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Critical care transport medicine (CCTM) teams are playing an increasing role in the care of patients in cardiogenic shock requiring mechanical circulatory support devices. Hence, it is important that CCTM providers are familiar with the pathophysiology of cardiogenic shock, the role of mechanical circulatory support, and the management of these devices in the transport environment. The intra-aortic balloon pump is a widely used and accessible cardiac support device capable of increasing cardiac output and reducing work on the left ventricle through diastolic augmentation and counterpulsation. This article reviews essential CCTM-based considerations for patients supported by intra-aortic balloon pump, including indications for placement, mechanics and physiology, potential issues during transport, and associated complications.
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INTRODUCTION: Evidence suggests that Extracorporeal Cardiopulmonary Resuscitation (ECPR) can improve survival rates for nontraumatic out-of-hospital cardiac arrest (OHCA). However, when ECPR is indicated over 50% of potential candidates are unable to qualify in the current hospital-based system due to geographic limitations. This study employs a Geographic Information System (GIS) model to estimate the number of ECPR eligible patients within the United States in the current hospital-based system, a prehospital ECPR ground-based system, and a prehospital ECPR Helicopter Emergency Medical Services (HEMS)-based system. METHODS: We constructed a GIS model to estimate ground and helicopter transport times. Time-dependent rates of ECPR eligibility were derived from the Resuscitation Outcome Consortium (ROC) database, while the Cardiac Arrest Registry to Enhance Survival (CARES) registry determined the number of OHCA patients meeting ECPR criteria within designated transportation times. Emergency Medical Services (EMS) response time, ECPR candidacy determination time, and on-scene time were modeled based on data from the EROCA trial. The combined model was used to estimate the total ECPR eligibility in each system. RESULTS: The CARES registry recorded 736,066 OHCA patients from 2013 to 2021. After applying clinical criteria, 24,661 (3.4%) ECPR-indicated OHCA were identified. When considering overall ECPR eligibility within 45 min from OHCA to initiation, only 11.76% of OHCA where ECPR was indicated were eligible in the current hospital-based system. The prehospital ECPR HEMS-based system exhibited a four-fold increase in ECPR eligibility (49.3%), while the prehospital ground-based system showed a more than two-fold increase (28.4%). CONCLUSIONS: The study demonstrates a two-fold increase in ECPR eligibility for a prehospital ECPR ground-based system and a four-fold increase for a prehospital ECPR HEMS-based system compared to the current hospital-based ECPR system. This novel GIS model can inform future ECPR implementation strategies, optimizing systems of care.
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OBJECTIVE: Interhospital transfer by air (IHTA) represents the majority of helicopter air ambulance transports in the United States, but the evaluation of what factors are associated with utilization has been limited. We aimed to assess the association of geographic distance and hospital characteristics (including patient volume) with the use of IHTA. METHODS: This was a multicenter, retrospective study of helicopter flight request data from 2018 provided by a convenience sample of 4 critical care transport medicine programs in 3 US census regions. Nonfederal referring hospitals located in the home state of the associated critical care transport medicine program and within 100 miles of the primary receiving facility in the region were included if complete data were available. We fit a Poisson principal component regression model incorporating geographic distance, the number of emergency department visits, the number of hospital discharges, case mix index, the number of intensive care unit beds, and the number of general beds and tested the association of the variables with helicopter emergency medical services utilization. RESULTS: A total of 106 referring hospitals were analyzed, 21 of which were hospitals identified as having a consistent request pattern. Using the hospitals with a consistent referral pattern, geographic distance had a significant positive association with flight request volume. Other variables, including emergency department visit volume, were not associated. Overall, the included variables offered poor explanatory power for the observed variation between referring facilities in the use of IHTA (r2 = 0.09). Predicted flights based on the principal component regression model for all referring hospitals suggested the majority of referring hospitals used multiple flight programs. CONCLUSION: Geographic distance is associated with the use of IHTA. Unexpectedly, most basic hospital characteristics are not associated with the use of IHTA, and the degree of variation between referring facilities that is explained by patient volume is limited. The evaluation of nonhospital factors, such as the density and availability of critical care or advanced life support ground emergency medical services resources, is needed.
