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Biomedical subjects

S Kostianev

Publications and source records attributed to S Kostianev.

At least 19 recordsLinked to original sources
PubMed2003

University of Cincinnati Dyspnea Questionnaire for Evaluation of Dyspnoea during physical and speech activities in patients with chronic obstructive pulmonary disease: a validation analysis.

University of Cincinnati Dyspnea Questionnaire (UCDQ) was developed to measure the impact of dyspnoea during (1) physical activity (Phys), (2) speech activity (Speech) and (3) simultaneous speech and physical activity (Comb). The aim of this study was to evaluate the validity of UCDQ in COPD patients, comparing it to a large set of dyspnoeic indices and functional parameters. Fifty COPD patients (age 58.7 +/- 9.1 years, FEV1%pred = 39.3 +/- 17.0%, Baseline Dyspnoea Index (BDI) = 4.9 +/- 2.5, Six Minute Walk Distance (6MWD) = 373 +/- 128 m, Symptoms score = 9.4 +/- 2.5; mean +/- SD) participated in the study. We found the following mean scores for the three sections of the questionnaire: Phys = 3.5 +/- 0.9; Speech = 2.4 +/- 1.1; Comb = 4.2 +/- 1.0, meaning that patients report the most breathlessness during the combination of speaking and physical activity and the least breathlessness during speech activities. All three section of UCDQ had significant strong correlation with dyspnoea indices (BDI, Borg, MRC, OCD), 6MWD and symptoms score, which proves its concurrent and construct validity. Differentiation of patients by speech section (=3<) discriminated them significantly with respect to all dyspnoeic indices, symptoms score and 6MWD. All three dimensions of UCDQ had high test-retest reliability - ICC between 0.76 and 0.93. Factor analysis yielded three interpretable factors, as all dyspnoeic indices, three sections of UCDQ, symptoms score and 6MWD were loaded on the first factor. In conclusion, UCDQ provides valid and reliable information about the effect of dyspnoea on speech and daily activities.

Aged↗
PubMed2003

Modified treadmill protocol for evaluation of physical fitness in pediatric age group--comparison with Bruce and Balke protocols.

The aim of this study was to compare classical Balke and Bruce protocols with our modification of Balke protocol in pediatric cardiorespiratory diagnostics. The modification of Balke consists of nine stages per 1 min at a constant velocity of 5.6 km x h(-1) and increasing elevation from 6% to 22% in 2% increments. Sixty healthy children (mean age = 13.3+/-0.2 years; BMI = 18.8+/-0.6 kg x m(-2); mean +/- 95% CI), divided into three groups of 20 children each, matched by age, height and BMI performed integrative cardiopulmonary exercise testing using one of the treadmill protocols mentioned. At the end of each exercise increment and throughout the recovery period the children were asked to rate the perceived exertion (RPE) using the Borg Category Ratio scale--CR-10. Exercise results showed that Balke protocol had the longest duration (21.7+/-0.6 min.) and the lowest values for VO2/kg (34.2+/-1.8 ml x min(-1) x kg(-1)) due to the minimal workload increments. Bruce protocol had intermediate duration (14.9+/-1.1 min.) and children achieved the highest VO2/kg (48.6+/-2.7 ml x min(-1) x kg(-1)) but the test is symptom-limited which is ethically unacceptable in childhood. Exercise data revealed that our modification of the classical Balke protocol had an optimal duration (11 min.) and yielded peak VO2/kg values (39.4+/-2.3 ml x min(-1) x kg(-1)) adequate for evaluation of children's exercise capacity. Children's ratings of perceived exertion were highest in Bruce protocol (6.5+/-0.4) and lowest in the original Balke protocol (4.5+/-0.8). In conclusion, the modification of Balke protocol is suitable and reliable for screening and clinical testing in pediatric age group.

Adolescent↗
PubMed2003

Exercise performance and oxygen uptake efficiency slope in obese children performing standardized exercise.

