title: Pulmonary deadspace and postoperative outcomes in neonates undergoing stage 1 palliation operation for single ventricle heart disease.
abstract: OBJECTIVE
  Increased pulmonary dead space fraction (VD/VT) has been associated with prolonged mechanical ventilation after surgery for congenital heart disease. The association of VD/VT with clinical outcomes in neonates undergoing stage 1 palliation for single ventricle congenital heart disease has not been reported. We describe changes in VD/VT, differences in VD/VT based on shunt type (right ventricle to pulmonary artery conduit vs modified Blalock-Taussing shunt) and association of VD/VT with postoperative outcomes in patients undergoing stage 1 palliation.
  
  
  METHODS
  Retrospective chart review for demographic, hemodynamics, outcome information, and VD/VT values were collected at 6-hour intervals during the first 48 postoperative hours in neonates undergoing stage 1 palliation. VD/VT was calculated using mixed expired CO2 (PeCO2) obtained from capnography and paired arterial blood gas CO2 values.
  
  
  METHODS
  Cardiac ICU in a tertiary care pediatric hospital.
  
  
  METHODS
  Newborns with single ventricle congenital heart disease undergoing stage 1 palliation during 2003-2004.
  
  
  RESULTS
  Of the 51 patients, 31 had right ventricle to pulmonary artery and 20 had Blalock-Taussing shunt. Although VD/VT was lower in the Blalock-Taussing shunt group over all time points (p = 0.02), maximal VD/VT on day 1 (0.49 ± 0.07) and on day 2 (0.46 ± 0.08) were not different between the shunt groups. VD/VT decreased significantly over time in both shunt groups (p = 0.001 for right ventricle to pulmonary artery; p < 0.001 for Blalock-Taussing shunt). Higher maximal VD/VT during first 48 postoperative hours was independently associated with fewer ventilator (β = -26.6; p = 0.035) and hospital-free days in the first month after stage 1 palliation (β = -40.4; p = 0.002) after adjusting for potential confounders in a multivariable linear regression model.
  
  
  CONCLUSIONS
  Increased pulmonary dead space exists early after stage 1 palliation operation for single ventricle congenital heart disease. Higher VD/VT during the first 48 postoperative hours was associated with longer duration of ventilation and hospital LOS and may be a useful marker of postoperative outcomes in this population.
authors: 1Department of Cardiology, Boston Children's Hospital, Boston, MA. 2Department of Pediatrics, Harvard Medical School, Boston, MA. 3Department of Respiratory Care, Boston Children's Hospital, Boston, MA.
authors: Divya
authors: D
authors: Shakti
authors: Doff B
authors: DB
authors: McElhinney
authors: Kimberlee
authors: K
authors: Gauvreau
authors: Vamsi V
authors: VV
authors: Yarlagadda
authors: Peter C
authors: PC
authors: Laussen
authors: Peter
authors: P
authors: Betit
authors: Mary L
authors: ML
authors: Myrer
authors: Ravi R
authors: RR
authors: Thiagarajan
mesh_terms: D060666:Airway Extubation; D002245:Carbon Dioxide; D006348:Cardiac Surgical Procedures / Q000379:methods; D005260:Female; D006330:Heart Defects, Congenital / Q000503:physiopathology* / Q000601:surgery*; D006352:Heart Ventricles / Q000002:abnormalities* / Q000601:surgery; D006439:Hemodynamics; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D010166:Palliative Care / Q000379:methods*; D010313:Partial Pressure; D011184:Postoperative Period; D011659:Pulmonary Gas Exchange; D013990:Tidal Volume
chemical_list: D002245:Carbon Dioxide