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Inappropriate antidiuretic hormone in children with viral meningitis
J E Fajardo1, E M Stafford, J W Bass
1Department of Pediatrics, Tripler Army Medical Center, Honolulu, HI 96859-5000.
Insights
Children with bacterial and viral meningitis often show inappropriate antidiuretic hormone (ADH) secretion, even with normal sodium levels. Most viral meningitis patients, especially infants, may be protected from hyponatremia due to impaired urine concentration.
Area of Science:
- Pediatrics
- Endocrinology
- Infectious Diseases
Background:
- Antidiuretic hormone (ADH) plays a crucial role in fluid balance.
- Infections like meningitis can disrupt normal physiological processes.
- Hyponatremia is a potential complication in pediatric infections.
Purpose of the Study:
- To investigate urinary antidiuretic hormone (ADH) excretion rates in children with bacterial and viral meningitis.
- To compare ADH levels with serum sodium concentrations and urine osmolality.
- To determine if ADH secretion is inappropriate in these pediatric conditions.
Main Methods:
- Radioimmunoassay was used to measure urinary ADH excretion rates.
- Study included children with bacterial meningitis (6), viral meningitis (11), and other febrile illnesses (7).
- Plasma sodium, urine osmolality, and creatinine were measured.
Main Results:
- Elevated urinary ADH excretion rates were observed in most children with bacterial (100%) and viral meningitis (64%), and in 57% with other febrile illnesses.
- Inappropriate ADH secretion (high ADH with normal/low serum sodium) was noted in bacterial and viral meningitis groups.
- Most viral meningitis patients, particularly infants, did not concentrate urine despite high ADH levels.
Conclusions:
- Viral meningitis, similar to bacterial meningitis, is frequently associated with inappropriate antidiuretic hormone secretion.
- Young infants with viral meningitis may be protected from hyponatremia due to an impaired ability to concentrate urine.
- Understanding ADH regulation is critical in managing pediatric meningitis and febrile illnesses.
Abstract:
Urinary excretion rates of antidiuretic hormone were determined by radioimmunoassay in children with bacterial (6) and viral (11) meningitis, and in children with other febrile illnesses (7). These values were compared to normal data obtained from 50 healthy, normally hydrated children ranging in age from 1 week to 9 years. Plasma sodium concentrations were measured in the sick children; urine osmolality and creatinine concentrations were measured in all children. Upon admission, all children with bacterial meningitis and 64% of those with viral meningitis had urinary antidiuretic hormone excretion rates greater than 2 S.D. above values obtained from age-matched controls. Fifty-seven percent of children with other febrile illnesses had similarly elevated antidiuretic hormone values; however, only in the bacterial and viral meningitis groups were antidiuretic hormone excretion rates inappropriate because they occurred when serum sodium concentrations were found to be normal or low normal (i.e., 136 +/- 2 mEq/L and 137 +/- 1 mEq/L, respectively). The average serum sodium in the group with other febrile illnesses was higher (146 +/- 5 mEq/L; p less than 0.05) and could represent an appropriate stimulus for antidiuretic hormone release. In spite of high levels of antidiuretic hormone, most viral meningitis patients did not concentrate their urine, probably because all except 2 were younger than 2 months of age. We conclude that viral meningitis, like bacterial meningitis, frequently is associated with inappropriate antidiuretic hormone secretion; however, most children with viral meningitis may be protected from developing hyponatremia because of their inability to concentrate their urine.