Extracorporeal Membrane Oxygenation in COVID-19 Treatment: a Systematic Literature Review

Outcomes following additional drainage during veno-venous extracorporeal membrane oxygenation: A single-center retrospective study

Refractory hypoxemia during veno-venous (V-V) extracorporeal membrane oxygenation (ECMO) may require an additional cannula (VV-V ECMO) to improve oxygenation. This intervention includes risk of recirculation and other various adverse events (AEs) such as injury to the lung, cannula malpositioning, bleeding, circuit or cannula thrombosis requiring intervention (i.e., clot), or cerebral injury. During the study period, 23 of 142 V-V ECMO patients were converted to VV-V utilizing two separate cannulas for bi-caval drainage with an additional upper extremity cannula placed for return. Of those, 21 had COVID-19. In the first 24 h after conversion, ECMO flow rates were higher (5.96 vs 5.24 L/min, p = .002) with no significant change in pump speed (3764 vs 3630 revolutions per minute [RPMs], p = .42). Arterial oxygenation (PaO2) increased (87 vs 64 mmHg, p < .0001) with comparable pre-oxygenator venous saturation (61 vs 53.3, p = .12). By day 5, flows were similar to pre-conversion values at lower pump speed but with improved PaO2. Unadjusted survival was similar in those converted to VV-V ECMO compared to V-V ECMO alone (70% [16/23] vs 66.4% [79/119], p = .77). In a mixed effect regression model, any incidence of AEs, demonstrated a negative impact on PaO2 in the first 48 h but not at day 5. VV-V ECMO improved oxygenation with increasing flows without a significant difference in AEs or pump speed. AEs transiently impacted oxygenation. VV-V ECMO is effective and feasible strategy for refractory hypoxemia on VV-ECMO allowing for higher flow rate and unchanged pump speed.

The global economic burden of COVID-19 disease: a comprehensive systematic review and meta-analysis

BACKGROUND

The COVID-19 pandemic has caused a considerable threat to the economics of patients, health systems, and society.

OBJECTIVES

This meta-analysis aims to quantitatively assess the global economic burden of COVID-19.

METHODS

A comprehensive search was performed in the PubMed, Scopus, and Web of Science databases to identify studies examining the economic impact of COVID-19. The selected studies were classified into two categories based on the cost-of-illness (COI) study approach: top-down and bottom-up studies. The results of top-down COI studies were presented by calculating the average costs as a percentage of gross domestic product (GDP) and health expenditures. Conversely, the findings of bottom-up studies were analyzed through meta-analysis using the standardized mean difference.

RESULTS

The implemented search strategy yielded 3271 records, of which 27 studies met the inclusion criteria, consisting of 7 top-down and 20 bottom-up studies. The included studies were conducted in various countries, including the USA (5), China (5), Spain (2), Brazil (2), South Korea (2), India (2), and one study each in Italy, South Africa, the Philippines, Greece, Iran, Kenya, Nigeria, and the Kingdom of Saudi Arabia. The results of the top-down studies indicated that indirect costs represent 10.53% of GDP, while the total estimated cost accounts for 85.91% of healthcare expenditures and 9.13% of GDP. In contrast, the bottom-up studies revealed that the average direct medical costs ranged from US $1264 to US $79,315. The meta-analysis demonstrated that the medical costs for COVID-19 patients in the intensive care unit (ICU) were approximately twice as high as those for patients in general wards, with a range from 0.05 to 3.48 times higher.

CONCLUSIONS

Our study indicates that the COVID-19 pandemic has imposed a significant economic burden worldwide, with varying degrees of impact across countries. The findings of our study, along with those of other research, underscore the vital role of economic consequences in the post-COVID-19 era for communities and families. Therefore, policymakers and health administrators should prioritize economic programs and accord them heightened attention.

Factors related to lung function outcomes in critically ill COVID-19 patients in South Korea

BACKGROUND

New variants of the virus responsible for the coronavirus disease 2019 (COVID-19) pandemic continue to emerge. However, little is known about the effect of these variants on clinical outcomes. This study evaluated the risk factors for poor pulmonary lung function test (PFT).

METHODS

The study retrospectively analyzed 87 patients in a single hospital and followed up by performing PFTs at an outpatient clinic from January 2020 to December 2021. COVID-19 variants were categorized as either a non-delta variant (November 13, 2020-July 6, 2021) or the delta variant (July 7, 2021-January 29, 2022).

RESULTS

The median age of the patients was 62 years, and 56 patients (64.4%) were male. Mechanical ventilation (MV) was provided for 52 patients, and 36 (41.4%) had restrictive lung defects. Forced vital capacity (FVC) and diffusion capacity of the lung for carbon monoxide (DLCO ) were lower in patients on MV. Male sex (odds ratio [OR], 0.228) and MV (OR, 4.663) were significant factors for decreased DLCO . The duration of MV was associated with decreased FVC and DLCO . However, the type of variant did not affect the decrease in FVC (P=0.750) and DLCO (P=0.639).

CONCLUSIONS

Among critically ill COVID-19 patients, 40% had restrictive patterns with decreased DLCO . The reduction of PFT was associated with MV, type of variants.

Incidence and inhospital outcomes of coronavirus disease 2019-associated pulmonary aspergillosis in the United States

OBJECTIVE

The aim of this study was to estimate the predictors, associations, and outcomes of COVID-19-associated pulmonary disease (CAPA) in the United States.

