We present the case of a three-month-old infant with a history of refusal of feedings, nausea, regurgitation and vomiting of one month's evolution. For this reason he was referred from Primary Care to the Emergency Department.
He was a full-term newborn of appropriate weight for gestational age, with a normal pregnancy course in which no polyhydramnios was observed. The neonatal period was uneventful, with adequate psychomotor and weight and weight-related development until two months of age, when he began to show the symptoms described above.
On arrival at the emergency department, he appeared to be in poor general condition, with dry mucous membranes, haggard, capillary refill greater than 2 seconds and skin pallor, with the rest of the physical examination being normal. Vital signs were: temperature, 36.6°C; heart rate, 137 bpm; blood pressure, 88/55 mmHg (p75); O2 saturation, 100%; respiratory rate, 52 rpm; blood glucose, 90 mg/dl. Weight 5.995 kg (P10), height 60.5 cm (P10). He was expanded with physiological saline solution and blood tests were performed, with a normal haemogram and biochemistry showing: Na 151 mEq/l; K 2.2 mEq/l; Cl 130 mEq/l and in the venous blood gas analysis: pH 7.29, pCO2 27 mmHg, bicarbonate 13 mmol/l and ionic calcium 1.74 mg/dl. Findings compatible with metabolic acidosis with normal anion gap. A urine dipstick was performed on urine from one urination with pH 7, density 1015 and negative remainder.
The patient required intravenous serum therapy with maximum potassium (80 mEq/l) and bicarbonate (3 mEq/kg/day), and was discharged after a week, maintaining oral treatment with sodium bicarbonate and potassium citrate. Renal ultrasound showed bilateral papillary hyperechogenicity, compatible with the onset of nephrocalcinosis. Ophthalmological assessment, bone series and auditory potentials were normal.
During follow-up until nine months of age, the patient was asymptomatic, with improvement in weight-for-nature development (p25 for weight and p50 for height), and treatment doses were adjusted according to the change in weight. The blood tests six months after discharge are shown in Table 2. In the control ultrasound performed six months after discharge, the findings compatible with nephrocalcinosis persisted.