Central extracorporeal membrane oxygenation requiring pulmonary arterial venting after near-drowning

Perioperative extracorporeal membrane oxygenation in pediatric congenital heart disease: Chinese expert consensus

BACKGROUND

Congenital heart disease (CHD) is one of the main supportive diseases of extracorporeal membrane oxygenation in children. The management of extracorporeal membrane oxygenation (ECMO) for pediatric CHD faces more severe challenges due to the complex anatomical structure of the heart, special pathophysiology, perioperative complications and various concomitant malformations. The survival rate of ECMO for CHD was significantly lower than other classifications of diseases according to the Extracorporeal Life Support Organization database. This expert consensus aims to improve the survival rate and reduce the morbidity of this patient population by standardizing the clinical strategy.

METHODS

The editing group of this consensus gathered 11 well-known experts in pediatric cardiac surgery and ECMO field in China to develop clinical recommendations formulated on the basis of existing evidences and expert opinions.

RESULTS

The primary concern of ECMO management in the perioperative period of CHD are patient selection, cannulation strategy, pump flow/ventilator parameters/vasoactive drug dosage setting, anticoagulation management, residual lesion screening, fluid and wound management and weaning or transition strategy. Prevention and treatment of complications of bleeding, thromboembolism and brain injury are emphatically discussed here. Special conditions of ECMO management related to the cardiovascular anatomy, haemodynamics and the surgical procedures of common complex CHD should be considered.

CONCLUSIONS

The consensus could provide a reference for patient selection, management and risk identification of perioperative ECMO in children with CHD. Video abstract (MP4 104726 kb).

Venting during venoarterial extracorporeal membrane oxygenation

Cardiogenic shock and cardiac arrest contribute pre-dominantly to mortality in acute cardiovascular care. Here, veno-arterial extracorporeal membrane oxygenation (VA-ECMO) has emerged as an established therapeutic option for patients suffering from these life-threatening entities. VA-ECMO provides temporary circulatory support until causative treatments are effective and enables recovery or serves as a bridging strategy to surgical ventricular assist devices, heart transplantation or decision-making. However, in-hospital mortality rate in this treatment population is still around 60%. In the recently published ARREST trial, VA-ECMO treatment lowered mortality rate in patients with ongoing cardiac arrest due to therapy refractory ventricular fibrillation compared to standard advanced cardiac life support in selected patients. Whether VA-ECMO can reduce mortality compared to standard of care in cardiogenic shock has to be evaluated in the ongoing prospective randomized studies EURO-SHOCK (NCT03813134) and ECLS-SHOCK (NCT03637205). As an innate drawback of VA-ECMO treatment, the retrograde aortic flow could lead to an elevation of left ventricular (LV) afterload, increase in LV filling pressure, mitral regurgitation, and elevated left atrial pressure. This may compromise myocardial function and recovery, pulmonary hemodynamics—possibly with concomitant pulmonary congestion and even lung failure—and contribute to poor outcomes in a relevant proportion of treated patients. To overcome these detrimental effects, a multitude of venting strategies are currently engaged for both preventive and emergent unloading. This review aims to provide a comprehensive and structured synopsis of existing venting modalities and their specific hemodynamic characteristics. We discuss in detail the available data on outcome categories and complication rates related to the respective venting option.

Graphical abstract

Comparison of left ventricular unloading strategies on venoarterial extracorporeal life support

OBJECTIVES

Our goal was to compare the haemodynamic effects of different mechanical left ventricular (LV) unloading strategies and clinical outcomes in patients with refractory cardiogenic shock supported with venoarterial extracorporeal membrane oxygenation (VA-ECMO).

METHODS

A total of 448 patients supported with VA-ECMO for refractory cardiogenic shock between 1 March 2015 and 31 January 2020 were included and analysed in a single-centre, retrospective case-control study. Fifty-three patients (11.8%) on VA-ECMO required LV unloading. Percutaneous balloon atrial septostomy (PBAS), intra-aortic balloon pump (IABP) and transapical LV vent (TALVV) strategies were compared with regards to the composite rate of death, procedure-related complications and neurological complications. The secondary outcomes were reduced pulmonary capillary wedge pressure, pulmonary artery pressure, central venous pressure, left atrial diameter and resolution of pulmonary oedema on a chest X-ray within 48 h.

RESULTS

No death related to the LV unloading procedure was detected. Reduction in pulmonary capillary wedge pressure was highest with the TALVV technique (17.2 ± 2.1 mmHg; P < 0.001) and was higher in the PBAS than in the IABP group; the difference was significant (9.6 ± 2.5 and 3.9 ± 1.3, respectively; P = 0.001). Reduction in central venous pressure with TALVV was highest with the other procedures (7.4 ± 1.1 mmHg; P < 0.001). However, procedure-related complications were significantly higher with TALVV compared to the PBAS and IABP groups (50% vs 17.6% and 10%, respectively; P = 0.015). We observed no significant differences in mortality or neurological complications between the groups.

CONCLUSIONS

Our results suggest that TALVV was the most effective method for LV unloading compared with PBAS and IABP for VA-ECMO support but was associated with complications. Efficient LV unloading may not improve survival.

Pulmonary artery cannulation to enhance extracorporeal membrane oxygenation management in acute cardiac failure

OBJECTIVES

Pulmonary artery (PA) cannulation during peripheral venoarterial extracorporeal membrane oxygenation (ECMO) has been shown to be effective either for indirect left ventricular (LV) unloading or to allow right ventricular (RV) bypass with associated gas-exchange support in case of acute RV with respiratory failure. This case series reports the results of such peculiar ECMO configurations with PA cannulation in different clinical conditions.

