INHERITED LUNG DISEASES
CYSTIC FIBROSIS :-
The most common lethal inherited disease of whitish that defined as a disease of
the exocrine gland that cause viscid secretion .the GIT , and pulmonary system are
most commonly and most severely affected .
Pathogenesis :-
Cystic fibrosis is inherited as autosomal recessive gene that located on
chromosome no. 7 .The defect in cystic fibrosis is thought to be blocked or closed
chloride channel in the cell membrane of epithelial cells . this blockage traps
chloride ions inside the cell and draws ions and water into the cell . this process
results in dehydration of the mucous secretion .
Clinical features :-
1 . respiratory insufficiency , occurs eventually in more than 95 % of all patients and
caused by abnormal mucous gland secretion in the airway producing airway
obstruction and secondary infection , cough , dyspnea , bronchiectasis ,
pneumothorax and finely corpulmonale is a late complication .
2.GIT , chronic diarrhea and malabsorption .
3- reproductive defect including sterile male and reduce fertility in females .
4.hepatic manifestation , that ends with portal hypertension .
5.pancreatic with diabetic mellitus .
6.skeletal abnormalities with arthritis and joint pain .
7.nasal including chronic sinusitis with nasal polyps .
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Diagnostic criteria of cystic fibrosis :-
• 1 . positive sweat test by skin test > 6 MEq /L .
• 2 . typical pulmonary manifestation .
• 3 . typical GIT manifestation ( meconium ileus , chronic diarrhea , rectal prolapse ,
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billiary cirrhosis ) .
• 4 . positive family history .
Therapy :-
1 . treatment of pulmonary problems .
2 . chest physiotherapy ( postural drainage , active cycle of breathing ) .
3 . antibiotics given orally , I.v or aerosol especially for staph. And pseudomonas
infection ( aminoglycosides , cephalosporin can be used ) .
4 . bronchodilators and steroid .
5 . pancreatic enzymes replacement .
6 . vitamins supplement , high calorie and protein diet .
7 . treatment of complication accordingly .
8 . lung transplant .
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DISEASES OF PLEURA
PLEURAL EFFUSION :--
Accumulation of fluid in the pleural space whenever the local hydrostatic forces
pushing fluid out of the vascular space exceed osmotic forces pulling fluid back into
the vascular space .
Etiology :-
• 1 . congestive heart failure .
• 2 . hypoprotienemia .
• 3 . obstruction of lymphatic drainage .
• 4 . malignancy .
• 5 . collagen vascular disease .
• 6 . infection of pleura is due to strepto cocus pneumonaie , H . influenza or T .B .
Clinical features :-
In general clinical features of primary disease is the presenting symptoms , but the
patient may complain from pain , dyspnea , and sings of respiratory insufficiency
resulting from compression of the underling lung tissues .
Physical finding include :-
Dullness to percussion , decrease breath sounds , mediastinal shift and decrease
tactile fremitus .
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Diagnosis :-
Is confirmed by chest x-ray . postero- anterior shows uniform opacity with
acurved upper border , when air is also present the fluid line is horizontal .
decubitus views may be helpful to distinguish fluid collection from other densities
in the thorax . diagnostic thoracocetesis may be necessary to establish the cause of
the effusion and to exclude infection .
Most patients with effusion should undergo diagnostic thoracocentesis unless the:-
1 . underling causes for the effusion are clearly evident .
2 . the patient does not have significant respiratory distress .
3 . infection not suspected .
Comparison between transudates and exudates pleural effusion :
Transudate
exudates
1 . low specific gravity < 1.015 high specific gravity
2 . low protein ( < 2.5 g/ dl high protein > 3g / dl
3 . decrease lactic dehydrogenase
increase lactic deh.
4 . low cell count high cell count
5 . high PH low PH
6 . normal glucose low glucose
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Treatment : -
Treatment directed to the underlying condition that cause the effusion and
at relief of mechanical consequences of the fluid collection .
• Small effusion especially if they are trnsudate usually require no treatment
• Large effusion may require drainage with chest tube especially if the fluid is
purulent ( empyema ) .
If the underlying condition is treated successfully the prognosis for patient
with pleural effusion including empyema is excellent
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PNEUMOTHORAX:-
Is the accumulation of air in the pleural space that may result from external
trauma or from leakage of air from the lung or air way ,it may occur spontaneously
Predisposing condition include :-
• 1 . mechanical ventilation .
• 2 . asthma .
• 3 . disorder of collagen .
• 4 . cystic fibrosis .
• 5 . infection especially staph. Pneumonia , T.B.
• 6 . Iatrogenic ( tracheostomy , thorachocentesis ) .
Symptoms of pneumothorax :-
Chest pain , dyspnea , and cyanosis . If the air leak accumulate with mediastinum ,
subcutaneous emphysema may become apparent .
Physical finding :-
Decreased breath sounds , tympanic percussion note , sings of mediastinal shift
and subcutaneous crepitance . Few or no physical sings of pneumothorax may be
present if the amount of air collection is small , but symptoms may progress rapidly
if the air in the pleural space is under pressure ( tension pneumothorax ) with
death resulting if the tension not relieved
DIAGNOSIS :-
The radiography usually confirms the diagnosis ,although in the infant there may be
difficulty in distinguishing pneumothorax from a large diaphragmatic hernia or
giant emphysematous bulla , drink of gastrografin usually resolve the difficulty .
TREATMENT OF PNEUMOTHORAX :-
The treatment depend on the amount of air collected and the nature of the
underling cause ,
• Small pneumothorax often do not need treatment and resolve spontaneously .
• Large pneumothrax and tension peumothorax require immediate drainage of air .
• In emergency situation a simple needle aspiration may sufficient , but placement of
chest tube may be require for resolution .
• Sclerosing the pleural surfaces to obliterate the pleural space may benefit patient
with recurrent pneumothoraces .
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