LEAKAGE OF FLUID PAST THE TRACHEAL TUBE CUFF IN A BENCHTOP MODEL

We have assessed a range of high volume, low pressure (HVLP) cuffed tr acheal tubes in a benchtop model, for leakage of fluid from above the cuff to the model trachea below, during various ventilatory modes. Rap id leakage occurred in the model during all modes of ventilation, unle ss tracheal pressure was greater than the height of fluid in the colum n above the cuff. This leakage occurred preferentially down longitudin al folds that occur in the HVLP cuff wall. This model suggests that, i f a longitudinal fold within the cuff wall is patent, then the possibi lity exists of subglottic to tracheal leakage.