METHODS

All consecutive patients receiving PA cannulation (direct or percutaneous) from January 2015 to September 2018 in 3 institutions were retrospectively reviewed. Isolated LV unloading or RV support, as well as dynamic support including initial drainage followed by perfusion through the PA cannula, was used as part of the ECMO configuration according to the type of patient and the patient's haemodynamic/functional needs.

RESULTS

Fifteen patients (8 men, age range 45-73 years, EuroSCORE log range 14.45-91.60%) affected by acute LV, RV or biventricular failure of various aetiologies, were supported by this ECMO mode. Percutaneous PA cannulation was performed in 10 patients and direct PA cannulation, in 5 cases. Dynamic ECMO management (initially draining and then perfusing through the PA cannula) was carried out in 6 patients. Mean ECMO duration was 9.1 days (range 6-17 days). One patient exhibited pericardial fluid during the implant of a PA cannula (no lesion found when the chest was opened), and weaning from temporary circulatory support was achieved in 14 patients (1 who received a transplant). Three patients (20%) died in-hospital, and 12 patients were successfully discharged without major complications.

CONCLUSIONS

Effective indirect LV unloading in peripheral venoarterial ECMO as well as isolated RV support can be achieved by PA cannulation. Such an ECMO configuration may allow the counteraction of common venoarterial ECMO shortcomings or allow dynamic/adjustable management of ECMO according to specific ventricular dysfunction and haemodynamic needs. Percutaneous PA cannulation was shown to be safe and feasible without major complications. Additional investigation is needed to confirm the safety and efficacy of such an ECMO configuration and management in a larger patient population.

Extracorporeal life support in the emergency department: A narrative review for the emergency physician

BACKGROUND

Extracorporeal life support (ECLS) describes the use of blood perfusion devices to provide advanced cardiac or respiratory support. Advances in percutaneous vascular cannula insertion, centrifugal pump technologies, and the miniaturization of extracorporeal devices have simplified ECLS. The intention of this discussion is to review the role of ECLS as a potential rescue method for emergency department (ED) clinicians in critical clinical scenarios and to focus on the prerequisites for managing an ECLS program in an ED setting.

DISCUSSION

Possible indications for ECLS cannulation in the ED include ongoing circulatory arrest, shock or refractory hypoxemia and pulmonary embolism with refractory shock. Severe trauma, foreign body obstruction, hypothermia and near drowning are situations in which patients may potentially benefit from ECLS. Early stabilization in the ED can provide a time window for a diagnostic workup and/or urgent procedures, including percutaneous coronary intervention, rewarming or damage control surgery in trauma. The use of ECLS is resource intensive and can be associated with a high risk of complications, especially when performed without previous training. Therefore, ECLS should only be used when the underlying problem is potentially reversible, and the resources are available to address the etiology of organ dysfunction.

CONCLUSION

Emergent ECLS has a role in the ED for selected indications in the face of life-threatening conditions. ECLS provides a bridge to recovery, definitive therapy, intervention or surgery. ECLS program requires an appropriately trained staff (physicians, nurses and ECLS specialists), equipment resources and logistical planning.

Left ventricular unloading during veno-arterial ECMO: a review of percutaneous and surgical unloading interventions

Short-term mechanical support by veno-arterial extracorporeal membrane oxygenation (VA ECMO) is more and more applied in patients with severe cardiogenic shock. A major shortcoming of VA ECMO is its variable, but inherent increase of left ventricular (LV) mechanical load, which may aggravate pulmonary edema and hamper cardiac recovery. In order to mitigate these negative sequelae of VA ECMO, different adjunct LV unloading interventions have gained a broad interest in recent years. Here, we review the whole spectrum of percutaneous and surgical techniques combined with VA ECMO reported to date.

Modalities and Effects of Left Ventricle Unloading on Extracorporeal Life support: a Review of the Current Literature

INTRODUCTION/AIM

Veno-arterial extracorporeal membrane oxygenation (V-A ECMO) support is increasingly used in refractory cardiogenic shock and cardiac arrest, but is characterized by a rise in afterload of the left ventricle (LV) which may ultimately either further impair or delay cardiac contractility improvement. The aim of this study was to provide a comprehensive overview regarding the different LV venting techniques and results currently available in the literature.

METHODS

A systematic literature search was performed in the PubMed database: 207 articles published between 1993 and 2016 were included. Papers dealing with pre-clinical studies, overlapping series, and association with other assist devices were excluded from the review, with 45 published papers finally selected. Heterogeneous indications for LV unloading were reported. The selected literature was divided into subgroups, according to the location or the performed procedure for LV venting.

RESULTS

Case reports or case series accounted for 60% of the papers, while retrospective study represented 29% of them. Adult series were present in 67%, paediatric patients in 29%, and a mixed population in 4%. LV unloading was performed percutaneously in 84% of the cases. The most common locations of unloading was the left atrium (31%), followed by indirect unloading (intra-aortic balloon pump) (27%), trans-aortic (27%), LV (11%), and pulmonary artery (4%). Percutaneous trans-septal approach was reported in 22%. Finally, the unloading was conducted surgically in 16%,with open chest surgery in 71%, and minimally invasive surgery in 29% of surgical cases.

CONCLUSION

Nowadays, only a few data are available about left heart unloading in V-A ECMO support. Despite the well-known controversy, IABP remains widely used in combination with V-A ECMO. Percutaneous approaches utilizing unloading devices is becoming an increasingly used option. However, further studies are required to establish the optimal LV unloading method.