Asthma is a long term disease of the AIRWAYS which carry the air to the lungs. These  airways becoe so narrow that it becomes difficult to breathe properly giving rise to acute attacks like breathlesness and wheezing. The air is unable to move in and out of the tubes freely.

THE RESPIRATORY TRACT 

CAUSES OF BRONCHIAL  ASTHMA

Certain factors trigger the asthmatic condition. These are listed below.

1. Smoking

2. Pollen grains 

3. Occupational : Asbestosis, Interstitial Lung Disease

4. Allergy to dust, smoke,automobile exhausts or animal dander

5. Infections of the bronchi, sinuses, tonsils or adenoids.

6. Emotional  factors

7. Environmental changes in temperature and humidity

8. exposure to noxious fumes.

9. Strenous physical activity.

10. Antihypertensive drugs like BETA BLOCKERS.

11. Immune activation

Allergic or Atopic asthma is also called EXTRINSIC asthma which may be precipitated due to Immunological reactions. 

Infective asthma is also known as INTRINSIC asthma caused by infection of the respiratory tract.

WHAT HAPPENS IN BRONCHIAL ASTHMA ?

The different triggering mechanisms mentioned above may stimulate the MAST CELLS present in our body which in turn causes secretion of the mucous which clogs the airways. The  inflammation of the airways leads to its narrowing. The condition may become so severe that ultimately the patient struggles to breathe in and out leading to wheezing. 

THE STRUCTURE OF A NORMAL AND A CONSTRICTED AIRWAY

SYMPTOMS

1.Breathlessness

2. Wheezing and whistling in the chest

3. Classical sitting position : leaning fowards

4. Dusky and pale lips 

5. Blue nails

6. Dry cough

7. Thick tenacious mucoid sputum

8. Perspiration may be present 

9.Tightness in the chest.

STATUS ASTHMATICUS

This is a condition when the acute attacks of Asthma becomes so severe that it does not respond to standard treatments. It is life threatening and considered a medical emergency. The symptoms are as follows.

1. Breathlessness turns to gasping and difficulty in talking and going to sleep at night.

2. The rate of breathing may be increased to more than 25 breaths /min

3. The heart rate may be increased to more than 110 breaths/min

4. Oxygen saturation levels may be less than 92%

5. On listening through the stethoscope, there may be diminished air entry to the lungs

[ A SILENT CHEST MUST BE VERY DANGEROUS]

6. There might be widespread wheeze

7. There might be abnormal lowering of blood pressure

8. Patient may even go to **HEART FAILURE.**

9. Patient may become drowsy due to HYPOXIA (reduced oxygen to the brain and vital organs).

DIAGNOSIS

1. CLINICAL SYMPTOMS   

2. PHYSICAL  EXAMINATION : cyanosis, pigeon chest,clubbing of the nail bed,prominent neck veins and neck muscles.

3. SPIROMETRY : This measure the amount of air one can breathe in and out and also measures the degree of constriction and obstruction.

INCENTIVE SPIROMETRY

4. BEDSIDE BREATHING TESTS : Breath holding tests, candle blowing tests, Peak flowmeter. 

A PEAK FLOWMETER

5. ALLERGY TESTING :People may be allergic to animal fur, stool and urine of the cats. They may be also allergic to pollen dust, specific food items or cosmetic items.

6. PULMONARY FUNCTION TESTS : This measures the degree of obstruction in the airways or the degree of restriction of the movement of the chest

7. CHEST X-RAY : This may show the condition of the lung fields, the ratio between the heart and the chest wall and the also the airways.

8. CT SCAN of Thorax

9. ARTERIAL BLOOD GAS analysis.

PREVENTION & TREATMENT

1. Avoidance of the triggering factors and the allergens.

2. Rest and relaxation

3. Deep breathing exercises

4. Incentive spirometry

5. Bronchodiators which increase the size of the lumen of the airways and prevent secretions.

# Salbutamol

# Epinephrine

# Steroids

# Aminophylline

# Expectorants

6. Drink large quantities of water to replace the fluid deficit due to swelling & inflammation of the airways

7. Nebulization,inhalers & spacehalers

woman using an INHALER.

8. Mast cell stabilizing drugs & Leukotreine modifiers as a PROPHYLACTIC TREATMENT

9. Those who are taking BETA BLOCKERS as antihypertensive medicines must slowly taper off and stop the drug and replace them with another as er your physician's prescription.

10. Anti reflux medicines can be given to control the reflux leading to Asthma in kids.

TREATMENT OF STATUS ASTHMATICUS

1. CALL FOR HELP IMMEDIATELY FOR HOSPITALIZATION.

2. Intravenous drugs like Magnesium sulphate, Aminophylline, Epnephrine, Beta agonists & Steroids.

3. Aerosolised medication with 100% oxygen & corticosteroids.

4. Intravenous Normal Saline for hydration.

5. Correct the status of elevtrolytes

6. Oxygen Therapy : ( If patients are not ventilated ) : Rebreathing masks,nasal canula,or Bipap masks.

7. Ventilate the patient : Positive pressure therapy with mechanical ventillation.

8. Antibioics to control the infection.

9. Modification of diet to control the allergens.

10.. Chest Physiotherapy.

11. In case of a PNEUMOTHORAX , a chest tube drainage is done.

12. ECMO : Extra Corporeal Membrane Oxygenation.

MONITORING & INVESTIGATIONS IN INTENSIVE CARE UNIT

1. Pulse Oximetry to measure the oxygen saturation.

PULSE OXIMETER

2. Arterial Blood Gases to monitor the amount of carbon dioxide in blood.

3. CT Scan of Thorax

4. Chest X-Ray

5. Pulmonary Function tests : cannot be done on mechanically ventilated patients

6. ECG

7. 2 D ECHO CARDIOGRAPHY to rule out heart failure