Geographic access to high capability severe acute respiratory failure centers in the United States

Interhospital Transfer of Patients With Acute Respiratory Failure in the United States: A Scoping Review

OBJECTIVES

Interhospital transfer of patients with acute respiratory failure (ARF) is relevant in the current landscape of critical care delivery. However, current transfer practices for patients with ARF are highly variable, poorly formalized, and lack evidence. We aim to synthesize the existing evidence, identify knowledge gaps, and highlight persisting questions related to interhospital transfer of patients with ARF.

DATA SOURCES

Ovid Medline, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, Embase, CINAHL Plus, and American Psychological Association.

STUDY SELECTION

We included studies that evaluated or described hospital transfers of adult (age > 18) patients with ARF between January 2020 and 2024 conducted in the United States. Using predetermined search terms and strategies, a total of 3369 articles were found across all databases. After deduplication, 1748 abstracts were screened by authors with 45 articles that advanced to full-text review. This yielded 16 studies that fit our inclusion criteria.

DATA EXTRACTION

The studies were reviewed in accordance to Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews by three authors.

DATA SYNTHESIS

Included studies were mostly retrospective analyses of heterogeneous patients with various etiologies and severity of ARF. Overall, transferred patients were younger, had high severity of illness, and were more likely to have commercial insurance compared with nontransferred cohorts. There is a paucity of data examining why patients get transferred. Studies that retrospectively evaluated outcomes between transferred and nontransferred cohorts found no differences in mortality, although transferred patients have a longer length of stay. There is limited evidence to suggest that patients transferred early in their course have improved outcomes.

CONCLUSIONS

Our scoping review highlights the sparse evidence and the urgent need for further research into understanding the complexity behind ARF transfers. Future studies should focus on defining best practices to inform clinical decision-making and improve downstream outcomes.

Characteristics of Patients Hospitalized in Rural and Urban ICUs From 2010 to 2019

OBJECTIVES

Rural hospitals are threatened by workforce shortages and financial strain. To optimize regional critical care delivery, it is essential to understand what types of patients receive intensive care in rural and urban hospitals.

DESIGN

A retrospective cohort study.

SETTING AND PATIENTS

All fee-for-service Medicare beneficiaries in the United States who were 65 years old or older hospitalized in an ICU between 2010 and 2019 were included. Rural and urban hospitals were classified according to the 2013 National Center For Health Statistics Urban-Rural Classification Scheme for Counties. Patient comorbidities, primary diagnoses, organ dysfunction, and procedures were measured using the International Classification of Diseases, 9th and 10th revisions diagnosis and procedure codes. Standardized differences were used to compare rural and urban patient admission characteristics.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

There were 12,224,097 ICU admissions between 2010 and 2019, and 1,488,347 admissions (12.2%) were to rural hospitals. The most common diagnoses in rural hospitals were cardiac (30.3%), infectious (24.6%), and respiratory (10.9%). Patients in rural ICUs had similar organ dysfunction compared with urban hospitals (mean organ failures in rural ICUs 0.5, sd 0.8; mean organ failures in urban ICUs 0.6, sd 0.9, absolute standardized mean difference 0.096). Organ dysfunction among rural ICU admissions increased over time (0.4 mean organ failures in 2010 to 0.7 in 2019, p < 0.001).

CONCLUSIONS

Rural hospitals care for an increasingly complex critically ill patient population with similar organ dysfunction as urban hospitals. There is a pressing need to develop policies at federal and regional healthcare system levels to support the continued provision of high-quality ICU care within rural hospitals.

Rural-Urban Differences in Mortality among Mechanically Ventilated Patients in Intensive and Intermediate Care

Rationale: Intermediate care (also termed "step-down" or "moderate care") has been proposed as a lower cost alternative to care for patients who may not clearly benefit from intensive care unit admission. Intermediate care units may be appealing to hospitals in financial crisis, including those in rural areas. Outcomes of patients receiving intermediate care are not widely described. Objectives: To examine relationships among rurality, location of care, and mortality for mechanically ventilated patients. Methods: Medicare beneficiaries aged 65 years and older who received invasive mechanical ventilation between 2010 and 2019 were included. Multivariable logistic regression was used to estimate the association between admission to a rural or an urban hospital and 30-day mortality, with separate analyses for patients in general, intermediate, and intensive care. Models were adjusted for age, sex, area deprivation index, primary diagnosis, severity of illness, year, comorbidities, and hospital volume. Results: There were 2,752,492 hospitalizations for patients receiving mechanical ventilation from 2010 to 2019, and 193,745 patients (7.0%) were in rural hospitals. The proportion of patients in rural intermediate care increased from 4.1% in 2010 to 6.3% in 2019. Patient admissions to urban hospitals remained relatively stable. Patients in rural and urban intensive care units had similar adjusted 30-day mortality, at 46.7% (adjusted absolute risk difference -0.1% [95% confidence interval, -0.7% to 0.6%]; P = 0.88). However, adjusted 30-day mortality for patients in rural intermediate care was significantly higher (36.9%) than for patients in urban intermediate care (31.3%) (adjusted absolute risk difference 5.6% [95% confidence interval, 3.7% to 7.6%]; P < 0.001). Conclusions: Hospitalization in rural intermediate care was associated with increased mortality. There is a need to better understand how intermediate care is used across hospitals and to carefully evaluate the types of patients admitted to intermediate care units.

Regional access to a centralized extracorporeal membrane oxygenation (ECMO) service in Victoria, Australia

Introduction

Victoria, Australia provides a centralised state ECMO service, supported by ambulance retrieval. Equity of access to this service has not been previously described.

Objective

Describe the characteristics of ECMO recipients and quantify geographical and socioeconomic influence on access.

Design

Retrospective observational study with spatial mapping.

Participants and setting

Adult (≥18 years) ECMO recipients from July 2016-June 2022. Data from administrative Victorian Admissions Episodes Database analysed in conjunction with Australian Urban Research Infrastructure Network population data and choropleth mapping. Presumed ECMO modes were inferred from cardiopulmonary bypass and pre-hospital cardiac arrest codes. Spatial autoregressive models including Moran's test used for spatial lag testing.

