PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Airway Obstruction”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1976

Dead space ventilation in normal children and children with obstructive airways diease.

Anatomical dead space was measured in 72 normal children aged from 5 to 16 years, using the single breath method. There was a linear increase in this measurement with height, weight, and end-inspiratory lung volume. Physiological dead space was measured in 52 normal children using the Bohr equation and substituting a rebreathing PCO2 for alveolar PCO2. There was a parallel increase in this measurement with height, weight, and end-inspiratory lung volume. The difference between the two dead space measurements constitutes the alveolar dead space and was constant over the whole age range at 45 +/- 22 ml. The ratio of physiological dead space to tidal volume was 33-6 +/-4-6% and was unaltered by age or change in lung volume. The effect of airways obstruction on the dead space volumes was studied in 36 children with asthma and 28 with cystic fibrosis. Physiological dead space increased with increasing airways obstruction. Anatomical dead space remained constant in spite of marked increases in lung volume associated with the airways obstruction.

Adolescent↗
PubMed1976

Density-dependence of maximal expiratory flow rates before and after bronchodilators in patients with obstructive airways disease.

1.Gas-density-dependence of maximal expiratory flow rats (V max), defined as the ratio of V max. while breathing helium/oxygen (80:20) to V max. while breathing air at the same lung volume, was examined in relation to other measurements of airways obstruction in patients with obstructive airways disease before and after administration of bronchodilators. 2. Seventeen patients showed a 45% or greater increase in specific conductance (sG aw) after bronchodilator therapy (group A) and thirteen patients demonstrated a lesser response (group B). 3. Before the administration of bronchodilators, the degree of obstruction in two groups was not different as measured by lung volumes, sG aw, forced expiratory volume in 1 s, and flow rates high in the vital capacity; yet the maximal mid-expiratory flow rate and the degree of density-dependence were significantly lower in group B. 4. After bronchodilators, both groups of patients showed significant improvements in sG aw, flow rates and lung volumes. However, group A patients showed a signifcant increase in density-dependence whereas group B patients did not. 5. Increased density-dependence after bronchodilators in the group A patients was associated with an increase in the computed resistance of the upstream segment with air and a decrease in resistance with helium/oxygen. These changes could be explained by a more mouthward of equal pressure points, and therefore a further increase in the relative contribution of the larger density-dependent airways to limitation of flow. 6. The fact that density-dependence was not altered after bronchodilators in the group B patients suggests that the site of limitation of flow did not change appreciably. The shift in the pressure-flow curve for the upstream airways was such that the computed resistance of these airways fell. Thus it appears that the airways comprising the upstream segment were dilated.

Airway Obstruction↗
PubMedDate not supplied

Chronic obstructive airway disease in pneumoconiosis in comparison to chronic obstructive airway disease in non-dust exposed workers.

Many types of dust, including cigarette smoke, cause an impairment of lung function. This lung function impairment does not affect working capacity provided the dust is not fibrogenetic. Quartz, normally present in coal mine dust in concentrations between 2 and 10% is claimed to be responsible for coal workers' pneumoconiosis (CWP) by some writers. However the evidence is conflicting and firm conclusions cannot be drawn at present. From the clinical point of view CWP is characterized by an increased airway resistance. All correlations between airway resistance, arterial oxygen and carbon dioxide pressure and intrathoracic gas volumes (IGV) in patients having CWP and obstructive airway disease are similar to those in non-dust exposed patients with obstructive ariway disease. Patients with CWP, at equivalent values of airway resistance have smaller mean values of IGV. The relationship between arterial oxygen pressure and pulmonary arterial pressure is the same in patients with CWP and obstructive airway disease as in patients with chronic obstructive airway disease but without CWP. The effect of therapy in CWP with obstructive airway disease corresponds very well to that seen in patients without CWP.

Adolescent↗
PubMed1975

Comparison of the cardiopulmonary effects of subcutaneously administered epinephrine and terbutaline in patients with reversible airway obstruction.

