Pseudohypoaldosteronism Type 1: A Rare Cause of Severe Dyselectrolytemia and Cardiovascular Collapse in Neonates
A 7 day old male child was brought to emergency department with poor feeding for 72 h and progressive lethargy for 24 h. He was the second child of non-consanguineous parents and had a birth weight of 2.7 kg. There was no family history of sudden infant deaths or children on hormone replacement. At admission, he was pale and lethargic with poor capillary refill suggestive of shock. His weight was 2.1 Kg (weight loss of 22%). There was mild icterus. The heart rate was 160/min; respiratory rate was 60/min; and mean arterial pressure was 56 mm Hg. He was resuscitated with fluid boluses and phototherapy had begun. Meanwhile, wide QRS tachycardia was noticeable in the ECG tracings. Complete blood count, sepsis work up, blood culture, serum electrolytes, and serum bilirubin were sent. The serum level of potassium was reported to be very high (8.96 mEq/L). There was hyponatremia, acidosis, and hyperbilirubinemia. The test results are summarized in .\nBaby was immediately started on measures to reduce serum potassium like intravenous calcium, sodium bicarbonate, and insulin dextrose infusion. While arrangements were being made for dialysis, he developed ventricular arrhythmia and had cardiac arrest. He was revived with cardiopulmonary resuscitation and emergency peritoneal dialysis was instituted, after which the potassium level began to decline.\nWe thought of adrenal insufficiency in view of hyperkalemia, hyponatremia and acidosis. Appropriate hormonal studies were sent, and the results of which are presented in . The level of 17-OHP was normal, whereas serum aldosterone and plasma renin activity were raised, thereby excluding CAH. He had high urine spot sodium and low spot potassium. Urine culture was sterile and ultrasound abdomen excluded obstructive renal tract anomaly.\nAs the clinical course and investigations were suggestive of PHA type 1, hydrocortisone was stopped. Initially, the baby required parenteral rehydration, but subsequently oral rehydration with common salt (30 mEq/kg/day) added to breast milk was sufficient. Potassium level was kept under check with the use of potassium binding resin (kayexalate) in a dosage of about 2 to 3 g/kg/day, (dosage adjusted according to potassium level). Baby was discharged after his blood sodium and potassium levels were stable for 96 h without intravenous fluids, and there was consistent weight gain.\nDuring the initial follow period, baby developed recurrent skin infections with staphylococcus aureus which were treated with oral antibiotics. Baby had mildly elevated calcium: creatinine ratio (0.8), hence hydrochlorthiazide was added in the hope that it will protect against nephrocalcinosis as well as reduce the requirement of kayexalate. During the next 5 months, his requirement of salt supplementation decreased considerably. At 6 months of age, he was on 2 gram/day of common salt (6 mEq/kg/day), apart from the sodium present in kayexalate (10 mEq/kg/day). He weighs 5.8 kg and the development mile stones were appropriate for this age. He required one more hospital admission at 3 months of age for dehydration accompanying a respiratory illness during which he needed intravenous rehydration.