Veno-venous extracorporeal membrane oxygenation in obese surgical patients with hypercapnic lung failure

Morbid obesity's impact on COVID-19 patients requiring venovenous extracorporeal membrane oxygenation: The covid-19 critical care consortium database review

Introduction: Obesity is associated with a worse prognosis in COVID-19 patients with acute respiratory distress syndrome (ARDS). Veno-venous (V-V) Extracorporeal Membrane Oxygenation (ECMO) can be a rescue option, however, the direct impact of morbid obesity in this select group of patients remains unclear.Methods: This is an observational study of critically ill adults with COVID-19 and ARDS supported by V-V ECMO. Data are from 82 institutions participating in the COVID-19 Critical Care Consortium international registry. Patients were admitted between 12 January 2020 to 27 April 2021. They were stratified based on Body Mass Index (BMI) at 40 kg/m2. The endpoint was survival to hospital discharge.Results: Complete data available on 354 of 401 patients supported on V-V ECMO. The characteristics of the high BMI (>40 kg/m2) and lower BMI (≤40 kg/m2) groups were statistically similar. However, the 'high BMI' group were comparatively younger and had a lower APACHE II score. Using survival analysis, older age (Hazard Ratio, HR 1.49 per-10-years, CI 1.25-1.79) and higher BMI (HR 1.15 per-5 kg/m2 increase, CI 1.03-1.28) were associated with a decreased patient survival. A safe BMI threshold above which V-V ECMO would be prohibitive was not apparent and instead, the risk of an adverse outcome increased linearly with BMI.Conclusion: In COVID-19 patients with severe ARDS who require V-V ECMO, there is an increased risk of death associated with age and BMI. The risk is linear and there is no BMI threshold beyond which the risk for death greatly increases.

Obesity and Extracorporeal Membrane Oxygenation (ECMO): Analysis of Outcomes

Traditionally, patients with obesity have been deemed ineligible for extracorporeal life support (ELS) therapies such as extracorporeal membrane oxygenation (ECMO), given the association of obesity with chronic health conditions that contribute to increased morbidity and mortality. Nevertheless, a growing body of literature suggests the feasibility, efficacy, and safety of ECMO in the obese population. This review provides an in-depth analysis of the current literature assessing the effects of obesity on outcomes among patients supported with ECMO (venovenous [VV] ECMO in noncoronavirus disease 2019 and coronavirus disease 2019 acute respiratory distress syndrome, venoarterial [VA] ECMO, and combined VV and VA ECMO), offer a possible explanation of the current findings on the basis of the obesity paradox phenomenon, provides a framework for future studies addressing the use of ELS therapies in the obese patient population, and provides guidance from the literature for many of the challenges related to initiating, maintaining, and weaning ELS therapy in patients with obesity.

Should Obesity Be an Exclusion Criterion for Extracorporeal Membrane Oxygenation Support? A Scoping Review

Obesity is often considered a contraindication to extracorporeal membrane oxygenation (ECMO) candidacy due to technical challenges with vascular access, higher cardiac output requirements, and known associations between obesity and overall increased morbidity and mortality due to chronic health conditions. However, a growing body of literature suggests that ECMO may be as safe and efficacious in both obese and nonobese patients. This scoping review provides a synthesis of the available literature on the outcomes of obese patients supported with (1) venovenous (VV)-ECMO in acute respiratory distress syndrome (ARDS) not due to coronavirus disease 2019 (COVID-19), (2) VV-ECMO in ARDS due to COVID-19, (3) venoarterial (VA)-ECMO for all indications, and (4) studies combining data of patients supported with VA- and VV-ECMO. A librarian-assisted search was performed using 4 primary electronic medical databases (PubMed, Web of Science, Excerpta Medica database [Embase], and Cochrane Library) from January 2003 to March 2023. Articles that reported outcomes of obese patients requiring ECMO support were included. Two reviewers independently screened titles, abstracts, and full text of articles to determine eligibility. Data extraction was performed using customized fields established a priori within a systematic review software system. A total of 354 publications were imported for screening on titles and abstracts, and 30 studies were selected for full-text review. A total of 26 publications met the inclusion criteria: 7 on VV-ECMO support in non-COVID-19 ARDS patients, 6 on ECMO in COVID-19 ARDS patients, 8 in patients supported with VA-ECMO, and 5 combining both VA- and VV-ECMO data. Although the included studies are limited to retrospective analyses and display a heterogeneity in definitions of obesity and comparison groups, the currently available literature suggests that outcomes and complications of ECMO therapy are equivalent in obese patients as compared to nonobese patients. Hence, obesity as measured by body mass index alone should not be considered an exclusion criterion in the decision to initiate ECMO.

