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INTRODUCTION: Electrocardiographic characteristics in COVID-19-related mortality have not yet been reported, particularly in racial/ethnic minorities. METHODS AND RESULTS: We reviewed demographics, laboratory and cardiac tests, medications, and cardiac rhythm proximate to death or initiation of comfort care for patients hospitalized with a positive SARS-CoV-2 reverse-transcriptase polymerase chain reaction in three New York City hospitals between March 1 and April 3, 2020 who died. We described clinical characteristics and compared factors contributing toward arrhythmic versus nonarrhythmic death. Of 1258 patients screened, 133 died and were enrolled. Of these, 55.6% (74/133) were male, 69.9% (93/133) were racial/ethnic minorities, and 88.0% (117/133) had cardiovascular disease. The last cardiac rhythm recorded was VT or fibrillation in 5.3% (7/133), pulseless electrical activity in 7.5% (10/133), unspecified bradycardia in 0.8% (1/133), and asystole in 26.3% (35/133). Most 74.4% (99/133) died receiving comfort measures only. The most common abnormalities on admission electrocardiogram included abnormal QRS axis (25.8%), atrial fibrillation/flutter (14.3%), atrial ectopy (12.0%), and right bundle branch block (11.9%). During hospitalization, an additional 17.6% developed atrial ectopy, 14.7% ventricular ectopy, 10.1% atrial fibrillation/flutter, and 7.8% a right ventricular abnormality. Arrhythmic death was confirmed or suspected in 8.3% (11/133) associated with age, coronary artery disease, asthma, vasopressor use, longer admission corrected QT interval, and left bundle branch block (LBBB). CONCLUSIONS: Conduction, rhythm, and electrocardiographic abnormalities were common during COVID-19-related hospitalization. Arrhythmic death was associated with age, coronary artery disease, asthma, longer admission corrected QT interval, LBBB, ventricular ectopy, and usage of vasopressors. Most died receiving comfort measures.
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Arritmias Cardíacas/mortalidade , COVID-19/mortalidade , Mortalidade Hospitalar , Idoso , Idoso de 80 Anos ou mais , Arritmias Cardíacas/diagnóstico , Arritmias Cardíacas/etnologia , Arritmias Cardíacas/terapia , COVID-19/diagnóstico , COVID-19/etnologia , COVID-19/terapia , Causas de Morte , Comorbidade , Eletrocardiografia , Feminino , Fatores de Risco de Doenças Cardíacas , Mortalidade Hospitalar/etnologia , Hospitalização , Humanos , Masculino , Pessoa de Meia-Idade , Cidade de Nova Iorque/epidemiologia , Prognóstico , Fatores Raciais , Estudos Retrospectivos , Medição de Risco , Fatores de TempoRESUMO
A global coronavirus (COVID-19) pandemic occurred at the start of 2020 and is already responsible for more than 74 000 deaths worldwide, just over 100 years after the influenza pandemic of 1918. At the center of the crisis is the highly infectious and deadly SARS-CoV-2, which has altered everything from individual daily lives to the global economy and our collective consciousness. Aside from the pulmonary manifestations of disease, there are likely to be several electrophysiologic (EP) sequelae of COVID-19 infection and its treatment, due to consequences of myocarditis and the use of QT-prolonging drugs. Most crucially, the surge in COVID-19 positive patients that have already overwhelmed the New York City hospital system requires conservation of hospital resources including personal protective equipment (PPE), reassignment of personnel, and reorganization of institutions, including the EP laboratory. In this proposal, we detail the specific protocol changes that our EP department has adopted during the COVID-19 pandemic, including performance of only urgent/emergent procedures, after hours/7-day per week laboratory operation, single attending-only cases to preserve PPE, appropriate use of PPE, telemedicine and video chat follow-up appointments, and daily conferences to collectively manage the clinical and ethical dilemmas to come. We discuss also discuss how we perform EP procedures on presumed COVID positive and COVID tested positive patients to highlight issues that others in the EP community may soon face in their own institution as the virus continues to spread nationally and internationally.
