Respiratory medicine
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Respiratory medicine · May 2000
Use of pleural fluid C-reactive protein in diagnosis of pleural effusions.
The aims of the study were to assess whether C-reactive protein (CRP) is a sensitive marker for discriminating between transudative and exudative and pleural effusions to evaluate whether it can be used to distinguish inflammatory pleural effusions from other types of effusion. Pleural fluid and serum CRP levels were obtained in 97 patients with pleural effusion, using an immunoturbidimetric method (Olympus AU-600 autoanalyser). We compared CRP levels between transudates and exudates, inflammatory effusions and other types of effusion. ⋯ Pleural fluid CRP levels > 30 mg l(-1) had a high sensitivity (93.7%) and specificity (76.5%) and a positive predictive value of 98.4%. In the differential diagnosis of pleural effusions, higher CRP levels may prove to be a rapid, practical and accurate method of differentiating parapneumonic effusions from other exudate types. Although the high level of CRP obtained in the exudate group may be due to the number of patients with parapneumonic effusion who were included, the pleural CRP level may also be helpful in discriminating between exudative and transudative pleural effusions.
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Respiratory medicine · Apr 2000
In vivo efficacy of heated and non-heated humidifiers during nasal continuous positive airway pressure (nCPAP)-therapy for obstructive sleep apnoea.
Upper airway dryness is a frequent side-effect of nasal continuous positive airway pressure therapy (nCPAP) in obstructive sleep apnoea (OSA). In this situation, heated or non-heated passover humidifiers are often added to the nCPAP-therapy. The efficacy of these two modes in terms of increasing the absolute humidity of the inspired air in vivo has so far not been established. ⋯ These results were, however, obtained under laboratory conditions, and therefore cannot be translated unreservedly to the situation represented by long-term CPAP-treatment. Furthermore, it is possible that the smaller humidification capacity of the non-heated humidifiers may still suffice to meet the requirements of clinical use in terms of effectively preventing dry airways under CPAP treatment. This point, however, needs further investigation on the basis of long-term clinical studies.
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Respiratory medicine · Apr 2000
Use of transcutaneous oxygen and carbon dioxide tensions for assessing indices of gas exchange during exercise testing.
The slow response characteristics of the combined transcutaneous electrode have been viewed as a major disadvantage when compared with other types of non-invasive assessment of gas exchange during exercise testing. We have previously shown that by using the highest recommended temperature of 45 degrees C to reduce response times, and combining this with an exercise protocol of gradual work load increments, that this allows changes in arterial blood gases to be closely followed by transcutaneous values. In the present study we have validated the use of a transcutaneous electrode for estimation of alveolar-arterial oxygen gradient (AaO2) and dead space to tidal volume ratio (V(D)/V(T)) during exercise, against values calculated from direct arterial blood gas analysis. ⋯ The findings of this study suggest that estimation of parameters of gas exchange using transcutaneous values during exercise testing is reliable, provided the electrode is heated to a slightly higher temperature than usual and the work load increments are gradual, allowing for the latency in the response time of the system. This system allows the assessment of the contribution of ventilation/perfusion inequality to breathlessness on exertion in patients, provided an initial arterial or ear lobe capillary sample is obtained for calibration purposes. This technique is particularly valuable in patients undergoing repeat exercise tests as it circumvents the need for arterial cannulation.
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Respiratory medicine · Mar 2000
The economic impact of asthma and chronic obstructive pulmonary disease (COPD) in Sweden in 1980 and 1991.
This study was carried out to estimate the direct and indirect costs associated with asthma and chronic obstructive pulmonary disease (COPD) in Sweden in 1980 and 1991, and to identify trends in the use of outpatient care, drugs and inpatient care, and the development of temporary morbidity, permanent disability and mortality for asthma and COPD. Routinely published administrative and population data were used to estimate the costs of asthma and COPD, and these figures were compared to corresponding estimates and trends for all respiratory diseases as well as for all diseases. Asthma and COPD each accounted for about SEK 3 billion, together roughly 2% of the economic cost of all diseases. ⋯ During the 1980s, the cost of drugs and out-patient care increased for both diseases. The cost of inpatient care for asthma decreased, whereas that for COPD increased. This study shows that asthma therapy has changed from inpatient to ambulatory care in Sweden, while the treatment of COPD to a higher degree still is based on inpatient care.
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Respiratory medicine · Mar 2000
Prevalence and mechanisms of diurnal hypercapnia in a sample of morbidly obese subjects with obstructive sleep apnoea.
It is well known that obstructive sleep apnoea is especially frequent in the morbidly obese. In these subjects diurnal chronic hypercapnia, whose mechanism is still debated, may be present. Our study was performed to evaluate the prevalence and the mechanism of diurnal hypercapnia in the morbidly obese affected by obstructive sleep apnoea. ⋯ The comparison among the three subgroups, in which we divided the morbidly obese subjects, shows that those with hypercapnia and obstructive sleep apnoea had significantly more important ventilatory restrictive defects [forced vital capacity (FVC)% of pred 73.27+/-14 81 vs. 82.37+/-16.93 vs. 87.25+/-18.14 respectively; total lung capacity (TLC)% of pred 63.83+/-16.35 vs. 79.11+/-14.15 vs. 87.01+/-10.5], a significantly higher respiratory disturbance index (RDI 46.34+/-26.90 vs. 31.79+/-22.47 vs. 4.98+/-3.29) a longer total sleep time with oxyhaemoglobin saturation<90% [total sleeptime (TST)SaO2<90% 63.40+/-33.86 vs. 25.95+/-29.34 vs. 8.22+/-22.12] and a lower rapid eye movement (REM) stage (9.5+/-1.2 vs. 14.0+/-0.9 vs. 17.05+/-1.2) than normocapnic subjects with obstructive sleep apnoea or subjects without obstructive sleep apnoea. The best model to predict PaCO2 resulted from a combination of TSTSaO2<90% (r2 = 0.22, P<0.001), forced expiratory volume in 1 sec (FEV1)% of pred (r2 = 0.09, P<0.01), FVC % of pred (r2 = 0.075, P<0.01). In conclusion our study suggests that diurnal hypercapnia is frequently associated with obstructive sleep apnoea in the morbidly obese without chronic obstructive pulmonary disorder (COPD) and that ventilatory restriction and sleep related respiratory disturbances correlate to diurnal hypercapnia.