title: Application of tracheal gas insufflation to acute unilateral lung injury in an experimental model.
abstract: In unilateral lung injury, application of global positive end-expiratory pressure (PEEP) may cause overdistension of normal alveoli and redistribution of blood flow to diseased lung areas, thereby worsening oxygenation. We hypothesized that selective application of tracheal gas insufflation (TGI) will recruit the injured lung without causing overdistension of the normal lung. In eight anesthetized dogs, left lung saline lavage was performed until Pa(O(2))/FI(O(2)) fell below 100 mm Hg. Then, the dogs were reintubated with a Univent single lumen endotracheal tube that incorporates an internal catheter to provide TGI. After injury, increasing PEEP from 3 to 10 cm H(2)O did not change gas exchange, hemodynamics, or lung compliance. Selective TGI, while keeping end-expiratory lung volume (EELV) constant, improved Pa(O(2))/FI(O(2)) from 212 +/- 43 to 301 +/- 38 mm Hg (p < 0.01) while Pa(CO(2)) and airway pressures decreased (p < 0.01). During selective TGI, reducing tidal volume to 5.2 ml/kg while keeping EELV constant, normalized Pa(CO(2)), did not affect Pa(O(2))/FI(O(2)), and decreased end-inspiratory plateau pressure from 16.6 +/- 1.0 to 11.9 +/- 0.5 cm H(2)O (p < 0.01). In unilateral lung injury, we conclude that selective TGI (1) improves oxygenation at a lower pressure cost as compared with conventional mechanical ventilation, (2) allows reduction in tidal volume without a change in alveolar ventilation, and (3) may be a useful adjunct to limit ventilator-associated lung injury.
authors.affiliation: Department of Pulmonary and Critical Care Medicine, University of Minnesota, Regions Hospital, St. Paul, Minnesota, USA. lblanch@cspt.es
authors.forename: L
authors.initials: L
authors.lastname: Blanch
authors.forename: T E
authors.initials: TE
authors.lastname: Van der Kloot
authors.forename: A M
authors.initials: AM
authors.lastname: Youngblood
authors.forename: G
authors.initials: G
authors.lastname: Murias
authors.forename: A
authors.initials: A
authors.lastname: Naveira
authors.forename: A B
authors.initials: AB
authors.lastname: Adams
authors.forename: P V
authors.initials: PV
authors.lastname: Romero
authors.forename: A
authors.initials: A
authors.lastname: Nahum
mesh_terms: D000818:Animals; D001784:Blood Gas Analysis; D004195:Disease Models, Animal; D004285:Dogs; D006439:Hemodynamics; D007327:Insufflation / Q000295:instrumentation / Q000379:methods*; D010102:Oxygen Inhalation Therapy / Q000295:instrumentation / Q000379:methods*; D011175:Positive-Pressure Respiration / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D011659:Pulmonary Gas Exchange; D011859:Radiography; D012128:Respiratory Distress Syndrome / Q000139:chemically induced / Q000000981:diagnostic imaging / Q000378:metabolism / Q000503:physiopathology / Q000628:therapy*; D015656:Respiratory Mechanics; D012965:Sodium Chloride; D007507:Therapeutic Irrigation; D013990:Tidal Volume; D014132:Trachea
chemical_list: D012965:Sodium Chloride