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Centros Médicos Acadêmicos/provisão & distribuição , Betacoronavirus , Infecções por Coronavirus/diagnóstico , Eletrofisiologia/métodos , Equipamento de Proteção Individual/normas , Pneumonia Viral/diagnóstico , COVID-19 , Humanos , Pandemias , SARS-CoV-2RESUMO
BACKGROUND: The COVID-19 pandemic has greatly altered the practice of cardiac electrophysiology around the world for the foreseeable future. Professional organizations have provided guidance for practitioners, but real-world examples of the consults and responsibilities cardiac electrophysiologists face during a surge of COVID-19 patients is lacking. METHODS: In this observational case series we report on 29 consecutive inpatient electrophysiology consultations at a major academic medical center in New York City, the epicenter of the pandemic in the United States, during a 2 week period from March 30-April 12, 2020, when 80% of hospital beds were occupied by COVID-19 patients, and the New York City metropolitan area accounted for 10% of COVID-19 cases worldwide. RESULTS: Reasons for consultation included: Atrial tachyarrhythmia (31%), cardiac implantable electronic device management (28%), bradycardia (14%), QTc prolongation (10%), ventricular arrhythmia (7%), post-transcatheter aortic valve replacement conduction abnormality (3.5%), ventricular pre-excitation (3.5%), and paroxysmal supraventricular tachycardia (3.5%). Twenty-four patients (86%) were positive for COVID-19 by nasopharyngeal swab. All elective procedures were canceled, and only one urgent device implantation was performed. Thirteen patients (45%) required in-person evaluation and the remainder were managed remotely. CONCLUSION: Our experience shows that the application of a massive alteration in workflow and personnel forced by the pandemic allowed our team to efficiently address the intersection of COVID-19 with a range of electrophysiology issues. This experience will prove useful as guidance for emerging hot spots or areas affected by future waves of the pandemic.
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Background and Purpose- Atrial fibrillation (AF) is associated with dementia independent of clinical stroke. The mechanisms underlying this association remain unclear. In a community-based cohort, the ARIC study (Atherosclerosis Risk in Communities), we evaluated (1) the longitudinal association of incident AF and (2) the cross-sectional association of prevalent AF with brain magnetic resonance imaging (MRI) abnormalities. Methods- The longitudinal analysis included 963 participants (mean age, 73±4.4 years; 62% women; 51% black) without prevalent stroke or AF who underwent a brain MRI in 1993 to 1995 and a second MRI in 2004 to 2006 (mean, 10.6±0.8 years). Outcomes included subclinical cerebral infarctions, sulcal size, ventricular size, and, for the cross-sectional analysis, white matter hyperintensity volume and total brain volume. Results- In the longitudinal analysis, 29 (3.0%) participants developed AF after the first brain MRI. Those who developed AF had higher odds of increase in subclinical cerebral infarctions (odds ratio [OR], 3.08; 95% CI, 1.39-6.83), worsening sulcal grade (OR, 3.56; 95% CI, 1.04-12.2), and worsening ventricular grade (OR, 9.34; 95% CI, 1.24-70.2). In cross-sectional analysis, of 969 participants, 35 (3.6%) had prevalent AF at the time of the 2004 to 2006 MRI scan. Those with AF had greater odds of higher sulcal (OR, 3.9; 95% CI, 1.7-9.1) and ventricular grade (OR, 2.4; 95% CI, 1.0-5.7) after multivariable adjustment and no difference in white matter hyperintensity or total brain volume. Conclusions- AF is independently associated with increase in subclinical cerebral infarction and worsening sulcal and ventricular grade-morphological changes associated with aging and dementia. More research is needed to define the mechanisms underlying AF-related neurodegeneration.
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Fibrilação Atrial/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Demência/diagnóstico por imagem , Idoso , Estudos Transversais , Feminino , Humanos , Estudos Longitudinais , Imageamento por Ressonância Magnética , Masculino , Tamanho do Órgão/fisiologia , Fatores de Risco , Substância Branca/diagnóstico por imagemRESUMO
INTRODUCTION: Cardiovascular disease is the most common cause of morbidity and mortality worldwide. Inflammation is responsible for initiation and progression of atherosclerosis, and leads to plaque vulnerability. Evidence-based therapies reduce the risk of initial and recurrent cardiovascular events but many patients experience recurrent events due to the failure of conventional therapies to adequately address inflammation. AREAS COVERED: Statins were originally developed for their LDL cholesterol-lowering effects, but are now thought to improve cardiovascular morbidity and mortality through anti-inflammatory effects as well. Drugs that inhibit the various inflammatory pathways responsible for atherosclerosis are the subject of current research. These include antioxidants, phospholipase A(2) inhibitors, leukotriene pathway inhibitors, CCL2-CCR2 pathway inhibitors, non-specific anti-inflammatory drugs (i.e., methotrexate), IL-1 inhibitors and p-selectin inhibitors. EXPERT OPINION: Currently, only three anti-inflammatory drugs (methotrexate, darapladib and canakinumab) are being investigated in Phase III clinical trials of atherosclerosis. The development of cardiovascular drugs requires long, expensive Phase III trials to demonstrate incremental improvement in cardiovascular events. Imaging end points and soluble biomarkers accelerate Phase II development, but further validation is needed before these can be used as surrogate end points in the large trials leading to drug approval. Improved access to currently available therapies like statins would decrease the burden of cardiovascular disease worldwide.