The cardiopulmonary effects of epinephrine and terbutaline were compared in a doubleblind crossover study in 23 subjects with chronic obstructive airway disease. On each of three days each subject received a single subcutaneous dose of saline, 0.25 mg of epinephrine or 0.5 mg of terbutaline. Treatment with epinephrine produced significant increases in forced vital capacity (FVC), forced expiratory volume in one second (FEV-1), maximal expiratory flow rate (MEFR) and maximal mid-expiratory flow (MMEF). Terbutaline caused even more pronounced increases in all four parameters and exhibited a longer duration of action. Neither drug altered arterial pH, arterial oxygen pressure (PaO-2), or arterial carbon dioxide pressure (PaCO-2). With regard to cardiovascular effects, no alterations in either systolic or diastolic pressure were observed. Administration of epinephrine and terbutaline caused statistically significant increases in heart rate. The effect of terbutaline was more pronounced that that of epinephrine. In addition, terbutaline caused a heart rate-related depression of the T-wave of the lead 2 ECG. Neither drug altered any of the hematologic, hemochemical or urinary parameters monitored before and after treatment. Side effects were seen in eight subjects after administration of saline solution, in 13 subjects after epinephrine and in 19 subjects after terbutaline. None of these side effects was considered clinically serious and none required treatment. It is concluded from this study that subcutaneously administered terbutaline is a more effective bronchodilator than epinephrine.

Adult↗
PubMed1979

The value of atropine in the documentation of reversible airways obstruction.

Thirteen randomly selected outpatient asthmatics were treated with nebulized atropine sulfate, isoproterenol and the combination of these drugs in a randomized double-blind trial. Sequential pulmonary function parameters, cardiovascular changes and side effects were monitored over a 60-minute period following drug administration. Both atropine and isoproterenol produced significant and equivalent improvement in mean forced expiratory flow rates; the combination of drugs produced significantly greater improvement at each time interval without producing significant cardiovascular changes or side effects. Four patients failed to show clinically significant increases in expiratory flow rates following isoproterenol alone; two of these four improved following atropine alone, while two improved only when given the combination of drugs. The addition of an anti-cholinergic agent may provide a more precise assessment of reversibility of obstructive airways disease in the individual patient.

Adult↗
PubMed1977

Gas exchange and arterial blood gas tensions to terbutaline sulfate in older patients with reversible airway obstruction.

Ten patients 55 years and older, known to have chronic obstructive airway disease with reversible component and who had required daily sympathomimetics for many years, were studied. At a clinically stable state in a sitting position, spirometry, ventilation, gas exchange, diffusion and arterial blood gas determinations were performed before and 10, 30, 60 and 120 minutes after administration of 0.5 mg of terbutaline sulfate by inhalation. Although changes were small, significant improvement in FEV1 remained even two hours after inhaling terbutaline. Increase of conducting airways reflected an increase of dead space for 120 minutes. Early rise of alveolar-arterial oxygen tension (PAO2-PaO2) with decreased arterial oxygen tension was observed. This was a transient phenomenon and not severe enough to warrant immediate therapy. No significant EKG or blood pressure changes were noted throughout the study. It appears that terbutaline, an effective long acting bronchodilator, can be safely administered to older patients with bronchospasms.

Aged↗
PubMed1976

Radionuclide imaging of airway obstruction following assisted ventilation.

Radioaerosol lung scintigraphy was performed in five infants in whom obstructive airway complications developed following assisted ventilation. These studies suggest that a primary functional defect was obstruction to airflow at the level of the major airways, which occurred during expiration. Perfusion lung scintigraphy showed areas of diminished or redistributed pulmonary blood flow, which, like the results of the radioaerosol scintigraphic studies, are findings often associated with adult chronic obstructive pulmonary disease.

Airway Obstruction↗
PubMedDate not supplied

Physiologic differentiation of upper and lower airway obstruction.

Usual lower airway obstruction and fixed upper airway obstruction can be differentiated physiologically by means of the flow-volume curve. Normally, maximal flow decreases nearly linearly as lung volume decreases during expiration. In lower airway obstruction, this decrease is greatest at the beginning of expiration resulting in a curve that is concave upward. In fixed obstruction (stenosis) flow is constant throughout the initial part of forced maximal expiration and throughout virtually all of inspiration. This results in a plateau or flat curve which is characteristic and different from the curve in obstruction of lower airways. Cases in which this differentiation is clinically important are discussed.

Adult↗
PubMedDate not supplied

Reduced adenosine 3',5'-cyclic monophosphate levels in patients with reversible obstructive airways disease.

1. Patients were grouped into categories of 'no airways disease', 'obstructive airways disease without response to bronchodilator' and 'obstructive airways disease with bronchodilator responsiveness'. 2. Cyclic nucleotides were assayed in specimens of lung tissue that were excised during surgery. 3. Reduced levels of adenosine 3',5'-cyclic monophosphate (cyclic AMP) were found in pulmonary tissue obtained from patients with reversible obstructive airways disease, lending support to the beta-adrenergic theory of asthma.

Airway Obstruction↗
PubMed1975

Effect of fiberoptic bronchoscopy on respiratory performance in patients with chronic airways obstruction.

