Background: The efficacy of corticosteroids in reducing the incidence of postextubation laryngeal oedema is controversial. We aimed to test our hypothesis that methylprednisolone started 12 h before a planned extubation could prevent postextubation laryngeal oedema.

Methods: We did a placebo-controlled, double-blind multicentre trial in 761 adults in intensive-care units. Patients who were ventilated for more than 36 h and underwent a planned extubation received intravenous 20 mg methylprednisolone (n=380) or placebo (381) 12 h before extubation and every 4 h until tube removal. The primary endpoint was occurrence of laryngeal oedema within 24 h of extubation. Laryngeal oedema was clinically diagnosed and deemed serious if tracheal reintubation was needed. Analyses were done on a per protocol and intention-to-treat basis. This trial is registered at ClinicalTrials.gov, number NCT00199576.

Findings: 63 patients could not be assessed, mainly because of self-extubation (n=16) or cancelled extubation (44) between randomisation and planned extubation. 698 patients were analysed (343 in placebo group, 355 in methylprednisolone group). Methylprednisolone significantly reduced the incidence of postextubation laryngeal oedema (11 of 355, 3%vs 76 of 343, 22%, p<0.0001), the global incidence of reintubations (13 of 355, 4%vs 26 of 343, 8%, p=0.02), and the proportion of reintubations secondary to laryngeal oedema (one of 13, 8 %vs 14 of 26, 54%, p=0.005). One patient in each group died after extubation, and atelectasia occurred in one patient given methylprednisolone.

Interpretation: Methylprednisolone started 12 h before a planned extubation substantially reduced the incidence of postextubation laryngeal oedema and reintubation. Such pretreatment should be considered in adult patients before a planned extubation that follows a tracheal intubation of more than 36 h.