Abstract
Hypernatremic dehydration is a lethal condition in neonate which adversely affects central nervous system. Important causes of this condition in neonate are vomiting, diarrhea, improper preparation of infant formula, inadequate breast feeding and diabetes insipidus. Hypernatremic dehydration presents usually around tenth postnatal day. Clinical presentation is variable. Some present with lethargy; others are alert and hungry. Some are dehydrated whereas other are apparently hydrated. Treatment of hypernatremic dehydration consists of an emergency phase where restoration of vascular volume with 10 to 20 ml/kg of isotonic intravenous fluid is achieved followed by rehydration phase where sum of free water deficit and maintenance fluid volume is administered slowly. Rehydration is achieved with 5% dextrose in 0.2% normal saline, 5% dextrose in 0.45% normal saline or 0.9% normal saline according to serum sodium level. However, if the serum sodium is greater than 175 mmol/L, various amounts of 3% normal saline should be added. The daily maximum correction rate of serum sodium level should be 15 mmol/L. Addressing the etiological factors timely may be the proper way of prevention of such condition in neonate.

Key words: Hypernatremia, dehydration, newborn, management.