Unconventional Volume-Outcome Associations in Adult Extracorporeal Membrane Oxygenation in the United States

Cardiac Extracorporeal Membrane Oxygenation in Community Cardiac Surgery Program: Are the Results Comparable?

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) outcomes in small centers are commonly considered less favorable than in large-volume centers. New ECMO protocols and procedures were established in our regional community hospital system as part of a cardiogenic shock initiative. This retrospective study aims to evaluate the outcomes of veno-arterial extracorporeal membrane oxygenation (VA ECMO) and extracorporeal cardiopulmonary resuscitation (ECPR) in a community hospital system with cardiac surgery capability and assess whether protocol optimization and cannulation standards result in comparable outcomes to larger centers whether the outcomes of this new ECMO program at the community hospital setting were comparable to the United States averages.

METHODS

Our regional system comprises five hospitals with 1500 beds covering southwestern New Jersey, with only one of these hospitals having cardiac surgery and ECMO capability. In May 2021, the new ECMO program was initiated. Patients were screened by a multidisciplinary call, cannulated by our ECMO team, and subsequently treated by the designated team. We reviewed our cardiac ECMO outcomes over two years, from May 2021 to April 2023, in patients who required ECMO due to cardiogenic shock or as a part of extracorporeal cardiopulmonary resuscitation (ECPR).

RESULTS

A total of 60 patients underwent cardiac ECMO, and all were VA ECMO, including 18 (30%) patients who required ECPR for cardiac arrest. The overall survival rate for our cardiac ECMO program turned out to be 48% (29/60), with 50% (22/42) in VA ECMO excluding ECPR and 39% (7/18) in the ECPR group. The hospital survival rate for the VA ECMO and ECPR groups was 36% (15/42) and 28% (5/18), respectively. The ELSO-reported national average for hospital survival is 48% for VA ECMO and 30% for ECPR. Considering these benchmarks, the hospital survival rate of our program did not significantly lag behind the national average.

CONCLUSIONS

With protocol, cannulation standards, and ECMO management optimized, the VA ECMO results of a community hospital system with cardiac surgery capability were not inferior to those of larger centers.

Volume-outcome relationships for extracorporeal membrane oxygenation in acute myocardial infarction

Acute myocardial infarction (MI) is one of the major scenarios of extracorporeal membrane oxygenation (ECMO) use. The utilization of mechanical circulatory support systems including ECMO varies widely at the hospital level, while whether ECMO volume per hospital is associated with outcomes in acute MI is unclear. Using a Japanese nationwide administrative database, a total of 26,913 patients with acute MI undergoing percutaneous coronary intervention from 154 hospitals were included. The relations among PCI volume for acute MI, observed and predicted in-hospital mortality, and observed and predicted rates of ECMO use were evaluated at the hospital level. Of 26,913 patients, 423 (1.6%) were treated with ECMO, and 1561 (5.8%) died during the hospitalization. Median ECMO use per hospital per year was 0.5. An observed rate of ECMO use was linearly correlated with the predicted probability of ECMO use and was not associated with the observed/predicted in-hospital mortality ratio. The observed/predicted mortality ratio was lowest in hospitals with the observed/predicted ECMO use ratio of around one. In conclusion, ECMO was infrequently used in a setting of acute MI at each hospital annually. An observed rate of ECMO use was not associated with observed/predicted in-hospital mortality ratio, while the observed/predicted in-hospital mortality ratio was lowest when ECMO was used as predicted, suggesting that standardized ECMO use may be an institutional quality indicator in acute MI.

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.

A contemporary analysis of the volume-outcome relationship for extracorporeal membrane oxygenation in the United States

BACKGROUND

A paradoxical increase in mortality following extracorporeal membrane oxygenation at high-volume centers has previously been demonstrated. We examined the association between annual hospital volume and outcomes within a contemporary, national cohort of extracorporeal membrane oxygenation patients.

METHODS

All adults requiring extracorporeal membrane oxygenation for postcardiotomy syndrome, cardiogenic shock, respiratory failure, or mixed cardiopulmonary failure were identified in the 2016 to 2019 Nationwide Readmissions Database. Patients undergoing heart and/or lung transplantation were excluded. A multivariable logistic regression with hospital extracorporeal membrane oxygenation volume parametrized as restricted cubic splines was developed to characterize the risk-adjusted association between volume and mortality. The volume corresponding to the maximum of the spline (43 cases/year) was used to categorize centers as low- or high-volume.

RESULTS

An estimated 26,377 patients met the study criteria, and 48.7% were managed at high-volume hospitals. Patients at low- and high-volume hospitals had similar age, sex, and rates of elective admission. Notably, patients at high-volume hospitals less frequently required extracorporeal membrane oxygenation for postcardiotomy syndrome but more commonly for respiratory failure. After risk adjustment, high-volume hospital status was associated with reduced odds of in-hospital mortality, relative to low-volume hospitals (adjusted odds ratio 0.81, 95% confidence interval 0.78-0.97). Interestingly, patients at high-volume hospitals faced a 5.2-day increment in length of stay (95% confidence interval 3.8-6.5) and $23,500 in attributable costs (95% confidence interval 8,300-38,700).