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Resgate Aéreo , Serviços Médicos de Emergência , Humanos , Estados Unidos , Estudos Retrospectivos , Hospitais , AeronavesRESUMO
Introduction: Consideration of the cost of care and value in healthcare is now a recognized element of physician training. Despite the urgency to educate trainees in high-value care (HVC), educational curricula and evaluation of these training paths remain limited, especially with respect to emergency medicine (EM) residents. We aimed to complete a needs assessment and evaluate curricular preferences for instruction on HVC among EM residents. Methods: This was a qualitative, exploratory study using content analysis of two focus groups including a total of eight EM residents from a single Midwestern EM residency training program. Participants also completed a survey questionnaire. Results: There were two themes. Within the overall theme of resident experience with and perception of HVC, we found five sub-themes: 1) understanding of HVC focuses on diagnosis and decision-making; 2) concern about patient costs, including the effects on patients' lives and their ability to engage with recommended outpatient care; 3) conflict between internal beliefs and external expectations, including patients' perceptions of value; 4) approach to HVC changes with increasing clinical experience; and 5) slow-moving, political discussion around HVC. Within the overall theme of desired education and curricular design, we identified four sub-themes: 1) limited prior education on HVC and health economics; 2) motivation to receive training on HVC and health economics; 3) desire for discussion-based format for HVC curriculum; and 4) curriculum targeted to level of training. Respondents indicated greatest acceptability of interactive, discussion-based formats. Discussion: We conducted a targeted needs assessment for HVC among EM residents. We identified broad interest in the topic and limited self-reported baseline knowledge. Curricular content may benefit from incorporating resident concerns about patient costs and conflict between external expectations and internal beliefs about HVC. Curricular design may benefit from a focus on interactive, discussion-based modalities and tailoring to the learner's level of training.
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Currículo , Medicina de Emergência , Humanos , Avaliação das Necessidades , Escolaridade , Assistência AmbulatorialRESUMO
OBJECTIVE: Lateral canthotomy is a rare, emergent, vision-preserving procedure to treat orbital compartment syndrome. Using Ericsson's deliberate practice model, we aimed to develop a multimodal small group intervention including a modified low-fidelity task trainer to improve flight physician knowledge and technical competency for lateral canthotomy in the prehospital context. METHODS: Two cohorts of resident (postgraduate year 1) flight physicians received small group training during an all-day competency-based flight physician orientation. The first cohort completed self-report pre- and postintervention assessments. In the second cohort, examiners assessed pre- and postintervention performance. RESULTS: Comparing pre- and postintervention responses (N = 27), the mean agreement with the knowledge of indications increased from 3.7 to 4.8. The mean agreement regarding confidence in skills increased from 2.2 to 4.2 (P < .001). The majority of participants (20/27) indicated the trainer "definitely helped," whereas 7 of 27 residents indicated the trainer "somewhat helped" them to learn skills. Examiners assessed holistic learner performance (n = 13) as improved from a mean of 3.2 preintervention to 4.7 postintervention, with 11 of 13 learners demonstrating improvement (P < .005). CONCLUSION: We demonstrate the feasibility of a brief small group training combining multimodal didactics with a modified low-fidelity task trainer. Resident self-assessment and examiner assessment demonstrated improved procedural skill with lateral canthotomy.
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Internato e Residência , Médicos , Humanos , Aprendizagem , Competência ClínicaRESUMO
INTRODUCTION: Placement of percutaneous ventricular support devices such as an intraaortic balloon pump (IABP) or Abiomed Impella device can treat severe cardiogenic shock. Critical care transport medicine (CCTM) providers frequently manage patients supported by these devices during interfacility transfers, often using a helicopter air ambulance (HAA). An understanding of patient needs and management during transport is essential to informing crew configuration and training, and this study adds to the limited existing data on the HAA transport of this complex patient population. METHODS: We performed a retrospective chart review of all HAA transports of patients with an IABP (n = 38) or Impella (n = 11) device at a single CCTM program from 2016 to 2020. We evaluated transport times and composite variables for the frequency of adverse events, condition changes requiring critical care evaluation, and critical care interventions. RESULTS: In this observational cohort, patients with an Impella device more frequently had an advanced airway and at least 1 vasopressor or inotrope active prior to transport. While flight times were similar, CCTM teams remained at referring facilities longer for patients with an Impella device (99 vs 68 minutes; p = 0.0097). Compared to patients with an IABP, patients with an Impella device more frequently had a condition change requiring critical care evaluation (100% vs 42%; p = 0.0005) and more frequently received critical care interventions (100% vs 53%; p = 0.0037). Adverse events were uncommon and did not differ for patients with an Impella device compared to an IABP (27% vs 11%; p = 0.178). CONCLUSION: Patients requiring mechanical circulatory support with IABP and Impella devices frequently require critical care management during transport. Clinicians should ensure the CCTM team has appropriate staffing, training, and resources to meet the critical care needs of these high acuity patients.
