Outcomes of patients with acute respiratory failure on veno-venous extracorporeal membrane oxygenation requiring additional circulatory support by veno-venoarterial extracorporeal membrane oxygenation

Transplantation, bridging, and support technologies in pulmonary hypertension

Despite the progress made in medical therapies for treating pulmonary hypertension (PH), a subset of patients remain susceptible to developing a maladaptive right ventricular phenotype. The effective management of end-stage PH presents substantial challenges, necessitating a multidisciplinary approach and early identification of patients prone to acute decompensation. Identifying potential transplant candidates and assessing the feasibility of such a procedure are pivotal tasks that should be undertaken early in the treatment algorithm. Inclusion on the transplant list is contingent upon a comprehensive risk assessment, also considering the specific type of PH and various factors affecting waiting times, all of which should inform the decision-making process. While bilateral lung transplantation is the preferred option, it demands expert intra- and post-operative management to mitigate the heightened risks of pulmonary oedema and primary graft dysfunction in PH patients. Despite the availability of risk assessment tools, the occurrence of acute PH decompensation episodes can be unpredictable, potentially leading to refractory right ventricular failure even with optimal medical intervention, necessitating the use of rescue therapies. Advancements in right ventricular assist techniques and adjustments to graft allocation protocols for the most critically ill patients have significantly enhanced the survival in intensive care, affording the opportunity to endure while awaiting an urgent transplant. Given the breadth of therapeutic options available, specialised centres capable of delivering comprehensive care have become indispensable for optimising patient outcomes. These centres are instrumental in providing holistic support and management tailored to the complex needs of PH patients, ultimately enhancing their chances of a successful transplant and improved long-term prognosis.

Veno-Venoarterial Extracorporeal Membrane Oxygenation for Septic Cardiomyopathy Caused by Invasive Pneumococcal Infection: A Case Report

The efficacy of extracorporeal membrane oxygenation (ECMO) for circulatory support in septic shock, especially hybrid ECMO, remains uncertain. A 30-year-old woman presented with septic shock caused by invasive pneumococcal infection, requiring intensive care unit (ICU) admission. Despite maximal respiratory support, her condition worsened with a partial pressure of oxygen (PaO2)/fraction of inspired oxygen (FiO2) ratio < 60 (The ratio is an indicator of respiratory oxygenation), indicating severe hypoxia and requiring the initiation of veno-venous (V-V) ECMO within three hours. Progressive circulatory failure followed, marked by reduced cardiac function indicative of septic cardiomyopathy; septic cardiomyopathy is a reversible myocardial dysfunction that occurs in patients with sepsis. Transition to veno-venoarterial (V-VA) ECMO took place 13 hours after admission. Liberation from veno-arterial (V-A) ECMO on day 9 and V-V ECMO on day 16 paralleled improvements in circulatory and respiratory functions. Necrosis of both lower extremities, pneumonia and bloodstream infection caused by Pseudomonas aeruginosa, prolonged ICU stay until discharge on day 52. Weaned off the ventilator, and with fully recovered consciousness and cardiac function, she was transferred to a rehabilitation facility on day 89. At follow-up more than six months after disease onset, she was doing well and continuing rehabilitation. This case enhances our understanding that when septic cardiomyopathy causes circulatory failure early in the treatment of septic shock, ECMO can serve as life-saving circulatory support. Additionally, the successful use of V-VA ECMO in this case highlights its potential as a therapeutic strategy for patients with severe respiratory failure complicated by septic cardiomyopathy, especially those initially managed with V-V ECMO. Timely transition to V-VA ECMO may improve outcomes in septic patients receiving V-V ECMO when cardiac dysfunction worsens due to septic cardiomyopathy.

