RS

        The aspirin hypersensitivity phenomenon is relatively uncommon in children with asthma, but more prevalent in adults. Estimates that it affects between 10% and 25% of adult asthmatics with so-called “triad asthma”: asthma plus nasal polyps and chronic urticaria.

·         The term asthma derives from a Greek word that means, literally, “to pant.”

·         The earliest signs and symptoms of excess of theophylline involve CNS stimulation (jitteriness, tremors, difficulty sleeping, anxiety). As blood levels rise the CNS is increasingly stimulated. Seizures may occur, and when they do the inability to breathe during the seizures is the main cause of death. Theophylline tends to cause tachycardia, increases of cardiac contractility and, potentially, tachyarrhythmias. Bradycardia is not at all likely. Theophylline is not hepatotoxic, it does not cause paradoxical bronchospasm, even when serum levels are very high or truly toxic.

·         When pulmonary function deteriorates so much that respiratory acidosis ensues (because sufficient amounts of CO2 aren’t being eliminated by ventilation) and severe hypoxia develops (because of inadequate oxygen transfer), acute tolerance (in essence, desensitization) develops to the bronchodilator effects of drugs with β2- agonist activity—all of them. If this point is forgotten, repeated administration of a β2 agonist will lead to increasing degrees of cardiac stimulation (rate, contractility, automaticity, conduction) because under these conditions they lose their selectivity for β2 receptors and also begin activating β1 receptors very effectively. (They become isoproterenol-like in their profiles.)

Even epinephrine won’t work as an efficacious bronchodilator under these conditions, and repeated injections of it will do little more than cause further cardiac stimulation plus vasoconstriction via α activation. Through mechanisms that are not quite clear, administering suitable doses of a parenteral steroid under these conditions of acidosis and hypoxia “restores” a substantial degree of airway responsiveness to β agonists. Giving a steroid (plus oxygen, which helps correct the underlying blood gas and pH changes) is essential.

Giving diphenhydramine, even though it blocks the bronchoconstrictor effects of both ACh and histamine, will not do much good for the acute and life-threatening signs and symptoms. Giving cromolyn will prove largely worthless and certainly not life-saving.

ONLY IV HYDROCORTISONE WORKS.