title: Interstitial fluid colloid osmotic pressure in healthy children.
abstract: OBJECTIVE
  The colloid osmotic pressure (COP) of plasma and interstitial fluid play important roles in transvascular fluid exchange. COP values for monitoring fluid balance in healthy and sick children have not been established. This study set out to determine reference values of COP in healthy children.
  
  
  METHODS
  COP in plasma and interstitial fluid harvested from nylon wicks was measured in 99 healthy children from 2 to 10 years of age. Nylon wicks were implanted subcutaneously in arm and leg while patients were sedated and intubated during a minor surgical procedure. COP was analyzed in a colloid osmometer designed for small fluid samples.
  
  
  RESULTS
  The mean plasma COP in all children was 25.6 ± 3.3 mmHg. Arbitrary division of children in four different age groups, showed no significant difference in plasma or interstitial fluid COP values for patients less than 8 years, whereas patients of 8-10 years had significant higher COP both in plasma and interstitial fluid. There were no gender difference or correlation between COP in interstitial fluid sampled from arm and leg and no significant effect on interstitial COP of gravity. Prolonged implantation time did not affect interstitial COP.
  
  
  CONCLUSIONS
  Plasma and interstitial COP in healthy children are comparable to adults and COP seems to increase with age in children. Knowledge of the interaction between colloid osmotic forces can be helpful in diseases associated with fluid imbalance and may be crucial in deciding different fluid treatment options.
  
  
  BACKGROUND
  ClinicalTrials.gov NCT01044641.
authors: Department of Pediatrics, Haukeland University Hospital, Bergen, Norway; Department of Clinical Medicine, University of Bergen, Bergen, Norway.
authors: Hans Jørgen Timm
authors: HJ
authors: Guthe
authors: Department of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway.
authors: Marianne
authors: M
authors: Indrebø
authors: Department of Biomedicine, University of Bergen, Bergen, Norway; Department of Occupational Medicine, Hyperbaric Medical Unit, Haukeland University Hospital, Bergen, Norway.
authors: Torbjørn
authors: T
authors: Nedrebø
authors: Department of Clinical Medicine, Faculty of Medicine, Section for Pediatric heart-, lung- and allergic diseases, University of Oslo, Oslo, Norway.
authors: Gunnar
authors: G
authors: Norgård
authors: Department of Biomedicine, University of Bergen, Bergen, Norway.
authors: Helge
authors: H
authors: Wiig
authors: Department of Pediatrics, Haukeland University Hospital, Bergen, Norway; Department of Clinical Science, University of Bergen, Bergen, Norway.
authors: Ansgar
authors: A
authors: Berg
mesh_terms: D000328:Adult; D002648:Child; D002675:Child, Preschool; D003102:Colloids; D045604:Extracellular Fluid / Q000502:physiology*; D005110:Extracellular Space / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D009997:Osmotic Pressure / Q000502:physiology*; D010949:Plasma / Q000502:physiology*; D013048:Specimen Handling / Q000379:methods
chemical_list: D003102:Colloids