopathology for patients undergoing appendectomy or 2-week telephone follow-up for patients discharged without surgery. The sensitivity, specificity, negative likelihood ratio (LR-), and positive likelihood ratio (LR+) of the biomarker assay were calculated using the prespecified cutoff value of 14 units. A post hoc stability study was performed to investigate the potential effect of time and courier transport on the measured value of the S100A8/A9 assay test results.

RESULTS

Of 1,052 enrolled patients, 848 met criteria for analysis. The median age was 24.5 years (interquartile range [IQR] = 16-38 years), 57% were female, and 50% were white. There was a 27.5% prevalence of acute appendicitis. The sensitivity and specificity for the investigational S100A8/A9 assay in diagnosing acute appendicitis were estimated to be 96% (95% confidence interval [CI] = 93% to 98%) and 16% (95% CI = 13% to 19%), respectively. The LR- ratio was 0.24 (95% CI = 0.12 to 0.47), and the LR+ was 1.14 (95% CI = 1.10 to 1.19). The post hoc stability study demonstrated that in the samples that were shipped, the estimated time coefficient was 7.6 × 10(-3) ± 2.0 × 10(-3) log units/hour, representing an average increase of 43% in the measured value over 48 hours; in the samples that were not shipped, the estimated time coefficient was 2.5 × 10(-3) ± 0.4 × 10(-3) log units/hour, representing a 13% increase on average in the measured value over 48 hours, which was the maximum delay allowed by the study protocol. Thus, adjusting the cutoff value of 14 units by the magnitude of systematic inflation observed in the stability study at 48 hours would result in a new cutoff value of 20 units and a "corrected" sensitivity and specificity of 91 and 28%, respectively.

CONCLUSIONS

In patients presenting with acute right lower quadrant abdominal pain, we found the investigational enzyme-linked immunosorbent assay (ELISA) test for S100A8/A9 to perform with high sensitivity but very limited specificity. We found that shipping effect and delay in analysis resulted in a subsequent rise in test values, thereby increasing the sensitivity and decreasing the specificity of the test. Further investigation with hospital-based laboratory analyzers is the next critical step for determining the ultimate clinical utility of the ELISA test for S100A8/A9 in ED patients presenting with acute right lower quadrant abdominal pain.

Bee swarmings in children

Africanized honeybees (Apis mellifera scutellata) are now found in the southern and southwestern United States. Swarmings can result in hundreds to thousands of stings delivering a venom load capable of producing multisystem organ failure and death. The literature on mass envenomations is scarce, being limited to case reports and case series. There are no prospective studies on mass envenomations in children.

METHODS

All patients were admitted to our toxicology service, and all stingers were counted. Laboratory data and clinical assessments were obtained at baseline, 8, and 16 hours after presentation.

RESULTS

Nineteen patients with a median age of 3.6 years and a median of 2.64 stings per kilogram (range, 1-4.5) were enrolled. Fifteen children had vomiting. Only a mild increase in creatine kinase was seen. None developed coagulopathy or renal insufficiency.

CONCLUSION

Envenomations of up to 4.5 stings per kilogram resulted in only mild systemic illness. Vomiting does not portend involvement of other organ systems.

Isolated atomoxetine (Strattera™) ingestions commonly result in toxicity

Atomoxetine is a recently approved medication for attention deficit disorder. It is a selective norepinephrine reuptake inhibitor with an onset of action within 2 h, and a duration of effect up to 40 h in therapeutic doses. Experience in the overdose setting is limited. After brief training in systematic chart review, reviewers blinded to the purpose of the study completed a standardized data collection sheet. Two years after atomoxetine was released, poison center patient encounters were reviewed. Age, outcomes, and signs and symptoms were recorded. All patients were followed until the cessation of symptoms or 24 h. Seventeen cases of isolated atomoxetine were reviewed. The age range of these 6 patients was 9 months to 28 years old with a mean of 15.6 years. The range of amount ingested was 10-1200 mg. The onset of symptoms was delayed as long as 3 h in 3 patients. All neurological symptoms were preceded by tachycardia. Ten of 17 patients had tachycardia, 6/17 had emesis, and 3/17 had agitation that required benzodiazepines to control. All symptoms resolved within 30 h. Supratherapeutic ingestions of atomoxetine can result in transient tachycardia, vomiting, and cognitive disturbances.

Do Rh-negative women with first trimester spontaneous abortions need Rh immune globulin?

OBJECTIVE

To examine whether literature supports the use of Rh immune globulin in Rh-negative women with first trimester spontaneous abortions to prevent maternal sensitization to the fetal Rh antigen and subsequent fetal morbidity and mortality.

