title: Prospective sonographic evaluation of fentanyl side effects on the neonatal gallbladder.
abstract: OBJECTIVE
  In an effort to minimise the stress and pain of mechanically ventilated neonates, the application of opioids has increased markedly. Abdominal adverse effects of opioid analgesics are constipation and increased pressure in the biliary system. Our aim was to evaluate the impact of continuous intravenous infusion of fentanyl on the volume of the neonatal gallbladder and to assess potential gastrointestinal side effects.
  
  
  METHODS
  We prospectively matched pairs of 40 mechanically ventilated neonates (28-42 gestational weeks) under total parenteral nutrition and midazolam sedation. One group (20 patients) received continuous fentanyl infusions (dose 0.5-2 microg kg(-1) h(-1)) the other group (20 patients) served as controls. Sonographic measurements of gallbladder length, depth and width were performed to calculate gallbladder volume using the ellipsoid method. Repeated ultrasound images, date of meconium release and serum bilirubin levels were documented.
  
  
  RESULTS
  Fentanyl application was not associated with gallbladder sludge/stones, gallbladder hydrops, hyperbilirubinemia or prolonged meconium release. Neonatal gallbladder length, width and volume did not differ significantly (data expressed as mean, standard deviation, median, interquartile range: length (cm) 3.16+/-0.68, 3.3, 0.675 vs 3.06+/-0.62, 3.3, 1.1; P=0.645; width (cm) 1.02+/-0.23, 1.0, 0.28 vs 0.89+/-0.27, 0.9, 0.38, P=0.12; volume (cm(3)) 1.52+/-0.67, 1.7, 0.86 vs 1.22+/-0.77, 1.09, 1.19, P=0.20).
  
  
  CONCLUSIONS
  In our study fentanyl caused no major complications in the biliary system and intestine of ventilated preterm and term neonates. Sonographic investigations of the gallbladder under fentanyl treatment may be dispensable. Further investigations are required to assess adverse gastrointestinal effects.
authors.affiliation: Department of Neonatology, Children's Hospital, University of Cologne, Kerpenerstrasse 62, 50937, Cologne, Germany. beate.schmidt@uk-koeln.de
authors.forename: Beate
authors.initials: B
authors.lastname: Schmidt
authors.forename: Bernhard
authors.initials: B
authors.lastname: Roth
authors.forename: Hartmut
authors.initials: H
authors.lastname: Stützer
authors.forename: Gabriele
authors.initials: G
authors.lastname: Benz-Bohm
mesh_terms: D000367:Age Factors; D018686:Anesthetics, Intravenous / Q000008:administration & dosage / Q000009:adverse effects; D001663:Bilirubin / Q000097:blood; D001724:Birth Weight; D003627:Data Interpretation, Statistical; D005260:Female; D005283:Fentanyl / Q000008:administration & dosage / Q000009:adverse effects*; D005704:Gallbladder / Q000000981:diagnostic imaging* / Q000187:drug effects / Q000473:pathology; D005865:Gestational Age; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature; D007262:Infusions, Intravenous; D008297:Male; D008470:Meconium / Q000378:metabolism; D009929:Organ Size / Q000187:drug effects; D010288:Parenteral Nutrition; D010865:Pilot Projects; D011446:Prospective Studies; D012121:Respiration, Artificial; D012127:Respiratory Distress Syndrome, Newborn / Q000628:therapy*; D016037:Single-Blind Method; D013997:Time Factors; D014463:Ultrasonography
chemical_list: D018686:Anesthetics, Intravenous; D001663:Bilirubin; D005283:Fentanyl