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BACKGROUND: Recent evidence suggest that extracorporeal cardiopulmonary resuscitation (ECPR) may improve survival rates for nontraumatic out-of-hospital cardiac arrest (OHCA). Eligibility criteria for ECPR are often based on patient age, clinical variables, and facility capabilities. Expanding access to ECPR across the U.S. requires a better understanding of how these factors interact with transport time to ECPR centers. METHODS: We constructed a Geographic Information System (GIS) model to estimate the number of ECPR candidates in the U.S. We utilized a Resuscitation Outcome Consortium (ROC) database to model time-dependent rates of ECPR eligibility and the Cardiac Arrest Registry to Enhance Survival (CARES) registry to determine the total number of OHCA patients who meet pre-specified ECPR criteria within designated transportation times. The combined model was used to estimate the total number of ECPR candidates. RESULTS: There were 588,203 OHCA patients in the CARES registry from 2013 to 2020. After applying clinical eligibility criteria, 22,104 (3.76%) OHCA patients were deemed eligible for ECPR. The rate of ROSC increased with longer resuscitation time, which resulted in fewer ECPR candidates. The proportion of OHCA patients eligible for ECPR increased with older age cutoffs. Only 1.68% (9,889/588,203) of OHCA patients in the U.S. were eligible for ECPR based on a 45-minute transportation time to an ECMO-ready center model. CONCLUSIONS: Less than 2% of OHCA patients are eligible for ECPR in the U.S. GIS models can identify the impact of clinical criteria, transportation time, and hospital capabilities on ECPR eligibility to inform future implementation strategies.
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OBJECTIVE: The aim of this study was to evaluate the feasibility of statin administration by a critical care transport medicine (CCTM) team during rotor wing transport for ST-elevation myocardial infarction patients to a percutaneous intervention-capable center. METHODS: We conducted a retrospective study at a single CCTM program after an intervention focused on statin administration for ST-elevation myocardial infarction that included a formulary change and a single brief educational presentation to flight physicians. A comparison group of flight nurse practitioners underwent training after the study period and were used as a control. Two authors completed an independent chart review to collect data. Descriptive statistics and chi-square or Mann-Whitney U testing were used to compare groups. RESULTS: Statin administration (or documentation of statin administration before CCTM crew arrival or contraindication to statin administration) occurred during 15 of 19 (79%) transports staffed by trained providers and 3 of 18 (17%) transports staffed by untrained providers (P < .001 by chi-square test). Scene times were not significantly different between transports by trained and untrained providers. CONCLUSION: In summary, we demonstrate the feasibility and safety of a protocol for statin administration in the CCTM setting.
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Inibidores de Hidroximetilglutaril-CoA Redutases , Intervenção Coronária Percutânea , Infarto do Miocárdio com Supradesnível do Segmento ST , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Estudos Retrospectivos , Resultado do TratamentoRESUMO
Emergency departments (EDs) are an important potential site for public health screening programs, although implementation of such programs can be challenging. Potential barriers include system-level issues (e.g., funding and time pressures) and individual provider-level issues (e.g., awareness and acceptance). This cross-sectional evaluation of a nurse-driven, triage-based hepatitis C virus (HCV) screening program in an urban, academic ED assessed variation in nurse participation from April to November 2017. For this program, electronic health record (EHR) prompts for HCV screening were integrated into nurses' triage workflow. Process measures evaluating HCV screening participation were abstracted from the EHR for all ED encounters with patient year of birth between 1945 and 1965. Registered nurses who routinely worked in triage and were full-time employees throughout the study period were included for analysis. The primary outcome was the proportion of eligible ED encounters with completed HCV screening, by nurse. Of 14,375 ED encounters, 3,375 (23.5%, 95% confidence interval [CI]: 22.8, 24.2) had completed HCV screening and 1,408 (9.8%, 95% CI: 3.9, 10.3) had HCV screening EHR sections opened by the triage nurse but closed without action; the remainder of encounters had no activity in HCV screening EHR sections. Among the 93 eligible nurses, 22 nurses (24%, 95% CI: 16, 34) completed HCV screening for more than 70% of encounters, whereas 10 nurses (11%, 95% CI: 6, 19) never completed HCV screening. The proportion of eligible encounters with completed HCV screening was 11.0% higher (95% CI: 9.8, 12.6) for encounters seen between 7 a.m. and 7 p.m. than between 7 p.m. and 7 a.m. (27.5% and 16.3%, respectively). In conclusion, wide variation in individual nurse participation in HCV screening suggests individual-level barriers are a more significant barrier to ED screening than previously recognized. Implementation research should expand beyond questions of resource availability and procedural streamlining to evaluate and address staff knowledge, beliefs, attitudes, and motivation.