Oxygen uptake efficiency slope (OUES) is an index meant to provide an objective measure of cardiopulmonary function at submaximal exercise. The aim was to study the exercise performance and OUES in obese children performing standardized exercise. Sixty children aged 6-17 years performed incremental treadmill exercise test. They were divided into two groups matched by age, sex and height: thirty obese subjects (15 girls/15 boys; BMI = 27.4+/-1.7 m x kg(-2)) and 30 controls (BMI = 18.8+/-1.0 m x kg(-2)). Perceived exertion was assessed by means of CR-10 Borg scale. The duration of the exercise for the obese children was significantly shorter than for controls (p = 0.010) but obese children had greater absolute values for oxygen uptake (VO2 peak mL x min(-1) = 1907+/-249 vs. 1495+/-208; p = 0.013) which, adjusted for body mass, decreased significantly (VO2/kg mL x min(-1) x kg(-1) = 29.2+/-1.4 vs. 33.6+/-1.3; p < 0.001). OUES correlated strongly with VO2 peak (r = 0.91) and oxygen pulse (r = 0.80), as well as with anthropometric variables height (r = 0.88) and age (r = 0.83). Extremely high correlation was found between OUES calculated for 100% of exercise duration and OUES at the anaerobic threshold (r = 0.979; p < 0.001). No significant differences were found between the studied groups concerning the absolute values of OUES. Obese children rated perceived exertion significantly higher than controls (Borg score 6.2+/-0.4 vs. 5.2+/-0.4; p = 0.001). In conclusion, the absolute metabolic cost of exercise and perceived exertion were higher in the obesity group. OUES is an objective measure of cardiopulmonary reserve that doesn't require a maximal effort but it is considerably dependent on anthropometric variables which impedes its interpretation as exercise index in childhood.

Adolescent↗
PubMed2002

Ventilatory efficiency and rate of perceived exertion in obese and non-obese children performing standardized exercise.

Sixty children, in the age span 6-17 years originally divided into two groups, matched by age, sex and height--30 obese subjects [15 girls/15 boys; body mass index (BMI) = 27.4 +/- 4.5 m kg-2; ideal body weight (IBW) range = 122-185%] and 30 controls (BMI = 18.8 +/- 2.7 m kg-2) performed incremental treadmill exercise test. Perceived exertion was assessed by means of Category-Ratio Borg scale. The duration of the exercise for the children in the obesity group was significantly shorter than controls (P = 0.010) but obese children have greater absolute values for oxygen uptake (VO2peak ml min-1 = 1907 +/- 671 versus 1495 +/- 562; P = 0.013) and ventilatory variables (VE, VT), which adjusted for body mass decrease significantly (VO2/kg ml min-1 kg-1 = 29.2 +/- 3.8 versus 33.6 +/- 3.5; P < 0.001). Among the various methods for 'normalizing' absolute values of VO2peak for body size, dividing it by body surface area (BSA) yielded the best results (VO2/BSA ml min-1 m-2 = 43.5 +/- 4.6 versus 44.7 +/- 5.6; P = 0.335). The ventilatory efficiency determined either as a slope of VE versus VCO2 or as a simple ratio at anaerobic threshold did not differ between obese and non-obese children in the incremental and recovery periods of exercise. There was a negative correlation of VE/VCO2 slope with age and anthropometric parameters. Obese children rated perceived exertion significantly higher than controls despite the standard workload (Borg score = 6.2 +/- 1.2 versus 5.2 +/- 1.1; P = 0.001). In conclusion, the absolute metabolic cost of exercise is higher in the obesity group compared with the control subjects. Both groups have similar ventilatory efficiency but an increased awareness of fatigue that furthermore limits their physical capacity.

Adolescent↗
PubMed2000

[Diagnostic algorithm and software for assessment and follow-up of dyspnea].

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.

Algorithms↗
PubMed2000

Ventilatory response to exercise and rating of perceived exertion in two pediatric age groups.

The aim of this paper is to study the differences in ventilatory response to exercise in prepubertal and pubertal children. One hundred children in the following groups: 10-year-olds (25 boys/25 girls) and 13-year-olds (25 boys/25 girls) performed sub maximal treadmill stress test, using modified Balke protocol. All of them went through complex pulmonary function testing and complete anthropometrics measurements, including skinfold thickness. The relative oxygen consumption for the whole group is 38.5 +/- 4.5 mL/min/kg (mean +/- SD). The girls had higher percent fat than boys in both groups (24% vs. 16% in the first group and 27% vs. 18% in the second). With age VO2peak grows parallel with minute ventilation, tidal volume and a tendency towards lowering the breathing frequency is observed irrespective of the sex. We found significant sex differences in ventilatory equivalents for oxygen and carbon dioxide in the second group. VE/VCO2 for the boys decreased from 30.6 +/- 3.1 to 27.6 +/- 2.9; p = 0.002, but remains unchanged in girls. Another interesting fact is that older children rated perceived exertion significantly higher (Borg score 4.6 +/- 0.9 vs. 5.5 +/- 1.4; p < 0.05) despite the standard load. In conclusion there are age and sex differences in some aspects of ventilatory response in pediatric age group.

