Browsing by Author "Beam, Daren M."

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    Comparison of isoflurane and α-chloralose in an anesthetized swine model of acute pulmonary embolism producing right ventricular dysfunction
    (American Association for Laboratory Animal Science, 2015-02) Beam, Daren M.; Neto-Neves, Evandro M.; Stubblefield, William B.; Alves, Nathan J.; Tune, Johnathan D.; Kline, Jeffrey A.; Department of Emergency Medicine, IU School of Medicine
    Pulmonary embolism (PE) is a leading cause of sudden cardiac death, and a model is needed for testing potential treatments. In developing a model, we compared the hemodynamic effects of isoflurane and α-chloralose in an acute swine model of PE because the choice of anesthesia will likely affect the cardiovascular responses of an animal to PE. At baseline, swine that received α-chloralose (n = 6) had a lower heart rate and cardiac output and higher SpO2, end-tidal CO2, and mean arterial pressure than did those given isoflurane (n = 9). After PE induction, swine given α-chloralose compared with isoflurane exhibited a lower heart rate (63 ± 10 compared with 116 ± 15 bpm) and peripheral arterial pressure (52 ± 12 compared with 61 ± 12 mm Hg); higher SpO2 (98% ± 3% compared with 95% ± 1%), end-tidal CO2 (35 ± 4 compared with 32 ± 5), and systolic blood pressure (121 ± 8 compared with 104 ± 20 mm Hg); and equivalent right ventricular:left ventricular ratios (1.32 ± 0.50 compared with 1.23 ± 0.19) and troponin I mean values (0.09 ± 0.07 ng/mL compared with 0.09 ± 0.06 ng/mL). Isoflurane was associated with widely variable fibrinogen and activated partial thromboplastin time. Intraexperiment mortality was 0 of 6 animals for α-chloralose and 2 of 9 swine for isoflurane. All swine anesthetized with α-chloralose survived with sustained pulmonary hypertension, RV-dilation-associated cardiac injury without the confounding vasodilatory or coagulatory effects of isoflurane. These data demonstrate the physiologic advantages of α-chloralose over isoflurane for anesthesia in a swine model of severe submassive PE.
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    Effect of metabolic syndrome on mean pulmonary arterial pressures in patients with acute pulmonary embolism treated with catheter-directed thrombolysis
    (Elsevier, 2020-03-01) Stewart, Lauren K.; Beam, Daren M.; Casciani, Thomas; Cameron, Scott J.; Kline, Jeffrey A.; Emergency Medicine, School of Medicine
    Background: Metabolic syndrome (MetS) has been associated with a procoagulant and hypofibrinolytic state. Current data exploring the role of MetS in venous thromboembolism (VTE) are limited. The objective was to measure the prevalence of MetS in patients with acute PE receiving catheter-directed thrombolysis (CDT) and to investigate its effect on mean pulmonary arterial pressure and overall treatment success. Methods: We used a 3-year prospective registry of ED patients with acute PE with severity qualifying for activation of a PE response team (PERT). All patients had CDT with catheter-measured mPAP and angiography. The presence or absence of MetS components were extracted from chart review based on the following criteria: 1. body mass index (BMI) >30 kg/m2; 2. diagnosed hypertension; 3. diabetes mellitus (including HbA1c >6.5%) and; 4. dyslipidemia (including triglycerides >150 mg/dL or high-density lipoprotein <40 mg/dL). Results: Of the 134 patients, 85% met the criteria for at least one of four MetS components, with obesity being most common, present in 71%. Results demonstrated a positive concordance between the number of criteria for MetS and MPAP, both pre- and post-fibrinolysis, as pressures tended to increase with each additional MetS criterion. Multivariate regression analysis determined age (-), BMI (+) and hypertension (+) to be significant independent predictor variables for mPAP. Conclusions: MetS was common in patients with more severe manifestations of PE and was associated with higher mPAP values both at diagnosis and following treatment with CDT.