CONCLUSION

The present study found that greater extracorporeal membrane oxygenation volume was associated with decreased mortality but higher resource use. Our findings may help inform policies regarding access to and centralization of extracorporeal membrane oxygenation care in the United States.

Effect of Hospital Volume on Outcome of Extracorporeal Membrane Oxygenation Support - Nationwide Population-Based Cohort Study in Taiwan

BACKGROUND

In modern critical care, extracorporeal membrane oxygenation (ECMO) is crucial in the management of severe respiratory and cardiac failure. Nationwide studies of the relationship between hospital volume and outcomes of ECMO use are unavailable.Methods and Results: Using Taiwan's National Health Insurance Research Database, we identified 11,734 adult patients who received ECMO support in 101 hospitals between January 1, 2001, and December 31, 2017. Outcomes included in-hospital mortality, 1-year mortality, and ECMO-related complications. Cox proportional hazards model, locally estimated scatterplot smoothing, and restricted cubic spline regression were used to analyze the volume-outcome relationship. The overall in-hospital mortality rate was 65.5%, and the 1-year mortality rate was 70.6% in this database. The 101 hospitals were divided into 4 groups based on annual volume. The in-hospital and 1-year mortality rates were significantly lower in the high-volume group (annual volume >40) than in the low-volume group (annual volume <10).

CONCLUSIONS

For critical care, high-volume hospitals have superior short-term and mid-term outcomes. To make the medical system equitable and reasonable, establishing a rapid and efficient nationwide referral system should be considered.

Annual hospital procedural volume and outcome in extracorporeal membrane oxygenation for respiratory failure

BACKGROUND

The hospital mortality of patients suffering from pulmonary failure requiring venovenous extracorporeal membrane oxygenation (V-V ECMO) or extracorporeal carbon dioxide removal (ECCO₂ R) is high. It is unclear whether outcome correlates with a hospital's annual procedural volume.

METHODS

Data on all V-V ECMO and ECCO₂ R cases treated from 2007 to 2019 was retrieved from the German Institute for Medical Documentation and Information. Comorbidities and outcomes were assessed by DRG, OPS, and ICD codes. The study population was divided into 5 groups depending on annual hospital V-V ECMO and ECCO₂ R volumes (<10 cases; 10-19 cases; 20-29 cases; 30-49 cases; ≥50 cases). Primary outcome was hospital mortality.

RESULTS

A total of 25,096 V-V ECMO and 3,607 ECCO₂ R cases were analyzed. V-V ECMO hospitals increased from 89 in 2007 to 214 in 2019. Hospitals handling <10 cases annually increased especially (64 in 2007 to 149 in 2019). V-V ECMO cases rose from 807 in 2007 to 2,597 in 2019. Over 50% were treated in hospitals handling ≥30 cases annually. Hospital mortality was independent of the annual hospital procedural volume (55.3%; 61.3%; 59.8%; 60.2%; 56.3%, respectively, p=0.287). We detected no differences when comparing hospitals handling <30 cases to those with ≥30 annually (p=0.659). The numbers of ECCO₂ R hospitals and cases has dropped since 2011 (287 in 2007 to 48 in 2019). No correlation between annual hospital procedural volume and hospital mortality was identified (p=0.914).

CONCLUSION

The number of hospitals treating patients requiring V-V ECMO and V-V ECMO cases rose from 2007 to 2019, while ECCO₂ R hospitals and their case numbers decreased. We detected no correlation between annual hospital V-V ECMO or ECCO₂ R volume and hospital mortality.

The Implementation and Outcomes of a Nurse-Run Extracorporeal Membrane Oxygenation Program, a Retrospective Single-Center Study

Supplemental Digital Content is available in the text.

Due to a shortage of perfusionists and increasing utilization of extracorporeal membrane oxygenation in the United States, many programs are training nurses as bedside extracorporeal membrane oxygenation specialists (i.e., nurse-run extracorporeal membrane oxygenation). Our objective was to evaluate if a nurse-run extracorporeal membrane oxygenation program has noninferior survival to discharge and complication rates compared with a perfusionist-run extracorporeal membrane oxygenation program. Additionally, to sought to describe increases in extracorporeal membrane oxygenation capacity and the potential for cost savings by implementing a nurse-run extracorporeal membrane oxygenation program.

Low volume ECMO results study

Objectives: To report extracorporeal membrane oxygenation (ECMO) experience at Princess Alexandra and Gold Coast University hospitals and compare mortality with benchmarks. Design: Case series of patients treated with ECMO. Setting: Two adult tertiary Australian intensive care units with low ECMO case volumes. Participants: Patients treated with ECMO, aged > 18 years. Main outcome measures: Patients were categorised into respiratory, cardiac, and extracorporeal cardiopulmonary resuscitation (eCPR) groups. Observed mortality was compared with mortality predicted using individual risk of death predictions from the Survival after Veno-arterial ECMO (SAVE) and Respiratory ECMO Survival Prediction (RESP) scores; mortality predicted when mortality predictions of the SAVE score were modified to be consistent with the validation cohort in the SAVE study (Alfred Hospital); and with mortality predicted when eCPR patients were all assigned a risk of death equal to Extracorporeal Life Support Organization (ELSO) Registry eCPR mortality. Results: Over 10 years, 86 patients were treated with ECMO. Eight deaths were observed in 49 patients with respiratory failure, below the 95% CI (13-24) for the deaths predicted by the RESP score (P < 0.001). Nine deaths were observed in 27 patients with cardiac failure, below the 95% CI (14-23) for the deaths predicted by the SAVE score (P < 0.001), but within the 95% CI (9-17) for the deaths predicted by the SAVE score modified to be consistent with the Alfred Hospital cohort (P > 0.05). Seven deaths were observed in the ten eCPR patients, within the 95% CI (4-10) predicted using the risk of death derived from the ELSO Registry. Conclusions: Mortality in two low volume ECMO centres was not inferior to benchmarks.