Outcomes

Demographics and outcomes of ECMO recipients; ECMO incidence by patient residence (Statistical-Area Level 2, SA-2) and Index of Relative Socioeconomic Advantage and Disadvantage (IRSAD); and ECMO utilisation adjusted for patient factors and linear distance from the central ECMO referral site.

Results

631 adults received ECMO over 6 years, after exclusion of paediatric (n = 242), duplicate (n = 135), and interstate or incomplete (n = 72) records. Mean age was 51.8 years, and 68.8 % were male. Overall ECMO incidence was 3.00 ± 3.95 per 105 population. 135 (21.4 %) were presumed VA-ECMO, 59 (9.3 %) presumed ECPR, and 437 (69.3 %) presumed VV-ECMO. Spatial lag was non-significant after adjusting for patient characteristics. Distance from the central referral site (dy/dx = 0.19, 95% CI -0.41-0.04, p = 0.105) and IRSAD score (dy/dx = 0.17, 95% CI -0.19-0.53, p = 0.359) did not predict ECMO utilisation.

Conclusion

Victorian ECMO incidence rates were low. We did not find evidence of inequity of access to ECMO irrespective of regional area or socioeconomic status.

"Death as the One Great Certainty": ethical implications of children with irreversible cardiorespiratory failure and dependence on extracorporeal membrane oxygenation

Introduction

Advances in medical technology have led to both clinical and philosophical challenges in defining death. Highly publicized cases have occurred when families or communities challenge a determination of death by the irreversible cessation of neurologic function (brain death). Parallels can be drawn in cases where an irreversible cessation of cardiopulmonary function exists, in which cases patients are supported by extracorporeal cardiopulmonary support, such as extracorporeal membrane oxygenation (ECMO).

Analysis

Two cases and an ethical analysis are presented which compare and contrast contested neurologic determinations of death and refusal to accept the irreversibility of an imminent death by cardiopulmonary standards. Ambiguities in the Uniform Determination of Death Act are highlighted, as it can be clear, when supported by ECMO, that a patient could have suffered the irreversible cessation of cardiopulmonary function yet still be alive (e.g., responsive and interactive). Parallel challenges with communication with families around the limits of medical technology are discussed.

Discussion

Cases that lead to conflict around the removal of technology considered not clinically beneficial are likely to increase. Reframing our goals when death is inevitable is important for both families and the medical team. Building relationships and trust between all parties will help families and teams navigate these situations. All parties may require support for moral distress. Suggested approaches are discussed.

Racial and Ethnic Disparities in Veno-Venous Extracorporeal Membrane Oxygenation Mortality for Patients With Severe COVID-19

Racial/ethnic disparities in mortality were observed during the coronavirus disease-2019 pandemic, but investigations examining the association between race/ethnicity and mortality during extracorporeal membrane oxygenation (ECMO) are limited. We performed a retrospective observational cohort study using the 2020 national inpatient sample. Multivariable logistic regression was used to estimate the odds of mortality in patients of difference race/ethnicity while controlling for confounders. There was a significant association between race/ethnicity and in-hospital mortality ( p < 0.001). Hispanic patients had significantly higher in-hospital mortality compared with White patients (odds ratio [OR] = 1.39, 95% confidence interval [CI] = 1.16-1.67, p < 0.001). Black patients and patients of other races did not have significantly higher in-hospital mortality compared with White patients (OR = 0.82, 95% CI = 0.66-1.02, p = 0.07 and OR = 1.20, 95% CI = 0.92-1.57, p = 0.18). Other variables that had a significant association with mortality included age, insurance type, Charlson comorbidity index, all patient-refined severity of illness, and receipt of care in a low-volume ECMO center (all p < 0.001). Further studies are needed to understand causes of disparities in ECMO mortality.

Social Drivers of Health and Pediatric Extracorporeal Membrane Oxygenation Outcomes

BACKGROUND

Relationships between social drivers of health (SDoH) and pediatric health outcomes are highly complex with substantial inconsistencies in studies examining SDoH and extracorporeal membrane oxygenation (ECMO) outcomes. To add to this literature with emerging novel SDoH measures, and to address calls for institutional accountability, we examined associations between SDoH and pediatric ECMO outcomes.

METHODS

This single-center retrospective cohort study included children (<18 years) supported on ECMO (2012-2021). SDoH included Child Opportunity Index (COI), race, ethnicity, payer, interpreter requirement, urbanicity, and travel-time to hospital. COI is a multidimensional estimation of SDoH incorporating traditional (eg, income) and novel (eg, healthy food access) neighborhood attributes ([range 0-100] higher indicates healthier child development). Outcomes included in-hospital mortality, ECMO run duration, and length of stay (LOS).

RESULTS

540 children on ECMO (96%) had a calculable COI. In-hospital mortality was 44% with median run duration of 125 hours and ICU LOS 29 days. Overall, 334 (62%) had cardiac disease, 92 (17%) neonatal respiratory failure, 93 (17%) pediatric respiratory failure, and 21 (4%) sepsis. Median COI was 64 (interquartile range 32-81), 323 (60%) had public insurance, 174 (34%) were from underrepresented racial groups, 57 (11%) required interpreters, 270 (54%) had urban residence, and median travel-time was 89 minutes. SDoH including COI were not statistically associated with outcomes in univariate or multivariate analysis.

CONCLUSIONS

We observed no significant difference in pediatric ECMO outcomes according to SDoH. Further research is warranted to better understand drivers of inequitable health outcomes in children, and potential protective mechanisms.

Comparing strategies for prehospital transport to specialty care after cardiac arrest

Outcomes are better when patients resuscitated from out-of-hospital cardiac arrest (OHCA) are treated at specialty centers. The best strategy to transport patients from the scene of resuscitation to specialty care is unknown.

METHODS

We performed a retrospective cohort study. We identified patients treated at a single specialty center after OHCA from 2010 to 2021 and used OHCA geolocations to develop a catchment area using a convex hull. Within this area, we identified short term acute care hospitals, OHCA receiving centers, adult population by census block group, and helicopter landing zones. We determined population-level times to specialty care via: (1) direct ground transport; (2) transport to the nearest hospital followed by air interfacility transfer; and (3) ground transport to air ambulance. We used an instrumental variable (IV) adjusted probit regression to estimate the causal effect of transport strategy on functionally favorable survival to hospital discharge.

