PubMed Health⌕ Search

Biomedical subjects

S Kostianev

Publications and source records attributed to S Kostianev.

33 records · Page 2Linked to original sources
PubMed1996

Partial relaxation of diaphragm and lung function parameters.

The present study investigates the effect of partial relaxation of diaphragm on the lung functions in the absence of active lung and neuromuscular disorders. Comprehensive functional tests of the breathing was performed on 22 subjects with partial relaxation of the diaphragm (elevated hemidiaphragm) found during an X-ray study on the occasion of gastrointestinal disorder. On the basis of the results of two group of patients, one with ventilatory disorders (n = 9-4 men and 5 women) and another with normal lung ventilation (n = 13-7 men and 6 women) the conclusion was drawn that in the absence of additional pathology the partial relaxation of the diaphragm does not causes any changes in the lung function parameters with the exception of the tendency towards low values of the parameters for the respiratory muscle strength (PImax and PEmax).

Blood Gas Analysis↗
PubMed1996

A model for standardization of lung function parameters by height.

Lung function parameters are closely associated with the height of the individual and this is the reason why this genetically determined characteristic is present obligatorily in the equations giving their reference values. The present work studies a large group of models by analysing two groups of healthy individuals - 20 healthy boys aged 7 to 14 years (10.6 +/- 2.2; mean +/- SD) with a height of 121 to 170 cm (145.0 +/- 14.2) and 98 healthy men aged 30 to 60 years (44.7 +/- 6.7) with a height of 159 to 192 cm (171.0 +/- 9.1), all of them non-smokers. Statistical analysis shows that standardization of lung function parameters by height of healthy individuals is achieved by using a power function of the height - FEV1/2.7 and VC/H2.6 for boys aged 7 to 14 years and FEV1/H2.5 and VC/H2.4 for men aged 30 to 60 years. The model proposed for children practically neutralizes age completely and can be used as a reference equation. The graphic and correlation analysis of the residuals obtained as a difference between the actual and predicted values of the respective models indicated clearly presence of age peculiarities. In men the correlation coefficients between the residuals and the height were close to zero, and the residuals themselves were relatively evenly distributed around the zero line (a homoscedastic distribution). In children the differences scattering increased with the height, i.e. there is a heteroscedastic distribution.

Adolescent↗
PubMed1995

Blood gases, electrolytes and metabolic monitoring in children with acute failure of vital functions.

The priority of direct monitoring of blood gases in Paediatric Intensive Care Units (PICU) increased substantially after introduction of the Deep Picture method and Oxygen Status Algorithm (OSA) (1) into medical practice. We used the advantages of these methods as a prerequisite for a more detailed and deeper analysis of the blood oxygen profile (2, 3). The aims of the present paper were: 1. To illustrate the applicability of the capacity coefficients beta 1.0, beta 2.3, beta 5-4 of the transported oxygen and the "Useful Ratio" (UR) index of the haemoglobin oxygen, previously described by us, and the benefit derived from differentiation of the states of hyperoxia, normoxia and hypoxia; hyperoxaemia, normoxaemia and hypoxaemia on the Blood Oxygen Binding Curve (BOBC) in critically ill newborns, infants and children. 2. To expand the diagnostic capacity of the Blood Gas Map (BGM) used with the OSA in children and to supplement the arterial oxygen diagnostics with new indices that reflect the relationship between oxygen uptake and oxygen transported in the body. 3. To share our experience in PICU related to the acid-base-electrolytes relationship and to the possibility of assessing the reno-hepatic regulation according to the changes of the acid-base status in critically ill children.

Acid-Base Equilibrium↗
PubMed1994

A new approach to the evaluation of bronchodilatator response.

Despite the widespread use of the bronchodilatator test in lung function testing, there is still disagreement on the clinical value of the methods of measurement and the quantitative criteria for assessment of the bronchodilatator response. A comparative analysis is made in the present study of five wide-known techniques of measuring bronchodilatator response (BDR) based on the change of FEV1.0 (delta FEV1.0) after administration of salbutamol in 20 patients with chronic bronchial asthma. An approach is proposed which uses the mean of predicted and initial values of FEV1.0 in the denominator. The results show that relating delta FEV1.0 to the mean of initial and predicted values of FEV1.0 (in the proposed method) or only to the initial value of FEV1.0 (in the method recommended lately by the European Respiratory Society) offers specific advantages for the analysis of bronchodilatator response which makes these methods worth trying in diagnostic practice.

