title: Levels of catecholamines, arginine vasopressin and atrial natriuretic peptide in hypotensive extremely low birth weight infants in the first 24 hours after birth.
abstract: BACKGROUND
  Extremely low birth weight infants (ELBWI) often suffer from severe hypotension in the early neonatal period. However, few previous studies have ever revealed plasma levels of vasoactive substances which regulate the cardiovascular system in ELBWI.
  
  
  OBJECTIVE
  To study plasma levels of vasoactive substances in ELBWI with hypotension during the first 24 h of life.
  
  
  METHODS
  22 ELBWI with hypotension (gestational age 26.4 +/- 1.9 weeks; birth weight 751 +/- 135 g) were involved in the study. After initial volume therapy, the infants were arbitrarily divided into two groups depending on requirement of dopamine dosage: severe hypotension group (SH; dopamine >10 microg/kg/min, n = 9) and mild hypotension group (MH; dopamine <or=10 microg/kg/min, n = 13). Plasma levels of dopamine, norepinephrine, epinephrine, arginine vasopressin, and atrial natriuretic peptide were measured at admission and at 24 h after birth.
  
  
  RESULTS
  Infants in the SH group had higher plasma dopamine than infants in the MH group both at admission (median; range: 14,410; 224-46,770 vs. 7,900; 32-21,220 pg/ml, p < 0.05) and at 24 h (80,920; 494-146,100 vs. 25,680; 10,130-63,180 pg/ml; p < 0.05). The norepinephrine/dopamine ratio (median; range) was lower in the SH group than in the MH group at admission (0.3; 0.0-1.0 vs. 1.1; 0.1-25.1; p < 0.01). Plasma levels of atrial natriuretic peptide or arginine vasopressin were not different between the two groups.
  
  
  CONCLUSIONS
  ELBWI with SH may have decreased conversion of dopamine to norepinephrine. We speculate that this mechanism may contribute to development of SH in ELBWI.
authors.affiliation: Division of Neonatal Medicine, Center for Maternal, Fetal and Neonatal Medicine, Saitama Medical Center, Saitama Medical University, Kawagoe, Saitama, Japan. s_ezaki@saitama-med.ac.jp
authors.forename: Shoichi
authors.initials: S
authors.lastname: Ezaki
authors.forename: Keiji
authors.initials: K
authors.lastname: Suzuki
authors.forename: Clara
authors.initials: C
authors.lastname: Kurishima
authors.forename: Masumi
authors.initials: M
authors.lastname: Miura
authors.forename: Koichi
authors.initials: K
authors.lastname: Moriwaki
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Arakawa
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Kunikata
authors.forename: Hisanori
authors.initials: H
authors.lastname: Sobajima
authors.forename: Masanori
authors.initials: M
authors.lastname: Tamura
mesh_terms: D001127:Arginine Vasopressin / Q000097:blood*; D009320:Atrial Natriuretic Factor / Q000097:blood*; D002316:Cardiotonic Agents / Q000627:therapeutic use; D002395:Catecholamines / Q000097:blood*; D004298:Dopamine / Q000627:therapeutic use; D004305:Dose-Response Relationship, Drug; D006801:Humans; D007022:Hypotension / Q000097:blood* / Q000188:drug therapy / Q000503:physiopathology; D052577:Infant, Extremely Low Birth Weight / Q000097:blood*; D007231:Infant, Newborn
chemical_list: D002316:Cardiotonic Agents; D002395:Catecholamines; D001127:Arginine Vasopressin; D009320:Atrial Natriuretic Factor; D004298:Dopamine