Retrieval of critically ill adults using extracorporeal membrane oxygenation: the nine-year experience in New South Wales

Emergency critical care: closing the gap between onset of critical illness and intensive care unit admission

Critical illness is an exquisitely time-sensitive condition and follows a disease continuum, which always starts before admission to the intensive care unit (ICU), in the majority of cases even before hospital admission. Reflecting the common practice in many healthcare systems that critical care is mainly provided in the confined areas of an ICU, any delay in ICU admission of critically ill patients is associated with increased morbidity and mortality. However, if appropriate critical care interventions are provided before ICU admission, this association is not observed. Emergency critical care refers to critical care provided outside of the ICU. It encompasses the delivery of critical care interventions to and monitoring of patients at the place and time closest to the onset of critical illness as well as during transfer to the ICU. Thus, emergency critical care covers the most time-sensitive phase of critical illness and constitutes one missing link in the chain of survival of the critically ill patient. Emergency critical care is delivered whenever and wherever critical illness occurs such as in the pre-hospital setting, before and during inter-hospital transfers of critically ill patients, in the emergency department, in the operating theatres, and on hospital wards. By closing the management gap between onset of critical illness and ICU admission, emergency critical care improves patient safety and can avoid early deaths, reverse mild-to-moderate critical illness, avoid ICU admission, attenuate the severity of organ dysfunction, shorten ICU length of stay, and reduce short- and long-term mortality of critically ill patients. Future research is needed to identify effective models to implement emergency critical care systems in different healthcare systems.

Regional access to a centralized extracorporeal membrane oxygenation (ECMO) service in Victoria, Australia

Introduction

Victoria, Australia provides a centralised state ECMO service, supported by ambulance retrieval. Equity of access to this service has not been previously described.

Objective

Describe the characteristics of ECMO recipients and quantify geographical and socioeconomic influence on access.

Design

Retrospective observational study with spatial mapping.

Participants and setting

Adult (≥18 years) ECMO recipients from July 2016-June 2022. Data from administrative Victorian Admissions Episodes Database analysed in conjunction with Australian Urban Research Infrastructure Network population data and choropleth mapping. Presumed ECMO modes were inferred from cardiopulmonary bypass and pre-hospital cardiac arrest codes. Spatial autoregressive models including Moran's test used for spatial lag testing.

Outcomes

Demographics and outcomes of ECMO recipients; ECMO incidence by patient residence (Statistical-Area Level 2, SA-2) and Index of Relative Socioeconomic Advantage and Disadvantage (IRSAD); and ECMO utilisation adjusted for patient factors and linear distance from the central ECMO referral site.

Results

631 adults received ECMO over 6 years, after exclusion of paediatric (n = 242), duplicate (n = 135), and interstate or incomplete (n = 72) records. Mean age was 51.8 years, and 68.8 % were male. Overall ECMO incidence was 3.00 ± 3.95 per 105 population. 135 (21.4 %) were presumed VA-ECMO, 59 (9.3 %) presumed ECPR, and 437 (69.3 %) presumed VV-ECMO. Spatial lag was non-significant after adjusting for patient characteristics. Distance from the central referral site (dy/dx = 0.19, 95% CI -0.41-0.04, p = 0.105) and IRSAD score (dy/dx = 0.17, 95% CI -0.19-0.53, p = 0.359) did not predict ECMO utilisation.

Conclusion

Victorian ECMO incidence rates were low. We did not find evidence of inequity of access to ECMO irrespective of regional area or socioeconomic status.

Bridging the gap: safety and outcomes of intensivist-led ECMO retrievals

Purpose

Most extracorporeal membrane oxygenation (ECMO) cannulations are performed by cardiothoracic surgeons (CTS). Due to an increase in utilization of ECMO and limited availability of CTS, there is a mismatch between ECMO demand and CTS accessibility for remote cannulations. We report our intensivist-led program's experience in remote ECMO cannulations, retrievals, complications, and outcomes.

Materials and methods

A prospective, single-center, observational study was performed on patients that required ECMO cannulation at the referring facilities and were transported to our institution between program initiation, on October 1, 2014 to September 30, 2022. Results were presented as mean ± SD, median (min - max) or number (%).

Results

Since program commencement, 305 patients were accepted for ECMO retrieval. Three hundred and three patients were placed on ECMO at the 47 referring hospitals among 5 states. In our study, 185 (61%) patients required veno-arterial ECMO and 115 (38%) were placed on veno-venous ECMO. Three patients (1%) were cannulated for veno-arteriovenous ECMO. Twenty patients were cannulated under cardio-pulmonary resuscitation. Most of the patients were transported by ambulance (79%), 14% by helicopter, and 7% by airplane. Six out of the 303 patients did not leave the referring facility. All patients that left the referring hospitals arrived safely to our institution. No major complications occurred in route.

Conclusion

Our study's findings indicate that non-CTS physicians can successfully cannulate and retrieve patients with a low complication profile.

