Introduction to

RESPIRATORY MEDICINE

Dr.Bilal Natiq Nuaman,MD. C.A.B.M.,F.I.B.M.S.,D.I.M. 2016-2017 1

BASIC HUMAN SURVIVAL NEEDS:

Oxygen : HUMAN CANNOT SURVIVE

FOR MORE THAN 10 MINUTES WITHOUT OXYGEN

Water : HUMAN CANNOT SURVIVE FOR

MORE THAN 100 HOURS WITHOUT WATER

Food : HUMAN CANNOT SURVIVE FOR MORE THAN 1000 HOURS WITHOUT FOOD

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The primary function of the lungs is gas exchange. This requires the movement of O2 into the blood to support aerobic respiration in the mitochondria and the removal of the metabolic by-product CO2 from the blood.

To achieve this, an integrated system of external respiration (lungs), circulatory system (cardiovascular and hematology systems) and cellular respiration (internal respiration) must function harmoniously.

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Respiratory systemComposed from : 1-Respiratory tracts 2- ventilatory pump 3- Gas exchanger

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1-Respiratory tracts 1-upper respiratory tract : nasopharynx,larynx,p.n.sinuses .

2-lower respiratory tract : trachea, main bronchi ,down to terminal bronchioles.

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2- ventilatory pump consists of the following: 1-Brainstem centers (respiratory centers) that control the

respiratory muscles. 2- The respiratory muscles (internal/external intercostal muscles , diaphragm) , which expand and contract the thoracic cavity.

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3-Gas exchanger Consists of thousands of lung alveoli where O2 and CO2

exchanged through respiratory membrane proportional to the difference in partial pressure.

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MAIN FUNCTIONS OF RESPIRATORY SYSTEM

1-Provides an extensive area for gas exchange between air & circulating blood

2-Assists in the control of acid-base balance

3-Produce sounds involved in speaking.

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Respiratory disease is defined any deviation from or interruption of the normal structure or function of any components of respiratory system (Respiratory tracts, ventilatory pump ,and Gas exchanger),

manifested by a characteristic set of symptoms and signs; and may affect the main functions of respiratory system .

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The Burden of Respiratory Disease

Respiratory disease is responsible for a major burden of morbidity and mortality, with conditions such as tuberculosis, pandemic influenza and pneumonia the most important in world health terms.

The increasing prevalence of allergy, asthma and chronic

obstructive pulmonary disease (COPD) contributes to the overall burden of chronic disease in the community.

By 2025, the number of cigarette smokers worldwide is anticipated to increase to 1.5 billion, ensuring a growing burden of tobacco-related respiratory conditions.

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• 20% of people consulted a physician for a respiratory complaint

• TB infect 1/3 of population

• Respiratory diseases are among the leading causes of death worldwide. Lung infections (mostly pneumonia and tuberculosis), lung cancer and chronic obstructive pulmonary disease (COPD) together accounted for one-sixth of the global total.

• The World Health Organization estimates that the same four diseases accounted for one-tenth of the disability-adjusted life-years (DALYs) lost worldwide in 2008

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• Most of emerging infectious diseases (diseases that appear in the last 30 years) are of respiratory origin like

SWINE FLU (H1N1) , SARS , AVIAN FLU( H5N1), MIDDLE EAST RESPIRATORY SYNDROME

CORONAVIRUS (MERS-COV)

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Diagnosis1-

•HISTORY 2-

• EXAMINATION

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• INVESTIGATIONS 13

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EXAMINATION OF RESPIRATORY SYSTEM

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Pulmonary Function Tests

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➢Basic tests for preliminary assessment and for monitoring disease progression include :-

1-spirometry, which is a record of exhaled volume versus time during a forced exhalation (with or without determination of the response to an inhaled bronchodilator for possible reversible airflow).

• Among the most helpful spirometric values are 1-Forced vital capacity ( FVC ), 2-Forced expiratory volume in the first second of

exhalation (FEV1), and 3-Ratio (FEV1 / FVC).

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NORMAL LEVELS FEV1 > 80% FVC >80 % FEV1/FVC >70%

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2-Diffusion capacity, which measures the transfer of carbon monoxide to indicate how well inspired gases cross the alveolar-interstitial-capillary endothelial interface into blood. diffusion capacity of the lung for carbon monoxide (Dlco)

3-Lung volumes , which include TLC,VC,RV.

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INTERPRETATION OF SPIROMETRY

PULMONARY FUNCTION TESTS HELP TO IDENTIFY AND QUANTIFY ABNORMALITIES OF PULMONARY SYSTEM , WHICH USUALLY ARE CATEGORIZED AS OBSTRUCTIVE OR RESTRICIVE .

❖OBSTRUCTIVE LUNG DISEASE: ➢FEV1 ↓ <80% ➢FVC normal 80% ➢FEV1/ FVC ↓ <70% 22

❖RESTRICTIVE LUNG DISEASE:

FEV1 ↓ <80% FVC ↓ < 80% FEV1/ FVC NORMAL >70%

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Interpretation of transfer factor➢LOW DLCO: Causes

Emphysema , Interstitial lung disease-idiopathic pulmonary

fibrosis Anemia.

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➢HIGH DLCO: Causes

ASTHMA, POLYCYTHEMIA ➢NORMAL DLCO: : CHRONIC BRONCHITIS

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Pulmonary Function Tests

Indications 1. Detect the presence of lung dysfunction classified

as obstructive or restrictive lung disease. 2. Quantify severity of known lung disease 3. evaluation of response to various treatments

including bronchodilators for asthma and corticosteroids for interstitial lung disease

4. monitoring pulmonary side effects of treatment (e.g., methotrexate, amiodarone)

5. Assess the risk for surgery (preoperative assessment)

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Categories of respiratory diseases• 1-obstructive lung disease : partial or complete obstruction of the airways due to

anatomic narrowing or loss of elastic recoil. Causes Asthma, emphysema, chronic bronchitis , bronchiectasis,and cystic fibrosis

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• 2-Restricive lung disease: Reduced expansion of the lung parenchyma due to

restrictive disease of lung,pleura,and chest wall. Causes Interstitial lung disease, Pleural effusion, Pneumothorax, Pleural fibrosis and tumor , Pulmonary embolism, Kyphoscoliosis, Ankylosing spondylitis, Neuromuscular disease,

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• 3-Combination of obstructive and restrictive Due to mixed pathology Causes Lung Infection: TB , Pneumonia. Lung malignancy Sarcoidosis

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Thanks for listening

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