# Tubular Injury: Support Recovery Without Adding Harm

A recovery diuresis can create water and electrolyte deficits. Continue reassessment during improvement and arrange follow-up for persistent kidney risk.

![Infographic: Tubular Injury: Support Recovery Without Adding Harm](https://urinenephrology.org/visual-reference/images/mastery-tubular-injury.png?v=20261003c)

## Injury and dysfunction

Ischemia, toxins, sepsis, and pigment exposure can disrupt tubular transport and filtration. Injury mechanisms frequently overlap in critically ill patients.

## Recognize the pattern

Granular casts and tubular epithelial cells support tubular injury. A bland sediment, variable fractional excretion, or a low BUN:creatinine ratio cannot exclude it.

## Reconstruct the timeline

Examine hypotension, infection, exposures, fluid balance, and drug accumulation. Exclude obstruction and investigate glomerular or interstitial alternatives when clues point elsewhere.

## Link treatment to the current threat

Treat sepsis, obstruction, or the identified toxin and correct demonstrated hypovolemia with reassessment. Refractory hyperkalemia, severe acidemia, pulmonary edema, or uremic complications may require KRT. Continued oliguria after fluids calls for a new volume assessment, not an automatic repeat bolus.

## Use diuretics for congestion

Loop diuretics can manage fluid overload when a response is possible. Increased urine output does not demonstrate reversal of tubular injury or improved kidney recovery.

## Track recovery and losses

A recovery diuresis can create water and electrolyte deficits. Continue reassessment during improvement and arrange follow-up for persistent kidney risk.

## Supporting evidence

- [KDIGO 2012 AKI guideline](https://kdigo.org/wp-content/uploads/2016/10/KDIGO-2012-AKI-Guideline-English.pdf)

## Source lessons

- [atn comprehensive intrinsic extrinsic review](https://urinenephrology.org/mastery/aki-advanced/atn-comprehensive-intrinsic-extrinsic-review.html)
- [atn loop diuretics report](https://urinenephrology.org/mastery/aki-advanced/atn-loop-diuretics-report.html)

Read alongside the full lessons; the findings and decisions shown here require the stated clinical context.