title: Refining the method of therapeutic lung lavage in meconium aspiration syndrome.
abstract: BACKGROUND
  Therapeutic lung lavage is an emerging treatment for meconium aspiration syndrome (MAS), but the ideal fluid volume and lavage technique remain unclear.
  
  
  OBJECTIVE
  To evaluate the impact of suction technique, chest squeeze and aliquot volume on the efficacy of lung lavage in MAS.
  
  
  METHODS
  MAS was induced in ventilated 2-week-old piglets using 4 ml/kg of 20% human meconium. Lung lavage with either two 8 ml/kg saline aliquots (n = 5) or a single 15 ml/kg aliquot (n = 6) was performed soon after meconium instillation. Lavage fluid was recovered by three methods performed in sequence: closed suction via a suction adaptor; open suction with the ventilator disconnected, and open suction with manual vibratory chest squeezing. Return fluid was collected separately with each method. Recovery of meconium and lavage fluid was determined and expressed as a proportion of the amount instilled.
  
  
  RESULTS
  Closed suction resulted in poor meconium and fluid returns, with recovery of meconium being only 5.2 +/- (SD) 2.5% with 2 x 8 ml/kg lavage and 19 +/- 11% with a single 15 ml/kg aliquot. Chest squeeze during suction increased recovery of both meconium and lavage fluid. Overall recovery of instilled meconium was greater with 15 ml/kg lavage (45 +/- 17%) than with two 8 ml/kg aliquots (24 +/- 4.5%, p = 0.028, repeated-measures ANOVA); the corresponding values for return of lavage fluid were 73 +/- 10 and 49 +/- 13%, respectively (p < 0.01).
  
  
  CONCLUSIONS
  Open suction, vibratory chest squeezing and an aliquot volume of 15 ml/kg each improve the efficacy of lung lavage in MAS, and merit inclusion in the lavage technique in clinical trials of this therapy.
authors.affiliation: Neonatal Research Group, Murdoch Children's Research Institute, University of Melbourne, Melbourne, Victoria, Australia. peter.dargaville@dhhs.tas.gov.au
authors.forename: Peter A
authors.initials: PA
authors.lastname: Dargaville
authors.forename: Beverley
authors.initials: B
authors.lastname: Copnell
authors.forename: David G
authors.initials: DG
authors.lastname: Tingay
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Gordon
authors.forename: John F
authors.initials: JF
authors.lastname: Mills
authors.forename: Colin J
authors.initials: CJ
authors.lastname: Morley
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D018893:Bronchoalveolar Lavage / Q000379:methods*; D004195:Disease Models, Animal; D006801:Humans; D007231:Infant, Newborn; D008471:Meconium Aspiration Syndrome / Q000628:therapy*; D012965:Sodium Chloride / Q000008:administration & dosage; D013396:Suction / Q000379:methods; D013552:Swine
chemical_list: D012965:Sodium Chloride