Adult↗
PubMed1994

Clinical evaluation of the ETOS pneumotachograph.

The present study aimed at testing clinically the computerized pneumotachograph ETOS, a joint Bulgarian-Russian manufacture. It was evaluated by comparing its performance with that of a similar pneumotachographic system made by JAEGER, Germany. 20 patients with chronic obstructive pulmonary disease and 21 healthy subjects were enrolled in the study. Each of the pneumotachographs was used first to generate separately enveloped maximal expiratory flow-volume curves. Then, with the machines in series, they were used for the analyses of single forced expirations. The results for linearity, systematic and random errors showed the ETOS pneumotachograph to be reliable for the values of the major forced expiration parameters--FVC, FEV1.0, PEF and MEF50%.

Adult↗
PubMed1994

New parameters for evaluation of oxygen transport on the dissociation curve of human blood.

Three new parameters were applied to evaluate oxygen transport using the dissociation curve of human blood. They are derived from the following equation: [formula: see text] The first parameter, beta 1,0, reflects the oxygen capacity of the curve within the range of 1.0 kPa at its "arterial section". The second parameter, beta 2,3, reflects the oxygen transport from the "arterial" point to the point of extraction of 2.3 mmol/l-1 of oxygen which is assumed as normal. The third parameter, beta 5-4 kPa, characterises the oxygen transport at the "venous" section of the curve. The parameters were studied on a cohort of 12 healthy people and 141 patients with chronic obstructive pulmonary disease at different stages of respiratory failure. A significant correlation was found between the oxygen capacity parameters, beta 1,0 and beta 2,3, and pO2(a), sO2 and the calculated transpulmonary shunt. They were not influenced by ctHb and ctO2(a). beta 5-4 showed marked correlation with the hemoglobin and total O2 concentration and the parameters that indicate a risk of tissue hypoxia-px and Qx. Standardisation of the new parameters with ctO2(a) correlates it functionally with the parameters of oxygen affinity.

Adult↗
PubMed1994

Tobacco smoking (up to 10 cigarettes daily) and lung functions in pregnant women.

The main objective of this paper was to study the effect of tobacco smoking (up to 10 cigarettes daily) on lung functions of healthy pregnant women as part of a large scale foetus antenatal care programme. Seventy eight pregnant women with no history and clinical evidence of pulmonary, cardiac, obstetrical or gynecological diseases were subjected to a comprehensive functional investigation of breathing. The women, all in the tenth lunar month of pregnancy, were divided into four categories: non-smokers, ex-smokers that have quitted smoking after diagnosing of pregnancy, with a mean of 2.0 +/- 1.2 pack-years of smoking (mean +/- SD), and current smokers with 3.1 +/- 1.9 pack-years of smoking. The results obtained show that light smoking causes no essential changes in the lung function parameters of pregnant women with the exception of the reduction tendency of the parameters of airway conductance and the strength of the respiratory muscle (PImax and PEmax).

Adult↗
PubMed1994

External respiration in patients with chronic renal failure in a predialysis state.

The purpose of this study was to make functional assessment of the external respiration in patients with chronic renal failure (CRF) in a predialysis state and to find some early indicators for uremic lung impairment. Twenty two patients (13 men, 9 women, aged 30 to 65) with different renal diseases were investigated. According to the stage of progression of CRF we allocated the patients to two groups-14 patients with stage I CRF (serum creatinine up to 353.6 mumol/I), and 8 patients with stage II CRF (serum creatinine from 353.6 to 707.2 mumol/I). The comprehensive functional study included slow spirometry, forced expiration, bodyplethysmography, and investigation of the diffusion, blood-gas and acid-base parameters. The respiratory muscle strength was measured by means of a modified device first used by Black LE and Hyatt RE. Ventilatory parameters in stage I CRF patients were found to be either normal or slightly changed while the parameters of the respiratory muscle strength worsened earlier than the ventilatory parameters. In the patients with stage II CRF the pronounced ventilatory and diffusion disorders was found to occur much more frequently.

Adult↗
PubMed1993

Screening of the respiratory functions of workers engaged in bearing manufacture.