RESULTS

Direct transport to specialty care by ground to air ambulance had the shortest population-level times from OHCA to specialty care (median 56 [IQR 47-66] minutes). There were 1,861 patients included in IV regression of whom 395 (21%) had functionally favorable survival. Most (n = 1,221, 66%) were transported to the nearest hospital by ground EMS then to specialty care by air. Patient outcomes did not differ across transport strategies in our IV analysis.

DISCUSSION

We did not find strong evidence in favor of a particular strategy for transport to specialty care after OHCA. Population level time to specialty care was shortest with ground ambulance transport to the nearest helicopter landing zone.

Health Disparities in Extracorporeal Membrane Oxygenation Utilization and Outcomes: A Scoping Review and Methodologic Critique of the Literature

OBJECTIVES

To map the scope, methodological rigor, quality, and direction of associations between social determinants of health (SDoH) and extracorporeal membrane oxygenation (ECMO) utilization or outcomes.

DATA SOURCES

PubMed, Web of Science, Embase, and Cochrane Library databases were systematically searched for citations from January 2000 to January 2023, examining socioeconomic status (SES), race, ethnicity, hospital and ECMO program characteristics, transport, and geographic location (context) with utilization and outcomes (concept) in ECMO patients (population).

STUDY SELECTION

Methodology followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses scoping review extension. Two reviewers independently evaluated abstracts and full text of identified publications. Exclusion criteria included non-English, unavailable, less than 40 patients, and periprocedural or mixed mechanical support.

DATA EXTRACTION

Content analysis used a standardized data extraction tool and inductive thematic analysis for author-proposed mediators of disparities. Risk of bias was assessed using the Quality in Prognosis Studies tool.

DATA SYNTHESIS

Of 8,214 citations screened, 219 studies were identified. Primary analysis focuses on 148 (68%) including race/ethnicity/SES/payer variables including investigation of ECMO outcomes 114 (77%) and utilization 43 (29%). SDoH were the primary predictor in 15 (10%). Overall quality and methodologic rigor was poor with advanced statistics in 7%. Direction of associations between ECMO outcomes or utilization according to race, ethnicity, SES, or payer varied. In 38% adverse outcomes or lower use was reported in underrepresented, under-resourced or diverse populations, while improved outcomes or greater use were observed in these populations in 7%, and 55% had no statistically significant result. Only 26 studies (18%) discussed mechanistic drivers of disparities, primarily focusing on individual- and hospital-level rather than systemic/structural factors.

CONCLUSIONS

Associations between ECMO utilization and outcomes with SDoH are inconsistent, complicated by population heterogeneity and analytic shortcomings with limited consideration of systemic contributors. Findings and research gaps have implications for measuring, analyzing, and interpreting SDoH in ECMO research and healthcare.

The Impact of Obesity on Early Complications Following Tracheostomy: An Evaluation of a Nationwide Registry

INTRODUCTION

The obesity epidemic is an important public health problem in the United States. Previous studies have revealed the association between obesity and various surgical complications. Tracheostomy which is an important lifesaving procedure may prove technically challenging in an obese patient. This study sought to evaluate the association between obesity and early complications following standard tracheostomy using a national registry.

METHODS

Adult patients who underwent tracheostomy from 2007 to 2017 were analyzed using the Nationwide Inpatient Sample (NIS). The population was stratified into obese and non-obese groups. Early complications following standard tracheostomy were identified and compared between the two groups. Multivariable logistic regression analyses were performed to assess the association between obesity and early complications following tracheostomy.

RESULTS

Data pertaining to 205 032 adult patients were evaluated. Obese patients accounted for 12.1% (n = 21 816) of the entire cohort. The most common complication in the cohort was perioperative bleeding (4316 [2.1%]). A total of 1382 (0.67%), 949 (0.46%), and 134 (0.07%) patients developed pneumothorax/pneumomediastinum, stoma/surgical site infection, and tracheal injury following standard tracheostomy, respectively. There was no difference in the odds of tracheal injury, perioperative bleeding, and pneumomediastinum/pneumothorax following standard tracheostomy in the obese and non-obese group in multivariable analysis. However, obesity was associated with 60% increased odds of developing stoma/surgical site infection following standard tracheostomy (OR 1.60 [1.33-1.92], P < 0.01).

CONCLUSION

Obesity is associated with an increased risk of developing stoma/surgical site infection following standard tracheostomy. This adds to the growing need for measures to help curb the obesity epidemic in a bid to improve surgical outcomes.

Selection criteria and triage in extracorporeal membrane oxygenation during coronavirus disease 2019

PURPOSE OF REVIEW

Coronavirus disease 2019 (COVID-19) pandemic changed the way we had to approach hospital- and intensive care unit (ICU)-related resource management, especially for demanding techniques required for advanced support, including extracorporeal membrane oxygenation (ECMO).

RECENT FINDINGS

Availability of ICU beds and ECMO machines widely varies around the world. In critical conditions, such a global pandemic, the establishment of contingency capacity tiers might help in defining to which conditions and subjects ECMO can be offered. A frequent reassessment of the resource saturation, possibly integrated within a regional healthcare coordination system, may be of help to triage the patients who most likely will benefit from advanced techniques, especially when capacities are limited.

SUMMARY

Indications to ECMO during the pandemic should be fluid and may be adjusted over time. Candidacy of patients should follow the same prepandemic rules, taking into account the acute disease, the burden of any eventual comorbidity and the chances of a good quality of life after recovery; but the current capacity of healthcare system should also be considered, and frequently reassessed, possibly within a wide hub-and-spoke healthcare system.

VIDEO ABSTRACT

http://links.lww.com/COCC/A43.

Efficacy of a single-day task trainer-based extracorporeal membrane oxygenation training course

Background

Extracorporeal membrane oxygenation (ECMO) is an advanced medical technology used to treat respiratory and heart failure. The coronavirus pandemic has resulted in significantly more ECMO patients worldwide. However, the number of hospitals with ECMO capabilities and ECMO-trained staff are limited. Training of personnel in ECMO could supplement this demand.

