Hyperkalemia after endobiliary radiofrequency ablation for malignant biliary obstruction.

Inoue, Tadahisa; Kitano, Rena; Yoneda, Masashi

A 77-year-old-man with pancreatic head cancer and chronic kidney disease developed obstructive jaundice. Endoscopic transpapillary drainage failed because of tumor invasion to the duodenum, and endoscopic ultrasound-guided drainage was attempted. After penetrating the left intrahepatic duct via the stomach, a guidewire was passed through the lower bile duct stricture. The fistula was dilated using a 4-mm dilatation balloon catheter, and a Habib EndoHPB Catheter (Boston Scientific, Marlborough, Massachusetts, USA) was inserted. Subsequently, the stricture was ablated at a power of 7W for 90 seconds.1 A metallic stent was deployed antegrade across the stricture, and a single-pigtail plastic stent was deployed across the fistula (Fig. 1). The patient's vital signs were stable during the procedure. However, severe bradycardia occurred 2 hours later with the heart rate plummeting below 20-30 bpm and electrocardiogram showing flattened P-waves and prolonged QRS complex. A blood test revealed serum potassium levels of 7.4 mEq/L, which had been 4.6 mEq/L at pre-procedure. Calcium was administered immediately, and glucose-insulin therapy was initiated. One hour later, serum potassium levels decreased to 5.8 mEq/L and stabilized at 4.8 mEq/L 12 hour later. The patient's symptoms gradually improved.