Retrieval of neonatal and paediatric patients on extracorporeal membrane oxygenation support in New South Wales, Australia

New South Wales has recently added the capability of extracorporeal membrane oxygenation to the neonatal and paediatric retrieval process and this paper describes the early experiences and protocol development for the first eight cases transported.

Patient Safety during ECMO Transportation: Single Center Experience and Literature Review

Background

Extracorporeal membrane oxygenation (ECMO) has been proven to support in lifesaving rescue therapy. The best outcomes can be achieved in high-volume ECMO centers with dedicated emergency transport teams.

Aim

The aim of this study was to analyze the safety of ECMO support during medical transfer on the basis of our experience developed on innovation cooperation and review of literature.

Methods

A retrospective analysis of our experience of all ECMO-supported patients transferred from regional hospital of the referential ECMO center between 2015 and 2020 was carried out. Special attention was paid to transportation-related mortality and morbidity. Moreover, a systematic review of the Medline, Embase, Cochrane, and Google Scholar databases was performed. It included the original papers published before the end of 2019.

Results

Twelve (5 women and 7 men) critically ill ECMO-supported patients with the median age of 33 years (2-63 years) were transferred to our ECMO center. In 92% (n = 11) of the cases venovenous and in 1 case, venoarterial supports were applied. The median transfer length was 45 km (5-200). There was no mortality during transfer and no serious adverse events occurred. Of note, the first ECMO-supported transfer had been proceeded by high-fidelity simulations. For our systematic review, 68 articles were found and 22 of them satisfied the search criteria. A total number of 2647 transfers were reported, mainly primary (90%) and as ground transportations (91.6%). A rate of adverse events ranged from 1% through 20% but notably only major complications were mentioned. The 4 deaths occurred during transport (mortality 0.15%).

Conclusions

Our experiences and literature review showed that transportation for ECMO patients done by experienced staff was associated with low mortality rate but life-threatening adverse events might occur. Translational simulation is an excellent probing technique to improve transportation safety.

Air Medical Transport of Patients Diagnosed With Confirmed Coronavirus Disease 2019 Infection Undergoing Extracorporeal Membrane Oxygenation: A Case Review and Lessons Learned

The coronavirus disease 2019 pandemic disrupted health care delivery in every respect, including critical care resources and the transport of patients requiring extracorporeal membrane oxygenation. Innovative solutions allowing for safe helicopter air transport of these critical patients is needed because extracorporeal membrane oxygenation resources are only available in specialty centers. We present a case demonstrating the interfacility collaboration of care for a patient with coronavirus disease 2019 infection and the lessons learned from the air transport. Careful planning, coordination, communication, and teamwork contributed to the safe transport of this patient and several others subsequently.

Venovenous ECMO treatment, outcomes, and complications in adults according to large case series: A systematic review

Background:

Venovenous extracorporeal membrane oxygenation (VV ECMO) has gained popularity for the treatment of refractory respiratory failure during and after the 2009 influenza pandemic, and still represents a precious therapeutic resource for severe novel coronavirus 2019 infection. However, most of the published studies are small case series, and only two randomized trials exist in literature.

Aim:

Aim of this systematic review is to describe trends in VV ECMO treatment outcomes according to large studies only.

Methods:

We searched and included studies with more than 100 VV ECMO cases dated up to August 1st, 2019.

Results:

Thirty-three studies published in the period 2011–2019 met inclusion criteria, for a total of 12,860 patients (age 46.3 ± 17.4 years). ARDS was mainly by pneumonia, in 3126 (37%) cases; further 401(7%) patients had H1N1 Influenza A infection. Cannulation-related complications occurred in 502 (7%) cases. Weighted mean (95% confidence interval) of VV ECMO duration was 8.9 (8.7–9.1) days, and ICU stay was 23.6 (22.4–24.8) days. Mortality at the longest follow up available was 40%. Data collection in 70% of the studies had a duration of >5 years.

Conclusion:

This study reveals the characteristics of large case VV ECMO studies.

ECMO Transport without Physicians or Additional Clinicians

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) has accelerated rapidly for patients in severe cardiac or respiratory failure. As a result, ECMO networks are being developed across the world using a "hub and spoke" model. Current guidelines call for all patients transported on ECMO to be accompanied by a physician during transport. However, as ECMO centers and networks grow, the increasing number of transports will be limited by this mandate.

OBJECTIVES

The aim of this study was to compare rates of adverse events occurring during transport of ECMO patients with and without an additional clinician, defined as a physician, nurse practitioner (NP), or physician assistant (PA).

METHODS

This is a retrospective cohort study of all adults transported while cannulated on ECMO from 2011-2018 via ground and air between 21 hospitals in the northeastern United States, comparing transports with and without additional clinicians. The primary outcome was the rate of major adverse events, and the secondary outcome was minor adverse events.

