title: Tracheal suctioning improves gas exchange but not hemodynamics in asphyxiated lambs with meconium aspiration.
abstract: BACKGROUND
  Current neonatal resuscitation guidelines recommend tracheal suctioning of nonvigorous neonates born through meconium-stained amniotic fluid.
  
  
  METHODS
  We evaluated the effect of tracheal suctioning at birth in 29 lambs with asphyxia induced by cord occlusion and meconium aspiration during gasping.
  
  
  RESULTS
  Tracheal suctioning at birth (n = 15) decreased amount of meconium in distal airways (53 ± 29 particles/mm(2) lung area) compared to no suction (499 ± 109 particles/mm(2); n = 14; P < 0.001). Three lambs in the suction group had cardiac arrest during suctioning, requiring chest compressions and epinephrine. Onset of ventilation was delayed in the suction group (146 ± 11 vs. 47 ± 3 s in no-suction group; P = 0.005). There was no difference in pulmonary blood flow, carotid blood flow, and pulmonary or systemic blood pressure between the two groups. Left atrial pressure was significantly higher in the suction group. Tracheal suctioning resulted in higher Pao2/FiO2 levels (122 ± 21 vs. 78 ± 10 mm Hg) and ventilator efficiency index (0.3 ± 0.05 vs.0.16 ± 0.03). Two lambs in the no-suction group required inhaled nitric oxide. Lung 3-nitrotyrosine levels were higher in the suction group (0.65 ± 0.03 ng/µg protein) compared with the no-suction group (0.47 ± 0.06).
  
  
  CONCLUSIONS
  Tracheal suctioning improves oxygenation and ventilation. Suctioning does not improve pulmonary/systemic hemodynamics or oxidative stress in an ovine model of acute meconium aspiration with asphyxia.
authors.affiliation: Department of Pediatrics, University at Buffalo, Buffalo, New York.
authors.forename: Satyan
authors.initials: S
authors.lastname: Lakshminrusimha
authors.affiliation: Department of Pediatrics, University at Buffalo, Buffalo, New York.
authors.forename: Bobby
authors.initials: B
authors.lastname: Mathew
authors.affiliation: Department of Pediatrics, University at Buffalo, Buffalo, New York.
authors.forename: Jayasree
authors.initials: J
authors.lastname: Nair
authors.affiliation: 1] Department of Pediatrics, University at Buffalo, Buffalo, New York [2] Department of Physiology and Biophysics, University at Buffalo, Buffalo, New York.
authors.forename: Sylvia F
authors.initials: SF
authors.lastname: Gugino
authors.affiliation: Department of Pediatrics, University at Buffalo, Buffalo, New York.
authors.forename: Carmon
authors.initials: C
authors.lastname: Koenigsknecht
authors.affiliation: Department of Pediatrics, University at Buffalo, Buffalo, New York.
authors.forename: Munmun
authors.initials: M
authors.lastname: Rawat
authors.affiliation: Department of Pediatrics, University at Buffalo, Buffalo, New York.
authors.forename: Lori
authors.initials: L
authors.lastname: Nielsen
authors.affiliation: 1] Department of Pediatrics, University at Buffalo, Buffalo, New York [2] Department of Physiology and Biophysics, University at Buffalo, Buffalo, New York.
authors.forename: Daniel D
authors.initials: DD
authors.lastname: Swartz
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D001238:Asphyxia Neonatorum / Q000209:etiology / Q000628:therapy / Q000662:veterinary*; D005453:Fluorescence; D006439:Hemodynamics; D008163:Luminescent Measurements; D008471:Meconium Aspiration Syndrome / Q000150:complications / Q000628:therapy / Q000662:veterinary*; D008863:Microspheres; D011659:Pulmonary Gas Exchange / Q000502:physiology*; D012151:Resuscitation / Q000379:methods / Q000662:veterinary*; D012756:Sheep; D012757:Sheep Diseases / Q000628:therapy*; D013396:Suction / Q000379:methods / Q000662:veterinary*; D014132:Trachea / Q000502:physiology*; D014443:Tyrosine / Q000031:analogs & derivatives / Q000378:metabolism
chemical_list: C002744:3-nitrotyrosine; D014443:Tyrosine