Value of Immediate Post-Kidney Biopsy Ultrasound in Excluding Late Hemorrhagic Complications

Hemorrhage is the most serious potential complication of percutaneous kidney biopsy. Patients are typically observed for at least 6-8 hours after a kidney biopsy, with serial measurements of vital signs and hemoglobin to monitor for major hemorrhage. This study assessed whether an immediate postbiopsy ultrasound can reliably exclude delayed major hemorrhage.

We retrospectively evaluated the clinical outcomes in 147 patients undergoing an outpatient native kidney biopsy with an 18-gauge needle at a large medical center during a 2.5-year period (January 2017 to June 2019). All patients underwent a standardized postbiopsy ultrasound to assess for active extravasation of blood. We extracted from the medical records vital signs and hemoglobin values obtained before the biopsy and at 2, 4, and 6 hours after the procedure. We ascertained whether any patients with a negative postbiopsy ultrasound developed a delayed major hemorrhage.

Each patient underwent two or three biopsy passes. The mean patient age was 48±17 years, 49% were female, 37% were black, 53% had hypertension, and 16% had diabetes. Of the 142 patients without evidence of active extravasation on ultrasound, the BP, heart rate, and hemoglobin remained stable during 6 hours of observation. All were discharged after 6 hours, and none had a late bleeding complication.

If the immediate postkidney biopsy ultrasound does not show active bleeding, the patient is extremely unlikely to develop a late major hemorrhagic complication (negative predictive value, 100%). Such patients can be discharged home safely after a 2-hour observation, thereby simplifying their management.