Transatlantic veno-venous ECMO bridge for lung transplantation

Abstract

This report details the challenging journey of a 58-year-old male with a progressive fibrotic lung disease who needed a lung transplantation (LTx). Residing on the remote island of St. Eustatius, access to specialized medical care was limited, but he was entitled to receive appropriate medical care in the Netherlands. Collaborative efforts among medical teams across the world resulted in a successful transatlantic transport of the patient on awake veno-venous extracorporeal membrane oxygenation (vv-ECMO) to the Netherlands. A successful LTx was performed without complications. This case shows that vv-ECMO flight transport, when conducted by an experienced team, is a safe procedure for highly selected lung transplant candidates.

Case

This case report presents the challenging journey of a 58-year-old male with sarcoidosis and progressive fibrotic lung disease since 2013 (Figure 1). Living on the small Dutch Caribbean island of St. Eustatius, he faced limited access to specialized medical care. In 2019, he presented with progressive fibrotic lung disease with a restrictive lung function and significant diffusion limitation. He was referred to a neighboring island, Sint Maarten, for further evaluation and had been managed with steroids and methotrexate. However, fibrosis progressed, which required long-term oxygen therapy at home. A Dutch pulmonary physician, temporarily assigned to Hospital Fundashon Mariadal in Bonaire as part of specialist medical care support from Amsterdam University Medical Center, was well-informed about the patient's critical condition and conducted frequent video consultations with the patient. He asked our lung transplant (LTx) team in Groningen, the Netherlands, if the patient could be a LTx candidate. Due to concerns about safe transport by plane and insufficient information about his cardiac function, we could not accept him for LTx. To obtain a comprehensive cardiac workup, the patient was transferred to Colombia (Medellin, Clinica CardioVID), where he underwent a coronary angiogram (CAG), cardiac ultrasound, computed tomography (CT) scan, and positron emission tomography (PET) scan (health insurance policies on St. Eustatius cover medical referrals to Colombia for medical examinations that cannot be performed on Sint Maarten or other islands of the Kingdom of the Netherlands). Upon returning to St. Eustatius, he experienced severe respiratory distress caused by a pneumothorax, necessitating the insertion of a chest tube. He was promptly transported to Sint Maarten since there was no pulmonary physician available on St. Eustatius to manage the pneumothorax. A chest drain was inserted by a surgeon on Sint Maarten. As there were no pulmonary physicians available on the islands, he was once again evacuated to Colombia by plane for pleurodesis (Medellin, Colombia, Clinica CardioVID, elevation above sea level 4,900 ft). At arrival, his oxygen levels were critically low, and he required 15 liter/min of oxygen by Venturi Mask in Colombia. CT scans, CAG, and cardiac ultrasound findings were sent to the University Medical Centre Groningen, and the patient was referred for LTx once again. Coronary disease was ruled out, and the PET scan showed no active sarcoidosis or malignancy. The CT scan indicated severe fibrosis with bullae and a pneumothorax (Figure 2), along with an ineffective chest drain placement, likely within a bulla. Right heart catheterization demonstrated pulmonary hypertension (Pulmonary artery pressure 70/30; Mean 43). He was accepted for bilateral LTx in the Netherlands, on the condition that safe transport could be arranged. Because he was accepted for a lung transplant, pleurodesis was no longer performed.

Figure 1.

At first the flight from St. Eustatius to St. Maarten. Thereafter, the 13-hour vv-ECMO flight from Medellin, Colombia, with a refueling stop in Canada, to Groningen, the Netherlands.

Figure 2.

CT scan of the patient showing fibrosis, bullae, and a pneumothorax.

Transport

At the time of the request for transport, the patient was hospitalized in the intensive care unit of Clinica CardioVID in Medellin, Colombia. A teleconference with the treating team in Medellin, the University Medical Centre Groningen, and the transport team was arranged to discuss options and limitations of a long-range air ambulance transport of the patient from Medellin, Colombia, to Groningen, the Netherlands for a possible LTx (great circle transport distance 5,550 miles). The option of transport by sea would take too long, given the condition of the patient. It would also be less safe. Air transport was planned using a Bombardier Challenger 604, with a 2-sector flight plan (Medellin – Halifax, flight time 05:55 hour; refuelling 00:45 hour, Halifax – Groningen, flight time 06:05 hour). During aeromedical transport at 41,000 to 49,000 ft, patients experience a reduction in cabin pressure, which leads to a linear decrease in arterial oxygen pressure (PaO₂) unless the fraction of inspired oxygen is increased. Changes in cabin pressure can be avoided if the cruising altitude is restricted to 25,000 ft, allowing the cabin to be pressurized to sea level (760 mm Hg). However, in this case, a sea-level cabin pressure was not deemed necessary because the patient was already at an elevation of 4,900 ft in Medellin, and it was not feasible due to the long overall distance (lower flight levels significantly increase aircraft fuel consumption, requiring additional refueling stops).

