SP732MANAGEMENT OF CHRONIC HYPOTENSION WITH MIDODRINE HYDROCHLORIDE IN ANURIC PAEDIATRIC DIALYSIS PATIENTS

Abstract

Introduction and Aims: Chronic hypotension and intra-dialytic hypotension in anuric children with fluid overload is a frustrating problem that prevents achievement of euvolaemia with dialysis. Consequently these children are at risk from acute haemodynamic instability, ischaemia, cardiac arrhythmia and cardiac arrest related to severe hypotension during dialysis. In addition chronic fluid overload has a deleterious effect on the cardiovascular system. Midodrine is an oral alpha 1-agonist with antihypotensive/vasopressor properties. In an effort to improve treatment tolerance and fluid removal, we commenced midodrine therapy in 9 children who failed to tolerate dialysis ultrafiltration despite interventions such as sodium modelling, increased frequency of dialysis and blood volume monitoring. Method(s): 9 dialysis dependent children between age 8 months to 17 years with significant fluid overload and systolic blood pressure repeatedly at or below 5th percentile for age received midodrine therapy. Midodrine was administered one hour prior to haemodialysis and again mid dialysis on dialysis days. Short synacthen studies performed in four of the children were normal. Blood pressure, heart rate and oxygen saturation were recorded every 30minutes during dialysis. Result(s): A review of patient data showed an increase in systolic BP 10-30mm Hg and better tolerance of dialysis in most children. Two adolescent patients with significant hypotension, dizziness and lethargy on non-dialysis days required additional midodrine 5mg-10mg off dialysis to control their symptoms. One infant on peritoneal dialysis commenced midodrine had no improvement in blood pressure, suggestive of impaired cardiac function. There have been no serious adverse events associated with midodrine in our patients. Conclusion(s): Midodrine provided some improvement in chronic hypotension and intra-dialytic symptoms in 8 of the 9 patients. Midodrine is removed by haemodialysis, therefore dosing prior to dialysis and mid dialysis is recommended.