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    Implementation and preliminary clinical outcomes of a pharmacist-managed venous thromboembolism clinic for patients treated with rivaroxaban post emergency department discharge
    (Wiley, 2017) DiRenzo, Baely M.; Beam, Daren M.; Kline, Jeffrey A.; Deodhar, Karishma S.; Davis, Christina M.; Weber, Zachary A.; Walroth, Todd A.; Emergency Medicine, School of Medicine
    Objective To describe the implementation, work flow, and differences in outcomes between a pharmacist-managed clinic for the outpatient treatment of venous thromboembolism (VTE) using rivaroxaban versus care by a primary care provider. Interventions Patients in the studied health system that are diagnosed with low-risk VTE in the emergency department are often discharged without hospital admission. These patients are treated with rivaroxban and follow up either in a pharmacist-managed VTE clinic or with their primary care provider. Pharmacists in the VTE clinic work independently under a collaborative practice agreement. An evaluation of thirty-four patients, seventeen in each treatment arm, was conducted to compare the differences in treatment-related outcomes of rivaroxaban when managed by a pharmacist versus a primary care provider. Results The primary endpoint was a six month composite of anticoagulation treatment-related complications that included a diagnosis of major bleeding, recurrent thromboembolism, or fatality due to either major bleeding or recurrent thromboembolism. Secondary endpoints included number of hospitalizations, adverse events, and medication adherence. There was no difference in the primary endpoint between groups with one occurrence of the composite endpoint in each treatment arm (p=1.000), both of which were recurrent thromboembolic events. Medication adherence assessment was formally performed in 8 patients in the pharmacist group versus 0 patients in the control group. No differences were seen amongst other secondary endpoints. Conclusions The pharmacist-managed clinic is a novel expansion of clinical pharmacy services that treats patients with low-risk VTEs with rivaroxaban in the outpatient setting. The evaluation of outcomes provides support that pharmacist-managed care utilizing standardized protocols under a collaborative practice agreement may be as safe as care by a primary care provider.
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    Independent evaluation of a simple clinical prediction rule to identify right ventricular dysfunction in patients with shortness of breath
    (WB Saunders, 2015-04) Russell, Frances M.; Moore, Christopher L.; Courtney, D. Mark; Kabrhel, Christopher; Smithline, Howard A.; Nordenholz, Kristen E.; Richman, Peter B.; O’Neil, Brian J.; Plewa, Michael C.; Beam, Daren M.; Mastouri, Ronald; Kline, Jeffrey A.; Emergency Medicine, School of Medicine
    BACKGROUND: Many patients have unexplained persistent dyspnea after negative computed tomographic pulmonary angiography (CTPA). We hypothesized that many of these patients have isolated right ventricular (RV) dysfunction from treatable causes. We previously derived a clinical decision rule (CDR) for predicting RV dysfunction consisting of persistent dyspnea and normal CTPA, finding that 53% of CDR-positive patients had isolated RV dysfunction. Our goal is to validate this previously derived CDR by measuring the prevalence of RV dysfunction and outcomes in dyspneic emergency department patients. METHODS: A secondary analysis of a prospective observational multicenter study that enrolled patients presenting with suspected PE was performed. We included patients with persistent dyspnea, a nonsignificant CTPA, and formal echo performed. Right ventricular dysfunction was defined as RV hypokinesis and/or dilation with or without moderate to severe tricuspid regurgitation. RESULTS: A total of 7940 patients were enrolled. Two thousand six hundred sixteen patients were analyzed after excluding patients without persistent dyspnea and those with a significant finding on CTPA. One hundred ninety eight patients had echocardiography performed as standard care. Of those, 19% (95% confidence interval [CI], 14%-25%) and 33% (95% CI, 25%-42%) exhibited RV dysfunction and isolated RV dysfunction, respectively. Patients with isolated RV dysfunction or overload were more likely than those without RV dysfunction to have a return visit to the emergency department within 45 days for the same complaint (39% vs 18%; 95% CI of the difference, 4%-38%). CONCLUSION: This simple clinical prediction rule predicted a 33% prevalence of isolated RV dysfunction or overload. Patients with isolated RV dysfunction had higher recidivism rates and a trend toward worse outcomes.
