Native kidney biopsies in older adults: disease spectrum, long-term kidney and patient survival and safety.

PURPOSE: Patients undergoing kidney biopsy are increasingly older. We aimed to evaluate the clinical utility of kidney biopsy, long-term clinical outcomes, and safety of high-risk biopsies in older adults undergoing kidney biopsy in a multi-ethnic Southeast Asian cohort. METHODS: We performed a single-center retrospective study of older patients (age ≥ 60 years) who underwent native kidney biopsies between June 2011 and March 2015. The primary long-term outcome of interest was a composite of ESKD or death. The safety outcome of interest was post-biopsy bleeding in the high-risk subgroup, defined by serum creatinine > 150 µmol/l. RESULTS: Older adults accounted for 153 of 545 (28.1%) native renal biopsies performed. The median age of these older adults was 66.6 (IQR 63.0, 70.6) years. Kidney dysfunction was frequent and severe in this cohort, with 41.2% having eGFR < 30 ml/min/m2 and 71.2% having nephrotic-range proteinuria at presentation. A significant proportion (124 patients; 81.0%) had treatable diagnoses. Of these, 90 (72.6%) received immunosuppressive therapy. On Kaplan-Meier analysis, patients with pauci-immune glomerulonephritis (p = 0.004) and diabetic nephropathy (p = 0.005) were at a significantly increased risk of the composite outcome of ESKD or death. On multivariate analysis, older age and lower eGFR were independently associated with ESKD or death and ESKD alone. Lupus nephritis and diabetic nephropathy were independently associated with ESKD or death, while immunosuppressant therapy was associated with reduced ESKD alone. In the high-risk subgroup, post-biopsy bleeding occurred in 19 (22.8%) patients. Desmopressin use was not associated with reduced bleeding complications. CONCLUSION: Our study confirmed the utility of kidney biopsy in older adult patients for diagnosis and management, although risk counselling and close monitoring for bleeding complications is necessary.

Bleeding Complications and Adverse Events After Desmopressin Acetate for Percutaneous Renal Transplant Biopsy.

INTRODUCTION: Percutaneous renal biopsy remains critical for the workup of renal allograft dysfunction but is associated with the risk of bleeding. Prophylactic intravenous desmopressin has been proposed to reduce bleeding risk in native renal biopsies, but its efficacy in the renal transplant population is unclear and adverse events such as severe hyponatraemia have been reported. MATERIALS AND METHODS: We conducted a single-centre retrospective cohort study involving adult (≥21 years old) renal transplant recipients with impaired renal function (serum creatinine ≥150 µmol/L) who underwent ultrasound-guided renal allograft biopsies from 2011‒2015 to investigate the effect of prebiopsy desmopressin on the risk of bleeding and adverse events. RESULTS: Desmopressin was administered to 98 of 195 cases who had lower renal function, lower haemoglobin and more diuretic use. Postbiopsy bleeding was not significantly different between the 2 groups (adjusted odds ratio [OR] 0.79, 95% confidence interval [CI] 0.26‒2.43, P = 0.68) but desmopressin increased the risk of postbiopsy hyponatraemia (sodium [Na] <135 mmol/L) (adjusted OR 2.24, 95% CI 1.10‒4.59, P = 0.03). Seven cases of severe hyponatraemia (Na <125 mmol/L) developed in the desmopressin group, while none did in the non-desmopressin group. Amongst those who received desmopressin, risk of hyponatraemia was lower (OR 0.26, 95% CI 0.09‒0.72, P = 0.01) if fluid intake was <1 L on the day of biopsy. CONCLUSION: Prophylactic desmopressin for renal allograft biopsy may be associated with significant hyponatraemia but its effect on bleeding risk is unclear. Fluid restriction (where feasible) should be recommended when desmopressin is used during renal allograft biopsy. A randomised controlled trial is needed to clarify these outcomes.

Desmopressin for the prevention of bleeding in percutaneous kidney biopsy: efficacy and hyponatremia.

BACKGROUND: Desmopressin is used to reduce bleeding complications for kidney biopsies with azotemia but little is known about desmopressin-induced hyponatremia in these individuals. We aimed to evaluate the impact of desmopressin prophylaxis on severe hyponatremia and bleeding after kidney biopsies in individuals with renal impairment. METHOD: This is a single-center retrospective cohort study of consecutive adults with serum creatinine ≥ 150 µmol/L and had ultrasound-guided percutaneous native or transplant kidney biopsies between June 2011 and July 2015. Data were retrieved from electronic medical records. Primary outcomes were the use of desmopressin prophylaxis and severe hyponatremia (serum sodium ≤ 125 mmol/L) within 7 days post-biopsy. Secondary outcome was post-biopsy bleeding. RESULTS: 240 native kidney and 196 allograft biopsies were performed. Median age was 51 (IQR 42.3, 60) years and eGFR was 21.9 (12.9, 30.1) ml/min/1.73 m2. Although patients prescribed desmopressin prophylaxis (n = 226) had higher serum creatinine [279 (201, 392) vs. 187 (160, 241), p < 0.001], bleeding (15.0% vs. 13.3%, p = 0.60) was not significantly different with and without desmopressin. Severe hyponatremia occurred in 30 biopsies (6.9%) with nadir serum sodium level of 122 (119, 124) mmol/L at 3 (2, 5) days after biopsy, more frequently among those with desmopressin prophylaxis (10.7% vs. 3.0%, p = 0.002). Multi-variate analysis found that pre-biopsy serum sodium level [adjusted OR 0.80 (95% CI 0.72, 0.90), p < 0.001] and desmopressin prophylaxis [adjusted OR 4.02 (95% CI 1.58, 10.21), p = 0.003] were independently associated with severe hyponatremia after kidney biopsy. CONCLUSION: Pre-biopsy desmopressin was associated with severe hyponatremia in individuals with renal impairment; hence, susceptible patients given desmopressin should be closely monitored.