COVID–19呼吸不全に対して3本目のカニューレを用いたVV–V ECMO管理(Role of triple cannulation venovenous extracorporeal membrane oxygenation in patients with coronavirus disease)

(Mamiko Naito), 内藤 麻巳子; (Kota Hoshino), 星野 耕大; (Megumi Koie), 鯉江 めぐみ; (Hiroko Ohkura), 大藏 裕子; (Hiroki Hatomoto), 鳩本 広樹; (Shintaro Yamasaki), 山崎 慎太郎; (Hiroyasu Ishikura), 石倉 宏恭

A 32–year–old man with dry cough was admitted to a hospital for suspected coronavirus disease–induced pneumonia. The SARS–CoV–2 PCR test showed positive results on day 3 after symptom onset. Mechanical ventilation and venovenous extracorporeal membrane oxygenation (VV ECMO) were initiated for respiratory function deterioration on day 8 after symptom onset. However, ECMO did not maintain adequate oxygenation, and ventilator settings did not allow lung rest. Therefore, secondary ECMO transport was performed, and the patient was transferred to our center via ECMOnet. The reduced oxygenation level was attributed to the use of a small drainage cannula with consequently reduced ECMO circulation. Replacement of the small drainage cannula was unsafe; therefore, an additional drainage cannula was inserted, and the ECMO configuration was switched to VV–V ECMO, which established sufficient ECMO circulation and improved his oxygenation levels, and ventilator settings were modified for lung rest. He was weaned off ECMO on day 14, and retransferred to the previous hospital on day 21 after symptom onset. Selection of a drainage cannula of optimal size is important in patients who receive VV ECMO support. Conversion of a VV ECMO to VV–V ECMO configuration is useful in cases of insufficient ECMO blood flow.