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Anti-Inflamatórios/uso terapêutico , Aterosclerose/tratamento farmacológico , Animais , HumanosRESUMO
There is growing evidence that COVID-19 can cause cardiovascular complications. However, there are limited data on the characteristics and importance of atrial arrhythmia (AA) in patients hospitalized with COVID-19. Data from 1,029 patients diagnosed with of COVID-19 and admitted to Columbia University Medical Center between March 1, 2020 and April 15, 2020 were analyzed. The diagnosis of AA was confirmed by 12 lead electrocardiographic recordings, 24-hour telemetry recordings and implantable device interrogations. Patients' history, biomarkers and hospital course were reviewed. Outcomes that were assessed were intubation, discharge and mortality. Of 1,029 patients reviewed, 82 (8%) were diagnosed with AA in whom 46 (56%) were new-onset AA 16 (20%) recurrent paroxysmal and 20 (24%) were chronic persistent AA. Sixty-five percent of the patients diagnosed with AA (n=53) died. Patients diagnosed with AA had significantly higher mortality compared with those without AA (65% vs 21%; p < 0.001). Predictors of mortality were older age (Odds Ratio (OR)=1.12, [95% Confidence Interval (CI), 1.04 to 1.22]); male gender (OR=6.4 [95% CI, 1.3 to 32]); azithromycin use (OR=13.4 [95% CI, 2.14 to 84]); and higher D-dimer levels (OR=2.8 [95% CI, 1.1 to 7.3]). In conclusion, patients diagnosed with AA had 3.1 times significant increase in mortality rate versus patients without diagnosis of AA in COVID-19 patients. Older age, male gender, azithromycin use and higher baseline D-dimer levels were predictors of mortality.
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Fibrilação Atrial/epidemiologia , COVID-19/epidemiologia , Gerenciamento Clínico , Pandemias , Idoso , Idoso de 80 Anos ou mais , COVID-19/terapia , Comorbidade , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , New York/epidemiologia , Estudos Retrospectivos , Fatores de Risco , SARS-CoV-2 , Índice de Gravidade de DoençaRESUMO
Importance: Critical illness, a marked inflammatory response, and viruses such as SARS-CoV-2 may prolong corrected QT interval (QTc). Objective: To evaluate baseline QTc interval on 12-lead electrocardiograms (ECGs) and ensuing changes among patients with and without COVID-19. Design, Setting, and Participants: This cohort study included 3050 patients aged 18 years and older who underwent SARS-CoV-2 testing and had ECGs at Columbia University Irving Medical Center from March 1 through May 1, 2020. Patients were analyzed by treatment group over 5 days, as follows: hydroxychloroquine with azithromycin, hydroxychloroquine alone, azithromycin alone, and neither hydroxychloroquine nor azithromycin. ECGs were manually analyzed by electrophysiologists masked to COVID-19 status. Multivariable modeling evaluated clinical associations with QTc prolongation from baseline. Exposures: COVID-19, hydroxychloroquine, azithromycin. Main Outcomes and Measures: Mean QTc prolongation, percentage of patients with QTc of 500 milliseconds or greater. Results: A total of 965 patients had more than 2 ECGs and were included in the study, with 561 (58.1%) men, 198 (26.2%) Black patients, and 191 (19.8%) aged 80 years and older. There were 733 patients (76.0%) with COVID-19 and 232 patients (24.0%) without COVID-19. COVID-19 infection was associated with significant mean QTc prolongation from baseline by both 5-day and 2-day multivariable models (5-day, patients with COVID-19: 20.81 [95% CI, 15.29 to 26.33] milliseconds; P < .001; patients without COVID-19: -2.01 [95% CI, -17.31 to 21.32] milliseconds; P = .93; 2-day, patients with COVID-19: 17.40 [95% CI, 12.65 to 22.16] milliseconds; P < .001; patients without COVID-19: 0.11 [95% CI, -12.60 to 12.81] milliseconds; P = .99). COVID-19 infection was independently associated with a modeled mean 27.32 (95% CI, 4.63-43.21) millisecond increase in QTc at 5 days compared with COVID-19-negative status (mean QTc, with COVID-19: 