Gastric insufflation during IAC-CPR and standard CPR in a canine model

This study was undertaken to determine the effect of interposed abdominal compressions (IAC) during cardiopulmonary resuscitation (CPR) on gastric insufflation when the airway is not secured with an endotracheal tube. A canine model was used in which a common ventilation pressure was applied to separate cuffed esophageal and tracheal tubes. Gas entering the stomach was collected by a pre-placed gastrostomy tube leading to a bell spirometer. Gas entering the lungs was measured with a Wright Respirometer in series with the endotracheal tube. During standard CPR, measurable gastric gas volume was collected in 28 of 30 trials (mean 215 +/- 93 ml/ventilation). During IAC-CPR, in which abdominal pressure was maintained during ventilation after every 5th chest compression, measurable gastric gas was collected in 15 of 30 trials (mean 40 +/- 11 ml/ventilation). Interposed abdominal compressions as an adjunct to standard CPR may not only be of hemodynamic benefit, but may also reduce the incidence of gastric insufflation and attendant complications.