Posterior Urethral Valves (PUV)

Renal function drives the plan - Check serum creatinine, urea, and electrolytes, and make sure they were drawn after the first 48 hours of life; before that the neonate's biochemistry mirrors the mother's, not the baby's. Dose renally cleared drugs to measured function.

Correct potassium and acidosis first - Sick neonates often arrive hyperkalemic and need that corrected before anything else. A blood gas tells you whether a metabolic acidosis is sitting on top of it. Skip succinylcholine while the potassium is up.

Pulmonary hypoplasia - Severe antenatal obstruction with oligohydramnios leaves small, stiff lungs. Expect respiratory distress, high inflating pressures, and a neonate who may already be on ventilatory support.

Urosepsis at presentation - These babies show up with delayed voiding, a weak stream, a palpable bladder, frank urosepsis, or just lethargy and poor feeding. If they are septic, resuscitate and start antibiotics before the scope goes in.

Bladder drainage before ablation - Acute retention is drained with a soft feeding tube rather than a balloon catheter, because the balloon provokes bladder spasm.

Watch for post-obstructive diuresis - Relieving the obstruction can set off prolonged polyuria with heavy salt and water loss, leading to dehydration, electrolyte derangement, hypotension, and hypovolemic shock. Monitor urine output at least every 2 hours and recheck sodium, potassium, urea, creatinine, magnesium, and phosphate. Replace with normal saline capped near 75% of the prior hour's output rather than matching it volume for volume, which just perpetuates the diuresis.

The procedure itself - Cystoscopic valve ablation is the usual first operation, short but not benign; urethral stricture from instrumentation is a recognized complication. In extremely preterm infants the scope often will not fit and a cutaneous vesicostomy is done instead.

They come back - A third have persistent vesicoureteric reflux after ablation, and many need repeat anesthetics for VCUG, urodynamics, ureteric reimplantation, and later transplant surgery. Pull the prior anesthetic records for airway and vascular access notes.

Posterior urethral valves (PUV) are obstructing membranous folds in the lumen of the posterior urethra, found only in males, at roughly 1 in 5,000 to 8,000 births. The obstruction drives bladder wall and detrusor hypertrophy, which lowers compliance and raises intravesical pressure. That pressure transmits up the ureters and produces vesicoureteric reflux, hydroureteronephrosis, recurrent infection, and progressive renal impairment.

When the obstruction is severe in utero, fetal urine output falls, amniotic fluid falls with it, and the lungs never fully develop, so the neonate arrives with pulmonary hypoplasia and respiratory distress. Most survivors carry chronic kidney disease forward, and about half reach end-stage renal disease within ten years. The patient in front of you is usually a neonate with impaired kidneys, possibly hyperkalemic, acidotic, or septic, coming for cystoscopic valve ablation or a vesicostomy.