Objective

To evaluate our previously developed ECMO course using a task trainer-based training, as opposed to an existing live tissue-training model, and determine if such a program was adequate and could be expanded to other facilities.

Methods

Seventeen teams, each consisting of a physician and nurse, underwent a 5 hour accelerated ECMO course in which they watched prerecorded ECMO training lectures, primed circuit, cannulated, initiated ECMO, and corrected common complications. Training success was evaluated via knowledge and confidence assessments and observation of each team attempting to initiate ECMO while troubleshooting complications on a Yorkshire swine.

Results

Seventeen teams successfully completed the course. Sixteen teams (94%, 95% CI = 71%-100%) successfully placed the swine on veno-arterial ECMO. Of those 16 teams, 15 successfully transitioned to veno-arterial-venous ECMO. The knowledge assessments and confidence levels of physicians and nurses increased by 24.3% from pretest (mean of 65.3%, SD 14.4%) to posttest (mean of 89.6%, SD 10.3%), p < 0.0001.

Conclusions

An abbreviated one day lecture and hands-on task trainer-based ECMO course resulted in a high rate of successful skill demonstration and improvement of physicians' and nurses' knowledge assessments and confidence levels, similar to our previous live tissue training program.

Intravascular Gas Exchange: Physiology, Literature Review, and Current Efforts

Acute respiratory failure with inadequate oxygenation and/or ventilation is a common reason for ICU admission in children and adults. Despite the morbidity and mortality associated with acute respiratory failure, few proven treatment options exist beyond invasive ventilation. Attempts to develop intravascular respiratory assist catheters capable of providing clinically important gas exchange have had limited success. Only one device, the IVOX catheter, was tested in human clinical trials before development was halted without FDA approval. Overcoming the technical challenges associated with providing safe and effective gas exchange within the confines of the intravascular space remains a daunting task for physicians and engineers. It requires a detailed understanding of the fundamentals of gas transport and respiratory physiology to optimize the design for a successful device. This article reviews the potential benefits of such respiratory assist catheters, considerations for device design, previous attempts at intravascular gas exchange, and the motivation for continued development efforts.

Transport accessibility and social demand: A case study of the Tibetan Plateau

The equity of transport accessibility is a prerequisite for sustainable development targets, especially in the ecologically fragile area of the Tibetan Plateau (also known as the Qinghai-Tibet Plateau). The relationship between transportation supply and social demand has become a key element of socioeconomic development and environmental protection in agricultural and pastoral areas. Based on data from transportation networks, permanent populations and the economy, this study uses a network analysis model, the coefficient of variation and the Gini coefficient to construct an index of social demand in townships and analyse the equity of transport accessibility on the Tibetan Plateau between 1980 and 2017; the principle of geographic distribution and the spatial relationship between transport accessibility and social demand at the township scale are also discussed. This study finds the following: the development of transportation has improved accessibility on the Tibetan Plateau, creating a highly accessible region with important cities as the nodes and major traffic arteries as the axes; both the coefficient of variation of transport accessibility and the Gini coefficient have increased slightly; and the equity of transport accessibility among townships on the Tibetan Plateau has exhibited a downward trend. Further, the social demand index is doubling every ten years, the spatial distribution has regional characteristics, and a decrease in permanent populations is the main reason for declining social demand index scores among townships. Townships with the lowest and highest social demand index scores for transportation development enjoy greater transportation benefits; there is a significant spatial relationship between social demand and location conditions (potential accessibility); the aggregation of social demand and accessibility types follows specific geographical distribution principles; and the Mangya-Gongshan Line delineates the distribution characteristics of township clusters with low social demand and low accessibility.

A comparison of methods for measuring spatial access to health care

OBJECTIVE

To compare measures of spatial access to care commonly used by policy makers and researchers with the more comprehensive enhanced two-step floating catchment area (E2SFCA) method.

STUDY SETTING

Fourteen southwestern Pennsylvania counties.

STUDY DESIGN

We estimated spatial access to buprenorphine-waivered prescribers using three commonly used measures-Euclidean travel distance to the closest prescriber, travel time to the closest provider, and provider-to-population ratios-and the E2SFCA. Unlike other measures, the E2SFCA captures provider capacity, potential patient volume, and travel time to prescribers.

DATA COLLECTION/EXTRACTION METHODS

We measured provider capacity as the number of buprenorphine prescribers listed at a given address in the Drug Enforcement Agency's 2020 Controlled Substances Act Registrants Database, and we measured potential patient volume as the number of nonelderly adults in a given census tract as reported by the 2018 American Community Survey. We estimated travel times between potential patients and prescribers with Bing Maps and Mapbox application programming interfaces. We then calculated each spatial access measure using the R programming language. We used each measure of spatial access to identify census tracts in the lowest quintile of spatial access to prescribers.

PRINCIPAL FINDINGS

The Euclidean distance, travel time, and provider-to-population ratio measures identified 48.3%, 47.2%, and 69.9% of the census tracts that the E2SFCA measure identified as being in the lowest quintile of spatial access to care, meaning that these measures misclassify 30%-52% of study area census tracts as having sufficient spatial access to buprenorphine prescribers.

CONCLUSIONS

Measures of spatial access commonly used by policy makers do not sufficiently accurately identify geographic areas with relatively low access to prescribers of buprenorphine. Using the E2SFCA in addition to the commonly used measures would allow policy makers to precisely target interventions to increase spatial access to opioid use disorder treatment and other types of health care services.

The Southern California Extracorporeal Membrane Oxygenation Consortium During the Coronavirus Disease 2019 Pandemic

In March 2020, at the onset of the coronavirus disease 2019 (COVID-19) pandemic in the United States, the Southern California Extracorporeal Membrane Oxygenation (ECMO) Consortium was formed. The consortium included physicians and coordinators from the 4 ECMO centers in San Diego County. Guidelines were created to ensure that ECMO was delivered equitably and in a resource effective manner across the county during the pandemic. A biomedical ethicist reviewed the guidelines to ensure ECMO use would provide maximal community benefit of this limited resource. The San Diego County Health and Human Services Agency further incorporated the guidelines into its plans for the allocation of scarce resources. The consortium held weekly video conferences to review countywide ECMO capacity (including census and staffing), share data, and discuss clinical practices and difficult cases. Equipment exchanges between ECMO centers maximized regional capacity. From March 1 to November 30, 2020, consortium participants placed 97 patients on ECMO. No eligible patients were denied ECMO due to lack of resources or capacity. The Southern California ECMO Consortium may serve as a model for other communities seeking to optimize ECMO resources during the current COVID-19 or future pandemics.