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Serviço Hospitalar de Emergência , Hepatite C/diagnóstico , Programas de Rastreamento/enfermagem , Adulto , Estudos Transversais , Feminino , Humanos , Masculino , TriagemRESUMO
INTRODUCTION: Patients with opioid use disorder (OUD) are at increased risk for overdose and death. Clinical practice guidelines and professional organization policy statements recommend providing naloxone to patients at risk for overdose. We sought to characterize fidelity to naloxone practice recommendations in a cohort of Emergency Department (ED) patients in whom opioid use disorder was suspected by the treating physician. METHODS: This single-center cross-sectional study evaluated electronic health records from an urban academic ED with 73,000 annual encounters in a region with a high prevalence of OUD. Patients ≥18 years old with encounters from January 1, 2018 to November 30, 2019 were included if discharged from the ED and either administered buprenorphine in the ED or referred to outpatient substance use treatment. The primary outcome measure was the percentage of included patients provided naloxone (take-home or prescription). We used random effects multivariable logistic regression (accounting for multiple patient encounters) to estimate the odds ratio (OR) for receiving naloxone. RESULTS: Of 1036 eligible patient encounters, 320 resulted in naloxone provision (30.9%, 95% CI: 28.1-33.8). Naloxone provision occurred for 33.6% (95% CI 30.5-36.7) of 900 patients referred to outpatient substance use treatment without ED buprenorphine administration, 10.6% (95% CI 5.0-19.2) of 85 patients administered buprenorphine and not referred to outpatient substance use treatment, and 17.6% (95% CI 8.4-30.9) of 51 patients administered buprenorphine and referred to outpatient treatment. After controlling for age, sex, race, and prior provision of naloxone, the administration of buprenorphine was associated with a 94% lower odds (aOR = 0.06 [95% CI 0.011-0.33]) for naloxone provision compared to those only referred to outpatient treatment. CONCLUSION: A majority of ED patients who received an intervention targeted at OUD, in an ED where take-home naloxone is freely available, did not receive either take-home naloxone or a prescription for naloxone at discharge. Patients receiving buprenorphine were less likely to receive naloxone than patients only referred to outpatient treatment. These data suggest barriers other than recognition of potential OUD and naloxone availability impact provision of naloxone and argue for a treatment "bundle" as a conceptual model for care of ED patients with suspected OUD.
