ABSTRACT
Introduction: Dual-lumen cannula is used for extracorporeal membrane perfusion (ECMO) to support patients with ARDS due to COVID-19 as a bridge to lung recovery. It tends to be a longer support and there are several factors that can degrade the physical structure of the ECMO cannula and put the cannula at risk for breakage. Case Report: A 63-year-old woman was admitted to the hospital with COVID-19 pneumonia. Two days later, she was intubated and VV-ECMO was initiated due to treatment-resistant acute respiratory failure;a 28Fr CrescentTM dual-lumen cannula (Medtronic, MN) was inserted through the left subclavian vein and connected to a centrifugal oxygen pump with a centrifugal oxygenator. Within six weeks after onset, the patient was unable to be weaned from the ventilator and was transferred to our center with ECMO connected for consideration of lung transplantation. Two days after transfer, the patient developed acute aphasia, altered mental status, disturbed consciousness, and left arm seizures. A suction sound was heard from the left subclavian cannula insertion site and the ECMO bubble detector alarmed, but local inspection, chest X-rays, and CT scans of the brain and chest showed no obvious abnormalities. The patient was reintubated for encephalopathy and subsequently underwent a tracheostomy. The patient regained normal neurological function over the next 7 days. However, the air bubble sensor alarmed and suction sound was heard at the cannulation site again, and air bubbles were seen in the oxygenator. Due to concerns about air entrapment and cannula failure, we changed to a dual-canal VV-ECMO configuration using a right internal cervical and a left femoral cannula. The removed cannula had a 2 cm fracture distal to the skin insertion site. After resumption of ECMO, no new neurological episodes occurred. While awaiting lung transplantation, the patient died due to sepsis and multiple organ failure. An autopsy revealed a possible cause of cerebrovascular disease patent foramen ovale and air embolism to the brain. If a patient has been on ECMO for a long time and the bubble sensor warns of air detection, cannula breakage and impending air embolism should be suspected clinically, even if the defect is not found on examination and is not evident on imaging. If the COVID-19 epidemic continues, increased transport events may increase ECMO cannula breakage.
ABSTRACT
Rationale: Coronavirus disease 2019 (COVID-19) can cause severe respiratory failure that worsens despite maximal medical management. When to initiate extracorporeal membrane oxygenation (ECMO) and how to manage these patients on ECMO is not clear. Here, we present our experience with venovenous ECMO to support patients with COVID-19 and compare it to historic patients supported with VV-ECMO for other causes of respiratory failure. Methods: Patients admitted to our tertiary academic medical center in 2019 and 2020 who received VV ECMO support were included in this retrospective chart review. We examined patients with and without COVID-19 infection. We placed COVID-19 patients on ECMO who failed supportive care with mechanical ventilation using a high PEEP low tidal volume strategy, prone positioning, and neuromuscular blockade. Data analysis were done in Excel and Prism. Non-parametric data were compared with unpaired, two-tailed Mann-Whitney tests. Results: ECMO was provided to 26 COVID-19 patients and 38 patients without COVID-19. Median (interquartile range) age of COVID-19 patients was 49.5 (40.5-56.25), compared with non-COVID-19 patients: 53.5 (30.5-60.25), p=0.28. COVID-19 patients had a significantly higher BMI: 32 (30.1-35.9) vs. 26.4 (23.6-29.4), p<0.001. There were 27% female COVID-19 patients compared with 37% female non-COVID patients (p=0.43). COVID-19 patients had similar PaO2:FiO2 ratios as non-COVID patients on day of cannulation: 74 (69-112) vs 78 (60-205), p=0.65. COVID-19 patients had longer ventilator duration pre-cannulation (not including time spent intubated at outside hospitals prior to transfer to our center)-1.9 (1.4-7.0) days vs 0.7 (-.2-1.0) days, p<0.001. COVID patients spent more days on ECMO compared with non-COVID patients: 20.7 (7.3-36.5) vs. 11.5 (3.8-26.8), p=0.14. Twelve (46%) of the COVID-19 ECMO patients died, compared with 9 (25%) of the non-COVID ECMO patients, p=0.10. Conclusions: In patients with severe SARS-CoV-2 pneumonia induced ARDS who fail maximal supportive therapy with mechanical ventilation, outcomes are similar or worse than patients historically receiving VV ECMO support for respiratory failure. These findings highlight the need to determine the optimal timing of ECMO initiation and management in patients with severe SARS-CoV-2 pneumonia.