OVERVIEW
Atresia Pulmonary Syndrome is a progressive exacerbation of airway obstruction to a critical state in patients with bronchial asthma.
Etiology
Repeated nebulized inhalation of isoprenaline can lead to swelling of the bronchial mucosa and narrowing of the lumen, coupled with β-receptor blockade by the intermediate product, 3-methoxyisopropyladrenaline, and further dysfunction of the ventilation/blood flow ratio; obstruction of the main bronchial lumen by bronchial mucus or extensive embedding of mucus plugs in the fine bronchi; and exacerbation of bronchospasm by inappropriate use of the β-blocker propranolol.
Symptoms
Sudden worsening of stridor, telangiectasia, severe cyanosis, slowing to cessation of respiration, and profuse sweating. Physical signs include significant chest expansion, decreased or absent breath sounds in both lungs, and audible dull rales. Heart rate increase is often >150 beats/min, and there may be a drop in blood pressure and cardiac arrhythmias.
Examination
1. Laboratory examination
Blood gas analysis has PaO2 decrease, PaCO2 increase and acid-base disorder, etc. Lung function test lung capacity and FEV1% are significantly reduced, and airway resistance is increased.
2. Other auxiliary examinations
Chest X-ray examination shows that the translucency of both lungs is enhanced, and there is no obvious difference between expiratory and inspiratory phases.
Diagnosis
Diagnosis can be made on the basis of history and clinical manifestations, chest X-ray blood gas analysis and pulmonary function tests.
Differential diagnosis
Clinically, it should be differentiated from respiratory failure.
Complications
Complications include cardiac arrhythmias and electrolyte disorders.
Treatment
1. Treatment of etiology
Discontinue isoproterenol aerosol or propranolol (cardiac glycosides). Repeated suctioning should be done when there is a large amount of secretion mucus plug obstructing the airway, or therapeutic bronchial lavage should be done via fibrinoscopy in order to improve ventilation. Avoid sedatives such as morphine or barbiturates.
2. Treatment of mild cases
Oxygen can be given immediately by high-flow oxygen, or high-frequency jet ventilation; methylprednisolone, dexamethasone and aminophylline can be given. Budesonide suspension can be tried for nebulized inhalation. At the same time to be appropriate amount of rehydration and lysis of enzyme agents, in order to correct dehydration and dissolve the mucus plugs in the bronchial tube should also pay attention to correcting electrolyte disorders. Repeated patting of the back for the conscious person can assist in expectoration to reduce airway obstruction.
3. Treatment of severe or concomitant hypercapnia
Tracheal intubation or tracheotomy should be carried out, mechanical ventilation or artificially assisted respiration, but attention should be paid to slowly reduce the CO2 tension, so as to avoid the complication of alkalosis when correcting respiratory acidosis caused by CO2 retention, and at the same time, it is conducive to sputum suction, oxygenation and intratracheal drug administration.
Prognosis
The prognosis is poor in severe cases or those with more complications.