NR 601 Week 1 Note -PFT Interpretation

NR 601 Week 1 Note -PFT Interpretation

NR 601 Week 1 Note -PFT Interpretation

NR 601-Week 1 Note

PFT interpretation:

Step 1

FEV1 normal 80% -120% , FVC 80% -120%, FEV1/FVC ratio >70%

Step 2

Gold 1 (mild) EFV1 > or equal 80% predicted

Gold 2 (Moderate) EFV1 > 50-79% predicted

Gold 3 (severe) EFV1 > 30-49% predicted

Gold 4 (very severe) EFV1 < 30 predicted

Step 3

Reversibility: Reversibility is measured by pre and post bronchodilator spirometry test

Spirometry—short acting bronchodilator- repeat test 10-15 mins after— significant response in adult is considered > or equal to 12% improvement in EFV1 or FVC and an absolute improvement of > or equal 0.2L (This indicate Asthma)

COPD:

Global initiative for COPD (GOLD) criteria: Consider COPD in any patient with the following: Dyspnea, Chronic cough or sputum production, and/or exposure to any of the previous risk factors (Smoking, occupational exposure) non modifiable risk factor such as age >40, alpha 1 antitrypsin deficiency and other childhood severe lung infection, h/o TB, low socio-economic status, and GERD.

Assessment Criteria:

Dyspnea (progressive, worse with exercise, increased effort to breath)

Chronic cough (intermittent or nonproductive)

Chronic sputum production (any pattern)

Histories of exposure to risk factors (smoke, occ. Dust, chemical, fumes, or smoke from cooking or heating fuels)

Exam: decrease breath sound, wheezes at base, cyanosis, leaning forward with arm support, use of accessory muscle, neck vein distension

Diagnosis: Spirometry is the gold standard because it helps to distinguish the stage. Can perform both pre and post bronchodilator. Irreversible airflow limitation I the hallmark of COPD.

Treatment:

Bronchodilators: Beta 2 agonists eg. Albuterol, levalbuterol, salmeterol,(long acting, short acting)

Anticholinergics (long acting tiotropium, short acting ipratropium)

Short acting bronchodilator must be used as a rescue drugs.

Theophylline: oral bronchodilator  which can be used if symptoms continued despite combination inhaled bronchodilator, or if cost of inhaler is high, risk of toxicity in elderly with liver disease and heart failure, narrow therapeutic index (5-12).

Side effects

Beta-2-agonist: tachycardia, palpitation, muscle tremors, cramping, insomnia, hypokalemia, prolong QT, hyperglycemia

Anticholinergics: dry mouth and constipation

Inhaled corticosteroid (ICS) monotherapy is only FDA approved for rx of asthma not COPD. In COPD must be used with long acting bronchodilators.

PFT: Pulmonary function tests provide a quantifiable measurement of lung function and are utilized to diagnose respiratory abnormalities or assess the progression or resolution of lung disease.

ERV: The expiratory reserve volume is the maximum volume of air exhaled from end-expiration and is useful to identify lung or chest wall restriction

RV: The residual volume is the volume of air remaining in the lungs after a maximal exhalation. A low RV indicate restrictive lungs disease.

TV: Tidal volume measures the volume of air inhaled or exhaled during each respiratory cycle.

Functional residual capacity FRC:  is the volume of air in the lungs at resting end expiration

Inspiratory capacity is sum of tidal volume and inspiratory reserve volume.

Total lungs capacity is vital capacity plus residual volume.

Spirometry is most frequently used measure of lungs function.

FVC: total volume of air expelled and is a measurement over time.

FEV1 is forced exhalation volume in the first second of the forced exhale. FEV1 measure how quickly full lungs can be emptied. FEV1 to FVC ratio is the percentage of maximum inspiration expired in one second.

KINDLY ORDER NOW FOR A CUSTOM-WRITTEN, PLAGIARISM-FREE PAPER

1^st step: Determine is the FEV1/FVC ratio is low. Reduction is less than 80% of the predicted value. COPD is diagnosed when the post bronchodilator FEV1/FVC is <70%.

2^nd step: Once you know there is obstruction, look at the FEV1 to assess severity.

FEV1 > or equal to 80% mild obstruction

FEV1 between 50-79% moderate obstruction

FEV1 between 30-49% severe obstruction

FEV1 less than 30% very severe obstruction

Step 3^rd: Determine reversibility – pre and post bronchodilator spirometry is performed to measure obstruction reversibility. Short acting bronchodilator is administering and repeat test in 10-15 mins. Significant response in adult is considered > or equal to 12% improvement in the FEV1 or FVC and an absolute improvement of > or equal 0.2L. Significant response indicate asthma.

Week 3 Note: …