ESPE2014 Poster Category 2 Bone (1) (12 abstracts)
aDepartment of Endocrinology & Diabetes, Murdoch Childrens Research Institute at The Royal Childrens Hospital, Parkville, Melbourne, Australia; bDepartment of Neonatology, The Royal Childrens Hospital, Parkville, Melbourne, Australia; cDepartment of Endocrinology & Diabetes, Monash Childrens Hospital, Clayton, Melbourne, Australia
Background: The effect of bisphosphonates in patients with severe osteopenia of prematurity is unknown in terms of either fracture prevention or long-term safety. A 6-month-old male infant born at 24+2 weeks gestation was referred for consideration of bisphosphonate therapy in the management of severe osteopenia of prematurity. The neonatal course included chronic lung disease requiring four courses of corticosteroids. Despite optimal calcium, phosphate and vitamin D supplementation an atraumatic oblique femoral fracture was documented at 4 weeks corrected age. The infant remained mechanically ventilated after two failed attempts at extubation, despite minimal ventilator requirements. One further attempt at extubation was planned with palliation thereafter if unsuccessful.
Objective and hypothesis: It was postulated that severe osteopenia of the ribs was contributing to inadequate chest wall movement and support. Given the end of life nature of the request, a decision was taken to trial bisphosphonates to improve chest wall function after counselling that this was in the absence of any published evidence of benefit in this scenario.
Methods: A single dose of zoledronic acid 0.02 mg/kg (0.07 mg) was given which was well tolerated.
Results: Successful extubation to CPAP occurred 1 week later; serum alkaline phosphatase had decreased from 2190 to 1094 IU/l (normal range 100350) during this timeframe. At 8 months corrected, no further fractures have occurred and the infant remains on nasal oxygen at home.
Conclusion: In this instance, the use of zoledronic acid was used to confer mechanical support to the chest wall of a ventilator-dependent infant with complex medical needs. Successful extubation was temporally related to the administration of a single dose of the bisphosphonate. Potential mechanisms include pain reduction or strengthening of the thoracic cage. Clinical trials are warranted prior to general consideration of change in management practice, but in extreme circumstances this stratagem may be considered.