A factor analysis of dyspnea indexes and lung function parameters in patients with chronic obstructive pulmonary disease.

The purpose of the present study was to investigate the correlation between dyspnea ratings and a large group of lung function parameters, and extract those factors that best reflect the functional profile of patients with COPD using factor analysis. Ninety nine patients with COPD in stable clinical condition (age 60 +/- 8 years, ATS score = 2.5 +/- 0.9, FEV1% pred. = 33 +/- 13%) were included in the study. The factor analysis of the results yielded 5 factors which accounted for 80.1% of the total variance of the changes. The highest coefficients found between the factors and the original group of variables after Varimax rotation are given in the following table: Factor 1: Oxygen-cost diagram: 0.92; ATS dyspnea score: -0.80; TL,CO/VA: 0.78; Factor 2: FEV1% pred.: 0.87; FEV1/VC%: 0.86; FEV1L: 0.79; Factor 3: MIF50% pred.: 0.85; FIV1% pred.: 0.76; PImax: 0.67; Factor 4: PaCO2: -0.81; SaO2: 0.77; Mean pulmonary arterial pressure: -0.67 Factor 5: Age: 0.88; Six minutes walk distance: -0.72 The factor analysis showed that the functional profile of COPD patients has several dimensions. Therefore, in order to have COPD comprehensively evaluated, assessment of dyspnea and the respective set of lung function parameters (exercise capacity, forced inspiration and pulmonary hemodynamics), should be included in the battery of tests, besides the conventional tests.

A patient with a severe chronic airway obstruction and preserved exercise capacity (a case report).

We report a patient with chronic obstructive pulmonary disease (COPD) in whom severe lung function disorders are combined with completely preserved exercise capacity. We assessed the exercise capacity of a 44-year-old man (height 155 cm, BMI 19.6 kg.m-2, FEV1%pred. = 30.9%, FRC%pred. = 158%, KCO%pred. = 46.2%, PaO2 = 64.0 mmHg, Medical Research Council Dyspnea scale = 1, Baseline Dyspnea Index = 10) by the 6-minute walking distance test (6MWD) and the symptom-limited cardiopulmonary exercise test (CPET) on a treadmill using the Bruce protocol. The patient was able to walk 667 meters in the test and achieved peak relative oxygen consumption (VO2/kg) of 21.9 mL.min-1.kg-1. We attribute the preserved exercise capacity of the patient to the combined beneficial effect of the following factors: 1. Efficient extraction of the hemoglobin-transported oxygen from the alveoli (P50 = 3.10 kPa). 2. Optimal right ventricle remodelling with mild hypertrophy, without dilatation and congestion. 3. Hypoxic normoxemia without polyglobulia, resulting in good rheologic properties of blood. 4. A preserved locomotory activity of the patient. Such a combination of severe lung function disorders with mildly pronounced dyspnea and preserved exercise capacity supports the concept that the function profile of COPD patients is multidimensional and therefore such patients should have a complete assessment of their disability condition.

[Diagnostic algorithm and software for assessment and follow-up of dyspnea]. / [Diagnostichen algorit'm i programa za otsenka i proslediavane na dispneiata]

Breathlessness is a common complaint among patients with lung and heart diseases. It is a complex, multidimensional symptom with descriptive and quantitative aspects. The aim of this study is to constitute a set of questionnaires and scales for adequate assessment of dyspnea and their combination in diagnostic algorithm with various ranges. In order to achieve this goal, we developed a software product DISKO with the following characteristics: Includes the basic instruments for assessing dyspnea in all dimensions--verbal (descriptive) characteristic, everyday activities and exercise dyspnea, as well as its impact on the patients' quality of life. Proposes minimal, optimal and comprehensive algorithm for assessment and follow up of dyspnea. Presents a convenient interface and an ability to configure a flexible data base easy for browsing and handling. Proposed tests and algorithm for dyspnea assessment make it easier for the physician to diagnose and follow up chronically ill patients whose major complaint is dyspnea. The software product DISKO is compliant with the modern requirements for medical software and can be utilized in the process of diagnostic, education and scientific research.