Lung volumes, airway resistance, expiratory flow rates, distribution of ventilation, and arterial blood gases were measured before and after fiberoptic bronchoscopy in 13 patients with moderately severe chronic airways obstruction and in 10 healthy non-smoking controls. Arterial blood gases were also monitored serially during the procedure. Arterial oxygen tension (Pao2) fell during fiberoptic bronchoscopy in both patients and controls whereas arterial carbon dioxide tension and pH remained unchanged. Control subjects had no change in lung mechanics after fiberoptic bronchoscopy. However, the patients consistently developed increased airway obstruction after fiberoptic bronchoscopy. Within 24 hours after bronchoscopy lung function in the patients returned to baseline values, except for the residual volume which remained abnormally high. The topical application of lignocaine (Lidocaine) for local anesthesia before fiberoptic bronchoscopy produced no effect on lung mechanics in nine patients and 10 controls, but Pao2 decreased in both the patient and control groups. These results indicate that fiberoptic bronchoscopy consistently inpairs lung mechanics and gas exchange in patients with chronic airways obstruction but that the impairment is mild and reversible. Lignocaine administration as well as the intubation procedure contribute to the fall in Pao2 which occurs both in the patients and in subjects without pre-existing lung disease.

Adult↗
PubMed1976

Aerosol penetrance: a sensitive index of peripheral airways obstruction.

Early injury of the small airways has been demonstrated in asymptomatic smokers. Ventilatory tests including the maximum midexpiratory flow rate and closing volume have been useful in clinical detection of small airways disease in symptomatic subjects. In the present study, airway "obstruction" was assessed aerodynamically by gamma camera measurements of chest radioactivity following the inhalation of 131I-labeled aerosol (aerodynamic mass median diameter 3 mum). Studies were performed in normal subjects, asymptomatic smokers, and patients with chronic obstructive lung disease. An aerosol penetrance index (AeP) was devised from determinations which involved 1) an analysis of central (inner zone) and peripheral (outer zone) deposition of aerosol in the lung and 2) a ratio of initial counts to 24-h counts in the periphery (outer zone) of the lung. AeP values were 41.5 +/- 11.5 for the normal group, 20.9 +/- 7.6 for the smoker group, and 10.6 +/- 5.2 for the subjects with chronic obstructive airway disease. AeP was significantly reduced in the smokers indicating that the AeP is a sensitive index of early peripheral airways obstruction.

Aerosols↗
PubMed1975

Rhinorrhea with airway obstruction.

Life endangering airway obstructions have many facets and causes. Rhinorrhea is a symptom whose etiology may be overlooked if an immediate crisis of airway obstruction is present. Unless the cause for the obstruction or rhinorrhea is investigated it may go undetected and continue to present further problems for the patient. This is especially true of infants under six months of age who are obligate nasal breathers. The following are three cases representing this problem.

Adenoidectomy↗
PubMed1977

Relationship between pulmonary embolism, airway obstruction and hypersensitivity of the airways in dogs: influence of partial vagus nerve blockade.

Experiments in dogs showed an increase in deltaPoes/100 ml TV after embolization which returns to normal after blocking the vagus nerves, indicating an increase in airway resistance. A marked sensitization to ACh inhalation by embolism with both blood clots and glass beads was demonstrated. This hypersensitivity is vagus-dependent.

Acetylcholine↗
PubMed1979

[Comparative examination of theophylline-serum-concentrations and bronchospasmolytic effect of cholintheophyllinate (euspirax) and theophyllin-aethylendiamine (euphyllin retard) in patients with obstructive airway diseases (author's transl)].

12 patients with obstructive airway diseases were given a single oral dose of 400 mg resp. 600 mg Cholintheophyllinate (Euspirax) and 350 mg Theophyllin-Aethylendiamine (Euphyllin retard). In an intra-individual comparative study the theophylline-serum-concentrations and the bronchospasmolytic effects of both drugs have been checked over a period of 12 hours. A very good resorption and the highest mean blood levels of 9,13 +/- 2,88 mg/1 resp. 12,11 +/- 2,55 mg/1 resulted from Cholintheophyllinate 2 hours after application. The effect on the lung function parameters was most expressed 2 to 4 hours after application of this drug and correlated well with the theophylline-blood-levels. The higher dose of Euspirax was followed more frequently by side effects. 2, 4 and 12 hours after application of Euphyllin retard the serum-concentrations were strikingly low. The mean values were 2,04 +/- 1,22 mg/l, 3,00 +/- 2,18 mg/l resp. 3,38 +/- 2,01 mg/l. In spite of the low blood levels a significant improvement of the lung function parameters could be noticed after 4 to 6 hours. The qualities of both drugs as to their bioavailability and effect on airway obstruction shall be examined by means of another comparative study.

Adult↗