title: Effects of caffeine on renal and pulmonary function in preterm newborn lambs.
abstract: BACKGROUND
  Caffeine administration is associated with a reduction in bronchopulmonary dysplasia, assisted ventilation, patent ductus arteriosus (DA) and cerebral palsy in preterm infants, but the mechanisms are unknown. Our aim was to determine the effects of acute caffeine administration on renal and pulmonary function in preterm lambs.
  
  
  METHODS
  Lambs were delivered by caesarean section at ~126 days of gestation and ventilated with a tidal volume of 5 ml/kg, 60 breaths/min and 5 cmH(2)O positive end-expiratory pressure. After 30 minutes, lambs received 40 mg/kg caffeine i.v (n=7) or saline (controls; n=6) over 30 minutes and were ventilated for 2 hours.
  
  
  RESULTS
  Arterial caffeine concentrations reached 35.9 ± 7.8 mg/l. Urine output was significantly higher after caffeine treatment than in controls (5.86 ± 1.95 vs 0.76 ± 0.94 ml/kg, area under curve p=0.041). Mean heart rate was significantly higher after caffeine treatment than in controls (211 ± 8 vs 169 ± 15 beats per minute, p<0.05) and remained higher for the experimental period.
  
  
  CONCLUSIONS
  Caffeine did not affect pulmonary artery or DA blood flows or other renal, respiratory or cardiovascular parameters examined. Neonatal caffeine administration increased heart rate and urine output but had little effect on pulmonary function in ventilated preterm lambs.
authors.affiliation: The Ritchie Centre, Monash Institute of Medical Research, Monash University, Clayton, Victoria, Australia .
authors.forename: Kelly J
authors.initials: KJ
authors.lastname: Crossley
authors.forename: Beth J
authors.initials: BJ
authors.lastname: Allison
authors.forename: Graeme R
authors.initials: GR
authors.lastname: Polglase
authors.forename: Colin J
authors.initials: CJ
authors.lastname: Morley
authors.forename: Richard
authors.initials: R
authors.lastname: Harding
authors.forename: Peter G
authors.initials: PG
authors.lastname: Davis
authors.forename: Timothy J M
authors.initials: TJ
authors.lastname: Moss
authors.forename: Stuart B
authors.initials: SB
authors.lastname: Hooper
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002110:Caffeine / Q000008:administration & dosage / Q000494:pharmacology*; D004373:Ductus Arteriosus / Q000187:drug effects; D005260:Female; D005865:Gestational Age; D006339:Heart Rate / Q000187:drug effects; D007262:Infusions, Intravenous; D007668:Kidney / Q000187:drug effects* / Q000503:physiopathology; D008168:Lung / Q000098:blood supply / Q000187:drug effects* / Q000503:physiopathology; D008297:Male; D047928:Premature Birth; D011651:Pulmonary Artery / Q000187:drug effects; D012119:Respiration / Q000187:drug effects; D012121:Respiration, Artificial; D012756:Sheep; D013997:Time Factors; D014554:Urination / Q000187:drug effects
chemical_list: D002110:Caffeine