The coronavirus-induced disease 2019 (COVID-19) is characterized by a wide range of the clinical options of a current varying from asymptomatic virus colonization to the acute respiratory distress syndrome (ARDS) demanding an intubation and the difficult strategy of the artificial ventilation of the lungs (AVL). In cases of extremely heavy respiratory insufficiency which is not allowing to provide adequate gas exchange despite optimization of maintaining the patient and the IVL optimum parameters, veno-venous extracorporal membrane oxygenation (VV EKMO) can become an additional option of a maintenance therapy in a limited arsenal of means against COVID-19. Already plays the same role of EKMO in treatment of other heavy viral respiratory infections, such as flu H1N1 and relevant recommendations support use of EKMO at COVID-19.
Results of autopsy demonstrate that the pathogeny of respiratory insufficiency at COVID-19 has similarity to ORDS pathogeny. Diffusion injury of alveoluses with filling of a gleam of alveoluses with liquid and formation of hyaline membranes is noted that leads to decrease in a komplayns of lungs and an anoxemia which can be rather expressed. EKMO can be shown to patients with heavy disorders of oxygenation (threshold value of the P/F index about 80-100) against the background of respiratory insufficiency which is characterized by either the periods of long desaturation, or increase in pressure in respiratory tracts, despite optimization of parameters of ventilation. EKMO is not considered until it becomes clear that further carrying out IVL in the safe mode is not possible, despite optimization of parameters of ventilation and attempt to turn the patient to position on a stomach. There are several options of absolute contraindications to connection of EKMO for patients with COVID-19: age more than 60 years, multiorgan insufficiency, the active malignant disease existing chronic cordial, pulmonary (not including bronchial asthma) a disease or pathology of a liver, the unknown or uncertain neurologic status and a heavy neutropenia. The Body Mass Index (BMI)> 35 kg/sq.m is considered by a number of authors as a relative contraindication, taking into account fears for technical support and achievement of adequate streams of veno-venous EKMO in the conditions of a gross obesity. Other relative contraindications according to authors: active bleeding, chronic renal dysfunction, immunosuppression and the accompanying infection with multiresistant flora.
Strategy of a kanyulyation has to be developed for the purpose of the maximum increase in efficiency to exclude an unjustified expense of the limited individual protection equipment (IPE), protecting at the same time personnel from infection and to minimize time of stay of patients in a condition of an anoxemia. Considering that the emergency procedures inevitably are followed by higher risk of mistakes and the subsequent contact of team of a kanyulyation with COVID-19, it makes sense to organize screening of patients in ORIT for identification of candidates by whom vascular access for connection of EKMO can be required. To such patients are preventively catheterized the right internal jugular and femoral vein with installation of introdyyuser (against the background of the coming pronirovaniye stage) that allows to avoid a critical stage of ensuring vascular access in case of need of connection of EKMO. The number of health workers in chamber during the procedures of a kanyulyation has to be minimum necessary. The additional personnel can be in expectation, but outside chamber, ready to come to the rescue in case of clinical need. It is important that all potential members of the team of EKMO completed the corresponding courses and also personal trainings on appropriate use of SIZ.
The main objective of veno-venous EKMO consists in providing respiratory support to the patient while his lungs are restored after the cellular cytotoxic damage mediated SARS-CoV2 that allows to use the IVL ultraprotective modes. In the absence of problems with bleeding therapeutic anti-coagulation is standardly used. Patients during functioning of EKMO, as a rule, are in a condition of sedation with obligatory monitoring of the neurologic status. Protective IVL is carried out. In process of restoration of functioning of lungs of the patient, the attempt of decannulation is preceded by a trial stop of supply of gas on the device EKMO. If there are signs that support is not required any more, anti-coagulation stops and the EKMO system is removed with decannulation in chamber. The hemostasis is provided with the strengthened compressing seams and a manual compression. After decannulation patients gradually leave from the fan.