Adolescent↗
PubMed1999

Effects of short-term exercise training in patients with heart failure.

Heart failure is a debilitating disorder which limits exercise capacity and produces a poor quality of life. The present study was designed to determine the effects of an exercise training program on patients with CHF NYHA functional class II-III, attributed to left ventricular systolic dysfunction and dilated left ventricle. Twenty-two ambulatory male patients with stable CHF were randomised to a training (n = 15) and a control group (n = 7). A symptom limited ramp cardiopulmonary exercise test with gas exchange analysis was performed at baseline after 4 and 8 weeks. The training group underwent an exercise training program at 50% of peak oxygen uptake for eight weeks. The control group was not exercised. After 8 weeks, compared with baseline, there were statistically significant increase in peak oxygen uptake, peak workload, anaerobic threshold, oxygen pulse, RPP, ventilation and the duration of the test only in trained patients. The reduction in scores tested by the Minnesota Living with Heart Failure questionnaire (p < 0.001) and Borg dyspnea rating score (p < 0.001) reflect the reduction of symptoms and the improvement in health-related quality of life. Carefully selected patients with moderate to severe CHF can achieve significant improvements of exercise capacity and quality of life with exercise training and can safely participate in a conditioning program.

Exercise↗
PubMed1999

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.

Aged↗
PubMed1999

Effect of complex sanatorium treatment on some dyspnea indices in patients with chronic obstructive pulmonary disease.

The complex treatment of patients with chronic obstructive pulmonary disease (COPD) administered in a sanatorium environment is an effective therapeutic option for this condition as it involves conduction of a combination of climatic, therapeutic and rehabilitation procedures for a longer period of time. We studied the effect of this therapeutic modality on the dyspnea indices of COPD patients and the implication these indices have for the outcome of the treatment. The study was performed in the sanatorium of the State Hospital for Lung Diseases in Raduntzi, Bulgaria. It included 75 patients (65 men, 11 women) with different forms of stable COPD (mean age, 56.8 +/- 1.0 years, mean +/- SEM, FEV1% predicted--37.3 +/- 1.6%, mean duration of sanatorium stay 14 +/- 0.4 days). During the stay the patients received anti-obstructive and anti-inflammatory therapy based on the clinical discretion of the attending physician. All patients attended a rehabilitation programme according to their conditions; oxygen therapy was used in three patients. Of the 75 patients, 50 (66.7%) showed improvement at discharge, 21 (28%) had no improvement, and 4 (5.3%) were discharged in deteriorated condition. The complex treatment resulted in a minimal but statistically significant improvement of the basic spirographic and dyspnea parameters. This improvement depended not so much on the type of therapy administered as on the initial dyspnea and blood gas parameters. The body mass index (BMI) can also be used as a prognostic indicator especially if it is lower than 20 kg/m2. The lower this index is the lower the basic functional parameters are--in spite of using all available treatments, our patients with low body mass index rarely showed any noticeable improvement.

Anti-Inflammatory Agents↗
PubMed1999

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.

Adolescent↗
PubMed1999

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.

Acid-Base Equilibrium↗
PubMed1999

Comprehensive assessment of ventilatory functions of patients with chronic heart failure.

