1. PHARMACOTHERAPY - I PHCY 310
University of Nizwa
College of Pharmacy and Nursing
School of Pharmacy
PHARMACOTHERAPY - I
PHCY 310
Lecture 7 Respiratory Disorders “Pulmonary Function Tests” Dr. Sabin Thomas, M. Pharm. Ph. D. Assistant Professor in Pharmacy Practice School of Pharmacy University of Nizwa

2. Anatomy and Physiology of Lungs
Left and right lungs are in the pleural cavity of the thorax.
Right lung has three lobes, but the left has only two lobes; space is thus provided for the heart.
Lungs are connected to pharynx by trachea.
Trachea splits into left and right main stem bronchi that deliver inspired air to respective lungs.

4. Main bronchi split into smaller bronchi, bronchioles, terminal bronchioles and finally alveoli.
In alveoli, the lungs exchange carbon dioxide for oxygen across a thin membrane separating capillary blood from inspired air.
Thoracic cavity is separated from abdominal cavity by diaphragm-a thin sheet of dome shaped muscles-contracts and relax during breathing.

5. Lungs are contained within the rib cage but rest on the diaphragm.
Between the ribs are two sets of intercostal muscles-attach to each upper and lower rib.
During inhalation, the intercostal muscles and diaphragm contracts, thereby enlarging the thoracic cavity.
This generates a negative intrathoracic pressure, allowing air to rush in through nose and mouth down into pharynx, trachea and lungs.
Purpose of lungs is to take oxygen from the atmosphere and exchange it for CO2 in blood.

6. Spirogram

7. Introduction Pulmonary Function Tests (PFTs) are useful
- in diagnosing respiratory disorders.
- to monitor therapy for patients with respiratory diseases.

8. Introduction Clinical uses of PFTs: Evaluate respiratory symptoms
Screen for respiratory diseases
Assess disease severity
Monitor the cause of disease
Evaluate the response to therapy
Assess the risk of pulmonary exposure to environmental toxins

9. 1. Forced expiratory volume (FEV1) using spirometer.
Invistigations:
1. Forced expiratory volume (FEV1) using spirometer.
2. Forced vital capacity (FVC) using spirometer.
3. FEV1/FVC: it should be ≥ 75% for proper lung performance.
4. Peak expiratory flow rate (PEFR) using peak flow meter.
FEV1: the forced expiratory volume in 1st second of
exhalation (after maximum inspiration).
FVC: the forced expiratory volume after maximum inspiration.
spirometer

10. PEFR (self assessment):
This is the speed of the air
moving out of patient’s lungs
at the beginning of the
expiration, measured in liters
per second.

11. Reversibility
A significant reversibility is defined as an improvement of 12% and200 ml in FEV1 15 to 20 minutes post inhaled short acting β2 agonist.
A lack of response to bronchodilator testing in the laboratory does not preclude a clinical response to bronchodilator therapy
(ATS/ERS task force Euro Resp J 2005)
A lack reversibility cannot asses the bronchoprotective property of medication