Background: Methylprednisolone remains a commonly used ancillary therapy for paediatric acute respiratory distress syndrome (PARDS), despite a lack of level 1 evidence to justify its use. When planning prospective trials it is useful to define response to therapy and to identify if there is differential response in certain patients, i.e. existence of 'responders' and 'non responders' to therapy. This retrospective, observational study carried out in 2 tertiary referral paediatric intensive care units aims to characterize the change in Oxygen Saturation Index, following the administration of low dose methylprednisolone in a cohort of patients with PARDS, to identify what proportion of children treated demonstrated response, whether any particular characteristics predict response to therapy, and to determine if a positive response to corticosteroids is associated with reduced Paediatric Intensive Care Unit mortality.
Methods: All patients who received prolonged, low dose, IV methylprednisolone for the specific indication of PARDS over a 5-year period (2011-2016) who met the PALICC criteria for PARDS at the time of commencement of steroid were included (n = 78).OSI was calculated four times per day from admission until discharge from PICU (or death). Patients with ≥20% improvement in their mean daily OSI within 72 hours of commencement of methylprednisolone were classified as 'responders'. Primary outcome measure was survival to PICU discharge.
Results: Mean OSI of the cohort increased until the day of steroid commencement then improved thereafter. 59% of patients demonstrated a response to steroids. Baseline characteristics were similar between responders and non-responders. Survival to PICU discharge was significantly higher in 'responders' (74% vs 41% OR 4.14(1.57-10.87) p = 0.004). On multivariable analysis using likely confounders, response to steroid was an independent predictor of survival to PICU discharge (p = 0.002). Non-responders died earlier after steroid administration than responders (p = 0.003).
Conclusions: An improvement in OSI was observed in 60% of patients following initiation of low dose methylprednisolone therapy in this cohort of patients with PARDS. Baseline characteristics fail to demonstrate a difference between responders and non-responders. A 20% improvement in OSI after commencement of methylprednisolone was independently predictive of survival, Prospective trials are needed to establish if there is a benefit from this therapy.