Objective Postnatal dexamethasone therapy is controversial. This study aimed to determine the short-term effects of Minidex (low-dose dexamethasone 0.05 mg/kg/day) on ventilator-dependent preterm babies.

Methods Very preterm babies (less than 30 weeks of gestation or under 1500 g) who were ventilator dependent at over 2 weeks of life and received Minidex therapy (low-dose dexamethasone 0.05 mg/kg/day for 10 days followed by alternate-day doses for 6 days) were compared retrospectively to a matched comparison group who received neither Minidex nor standard-dose dexamethasone.

Results 50 babies who received Minidex were compared to a comparison group of 26 babies. Babies treated with Minidex extubated significantly faster than controls, Cox regression hazard ratio 6.24 (95% CI 2.34 to 16.63). By day 4, 34% of babies treated with Minidex had extubated but no controls had. Babies who received Minidex showed significant improvements in both ventilatory index and oxygen requirements, had no increased rate of clinical hypertension (OR 1.16 (95% CI 0.42 to 3.21)) or hyperglycaemia (OR 1.55 (95% CI 0.44 to 5.45)) and had a similar rate of chronic lung disease at 36 weeks' corrected age (OR 1.61 (95% CI 0.62 to 4.22)). No baby developed gastrointestinal perforation or haemorrhage.

Conclusion Minidex therapy facilitates extubation and is not associated with clinically significant short-term side effects. A randomised controlled trial is required to further assess efficacy and long-term outcomes.