Successful treatment of severe arterial hypotension and anuria in a preterm infant with renal tubular dysgenesis– a case report

Abstract

BackgroundOligohydramnios sequence can be caused by renal tubular dysgenesis (RTD), a rare condition resulting in pulmonary and renal morbidity. Besides typical features of Potter-sequence, the infants present with severe arterial hypotension and anuria as main symptoms. Establishing an adequate arterial blood pressure and sufficient renal perfusion is crucial for the survival of these infants.Case presentationWe describe a male preterm infant of 34 + 0 weeks of gestation. Prenatally oligohydramnios of unknown cause was detected. After uneventful delivery and good adaptation the infant developed respiratory distress due to a spontaneous right-sided pneumothorax and required thoracocentesis and placement of a chest tube; he showed no major respiratory concerns thereafter and needed only minimal ventilatory support. Echocardiography revealed no abnormalities, especially no pulmonary hypertension. However, he suffered from severe arterial hypotension and anuria refractory to catecholamine therapy (dobutamine, epinephrine and noradrenaline). After 36 h of life, vasopressin therapy was initiated resulting in an almost immediate stabilization of arterial blood pressure and subsequent onset of diuresis. Therapy with vasopressin was necessary for three weeks to maintain adequate arterial blood pressure levels and diuresis. Sepsis and adrenal insufficiency were ruled out as inflammation markers, microbiological tests and cortisol level were normal. At two weeks of age, our patient developed electrolyte disturbances which were successfully treated with fludrocortisone. He did not need renal replacement therapy. Genetic analyses revealed a novel compound hyterozygous mutation of RTD. Now 17 months of age, the patient is in clinically stable condition with treatment of fludrocortisone and sodium bicarbonate. He suffers from stage 2 chronic kidney disease; blood pressure, motor and cognitive development are normal.ConclusionsRTD is a rare cause of oligohydramnios sequence. Next to pulmonary hypoplasia, severe arterial hypotension is responsible for poor survival. We present the only second surviving infant with RTD, who did not require renal replacement therapy during the neonatal period. It can be speculated whether the use of vasopressin prevents renal replacement therapy as vasopressin increases urinary output by improving renal blood flow.

A Premature Baby with Severe Oligohydramnios and Hypotension: a Case Report of Renal Tubular Dysgenesis

“…Hypotension is the major challenge during the first days of life in patients with RTD. While vasopressin was reported as helpful to remedy hypotension in survived cases, 14 18 it was not effective in our case. Volume repletion using volume expanders such as fresh frozen plasma, which reversed hypotension in a few cases, 4 14 was not effective either.…”

“…Laboratory findings also supported the diagnosis of genetic RTD in this case; In RTD with RAS mutations, except REN , the renin expression is usually increased as a result of negative feedback on the RAS pathway. 3 4 12 Since ACE was mutated in our patient, serum ACE and aldosterone levels were low, 14 but, serum ANG II was increased above the normal range of age. Considering that serum ANG II increases after birth in preterm babies, 15 it can explain the increase of ANG II in our patient.…”

“…Volume repletion using volume expanders such as fresh frozen plasma, which reversed hypotension in a few cases, 4 14 was not effective either. There are reports that fludrocortisone can be used for electrolyte stabilization and can significantly improve clinical outcomes, 14 18 but in our patient, fludrocortisone was helpful only in electrolyte stabilization.…”

“…Almost all the reported patients, similar to our patient, needed renal replacement therapy, and all the survived cases except one had chronic kidney disease. 12 14 19 20 In Korea, only one case was reported until now, and that patient survived with chronic kidney disease stage 2. 19 …”

“… 4 12 Rather than the specific type of variations or causative gene, response to supportive care for respiratory difficulty and hypotension is more important for the neonatal survival; 10 rapid recovery of diuresis is considered a favorable prognostic factor. 10 14 19 …”