Management of Post-Obstructive Acute Kidney Injury
Diagnosis and Assessment
- The American College of Gastroenterology recommends that AKI is diagnosed when serum creatinine increases by ≥0.3 mg/dL within 48 hours, increases ≥50% from baseline, or when urine output is reduced below 0.5 mL/kg/h for >6 hours 2
- Post-obstructive AKI should be identified through a careful history, physical examination, blood biochemistry, urine studies, and renal ultrasound 2
- Post-obstructive causes are relatively rare but important to identify as they are often readily reversible 1
Supportive Care After Relief of Obstruction
- The American Journal of Kidney Diseases recommends holding diuretics and discontinuing nephrotoxic medications (especially NSAIDs) 2, 1
- The American Journal of Kidney Diseases suggests assessing volume status and providing appropriate fluid management, using isotonic crystalloids rather than colloids for volume expansion 3, 4
- The National Kidney Foundation recommends adjusting medication dosages according to current renal function 1, 5
Prevention of Secondary Kidney Injury
- The National Kidney Foundation advises avoiding nephrotoxic medications including NSAIDs, aminoglycosides, and contrast agents 1, 5
- The National Kidney Foundation recommends being cautious with ACE inhibitors, decongestants, antivirals, and herbal products 5
- The National Kidney Foundation suggests avoiding pharmacodynamic drug interactions such as the "triple whammy" of NSAIDs, diuretics, and ACE inhibitors/ARBs 6
- The American College of Gastroenterology recommends monitoring for and aggressively treating infections, as they can worsen kidney injury 2
Monitoring and Follow-up
- The American College of Gastroenterology recommends monitoring urine output, vital signs, and when indicated, using echocardiography or CVP to assess fluid status 2
- The National Kidney Foundation suggests regular assessment of kidney function with serum creatinine measurements 7
- The American Journal of Kidney Diseases recommends evaluating patients 3 months after AKI for resolution, new onset, or worsening of pre-existing CKD 8