450.45 [95% CI, 441.6 to 459.3] milliseconds; without COVID-19: 423.13 [95% CI, 403.25 to 443.01] milliseconds; P = .01). More patients with COVID-19 not receiving hydroxychloroquine and azithromycin had QTc of 500 milliseconds or greater compared with patients without COVID-19 (34 of 136 [25.0%] vs 17 of 158 [10.8%], P = .002). Multivariable analysis revealed that age 80 years and older compared with those younger than 50 years (mean difference in QTc, 11.91 [SE, 4.69; 95% CI, 2.73 to 21.09]; P = .01), severe chronic kidney disease compared with no chronic kidney disease (mean difference in QTc, 12.20 [SE, 5.26; 95% CI, 1.89 to 22.51; P = .02]), elevated high-sensitivity troponin levels (mean difference in QTc, 5.05 [SE, 1.19; 95% CI, 2.72 to 7.38]; P < .001), and elevated lactate dehydrogenase levels (mean difference in QTc, 5.31 [SE, 2.68; 95% CI, 0.06 to 10.57]; P = .04) were associated with QTc prolongation. Torsades de pointes occurred in 1 patient (0.1%) with COVID-19. Conclusions and Relevance: In this cohort study, COVID-19 infection was independently associated with significant mean QTc prolongation at days 5 and 2 of hospitalization compared with day 0. More patients with COVID-19 had QTc of 500 milliseconds or greater compared with patients without COVID-19.
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Azitromicina , Tratamento Farmacológico da COVID-19 , COVID-19 , Eletrocardiografia , Hidroxicloroquina , Síndrome do QT Longo , Idoso de 80 Anos ou mais , Anti-Infecciosos/administração & dosagem , Anti-Infecciosos/efeitos adversos , Azitromicina/administração & dosagem , Azitromicina/efeitos adversos , COVID-19/diagnóstico , COVID-19/epidemiologia , Teste para COVID-19/métodos , Quimioterapia Combinada/métodos , Quimioterapia Combinada/estatística & dados numéricos , Eletrocardiografia/métodos , Eletrocardiografia/estatística & dados numéricos , Feminino , Hospitalização/estatística & dados numéricos , Humanos , Hidroxicloroquina/administração & dosagem , Hidroxicloroquina/efeitos adversos , Síndrome do QT Longo/induzido quimicamente , Síndrome do QT Longo/diagnóstico , Síndrome do QT Longo/epidemiologia , Síndrome do QT Longo/virologia , Masculino , Pessoa de Meia-Idade , New York/epidemiologia , Avaliação de Processos e Resultados em Cuidados de Saúde , Fatores de Risco , SARS-CoV-2 , Fatores de TempoRESUMO
PURPOSE: The goal of this study was to investigate the effects of silencing HIF-1 alpha gene expression with specific small interfering RNA (siRNA) on VEGF production and angiogenesis in epithelial ovarian cancer (EOC) cells. METHODS: Two EOC cell lines, MDAH-2774 and SKOV-3, were cultured under normoxic (20% O(2)) and hypoxic (2% O(2)) conditions using standard techniques. After EOC cells were transfected with siRNA, HIF-1 alpha and VEGF mRNA levels were measured by real-time RT-PCR. Angiogenesis was evaluated utilizing an in vitro assay model consisting of human umbilical vein endothelial cells (HUVEC) and polymerized ECM Matrix. RESULTS: Both EOC cell lines evaluated constitutively expressed HIF-1 alpha and VEGF mRNA. HIF-1 alpha and VEGF mRNA levels were significantly increased in response to hypoxia (P < 0.05). Under hypoxic conditions, inhibition of HIF-1 alpha gene expression by a specific siRNA resulted in a significant reduction in HIF-1 alpha and VEGF mRNA levels (P < 0.05). In the in vitro angiogenesis model, supernatant from the hypoxic EOC cells induced the HUVEC to form a complex tubular network, a hallmark of angiogenesis. Semi-quantitative analysis of the angiogenesis assay revealed a significant reduction in tube formation when supernatant from HIF-1 alpha siRNA-treated hypoxic EOC cell was used (P < 0.05). CONCLUSION: Inhibition of HIF-1 alpha expression by specific siRNA resulted in a significant decrease in VEGF production and angiogenesis. Further investigation of HIF-1 alpha inhibition for anti-tumor activity is warranted and may potentially prove HIF-1 alpha as a therapeutic target in the management ovarian cancer.