OBJECTIVE: A comprehensive assessment of the ventilatory functions of patients with chronic heart failure (CHF) both at rest and during a cardiopulmonary exercise test (CPET). We studied 42 males, divided into two groups--patients with CHF (n = 21) and age, weight, height and BMI matched healthy controls (n = 21). All subjects underwent a symptom-limited ramp CPET, arterial blood gas analysis, and complex functional examination of the pulmonary system. Subjective rating of dyspnea and exertion were measured by the Borg and ATS dyspnea scales. CHF patients showed a slight, but statistically significant decrease of the spirographic and diffusion parameters, as well as of the indices of respiratory muscle strength. There were no changes in blood gases and in tidal breathing parameters. The exercise capacity was markedly reduced (VO2peak ml.min-1 1352 +/- 335 CHF patients vs 2077 +/- 276 healthy controls; p < 0.001) and the anaerobic threshold occurred earlier (< 40% of predicted VO2peak) during CPET in CHF patients. The increase in VE/VCO2 in CHF patients (35.7 +/- 5.1 CHF; 28.9 +/- 2.5 HC, p < 0.001) indicates a compromised ventilatory efficiency which leads to a higher dyspneic cost of exercise (Borg peak 9.5 +/- 1.03 CHF; 6.0 +/- 1.28 HC; p < 0.001) as compared with healthy controls.

Adult↗
PubMed1999

Individual results of treatment of COPD with low doses of fenoterol compared with treatment with ipratropium bromide.

We compared the effects of 30-day treatments with fenoterol in low doses (4 x 100 mcg) and ipratropium bromide (4 x 40 mcg) on the lung function parameters (LFP), dyspnea and physical capacity of patients with severe chronic obstructive pulmonary disease (COPD) (FEV1 < 35% pred.) and analysed the individual response of patients to the administered therapy. The study included two groups of patients treated with fenoterol (n = 22) and ipratropium bromide (n = 22). The patients were matched by functional characteristics (age: 60 +/- 7 and 57 +/- 9 years; ATS Dyspnea Scale: 2.7 +/- 0.8 and 2.4 +/- 0.9; FEV1%: 25 +/- 7% and 23 +/- 6%; pO2: 62.4 +/- 5.3 mm Hg and 61.0 +/- 9.5 mm Hg; all values mean +/- SD). After 30 days of treatment we measured the lung function parameters (FEV1, FVC), dyspnea indices (ATS dyspnea scale, Borg scale) and the physical capacity of the patients (6-minute walking distance test). The results showed that in an open experiment fenoterol (4 x 100 mcg daily), unlike ipratropium bromide (4 x 40 mcg daily), cannot improve statistically and clinically significantly the lung function parameters, dyspnea and the physical capacity of the group as a whole. However, when the findings were assessed for each patient individually, 32% of the patients proved to have responded positively to the treatment. Therefore efficaciousness of fenoterol in low doses should be determined by assessing the lung function parameters, dyspnea and the physical capacity individually for each patient.

Adrenergic beta-Agonists↗
PubMed1999

Effect of CPAP on breathlessness perception in healthy subjects during methacholine induced bronchoconstriction.

Application of continuous positive airway pressure (CPAP) in asthmatic patients decreases breathlessness (B). The effect of CPAP on induced bronchoconstriction was studied in healthy subjects. The changes in B were related to changes in lung function indices. In nine healthy volunteers, males aged 20-27 years, acute bronchoconstriction was induced by inhalation of 1 to 128 mg/ml methacholine (M). CPAP (0.5 kPa) was then applied for 1 min. It was followed by inhalation of albuterol. Forced expiratory volume in 1 s (FEV1) and vital capacity (VC) were measured by spirometry and end expiratory lung level (EELL), to derive inspiratory capacity (IC), by inductive plethysmography. B was assessed by Borg scale. After the maximal concentration of M, FEV1 decreased by 14% (p < 0.01) as compared to the control values and Borg score (BS) increased to 2.4 (p < 0.01). In 7 out of 9 subjects we found a significant (p < 0.05) correlation between the changes in FEV1 and BS. BS decreased during CPAP (p < 0.01) and it further decreased significantly after albuterol. There was no correlation between the changes in IC and FEV1 during bronchoconstriction, or between IC and BS during CPAP. In conclusion, in healthy subjects with induced bronchoconstriction CPAP decreased significantly BS, which was further improved by inhalation of albuterol. B was related to changes in FEV1 but not in IC.

Adult↗
PubMed1998

Evaluation of external breathing in children living in a region with industrial pollution.

