Editor—As some of the people responsible for setting resuscitation guidelines, we are interested in the case report of Haslam et al describing gastric rupture after use of the laryngeal mask airway during cardiopulmonary resuscitation.1
There is a risk of gastric inflation with all airway and ventilation techniques during cardiopulmonary resuscitation. Positive pressure ventilation via a laryngeal mask airway can cause gastric inflation, particularly if the airway is not positioned correctly and if the inspiratory pressure exceeds 20 cm H2O.2-4 Most gas leaking from the airway escapes into the pharynx to exit through the mouth.3
In the case described the laryngeal mask airway is not the most likely cause of gastric rupture. The patient was given seven minutes of cardiopulmonary resuscitation by a bystander: chest compressions alone can cause gastric rupture, particularly if delivered too low on the sternum or upper abdomen. Furthermore, mouth to mouth or bag-valve mask ventilation is much more likely to cause gastric inflation than ventilation with a laryngeal mask airway: incorrect alignment of the airway will cause gastric inflation because the mask or rescuer's mouth prevents gas escaping through the patient's mouth, and high airway pressures will be transmitted entirely to the oesophagus.4 For this reason, using an laryngeal mask airway instead of a face mask to ventilate the lungs during cardiopulmonary resuscitation reduces the incidence of regurgitation.5
The advice given in the advanced life support course manual to attempt to undertake continuous chest compressions, uninterrupted during ventilation through the laryngeal mask airway, is based on evidence that even a brief pause in chest compressions causes a significant reduction in coronary perfusion pressure. If excessive gas leakage occurs, chest compressions will have to be interrupted to enable ventilation of the lungs. The precise risk of gastric inflation when using the laryngeal mask airway under these circumstances is unknown and should be studied.
The other four authors of this letter are David A Gabbott, consultant anaesthetist, Department of Anaesthetics, Gloucestershire Hospitals NHS Trust, Gloucester GL1 3NN; Andrew Lockey, consultant in accident and emergency medicine, Calderdale Royal Hospital, Salterhebble, Halifax HX3 0PW; Sarah Mitchell, director, Resuscitation Council (UK), London WC1H 9HR; Jasmeet Soar, consultant in anaesthesia and intensive care medicine, Southmead Hospital, North Bristol NHS Trust, Bristol BS10 5NB.
Competing interests: The authors are members of the Resuscitation Council (UK).
References
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