Analgosedation in Critically Ill Adults Receiving Extracorporeal Membrane Oxygenation Support

Extracorporeal membrane oxygenation (ECMO) is an increasingly utilized intervention for cardiopulmonary failure. Analgosedation during ECMO support is essential to ensure adequate pain and agitation control and ventilator synchrony, optimize ECMO support, facilitate patient assessment, and minimize adverse events. Although the principles of analgosedation are likely similar for all critically ill patients, ECMO circuitry alters medication pharmacodynamics and pharmacokinetics. The lack of clinical guidelines for analgosedation during ECMO, especially at times of medication shortage, can affect patient management. Here, we review pharmacological considerations, protocols, and special considerations for analgosedation in critically ill adults receiving ECMO support.

Extracorporeal Membrane Oxygenation Rescue for Severe Aspiration Pneumonitis in Two Patients after Roux-en-y Gastric Bypass Procedure

Roux-en-y gastric bypass (RYGB) is one of the most common weight loss surgical procedures performed in the United States. Early post-operative small bowel obstruction is a rare but potentially morbid, complication of RYGB. We report two patients who underwent RYGB and required subsequent treatment for a post-operative small bowel obstruction. Their post-operative course was complicated by severe aspiration pneumonitis leading to hypoxemic respiratory failure requiring rescue with femoral veno-venous extracorporeal membrane oxygenation (V-V ECMO). Both patients were successfully extubated, weaned off V-V ECMO support, and discharged to home. These cases highlight the potential role of V-V ECMO for patients who have undergone RYGB and develop severe aspiration pneumonitis. They also highlight the need for cautionary use of gastrografin in RYGB patients. Early engagement of a multidisciplinary team experienced with adult ECMO is vital for favorable patient outcomes.

Contraindications to the Initiation of Veno-Venous ECMO for Severe Acute Respiratory Failure in Adults: A Systematic Review and Practical Approach Based on the Current Literature

(1) Background: Extracorporeal membrane oxygenation (ECMO) is increasingly used for acute respiratory failure with few absolute but many relative contraindications. The provider in charge often has a difficult time weighing indications and contraindications to anticipate if the patient will benefit from this treatment, a decision that often decides life and death for the patient. To assist in this process in coming to a good evidence-based decision, we reviewed the available literature. (2) Methods: We performed a systematic review through a literature search of the MEDLINE database of former and current absolute and relative contraindications to the initiation of ECMO treatment. (3) Results: The following relative and absolute contraindications were identified in the literature: absolute-refusal of the use of extracorporeal techniques by the patient, advanced stage of cancer, fatal intracerebral hemorrhage/cerebral herniation/intractable intracranial hypertension, irreversible destruction of the lung parenchyma without the possibility of transplantation, and contraindications to lung transplantation; relative-advanced age, immunosuppressed patients/pharmacological immunosuppression, injurious ventilator settings > 7 days, right-heart failure, hematologic malignancies, especially bone marrow transplantation and graft-versus-host disease, SAPS II score ≥ 60 points, SOFA score > 12 points, PRESERVE score ≥ 5 points, RESP score ≤ -2 points, PRESET score ≥ 6 points, and "do not attempt resuscitation" order (DN(A)R status). (4) Conclusions: We provide a simple-to-follow algorithm that incorporates absolute and relative contraindications to the initiation of ECMO treatment. This algorithm attempts to weigh pros and cons regarding the benefit for an individual patient and hopefully assists caregivers to make better, informed decisions.

The impact of obesity on outcomes in patients receiving extracorporeal life support