Impact of an Extracorporeal Membrane Oxygenation Intensivist-Led Multidisciplinary Team on Venovenous Extracorporeal Membrane Oxygenation Outcomes

Objectives:

Venovenous extracorporeal membrane oxygenation is increasingly being established as a treatment option for severe acute respiratory failure. We sought to evaluate the impact of a dedicated specialist team-based approach on patient outcomes.

Design:

Retrospective cohort study.

Setting:

Single-center medical ICU in an academic tertiary hospital.

Patients:

Adult patients initiated on venovenous extracorporeal membrane oxygenation for severe acute respiratory failure.

Interventions:

Initiation of an extracorporeal membrane oxygenation intensivist-led multidisciplinary team; critical decisions on extracorporeal membrane oxygenation management were jointly made by a dedicated team of extracorporeal membrane oxygenation intensivists, together with the multidisciplinary team.

Measurements and Main Results:

Eighty-one patients (75%) and 27 patients (35%) were initiated on venovenous extracorporeal membrane oxygenation in the preextracorporeal membrane oxygenation intensivist-led multidisciplinary team (before January 2018) and postextracorporeal membrane oxygenation intensivist-led multidisciplinary team period (after January 2018), respectively. Inhospital (14.8% vs 44.4%, p = 0.006) and ICU mortality (11.1% vs 40.7%, p = 0.005) were significantly lower in the postextracorporeal membrane oxygenation intensivist-led multidisciplinary team period. On multivariate analysis correcting for possible confounding factors (ICU severity and extracorporeal membrane oxygenation-specific mortality prediction scores, body mass index, preextracorporeal membrane oxygenation vasopressor support, preextracorporeal membrane oxygenation cardiac arrest, and days on mechanical ventilation before extracorporeal membrane oxygenation initiation), management by an extracorporeal membrane oxygenation intensivist-led multidisciplinary team remained associated with improved hospital survival (odds ratio, 5.06; 95% CI, 1.20–21.28). Patients in the postextracorporeal membrane oxygenation intensivist-led multidisciplinary team period had less nosocomial infections (18.5% vs 46.9%, p = 0.009), a shorter ICU stay (12 days [interquartile range, 6–16 d] vs 15 days [interquartile range, 10–24 d]; p = 0.049), and none suffered an intracranial hemorrhage or nonhemorrhagic stroke.

Conclusions:

An extracorporeal membrane oxygenation intensivist-led multidisciplinary team approach is associated with improved outcomes in patients initiated on venovenous extracorporeal membrane oxygenation for severe acute respiratory failure.

Vascular Complications Increase Hospital Charges and Mortality in Adult Patients on Extracorporeal Membrane Oxygenation in the United States

Patients on extracorporeal membrane oxygenation (ECMO) who suffer vascular complications frequently accrue additional procedures and costs. We sought to evaluate the effect of ECMO-related vascular complications on hospital charges and in-hospital mortality. Adult discharges involving ECMO from 2004 to 2013 in the National Inpatient Sample were examined. There were 12,636 patients in the cohort. Vascular complications, focusing on arterial complications were identified using ICD-9-CM diagnosis and procedure codes. A multivariable survey linear regression model using median hospital charges was used to model the effect of vascular complications on charges. We used multivariable survey logistic regression to evaluate the effect of vascular complications on in-hospital mortality. Of the 12,636 patients examined, 6467 (51.2%) had ECMO-related vascular complications. Median charges in patients with vascular complications were $ 477,363 (interquartile range: 258,660-875,823) and were $ 282,298 (interquartile range: 130,030-578,027) without vascular complications. On multivariable analysis, patients with vascular complications had 24% higher median charges than patients without vascular complications (Ratio: 1.24; 95% confidence interval [CI]: 1.16-1.33; P < 0.0001) and 34% higher odds of experiencing in-hospital mortality than patients without vascular complications (adjusted odds ratio: 1.34; 95% CI:1.08-1.66; P = 0.009). Vascular complications occur in over half of ECMO patients and are associated with an increased risk of high hospital charges and in-hospital mortality. These findings support the need for identification and modification of risk factors for ECMO-related vascular complications. Furthermore, the standardization of protocols using evidence-based measures to mitigate vascular complications may improve overall ECMO outcomes.

