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Biomedical subjects

R Sergysels

Publications and source records attributed to R Sergysels.

At least 19 recordsLinked to original sources
PubMed1992

Relation between the bronchial obstructive response to inhaled lipopolysaccharide and bronchial responsiveness to histamine.

BACKGROUND: Bronchoconstriction has developed after inhalation of lipopolysaccharide in a dose of 20 micrograms in asthmatic patients and of 200 micrograms in normal subjects. This study set out to determine whether the bronchial response to lipopolysaccharide was related to non-specific bronchial responsiveness and atopy. METHODS: Sixteen subjects with a fall in specific airway conductance of 40% (PD40sGaw) after inhaling up to 900 micrograms histamine inhaled 20 micrograms lipopolysaccharide (from Escherichia coli type 026:B6) a week after bronchial challenge with a control solution of saline. The bronchial response over five hours was measured as change in FEV1 and area under the FEV1-time curve. RESULTS: FEV1 fell significantly more after lipopolysaccharide than after diluent inhalation, the difference in mean (SE) FEV1 being 4.6% (5.4%); response was maximal 60 minutes after lipopolysaccharide inhalation and lasted more than five hours. Histamine PD20FEV1 and PD40sGaw correlated with the fall in FEV1 after lipopolysaccharide inhalation. There was no difference in the proportions of responders and non-responders to lipopolysaccharide who were atopic. CONCLUSION: Lipopolysaccharide induced bronchial obstruction is associated with non-specific responsiveness but not with atopy.

Administration, Inhalation↗
PubMed1992

Inflammatory response to acute inhalation of endotoxin in asthmatic patients.

Inhalation of 20 micrograms endotoxins (from the membrane of Gram-negative bacteria) has been reported to induce a bronchial obstructive response in asthmatic subjects. The aim of the present study was to evaluate in asthmatic patients the possibility of an inflammatory response to inhaled endotoxins. Eight patients with mild asthma were submitted to bronchial challenge tests, in a single-blind trial, on Day 1 with control solution and on Day 7 with 20 micrograms endotoxin of Escherichia coli (026:B6). Local inflammatory response was indirectly evaluated by the degree of bronchial hyperresponsiveness (BHR) expressed as PD20 FEV1 histamine (the dose of histamine inducing a 20% decrease in FEV1) at 0, 6, 24, and 48 h and 7 days. Systemic inflammation was investigated by sequential blood determinations of total (and differential) white cells, complement anaphylatoxin C5a, interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-alpha), and C-reactive protein (CRP). A significant (p < 0.01) bronchial obstructive response was demonstrable 45 min after lipopolysaccharide (LPS) inhalation, lasting 5 h. Comparing the level of BHR after control inhalation, a significant (p < 0.05) increase in BHR was shown 6 h after LPS, partially normalized at 24 and 48 h. A short peak in TNF-alpha at 60 min (p < 0.05) and an increase in total white blood cells (p < 0.01) and neutrophil polymorphonuclear neutrophils at 360 min (p < 0.05) and of CRP at 24 and 48 h (p < 0.05 and p < 0.01) were significant. The other blood parameters did not change significantly.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Inhalation↗
PubMed1992

[Pneumopathy secondary to the improper use of a dust-removing spray].

We report the case of a 24 year-old woman who presented constitutional symptoms with dyspnoea on exertion accompanied by an interstitial pneumonitis in both lower lobes. The history revealed an excessive use of household dust-away cleansing spray. The diagnosis was established by bronchoalveolar lavage associated with appropriate steining. The early diagnosis is critical because of the progression to fibrosis and the risk of cancerisation.

Adult↗
PubMed1992

[Transthoracic lung punctures].

Transcutaneous needle aspiration (PTT) is a diagnostic technique which consists of biopsying pathological lung tissue using a needle (which in general is specifically designed for the purpose) which is introduced into the thorax transcutaneously. The target is lined up, either radioscopically or using a CT scanner and this enables the needle to be positioned in the centre of the lesion radiologically where one or more biopsies can be taken. According to the type and diameter of the needle these biopsies will enable a histological examination to be performed in addition to a cytological and bacteriological examination. This performance is particularly indicated in the final assessment of a periphery pulmonary nodule which is suspected of being neoplastic where bronchofibroscopy has been non contributory and where an immediate thoracotomy (diagnostic or therapeutic) is not recommended for one or other reason. When performed for this indication the technique often achieves a sensitivity of 90% with an average specificity of 98%. The diagnostic yield for benign tumours is less. It is always necessary to maintain a degree of vigilance in view of the risk of false negative or "benign" results. The complications exist above all of pneumothoraces which occur in 20-30% of cases and which will require a drain in 5-10% of cases. Haemorrhage and haemoptysis are less frequent but potentially fatal even in the absence of any coagulation disturbance.

Biopsy, Needle↗
PubMed1992

[Hyperventilation syndrome: current advances].