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Overdose de Drogas/tratamento farmacológico , Serviço Hospitalar de Emergência , Naloxona/uso terapêutico , Antagonistas de Entorpecentes/uso terapêutico , Transtornos Relacionados ao Uso de Opioides/tratamento farmacológico , Padrões de Prática Médica/estatística & dados numéricos , Adulto , Estudos Transversais , Feminino , Hospitais Urbanos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos RetrospectivosRESUMO
INTRODUCTION: Emergency department encounters are an opportunity to distribute naloxone kits to patients at risk of opioid overdose. Several programs cite mixed uptake and implementation barriers including staff education and burden. Emergency nurses can facilitate many approaches to naloxone distribution (eg, prescription, overdose education, dispensing take-home naloxone). To evaluate acceptance, we investigated nurse perceptions about take-home naloxone, describing potential barriers to program implementation. METHODS: This qualitative study enrolled 17 emergency nurses from an urban trauma center emergency department and affiliated community emergency department. During the study period, nurses in both sites could distribute take-home naloxone kits stocked in the medication dispensing system. We conducted 12 individual, in-depth interviews and 3 distinct focus groups involving 12 nurses in aggregate. A semistructured interview guide was used with a range of topics surrounding pain management, addiction, opioid overdose, and emergency care. We employed conventional content analysis to enable thematic analysis of transcripts. RESULTS: Six component themes emerged as part of the overarching theme "mixed feelings about naloxone-morally distressing." One positive theme identified naloxone as an opportunity for discussion. Negative themes included (1) Addiction is a choice, why can't we help other diseases? It's unfair; (2) Providing naloxone enables and condones the behavior; (3) Emergency departments cannot treat social issues; (4) Patients can't give it to themselves; it's wasting money; and (5) Moral distress. DISCUSSION: Perceptions and moral distress may be a barrier to ED-based take-home naloxone programs. Development of interventions targeting naloxone misperceptions and addiction stigma should be a goal of expanded implementation efforts.
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Atitude do Pessoal de Saúde , Overdose de Drogas/tratamento farmacológico , Enfermagem em Emergência , Serviço Hospitalar de Emergência/organização & administração , Naloxona/administração & dosagem , Antagonistas de Entorpecentes/administração & dosagem , Transtornos Relacionados ao Uso de Opioides/tratamento farmacológico , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pesquisa QualitativaRESUMO
OBJECTIVES: Routine emergency department (ED) HIV or HCV screening may inadvertently capture patients already diagnosed but does not specifically prioritize identification of this group. Our objective was to preliminarily estimate the volume of this distinct group in our ED population through a pilot electronic health record (EHR) build that identified all patients with indications of HIV or HCV in their EHR at time of ED presentation. METHODS: Cross-sectional study of an urban, academic ED's HIV/HCV program for previously diagnosed patients August 2017-July 2018. Prevention program staff, alerted by the EHR, reviewed records and interviewed patients to determine if confirmatory testing or linkage to care was needed. Primary outcome was total proportion of ED patients for whom the EHR generated an alert. Secondary outcome was the proportion of patients assessed by program staff who required confirmatory testing or linkage to HIV/HCV medical care. RESULTS: There were 65,374 ED encounters with 5238 (8.0%, 95% CI: 7.8%-8.2%) EHR alerts. Of these, 3741 were assessed by program staff, with 798 (21%, 95% CI: 20%-23%) requiring HIV/HCV confirmatory testing or linkage to care services, 163 (20%) for HIV, 551 (69%) for HCV, and 84 (11%) for both HIV and HCV services. CONCLUSIONS: Patients with existing indication of HIV or HCV infection in need of confirmatory testing or linkage to care were common in this ED. EDs should prioritize identifying this population, outside of routine screening, and intervene similarly regardless of whether the patient is newly or previously diagnosed.
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Infecções por HIV/diagnóstico , Necessidades e Demandas de Serviços de Saúde , Hepatite C/diagnóstico , Programas de Rastreamento/métodos , Adulto , Estudos Transversais , Registros Eletrônicos de Saúde , Serviço Hospitalar de Emergência , Feminino , Infecções por HIV/epidemiologia , Hepatite C/epidemiologia , Humanos , Masculino , Projetos Piloto , Estudo de Prova de Conceito , Testes SorológicosRESUMO
BACKGROUND: Demographic shifts and care delivery system evolution affect the number of Emergency Department (ED) visits and associated costs. Recent aggregate trends in ED visit rates and charges between 2010 and 2016 have not been evaluated. METHODS: Data from the National Emergency Department Sample, comprising approximately 30 million annual patient visits, were used to estimate the ED visit rate and charges per visit from 2010 to 2016. ED visits were grouped into 144 mutually exclusive clinical categories. Visit rates, compound annual growth rates (CAGRs), and per visit charges were estimated. RESULTS: From 2010 to 2016, the number of ED visits increased from 128.97 million to 144.82 million; the cumulative growth was 12.29% and the CAGR was 1.95%, while the population grew at a CAGR of 0.73%. Expressed as a population rate, ED visits per 1000 persons increased from 416.92 in 2010 to 448.19 in 2016 (p value <0.001). The mean charges per visit increased from $2061 (standard deviation $2962) in 2010 to $3516 (standard deviation $2962) in 2016; the CAGR was 9.31% (p value <0.001). Of 144 clinical categories, 140 categories had a CAGR for mean charges per visit of at least 5%. CONCLUSION: The rate of ED visits per 1000 persons and the mean charge per ED visit increased significantly between 2010 and 2016. Mean charges increased for both high- and low-acuity clinical categories. Visits for the 5 most common clinical categories comprise about 30% of ED visits, and may represent focus areas for increasing the value of ED care.
