Title : Epoprostenol infusion in pulmonary hypertension: A case of mechanical complication and management
Abstract:
Introduction: Pulmonary hypertension is a chronic progressive disease characterized by raised pulmonary vascular resistance ultimately leading to right sided heart failure. Amongst the current available options for treatment, Epoprostenol has been widely proven to improve symptoms, increase exercise capacity and reduce mortality in idiopathic pulmonary arterial hypertension. However, its short half-life (3 minutes according to BNF), and hence the need for continuous infusion has been a challenging and ongoing concern. The incidence rate for mechanical complications of epoprostenol infusion via hickman line was reported at 0.23 per patient/year in one study (1). In our case report, we discuss a case of pulmonary hypertension on continuous epoprostenol infusion who presented to the emergency departement in a district general hospital on a weekend with infusion interruption secondary to line blockage and how it was managed according to the current available data.
Case summary: This is a 59-year-old gentleman with background of systemic sclerosis, Raynaud’s disease and pulmonary hypertension. He has been on continuous epoprostenol infusion through a hickman line with a portable infusion pump for 10 years along with long term oxygen therapy; 2 litres.He presented to our emergency department when he got alarmed by his infusion pump of an intermittent downstream occlusion every 2-3 minutes. A trial with a different infusion pump was not effective. His observations were stable at this stage with no increased oxygen requirement, and he remained clinically asymptomatic. Given the short half-life of the epoprostenol, he was at increased risk of rebound severe pulmonary hypertension, right ventricular failure, reduced cardiac output and subsequent shock. The patient was then moved to the resuscitation room, he was connected to continuous blood pressure and pulse oximetry monitoring, and his oxygen flow was increased to 5 litres to reduce the risk of pulmonary vasoconstriction.
Two large wide bore cannulas were inserted and the epoprostenol infusion was removed from the hickman line and connected to the pre-flushed wide bore cannula. Clear instructions were distributed through the team to help mitigate the above mentioned risks including; avoid flushing the hickman line to avoid over-dosing, do not flush the cannula’s smart-meter with the epoprostenol infusion to avoid over-dosing, do not give any solutions or medications through the same line with the epoprostenol infusion, avoid interruptions to the epoprostenol infusion, finally safety netting for symptoms of overdosing and underdosing were distributed including, pallor, flushing, drop in systolic blood pressure, jaw pain, diarrhea or collapse for over-dosing and cyanosis, lethargy, increased work of breathing for under-dosing. The patient’s primary pulmonary hypertension was contacted to arrange for safe transfer for continued observation till the hickman was repaired or replaced.
Discussion: Whilst the incidence of mechanical complications in continuous infusion through a hickman line can appear relatively small, the short half-life of epoprostenol and the patient’s dependence on it poses a life-threatening risk of rebound pulmonary hypertension and severe right sided heart failure. Therefore, direct communication with a specialized unit is mandatory when the patient presents to a non-specialized centre. Extensive patient counselling and understanding around the treatment remains a cornerstone in epoprostenol therapy.