Development of a novel intravascular oxygenator catheter: Oxygen mass transfer properties across nonporous hollow fiber membranes

Despite hypoxic respiratory failure representing a large portion of total hospitalizations and healthcare spending worldwide, therapeutic options beyond mechanical ventilation are limited. We demonstrate the technical feasibility of providing oxygen to a bulk medium, such as blood, via diffusion across nonporous hollow fiber membranes (HFMs) using hyperbaric oxygen. The oxygen transfer across Teflon® membranes was characterized at oxygen pressures up to 2 bars in both a stirred tank vessel (CSTR) and a tubular device mimicking intravenous application. Fluxes over 550 ml min^-1  m^-2 were observed in well-mixed systems, and just over 350 ml min^-1  m^-2 in flow through tubular systems. Oxygen flux was proportional to the oxygen partial pressure inside the HFM over the tested range and increased with mixing of the bulk liquid. Some bubbles were observed at the higher pressures (1.9 bar) and when bulk liquid dissolved oxygen concentrations were high. High-frequency ultrasound was applied to detect and count individual bubbles, but no increase from background levels was detected during lower pressure operation. A conceptual model of the oxygen transport was developed and validated. Model parametric sensitivity studies demonstrated that diffusion through the thin fiber walls was a significant resistance to mass transfer, and that promoting convection around the fibers should enable physiologically relevant oxygen supply. This study indicates that a device is within reach that is capable of delivering greater than 10% of a patient's basal oxygen needs in a configuration that readily fits intravascularly.

Development and Evaluation of An Abbreviated Extracorporeal Membrane Oxygenation (ECMO) Course for Nonsurgical Physicians and Nurses

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is a modification of cardiopulmonary bypass that allows prolonged support of patients with severe respiratory or cardiac failure. ECMO indications arse rapidly evolving and there is growing interest in its use for cardiac arrest and cardiogenic shock. However, ECMO training programs are limited. Training of emergency medicine and critical care clinicians could expand the use of this lifesaving intervention. Our objective was to develop and evaluate an abbreviated ECMO course that can be taught to emergency and critical care physicians and nurses.

METHODS

We developed a training model using Yorkshire swine (Sus scrofa), a procedure instruction checklist, a confidence assessment, and a knowledge assessment. Participants were assigned to teams of one emergency medicine or critical care physician and one nurse and completed an abbreviated 8-hour ECMO course. An ECMO specialist trained participants on preparation of the ECMO circuit and oversaw vascular access and ECMO initiation. We used the instruction checklist to evaluate performance. Participants completed confidence and knowledge assessments before and after the course.

RESULTS

Seventeen teams (34 clinicians) completed the abbreviated ECMO course. None had previously completed an ECMO certification course. Immediately following the course, all teams successfully primed and prepared the ECMO circuit. Fifteen teams (88%, 95% confidence interval [CI] = 64% to 99%) successfully initiated ECMO. Participants improved their knowledge (difference 21.2, 95% CI = 16.5 to 25.8) and confidence (difference 40.3, 95% CI = 35.6 to 45.0) scores after completing the course.

CONCLUSIONS

We developed an accelerated 1-day ECMO course. Clinicians' confidence and knowledge assessments improved and 88% of teams could successfully initiate venoarterial ECMO after the course.

Trends in Extracorporeal Membrane Oxygenation Growth in the United States, 2011-2014

The use of extracorporeal membrane oxygenation (ECMO) has grown rapidly in recent years. We sought to describe the rate of ECMO use in the United States, regional variation in ECMO use, the hospitals performing ECMO, and the primary payers for ECMO patients. Detailed data were obtained using the Healthcare Cost and Utilization Project (HCUPnet) summaries of State Inpatient Databases from 34 participating states for the years 2011-2014. The ECMO rates over time were modeled, overall and within subcategories of age group, bed size, hospital ownership, teaching status, and payer type. During the study period, the overall rate of ECMO use increased from 1.06 (1.01, 1.12) to 1.77 (1.72, 1.82) cases per 100,000 persons per year (p = 0.005). The rate of ECMO use varied significantly by region. Most ECMO patients are cared for at large hospitals, and at private, not-for-profit hospitals with teaching designation. The most common payer was private insurance; a minority of patient were uninsured. The use of ECMO increased significantly during the study period, but regional variation in the rate of ECMO use suggests that this technology is not being uniformly applied. Further research is warranted to determine why differences in ECMO use persist and what impact they have on patient outcomes.

Use of extracorporeal membrane oxygenation in obstetric patients: a retrospective cohort study

PURPOSE

There is little information on the use of extracorporeal membrane oxygenation (ECMO) in pregnant women. Our objectives are to estimate the use of ECMO in pregnant patients, identify clinical conditions associated with ECMO use, and assess survival rates by the associated condition.

METHODS

Using the Healthcare Cost and Utilization Project-Nationwide Inpatient Sample, we carried out a retrospective cohort study of all delivery admissions in the United States from January 1, 1999, to October 1, 2015. Within the cohort, women who received ECMO therapy were identified using ICD-9 codes and then survival rates among these women were calculated.

RESULTS

There were 83 women who underwent ECMO therapy in our cohort of 15,335,205 births, for an overall ECMO use rate of 0.54/100,000 pregnancies. The incidence of ECMO use increased from 0.23/100,000 in 1999 to 2.57/100,000 in 2015. Patients on ECMO were more likely to be older, have a lower income, and have pre-existing medical conditions when compared with the patients not on ECMO. The overall survival rate for the ECMO group was 62.7%. The most common reason for ECMO use was acute respiratory failure. Etiologies associated with the highest survival in those on ECMO were pneumonia and venous thromboembolism, which were found to have survival rates of 75.0% and 81.0%, respectively.

