Standardised nurse-led protocol of radiolucent renal and proximal ureteric stones using sodium bicarbonate oral dissolution therapy

Abstract

Objective: Oral dissolution therapy is a recognised treatment option for radiolucent kidney stones. A standardised nurse-led protocol was developed. Efficacy and compliance was audited and results reviewed. Methods: Twenty-two patients with radiolucent stones were prescribed oral sodium bicarbonate. Patients monitored their urinary pH and the Urology Nurse Practitioner checked compliance. Follow-up with non-contrast computerised tomography of the kidneys, ureters and bladder (CT KUB) was evaluated at 6 weeks. Results: Twenty patients with radiolucent stones completed treatment. Mean stone size was 8 mm (2–23 mm). Nine patients (45%) had complete dissolution, three (15%) had partial dissolution and eight (40%) had no visible response on follow-up CT KUB. The Hounsfield unit (HU) average was 464 (116–1285). Those patients with complete dissolution had HU of less than 605. Three patients with encrusted ureteric stents underwent complete dissolution. Conclusions: Utilisation of a nurse-led sodium bicarbonate dissolution therapy protocol for the treatment of radiolucent stones is effective and acceptable to patients in carefully selected cases. Orally dissolution therapy (ODT) is a suitable option in patients with multiple co-morbidities and high anaesthetic risk. In our series, ODT was also highly effective in treating radiolucent stent encrustation.