Severe hypernatremic dehydration in an infant causing aortic
A 15-day-old male infant presented to the emergency department with severe dehydration. He was born at term without complications and had been receiving 3 daily feedings.

Physical examination revealed a pulse rate of 80 beats/min, a temperature of 35.5°C (96°F), and absent femoral pulses with poor distal perfusion. Investigations showed a sodium level of 173 mmol/L and platelet level of 60/mm3. Abdominal ultrasonography (Figure 1, Figure 2, Figure 3) was performed to investigate poor perfusion.

The infant was diagnosed with hypernatremic dehydration leading to aortic occlusion. The cause of the patient’s condition was attributed to inadequate feeding. On admission, he began receiving heparin, and the sodium level was slowly corrected. He was discharged uneventfully on day 10, and follow-up ultrasonography showed decreased thrombus burden with improved distal perfusion.

Clinical Pearls:-
- This life-threatening illness can result from an inadequate oral intake, diabetes insipidus, or excess water loss, and can present with acute renal failure, neurologic injury, and thrombosis.

- Treatment consists of correcting the hypernatremia slowly and correcting the total body free-water deficit.

- Chronic hypernatremia should not be corrected by more than a decrease in sodium level of 0.5 mEq/L per hour (10 to 12 mEq/L per day) to prevent cerebral edema. Treatment of the aortic occlusion involves reversing the underlying cause, as well as providing anticoagulation.