Trends in Mortality and Costs of Pediatric Extracorporeal Life Support

BACKGROUND

Extracorporeal life support (ECLS) has been used for >30 years as a life-sustaining therapy in critically ill patients for a variety of indications. In the current study, we aimed to examine trends in use, mortality, length of stay (LOS), and costs for pediatric ECLS hospitalizations.

METHODS

We performed a retrospective cohort study of pediatric patients (between the ages of 28 days and <21 years) on ECLS using the 2008-2015 National Inpatient Sample, the largest all-payer inpatient hospitalization database generated from hospital discharges. Nonparametric and Cochran-Armitage tests for trend were used to study in-hospital mortality, LOS, and hospitalization costs.

RESULTS

Of the estimated 5847 patients identified and included for analysis, ECLS was required for respiratory failure (36.4%), postcardiotomy syndrome (25.9%), mixed cardiopulmonary failure (21.7%), cardiogenic shock (13.1%), and transplanted graft dysfunction (2.9%). The rate of ECLS hospitalizations increased 329%, from 11 to 46 cases per 100 000 pediatric hospitalizations, from 2008 to 2015 (P < .001). Overall mortality decreased from 50.3% to 34.6% (P < .001). Adjusted hospital costs increased significantly ($214 046 ± 11 822 to 324 841 ± 25 621; P = .002) during the study period despite a stable overall hospital LOS (46 ± 6 to 44 ± 4 days; P = .94).

CONCLUSIONS

Use of ECLS in pediatric patients has increased with substantially improved ECLS survival rates. Hospital costs have increased significantly despite a stable LOS in this group. Dissemination of this costly yet life-saving technology warrants ongoing analysis of use trends to identify areas for quality improvement.

Procedural volume and outcomes in patients undergoing VA-ECMO support

Background

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is increasingly used in patients with critical cardiopulmonary failure. To investigate the association between hospital VA-ECMO procedure volume and outcomes in a large, nationwide registry.

Methods

By using administrative data from the German Federal Health Monitoring System, we analyzed all VA-ECMO procedures performed in Germany from 2013 to 2016 regarding the association of procedural volumes with outcomes and complications.

Results

During the study period, 10,207 VA-ECMO procedures were performed; mean age was 61 years, 43.4% had prior CPR, and 71.2% were male patients. Acute coronary syndrome was the primary diagnosis for VA-ECMO implantation (n = 6202, 60.8%). The majority of implantations (n = 5421) were performed at hospitals in the lowest volume category (≤ 50 implantations per year).

There was a significant association between annualized volume of VA-ECMO procedures and 30-day in-hospital mortality for centers with lower vs. higher volume per year. Multivariable logistic regression showed an increased 30-day in-hospital mortality at hospitals with the lowest volume category (adjusted odds ratio 1.13, 95% confidence interval [CI] 1.01–1.27, p = 0.034).

Similarly, higher likelihood for complications was observed at hospitals with lower vs. higher annual VA-ECMO volume (adjusted odds ratio 1.46, 95% CI 1.29–1.66, p = 0.001).

Conclusions

In this analysis of more than 10,000 VA-ECMO procedures for cardiogenic shock, the majority of implantations were performed at hospitals with the lowest annual volume. Thirty-day in-hospital mortality and likelihood for complications were higher at hospitals with the lowest annual VA-ECMO volume.

Contemporary analysis of charges and mortality in the use of extracorporeal membrane oxygenation: A cautionary tale

Objective

The use of extracorporeal membrane oxygenation (ECMO) has increased exponentially. Costs and outcomes, however, vary considerably by indication. We sought to elucidate and quantify these differences.

Methods

Adult patients supported on ECMO between 2008 and 2016 were analyzed using the Nationwide Inpatient Sample. We divided the study period into an early (2008-2013) and late period (2013-2016). The primary outcome was hospital charges, and the secondary outcomes were mortality, length of stay (LOS), and duration of ECMO support. These were stratified by the 5 most common indications: postcardiotomy shock (PCS), cardiogenic shock (CS), severe acute respiratory failure (SARF), heart (HT), and lung transplantation (LT). Both patient and hospital characteristics were assessed. Charges were adjusted for inflation and analyzed using a generalized linear model with gamma distribution. Pairwise comparison with Bonferroni correction was used to evaluate the cost and multivariate logistic regression to assess the risk of mortality.

Results

Data pertaining to 15,829 adult patients were evaluated. Mean age of the entire cohort was 52.8 years, 8895 (56%) were white, and 10,278 (65%) were male. PCS was the predominant indication for ECMO (39%), followed by CS (37%). SARF accounted for 15% and HT and LT accounted for 3.9% and 5.4%, respectively. Mean LOS and duration of ECMO support were 23.4 days and 5.3 days respectively. Mean hospital charges per hospitalization for the entire cohort were USD 731,914 per patient. Charges per patient pertaining to hospitalizations in which ECMO was used in transplant patients were the highest: USD 1,448,931 and USD 1,574,378 (P = .99) for HT and LT, respectively. Charges were lower for the other indications: PCS USD 798,909, CS USD 655,099, and SARF USD 824,852. Overall mortality for the entire cohort was 55%. PCS and CS (53% vs 58%, P = .34) had similar survival, whereas SARF was 45%, LT was 39% and HT 32%. There were no differences in survival in these latter indications (SARF, LT and HT). The cumulative charges (proportion × hospital charges) reveal that PCS and CS (39% and 37%) account for both the majority of charges as well as the greatest mortality. Conversely, SARF and transplantation accounted for the smaller proportion of charges and the lower mortality. Patients undergoing HT had the longest LOS (51.7 days) and duration on ECMO (15.9 days), followed by LT (35.4 and 8.8 days respectively), and patients with SARF (28.6 and 6.6 respectively). LOS and duration of ECMO for those with PCS were 18.7 days and 4.8 days, respectively. Those on ECMO for CS were hospitalized for 19.7 days and spent an average of 3.8 days on ECMO. Mortality decreased, whereas charges increased in the late era.

