Masking of syndrome of inappropriate antidiuretic hormone secretion: the isonatremic syndrome

Syndrome of Inappropriate Antidiuresis

The syndrome of inappropriate antidiuresis (SIAD) is a common cause of hyponatremia in hospitalized children. SIAD refers to euvolemic hyponatremia due to nonphysiologic stimuli for arginine vasopressin production in the absence of renal or endocrine dysfunction. SIAD can be broadly classified as a result of tumors, pulmonary or central nervous system disorders, medications, or other causes such as infection, inflammation, and the postoperative state. The presence of hypouricemia with an elevated fractional excretion of urate can aid in the diagnosis. Treatment options include fluid restriction, intravenous saline solutions, oral sodium supplements, loop diuretics, oral urea, and vasopressin receptor antagonists (vaptans).

Full Volume Isotonic (0.9%) vs. Two-Thirds Volume Hypotonic (0.18%) Intravenous Maintenance Fluids in Preventing Hyponatremia in Children Admitted to Pediatric Intensive Care Unit-A Randomized Controlled Study

BACKGROUND

We aimed to compare the effect of two different intravenous fluid regimes on the incidence of hyponatremia in children.

METHODS

Children 1 month to 18 years of age, admitted to pediatric intensive care unit (PICU) of a tertiary care medical college hospital were randomized to receive either isotonic fluid (0.9% saline in 5% dextrose) at the standard maintenance rate or hypotonic fluid (0.18% saline in 5% dextrose) at two-thirds of the standard maintenance rate.

RESULTS

A total of 240 children were randomized (120 isotonic, 120 hypotonic). In all, 16.7% children in hypotonic group developed hyponatremia compared with 7.5% in isotonic group (p = 0.029). Duration of PICU stay was significantly more in Hypotonic group.

CONCLUSION

We conclude that use of 0.9% saline in 5% dextrose as maintenance fluid helps in reducing the incidence of hospital-acquired hyponatremia and duration of intensive care unit stay among children admitted to PICU.

Early Intranasal Vasopressin Administration Impairs Partner Preference in Adult Male Prairie Voles (Microtus ochrogaster)

Research supports a modulatory role for arginine vasopressin (AVP) in the expression of socially motivated behaviors in mammals. The acute effects of AVP administration are demonstrably pro-social across species, providing the justification for an ever-increasing measure of clinical interest over the last decade. Combining these results with non-invasive intranasal delivery results in an attractive system for offering intranasal AVP (IN-AVP) as a therapeutic for the social impairments of children with autism spectrum disorder. But, very little is known about the long-term effects of IN-AVP during early development. In this experiment, we explored whether a single week of early juvenile administration of IN-AVP (low = 0.05 IU/kg, medium = 0.5 IU/kg, high = 5.0 IU/kg) could impact behavior across life in prairie voles. We found increases in fecal boli production during open field and novel object recognition testing for the medium dose in both males and females. Medium-dose females also had significantly more play bouts than control when exposed to novel conspecifics during the juvenile period. Following sexual maturity, the medium and high doses of IN-AVP blocked partner preference formation in males, while no such impairment was found for any of the experimental groups in females. Finally, the high-dose selectively increased adult male aggression with novel conspecifics, but only after extended cohabitation with a mate. Our findings confirm that a single week of early IN-AVP treatment can have organizational effects on behavior across life in prairie voles. Specifically, the impairments in pair-bonding behavior experienced by male prairie voles should raise caution when the prosocial effects of acute IN-AVP demonstrated in other studies are extrapolated to long-term treatment.