Neonatal Med.  2018 Aug;25(3):131-135. 10.5385/nm.2018.25.3.131.

A Rare Case of Hyponatremia Caused by Reset Osmostat in a Neonate with Cleft Lip, Cleft Palate, and Imperforate Anus

• Ahn JG
• Lee JE
• Chung WY
• Koo SH
• Shin J
• Jeon GW

• KMID: 2436130
• DOI: http://doi.org/10.5385/nm.2018.25.3.131

Abstract

Hyponatremia is defined as a plasma sodium concentration of < 135 mEq/L. It is a common electrolyte imbalance in newborns. We report the case of a term neonate with cleft lip, cleft palate, imperforate anus, normal male karyotype, and chronic hyponatremia. On the 4th day of life, he showed hyponatremia (plasma sodium concentration 130 mEq/L) with low serum osmolality (275 mOsm/kg), high urine sodium (116.7 mEq/L), and high urine osmolality (412 mOsm/kg). His thyroid and adrenal functions were normal. Despite intravenous and oral sodium supplementation and hydrocortisone treatment, hyponatremia persisted. Brain magnetic resonance imaging showed normal results. He was diagnosed as having reset osmostat, a rare subtype of the syndrome of inappropriate secretion of antidiuretic hormone characterized by a subnormal threshold for antidiuretic hormone secretion, with hypotonic hyponatremia.

Keyword

Hyponatremia; Inappropriate ADH syndrome; Newborn; Cleft palate; Imperforate anus

MeSH Terms

Anus, Imperforate*
Brain
Cleft Lip*
Cleft Palate*
Humans
Hydrocortisone
Hyponatremia*
Inappropriate ADH Syndrome
Infant, Newborn*
Karyotype
Magnetic Resonance Imaging
Male
Osmolar Concentration
Plasma
Sodium
Thyroid Gland
Hydrocortisone
Sodium

Figure

• 

  Figure 1. Photographs of the face. (A) Hypertelorism, maxillary hypoplasia, low nasal bridge, and cleft lip and palate. (B, C) Short anteroposterior diameter with a flat occiput.

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  Figure 2. Photographs of the anus. Imperforate anus with lowtype anocutaneous fistula.

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