Functional parameters in pulmonary bullous emphysema.

OBJECTIVE: 1. compare a large set of functional parameters in patients with bullous emphysema and patients with nonbullous emphysema. 2. To compare a chest radiographs (CHR) and a high resolution computed tomography (HRCT) in the clinical assessment of bullous emphysema. MATERIAL AND METHODS: The study population included 43 stable COPD patients (age = 59 +/- 9 years; pack/year (P/Y) = 39 +/- 19; ATS dyspnea score = 2.3 +/- 0.9; FEV1%pred. = 30 +/- = 10%; KCO%pred. = 49 +/- 16%; 6MWD (six minute walk distance) = 395 +/- 103 m; mean +/- SD). The patients were divided into two groups (patients with and without bullae) by a HRCT. In most of the cases the size of the bullae, measured by CT scan, was less than 15 mm. Twenty two CHRs were read independently by three experienced chest radiologists who had no knowledge of the CT scan data. RESULTS: Statistically significant differences were found between the groups with bullous (n = 19) and nonbullous (n = 24) emphysema in FEV1 (p < 0.001); VC (p = 0.001); BMI (p = 0.018); Borg after exercise (p = 0.021); FEV1/VC% (p = 0.025) and P/Y (p = 0.034). The sensitivity of chest radiographs compared with CT scan regarding the small bullae was very low: 27.7% in radiologist I, 12.3% in radiologist II, and 21.5% in radiologist III. CONCLUSIONS: 1. The patients with bullous emphysema have statistically significant lower lung function indices (FEV1, VC, FEV1/VC%) and BMI than those with nonbullous emphysema. 2. Patients with bullous emphysema have higher level of dyspnea score after 6MWD and higher pack-year smoking status than those with nonbullous emphysema. 3. For the clinical evaluation of emphysema the information derived from a standardised reading of the CXR is not as valuable as that derived from the CT scan.

Algorithm for assessment of the oxygen, acid-base and electrolyte status (ALBOA BEACH).

To achieve accurate interpretation of blood gas analysis data in intensive care units, the oxygen, acid-base and electrolyte-metabolite profile of arterial blood should be comprehensively and adequately monitored and assessed. A number of diagnostic software programmes have been developed to assist clinicians in this and to help improve instruction in this field. In the present study we describe an algorithm and a programme for assessment of the oxygen, acid-base and electrolyte status of the arterial blood. The algorithm, as well as the software programme, is named ALBOA BEACH, which is an acronym of the programme's full name--ALgorithm for Blood Oxygen, Acid-Base, Electrolyte And respective CHarts. The algorithm takes account of the latest achievements in blood-gas analysis; it can be used both in on-line and off-line modes and is useful in the laboratory and pathophysiological assessment of blood-gas disorders. The algorithm is based on a rigorous pathophysiological analysis and the interpretation achieved as a result is much more accurate than usual. Thus it provides a most reliable basis for taking the right clinical decision and making the proper prognosis of the possible critical conditions. The algorithm also provides additional bases for interpretations of data in the borderline zones, with due warnings in cases of absence of physiological coherence between the various parameters and modules. The programme is designed to be used with the modern multifunctional blood-gas analysers; it can be of assistance in making diagnoses, in the training and research activity in the intensive care units and specialised blood gas laboratories.

Characteristics of tidal expiratory flow pattern in healthy people and patient with chronic obstructive pulmonary disease.