Extracorporeal life support (ECLS) has been increasingly utilized to manage cardiac and pulmonary dysfunction. The impact of obesity on outcomes of ECLS is poorly defined. The purpose of the study was to compare in-hospital mortality, resource use, complications, and readmissions in obese versus non-obese patients receiving ECLS. We performed a retrospective cohort study of all adult ECLS patients with and without an obesity diagnosis using the 2010-2016 Nationwide Readmissions Database (NRD). Mortality, length of stay (LOS), hospital charges, complications, and readmissions were evaluated using multivariable logistic and linear regression. Of 23 876, patients who received ECLS, 1924 (8.1%) were obese. Obese patients received ECLS more frequently for respiratory failure (29.5% vs. 23.7%, P = .001). After adjustment for patient and hospital factors, obesity was not associated with increased odds of mortality (AOR = 1.06, P = .44) and was associated with decreased LOS (13.7 vs. 21.2 days, P < .001), hospital charges ($171 866 vs. $211 445, P < .001), and 30-day readmission (AOR = 0.71, P = .03). Obesity was also associated with reduced odds of hemorrhage (AOR = 0.43, P < .001), neurologic complications (AOR = 0.55, P = .004), and acute kidney injury (AOR=0.83, P = .04). After stratification by ECLS indication, obesity remained predictive of shorter LOS (AOR range: 0.53-0.78, all P < .05 ) and did not impact mortality (all P > .05). Respiratory support remains the most common indication for ECLS among obese patients. Among all patients, as well as by individual ECLS indication, obesity was not associated with increased odds of mortality. These findings suggest that obesity should not be considered a high-risk contraindication to ECLS.

Obesity survival paradox in pneumonia supported with extracorporeal membrane oxygenation: Analysis of the national registry

PURPOSE

To investigate whether the obesity survival paradox, where obesity is associated with improved survival, exists for pneumonia supported with extracorporeal membrane oxygenation (ECMO).

MATERIALS AND METHODS

Between January 2014 and December 2015, 223 patients with acute respiratory failure who underwent ECMO in 11 hospitals in South Korea were enrolled retrospectively, and data relating to pneumonia cases were analyzed. Patients were divided into groups according to their pre-treatment body mass index (BMI): obese (BMI ≥ 25 kg/m²) and non-obese (BMI < 25 kg/m²). The BMI cut-off was adopted from the World Health Organization for Asian populations.

RESULTS

In total, 84 patients had pneumonia: obese group, 26; non-obese group, 58 (mean BMI, 27.8 vs. 21.4, p < 0.001). Pre-ECMO parameters and rescue therapy did not differ between the groups. The rate of successful weaning from ECMO was not different between the groups (76.9% vs. 72.4%, p = 0.753), but survival-to-discharge (73.1% vs. 36.2%, p = 0.002) and 6-month survival (69.2% vs. 36.2%, p = 0.005) rates were higher in the obese group. After adjusting for age and the pre-treatment PaO₂/FiO₂ ratio, low BMI was significantly associated with 6-month mortality (odds ratio 3.28, 95% confidence interval: 1.06-11.03, p = 0.044).

CONCLUSIONS

An obesity survival paradox exists in pneumonia supported with ECMO.

Drastic drop in blood flow of extracorporeal membrane oxygenation induced by an excessive increase in intra-abdominal pressure in an obese patient

Obesity and conditions that increase intra-abdominal pressure (IAP) should be considered as risk factors for reduced extracorporeal membrane oxygenation (ECMO) blood flow (BF) drastically. For obese patients on ECMO, effective IAP control and risk factor assessment is necessary to prevent excessive IAP elevation and subsequent drop in ECMO BF.

Effects of a physiotherapic program in patients on veno-venous extracorporeal membrane oxygenation: an 8-year single-center experience

BACKGROUND

To date, there is no agreement on the timing to perform a physical session in patients on veno-venous extracorporeal membrane oxygenation (VV-ECMO). We aimed to assess whether early physiotherapy (within the first week from ECMO start) could affect in-ICU mortality.

METHODS

Our retrospective observational study included 101 adults supported on VV ECMO from 2009 to 2016, consecutively admitted at our ECMO referral Center in Florence (Italy). Clinical data right before ECMO start were collected for all patients. The level of mobilization using the ICU mobility scale was recorded on the first session and at discharge.

RESULTS

Early physiotherapy (within the first week) was more frequently initiated in patients with lower BMI (P=0.013) and it was associated with lower duration of ECMO support (P=0.03), mechanical ventilation (P=0.001) and length of stay (P=0.001). In-ICU mortality was not different between the two subgroups.

CONCLUSIONS

In patients on VV-ECMO support, physiotherapy is feasible and safe and that early physiotherapy, initiated within the first week from ECMO start, is associated with shorter duration of ECMO support and ICU length of stay.

ARDS in Obese Patients: Specificities and Management

This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2019. Other selected articles can be found online at https://www.biomedcentral.com/collections/annualupdate2019. Further information about the Annual Update in Intensive Care and Emergency Medicine is available from http://www.springer.com/series/8901.

Morbid obesity is not a contraindication to transport on extracorporeal support

OBJECTIVES

Extracorporeal membrane oxygenation (ECMO) transport has not been described in morbidly obese patients, a population that can pose significant challenges in obtaining vascular access, indexed flows and transport logistics. We sought to study the feasibility and safety of transporting obese and morbidly obese patients during extracorporeal support.