Conclusions

The use of ECMO is associated with high hospital charges and a wide variation in outcomes. Hospitalizations, in which ECMO is used to support patients with cardiogenic shock (PCS and CS), are individually associated with lower LOS and charges. Cumulatively, however, these account for greater charges and greater mortality. Although mortality may be decreasing, overall charges are increasing with time. These variations may influence reimbursement decisions in value-based healthcare.

Epidemiology and volume-outcome relationship of extracorporeal membrane oxygenation for respiratory failure in Japan: A retrospective observational study using a national administrative database

Aim

To describe the epidemiology of patients on extracorporeal membrane oxygenation (ECMO) and investigate the possible association between outcomes for respiratory ECMO patients and hospital volume of ECMO treatment for any indications.

Methods

Using data from the Diagnosis Procedure Combination database, a nationwide Japanese inpatient database, between 1 July 2010 and 31 March 2018, we identified inpatients aged ≥18 years who underwent ECMO. Institutional case volume was defined as the mean annual number of ECMO cases; eligible patients were categorized into institutional case volume tertile groups. The primary outcome was in-hospital mortality. For ECMO patients with respiratory failure, the association between institutional case volume group and in-hospital mortality rate was analyzed using a multilevel logistic regression model including multiple imputation.

Results

Extracorporeal membrane oxygenation was carried out on 25,384 patients during the study period; of those, 1,227 cases were for respiratory failure. Respiratory cases were categorized into low- (<8 cases/year), medium- (8-16 cases/year), and high-volume groups (≥17 cases/year). The overall in-hospital mortality rate for respiratory ECMO was 62.5% in low-, 54.7% in medium-, and 50.4% in high-volume institutions. With reference to low-volume institutions, the adjusted odds ratios (95% confidence interval) of the medium- and high-volume institutions for in-hospital mortality were 0.72 (0.50-1.04; P = 0.082) and 0.65 (0.45-0.95; P = 0.024), respectively.

Conclusions

The present study showed that accumulating the experience of using ECMO for any indications could positively affect the outcome of ECMO treatment for respiratory failure, which suggests the effectiveness of consolidating ECMO cases in high-volume centers in Japan.

Hospital Variation in the Utilization of Short-Term Nondurable Mechanical Circulatory Support in Myocardial Infarction Complicated by Cardiogenic Shock

BACKGROUND

Limited knowledge exists on inter-hospital variation in the utilization of short-term, nondurable mechanical circulatory support (MCS) for myocardial infarction (MI) complicated by cardiogenic shock (CS).

METHODS AND RESULTS

Hospitalizations for MI with CS in 2014 in a nationally representative all-payer database were included. The proportion of hospitalizations for MI with CS using MCS (MCS ratio) and in-hospital mortality were evaluated. Hospital characteristics and outcomes were compared across quartiles of MCS usage. Of 1813 hospitals evaluated, 1440 (79.4%) performed ≥10 percutaneous coronary interventions annually. Of these, 1064 (73.9%) had at least one code for MCS. Forty-one percent of hospitals did not use MCS. The median (interquartile range) proportion of MCS use among admissions for MI with CS was 33.3% (0.0%-50.0%). High MCS utilizing hospitals were larger ( P<0.001). Eighty-five percent (2808/3301) of MCS use was intra-aortic balloon pump. There was significant variation in receipt of MCS at different hospitals (median odds ratio of receiving MCS at 2 random hospitals: 1.58; 95% CI, 1.45-1.70). Adjusted in-hospital mortality was not different across quartiles of MCS use (Q4 versus Q1; odds ratio, 0.95; 95% CI, 0.77-1.16; P=0.58).

CONCLUSIONS

Wide variation exists in hospital use of MCS for MI with CS, unexplained by patient characteristics. The predominant form of MCS use is intra-aortic balloon pump. Risk-adjusted mortality rates were not different between higher and lower MCS-utilizing hospitals.

Extracorporeal Membrane Oxygenation Use in Cardiogenic Shock: Impact of Age on In-Hospital Mortality, Length of Stay, and Costs

OBJECTIVES

Increasing age is a well-recognized risk factor for in-hospital mortality in patients receiving extracorporeal membrane oxygenation for cardiogenic shock, but the shape of this relationship is unknown. In addition, the impact of age on hospital length of stay, patterns of patient disposition, and costs has been incompletely characterized.

DESIGN

Retrospective analysis of the National Inpatient Sample.

