A 53-year-old man was admitted to our hospital, experiencing 11 days of cough, sputum, and 9 days of fever. His chest X-ray indicated ground-glass opacitie appears in the lower of right lung (Fig. 1A). SARS-CoV-2 was confirmed by the real-time reverse transcription–polymerase chain reaction (RT-PCR) assay and the nasopharyngeal specimen was positive. The patient was given NFHC, Arbidol, Lopinavir + Ritonavir, and Methylprednisolone (40 mg/d*8d).
After 12 days of treatment, he developed respiratory failure, with partial pressure of oxygen/ fraction of inspiration O2(PaO2/FiO2) < 150 mmHg for 12 hours and respiratory rate > 30/min over 6 hours, showing that the patient satisfied the sign of mechanical ventilation and was admitted to intensive care unit (ICU) for treatment. A chest X-ray showed that the density of lower lungs lobe increased, with spread plaque image and blur border (Fig. 1B). Over the next 96 hours, lung protective strategies and a restrictive fluid strategy were applied, but the patient got worse, with terrible lung compliance, hypoxemia, as well as the dense opacification of diffuse lesion in lungs (Fig. 1C). PPV was adopted, together with sedative and analgesic drugs, muscle relaxant, lung recruitment and phlegm drainage, but there was no significant improvement for the patient.
After 12 days of mechanical ventilation, the tracheotomy was performed for the patient, but his virus was still positive by detecting. The patient’s PaO2/FiO2 dropped to 80 and lasted for 24 h, which conformed to the implementing standard of ECMO. The patient was given ECMO treatment in the 16th day of mechanical ventilation. In terms of the initiation parameter of ECMO, the mode is V-V, the location of intubation is in the left femoral vein and right internal jugular vein, and the size of tube is 16f and 22 f. A chest X-ray showed that the catheter was in a reasonable position and the pulmonary lesions were aggravated (Fig. 1D).
During running time, activated partial thromboplastin time(APTT)was maintained 40–60 sec. The ECMO system was set to blood flow of 3.5-4.0 L/min and a sweep flow rate of 4.0–7.0 L/min, which was adjusted according to the PaCO2 obtained by blood gas analysis. The target coagulation profile was monitored by detecting the levels of APTT. During ECMO therapy, the target oxygenation was a normal PaCO2 and PaO2.
With the support of ECMO, haemolysis occurred, with plasma-free hemoglobin༞120 mg/dL. In addition, enterococcus faecalis led to infectious shock and unstable blood volume, but there was no any improvement after the adequate fluid resuscitation. ECMO catheter was replaced with right femoral vein and left internal jugular vein and the size of tubes was 19f or 22 f. Then the blood flow of ECMO got better, and haemolysis and infectious shock were controlled.
The re-examination of CT illustrated lesions in both lungs and severe exudation (Fig. 2, 1A-2A). At the early stage of ECMO, PPV was also carried out at the same time. The specific method of implementation: four nurses helped the patient turn over, one nurse checked the ECMO regularly and respiratory physician was responsible for the management and protection of the intubation. One doctor ensured the stability and flowing of the ECMO tubes, in case of pressure sores, so some materials were placed between skin and bed, and skin and tube to prevent pressure sores and bandage was applied to fix the tube of ECMO.
During the operation of ECMO (12 h/d), the ventilator mode setting was BIPAP, 26–30 cmH2O PIP, 6-8cmH2O PEEP and 18–25 rpm RR. The parameters of PPV: PEEP was down- regulated 2cmH2O and 22-26PIP, but other parameters kept steady. Except prone position, other care bundles were also taken, including hand washing, closed endotracheal suction, and appropriate sedation to assist the improvement (Fig. 2, 1B-2B). At the 17th day after ECMO initiation, exhaled tidal volumes were increased to 6 mL/kg and chest radiographs showed that lung effusion improved, after which the combination of awake ECMO and other comprehensive on bed and floor rehabilitation exercises were adopted.
The patient did the rehabilitation on bed and ground. Bending arms and lowing legs were bed exercises. He also sat on the side of bed for 30 minutes every day and accepted passive functional exercise for legs. Later, his standing position was also trained. After the patient was sent to ICU, he was given nutrition through jejunal nutrient canal, aiming at 25–30 kcal/kg and gradually increased the volume of eating food every time. Nucleic acid test of SARS-CoV-2 virus became negative 3 days after ECMO application. In the 27th day of ECMO support, with improved chest CT scan (Fig. 2, 1C-2C), the patient got rid of V-V ECMO. During the period of therapy, the parameters of mechanical ventilator and blood gas analysis were monitored (Fig. 3). In the 9th day of removal, the man was successfully closed casing. After a 4-day high flow nasal cannula oxygen therapy, he was transferred to the rehabilitation department.