CONCLUSION

The incidence of ECMO use in the obstetric population increased over the last decade and a half. Although it carries a limited survival rate within this population, it has proven life-saving for many suffering from complications of pregnancy and delivery.

Patterns in Geographic Access to Health Care Facilities Across Neighborhoods in the United States Based on Data From the National Establishment Time-Series Between 2000 and 2014

IMPORTANCE

The association between proximity to health care facilities and improved disease management and population health has been documented, but little is known about small-area health care environments and how the presence of health care facilities has changed over time during recent health system and policy change.

OBJECTIVE

To examine geographic access to health care facilities across neighborhoods in the United States over a 15-year period.

DESIGN, SETTING, AND PARTICIPANTS

Using longitudinal business data from the National Establishment Time-Series, this cross-sectional study examined the presence of and change in ambulatory care facilities and pharmacies and drugstores in census tracts (CTs) throughout the continental United States between 2000 and 2014. Between January and April 2019, multinomial logistic regression was used to estimate associations between health care facility presence and neighborhood sociodemographic characteristics over time.

MAIN OUTCOMES AND MEASURES

Change in health care facility presence was measured as never present, lost, gained, or always present between 2000 and 2014. Neighborhood sociodemographic characteristics (ie, CTs) and their change over time were measured from US Census reports (2000 and 2010) and the American Community Survey (2008-2012).

RESULTS

Among 72 246 included CTs, the percentage of non-US-born residents, residents 75 years or older, poverty status, and population density increased, and 8.1% of CTs showed a change in the racial/ethnic composition of an area from predominantly non-Hispanic (NH) white to other racial/ethnic composition categories between 2000 and 2010. The presence of ambulatory care facilities increased from a mean (SD) of 7.7 (15.9) per CT in 2000 to 13.0 (22.9) per CT in 2014, and the presence of pharmacies and drugstores increased from a mean (SD) of 0.6 (1.0) per CT in 2000 to 0.9 (1.4) per CT in 2014. Census tracts with predominantly NH black individuals (adjusted odds ratio [aOR], 2.37; 95% CI, 2.03-2.77), Hispanic/Latino individuals (aOR 1.30; 95% CI, 1.00-1.69), and racially/ethnically mixed individuals (aOR, 1.53; 95% CI, 1.33-1.77) in 2000 had higher odds of losing health care facilities between 2000 and 2014 compared with CTs with predominantly NH white individuals, after controlling for other neighborhood characteristics. Census tracts of geographic areas with higher levels of poverty in 2000 also had higher odds of losing health care facilities between 2000 and 2014 (aOR, 1.12; 95% CI, 1.05-1.19).

CONCLUSIONS AND RELEVANCE

Differential change was found in the presence of health care facilities across neighborhoods over time, indicating the need to monitor and address the spatial distribution of health care resources within the context of population health disparities.

Regional Planning for Extracorporeal Membrane Oxygenation Allocation During Coronavirus Disease 2019

Health systems confronting the coronavirus disease 2019 (COVID-19) pandemic must plan for surges in ICU demand and equitably distribute resources to maximize benefit for critically ill patients and the public during periods of resource scarcity. For example, morbidity and mortality could be mitigated by a proactive regional plan for the triage of mechanical ventilators. Extracorporeal membrane oxygenation (ECMO), a resource-intensive and potentially life-saving modality in severe respiratory failure, has generally not been included in proactive disaster preparedness until recently. This paper explores underlying assumptions and triage principles that could guide the integration of ECMO resources into existing disaster planning. Drawing from a collaborative framework developed by one US metropolitan area with multiple adult and pediatric extracorporeal life support centers, this paper aims to inform decision-making around ECMO use during a pandemic such as COVID-19. It also addresses the ethical and practical aspects of not continuing to offer ECMO during a disaster.

Changes in Oxygen Saturation and Mean Arterial Pressure With Inhaled Epoprostenol in Transport

OBJECTIVE

Patients with hypoxemic respiratory failure have traditionally been considered one of the riskiest patient populations to transport, given the potential for desaturation with movement. We performed a retrospective cohort study to analyze our experience using inhaled epoprostenol in transport, with a primary objective of assessing change in the oxygen saturation throughout the transport.

METHODS

The transport records of patients with severe hypoxemic respiratory failure or right heart failure, transported on inhaled epoprostenol, were reviewed. The primary outcome was the change in SpO₂ from the start of the inhaled epoprostenol transport to the time of handover of care at the receiving institution. The secondary outcome was the change in the mean arterial pressure (MAP).

RESULTS

Comparing the initial SpO₂ to the final, there was no significant difference in oxygenation between time 0 and the transfer of care at the receiving hospital at 91% versus 93% (interquartile range [IQR] 86.0-93.5 vs 87.5-96.0, P = .49). Comparing the SpO₂ for those who had inhaled epoprostenol started by the transport team showed a larger change at 86% compared to 93% (IQR: 83.0-91.0 vs 86.5-94.5, P = .04). There was no change in the median MAP from time 0 to the end of the transport (77 vs 75 mm Hg, IQR, 67.5-84.8 vs 68.5-85.8, P = .70).

CONCLUSIONS

In this study, patients with severe cardiopulmonary compromise transported on inhaled epoprostenol had no significant change in their median oxygen saturations, with the overall population increasing from 91% to 93%. When inhaled epoprostenol was initiated by the transport team, the improvement was clinically and statistically significant with an increase in SpO₂ from 86% to 93%, with a final oxygen saturation comparable to those who were on the medication at the time of the team's arrival.

Access to extracorporeal life support as a quality metric: Lessons from trauma

BACKGROUND

Access to centers with extracorporeal membrane oxygenation (ECMO) capabilities varies by region and may affect overall outcomes. We assessed the outcomes of trauma patients requiring ECMO support and compared the overall survival of all patients with trauma at facilities with and without ECMO capabilities.

METHODS

A retrospective review of the National Trauma Data Bank was performed to identify all trauma patients receiving care at ECMO and non-ECMO centers. Baseline patient characteristics and outcomes were analyzed. Adjusted odds ratio (OR) was used to compare survival at ECMO and non-ECMO facilities.

