How Long Should We Monitor the Patient for Bleeding after Percutaneous Renal Biopsy?

Purpose: Percutaneous renal biopsy (PRB) may become complicated by serious bleeding. Overnight observation after renal biopsy is a standard safety strategy. Although it was recently reported that outpatient observation is safe, appropriate observation time after the renal biopsy is still in debate. We evaluated prospectively the incidence, onset time and risk factors of hemorrhagic complications to determine the optimal duration of observation after PRB. Methods: We enrolled 100 patients who underwent renal biopsy from October 2009 to April 2010 using the standard strategy. The biopsy was performed by two experienced nephrologists using 16-gauge spring-loaded biopsy gun under real-time ultrasound guidance. Serial color Doppler ultrasound was done immediately, 8 hours, 24 hours and 1 week after the PRB. Results: The 32 patients experienced hemorrhagic complications (32.0%, 10 with gross hematuria, 26 with hematoma, and 4 with both), and 1 major complication occurred 3 days after PRB. Baseline serum creatinine of the patient with the major complication was 6.0 mg/dL. Serum creatinine and BMI were higher in complication group (p<0.05). Number of needle passes, blood pressure, and degree of edema and proteinuria were not related to the complication. In multivariate analysis, serum creatinine was the only significant risk factor of complication (p=0.007). Hemorrhagic complications developed in 9 patients (28.1%) between 8 and 24 hours after PRB, all of which were minor. Conclusion: The 8 hours observation time after renal biopsy may be deemed appropriate for stable patients with normal creatinine.Y