Effect of inhaled methacholine on gas mixing efficiency

1988 ◽  
Vol 74 (2) ◽  
pp. 187-192 ◽  
Author(s):  
F. Langley ◽  
K. Horsfield ◽  
G. Burton ◽  
W. A. Seed ◽  
S. Parker ◽  
...  
Keyword(s):  
Pulmonary Function ◽  
Dead Space ◽  
Pulmonary Function Tests ◽  
Statistical Significance ◽  
Mixing Efficiency ◽  
Nitrogen Washout ◽  
Single Breath ◽  
Function Tests ◽  
In Series ◽  
Airways Resistance

1. Pulmonary function tests, including alveolar mixing efficiency by the single-breath and multi-breath methods, and ventilation scans were performed on 16 volunteer subjects. The tests were repeated after the inhalation of a methacholine aerosol in sufficient dosage to increase airways resistance. 2. After inhalation of methacholine there was a significant fall in mean series dead space of 31 ml (P < 0.05), and mean multi-breath alveolar mixing efficiency fell from 68% to 36% (P < 0.001), a fall occurring in all subjects. Mean single-breath alveolar mixing efficiency measured on the first breath of the nitrogen washout fell from 76% to 70%, but this change did not reach statistical significance (0.1 > P > 0.05). 3. In eight of the subjects, technically adequate lung scans and pulmonary function tests were obtained both before and not more than 30 min after methacholine inhalation. In seven there were obvious visible defects on the ventilation scans, and in five of these the computer-calculated underventilation score became abnormal. 4. Thus inhalation of methacholine causes maldistribution of ventilation, a fall in alveolar mixing efficiency and a fall in series dead space, presumably brought about by bronchoconstriction. The parallel component of this maldistribution of ventilation, as judged by 81mKr ventilation scanning, does not of itself seem to be sufficient to explain the fall in alveolar mixing efficiency, and therefore a degree of diffusion limitation is probably involved as well.

Small airway evaluation in three subjects with alpha-1 antitrypsin deficiency without diagnosed lung disease

2021 ◽  
Vol 14 (3) ◽  
pp. e239146
Author(s):  
Thais Ferrari da Cruz ◽  
Rogério Rufino ◽  
Agnaldo Lopes ◽  
Cláudia Henrique Costa
Keyword(s):  
Pulmonary Function ◽  
Pulmonary Function Tests ◽  
Genetic Disorder ◽  
Early Investigation ◽  
Small Airways ◽  
Nitrogen Washout ◽  
Function Tests ◽  
Antitrypsin Deficiency ◽  
Alpha 1 Antitrypsin Deficiency ◽  
Alpha 1 Antitrypsin

We describe three cases of female subjects (aged 16, 44 and 41 years) with no respiratory symptoms, who have alpha-1 antitripsyn mutation (PiSZ, PiZZ and PiZZ) and who performed traditional pulmonary function tests and the single breath nitrogen washout test. They still did not have chronic obstructive pulmonary disease (COPD) or any identifiable change in traditional pulmonary function tests but already have change in nitrogen washout tests. Alpha-1 antitrypsin deficiency is a genetic disorder associated with early-onset COPD. There is evidence that although patients who have well-preserved FEV1 may already have signs of emphysema associated with symptoms. Therefore, the nitrogen washout test is considered to have more sensitive outcomes than other pulmonary function tests for early investigation of small airways disease and could allow the monitoring pulmonary function and evaluating of therapeutic decision.

Effect of Atropine on Alveolar Gas Mixing in Man

1982 ◽  
Vol 62 (5) ◽  
pp. 549-551 ◽  
Author(s):  
W. Kox ◽  
F. Langley ◽  
K. Horsfield ◽  
G. Cumming
Keyword(s):  
Tidal Volume ◽  
Dead Space ◽  
Normal Subjects ◽  
Acute Effect ◽  
Tidal Mixing ◽  
Mixing Efficiency ◽  
Normal Male ◽  
Gas Mixing ◽  
Nitrogen Washout ◽  
In Series

1. Atropine is known to diminish broncho-motor tone. In order to investigate the acute effect of atropine on respiration and alveolar gas mixing, a dose of 2.4 mg was given intravenously. 2. Ten normal male volunteers were each studied three times with a nitrogen washout method, once before administration of atropine and then 20 min and 60 min thereafter. 3. After the administration of atropine there was a reduction in tidal volume, a slight increase in frequency of respiration and an increase in series dead space. The tidal mixing volume showed a fall of 25%. In spite of the reduced alveolar dead space the effective mixing volume fell by 29%. Multi-breath alveolar mixing efficiency fell by 3.5%. 4. Multi-breath alveolar mixing efficiency was found to be less with smaller tidal mixing volumes, a fall of 518 ml in the latter causing a reduction of 17.2% in mixing efficiency. 5. A reduction of 100 ml in tidal volume in normal subjects was associated with a decrease of 6.9% in alveolar mixing efficiency. In the subjects receiving atropine tidal volume reduced by 96 ml, but the observed fall in alveolar mixing efficiency was only 3.5%, This suggests an improvement in alveolar mixing of 3.4% due to the administration of atropine. Despite this small improvement, the mixing efficiency is still only 66%. The residual inefficiency of 34% cannot therefore be explained on the basis of broncho-motor tone.