The hyperventilation syndrome has been described for half a century but clearly remains underdiagnosed. Its acute manifestation is easily diagnosed ("the tip of the iceberg") but its recognition in numerous subtle forms requires a particular degree of alertness on the part of the clinician ("the hidden part of the iceberg"). The incidence of this syndrome in the general population varies according to different authors as between 6-11% and may mimic diverse organic disorders. The physiological consequences of hyperventilation are reviewed as well as their contribution in the clinical picture. The aetiology of the syndrome and its links with organic pathology or psychiatric disturbances continues to be debated. Is hyperventilation the expression of abnormal respiratory function or a preferred manifestation of anxiety? This article discusses and reviews the variety of tests which enable the presumptive diagnosis to be confirmed. The response to the proposed treatments is generally excellent when one takes account of the numerous possible options. These include comportmental therapies such as respiratory re-education, the utilisation of betablockers and psychotrophic drugs or psychotherapy.

Bronchial Provocation Tests↗
PubMed1991

[Value of monitoring of tracheal respiratory sounds in the diagnosis of nocturnal respiratory dysrhythmias].

Twenty-six patients underwent a polysomnigraphic study allowing sleep staging and respiratory events scoring with the use of the oronasal flow, abdominal, thoracic and total displacement (Respitracet), and ear oximetry. Moreover the patients were also equipped with a tracheal microphone giving a power rectified envelope (sonospirogram). Eleven patients showed abnormal respiratory events that were scored by visual lecture using all respiratory parameters (excluding the sonospirogram) and were classified as obstructive central and mixed apneas-hypopneas. Periodic breathing was also appreciated. Detection of the same events was tried with the sonospirogram alone. The sonospirogram could accurately detect snoring and periodic breathing and finally central obstructive mixed apnea (the apneic index being well correlated: p less than 0.001 as well as the mean apnea duration: p less than 0.005). In contrast hypopneic events related to snoring could not be accurately appreciated. We conclude that a sonospirogram may be useful for the detection of abnormal respiratory events when used alone (screening) as when added to other respiratory signals.

Adult↗
PubMed1991

Domestic endotoxin exposure and clinical severity of asthma.

Endotoxins are potent pro-inflammatory substances present in several natural environments and in commercial house dust extracts. To investigate the possible effect of chronic endotoxin exposure on asthma, 28 patients with perennial chronic asthma (20 allergic to house dust mite and eight intrinsic asthmatics) were evaluated during a 4-month period (lung function, clinical and immunological criteria). At the same time, two house dust samples were collected from each patient's home to determine total house dust weight (mg/m2), endotoxin concentration and house dust mite antigen content (evaluated indirectly by guanine content with HPLC method). The mean (+/- s.d.) endotoxin concentration, as measured by quantitative Limulus assay was 2.59 (+/- 3.41) ng/mg house dust, ranging from 0.12 to 20 ng/mg. The mean guanine content was 0.13 (+/- 0.16) mg/100 mg house dust. There was no correlation between endotoxin and house dust mite concentrations. Patients were compared according to the low or high grade exposure to dust, endotoxins and guanine. Compared with patients with low grade (less than or equal to 5.6 ng/ml) exposure, subjects exposed to high endotoxin concentrations (greater than 5.6 ng/ml) showed a significant increase in dyspnea (median 2.6 vs 3.3; P less than 0.05) and treatment (median 14 vs 44.3; P less than 0.01) scores, oral corticosteroid (median 0.0 vs 13.5 mg/24 hr; P less than 0.01) and beta 2-mimetics (median four vs eight puffs/day; P less than 0.01) intake, and a significant decrease in FEV1/FVC (median 84.5 vs 67% of predicted value; P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

[Respiratory patterns induced by bent posture in COPD patients].

Three body positions were studied in order to determine their influence on the respiratory pattern in 7 subjects with chronic airflow obstruction. The positions were sitting lying back (AR), sitting with the trunk leaning forwards (AP) and standing with the trunk leaning forwards (DP). Compared to sitting lying back, sitting in the forward position favoured diaphragmatic improvement and improved the length/tension relationship of the diaphragmatic fibres and of its mechanical coupling with the thoracic cage; as a result the diaphragm took a more important part in the overall inspiratory effort thus relieving the thoracic inspiratory muscular effort. In relation to AR, the standing, leaning forward (DP) increased the end expiratory level and gave rise to the development of active expiration. This change in the usual respiratory manner enables the diaphragm to benefit on inspiration from the help bought by the restoration of the potential energy stored up in the respiratory system during the course of expiration.

Evaluation Studies as Topic↗
PubMed1991

[Contribution of polysomnography in the assessment of patients with chronic obstructive bronchopneumopathy].