RESULTS

Between 2007 and 2015, a total of 5 781 123 patients with trauma were identified with 1 983 986 (34%) admitted to an ECMO facility and 3 797 137 (66%) admitted to a non-ECMO facility. A total of 522 (0.03%) patients required ECMO. Both the number of patients with trauma requiring ECMO support and the number of trauma facilities utilizing ECMO increased over the 9-year-study period (4.9 to 13.8 patients per 100 000 admissions, and 18 to 77 centers, respectively). The mortality for ECMO patients was 40.5%. Patients with trauma admitted to ECMO facilities had more severe injuries (injury severity score: 9.0 vs 8.0; P < .001). The overall mortality was 3.3%. The adjusted OR for mortality associated with admission to an ECMO facility vs a non-ECMO facility was 0.96 (95% confidence interval: 0.95-0.97; adjusted P < .001).

CONCLUSIONS

The use of ECMO for patients with trauma is expanding. Our study demonstrates a survival benefit associated with admission to a facility with ECMO capabilities. Thus, access to ECMO is a potential quality metric for trauma centers.

Inhaled Epoprostenol to Facilitate Safe Transport in Legionnaires' Disease

Hypoxemic patients often desaturate further with movement and transport. While inhaled epoprostenol does not improve mortality, improving oxygenation allows for transport of severely hypoxemic patients to tertiary care centers with a related improvement in mortality rates. Extracorporeal membrane oxygenation (ECMO) use is increasing in frequency for patients with refractory hypoxemia, and with increasing regionalization of care, safe transport of hypoxemic patients only becomes more important. In this series, four cases are presented of young patients with severe hypoxemic respiratory failure from Legionnaires' disease transported on inhaled epoprostenol to ECMO centers for consideration of cannulation. With continued climate changes, Legionella and other pathogens are likely to be a continued threat. As such, optimizing oxygenation to allow for transport should continue to be a priority for critical care transport (CCT) services.

Geographic Access to International Board-Certified Lactation Consultants in Pennsylvania

BACKGROUND:

Availability of professional lactation support has been associated with increased breastfeeding rates; however, data about access to international board-certified lactation consultants are limited.

RESEARCH AIMS:

The aims were (a) to assess geographic access to international board-certified lactation consultants in Pennsylvania, (b) to compare access in rural/urban counties, and (c) to compare access by county-level breastfeeding initiation rates.

METHODS:

Using geographic information systems methodology and a cross-sectional observational design, we calculated the proportion of young children living within 15, 30, and 60 miles of international board-certified lactation consultants in Pennsylvania. We calculated these proportions for all children in Pennsylvania, for children in urban and rural counties, and for children in counties with low, medium, and high breastfeeding initiation rates. Comparisons were done to answer the research aims.

RESULTS:

Over 90% of young children live within 30 miles of an international board-certified lactation consultant. Compared to children in urban counties, fewer children in rural counties live within 15 and 30 miles of these providers. In counties with high breastfeeding initiation rates, a larger percentage of children live within 15 miles of an international board-certified lactation consultant than in counties with low breastfeeding initiation rates.

CONCLUSION:

While most Pennsylvania children live in proximity of an international board-certified lactation consultant, this was true for a lower percentage of children in rural counties and in counties with lower breastfeeding rates.

When the momentum has gone: what will be the role of extracorporeal lung support in the future?

PURPOSE OF REVIEW

There has been expanding interest in and use of extracorporeal support in respiratory failure concurrent with technological advances and predominantly observational data demonstrating improved outcomes. However, until there is more available data from rigorous, high-quality randomized studies, the future of extracorporeal support remains uncertain.

RECENT FINDINGS

Outcomes for patients supported with extracorporeal devices continue to show favorable trends. There are several large randomized controlled trials that are in various stages of planning or completion for extracorporeal membrane oxygenation (ECMO) and extracorporeal carbon dioxide removal (ECCO2R) in the acute respiratory distress syndrome (ARDS) and chronic obstructive pulmonary disease (COPD), which may help clarify the role of this technology for these disease processes, and which stand to have a significant impact on a large proportion of patients with acute respiratory failure. Novel applications of extracorporeal lung support include optimization of donor organ quality through ex-vivo perfusion and extracorporeal cross-circulation, allowing for multimodal therapeutic interventions.

SUMMARY

Despite the ongoing rise in ECMO use for acute respiratory failure, its true value will not be known until more information is gleaned from prospective randomized controlled trials. Additionally, there are modalities beyond the current considerations for extracorporeal support that have the potential to revolutionize respiratory failure, particularly in the realm of chronic lung disease and lung transplantation.

Transportation characteristics associated with non-arrivals to paediatric clinic appointments: a retrospective analysis of 51 580 scheduled visits

BACKGROUND

Prior work has not studied the effects of transportation accessibility and patient factors on clinic non-arrival.

OBJECTIVES

Our objectives were: (1) to evaluate transportation characteristics and patient factors associated with clinic non-arrival, (2) to evaluate the comparability of bus and car drive time estimates, and (3) to evaluate the combined effects of transportation accessibility and income on scheduled appointment non-arrival.

METHODS

We queried electronic administrative records at an urban general pediatrics clinic. We compared patient and transportation characteristics between arrivals and non-arrivals for scheduled appointments using multivariable modeling.

RESULTS

There were 15 346 (29.8%) clinic non-arrivals. In separate car and bus multivariable models that controlled for patient and transit characteristics, we identified significant interactions between income and drive time, and clinic non-arrival. Patients in the lowest quartile of income who were also in the longest quartile of travel time by bus had an increased OR of clinic non-arrival compared with patients in the lowest quartile of income and shortest quartile of travel time by bus (1.55; P<0.01). Similarly, patients in the lowest quartile of income who were also in the longest quartile of travel time by car had an increased OR of clinic non-arrival compared with patients in the lowest quartile of income and shortest quartile of travel time by car (1.21, respectively; P<0.01).

CONCLUSIONS

Clinic non-arrival is associated with the interaction of longer travel time and lower income.