METHODS

We conducted a retrospective review of all patients transported to our institution while receiving ECMO from September 2008 to September 2016. Survival to decannulation and survival to discharge were the primary outcomes. Obesity and morbid obesity were defined as a body mass index of greater than 30 kg/m2 and greater than 40 kg/m2, respectively.

RESULTS

From 2008 to 2016, 222 patients were transported to our institution while receiving ECMO. Among these included patients, 131 were non-obese (interquartile range 22-27 kg/m2), 63 were obese (interquartile range 31-35 kg/m2) and 28 were morbidly obese (interquartile range 41-49 kg/m2), with 6 patients having a body mass index greater than 50 kg/m2 (range 52.3-79 kg/m2). Pre-ECMO arterial blood gases, disease severity indices, cannulation strategies and transport distances were similar between these 3 groups. There was no mortality of patients during transport, and survival to discharge was 66% (n = 87) in non-obese patients, 56% (n = 35) in obese patients and 82% (n = 23) in morbidly obese patients (P = 0.042). On multivariable logistic regression analysis, body mass index was not a predictor of in-hospital mortality (odds ratio 0.99, 95% confidence interval 0.95-1.03; P = 0.517).

CONCLUSIONS

Transport of morbidly obese patients receiving ECMO may be performed safely and with excellent results in the setting of a dedicated ECMO transport programme with well-established management protocols.

Venovenous Extracorporeal Membrane Oxygenation in Two Morbidly Obese Patients

Case studies on the use of venovenous extracorporeal membrane oxygenation in the obese patient have been infrequently reported. We report the successful utilization of venovenous extracorporeal membrane oxygenation in two obese patients with acute respiratory distress syndrome. The first patient had a body mass index of 93 and developed acute respiratory distress syndrome in the setting of pneumonia and aspiration while the second patient had a body mass index of 47 and developed acute respiratory distress syndrome in the setting of gastrografin aspiration. Both were successfully managed with venovenous extracorporeal membrane oxygenation and discharged from the hospital.

Venovenous Extracorporeal Membrane Oxygenation as a Treatment for Obesity Hypoventilation Syndrome

The mortality rate for respiratory failure resulting from obesity hypoventilation syndrome is high if it requires ventilator management. We describe a case of severe acute respiratory failure resulting from obesity hypoventilation syndrome (BMI, 60.2 kg/m²) successfully treated with venovenous extracorporeal membrane oxygenation (VV-ECMO). During ECMO management, a mucus plug was removed by bronchoscopy daily and 18 L of water was removed using diuretics, resulting in weight loss of 24 kg. The patient was weaned from ECMO on day 5, extubated on day 16, and discharged on day 21. The fundamental treatment for obesity hypoventilation syndrome in morbidly obese patients is weight loss. VV-ECMO can be used for respiratory support until weight loss has been achieved.

Class III Obesity is Not a Contraindication to Venovenous Extracorporeal Membrane Oxygenation Support

BACKGROUND

The use of venovenous extracorporeal membrane oxygenation (ECMO) has increased as a bridge to recovery for acute respiratory distress syndrome (ARDS) refractory to conventional support. Morbid obesity can pose a significant challenge to obtaining indexed flows, and outcomes in this population are not well described.

METHODS

Patients requiring ECMO for ARDS between January 2009 and November 2012 were retrospectively reviewed. Demographics, ECMO variables, and outcomes were assessed. Morbid obesity and super obesity were defined as a body mass index (BMI) greater than 40 kg/m(2) and greater than 50 kg/m(2), respectively.

RESULTS

Fifty-five patients with ARDS were placed on ECMO during the study period. Twelve were morbidly obese with a BMI of 49.0 kg/m(2) (interquartile range [IQR]: 45.4-57.3 kg/m(2)). Pre-ECMO mechanical ventilatory support and indices of disease severity were similar between the 2 groups, as were cannulation strategy and duration of ECMO support. Nine (75%) morbidly obese patients and 27 (63%) non-morbidly obese patients were successfully weaned from ECMO support, and patient survival to time of discharge was 67% and 58%, respectively. In the subset of super obese patients (n = 6; BMI, 57.3 kg/m(2) [IQR: 51.3-66.5 kg/m(2)]), recovery and midterm survival was 100%.

CONCLUSIONS

In this review, class III obesity was not associated with poorer outcomes, and based on these data, ECMO support should not be withheld from this patient population.