title: Hemodynamic analysis in infants with late-onset circulatory collapse.
abstract: BACKGROUND
  Late-onset circulatory collapse (LCC) is a disorder in which blood pressure decreases and oliguria suddenly occurs in preterm infants who have survived the acute stage, leading to shock, without contributing underlying factors. In order to evaluate hemodynamic changes during LCC, the correlation between myocardial functions and organ blood flow was investigated with echography.
  
  
  METHODS
  Seven very-low-birthweight infants were given a diagnosis of LCC during the study period. Cardiovascular and organ flow parameters of the infants were recorded prospectively, once a week, and compared with eight control very-low-birthweight infants with matching gestational age. Echographic study was performed before LCC, at the onset of LCC, and after LCC among infants with LCC.
  
  
  RESULTS
  A significant increase in ejection fraction and a significant decrease in end systolic wall stress were observed in infants with the LCC condition. At the same time, the mean blood flow velocity increased significantly in the superior mesenteric artery, while it decreased in the anterior cerebral artery. Systolic blood flow velocity increased and mean velocity was maintained in the renal artery during LCC.
  
  
  CONCLUSIONS
  LCC is a distributive shock, characterized by a hyperdynamic state and decreased afterload. Echographic examination of organ flow during LCC is useful in understanding the pathophysiology of the disorder.
authors.affiliation: Department of Neonatology, Maternal and Perinatal Center, Tokyo Women's Medical University, Tokyo, Japan.
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Washio
authors.forename: Atsushi
authors.initials: A
authors.lastname: Uchiyama
authors.forename: Hidehiko
authors.initials: H
authors.lastname: Nakanishi
authors.forename: Satsuki
authors.initials: S
authors.lastname: Totsu
authors.forename: Kenichi
authors.initials: K
authors.lastname: Masumoto
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kusuda
mesh_terms: D005260:Female; D005500:Follow-Up Studies; D005865:Gestational Age; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000502:physiology*; D019102:Infant, Very Low Birth Weight / Q000502:physiology; D008297:Male; D011379:Prognosis; D011446:Prospective Studies; D012769:Shock / Q000000981:diagnostic imaging / Q000503:physiopathology*; D014463:Ultrasonography
keywords: distributive shock; late-onset circulatory collapse; periventricular leukomalacia; preterm infants; splanchnic blood flow