[Artificial ventilation in patients with stroke: main results of the Russian multicenter observational clinical trial RETAS].

Objective: To analyze the relationship between the characteristics of respiratory support (RS) for patients with stroke and clinical factors with the number and structure of complications, deaths, and length of stay in the intensive care unit (ICU) and duration of artificial pulmonary ventilation (ALV).
Material and Methods: The Russian multicenter observational clinical study «Respiratory Therapy for Acute Stroke» (RETAS) that enrolled 1289 patients with stroke requiring RS was conducted under the auspices of the All-Russian public organization «Federation of Anesthesiologists and Resuscitators». Indications for ALV, the use of hyperventilation, the maximum level of positive end-expiratory pressure, starting modes of mechanical ventilation, timing of tracheostomy, the incidence of protein-energy malnutrition (PEM) and infectious complications were analyzed. The following scales were used to assess the severity of the condition: the National Institutes of Health Stroke Severity Scale (NIHSS), the Glasgow Coma Scale, the Glasgow Outcome Scale (GOS).
Results: For the group of patients with a stroke severity of more than 20 NIHSS points, the mortality increase was associated with initial hypoxia ( p =0.004), hyperventilation used to relieve intracranial hypertension ( p =0.034), and starting ventilation with volume control (VC) compared with starting pressure-controlled ventilation (PC) ( p <0.001). We found that the use of the instrumental monitoring of intracranial pressure was associated with a decrease in mortality ( p <0.001). The absence of PEM in patients with stroke is associated with a higher probability of a positive outcome (GOS 4 and 5) for the group with NIHSS less than 14 points ( p <0.001). Ventilator-associated tracheobronchitis and ventilator-associated pneumonia were associated with an increase in the duration of ALV, the duration of weaning from the ventilator (for ventilator-associated tracheobronchitis) and the duration of stay in the ICU, and also reduced the chances of favorable outcomes ( p <0.05).
Conclusion: The factors associated with increased mortality in acute stroke are: hypoxemia at the start of ALV, hyperventilation, starting ventilation with VC in comparison with starting ventilation with PC, the use of only clinical methods of monitoring intracranial pressure in comparison with instrumental monitoring. The adverse effect of PEM and infectious complications on the outcome in patients with acute stroke has been proven.