METHODS

We searched MEDLINE (1966-2005), the Cochrane Central Register of Controlled Trials, EMBASE (1990 to 2005), and the reference sections of the articles found. The search is considered updated to December of 2005. Search terms included vaginal bleeding, Rh negative, Rh immune globulin, RhoGAM, isoimmunization, sensitization, first trimester pregnancy, threatened, and spontaneous abortion.

RESULTS

The evidence to support the use of Rh immune globulin for a diagnosis of first trimester spontaneous abortion is minimal. There is a paucity of well-designed research that examines maternal sensitization or hemolytic disease of the newborn as an outcome in patients receiving, versus not receiving, Rh immune globulin in first trimester bleeding. There is significant evidence to demonstrate fetomaternal hemorrhage in first trimester spontaneous abortions; yet, no studies demonstrate subsequent maternal sensitization or development hemolytic disease in the fetus as a result of this hemorrhage.

CONCLUSION

In summary, there is minimal evidence that administering Rh immune globulin for first trimester vaginal bleeding prevents maternal sensitization or development of hemolytic disease of the newborn. The practice of administering Rh immune globulin to Rh-negative women with a first trimester spontaneous abortion is based on expert opinion and extrapolation from experience with fetomaternal hemorrhage in late pregnancy. Its use for first trimester bleeding is not evidence-based.

Initial postmarketing experience with crotalidae polyvalent immune Fab for treatment of rattlesnake envenomation

STUDY OBJECTIVE

We describe our postmarketing experience with patients receiving Crotalidae polyvalent immune Fab (CroFab; FabAV) antivenom for treatment of rattlesnake envenomation.

METHODS

The charts of 28 patients admitted between March 1 and September 9, 2001, with rattlesnake envenomation and treated with FabAV were reviewed for demographic information, time until antivenom treatment, laboratory findings, evidence of hypersensitivity reaction, length of hospital stay, and readmission to the hospital.

RESULTS

All patients had swelling, 20 patients had elevated prothrombin times (>14 seconds), 12 patients had low fibrinogen levels (<170 mg/dL), and 6 patients had thrombocytopenia (platelet count <120,000/mm(3)) on presentation. The total dose of FabAV ranged from 10 to 47 vials per patient. Hypofibrinogenemia was resistant to FabAV in some patients. On follow-up, recurrence of coagulopathy was detected in 3 patients, and recurrence of thrombocytopenia was detected in 1 patient. Two patients demonstrated delayed-onset severe thrombocytopenia. Recurrence or delayed-onset toxicity might have been underestimated because of incomplete follow-up in some patients. No acute hypersensitivity reactions occurred. Two patients reported mild symptoms of possible serum sickness on follow-up.

CONCLUSION

FabAV effectively controlled the effects of envenomation; however, initial control of coagulopathy was difficult to achieve in some cases, and recurrence or delayed-onset hematotoxicity was common. When initially managing hematotoxicity, a trend toward normalization of laboratory values might be a more reasonable end point for FabAV treatment than attainment of normal reference values in nonbleeding patients.

Intravenous pyridoxine-induced metabolic acidosis

STUDY OBJECTIVE

Pyridoxine hydrochloride, the antidote for isonicotinic acid hydrazide (INH)--induced seizures, is available in solution at a concentration of 100 mg/mL at a pH of less than 3. Pyridoxine is often infused rapidly in large doses for INH-induced seizures. Effects of pyridoxine infusion on base deficit in amounts given for INH poisoning have not been studied in human subjects. We hypothesized that this infusion would result in transient worsening of acidosis.

METHODS

We conducted a randomized, controlled crossover trial in human volunteers. Five healthy volunteers (mean age, 35 years; range, 29 to 43 years) were randomized to receive intravenous placebo (50 mL of normal saline solution) or 5 g of pyridoxine (50 mL) over 5 minutes. A peripheral intravenous catheter was established in each arm, and a heparinized venous blood sample was obtained for base deficit at baseline and 3, 6, 10, 20, and 30 minutes after infusion. After at least a 1-week washout period, the volunteers were assigned to the alternate arms of the experiments, thus acting as their own control subjects. Data were analyzed by using the 2-tailed paired t test, controlling for multiple comparisons.

RESULTS

No difference was noted between groups at baseline. A statistically significant increased base deficit was noted after the pyridoxine infusion versus control at 3 to 20 minutes but not at 30 minutes (P =.1). Maximal mean increase in base deficit (2.74 mEq/L) was noted at 3 minutes.

CONCLUSION

A transient increase in base deficit occurs after the infusion of 5 g of pyridoxine in normal volunteers.