COVID-19 within a pandemic negatively influences today pregnant patients worldwide. Though at most of patients heavy disease is not noted, at some it nevertheless is shown. The purpose of this article — to formulate the actions for respiratory support recommended for the infected pregnant patients with a heavy acute respiratory syndrome of SARS-CoV-2.
Initial actions for the pregnant patients with hypoxemic respiratory insufficiency infected with COVID-19 – carrying out an oxygenotherapy. It can be done by means of a usual oxygen nasal cannula or a front mask. The current recommendations for nonpregnant patients assume the beginning of an oxygenotherapy with blood saturation level oxygen lower than 92% and strongly recommend this therapy at level below 90%. Based on physiological changes at pregnancy (for example, the increasing oxygen requirement and physiological increase of partial pressure of oxygen), it is offered to begin an oxygenotherapy for pregnant patients at blood saturation level with oxygen less than 94%. Therapy has to be titrated to avoid blood saturation level oxygen higher than 95%. As soon as oxygen supply is begun, obstetricians need to consult with the specialist on maintenance of passability of respiratory tracts (for example, with the anesthesiologist) whether the endotracheal intubation will be necessary is later. Together with an oxygenotherapy it is necessary to ask the patient to lay down on a stomach to improve oxygenation. The last can be considered for pregnant patients at terms less than 20 weeks.
High-line nasal cannula – a good alternative for treatment of patients with acute hypoxemic respiratory insufficiency whose state does not improve, despite a standard oxygenotherapy and who has no indications for an endotracheal intubation. Patients have to be hemodynamically stable and have free passability of respiratory tracts (a normality a soznniya, the expressed tussive reflex with an adequate otkhozhdeniye of a phlegm). The high-line nasal cannula in action is similar to a standard nasal cannula; however, the stream of oxygen can reach 60 l/min (air heats up and moistened). Oxygen concentration in the inhaled mix can also be titrated more precisely, than by means of a standard nasal cannula. Usually used initial parameters are a stream of 50-60 l/min with oxygen concentration in the inhaled mix 1.0 (100% oxygen). As soon as it is noted improvement, oxygen concentration in the inhaled mix it is necessary to lower before the stream decreases because the stream provides mobilization of alveoluses (high air flow leads to 3–5 cm of H2O of ventilation with positive pressure, keeping more alveoluses opened). Unlike noninvasive ventilation with positive pressure, the high-line nasal cannula, apparently, does not increase risk of transfer of a respiratory virus (including a coronavirus) in comparison with standard oxygen therapy. It made a high-line nasal cannula the main therapeutic option for patients with COVID-19.
Noninvasive ventilation with positive pressure is the one more method which is usually used for patients at whom at a standard oxygenotherapy improvements are not noted however a condition of which does not demand an intubation of a trachea and invasive mechanical ventilation. Noninvasive ventilation with positive pressure is ideal for patients with a cardiogenic fluid lungs or exacerbation of a chronic obstructive pulmonary disease with respiratory acidosis. Unlike a high-line nasal cannula, use of noninvasive ventilation with positive pressure can be connected with the increased risk of transfer of a disease to health workers because of its aerozoleobrazuyushchy properties. It does a high-line nasal cannula by the most suitable option for patients who are not helped by a standard oxygenotherapy and who do not need an endotracheal intubation yet. If resources are limited and the high-line nasal cannula is inaccessible, it is possible to consider the possibility of use of noninvasive ventilation with positive pressure.
Use of nebulayzerny drugs and also the drugs causing otkhozhdeny phlegms without emergency, has to be minimized at patients with COVID-19 infection as they increase risk of infection of health workers. If this treatment is necessary, it has to be carried out in the insulating room for patients with the infection which is transmitted in the airborne way, and all people in this room have to be completely equipped with individual protection equipment.