A Descriptive Analysis of Hybrid Cannulated Extracorporeal Life Support

BACKGROUND

Extracorporeal life support (ECLS) is pivotal for sustaining the function of failing hearts and lungs, and its utilization has risen. In cases where conventional cannulation strategies prove ineffective for providing adequate ECLS support, the implementation of an enhanced system with a third cannula may become necessary. Hybrid ECLS may be warranted in situations characterized by severe hypoxemia of the upper extremity, left ventricular congestion, and dilatation. Additionally, it may also be considered for patients requiring respiratory support or experiencing hemodynamic instability.

METHOD

All hybrid ECLS cases of adults at the University Hospital Zurich, Switzerland, between January 2007 and December 2019 with initial triple cannulation were included. Data were collected via a retrospective review of patient records and direct export of the clinical information system.

RESULTS

28 out of 903 ECLS cases were initially hybrid cannulated (3.1%). The median age was 57 (48.2 to 60.8) years, and the sex was equally distributed. The in-hospital mortality of hybrid ECLS was high (67.9%). In-hospital mortality rates differ depending on the indication (ARDS: 36.4%, refractory cardiogenic shock: 88.9%, cardiopulmonary resuscitation: 100%, post-cardiotomy: 100%, others: 75%). Survivors exhibited a lower SAPS II level compared with non-survivors (20.0 (12.0 to 65.0) vs. 55.0 (45.0 to 73.0)), and the allogenic transfusion of platelet concentrate was observed to be less frequent for survivors (0.0 (0.0) vs. 1.8 (2.5) units).

CONCLUSION

The in-hospital mortality rate for hybrid ECLS was high. Different indications showed varying mortality rates, with survivors having lower SAPS II scores and requiring fewer platelet concentrate transfusions. These findings highlight the complexities of hybrid ECLS outcomes in different clinical scenarios and underline the importance of rigorous patient selection.

What Factors Are Associated With Arterial Line-Related Limb Ischemia in Patients on Extracorporeal Membrane Oxygenation? A Single-Center Retrospective Cohort Study

OBJECTIVES

The primary purpose of this study was to identify factors associated with the development of arterial line-related limb ischemia in patients on extracorporeal membrane oxygenation (ECMO). The authors also sought to characterize and report the outcomes of patients who developed arterial line-related limb ischemia.

DESIGN

Retrospective cohort study.

SETTING

A single academic tertiary referral ECMO center.

PARTICIPANTS

Consecutive patients who were treated with ECMO over 6 years.

INTERVENTIONS

Use of arterial line.

MEASUREMENTS AND MAIN RESULTS

A total of 278 consecutive ECMO patients were included, with 19 (7%) patients developing arterial line-related limb ischemia during the ECMO run. Postcannulation Sequential Organ Failure Assessment (SOFA) (adjusted odds ratio [aOR] 1.20, 95% CI 1.08-1.32), Acute Physiology and Chronic Health Evaluation-II (aOR 0.84, 95% CI 0.74-0.95), and adjusted Vasopressor Dose Equivalence (aOR 1.03, 95% CI 1.01-1.05) scores were independently associated with the development of arterial line-associated limb ischemia. A SOFA score of ≥17 at the time of ECMO cannulation had an 80% sensitivity and 87% specificity for predicting arterial line-related limb ischemia.

CONCLUSIONS

Arterial line-related limb ischemia is much more common in ECMO patients than in the typical intensive care unit setting. The SOFA score may be useful in identifying which patients may be at risk for arterial line-related limb ischemia. As this was a single-center retrospective study, these results are inherently exploratory, and prospective multicenter studies are necessary to validate these results.

Extracorporeal Life Support in Pulmonary Hypertension: Practical Aspects

Extracorporeal life support (ECLS), in particular veno-arterial extracorporeal membrane oxygenation, has emerged as a potentially life-saving treatment modality in patients presenting with pulmonary hypertension and right heart failure refractory to conventional treatment. Used mainly as a bridge to lung transplantation, ECLS is also being used occasionally as a bridge to recovery in patients with treatable causes of right heart failure. This review article describes indications, contraindications, techniques, and outcomes of the use of ECLS in patients with PH, focusing on practical aspects in the management of such patients.