RESULTS

Over the seven-year study period, 93 patients on ECMO were transported. Twenty-three transports (24.7%) were accompanied by a physician or other additional clinician. Major adverse events occurred in 21.5% of all transports. There was no difference in the total rate of major adverse events between accompanied and unaccompanied transports (P = .91). Multivariate analysis did not demonstrate any parameter as being predictive of major adverse events.

CONCLUSIONS

In a retrospective cohort study of transports of ECMO patients, there was no association between the overall rate of major adverse events in transport and the accompaniment of an additional clinician. No variables were associated with major adverse events in either cohort.

Changes in Oxygen Saturation and Mean Arterial Pressure With Inhaled Epoprostenol in Transport

OBJECTIVE

Patients with hypoxemic respiratory failure have traditionally been considered one of the riskiest patient populations to transport, given the potential for desaturation with movement. We performed a retrospective cohort study to analyze our experience using inhaled epoprostenol in transport, with a primary objective of assessing change in the oxygen saturation throughout the transport.

METHODS

The transport records of patients with severe hypoxemic respiratory failure or right heart failure, transported on inhaled epoprostenol, were reviewed. The primary outcome was the change in SpO₂ from the start of the inhaled epoprostenol transport to the time of handover of care at the receiving institution. The secondary outcome was the change in the mean arterial pressure (MAP).

RESULTS

Comparing the initial SpO₂ to the final, there was no significant difference in oxygenation between time 0 and the transfer of care at the receiving hospital at 91% versus 93% (interquartile range [IQR] 86.0-93.5 vs 87.5-96.0, P = .49). Comparing the SpO₂ for those who had inhaled epoprostenol started by the transport team showed a larger change at 86% compared to 93% (IQR: 83.0-91.0 vs 86.5-94.5, P = .04). There was no change in the median MAP from time 0 to the end of the transport (77 vs 75 mm Hg, IQR, 67.5-84.8 vs 68.5-85.8, P = .70).

CONCLUSIONS

In this study, patients with severe cardiopulmonary compromise transported on inhaled epoprostenol had no significant change in their median oxygen saturations, with the overall population increasing from 91% to 93%. When inhaled epoprostenol was initiated by the transport team, the improvement was clinically and statistically significant with an increase in SpO₂ from 86% to 93%, with a final oxygen saturation comparable to those who were on the medication at the time of the team's arrival.

Extracorporeal Membrane Oxygenation in Transport Part 2: Complications and Troubleshooting

Factors taken for granted while the extracorporeal membrane oxygenation (ECMO) patient is maintained in a hospital setting can become critical when planning for transport. These issues include but are not limited to positioning of patients on a small transport stretcher, positioning of cannulas and equipment, ensuring adequate power sources and supply, inefficient temperature control, and a much higher risk of decannulation. It is paramount to be comfortable with the management strategies required to handle common complications of ECMO with limited resources in a relatively austere environment. Coagulopathy and bleeding are the most common complications occurring in up to 50% of ECMO patients. Loss of flow and hypotension from loss of volume or profound vasodilation after ECMO initiation need to be managed accordingly. Oxygenator malfunction can occur, and clinicians must be able to recognize the indicators of this complication promptly. Loss of pulsatility, low end-tidal carbon dioxide (ETCO₂), and differential hypoxia are common complications in venoarterial ECMO. In addition, an air embolism is life-threatening on venoarterial ECMO but may be better tolerated in the setting of venovenous ECMO. Recirculation in venovenous ECMO leads to circulation of poorly oxygenated blood and must be recognized and addressed. Lastly, pump failure, circuit rupture, and decannulation are devastating complications. Over the last decade, the use of extracorporeal membrane oxygenation (ECMO) has accelerated rapidly,^1-3 providing support for patients in severe respiratory or cardiac failure. With ongoing clinical experience and improvements in technology, the indications for ECMO are increasing.⁴ Many areas are developing centralized ECMO centers to serve their surrounding communities.^5-7 To use a centralized ECMO referral model, patients need access to effective, safe critical care transport, but transporting a patient on ECMO carries a significant risk of adverse events.^8-13 The purpose of this review is to highlight some of the most common adverse events in ECMO transports and provide management suggestions. Note that these recommendations are not a substitution for close collaboration with medical control, and all adverse events should be promptly reported per organizational protocols.

Extracorporeal Membrane Oxygenation in Transport Part 1: Extracorporeal Membrane Oxygenation Configurations and Physiology

Extracorporeal membrane oxygenation (ECMO), a term used to describe oxygenation that occurs outside of the body, is an increasingly common means of supporting the most critically ill patients. Because of the invasiveness and high probability of serious complications during ECMO, ECMO is typically indicated only when there is a high likelihood of death with conventional treatment. With continued improvements in technology and increasing clinical experience, transport clinicians are increasingly likely to be called on to transport patients on ECMO. ECMO can be initiated in 2 distinct forms, venovenous or venoarterial, and can primarily support the respiratory system or the cardiac and respiratory systems concurrently. This review will cover the basic physiology and components of ECMO as well as the preparation for ECMO transport for adults.