Although the patient did not oxygenate well, before transport, with an arterial PaO₂ of 46 mm Hg despite 15 liter/min via a venturi mask, intubation, and positive pressure ventilation appeared to carry excessive risks due to the severely fibrosed lung with pulmonary hypertension, a pneumothorax, and extensive bullae in both lungs. After considering the risk-benefit balance of all available options, cannulation for veno-venous extracorporeal membrane oxygenation (vv-ECMO) in an awake patient was considered the most favourable option. The patient was cannulated in a femoral-jugular configuration by the Clinica CardioVID team the day before transport. On the day of transfer, the transport team (2 physicians and a flight nurse) switched the vv-ECMO to a Getinge/Maquet Cardiohelp console (Cardiohelp, Getinge, Göteborg, Sweden). A second system was kept on standby as a backup during transport. The vv-ECMO was run with a sufficiently high blood flow rate of 3.5 liters/min, ensuring adequate oxygenation and reduced interference from pressure alarms. Additionally, the high blood flow minimizes the need for extensive anticoagulation of the patient. Blood gas analysis, ACT, and INR/PT testing capabilities were available in-flight via an ISTAT PoC device (iSTAT, Abbott Point of Care, Chicago IL). A minimal sweep gas flow of 1 to 2 liter/min 100% oxygen was used to ensure spontaneous breathing. Blood gas analysis was used regularly to optimize vv-ECMO settings. At a cabin pressure equal to 6,000 ft above sea level, PaO₂ was recorded at 60 mm Hg and PaCO₂ at 47 mm Hg. Automated continuous monitoring of electrocardiogram, SpO2, arterial blood pressure, and respiratory rate was used. Ultrasound with linear scan probe and color Doppler was available to check and adjust vascular access if needed (Butterfly IQ+, Butterfly Network, Burlington, MA). The patient was transported in a supine position (self-mobilisation) with elevated head rest, in good mood throughout the flight (Figure 3). The transport was carried out without complications or equipment failure, and the patient arrived well at Groningen, after a 13-hour transport on awake vv-ECMO.

Figure 3.

Patient awake on for veno-venous extracorporeal membrane oxygenation (vv-ECMO) for transport.

Transplantation

In Groningen, the patient was admitted to the intensive care unit with vv-ECMO.

Vv-ECMO support was initiated solely to facilitate transport. Additionally, it can take weeks for donor lungs to become available, and the use of ECMO is known to carry significant risks and complications. Therefore, the vv-ECMO support was discontinued on the same day of arrival, and the cannulas were removed. Subsequently, the patient was placed on high flow nasal oxygen therapy with a flow rate of 30 liter/min and an fraction of inspired oxygen of 65%. The patient was listed for LTx, with a high Lung Allocation Score. Fortunately, a suitable lung offer was received shortly after, and the LTx was successfully performed the following day without any complications. In the postoperative period, the patient experienced acute kidney injury that resolved within a few days. Additionally, he encountered difficulties in expectorating sputum, partly attributed to a right-sided diaphragm paresis. After 1 week, he was able to be extubated and subsequently transferred to the pulmonary ward for further care. After 6 weeks of hospitalization in the Netherlands, the patient was discharged. Being a Dutch citizen with appropriate insurance coverage, he was able to secure his own apartment. Family and friends from both St. Eustatius and the Netherlands came to visit him during this time. Currently, the patient's clinical condition is still moving forward, with ongoing improvement in lung function (Figure 4). One year after LTx, a joint decision will be made between the patient and health care providers to determine whether it is safe for him to return to St. Eustatius. Regular video call conversations will be conducted for check-ups and monitoring.

Figure 4.

Lung function before and after lung transplantation. FEV1, forced expiratory volume in 1 second; FVC, forced vital capacity, LTx, lung transplantation.

Discussion

This unique case report demonstrates the safety and feasibility of vv-ECMO transportation during a 13-hour flight for a high-risk LTx candidate without the need for intubation and sedation. Our findings are consistent with a systematic review conducted by Yao et al, which included 647 ECMO cases, however, most of those covering transport distances of less than 1000 miles (regional transports).¹ Although few complications during transport were reported in the literature, some instances of hemodynamic instability and bleeding were attributed to deficiencies in medical team knowledge. Hence, the involvement of experienced staff and thorough preparation prior to transport are crucial.² Moving a critically ill patient out of an intensive care unit into a resource limited environment, such as an air ambulance, always involves risks. These risks can be mitigated to some extend by meticulous preparation, coordination, active case management, and experienced and well equipped teams, as we have described elsewhere.³ Nevertheless, transport risk needs to be counterbalanced by a tangible patient benefit, which in this case was access to LTx that was not available locally.

It is important to note that international air ambulance transportation, specifically those involving ECMO incurs significant costs up to 250,000 USD, depending on the distance and type of aircraft used. Therefore, this procedure should be reserved for highly selected patients. In the present case, the patient resides on a Dutch island and, being a Dutch citizen, is entitled to receive appropriate medical care in the Netherlands. The BES health care insurance, which covers medical expenses in Bonaire, St. Eustatius, and Saba, includes the cost of air transport to the Netherlands. It also covers the patient's stay in the Netherlands for up to a year after the transplant. However, given the high costs associated with the ECMO flight, as well as the subsequent LTx care and extended stay in the Netherlands, it is crucial to carefully select suitable candidates for this procedure. Selection criteria should encompass not only the patient's suitability for lung transplantation and their likelihood of surviving the flight but also their willingness to immigrate to the Netherlands and leave behind friends and family. A comprehensive decision-making process involving the referral center, transplant center, ECMO team, social work, and insurance providers is necessary to arrive at an appropriate decision. In this particular case, the patient had previously resided in the Netherlands and had 2 sons living there. His strong motivation to undergo transplantation, along with a high position on the waiting list (due to severe lung disease), made him a suitable candidate for lung transplantation (Table 1).

Table 1.

Lung Function Test Before and After Lung Transplantation

	Before LTx	25 days after LTx	4 weeks after LTx	8 weeks after LTx	10 weeks after LTx
FEV1, liter (%)	1.16 (37)	1.11 (33)	1.36 (41)	1.37 (41)	2.15 (65)
FVC, liter (%)	1.29 (33)	1.44 (34)	1.94 (46)	1.87 (44)	2.98 (71)

FEV1, forced expiratory volume in 1 second; FVC, forced vital capacity, LTx, lung transplantation.

In conclusion, vv-ECMO flight transport, when conducted by an experienced team, is a safe procedure for highly selected lung transplant candidates.

Disclosure statement

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgments: None.

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.