Objective: to study oxygen transport impairments in ischemic stroke-induced coma in miners who have been doing underground work for more than 10 years. Subjects and methods. A prospective clinical study was conducted in 48 patients with coma caused by ischemic stroke. Group 1 included 12 miners. Group 2 comprised 36 men not working in coal miners. The groups did not differ in age, disease severity, and admission time. However, the group of miners had a higher incidence of pulmonary complications and therefore higher mortality rates. Comprehensive examination was performed and oxygen delivery index (DO2I), oxygen consumption index (VO2I), oxygen extraction ratio, and arteriovenous oxygen difference were calculated in all those admitted to hospital. Results. In ischemic stroke-induced comas, vasoconstriction resulted in the development of circulatory hypoxia with low DO2I. Then on day 3 respiratory and tissue hypoxia developed in the group of those who had a length of underground service. The relationship between DO2I and VO2I found in the miners suggests that impaired lung oxygenizing function was concurrent with oxygen transport system tension. The fact that there was no significant relationship of the oxygen saturation of hemoglobin in venous blood to VO2I in the miners had a high probability of indicating the development of tissue hypoxia. Such relationships were absent in the patients without underground length of service. Conclusion. The miners with an underground service length of 10 years or more and ischemic stroke-induced comas were found to have rapidly developing, more marked and long-term impairments of central hemodynamics, pulmonary oxygenizing function and hence the oxygen transport system as compared to those with no length of underground service. All the above characteristics are due to the lowered reserve capacities of the cardiovascular irnd respiratory systems upon long-term exposure to poor working conditions. Key words: ischemic stroke, oxygen transport, length of underground service, miner.

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.

Objective: to study the oxygen transport system in the acute period of ischemic stroke (IS). Subjects and methods. Central hemodynamics and the oxygen transport system were studied, intracranial pressure was measured, cerebral perfusion pressure was calculated and neurophysiological and X-ray studies were conducted in 36 patients in the first 7 days of IS. Results. In the first 5 study days, circulatory hypoxia developed due to evolving hypodynamic circulation. Later on, the situation was deteriorated by arterial hypoxemia due to acute respiratory distress syndrome and increased pulmonary shunting. Simultaneously on days 5 and 7, there were reductions in the oxygen consumption index and oxygen extraction coefficient, which was due to vasoconstriction, higher blood flow velocity, and lower oxygen extraction. Neurophysiological evidence was used to diagnose sub- and decompensation of stem structural functions. Conclusion. Vasoconstriction leads to the development of circulatory hypoxia. Thus, the early period of ischemic stroke is marked by the decreased oxygen delivery index due to the development of hypodynamic circulation. This is further attended by pulmonary complications and microcircula-tory disorders. On day 5 of the acute period, noncardiogenic pulmonary edema developed and pulmonary shunt increased, by worsening hypoxia. Impaired function of stem structures due to their damage, as evidenced by clinical, neurophysiologi-cal, radiological, and autoptic studies, is one of the causes of hemodynamic disorders, thereby impairing the oxygen transport system. Key words: acute cerebral circulatory disorder, oxygen transport system.

Objective: to study the time course of changes in extravascular lung water index (ELWI) and intracranial and cerebral perfusion pressures (ICP and CPP) and to determine their possible relationships in acute cerebral circulatory disorders (ACCD). Subject and methods. ELWI, pulmonary vascular permeability index (PVPI), ICP, CPP, and central hemodynamics were studied by transpulmonary thermodilution and current X-ray studies were conducted in 18 patients on days 1, 3, 5, and 7 of ACCD. Results. Examinations revealed a supratentorial dislocation of the brain in 6 persons; its subtento-rial dislocation was found in 1 case; supra- and subtentorial dislocations were seen in 6. In patients, ELWI and PVPI increased from days 1 and 5, respectively. The high baseline ICP increased over time. CPP remained unchanged. Preserved left ventricular contractility, enhanced myocardial one, a significant direct correlation between ELWI and PVPI, as well as their increase confirmed that the noncardiogenic genesis was responsible for increased ELWI. A direct significant correlation was found between ICP and ELWI, ICP and PVPI. Against this background, acute respiratory distress syndrome developed in 14 patients with pneumonia evolving in its presence in 7 patients. Conclusion. In ACCD, ELWI increases in the first 24 hours of the acute period. One of its causes is, along with others, primary and/or secondary damage to the brainstem structures with elevated ICP and progressive brain dislocation. The determination of ICP, unlike CPP, is crucial in the diagnosis and treatment of primary/secondary brain injuries and in prognosis. Key words: acute cerebral circulatory disorder, extravascular lung fluid, pulmonary vascular permeability, intracranial pressure, cerebral perfusion pressure, acute respiratory distress syndrome.