BACKGROUND: The changes in respiratory functions are among the most sensitive indicators available for the evaluation of the influence of air pollution on health. OBJECTIVE: The objective of the present study was to evaluate the respiratory functions of children from three schools situated at a different distance from the major sources of air pollution--an asbestos-cement plant, a fertilizer plant and a steam-power plant which utilize brown coal as a main source of energy. METHODS: Comprehensive functional investigation of breathing (FIB) was performed on 97 children from the town of Dimitrovgrad--mean age 10.4 +/- 0.1 years and height 145 +/- 0.6 cm (mean +/- Sx) in a special university medical center laboratory. The characterization of the degree of air pollution was based on the analysis of the mean yearly concentrations of particulate matter, sulfur dioxide, nitrogen dioxide, ammonia and hydrogen sulphide in the three zones of exposure in the town on the basis of the criteria outlined in the Uniform National System for Control of Air Pollution in Bulgaria. RESULTS: The mean yearly concentrations of particulate matter up to 0.19 mg/m3, of hydrogen sulphide--up to 0.07 mg/m3, of nitrogen dioxide--up to 0.025 mg/m3, of ammonia--up to 0.16 mg/m3, of hydrogen sulphide--up to 0.13 mg/m3 and lead aerosols--up to 0.00012 mg/m3 recorded at the different stations reached statistical significance at some of them. No significant differences were found in the values of lung function parameters of the healthy children from all three zones. MEF50% (94 +/- 2%) and the Single Breath Transfer Factor (TLCO = 93 +/- 1.5%) showed a tendency towards lower values. CONCLUSIONS: In the low-grade pollution that we found in the present study no significant differences were found in the lung function parameters of the children from the three regions.

Air Pollutants↗
PubMed1996

Airways obstruction, chronic expectoration, and rapid decline of FEV1 in smokers are associated with increased levels of sputum neutrophils.

BACKGROUND: Smoking may cause inflammation of the airways and impairment of lung function. To determine the relationship between the type and degree of airways inflammation and the decline in lung function, leucocytes in the sputum of smokers and ex-smokers were examined. METHODS: Forty six smokers and ex-smokers of median age 64 years (25%; 75% percentiles 62;66) with a smoking history of 40.1 (31.7;53) pack years were studied with lung function tests and a questionnaire at the end of a 15 year follow up period. Sputum was induced by inhalation of hypertonic saline and differential leucocyte counts were performed on cytospin preparations. RESULTS: Adequate sputum samples were obtained in 38 subjects (78%). The ratio of forced expiratory volume in one second (FEV1) to vital capacity (VC) was 67.1 (60; 72)% and the annual decline in FEV1 was 19.4 (12;30) ml/year. Subjects with airways obstruction (FEV1/VC < 63%) had more neutrophils (77 (50;86)%) than those without airways obstruction (60 (43;73)%). The percentage of neutrophils was also significantly greater (77 (62;85)%) in those with chronic expectoration than in those without expectoration (57 (45;75)%. Increased levels of neutrophils in the sputum were correlated with a rapid decline in FEV1 over the 15 year follow up period. CONCLUSIONS: Airways obstruction and chronic expectoration, as well as accelerated decline in lung function, are associated with increased numbers of neutrophils in the sputum of smokers and ex-smokers which suggests that neutrophilic inflammation of the airways may be involved in the pathogenesis of chronic obstructive pulmonary disease.

Cough↗
PubMed1996

Expiratory flow limitation during sleep in heavy snorers and obstructive sleep apnoea patients.

Inspiratory flow limitation (FL) during sleep has previously been reported both in obstructive sleep apnoea (OSA) patients and heavy snorers (HS). Recent results from this laboratory have shown the occurrence both of inspiratory and expiratory flow limitation during muscular relaxation in awake healthy subjects and OSA patients. In this study, we have investigated whether expiratory flow limitation occurs during sleep in heavy snorers and in patients with OSA. We studied four nonapnoeic, heavy snorers and five OSA patients. Airflow was measured with a pneumotachograph attached to a tight-fitting mask, and supraglottic pressure with a catheter placed at the supraglottic level. Scoring for flow limitation was achieved by visual inspection of 200 breaths recorded during sleep. About 20% of the respiratory cycles presented isolated inspiratory flow limitation. Approximately the same percentage was observed in heavy snorers and OSA patients. Isolated expiratory flow limitation was less frequently recorded. Coupled inspiratory and expiratory flow limitations were more numerous, especially in heavy snorers. We conclude that both in heavy snorers and obstructive sleep apnoea patients, inspiratory flow limitation is associated with expiratory flow limitation. This suggests that upper airway obstruction during sleep is both an inspiratory and expiratory event.

Adult↗