• Bladder distension;
  • creatinine;
  • hydronephrosis;
  • oliguria;
  • ultrasound

Aim: To describe the association between morphine administration in preterm infants, hydronephrosis, and renal dysfunction. Methods: The findings were based on serial ultrasound examinations and blood studies. Results: Two preterm infants had bladder distension and hydronephrosis after they received intravenous morphine for analgesia. Morphine was used at a low dose. Each patient had a normal urine output and normal serum creatinine before the signs and symptoms of urinary retention were observed. Within 24 h of morphine administration, each infant concurrently developed oliguria and elevation of the serum creatinine. Cessation of morphine and urinary drainage resulted in rapid and complete resolution of the hydronephrosis and the elevated creatinine.

Conclusion: Morphine, even at low dosages, can be associated with hydronephrosis in hospitalized preterm infants.