SETTING

U.S. nonfederal hospitals, years 2004-2016.

PATIENTS

Adults with cardiogenic shock treated with extracorporeal membrane oxygenation (3,094; weighted national estimate: 15,415).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The mean age of extracorporeal membrane oxygenation recipients was 54.8 ± 15.4 years (range, 18-90 yr). Crude in-hospital mortality was 57.7%. Median time-to-death was 8 days (interquartile range, 3-17 d). A linear relationship between age and in-hospital mortality was observed with a 14% increase in the adjusted odds of in-hospital mortality for every 10-year increase in age (adjusted odds ratio, 1.14; 95% CI, 1.08-1.21; p < 0.0001). Thirty-four percent of patients were discharged alive at a median time of 30 days (interquartile range, 19-48 d). The median length of stay and total hospitalization costs were 14 days (interquartile range, [5-29 d]) and $134,573 ($71,782-$239,439), respectively, both of which differed significantly by age group (length of stay range from 17 d [18-49 yr] to 9 d [80-90 yr]; p < 0.0001 and cost range $147,548 [18-49 yr] to $105,350 [80-90 yr]; p < 0.0001).

CONCLUSIONS

Age is linearly associated with increasing in-hospital mortality in individuals receiving extracorporeal membrane oxygenation for cardiogenic shock without evidence of a threshold effect. Median time-to-death is approximately 1 week. One third of patients are discharged from the hospital alive, but the median time-to-discharge is 1 month. Median length of stay ranges from 9 to 17 days depending on age. Hospitalization costs exceed $100,000 in all age groups.

Extracorporeal Life Support for Adults With Respiratory Failure and Related Indications: A Review

IMPORTANCE

The substantial growth over the last decade in the use of extracorporeal life support for adults with acute respiratory failure reveals an enthusiasm for the technology not always consistent with the evidence. However, recent high-quality data, primarily in patients with acute respiratory distress syndrome, have made extracorporeal life support more widely accepted in clinical practice.

OBSERVATIONS

Clinical trials of extracorporeal life support for acute respiratory failure in adults in the 1970s and 1990s failed to demonstrate benefit, reducing use of the intervention for decades and relegating it to a small number of centers. Nonetheless, technological improvements in extracorporeal support made it safer to use. Interest in extracorporeal life support increased with the confluence of 2 events in 2009: (1) the publication of a randomized clinical trial of extracorporeal life support for acute respiratory failure and (2) the use of extracorporeal life support in patients with severe acute respiratory distress syndrome during the influenza A(H1N1) pandemic. In 2018, a randomized clinical trial in patients with very severe acute respiratory distress syndrome demonstrated a seemingly large decrease in mortality from 46% to 35%, but this difference was not statistically significant. However, a Bayesian post hoc analysis of this trial and a subsequent meta-analysis together suggested that extracorporeal life support was beneficial for patients with very severe acute respiratory distress syndrome. As the evidence supporting the use of extracorporeal life support increases, its indications are expanding to being a bridge to lung transplantation and the management of patients with pulmonary vascular disease who have right-sided heart failure. Extracorporeal life support is now an acceptable form of organ support in clinical practice.

CONCLUSIONS AND RELEVANCE

The role of extracorporeal life support in the management of adults with acute respiratory failure is being redefined by advances in technology and increasing evidence of its effectiveness. Future developments in the field will result from technological advances, an increased understanding of the physiology and biology of extracorporeal support, and increased knowledge of how it might benefit the treatment of a variety of clinical conditions.

Potential disease burden of patients with substance abuse undergoing major abdominal surgery: A propensity score-matched analysis

BACKGROUND

Over 19 million Americans have a substance abuse disorder. The current study sought to characterize the relationship between substance abuse with in-hospital outcomes following major, elective abdominal surgery.

METHODS

The Nationwide Inpatient Sample was used to identify patients who underwent major abdominal surgery between 2007 to 2014. Patients with preoperative substance abuse, including alcohol, opioids, and non-opioid drugs, were identified. Propensity score matching was used to examine the association of substance abuse with perioperative outcomes.

RESULTS

Among 301,659 patients, 7,925 patients (2.6%) had a history of substance abuse. Pancreatectomy was the surgical procedure with the highest proportion of patients with substance abuse history (n = 844, 4.7%). Compared with patients without a substance abuse history, patients with a substance abuse history were more likely to be younger (median age, 60 years [interquartile range (IQR) 52-69] vs 63 years [IQR 52-72]), male (n = 5,438, 67.5% vs n = 132,961, 54.7%), and be in the lowest income category (n = 2,062, 26% vs n = 64,345, 21.9%) (all P < .001). On propensity score matching, substance abuse was associated with increased odds ratio of experiencing a complication (odds ratio [OR] 1.68, 95% confidence interval [CI] 1.55-1.82), non-home discharge (OR 1.95, 95% CI 1.76-2.16), extended length of stay (OR 1.88, 95% CI 1.76-2.02), and higher expenditure (OR 1.62, 95% CI 1.49-1.77). Stratified by the type of substance abuse, patients with history of alcohol (OR 1.57, 95% CI 1.44-1.71) and drug abuse (OR 1.26, 95% CI 1.14-1.39) were more likely to experience a complication, whereas only history of alcohol abuse was associated with higher odds ratio of in-hospital mortality (OR 1.38, 95% CI 1.07-1.79) (all P < .05).