STUDY DESIGN AND METHODS

This retrospective cohort study was performed by using the National Inpatient Sample Database 2020 to identify coronavirus disease 2019 (COVID-19) and CAPA hospitalizations. Baseline variables and outcomes were compared between COVID-19 hospitalizations without aspergillosis and those with aspergillosis. These variables were then used to perform an adjusted analysis for obtaining predictors and factors associated with CAPA and its inhospital mortality.

RESULTS

Of the 1,020,880 hospitalizations identified with the principal diagnosis of COVID-19, CAPA was identified in 1510 (0.1%) hospitalizations. The CAPA cohort consisted of a higher proportion of males (58%) as well as racial and ethnic minorities (Hispanics, Blacks, and others [including Asian or Pacific islanders, native Americans]). Inhospital mortality was significantly higher (47.35% vs. 10.87%, P < 0.001), the average length of stay was longer (27.61 vs. 7.29 days, P < 0.001), and the mean cost per hospitalization was higher ($121,560 vs. $18,423, P < 0.001) in the CAPA group compared to COVID-19 without aspergillosis. History of solid organ transplant, chronic obstructive pulmonary disease, and venous thromboembolism were associated with higher odds of CAPA among other factors. The use of invasive mechanical ventilation (adjusted odds ratio [aOR] 6.24, P < 0.001), acute kidney injury (aOR 2.02, P = 0.028), and septic shock (aOR 2.07, P = 0.018) were associated with higher inhospital mortality in the CAPA cohort.

CONCLUSION

While CAPA is an infrequent complication during hospitalizations for COVID-19, it significantly increases all-cause mortality, prolongs hospital stays, and leads to higher hospital expenses compared to COVID-19 cases without aspergillosis.

Multi-horizon predictive models for guiding extracorporeal resource allocation in critically ill COVID-19 patients

OBJECTIVE

Extracorporeal membrane oxygenation (ECMO) resource allocation tools are currently lacking. We developed machine learning (ML) models for predicting COVID-19 patients at risk of receiving ECMO to guide patient triage and resource allocation.

MATERIAL AND METHODS

We included COVID-19 patients admitted to intensive care units for >24 h from March 2020 to October 2021, divided into training and testing development and testing-only holdout cohorts. We developed ECMO deployment timely prediction model ForecastECMO using Gradient Boosting Tree (GBT), with pre-ECMO prediction horizons from 0 to 48 h, compared to PaO2/FiO2 ratio, Sequential Organ Failure Assessment score, PREdiction of Survival on ECMO Therapy score, logistic regression, and 30 pre-selected clinical variables GBT Clinical GBT models, with area under the receiver operator curve (AUROC) and precision recall curve (AUPRC) metrics.

RESULTS

ECMO prevalence was 2.89% and 1.73% in development and holdout cohorts. ForecastECMO had the best performance in both cohorts. At the 18-h prediction horizon, a potentially clinically actionable pre-ECMO window, ForecastECMO, had the highest AUROC (0.94 and 0.95) and AUPRC (0.54 and 0.37) in development and holdout cohorts in identifying ECMO patients without data 18 h prior to ECMO.

DISCUSSION AND CONCLUSIONS

We developed a multi-horizon model, ForecastECMO, with high performance in identifying patients receiving ECMO at various prediction horizons. This model has potential to be used as early alert tool to guide ECMO resource allocation for COVID-19 patients. Future prospective multicenter validation would provide evidence for generalizability and real-world application of such models to improve patient outcomes.

The Year in Extracorporeal Membrane Oxygenation: Selected Highlights From 2021

This review summarizes the extracorporeal membrane oxygenation (ECMO) or extracorporeal life support literature published in 2021. This Selected Highlights article is not intended to be an exhaustive review of the literature, but rather a summarizing of key themes that developed in the ECMO literature during 2021. The primary topics presented include the following: ECMO for coronavirus disease 2019, extracorporeal cardiopulmonary resuscitation, periprocedural cardiopulmonary support with ECMO, and anticoagulation for ECMO.

Extracorporeal Membrane Oxygenation Used in Acute Respiratory Distress Syndrome with COVID-19: A Systematic Review and Meta-Analysis

Introduction

Protective pulmonary mechanical ventilation, higher positive end-expiratory pressure, neuromuscular blockade, prone positioning, and pulmonary recruitment procedures are all strategies in severe COVID-19 cases. Extracorporeal Membrane Oxygenation (ECMO) can be seen as an alternative to traditional treatment in certain patients when conventional therapy fails. We present a study that intends to systematically review and meta-analysis ECMO use in COVID-19 patients.

Methods

We search major medical databases (Cochrane Library, PubMed, EMBASE, MedRxiv) for clinical trials that were released between January 2020 until February 2021, had full-text availability, were written in English, and humans studies.

We used National Heart, Lung, and Blood Institute (NHLBI) quality evaluation methods for retrospective cohort and cross-sectional studies to evaluate the quality of the articles. In addition, we used the Mantel–Haenszel random-effects meta-analysis of using RevMan 5.4.

Results

A total of 33 studies involving 3090 patients were included in the systematic review and six studies in the meta-analysis. There were 828 patients admitted to the ICU, of which 779 patients had ARDS (94%). Of the total study, 527 patients received ECMO therapy (17%). ARDS incidence was associated with complications during ICU care compared to non-ICU care (OR 107.98; 95% CI 55.51–210.03; p < 0.00001). Indirect comparisons, the incidence of mortality was associated with ECMO compared with non-ECMO (OR 15.79; 95% CI 4.21–59.28; p < 0.0001).

Conclusion

The incidence of ARDS was associated with complications during ICU stay, and the incidence of mortality was associated with ECMO. Further study about mechanisms involving illness and death of patients from COVID-19 is needed.