Study of pulmonary function tests in tobacco factory workers

2018 ◽  
Vol 6 (3) ◽  
pp. 16-19
Author(s):  
Gajanan V Patil ◽  
◽  
Atish Pagar ◽  
U S Patil ◽  
M K Parekh ◽  
...  
Keyword(s):  
Pulmonary Function ◽  
Pulmonary Function Tests ◽  
Factory Workers ◽  
Function Tests

Pulmonary Function Tests in European Birth Cohorts

2013 ◽  
Vol 9 (1) ◽  
pp. 3-10
Author(s):  
Linus Grabenhenrich ◽  
Cynthia Hohmann ◽  
Remy Slama ◽  
Joachim Heinrich ◽  
Magnus Wickman ◽  
...  
Keyword(s):  
Pulmonary Function ◽  
Pulmonary Function Tests ◽  
Birth Cohorts ◽  
Function Tests

Pulmonary Function Tests Fail to Predict Exercise Intolerance in Sheep with Emphysema

2005 ◽  
Vol 37 (4) ◽  
pp. 550-556
Author(s):  
MELISSA R. MAZAN ◽  
EDWARD P. INGENITO ◽  
LARRY TSAI ◽  
ANDREW HOFFMAN
Keyword(s):  
Pulmonary Function ◽  
Pulmonary Function Tests ◽  
Exercise Intolerance ◽  
Function Tests

ISOLATED ABNORMALITIES OF DIFFUSION CAPACITY (DLCO) IN PULMONARY FUNCTION TESTS AMONG INNER CITY PATIENTS

CHEST Journal ◽  
2008 ◽  
Vol 134 (4) ◽  
pp. 49S
Author(s):  
Ibrahim H. Abou Daya ◽  
Muhammad U. Anwer ◽  
Gilda Diaz-Fuentes ◽  
Steve Blum ◽  
Latha Menon
Keyword(s):  
Pulmonary Function ◽  
Inner City ◽  
Pulmonary Function Tests ◽  
Diffusion Capacity ◽  
Function Tests

Shrinking lung syndrome in pediatric systemic lupus erythematosus

Lupus ◽  
2021 ◽  
pp. 096120332110103
Author(s):  
Alfonso Ragnar Torres Jimenez ◽  
Nayma Ruiz Vela ◽  
Adriana Ivonne Cespedes Cruz ◽  
Alejandra Velazquez Cruz ◽  
Alma Karina Bernardino Gonzalez
Keyword(s):  
Systemic Lupus Erythematosus ◽  
Pleural Effusion ◽  
Pulmonary Function ◽  
Lupus Erythematosus ◽  
Pulmonary Function Tests ◽  
Age At Diagnosis ◽  
X Rays ◽  
Systemic Lupus ◽  
Function Tests ◽  
Restrictive Pattern

Shrinking Lung Syndrome (SLS) is a rare and little known complication associated with Systemic Lupus Erythematosus (SLE), characterized by progressive and unexplainable dyspnea, pleuritic pain, small pulmonary volumes and elevation of the diaphragm on chest X-rays as well as restrictive pattern on pulmonary function tests. Objective To describe clinical, radiological and treatment characteristics in pediatric patients with SLS. Material and methods This is a descriptive and retrospective study in patients under 16 years old with the diagnosis of SLE complicated by SLS at the General Hospital. National Medical Center La Raza. Clinical, radiological and treatment variables were analyzed. Results are shown in frequencies and percentages. Results Data from 11 patients, 9 females and 2 males were collected. Mean age at diagnosis of SLS was 12.2 years. Age at diagnosis of SLE was 11.1 years. SLEDAI 17.3. Renal desease 72%, hematological 91%, lymphopenia 63%, mucocutaneous 72%, neurological 9%, arthritis 54%, serositis 91%, fever 81%, secondary antiphospholipid syndrome, low C3 72%, low C4 81%, positive ANA 91%, positive anti-DNA 91%. Regarding clinical manifestations of SLE: cough 81%, dyspnea 91%, hipoxemia 81%, pleuritic pain 71%, average oxygen saturation 83%. Chest X-rays findings: right hemidiaphragm affection 18%, left 63%, bilateral 18%. Elevated hemidiaphragm 91%, atelectasis 18%, pleural effusion 91%, over one third of the cardiac silhouette under the diphragm 36%, bulging diaphragm 45%, 5th. anterior rib that crosses over the diaphragm 91%. M-mode ultrasound: diaphragmatic hypomotility 100%, pleural effusion 63%. Pulmonary function tests: restrictive pattern in 45% of the cases. Treatment was with supplementary oxygen 100%, intubation 18%, antibiotics 100%, steroids 100%, intravenous immunoglobulin 54%, plasmapheresis 18%, cyclophosphamide 54% and rituximab 18%. The clinical course was favorable in 81%. Conclusions SLS should be suspected in patients with SLE and active disease who present hipoxemia, pleuritic pain, cough, dyspnea, pleural effusion and signs of restriction on chest X-rays. Therefore, a diaphragmatic M-mode ultrasound should be performed in order to establish the diagnosis.

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