Referral Regions for Time-Sensitive Acute Care Conditions in the United States

STUDY OBJECTIVE

Regional, coordinated care for time-sensitive and high-risk medical conditions is a priority in the United States. A necessary precursor to coordinated regional care is regions that are actionable from clinical and policy standpoints. The Dartmouth Atlas of Health Care, the major health care referral construct in the United States, uses regions that cross state and county boundaries, limiting fiscal or political ownership by key governmental stakeholders in positions to create incentive and regulate regional care coordination. Our objective is to develop and evaluate referral regions that define care patterns for patients with acute myocardial infraction, acute stroke, or trauma, yet also preserve essential political boundaries.

METHODS

We developed a novel set of acute care referral regions using Medicare data in the United States from 2011. For acute myocardial infraction, acute stroke, or trauma, we iteratively aggregated counties according to patient home location and treating hospital address, using a spatial algorithm. We evaluated referral political boundary preservation and spatial accuracy for each set of referral regions.

RESULTS

The new set of referral regions, the Pittsburgh Atlas, had 326 distinct regions. These referral regions did not cross any county or state borders, whereas 43.1% and 98.1% of all Dartmouth Atlas hospital referral regions crossed county and state borders. The Pittsburgh Atlas was comparable to the Dartmouth Atlas in measures of spatial accuracy and identified larger at-risk populations for all 3 conditions.

CONCLUSION

A novel and straightforward spatial algorithm generated referral regions that were politically actionable and accountable for time-sensitive medical emergencies.

Access to High Pediatric-Readiness Emergency Care in the United States

OBJECTIVE

To determine the geographic accessibility of emergency departments (EDs) with high pediatric readiness by assessing the percentage of US children living within a 30-minute drive time of an ED with high pediatric readiness, as defined by collaboratively developed published guidelines.

STUDY DESIGN

In this cross-sectional analysis, we examined geographic access to an ED with high pediatric readiness among US children. Pediatric readiness was assessed using the weighted pediatric readiness score (WPRS) of US hospitals based on the 2013 National Pediatric Readiness Project (NPRP) survey. A WPRS of 100 indicates that the ED meets the essential guidelines for pediatric readiness. Using estimated drive time from ZIP code centroids, we determined the proportions of US children living within a 30-minute drive time of an ED with a WPRS of 100 (maximum), 94.3 (90th percentile), and 83.6 (75th percentile).

RESULTS

Although 93.7% of children could travel to any ED within 30 minutes, only 33.7% of children could travel to an ED with a WPRS of 100, 55.3% could travel to an ED with a WPRS at or above the 90th percentile, and 70.2% could travel to an ED with a WPRS at or above the 75th percentile. Among children within a 30-minute drive of an ED with the maximum WPRS, 90.9% lived closer to at least 1 alternative ED with a WPRS below the maximum. Access varied across census divisions, ranging from 14.9% of children in the East South Center to 56.2% in the Mid-Atlantic for EDs scoring a maximum WPRS.

CONCLUSION

A significant proportion of US children do not have timely access to EDs with high pediatric readiness.

Geographical access to critical care services in Scotland

Background

Critical illness requires specialist and timely management. The aim of this study was to create a geographic accessibility profile of the Scottish population to emergency departments and intensive care units.

Methods

This was a descriptive, geographical analysis of population access to 'intermediate' and 'definitive' critical care services in Scotland. Access was defined by the number of people able to reach services within 45 to 60 min, by road and by helicopter. Access was analysed by health board, rurality and as a country using freely available geographically referenced population data.

Results

Ninety-six percent of the population reside within a 45-min drive of the nearest intermediate critical care facility, and 94% of the population live within a 45-min ambulance drive time to the nearest intensive care unit. By helicopter, these figures were 95% and 91%, respectively. Some health boards had no access to definitive critical care services within 45 min via helicopter or road. Very remote small towns and very remote rural areas had poorer access than less remote and rural regions.

Remote cannulation and extracorporeal membrane oxygenation transport is safe in a newly established program

Extracorporeal membrane oxygenation (ECMO) has become an increasingly utilized modality for the support of patients with severe cardiac or pulmonary dysfunction. Unfortunately, the costs and expertise required to maintain a formal ECMO program preclude the vast majority of hospitals from employing such technology routinely. These barriers to implementation of an effective ECMO program highlight the importance of the safe transport of patients in need of extracorporeal support. While many centers with extensive expertise in the management of patients on extracorporeal support have demonstrated their ability to transport those same patients, the ability of new ECMO programs to provide such transportation remains poorly studied. We established an ECMO program at our institution and immediately provided equipment and personnel to transport patients in need of or receiving extracorporeal support to our institution. Overall, we found that 13 out of 28 patients transported to our institution on ECMO or for consideration of ECMO support during the first 15 months of the program survived to hospital discharge. During that period, four incidents associated with patient transport occurred but none were related to ECMO support or adversely affected patient outcome. These observations demonstrate that new ECMO programs can safely and reliably transport patients on or in need of extracorporeal support.

Interhospital transfers of the critically ill: Time spent at referring institutions influences survival

OBJECTIVE

To determine if the length of stay at a referring institution intensive care unit (ICU) before transfer to a tertiary/quaternary care facility is a risk factor for mortality.

DESIGN

We performed a retrospective chart review of patients transferred to our ICU from referring institution ICUs over a 3-year period. Logistical regression analysis was performed to determine which factors were independently associated with increased mortality. The primary outcomes were ICU and hospital mortality.

MAIN RESULTS

A total of 1248 patients were included in our study. Length of stay at the referring institution was an independent risk factor for both ICU and hospital mortality (P<.0001), with increasing lengths of stay correlating with increased mortality. Each additional day at the referring institution was associated with a 1.04 increase in likelihood of ICU mortality (95% confidence interval, 1.02-1.06; P =0.001) and a 1.029 (95% confidence interval, 1.01-1.05; P .005) increase in likelihood of hospital mortality.

CONCLUSIONS

Length of stay at the referring institution before transfer is a risk factor for worse outcomes, with longer stays associated with increased likelihood of mortality. Further studies delineating which factors most affect length of stay at referring institutions, though a difficult task, should be pursued.