Complex case of COVID-19 and infective endocarditis.

A 50-year-old man with no medical history of note presented with new onset of confusion and dyspnoea. He tested positive for coronavirus (COVID-19), and subsequently, was admitted to the intensive care unit due to severe sepsis and acute renal failure requiring haemodialysis. Shortly afterwards, he was intubated due to haemodynamic instability. His blood culture was positive for Staphylococcus aureus bacteraemia, and echocardiogram showed evidence of vegetation in the aortic valve area. He was commenced on intravenous antibiotics for infective endocarditis (IE). Following extubation, he underwent an MRI of the spine due to increasing back pain. This was suggestive of L5-S1 discitis, likely secondary to septic emboli from IE. A few days later, he developed acute ischaemia of the left toes and extensive thrombosis of the right cubital and left iliac veins. Following a prolonged hospital admission, he was discharged home and later underwent an elective forefoot amputation from which he made a good recovery.

COVID-19 complicated by immune thrombocytopaenic purpura and internal jugular vein thrombosis.

A 61-year-old woman who had tested positive for COVID-19 in the community 5 days prior to admission presented with new onset severe headache and mild shortness of breath. She had an acute reduction in her platelet counts from 153×109/L to 5×109/L. She was diagnosed with immune thrombocytopenia purpura and after treatment with intravenous immunoglobulin, her platelet count increased to 15×109/L. Due to nonresolving headache, she had a magnetic resonance venogram, which showed bilateral internal jugular vein thrombosis. She was discharged from hospital and followed up in Haematology and Neurology clinics. Her platelet count returned to normal range 7 days later. She was commenced on anticoagulation for thrombosis.

Postsplenectomy thrombocytosis with pseudohyperkalaemia.

A 52-year old man developed hyperkalaemia on the 11th postoperative day following an extensive open retroperitoneal liposarcoma resection that included splenectomy. Despite thorough investigations, no aetiology for the hyperkalaemia was identified and standard empirical treatment was ineffective. On reconsideration, in view of the patient's concurrent thrombocytosis, a pseudofactual or artefactual hyperkalaemia was suspected. This was confirmed by contemporaneous testing of serum and plasma potassium levels, with the latter value lying within the normal range. Treatment for hyperkalaemia was discontinued, thus averting an iatrogenic and potentially dangerous hypokalaemia. This case highlights pseudohyperkalaemia as an often-neglected cause of elevated serum potassium levels and discusses its association with thrombocytosis following splenectomy.