VOLUME

   Since November 2014, Bangkok Hospital has transported 3 patients with ECMO support. The first patient was a 20-year-old female. She was diagnosed with acute viral myocarditis at Chiangmai. After presenting with fever for 7 days, progressive dyspnea developed, and she was admitted to Maharaj Nakorn Chiangmai Hospital, Chiangmai University. The heart failure worsened and an intra-aortic balloon pump (IABP) was inserted to support the heart function. The patient’s vital signs were unstable therefore VA-ECMO was established with the right femoral artery and right femoral vein cannulation. IABP was then removed once vital signs were stable. At this point, Bangkok Hospital was consulted to receive the patient. On the 3^rd day with ECMO support, the Bangkok Hospital ECMO transport team, consisting of a surgeon, anesthesiologist, perfusionist and three aviation team members, flew to Chiangmai on a charter flight. By this time, the patient’s condition had improved. She was awake and communicated well under a low dose of sedation and low dose of inotropic drugs. Then the ECMO team changed the ECMO machine and circuit from Rotaflow® to Cardiohelp® as it is more compact for transportation, taking about three hours to change and stabilize the patient. The patient was then taken to Chiangmai International Airport by ambulance, which took around 30 minutes, then switched to the jet flying to Don Mueang International Airport, which took around 90 minutes, and finally the patient was transferred to an ambulance to go to Bangkok Heart Hospital (BHT), which took around 40 minutes. There were no catastrophic events during transportation (Figure 2). ECMO was removed after 7 days at BHT, and both the right femoral artery and the right femoral vein were repaired. Two days after ECMO was removed, her right leg was swollen but not tender. Doppler ultrasound confirmed the diagnosis of deep vein thrombosis at the right femoral vein. The patient was advised to take Warfarin for this condition. The patient returned to her country of origin 5 days after ECMO was removed, escorted by a doctor.

Figure 1: Type of ECMO; (1) Veno-Arterial (VA) ECMO, (2) Veno-Venous (VV) ECMO (Cardiohelp®, Maquet).

   The second patient was a 41-year-old male. He had suffered multiple traumas from an accident and was admitted to Bangkok Trad Hospital. Multiple ribs fractures with severe pulmonary contusion and pulmonary hemorrhage progressed to severe respiratory distress syndrome that could not be supported with a high setting ventilator. On the 5^th day after the accident, Bangkok Hospital was consulted to receive this case. The Bangkok Hospital ECMO transport team, consisting of a surgeon, anesthesiologist, perfusionist and a critical care nurse, was assembled. At the referring hospital, non-heparinized VV-ECMO was established at the jugular vein and right femoral vein cannulation and the patient was stabilized for about 3 hours. The patient was taken to BHT by ground ambulance which took around 5 hours. The patient was stable during transportation. On the 3^rd day after ECMO insertion, ECMO failed to maintain flow due to a clot in both the inflow and outflow cannula. The ECMO circuit was changed and a left femoral vein cannulation was added. Unfortunately, the patient died after changing the circuit due to prolonged hypoxemia.

   The third patient was a 70-year-old male. He was diagnosed with severe triple vessels disease and received an off-pump coronary artery bypass graft at Bangkok Hospital Pattaya. On the 2^nd day after the operation, the patient developed high grade fever and hypoxemia. Although the high setting ventilator was adjusted the oxygen saturation remained about 80%. On postoperative day 3, Bangkok Hospital was consulted to receive this case. He was diagnosed sepsis. The Bangkok Hospital ECMO transport team, consisting of a surgeon, anesthesiologist, perfusionist and a critical care nurse, was assembled. At the referring hospital, VV-ECMO was established at the right jugular vein and right femoral vein cannulation. The patient was stabilized for about 3 hours. The patient was then taken to BHT by ground ambulance, which took about 2 hours. He was stable during transportation (Figure 3). On the 3^rd day after ECMO insertion, oxygenation returned to acceptable levels, no fever presented, and his white blood cell count decreased so ECMO was removed. One day after removing ECMO, his right leg was swollen with no tenderness. Doppler ultrasound was performed to confirm a clot in the right femoral vein, and right popliteal vein. Heparin and warfarin was used to treat deep venous thrombosis. The patient was transferred back to Bangkok Hospital Pattaya on day 5 after ECMO insertion.

Figure 2: Patient with Transport ECMO (Cardiohelp®, Maquet).

Figure 3: Ground transportation.

Table : Case Transportation with ECMO.

   The transport of three patients from referring hospitals to Bangkok Hospital was done safely, either by establishing or changing ECMO at the referring hospital or during transportation of the patient. Two patients recovered after arriving at Bangkok Hospital. ECMO was removed but they both developed deep vein thrombosis in the leg. One patient had an open cut to insert the cannula followed by an open repair. The Seldinger technique was used for another patient then removed and compressed. Both patients took heparin and warfarin so their leg improved from swelling without catastrophic events. Zangrillo’s group⁶ demonstrated that EMCO is still associated with some difficulties in the clinical outcomes. It was found that 10 percent of patients suffered from venous thrombosis faced complications. However, there was no evidence from this systemic review suggesting whether venous thrombosis occur between using of ECMO or after removal of cannula. In addition to this, there were no guidelines or recommendations for the prevention of venous thrombosis after removal of cannula. Further investigations should be conducted to identify incidences of venous thrombosis after removal of cannula and prevention.

   Unfortunately one patient died from cannula thrombosis due to multiple trauma, cerebral hemorrhage and pulmonary hemorrhage which could not be heparinized. Reviewed literatures from 2007-2012 by Pei-Hung’s group⁷ reported that 22 multiple injury patients received nonheparinized ECMO and mortality rate is about 18% (4 case). In our case, patient died from prolong hypoxemia after thrombosis of cannulas and circuit. Early detection would help preventing such problems.

   Bangkok Hospital team is the first transported ECMO team in Thailand and we perform this procedure with good results as at other ECMO centers.^8-10 The successful transportation of ECMO patients requires a skilled Transport Medical Director who is responsible for planning the mission, preparing and assembling the transport team. Furthermore, the ECMO transport team should receive the requisite training.