Acute kidney injury (AKI) is characterized by an abrupt decline in kidney function, with subsequent reduced elimination of waste products, causing electrolyte and fluid imbalances. To avoid serious irreversible consequences, AKI requires prompt diagnosis and treatment [1][2].
In most current guidelines, AKI is measured by increased creatinine levels relative to baseline and/or decreased urine output volume over set time periods. It’s important to emphasize that the serum creatinine level (sCr) does not reflect the glomerular filtration rate (GFR) and will not rise until approximately 50% of kidney function is lost. Essentially, by the time the sCr level rises significantly, kidney damage may have already occurred. Moreover, some cases of AKI do not show an increase in SCR levels. Finally, in nearly one in five critically ill children, no increase in sCr was detected, yet AKI was identified by urine output criteria [3]. Thus, urine output data is the most accessible, reliable, and affordable biomarker.
The etiology of AKI can be multifactorial, including reduced blood flow to the kidneys, direct damage to the kidneys themselves, or obstruction of the urinary tract [1][2]. Hospital-acquired AKI is a common complication in surgical wards, with an incidence rate of approximately 5-7% [4]. In intensive care units (ICUs), the incidence of AKI is even higher, ranging from 30-50% [4]. These high complication rates highlight the significance of HAAKI and emphasize the need for early detection and intervention, as AKI is associated with significant morbidity and mortality. Increased risk for developing HAAKI is also multifactorial, including nephrotoxic-drug-induced sepsis, hypotension, and volume depletion, or a combination of these causes [5].
Monitoring urine output is crucial in detecting early signs of kidney function deterioration. A decline in urine output may be the only initial sign of AKI, making it a valuable indicator for healthcare professionals to identify and promptly manage the condition [4]. By carefully measuring urine output, healthcare providers can assess kidney function and make timely adjustments to treatment plans. When AKI is detected, expeditious intervention is crucial to prevent further kidney damage and improve patient outcomes.
The recommendations for treatment adjustment may include [6]:
- Treating the underlying cause of AKI, such as dehydration or infection.
- Adjusting medication doses to avoid further kidney damage.
- Monitoring fluid intake and output to ensure appropriate fluid balance.
- Providing renal replacement therapy such as dialysis, if necessary, to remove waste products from the blood.
References:
1 http://www.ncbi.nlm.nih.gov/books/NBK441896/
2 http://www.kidney.org/atoz/content/AcuteKidneyInjury
3 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3919808/
4 http://www.nature.com/articles/s41572-021-00284-z
