title: Lateral versus anterior thoracic thrusts in the generation of airway pressure in anaesthetised pigs.
abstract: OBJECTIVE
  Anterior chest thrusts (with the subject sitting or standing and thrusts applied to the lower sternum) are recommended by the Australian Resuscitation Council as part of the sequence for clearing upper airway obstruction by a foreign body. Lateral chest thrusts (with the victim lying on their side) are no longer recommended due to a lack of evidence. We compared anterior, lateral chest and abdominal thrusts in the generation of airway pressures using a suitable animal model.
  
  
  METHODS
  This was a repeated-measures, cross-over, clinical trial of eight anaesthetised, intubated, adult pigs. For each animal, ten trials of each technique were undertaken with the upper airway obstructed. A chest/abdominal pressure transducer, a pneumotachograph and an intra-oesophageal balloon catheter recorded chest/abdominal thrust, expiratory air flows, airway and intrapleural pressures, respectively.
  
  
  RESULTS
  The mean (SD) thrust pressures generated for the anterior, lateral and abdominal techniques were 120.9 (11.0), 135.2 (20.0), and 142.4 (27.3)cmH(2)O, respectively (p<0.0001). The mean (SD) peak expiratory airway pressures were 6.5 (3.0), 18.0 (5.5) and 13.8 (6.7)cmH2O, respectively (p<0.0001). The mean (SD) peak expiratory intrapleural pressures were 5.4 (2.7), 13.5 (6.2) and 10.3 (8.5)cmH(2)O, respectively (p<0.0001). At autopsy, no rib, intra-abdominal or intra-thoracic injury was observed.
  
  
  CONCLUSIONS
  Lateral chest and abdominal thrust techniques generated significantly greater airway and pleural pressures than the anterior thrust technique. We recommend further research to provide additional evidence that may inform management guidelines for clearing foreign body upper airway obstruction.
authors.affiliation: Divers Alert Network Asia-Pacific, Australia. johnl@danasiapacific.org
authors.forename: John
authors.initials: J
authors.lastname: Lippmann
authors.forename: David McD
authors.initials: DM
authors.lastname: Taylor
authors.forename: Ron
authors.initials: R
authors.lastname: Slocombe
authors.forename: Christine F
authors.initials: CF
authors.lastname: McDonald
authors.forename: Tony
authors.initials: T
authors.lastname: Walker
authors.forename: Gary
authors.initials: G
authors.lastname: Nolan
mesh_terms: D000402:Airway Obstruction / Q000628:therapy*; D000818:Animals; D004638:Emergency Treatment / Q000379:methods*; D059746:Heimlich Maneuver; D023421:Models, Animal; D011312:Pressure; D013552:Swine