Impairments in Gas Exchange and Mechanical Properties of the Lung in Miners in Comas Induced by Acute Ischemic Stroke

Abstract

Objective: to study the specific features of lung gas exchange and mechanical properties in comas induced by acute stroke (AS) in miners having an underground length of 10 years or more for the further optimization of intensive care. Subject and methods. Gas exchange (oxygenation index (PaO2/FiO2), the degree of intrapulmonary blood shunting (Qs/Qt)), the mechanical properties of the lung (mean airway pressure (Pmean), airway resistance (Raw), static thoracopulmonary compliance (Cltst)), and intracranial pressure (ICP) were studied and brain spiral computed tomography was conducted on days 1, 3, 5, and 7 of the acute phase of AS in 49 patients. The patients were divided into 2 groups: 1) 12 miners (pensioners) (a study group) and 2) 37 patients without underground work length (a control group). Results. Pmean values increased in both groups on days 3 to 7, rose on day 5 in miners. Cltst was decreased and Raw increased. PaO2/FiO2 decreased on days 3—5, more in the miners and Qs/Qt increased ICP persisted in the upper normal range in both groups. The miners were found to have a higher incidence of pneumonias than the patients having no underground length and the former had longer mechanical ventilation and a higher overall mortality. Conclusion. As compared to the patients without underground length, the miners with existing baseline changes in the respiratory organs showed earlier and pronounced development of impairments in gas exchange and the mechanical properties of the lung in the presence of comas induced by acute stroke. This leads to severer acute respiratory distress syndrome, increases the frequency of other complications, irnd results in higher mortality in this group of patients. Keywords: ischemic stroke; coma; gas exchange; mechanical properties of the lung; underground work length; miner.