Acute Kidney Injury in Neonates and Infants
Increasing serum creatinine (Cr)
Decreasing urine output to less than 0.5–1 mL/kg/h
History and Physical Examination
Table 99-1 provides information on the history and physical examination.
Table 99-1History and Physical Examination Findings in Neonates/Infants With Acute Kidney Injury (AKI) |Favorite Table|Download (.pdf) Table 99-1History and Physical Examination Findings in Neonates/Infants With Acute Kidney Injury (AKI)
|Findings ||Comments |
|Prenatal ultrasound (US) || |
Oligohydraminios/anhydraminios in obstructive uropathy
Renal hypoplasia, dysplasia, and other structural abnormalities
|Perinatal history || |
|Umbilical artery/vein catheterization? || |
|Exposure to nephrotoxic medications? || |
Aminoglycosides, nonsteroidal anti-inflammatory drugs (NSAIDs), other antimicrobials, chemotherapy agents
|Physical Examination |
|Weight trend || |
|Urine output || |
|Hypertension || |
|Hypotension || |
|Heart murmur || |
|Abdominal examination || |
Significant distention may suggest abdominal compartment syndrome or urine ascites causing “pseudo”-AKI (rare).
Tenderness may suggest renal vein thrombosis.
Mass may suggest autosomal recessive polycystic kidney disease (ARPKD)/obstructive AKI.
|Potter syndrome || |
Pulmonary insufficiency, flattened nasal bridge, low-set ears, joint contractures seen in obstructive uropathy
|Gross hematuria || |
Check electrolytes, complete blood cell count (CBC)
Consider urinalysis, urine sodium, urine urea, urine Cr (FeNa, FeUrea)
Consider renal ultrasound (RUS) with Doppler to evaluate structure and blood flow
Consider prerenal, intrinsic, postrenal (obstructive) causes of acute kidney injury (AKI)
Clues to prerenal AKI
Hypovolemia on examination
Negative fluid balance
FeNa less than 2.5% or FeUrea less than 35%
FeNa = (Urine Na × Plasma Na) × 100(Urine Cr × Plasma Cr)
FeUrea = (Urine Urea × Plasma Serum Urea Nitrogen) × 100(Urine Cr × Plasma Cr)
Clues to intrinsic AKI
Prolonged hypovolemia or hypotension
Exposure to nephrotoxic medication
Presence of clinical conditions associated with AKI
(1) Sepsis/multiorgan dysfunction syndrome
(2) Congenital cardiac surgery
(3) Perinatal asphyxia
(4) Extracorporeal membrane oxygenation (ECMO)
Clues to postrenal (obstructive) AKI
Prenatal history of hydronephrosis/other urologic anomaly
RUS showing thickened bladder wall, dilated collecting system, hydronephrosis
Assess fluid status; fluid resuscitate if hypovolemic
Ensure blood pressure is adequate for renal perfusion
Vasopressor support if needed
Consider urethral Foley catheter placement
Relieves possible obstruction.
Facilitates strict in and out measurement.
Measures intravesical pressure via Foley catheter if there is concern for abdominal compartment syndrome. In children and infants, abdominal compartment syndrome has been described in those with intraabdominal pressures greater than 10–12 mm Hg.
Consider acute management therapies for intrinsic AKI