Page 34 - ANZCP Gazette APRIL 2022

VV ECMO SUPPORT FOR RESPIRATORY FAILURE SECONDARY TO COVID PNEUMONITIS*
Ray Miraziz CCP, FANZCP Westmead Hospital
Early 2020 Westmead Hospital was assigned as the principal referral centre for Covid-19 outbreak for Western Sydney. During this period, Coronavirus case numbers remained low, and intensive care beds occupancy did not exceed their capacity. Westmead treated one patient for respiratory failure secondary to covid pneumonitis on veno-venous ECMO. This was the first patient to be supported on VV-ECMO in Australia for this disease.
Unfortunately, our current situation (Sept 2021) is of total opposite, our ICU consist of 44 beds which are currently all occupied with 34 covid positive patients, 11 are ventilated and 2 are supported by VV ECMO.
Our first case is a 49-year-old male 105Kg who was referred to ECMO after 6 days in ICU, for persistent severe hypoxia secondary to covid pneumonitis. Currently 24 days on VV ECMO support, requiring higher than usual sweep rates of 8-10 L/min, at pump flows of 4-5 Litres to achieve SpO2 above 90%.
Our second patient is a 58 y/o male, 86 Kg was referred to ECMO on the day of arrival due to respiratory arrest and profound hypoxia secondary to covid pneumonitis. He has been supported for 3 days and is responding well.
On the afternoon of the ANZCP Webinar on COVID 19 and ECMO, we were advised a 40-year-old male, 180Kg, 7 days in ICU, intubated with persistent profound hypoxaemia was placed on high flow VV ECMO as proning presented difficult.
To discuss our challenges and experience with Australia’s first covid case supported with VV-ECMO following type 1 respiratory failure secondary to COVID-19 pneumonitis, was in March 2020. Her treatment during prolonged hospitalisation was complicated by significant airway bleed and the inability to mechanically ventilate, resulting in ECMO support and to prone while on ECMO. Throughout her care we were challenged with PPE shortage, membrane change-out, proning, patient transfer to imaging department for CT scan , Acute renal failure & multiorgan failure requiring dialysis and hypercalcaemia. Despite these challenges she was successfully decannulated after 42 days on ECMO and discharged from ICU after 81 days and left the hospital after 107 days. She had a total weight loss of approximately 12Kg after her diagnosis of Covid -19.
Our patient, a 55-year-old, 151cm, 61Kg female, non-smoker, returning traveller from the Philippines with past medical history of mild asthma, sleep apnoea and type 2 diabetes mellitus, presented at Mount Druitt hospital in Syd¬ney, with increasing lethargy and fevers up to 42 degrees C. Her
diabetic condition has been well controlled with prescribed oral hypoglycaemics Otherwise relatively healthy.
Nasopharyngeal swabs obtained at the time of hospital presentation were positive by PCR for SARS-Cov-2. She was transferred to Westmead for treatment. A Chest CT scan indicated bilateral patchy air space infiltrate with scattered ground glass density and subpleural confluent consolidation, consistent with a diagnosis of COVID -19.
On Days 4-9 of hospitalisation, her respiratory status deteriorated, and she was transferred to ICU for intubation and lung protective ventilation. Her metabolic status continued to deteriorate despite a high PEEP ventilator setting. Proning was considered during this period, however ruled out due to her abdominal adiposity. She was then referred for ECMO.
On day 10 of her admission, ECMO Cannulation was carried out via a femerofemoral approach using a 23 French Maquet access and 21 French Maquet return cannulae. At the time of cannulation, Transesophageal echocardiography (TOE) revealed a thrombus had transitioned through the right atrium. This was treated with Clexane for Venous thromboembolism (VTE) prophylaxis. there was an immediate improvement in patient’s haemodynamic and right ventricular function.
On days 11-14 on VV-ECMO, her airway bleed was leading to a complete proximal airway occlusion. Heparin infusion was ceased and treated with nebulised Tranexamic acid (TXA). Thrombus removal was successful following bronchoscopy.
By days 17-18 on VV-ECMO, her airway bleed had stabilised, prone ventilation was commenced aiming to facilitate ongoing lung recruit¬ment. By the fifth cycle, a chest X-ray demonstrated an improve¬ment in the aeration of lung fields.
Scheduled proning was a challenge due to staff availability. A total of 8 staff members per prone were required. This was repeated twice a day for almost 10 days.
Full PPE is a requirement when attending to all covid patients (Photo 1), Communication between team members while attending her care was also difficult in this gear.
Around this period our hospital P2/N95 mask and PPE shortages were due to all the mandatory Mask fitting and correct practice of Doning and Doffing. Some staff resorted to making their own face shields by securing the plastic shields on sweat bands (Photos 2)
By day 23 on VV ECMO, our patient developed persistently high calcium levels. Blood parathyroid and thyroid hormones
31 APRIL 2022 | www.anzcp.org