title: Urinary arginine vasopressin excretion and hyponatremia in the sick neonates.
abstract: We attempted to clarify the renal physiologic response to arginine vasopressin (AVP) in the 12 sick neonates: three with respiratory distress syndrome (RDS), three with meconium aspiration syndrome, two with transient tachypnea of the newborn, two with neonatal asphyxia, and two low birthweight infants during the first 2 days of life. Plasma atrial natriuretic factor (ANF), urinary AVP, osmolality, free water clearance and creatinine clearance (Ccr) were measured at 8 to 16 hours of life (stage 1) and 24 to 32 hours of life (stage 2). Urinary AVP was expressed as the ratio of AVP to Ccr (urine AVP/Ccr). These subjects were divided into two groups: group A represented five infants with a urine AVP/Ccr ratio of 2000 or higher and group B, seven infants with a ratio of less than 2000 at stage 1. Hyponatremia occurred in two infants of group A at stage 2. Number of infants on mechanical ventilation was four in group A and one in group B. There were no significant differences in gestational age, birthweight, Apgar scores at 1 and 5 minutes, blood gas pH and mean arterial blood pressure between groups A and B. A good correlation was observed between logarithm of urine AVP/Ccr ratio and urinary osmolality (p < 0.01). A negative correlation was observed between logarithm of urine AVP/Ccr ratio and free water clearance (p < 0.01). Body weight of infants of group A at stage 2 was greater than at stage 1 (p < 0.05). Higher plasma ANF concentrations were observed in infants of group A at stage 2 when compared with those at stage 1 (p < 0.1).(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Pediatrics, Kansai Medical University, Osaka, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Kojima
authors.forename: Y
authors.initials: Y
authors.lastname: Isozaki
authors.forename: Y
authors.initials: Y
authors.lastname: Hirata
authors.forename: S
authors.initials: S
authors.lastname: Matsuzaki
authors.forename: Y
authors.initials: Y
authors.lastname: Kobayashi
mesh_terms: D001127:Arginine Vasopressin / Q000652:urine*; D009320:Atrial Natriuretic Factor / Q000097:blood; D003404:Creatinine / Q000652:urine; D005260:Female; D006801:Humans; D007010:Hyponatremia / Q000175:diagnosis / Q000378:metabolism*; D007231:Infant, Newborn; D007232:Infant, Newborn, Diseases / Q000378:metabolism*; D007668:Kidney / Q000378:metabolism; D008297:Male; D009994:Osmolar Concentration; D012964:Sodium / Q000097:blood
chemical_list: D001127:Arginine Vasopressin; D009320:Atrial Natriuretic Factor; D012964:Sodium; D003404:Creatinine