Salbutamol-Induced QT Interval Prolongation in a Two-Year-Old Patient

Abstract

Salbutamol-induced QT interval prolongation is a relatively rare adverse effect of beta2-agonists. We report a case of a two-year-old female patient with no known past medical history, brought by her parents to the ED 30 minutes after ingesting a total dose of 97 mg of salbutamol solution. ECG was done for the patient when she arrived and showed sinus tachycardia with prolonged QTc (509 ms) and normal QRS complex. The patient was admitted to the Pediatric Intensive Care Unit (PICU) with persistent tachycardia and tachypnea in the initial reassessment. ECG was repeated with normal QT interval after IV Mg sulfate. The patient was observed in PICU for 12 hours with serial ECG and venous blood gas (VBG). IV potassium chloride (KCL) infusion started, and serial VBG showed normal potassium and lactate. The patient was doing well in the next six hours, with normal serial ECG, labs, and vital signs. In conclusion, salbutamol-induced QT prolongation has infrequently been reported in the literature. Although inhaled salbutamol is commonly used in clinical practice, physicians have limited experience with the severe features of its toxicity. Salbutamol is known to cause minimal side effects, which may be under-recognized and progress to serious manifestations such as hypokalemia, QT prolongation, and sudden cardiac death.

Diagnosis, complication and treatment of acute salbutamol toxicity

“…The syndrome of beta 2-agonist toxicity should be known to all doctors because it might result in QT prolongation and sudden cardiac death. 7 It is not recommended to administer systemic salbutamol via intravenous infusion to asthma patients beyond the clinical studies due to its metabolic effects, which could exacerbate respiratory function in asthma. Consideration should be made to other therapy such non-invasive ventilation for patients who don't respond to systemic steroids, ipratropium, or inhaled beta 2-agonists rather than increasing the dosage potency or amount of a medication that could paradoxically make respiratory function worse.…”