Treatment of status asthmaticus in children: is there a place for sodium bicarbonate?

Introduction

Status asthmaticus is frequently associated with metabolic acidosis and acidosis reduces the effectiveness of β-agonists. In January 1999 we initiated a new protocol for the treatment of status asthmaticus in which the use of intravenous sodium bicarbonate was added if the pH is below 7.15 in patients with refractory status asthmaticus. This was based upon previous reports in the literature. It was postulated that refractory status asthmaticus could benefit from treating acidosis, although others have pointed out the risk of hypercapnia.

Objective

To investigate the effect of the administration of sodium bicarbonate on carbon dioxide levels in children with status asthmaticus and to evaluate the clinical effect of this treatment modality in reducing the number of ventilated patients.

Methods

We retrospectively studied the children with status asthmaticus admitted to the pediatric intensive care unit (PICU) that received sodium bicarbonate. The following data were collected from the charts: demographic data (age, sex), weight, severity of asthma, duration of admission, treatment of the status asthmaticus and blood gas before and after the administration of sodium bicarbonate.

Measurements and results

During the 2.5-year period reviewed, 42 patients with status asthmaticus were admitted to the PICU. Sodium bicarbonate was given in six patients with a mean total dose of 1.2 mmol/kg (0.57–4 mmol/kg). One patient received two doses of sodium bicarbonate during the same admission. Five of these patients that received sodium bicarbonate, were not mechanically ventilated. It is very likely that all five patients would have been intubated and mechanically ventilated if there had been no improvement of the respiratory distress after the administration of sodium bicarbonate. In the patient who was already mechanically ventilated, sodium bicarbonate was given after intubation. There was a significant decrease of pCO₂ after sodium bicarbonate infusion (P = 0.009). Also there was a decrease of the respiratory distress. We did not observe adverse effects such as hypokalemia, hypernatremia or aggravation of the altered mental status. Since the initiation of the new protocol four patients were mechanically ventilated, but they were all intubated in the referring hospital prior to admission to the PICU. All patients survived.

Conclusion

Since the initiation of a treatment protocol for status asthmaticus in which sodium bicarbonate was added, sodium bicarbonate was administered in six patients. In these patients there was a significant decrease in pCO₂ and an amelioration of the respiratory distress. No adverse effects were observed. Also since then no patient required intubation after admission to the PICU.