A NEJATIAN1, B PATEL1, M JOSE1,2
1School of Medicine, University of Tasmania, Launceston, Australia, 2Renal Unit, Royal Hobart Hospital, Launceston, Australia
Aim: To investigate the number, type, and metabolic profile of recurrent kidney stone formers (KSF) referred to a tertiary hospital renal unit.
Background: Up to 15% of adults are affected by kidney stones at some point during their life. For people who have their first stone, up to half will experience a second. Complete metabolic assessment of KSF in the Tasmanian population might allow more effective preventative strategies to be put in place.
Methods: This retrospective clinical audit reviewed adult KSF referred to the Royal Hobart Hospital renal unit between 2009 and 2019.
Results: We only identified 39 adults (18 (46%) women) mean age 52 ± 16.9 years. Overall, 85% of these patients had a previous admission for kidney stones. All patients had pre-existing comorbidities, including hypertension (62%), diabetes (36%) and 46% had a smoking history. Of those with a known BMI, 95% were overweight or obese.
On stone analysis, 21% were calcium oxalate, 13% were staghorn, 8% were urate, 5% were cysteine and the rest (51%) were not recorded. Biochemically, 18% had low serum bicarbonate, 68% had low eGFR, 5% had hypercalcaemia, 14% hyperphosphatemia, 9% had hypophosphatemia, 25% had hyperuricemia and 18% had hypomagnesaemia. Sixteen of 39 (40%) patients had a 24-hour urine assessment where most (56%) had <2L urine volume. Of those tested, 40% had hyperoxaluria (2 of 5), 33% had hypocitraturia (2 of 6) and none had hypercalciuria (0 of 6).
Conclusion: This audit shows stone analysis is underperformed, referral to renal physicians uncommon and there is inconsistent metabolic assessment. A consistent management approach could possibly help improve preventative strategies and reduce future episodes of renal colic or hospital admissions.
Ava Shakila Nejatian is currently undertaking her fourth year of study in the Bachelor of Medicine and Bachelor of Surgery at The University Of Tasmania (UTAS). She previously completed a Bachelor of Medicine Research at UTAS. She is passionate about mentoring junior students, clinical research and the management of patients with chronic disease.