The effect of cricoid pressure on preventing gastric insufflation in infants and children.

BACKGROUND: The use of cricoid pressure for the possible prevention of regurgitation of gastric contents during induction of anesthesia in both adults and children has been recommended. However, equally important is the technique in possibly preventing insufflation of gas into the stomach. This study was designed to determine the efficacy of cricoid pressure application in preventing gastric gas insufflation in pediatric patients and to determine the airway pressure at which gas entered the stomach (pop-off point).
METHODS: Fifty-nine patients, 2 weeks to 8 yr of age, physical status 1-4, scheduled for elective surgery, received an inhalational induction of anesthesia with halothane, N2O, and O2. A single observer used a stethoscope to auscultate over the upper abdomen for any air entry. In study I (without paralysis), the proximal airway pressure was slowly increased by gradually closing the pop-off valve on the anesthesia machine until gas was heard entering the stomach (pop-off point) or until the peak inspiratory pressure (PIP) reached 40 cm H2O. Thereafter, the pressurization procedure was repeated three times, altering the application and removal of cricoid pressure. The same patients were then paralyzed (study II), and the stomach evacuated before commencing an identical pressurization sequence with and without cricoid pressure.
RESULTS: Appropriately applied cricoid pressure was 100% effective in preventing gas insufflation into the stomach of all children up to 40 cm H2O PIP with and without paralysis. In addition, paralysis significantly decreased the median pop-off point in any given patient.
CONCLUSIONS: Appropriate application of cricoid pressure prevents gastric gas insufflation during airway management via mask up to 40 cm H2O PIP in infants and children. An additional benefit of cricoid pressure occurs in paralyzed patients in whom gastric insufflation occurs at lower inflation pressures.