The lung functions of 285 workers were investigated. It was found that the ventilatory functions of 20.5% of the female and 23.5% of the male testes were impaired. Prevalence of mild obstructions was established which can be attributed to both cigarette smoking and the length of service. Maximal expiratory flows are worth a special attention in mild airflow obstructions as they could be decreased when forced expiratory volume in the first second (FEV1) remains unchanged.

Adult↗
PubMed1993

Body-plethysmographic pressure-flow diagrams in chronic obstructive lung disease. II. Functional assessment.

One hundred patients with various forms of chronic obstructive lung disease (COLD) were allocated to groups according to their body-plethysmographic pressure-flow diagrams. Group I comprised 30 patients with resistance curves displaying linear relationship between pressure and flow. The second group (n = 30) was formed by patients who had a markedly pronounced hysteresis in the central parts of their resistance curves. Group III consisted of 30 patients who exhibited resistance curves with distended expiratory sections. Group IV's patients (n = 10) had eight-shaped resistance curves. The lung function profiles of these patients were obtained by measuring the parameters of forced expiration and static lung volumes, the diffusion, blood-gas and acid-base parameters. The analysis of the results shows progressive aggravation of airway obstructions from Group I to Groups III and IV the latter two groups having similar lung function characteristics. Another corollary is that the resistance curve configuration reflects to a great extent the severity of the lung mechanics disorders, but does not correspond entirely to the clinically established forms of the chronic obstructive lung disease.

Adult↗
PubMed1993

Body-plethysmographic pressure-flow diagrams in chronic obstructive lung disease. I. Comparative measurements.

One hundred patients with various forms of chronic obstructive lung disease were allocated to groups according to their body-plethysmographic pressure-flow diagrams. Group I comprised 30 patients with resistance curves displaying linear relationship between pressure and flow. The second group (n = 30) was formed by patients who had a markedly pronounced hysteresis in the central parts of their resistance curves. Group III consisted of 30 patients who exhibited resistance curves with distended expiratory parts. Group IV's patients (n = 30) had eight-shaped resistance curves. The comparative measurements on these 4 types of body-plethysmographic pressure-flow diagrams included all kinds of airway resistances, as well as their components and ratios (Raw, Rpeak, R, Raw(in), Raw(ex), R(ex), R(in), Raw/R, Raw(ex)/R(ex), Raw(in)/R(in), Raw(ex)/Raw(in), R(ex)/R(in)). The analysis of the results shows that the quantitative criteria used in the assessment undergo the greatest change in the eight-shaped loops and in those resistance curves whose expiratory parts are considerably distended. The difference between the absolute values obtained by using the basic methods of calculating airway resistance is the greater the weaker is the linear relationship between pressure and flow.

Adult↗
PubMed1993

Relationships between blood oxygen parameters in patients with chronic obstructive lung disease.

The hemoglobin-oxygen dissociation curve and the relationships between the parameters of tension, saturation, capacity, affinity and concentration of oxygen in the course of respiratory failure in chronic obstructive lung diseases (COLD) were studied. The study included 141 patients divided into four basic groups according to the value of pO2 (a): patients with normoxia, mild, moderate and severe arterial hypoxia. The blood-gas status was determined using the ABL-330 and OSM-3 analyzers (Radiometer A/S, Denmark). It is concluded that: 1. Presence of normoxia (pO2 and sO2 in norm) in COLD patients does not exclude abnormalities in their arterial blood oxygen transport and increased risk of tissue hypoxia. 2. Total oxygen concentration in respiratory failure is relatively stable and "independent" from the stepwise decrease of the arterial pO2, which results from the compensatory increase of the total and effective hemoglobin. 3. There are phase fluctuations of the ctO2/pO2 dissociation curve in the reference interval, expressed in the "lowering" of P50 and p90 in mild hypoxia and the "centering" or "raising" of their values in severe hypoxia. Such fluctuations are more pronounced in the p90 than in the p50. 4. The oxygen extraction tension lowers progressively (without reaching the anaerobic threshold) and the oxygen compensation factor elevates with the pO2 (a) reduction and the arising of hypercapnia and acidemia. 5. The calculated 2,3-diphosphoglycerate (2,3-DPG) concentration values are significantly higher in hypercapnics with COHb > 1% than in those with COHb < 1%. The relationships between hypoxia, oxygen affinity, hemoglobinemia and oxygen affinity as well as the dissociation curve properties in chronic respiratory failure are discussed.

Acid-Base Equilibrium↗