15 COPD patients underwent a polysomnographic study demonstrating poor quality of sleep, a mean of SAO2 of 88.8 +/- 3.9% and a apneic-hypopnea index (AHI) of 5.7 +/- 11.8. AHI was higher in sleep stages I and II than in REM sleep. SAO2 showed a progressive drop when going from an awake stage to REM sleep. Respiratory events responsible for the most important desaturation where mostly observed in REM sleep and corresponded in 8 patients to obstructive events (overlap syndrome). The lower mean SAO2 in REM probably explains the best the importance in desaturation related to the respiratory events (Hb dissociation curve). Ear oximetry recordings however interesting are not able to quantify and recognise correctly the respiratory events. Therefore a polysomnographic study remains necessary in order to diagnose adequately the overlap syndrome.

Electrophysiology↗
PubMed1990

Cyclic haemodynamic and arterial blood gas changes during Cheyne-Stokes breathing.

A 74-year-old patient presented with congestive heart failure and continuous periodic breathing. Left ventricular ejection fraction was 20% and the lung-to-brain circulation time was prolonged to 35 s. We report on the phasic changes of the patient's arterial blood gas tensions and on the periodic fluctuations of pulmonary artery pressures and cardiac output that we observed during Swan-Ganz catheterisation.

Aged↗
PubMed1990

[The value of a visual score of dyspnea in the functional follow-up of asthma patients].

6 severe asthmatic patients were followed for 24 hours using a visual analogue score of dyspnoea and by studying the airway resistance. Their treatment consisted either of two inhalations of placebo or of two inhalations of fenoterol every 5 hours. It appeared that there was only a correlation between the dyspnoea score and respiratory function score for the largest variations of resistance induced by inhalation of sympathicomimetics. The inverse was that altered function offering only small fluctuations was not correlated with a sensation of dyspnoea.

Adult↗
PubMed1979

Low frequency breathing at rest and during exercise in severe chronic obstructive bronchitis.

The effect of low frequency breathing compared with spontaneous breathing was examined at rest and during exercise (40 watts) in 12 patients suffering from severe chronic obstructive bronchitis. At rest low frequency breathing improved significantly the alveolar ventilation and the tensions of oxygen and carbon dioxide in the arterial blood. There was no significant change in ventilation minute volume. During exercise low frequency breathing significantly decreased ventilation minute volume, and there was no significant improvement in gas exchange. The decrease in ventilation during low frequency breathing at 40 watts compared with spontaneous breathing at the same lung volume was due to expiratory flow limitation. The findings suggest that this technique may impair exercise tolerance in patients with severe chronic obstructive bronchitis.

Bronchitis↗
PubMed1979

Functional evaluation of a physical rehabilitation program including breathing exercises and bicycle training in chronic obstructive lung disease.

20 patients suffering from chronic obstructive lung disease (COLD) were submitted to a 6-month rehabilitation program including breathing exercises only (A) or coupled with bicycle training (B). Functional results obtained at rest were the following: for A: nonsignificant changes in FRC, RV, FEV1, Raw, Pa O2, pH, Pp, VO2 max SL but significant changes (p less than 0.05)for TLC (+ 214 cm3), VC (+ 171 cm3), DL CO (+ 1.79 ml), Pa CO2 (-2.9 mm Hg). For B: similar changes as for A with additional significant changes in PaO2 (+ 7.4 mm Hg) VO2 max SL (+ 250 ml) and Pp (-4 mm Hg). These results, although minimal, are attributed to improved respiratory muscle strength and improved alveolar ventilation. Exercise training adds an increased ability to sustain higher loads.

Breathing Exercises↗
PubMed1978

Effect of ventilation with different gas mixtures on experimental lung air embolism.

In six anesthetized, curarized and mechanically ventilated dogs, air was infused via a jugular vein at 0.1 cm3/kg/min for 25 min. This induced a progressive increase in pulmonary artery pressure (Pap) while arterial PO2 (PaO2) and end tidal PCO2 (PETCO2) decreased. Systemic arterial pressure, dynamic lung compliance and total pulmonary resistances were not affected. Changes tended to plateau by 20 min with a peak increase in Pap of 80 +/- 13% and decrease in PaO2 and PETCO2 of 22.2 +/- 2.8% and 14.5 +/- 2.1% respectively. When embolization was stopped these values returned to control levels within 30 min. During air infusion (at 20 min) some dogs were switched from ventilation with air to ventilation with the following gas mixtures: SF680%-O220%, He80%-O220%, N2O80%-O220%. During the final 5 min of air infusion. He and, to a greater extent, N2O breathing results in an immediate and marked further increase in Pap and decrease in PaO2 and PETCO2. In contrast SF6 produced rapid improvement in these parameters with return to near control levels. The recovery time after stopping infusion was greatly shortened with SF6 but was unaffected by He or N2O. These results are explained by different rates of gas transfer between the intravascular bubbles and the various alveolar gases. These findings show that ventilation with SF6 results in marked improvement in the gas exchange abnormalities produced by air embolism.

Animals↗