CONCLUSION

Up to 1 in 50 patients undergoing complex abdominal surgery had a substance abuse history. History of substance abuse was associated with an increased risk of adverse perioperative outcomes and higher healthcare expenditures.

Venovenous extracorporeal membrane oxygenation treatment in a low-volume and geographically isolated cardiothoracic centre

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) treatment is generally offered in large tertiary cardiothoracic referral centres. Here we present the indications and outcome of venovenous-ECMO (VV-ECMO) treatment in a low-volume, geographically isolated single-centre in Iceland, a country of 350 000 inhabitants. Our hypothesis was that patient survival in such a centre can be similar to that at high-volume centres.

METHODS

A retrospective study that included all patients treated with VV-ECMO in Iceland from 1991-2016 (n = 17). Information on demographics, indications and in-hospital survival was collected from patient charts and APACHE II and Murray scores were calculated. Information on long-term survival was collected from a centralized registry.

RESULTS

Seventeen patients were treated with VV-ECMO (nine males, median age 33 years, range 14-74), the indication for 16 patients was severe acute respiratory distress syndrome, most often following pneumonia (n = 6), H1N1-infection (n = 3) or drowning (n = 2). Median APACHE-II and Murray-scores were 20 and 3.5, respectively, and median duration of VV-ECMO treatment was 9 days (range 2-40 days). In total 11 patients (64,7%) survived the treatment, with 10 patients (58,8%) surviving hospital discharge, all of who were still alive at long-term follow-up, with a median follow-up time of 9 years (August 15th, 2017).

CONCLUSION

Venovenous-ECMO service can be provided in a low-volume and geographically isolated centre, like Iceland, with short- and long-term outcomes comparable to larger centres.

Rehospitalization and resource use after inpatient admission for extracorporeal life support in the United States

BACKGROUND

With increasing dissemination and improved survival after extracorporeal life support, also called extracorporeal membrane oxygenation, the decrease in readmissions after hospitalization involving extracorporeal life support is an emerging priority. The present study aimed to identify predictors of early readmission after extracorporeal life support at a national level.

METHODS

This was a retrospective cohort study using the Nationwide Readmissions Database. All patients ≥18 years who underwent extracorporeal life support from 2010 to 2015 were identified. Patients were stratified into the following categories of extracorporeal life support: postcardiotomy, primary cardiogenic shock, cardiopulmonary failure, respiratory failure, transplantation, and miscellaneous. The primary outcome of the study was the rate of 90-day rehospitalization after extracorporeal life support admission. A multivariable logistic regression model was developed to predict the odds of unplanned 90-day readmission. Kaplan-Meier analyses were also performed.

RESULTS

An estimated 18,748 patients received extracorporeal life support with overall mortality of 50.2%. Of the patients who survived hospitalization, 30.2% were discharged to a skilled nursing facility, and 21.1% were readmitted within 90 days after discharge. After adjusting for patient and hospital characteristics, cardiogenic shock was associated with the greatest odds of mortality (adjusted odds ratio 1.6; 95% confidence interval, 1.09-1.46; C-statistic, 0.64). The cohort with respiratory failure had decreased odds of readmission (adjusted odds ratio 0.76; 95% confidence interval, 0.58-0.99). Discharge to skilled nursing facility (adjusted odds ratio 1.64; 95% confidence interval, 1.36-1.97) was independently associated with readmission. Cardiac and respiratory-related readmissions comprised the majority of unplanned 90-day rehospitalizations.

CONCLUSION

In this large analysis of readmissions after extracorporeal life support in adults, 21% of extracorporeal life support survivors were rehospitalized within 90 days of discharge. Disposition to a skilled nursing facility, but not advanced age nor female sex, was associated with readmission.

Volume-Outcome Relationships in Extracorporeal Membrane Oxygenation: Retrospective Analysis of Administrative Data From Pennsylvania, 2007-2015

This article seeks to understand whether a volume-outcome relationship exists in adult extracorporeal membrane oxygenation (ECMO). We examined primary administrative discharge data from the Pennsylvanian Health Care Cost Containment Council for all 2,948 consecutive adults treated with ECMO in Pennsylvania between January 1, 2007, and December 31, 2015. We used a well-fitting backwards stepwise logistic regression to obtain patient-level predicted mortality. Number of cases and risk-adjusted mortality was aggregated by calendar quarter and by hospital. Graphical and correlation analysis was used to understand the volume-outcome relationship, focusing separately on the impact of a hospital's current scale (annual volume of adult ECMO) and a hospital's cumulative experience (total cumulative volume of adult ECMO since starting operations). We found that more than 9 years, there was essentially no reduction in overall risk-adjusted mortality in the state. For individual hospitals, once institutions had as few as 50 cases' total experience or performed just 10 cases annually, there was no clear improvement in outcomes. Patients in hospitals with fewer than 50 cases ever performed appeared objectively less sick compared with patients in hospital with more experience. We conclude that there is little evidence of volume-outcome relationships in adult ECMO in this state, although we acknowledge that the absence of clinical chart data limits these conclusions.