According to data reported in literature tidal breathing parameters and especially tidal expiratory flow pattern parameters can be useful in distinguishing airflow obstruction. The purpose of the present study was to investigate the parameters of the tidal breathing in healthy people and patients with chronic obstructive pulmonary disease. The study sample included 158 patients with COPD in clinically stable condition and different degree of functional disturbances (FEV1% pred. = 42% +/- 15%; ATS dyspnea scale = 2.5 +/- 0.9; mean +/- SD). The control group of healthy subjects consisted of 43 men and 37 women. The obtained results show that TPTEF/TE (the time necessary to reach the peak expiratory flow in tidal breathing over the total expiratory time) and VPTEF/VE (the volume necessary to reach the peak expiratory flow in tidal breathing over the total expiratory volume) are an independent aspect of tidal breathing. In healthy people these parameters show weak negative correlation with age and high variability. In COPD they are statistically significantly lower than those of healthy people but, since they are highly variable, they cannot be used for an individual assessment. The increase of the mean inspiratory flow (TV/Tin) and the shortening of VPTEF/VE, TPTEF/TE and Tin/Ttot, are indicative of the lung mechanics changes which have a bearing on dyspnea, too. According to factor analysis the parameters of tidal breathing are four separate dimensions: 1. Breathing frequency and respiratory times; 2. Relationship between the respiratory times; 3. Minute ventilation, mean expiratory flow, mean inspiratory flow and tidal volume; 4. Parameters of the expiratory flow VPTEF/VE and TPTEF/TE. The parameters of forced expiration and those of tidal breathing are separate dimensions of the functional profile of patients with COPD.

Local effects on the blood gas indices in diaphyseal forearm fractures.

We studied the local changes of blood gas indices of arterialised capillary blood taken simultaneously from the fractured and the uninjured arm of 30 patients with diaphyseal fractures of the forearm. Blood gases were measured with a Stat Profile 5 analyser (Nova Biomedical). The results indicate a slight but statistically significant decrease of the acid-base indices without any changes in the oxygen indices. These slight changes do not affect considerably the diagnosis of the profile.

A new index for assessing arterial oxygen profile in patients with respiratory failure.

A new index, termed 'useful ratio' of the blood oxygen binding curve, was derived on the basis of the characteristic features of hemoglobin oxygen (transported, reserve and practically non-usable hemoglobin oxygen). The index gives the ratio of the useful to the predicted total hemoglobin oxygen of patients. It is functionally related to the fraction of the measured transpulmonary shunt (FShunt), shows high correlation with the blood gases (pO2 and pCO2), correlates moderately with the hydrogen exponent, poorly with the oxygen affinity (P50) and the metabolic acid-base parameters (cHCO3), and does not show to be essentially related to the total oxygen concentration (cO2) and PO2(x), the new index proposed in the Oxygen Status Algorithm. Diagnostically, this index has much the same value as that of the calculated shunt (FShunt); it can be used only in diagnosing the conditions of hyperoxia, normoxia, and hypoxia and excludes detecting those of hyperoxemia, normoxemia, and hypoxemia. Simultaneous assessment of this index together with pO2(x) enhances further the diagnostics of respiratory insufficiency providing the necessary information about the mechanism of respiratory decompensation that is of importance for an efficacious treatment.

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.

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%.

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.

Studies on the plasma cholesterol and triacylglycerols in chronic methemoglobinemia in rats.

Plasma cholesterol and triacylglycerols were measured in rats with modelled chronic two-stage (mild and moderate) intermittent nitrite methemoglobinemia for 15 and 30 days. It was found that at the moment of methemoglobinemic peak (60 +/- 10 min) the experimental animals had mixed (hemtoxic, anemic and hypoxic) hypoxemia. The every day "pulse" decrease of the total oxygen concentration during the 30-day methemoglobinemia was accompanied with a significant rise (p < 0.05) of cholesterol concentrations in the high-density lipoproteins and the total cholesterol, as well as a decrease in the amount of triacylglycerols. These changes are considered to represent the side effects of adaptation for whose elucidation further research is needed.

[Nomograms developed for determining the acid-base and oxygen status of cattle]. / Razrabotvane nomogrami za opredeliane na alkalno-kiselinniia i kislorodniia status pri govedoto.

Investigations were carried out on a total of 66 lactating cows in order to work out an Octane nomogram for the direct recording of the PO2/HbO2 interrelationship and determine the normal alkali-acidic range in cattle. It is stated that these studies have made it possible to speculate on the clinical veterinary normal values of each particular index of the alkali-acidic balance and its prompt calculation.