Predictors of poor outcomes in patients with pandemic viral infections (influenza AH1N1pdm09, COVID-19) on a ventilator.

ABSTRACT

Considering the commonality of the pathogenetic links of the critical forms of COVID-19 and influenza AH1N1pdm09 (cytokine over-release syndrome), the question arises will the predictors of an unfavorable outcome in patients on mechanical ventilation and, accordingly, the universal tactics of respiratory support in these diseases be identical? Objective. In a comparative aspect, to characterize patients with influenza AH1N1pdm09 and COVID-19 who were on mechanical ventilation, to identify additional clinical and laboratory risk factors for death, to determine the degree of influence of respiratory support (RP) tactics on an unfavorable outcome in the studied category of patients. Patients and methods. Patients treated on the basis of resuscitation and intensive care departments of the State Budgetary Healthcare Institution "SKIB" in Krasnodar and the State Budgetary Healthcare Institution "IB No 2" in Sochi were studied group 1 - 31 people with influenza AH1N1pdm09 (21 people died - subgroup 1A;10 people survived - subgroup 1B) and group 2 - 50 people with COVID-19 (29 patients died - subgroup 2A;21 people survived - subgroup 2B). All patients developed hypoxemic ARF. All patients received step-by-step tactics of respiratory support, starting with oxygen therapy and ending with the use of "traditional" mechanical ventilation. Continuous variables were compared in subgroups of deceased and surviving patients for both nosologies at the stages hospital admission;registration of hypoxemia and the use of various methods of respiratory therapy;development of multiple organ dysfunctions. With regard to the criteria for which a statistically significant difference was found (p < 0.05), we calculated a simple correlation, the relative risk of an event (RR [CI 25-75%]), the cut-off point, which corresponded to the best combination of sensitivity and specificity. Results. Risk factors for death of patients with influenza AH1N1pdm09 on mechanical ventilation admission to the hospital later than the 8th day of illness;the fact of transfer from another hospital;leukocytosis >=10.0 x 109/l, granulocytosis >=5.5 x 109/l and LDH level >=700.0 U/l at admission;transfer of patients to mechanical ventilation on the 9th day of illness and later;SOFA score >=8;the need for pressor amines and replacement of kidney function. Predictors of poor outcome in ventilated COVID-19 patients platelet count <=210 x 109/L on admission;the duration of oxygen therapy for more than 4.5 days;the use of HPNO and NIV as the 2nd step of RP for more than 2 days;transfer of patients to mechanical ventilation on the 14th day of illness and later;oxygenation index <=80;the need for pressors;SOFA score >=8. Conclusion. When comparing the identified predictors of death for patients with influenza and COVID-19 who needed mechanical ventilation, there are both some commonality and differences due to the peculiarities of the course of the disease. A step-by-step approach to the application of respiratory support methods is effective both in the case of patients with influenza AH1N1pdm09 and patients with COVID-19, provided that the respiratory support method used is consistent with the current state of the patient and his respiratory system, timely identification of markers of ineffectiveness of the respiratory support stage being carried out and determining the optimal moment escalation of respiratory therapy.Copyright © 2022, Dynasty Publishing House. All rights reserved.