Is there a need to treat hypokalaemia associated with intravenous salbutamol infusion?

OBJECTIVES

To investigate the evolution of metabolic effects associated with intravenous salbutamol infusion given together with 2 doses of intramuscular steroids in the treatment of preterm labour.

METHODS

Preterm labour was inhibited with an intravenous infusion of salbutamol in 8 women between 26 and 32(+6) weeks with normal singleton pregnancies. Serum glucose concentration, serum potassium, sodium and insulin concentrations, and total white cell count both during the infusion as well as post-therapy, were plotted against time.

RESULTS

Intravenous salbutamol infusion administered at a rate required to inhibit uterine contractions in preterm labour causes a rise in serum glucose and plasma insulin concentrations. The serum glucose and plasma insulin levels peaked soon after cessation of therapy and took 2-3 hours to come to pre-infusion levels. The decline in serum potassium concentration was gradual and plateaued after 2 hours. Once the salbutamol infusion was stopped the potassium levels were back to normal by 2 hours. There is an increase in total white cell count within an hour of the initiation of therapy.

CONCLUSION

There is no need to administer insulin for hyperglycaemia and/or potassium for hypokalaemia unless the patient is a known diabetic or when a patient needs immediate surgery.