68: No Urine Output in 24 Hours

I. PROBLEM

Urine output has been scant or absent for 24 hours. One hundred percent of healthy premature, full-term, and post-term infants void by 24 hours of age. Oliguria is defined as urine output <1.0 mL/kg/h for 24 hours. Anuria is defined as absence of urine output usually by 48 hours of age. Oliguria is one of the clinical hallmarks of renal failure. Decreased urine output can be from mild dehydration or acute renal failure (ARF) or acute kidney injury (AKI). ARF/AKI is an acute renal dysfunction and occurs when there is a decrease in glomerular filtration rate, an increase in creatinine and nitrogenous waste products with the loss of ability to regulate fluid and electrolytes. Incidence of neonatal ARF/AKI is around 6–24%. There is a high percentage of ARF/AKI in very low birthweight infants, infants postcongenital heart surgery, infants on extracorporeal membrane oxygenation/extracorporeal life support (ECMO/ECLS) (especially with a congenital diaphragmatic hernia), and infants with perinatal depression.

II. IMMEDIATE QUESTIONS

1. Is the bladder palpable? If a distended bladder is present, it is usually palpable. A palpable bladder suggests there is urine in the bladder. Credé maneuver (manual compression of the bladder) may initiate voiding, especially in infants receiving medications causing muscle paralysis.

2. Has bladder catheterization been performed? Catheterization determines whether urine is presentin the bladder. It is commonly done in more mature infants.

3. What is the blood pressure? Hypotension can cause decreased renal perfusion and urine output. Hypertension may indicate renal/renovascular disease (if severe, suspect renal artery or venous thrombosis).

4. Has the infant ever voided? Did the infant void and was it not recorded on the bedside chart? If the infant has never voided, consider bilateral renal agenesis, renovascular accident, or obstruction. Table 68–1 shows the time after birth at which the first voiding occurs. Remember: voiding can be missed (occurred in the delivery room or with the parents and was not recorded). Approximately 13–21% of infants void in the delivery room.

5. Did the mother have oligohydramnios? One of the etiologies of oligohydramnios (decrease in amniotic fluid) can be caused by a decrease in fetal urine production. This can be caused by renal problems such as decreased renal perfusion, obstructive uropathy, and congenital absence of renal tissue (renal agenesis, cystic dysplasia, and ureteral atresia).

6. Is there gross hematuria? Gross hematuria suggests intrinsic renal disease.

7. What medications was the mother on during her pregnancy? Certain medications (eg, angiotensin-converting enzyme [ACE] inhibitors, nonsteroidal anti-inflammatory drugs [NSAIDS]), if given to the mother during her pregnancy, may interfere with fetal nephrogenesis which can result in fetal renal injury and lead to acute kidney injury in the newborn. ACE inhibitors during pregnancy can cause renal tubular dysgenesis in the infant.

8. Does the infant have a congenital renal disease? Did the prenatal ultrasound suggest kidney disease? Acute renal failure in the newborn may have a prenatal onset. Renal agenesis, renal dysplasia, polycystic kidney disease, and congenital nephrotic syndrome, ...