Interhospital ECMO Transport: Regional Focus

Utilization of extracorporeal membrane oxygenation (ECMO) has increased dramatically over the last decade. Despite this trend, many medical centers have limited, if any, access to this technology or the resources necessary to manage these complex patients. In an effort to improve the current infrastructure of regional ECMO care, ECMO centers of excellence have an obligation to partner with facilities within their communities and regions to increase access to this potentially life-saving technology. While the need for this infrastructure is widely acknowledged in the ECMO community, few reports describe the actual mechanisms by which a successful interfacility transport program can operate. As such, the purpose of this document is to describe the elements of and methods for providing safe and efficient mobile ECMO services from the perspective of an experienced, high-volume tertiary ECMO center of excellence in the Southeastern United States.

National trends in volume-outcome relationships for extracorporeal membrane oxygenation

BACKGROUND

The use of extracorporeal membrane oxygenation (ECMO) has emerged as a common therapy for severe cardiopulmonary dysfunction. We aimed to describe the relationship of institutional volume with patient outcomes and examine transfer status to tertiary ECMO centers.

MATERIALS AND METHODS

Using the National Inpatient Sample, we identified adult patients who received ECMO from 2008 to 2014. Individual hospital volume was calculated as tertiles of total institutional discharges for each year independently.

RESULTS

Of the total 18,684 adult patients placed on ECMO, 2548 (13.6%), 5278 (28.2%), and 10,858 (58.1%) patients were admitted to low-, medium-, and high-volume centers, respectively. Unadjusted mortality at low-volume hospitals was less than that of medium- (43.7% versus 50.3%, P = 0.03) and high-volume hospitals (43.7% versus 55.6%, P < 0.001). Length of stay and cost were reduced at low-volume hospitals compared to both medium- and large-volume institutions (all P < 0.001). In high-volume institutions, transferred patients had greater postpropensity-matched mortality (58.5% versus 53.7%, P = 0.05) and cost ($190,299 versus $168,970, P = 0.009) compared to direct admissions. On exclusion of transferred patients from propensity analysis, mortality remained greater in high-volume compared to low-volume centers (50.2% versus 42.8%, P = 0.04). Predictors of mortality included treatment at high-volume centers, respiratory failure, and cardiogenic shock (all P < 0.001).

CONCLUSIONS

Our findings show increased in-hospital mortality in high-volume institutions and in patients transferred to tertiary centers. Whether this phenomenon represents selection bias or transfer from another facility deserves further investigation and will aid with the identification of surrogate markers for quality of high-risk interventions.

Weaning from prolonged veno-venous extracorporeal membrane oxygenation (ECMO) after transfer to a specialized center: a retrospective study

Veno-venous extracorporeal membrane oxygenation (vvECMO) is increasingly used as rescue therapy in severe respiratory failure. In patients with pre-existent lung diseases or persistent lung injury weaning from vvECMO can be challenging. This study sought to investigate outcomes of patients transferred to a specialized ECMO center after prolonged ECMO therapy. We performed a retrospective analysis of all patients admitted to our medical intensive care unit (ICU) between 01/2013 and 12/2016 who were transferred from an external ICU after > 8 days on vvECMO. 12 patients on ECMO for > 8 days were identified. Prior to transfer, patients underwent ECMO therapy for 18 ± 9.5 days. Total time on ECMO was 60 ± 46.6 days. 11/12 patients could be successfully weaned from ECMO, 7/12 in the first 28 days after transfer (8 ± 8.8 ECMO-free days at day 28). In 7 patients, ECMO could be terminated after at least partial lung recovery, in 4 patients after salvage lung transplant. No patient died or needed re-initiation of ECMO therapy at day 28. In summary, weaning from vvECMO was feasible even after prolonged ECMO courses and salvage lung transplant could be avoided in most cases. Patients may benefit from transfer to a specialized ECMO center.

The ICM research agenda on extracorporeal life support

PURPOSE

This study aimed to concisely describe the current standards of care, major recent advances, common beliefs that have been contradicted by recent trials, areas of uncertainty, and clinical studies that need to be performed over the next decade and their expected outcomes with regard to extracorporeal membrane oxygenation (ECMO).

METHODS

Narrative review based on a systematic analysis of the medical literature, national and international guidelines, and expert opinion.

RESULTS

The use of venovenous ECMO (VV-ECMO) is increasing in the most severe forms of acute lung injury. In patients with cardiogenic shock, short-term veno-arterial ECMO (VA-ECMO) provides both pulmonary and circulatory support. Technological improvements and recently published studies suggest that ECMO is able to improve patients' outcomes. There are, however, many uncertainties regarding the real benefits of this technique both in hemodynamic and respiratory failure, the territorial organization to deliver ECMO, the indications and the use of concomitant treatments.

CONCLUSIONS

Although there have been considerable advances regarding the use of ECMO in critically ill patients, the risk/benefit ratio remains underinvestigated. ECMO indications, organization of ECMO delivery, and use of adjuvant therapeutics need also to be explored. Ongoing and future studies may be able to resolve these issues.