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Subunidade alfa do Fator 1 Induzível por Hipóxia/antagonistas & inibidores , Neovascularização Patológica/tratamento farmacológico , Neoplasias Ovarianas/tratamento farmacológico , RNA Interferente Pequeno/uso terapêutico , Fator A de Crescimento do Endotélio Vascular/metabolismo , Linhagem Celular Tumoral , Avaliação Pré-Clínica de Medicamentos , Feminino , Expressão Gênica/efeitos dos fármacos , Humanos , Hipóxia/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Neoplasias Ovarianas/metabolismo , Interferência de RNA , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/farmacologiaRESUMO
The coronavirus disease 2019 crisis is a global pandemic of a novel infectious disease with far-ranging public health implications. With regard to cardiac electrophysiology (EP) services, we discuss the "real-world" challenges and solutions that have been essential for efficient and successful (1) ramping down of standard clinical practice patterns and (2) pivoting of workflow processes to meet the demands of this pandemic. The aims of these recommendations are to outline: (1) essential practical steps to approaching procedures, as well as outpatient and inpatient care of EP patients, with relevant examples, (2) successful strategies to minimize exposure risk to patients and clinical staff while also balancing resource utilization, (3) challenges related to redeployment and restructuring of clinical and support staff, and (4) considerations regarding continued collaboration with clinical and administrative colleagues to implement these changes. While process changes will vary across practices and hospital systems, we believe that these experiences from 4 different EP sections in a large New York City hospital network currently based in the global epicenter of the coronavirus disease 2019 pandemic will prove useful for other EP practices adapting their own practices in preparation for local surges.
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Assistência Ambulatorial/tendências , Eletrofisiologia Cardíaca , Infecções por Coronavirus , Reestruturação Hospitalar , Controle de Infecções , Pandemias , Administração dos Cuidados ao Paciente , Pneumonia Viral , Telemedicina/tendências , Betacoronavirus/isolamento & purificação , COVID-19 , Eletrofisiologia Cardíaca/métodos , Eletrofisiologia Cardíaca/organização & administração , Eletrofisiologia Cardíaca/tendências , Gestão de Mudança , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/terapia , Procedimentos Clínicos/tendências , Reestruturação Hospitalar/métodos , Reestruturação Hospitalar/organização & administração , Hospitalização/tendências , Hospitais Urbanos/organização & administração , Humanos , Controle de Infecções/métodos , Controle de Infecções/organização & administração , Cidade de Nova Iorque , Administração dos Cuidados ao Paciente/métodos , Administração dos Cuidados ao Paciente/organização & administração , Administração dos Cuidados ao Paciente/tendências , Pneumonia Viral/epidemiologia , Pneumonia Viral/terapia , SARS-CoV-2RESUMO
Adverse drug events are common during the transition period after hospitalization, and anticoagulants are among the medication classes for which the incidence is highest. We aimed to develop a concise report to improve the timeliness of international normalized ratio (INR) testing and quality of warfarin management posthospitalization. We developed the Safe Transitions Anticoagulation Report (STAR), which contains essential information on anticoagulation and is embedded in the discharge summary, and implemented the report and associated workflow in a tertiary care hospital within an integrated healthcare system. We performed a retrospective administrative database review of 505 patients in the preintervention period and 292 patients in the intervention period who were discharged on warfarin and were established patients at an affiliated ambulatory practice. There was no change in the frequency of obtaining an INR value within 10 days of discharge (41.4% and 47.6%, respectively, P = 0.09), and no increase in attaining a therapeutic INR level within 10 days of discharge (17.0% and 21.2%, respectively, P = 0.14). Ambulatory clinicians reported that the STAR improved "workflow and efficiency" (58%) and "patient safety" (77%), and led to an altered warfarin dose for 34% of survey respondents. Our study found that a concise anticoagulation report embedded in the discharge summary was perceived by ambulatory physicians as improving patient safety, but had no impact on clinical outcomes, suggesting that this electronic medical record tool would need to be a component of a broader multifaceted intervention to be effective.