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    Outpatient treatment of low-risk venous thromboembolism with monotherapy oral anticoagulation: patient quality of life outcomes and clinician acceptance
    (Dove Press, 2016-04-15) Kline, Jeffrey A.; Kahler, Zachary P.; Beam, Daren M.; Department of Emergency Medicine, IU School of Medicine
    BACKGROUND: Oral monotherapy anticoagulation has facilitated home treatment of venous thromboembolism (VTE) in outpatients. OBJECTIVES: The aim of this study was to measure efficacy, safety, as well as patient and physician perceptions produced by a protocol that selected VTE patients as low-risk patients by the Hestia criteria, and initiated home anticoagulation with an oral factor Xa antagonist. METHODS: Patients were administered the Venous Insufficiency Epidemiological and Economic Study Quality of life/Symptoms questionnaire [VEINEs QoL/Sym] and the physical component summary [PCS] from the Rand 36-Item Short Form Health Survey [SF36]). The primary outcomes were VTE recurrence and hemorrhage at 30 days. Secondary outcomes compared psychometric test scores between patients with deep vein thrombosis (DVT) to those with pulmonary embolism (PE). Patient perceptions were abstracted from written comments and physician perceptions specific to PE outpatient treatment obtained from structured survey. RESULTS: From April 2013 to September 2015, 253 patients were treated, including 67 with PE. Within 30 days, 2/253 patients had recurrent DVT and 2/253 had major hemorrhage; all four had DVT at enrollment. The initial PCS scores did not differ between DVT and PE patients (37.2±13.9 and 38.0±12.1, respectively) and both DVT and PE patients had similar improvement over the treatment period (42.2±12.9 and 43.4±12.7, respectively), consistent with prior literature. The most common adverse event was menorrhagia, present in 15% of women. Themes from patient-written responses reflected satisfaction with increased autonomy. Physicians' (N=116) before-to-after protocol comfort level with home treatment of PE increased 48% on visual analog scale. CONCLUSION: Hestia-negative VTE patients treated with oral monotherapy at home had low rates of VTE recurrence and bleeding, as well as quality of life measurements similar to prior reports.
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    The resistance of swine blood clots to alteplase-induced thrombolysis in vitro is concentration-dependent
    (Elsevier, 2021) Neto-Neves, Evandro M.; Beam, Daren M.; Kline, Jeffrey A.; Emergency Medicine, School of Medicine
    Background: Swine have been used as a large animal translational research model to investigate the effectiveness of fibrinolytic agents. However, swine thrombi have different characteristics than human thrombi, which may confer more resistance to fibrinolysis. Methods: In this study, we performed an in-vitro clot lysis assay to compare both human and swine blood clots lysis induced by alteplase, a recombinant tissue plasminogen-activator agent. Human and swine whole blood were allowed to clot for 3 ​h at 37 ​°C. Increasing concentrations of alteplase (250–580,000 IU/mL) or phosphate-buffered saline (PBS, pH 7.4) were added into the clots. Clot lysis was determined by calculating the difference between the clot mass pre- and post-lysis. Results: At low alteplase concentrations (250–2000 IU/mL) we observed significantly less swine blood clot lysis (14 ​± ​1.7% - 35 ​± ​4.9%) compared to the lysis found to human blood clots (52 ​± ​4.8% - 68 ​± ​3.3%, ∗p ​< ​0.05). In contrast, we did not find lysis differences between human and swine clots at higher alteplase concentrations (5000–580,000 IU/mL). Conclusions: In conclusion, our results suggest that the swine clot resistance to alteplase-induced thrombolysis is concentration-dependent. A high concentration of alteplase allows equivalent thrombolysis of swine and human blood clots in vitro.