title: Effect of delayed sternal closure after cardiac surgery on respiratory function in ventilated infants.
abstract: OBJECTIVE
  Studies examining the effect of sternal closure on respiratory function have not been published, and currently there is little evidence to guide ventilation management immediately after closure. The aim of this study was to establish the impact of delayed sternal closure on expired tidal volume, respiratory system compliance, and CO2 elimination immediately after the procedure in infants who had undergone open heart surgery.
  
  
  METHODS
  Prospective study of respiratory function before and after delayed sternal closure.
  
  
  METHODS
  Cardiac intensive care unit, Great Ormond Street Hospital, London.
  
  
  METHODS
  Seventeen infants (median age, 2 wks) with open median sternotomy incisions after cardiac surgery. Data were collected between August 1998 and March 2000.
  
  
  METHODS
  Respiratory function was measured continuously for 30 mins before and after delayed sternal closure in paralyzed ventilated infants.
  
  
  RESULTS
  Four babies were excluded from the study because they required either immediate increase in ventilation after delayed sternal closure (n = 3) or removal of pericardial blood collection (n = 1). In the remaining 13 infants, expired tidal volume and CO2 elimination decreased significantly (p < .005) by a mean of 17% and 29%, respectively, after sternal closure. In five of the remaining 13 patients, the magnitude of tracheal tube leak increased by > or = 10% after delayed sternal closure, thereby invalidating recorded changes in respiratory system compliance. Of the eight infants in whom there was a minimal change in leak, respiratory system compliance decreased significantly (p < .05) by a mean of 19%.
  
  
  CONCLUSIONS
  This study supports the hypothesis that respiratory function may be compromised after delayed sternal closure and that ventilatory support should be increased to counteract the anticipated decrease in tidal volume. Extra vigilance should be applied in monitoring blood gases after delayed sternal closure to assess clinical responses to sternal closure or changes in ventilatory support. Accurate assessment of change in respiratory system compliance after any therapeutic intervention may be precluded by changes in tracheal tube leak during the procedure.
authors.affiliation: Physiotherapy Department, Great Ormond Street Hospital for Children NHS Trust, London, UK.
authors.forename: E
authors.initials: E
authors.lastname: Main
authors.forename: M J
authors.initials: MJ
authors.lastname: Elliott
authors.forename: M
authors.initials: M
authors.lastname: Schindler
authors.forename: J
authors.initials: J
authors.lastname: Stocks
mesh_terms: D003422:Critical Care; D005260:Female; D006330:Heart Defects, Congenital / Q000601:surgery*; D006439:Hemodynamics; D006801:Humans; D007231:Infant, Newborn; D007363:Intensive Care Units, Neonatal; D008297:Male; D011184:Postoperative Period; D012119:Respiration; D012121:Respiration, Artificial; D013249:Sternum / Q000601:surgery; D013997:Time Factors; D016896:Treatment Outcome