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Anticoagulantes/uso terapêutico , Sumários de Alta do Paciente Hospitalar/normas , Varfarina/uso terapêutico , Idoso , Assistência Ambulatorial , Anticoagulantes/efeitos adversos , Atitude do Pessoal de Saúde , Feminino , Hospitalização , Humanos , Coeficiente Internacional Normatizado/métodos , Masculino , Pessoa de Meia-Idade , Segurança do Paciente , Médicos de Atenção Primária , Estudos Retrospectivos , Varfarina/efeitos adversosRESUMO
Patients with atrial fibrillation (AF) face an elevated risk of stroke compared with patients who have normal sinus rhythm. Warfarin, an oral vitamin K antagonist, is a highly effective therapeutic agent to reduce stroke risk in patients with AF; however, use of warfarin is complicated by variable patient dose response due to genetic factors and multiple food-drug and drug-drug interactions. Novel oral anticoagulants appear to be a safe, effective alternative to warfarin therapy without the need for routine coagulation monitoring. Dabigatran, a direct thrombin inhibitor, has been commercially available since 2010 for prevention of stroke in patients with nonvalvular AF. More recently, the US Food and Drug Administration (FDA) approved 2 oral activated factor X inhibitors, rivaroxaban and apixaban, for stroke prevention in patients with AF based on clinical trial evidence of their safety and efficacy. In this article, we provide an overview of the 3 novel oral anticoagulants for treating patients with AF and discuss the latest findings from subgroup analyses.
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Fibrilação Atrial/tratamento farmacológico , Benzimidazóis/uso terapêutico , Morfolinas/uso terapêutico , Pirazóis/uso terapêutico , Piridonas/uso terapêutico , Acidente Vascular Cerebral/prevenção & controle , Tiofenos/uso terapêutico , Varfarina/uso terapêutico , beta-Alanina/análogos & derivados , Administração Oral , Envelhecimento , Anticoagulantes/administração & dosagem , Anticoagulantes/efeitos adversos , Anticoagulantes/uso terapêutico , Antitrombinas/uso terapêutico , Fibrilação Atrial/complicações , Benzimidazóis/administração & dosagem , Benzimidazóis/efeitos adversos , Ensaios Clínicos como Assunto , Comorbidade , Dabigatrana , Hemorragia/induzido quimicamente , Humanos , Metanálise como Assunto , Morfolinas/administração & dosagem , Morfolinas/efeitos adversos , Pirazóis/administração & dosagem , Pirazóis/efeitos adversos , Piridonas/administração & dosagem , Piridonas/efeitos adversos , Medição de Risco/métodos , Rivaroxabana , Acidente Vascular Cerebral/tratamento farmacológico , Acidente Vascular Cerebral/etiologia , Tiofenos/administração & dosagem , Tiofenos/efeitos adversos , Varfarina/administração & dosagem , Varfarina/efeitos adversos , beta-Alanina/administração & dosagem , beta-Alanina/efeitos adversos , beta-Alanina/uso terapêuticoRESUMO
OBJECTIVES: Increases in emergency department (ED) visits may place a substantial burden on both the ED and hospital-based laboratories. Studies have identified laboratory turnaround time (TAT) as a barrier to patient process times and lengths of stay. Prolonged laboratory study results may also result in delayed recognition of critically ill patients and initiation of appropriate therapies. The objective of this study was to determine how ED patient volume itself is associated with laboratory TAT. METHODS: This was a retrospective cohort review of patients at five academic, tertiary care EDs in the United States. Data were collected on all adult patients seen in each ED with troponin laboratory testing during the months of January, April, July, and October 2007. Primary predictor variables were two ED patient volume measures at the time the troponin test was ordered: 1) number of all patients in the ED/number of beds (occupancy) and 2) number of admitted patients waiting for beds/beds (boarder occupancy). The outcome variable was troponin turnaround time (TTAT). Adjusted covariates included patient characteristics, triage severity, season (month of the laboratory test), and site. Multivariable adjusted quantile regression was carried out to assess the association of ED volume measures with TTAT. RESULTS: At total of 9,492 troponin tests were reviewed. Median TTAT for this cohort was 107 minutes (interquartile range [IQR] = 73-148 minutes). Median occupancy for this cohort was 1.05 patients (IQR = 0.78-1.38 patients) and median boarder occupancy was 0.21 (IQR = 0.11-0.32). Adjusted quantile regression demonstrated a significant association between increased ED patient volume and longer times to TTAT. For every 100% increase in census, or number of boarders over the number of ED beds, respectively, there was a 12 (95% confidence interval [CI] = 9 to 14) or 33 (95% CI = 24 to 42)-minute increase in TTAT. CONCLUSIONS: Increased ED patient volume is associated with longer hospital laboratory processing times. Prolonged laboratory TAT may delay recognition of conditions in the acutely ill, potentially affecting clinician decision-making and the initiation of timely treatment. Use of laboratory TAT as a patient throughput measure and the study of factors associated with its prolonging should be further investigated.