Objective: to study the time course of changes in extravascular lung water index (ELWI) and intracranial and cerebral perfusion pressures (ICP and CPP) and to determine their possible relationships in acute cerebral circulatory disorders (ACCD). Subject and methods. ELWI, pulmonary vascular permeability index (PVPI), ICP, CPP, and central hemodynamics were studied by transpulmonary thermodilution and current X-ray studies were conducted in 18 patients on days 1, 3, 5, and 7 of ACCD. Results. Examinations revealed a supratentorial dislocation of the brain in 6 persons; its subtento-rial dislocation was found in 1 case; supra- and subtentorial dislocations were seen in 6. In patients, ELWI and PVPI increased from days 1 and 5, respectively. The high baseline ICP increased over time. CPP remained unchanged. Preserved left ventricular contractility, enhanced myocardial one, a significant direct correlation between ELWI and PVPI, as well as their increase confirmed that the noncardiogenic genesis was responsible for increased ELWI. A direct significant correlation was found between ICP and ELWI, ICP and PVPI. Against this background, acute respiratory distress syndrome developed in 14 patients with pneumonia evolving in its presence in 7 patients. Conclusion. In ACCD, ELWI increases in the first 24 hours of the acute period. One of its causes is, along with others, primary and/or secondary damage to the brainstem structures with elevated ICP and progressive brain dislocation. The determination of ICP, unlike CPP, is crucial in the diagnosis and treatment of primary/secondary brain injuries and in prognosis. Key words: acute cerebral circulatory disorder, extravascular lung fluid, pulmonary vascular permeability, intracranial pressure, cerebral perfusion pressure, acute respiratory distress syndrome.

Objective: to study the central hemodynamics (CH) and intracranial and cerebral perfusion pressures (ICP and CPP) in acute cerebral circulatory disorders (ACCD) and their possible relationships for further development of intensive differential therapy for the detected disorders. Material and methods. Hemodynamic studies using the transpulmonary thermodilu-tion technique, measurements of ICP, calculations of CPP, and currently available X-ray studies were conducted in 18 patients on days 1, 3, 5, and 7 of ACCD. All the patients were found to have essential hypertension and coronary heart disease. Results. In the first 5 days of ACCD, there was a normodynamic type of circulation in hemorrhagic stroke (HS) and a hypodynamic type in ischemic stroke (IS). ICP remained at the baseline elevated level in the IS group and increased over time in the HS group. CPP was significantly unchanged. Myocardial dysfunction was detected when there was a significant preload caused by a high postload. In IS, an inverse correlation was found between ICP and global ejection fraction (GEF), cardiac performance index (CPI) and on day 7, the correlation was direct. In HS, ICP had a direct correlation with CPI and an inverse correlation with GEF. These changes during treatment failed to progress and were revealed in the presence of brain dislocation, as evidenced by spiral computed tomography. Conclusion. Thus, the pattern of CH disorders depends on the type of ACCD. In the first 5 days of ACCD, a hypokinetic circulatory type is registered in IS and a normokinetic type is in HS. Evolving dislocation of the brain with impaired function of its stem structures due to ICP elevation is one of the causes of central hemodynamic changes. The value of ICP in ACCD is a crucial indicator in the diagnosis of secondary brain damages and determines treatment policy. Key words: acute ischemic attack, intracranial pressure, cerebral perfusion pressure, central hemodynamics, myocardial depression.