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Serviço Hospitalar de Emergência/economia , Preços Hospitalares/tendências , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Estados Unidos , Revisão da Utilização de Recursos de SaúdeRESUMO
IMPORTANCE: The effect of surgical complications on hospital finances is unclear. OBJECTIVE: To determine the relationship between major surgical complications and per-encounter hospital costs and revenues by payer type. DESIGN, SETTING, AND PARTICIPANTS: Retrospective analysis of administrative data for all inpatient surgical discharges during 2010 from a nonprofit 12-hospital system in the southern United States. Discharges were categorized by principal procedure and occurrence of 1 or more postsurgical complications, using International Classification of Diseases, Ninth Revision, diagnosis and procedure codes. Nine common surgical procedures and 10 major complications across 4 payer types were analyzed. Hospital costs and revenue at discharge were obtained from hospital accounting systems and classified by payer type. MAIN OUTCOMES AND MEASURES: Hospital costs, revenues, and contribution margin (defined as revenue minus variable expenses) were compared for patients with and without surgical complications according to payer type. RESULTS: Of 34,256 surgical discharges, 1820 patients (5.3%; 95% CI, 4.4%-6.4%) experienced 1 or more postsurgical complications. Compared with absence of complications, complications were associated with a $39,017 (95% CI, $20,069-$50,394; P < .001) higher contribution margin per patient with private insurance ($55,953 vs $16,936) and a $1749 (95% CI, $976-$3287; P < .001) higher contribution margin per patient with Medicare ($3629 vs $1880). For this hospital system in which private insurers covered 40% of patients (13,544), Medicare covered 45% (15,406), Medicaid covered 4% (1336), and self-payment covered 6% (2202), occurrence of complications was associated with an $8084 (95% CI, $4903-$9740; P < .001) higher contribution margin per patient ($15,726 vs $7642) and with a $7435 lower per-patient total margin (95% CI, $5103-$10,507; P < .001) ($1013 vs -$6422). CONCLUSIONS AND RELEVANCE: In this hospital system, the occurrence of postsurgical complications was associated with a higher per-encounter hospital contribution margin for patients covered by Medicare and private insurance but a lower one for patients covered by Medicaid and who self-paid. Depending on payer mix, many hospitals have the potential for adverse near-term financial consequences for decreasing postsurgical complications.
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Custo Compartilhado de Seguro , Grupos Diagnósticos Relacionados , Administração Financeira de Hospitais , Custos Hospitalares/estatística & dados numéricos , Alta do Paciente/estatística & dados numéricos , Complicações Pós-Operatórias/economia , Idoso , Hospitais Filantrópicos/economia , Humanos , Seguro Saúde/economia , Classificação Internacional de Doenças , Medicaid/economia , Medicare/economia , Pessoa de Meia-Idade , Setor Privado , Reembolso de Incentivo , Estudos Retrospectivos , Estados UnidosRESUMO
The small subunit (SSU) processome is a ribosome biogenesis intermediate that assembles from its subcomplexes onto the pre-18S rRNA with yet unknown order and structure. Here, we investigate the architecture of the UtpB subcomplex of the SSU processome, focusing on the interaction between the half-a-tetratricopeptide repeat (HAT) domain of Utp6 and a specific peptide in Utp21. We present a comprehensive map of the interactions within the UtpB subcomplex and further show that the N-terminal domain of Utp6 interacts with Utp18 while the HAT domain interacts with Utp21. Using a panel of point and deletion mutants of Utp6, we show that an intact HAT domain is essential for efficient pre-rRNA processing and cell growth. Further investigation of the Utp6-Utp21 interaction using both genetic and biophysical methods shows that the HAT domain binds a specific peptide ligand in Utp21, the first example of a HAT domain peptide ligand, with a dissociation constant of 10 muM.