Renal, Urology and Electrolytesmiddle twist
A 68-year-old man with a recent transurethral resection of a bladder tumour presents with worsening suprapubic pain and inability to pass urine. He has passed bright-red urine with numerous dark clots, and the bladder is palpable and tender. His blood pressure is normal and his haemoglobin is unchanged from yesterday. Which one of the following should be undertaken first?