Respiratory medicine
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Respiratory medicine · Mar 1998
Leukocyte counts in hypertonic saline-induced sputum in subjects with occupational asthma.
We measured markers of eosinophilic inflammation in the blood and in the sputum induced by hypertonic saline (HS) inhalation of 24 subjects with occupational asthma who were still exposed to high molecular weight compounds (HMWCs, n = 8) or to low molecular weight compounds (LMWCs, n = 16); all subjects were symptomatic and showed bronchial hyperresponsiveness to methacholine at the time of study. Sputum cell counts were also measured in 14 normal subjects and in 24 subjects with non-occupational asthma with asthma severity similar to that of occupational asthmatics. Both occupational and non-occupational asthmatic subjects showed higher neutrophil percentages in HS-induced sputum than normal subjects, asthmatics with LMWC-induced asthma showing the highest values. ⋯ A significant correlation between sputum eosinophil percentages and bronchial hyperresponsiveness to HS was observed. Despite a similar degree of functional abnormalities, subjects with asthma due to LMWCs and still exposed to the occupational sensitizer showed a lower degree of eosinophilic inflammation and a higher degree of neutrophilic inflammation in the airways than subjects with occupational asthma due to HMWCs or non-occupational asthmatics. Furthermore, sputum eosinophil counts detect, better than blood indices, the degree of airway inflammation in both occupational and non-occupational asthma.
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Respiratory medicine · Mar 1998
Randomized Controlled Trial Clinical TrialPulse oximetry at fibre-optic bronchoscopy in local anaesthesia: indication for postbronchoscopy oxygen supplementation?
The requirement for supplementary oxygen (O2) after fibre-optic bronchoscopy (FOB) was evaluated by means of pulse oximetry in 34 patients (19 men) of median age 62 years (range 28-85) who had had a diagnostic FOB. The patients were allocated at random into two groups, each of 17 persons, which were comparable concerning sex, age and the dose of benzodiazepine (diazepam tablets 10 mg 1 h before FOB and midazolam 2-5 mg i.v. during FOB) used for premedication. Patients in group 1 had lower pulmonary function (FEV1, FVC as a percentage of predicted values) than patients in group 2 (P < 0.02). ⋯ The cumulated duration of hypoxaemia after FOB was a median of 30 s (range 0-7140) in group 1 and a median of 0 s (0-156) in group 2 (P < 0.0001). Impaired lung function (FEV1 < 75% of predicted value) was a risk factor for hypoxaemia. Postbronchoscopy, O2 supplement should be administered to sedated patients with impaired lung function until the patients have fully recovered.
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Respiratory medicine · Mar 1998
Comparative StudyTranscutaneous monitoring of blood gases: is it comparable with arterialized earlobe sampling?
Researchers are increasingly looking for reliable non-invasive methods of assessing blood gas concentrations, and several new techniques have recently become available. Values derived using arterialized earlobe samples have been found to be comparable with conventional arterial samples, and recent studies have compared transcutaneous blood gas analysis with the traditional arterial samples and found a reasonable level of agreement in particular for the partial pressure of carbon dioxide. There are no data comparing oxygen and carbon dioxide partial pressures (pO2, pCO2) derived from arterialized samples with one of the newer transcutaneous techniques. ⋯ I.) between transcutaneous and earlobe values 0.25 kPa (-0.004, 0.5 kPa)], but not for pO2 [1.71 kPa (0.35, 3.07 kPa)]. Similarly, the limits of agreement were narrow for pCO2 compared to those for pO2 (-0.98, 1.47 kPa and -6.44, 3.02 kPa respectively). We conclude that transcutaneous measurement of pCO2 using the TINA is acceptable in the research setting, whereas assessment of pO2 cannot reliably be made using this technique.
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Respiratory medicine · Mar 1998
Plasma levels of von Willebrand factor antigen in acute bronchitis and in a normal population.
von Willebrand factor (vWF) is a large glycoprotein secreted predominantly by endothelial cells in both the systemic and pulmonary circulations and has a central role in the formation of the platelet plug. It has been put forward as a possible marker of endothelial cell injury, but is not ideal in that it is not specific for either the pulmonary or systemic circulation and may be released as part of the acute phase response from otherwise healthy endothelial cells. We undertook two studies (i) to assess within-subject to assess within-subject variation in plasma von Willebrand factor antigen (vWF:Ag) levels over time and to assess between-subject variation in a healthy patient population, and (ii) as part of a descriptive study of acute bronchitis, to assess whether plasma vWF:Ag levels altered in such a common and minor insult. ⋯ We conclude that there is relatively little variation in an individual's plasma vWF:Ag level but that levels increase significantly with age. The observed elevation occurring with acute bronchitis is a true phenomenon; the absence of an associated acute phase response suggests that endothelial cell injury is the mechanism for the rise. These observations are important in the context of vWF as a marker of endothelial cell damage, as a common and supposedly minor insult such as acute bronchitis may markedly raise plasma levels.