Closed tracheal suction and fluid aspiration past the tracheal tube. Impact of tube cuff and airway pressure.

BACKGROUND

This study investigated the effect of different tube cuff types and airway pressures on fluid leakage past the tracheal tube cuff during suction with a closed tracheal suction system (CTSS).

METHODS

Unlubricated high-volume, low-pressure tracheal tube cuffs made from polyvinylchloride (PVC) and polyurethane (PU) with a size 7.5 mm internal diameter (ID) were placed in a 22 mm ID artificial trachea connected to a test lung and inflated to 25 or 50 cmH2O of cuff pressure. Positive pressure ventilation (PPV) with peak inspiratory pressures of 15, 20 or 25 cmH2O and positive end expiratory pressures (PEEP) of 5 or 10 cmH2O were used. A CTSS catheter (14 Fr) was attached to the tracheal tube and suction was performed for 5, 10, 15 or 20 s with 200 or 300 cmH2O of negative suction pressures. The volume of fluid leaking across the tube cuff at the end of the suction procedure was measured (mL), and the airway pressure was simultaneously recorded. Fluid leakage and airway pressures during different suction conditions were compared using a Kruskal Wallis test and Mann Whitney test (P<0.05).

RESULTS

The airway pressure drop during suction was similar for both tube cuffs. The PU tube cuff resulted in significantly less fluid leakage (range 0.00-0.12 mL) than the PVC tube cuff (P<0.001). For the PVC tube cuff, fluid leakage at higher cuff pressures was significantly less (P<0.01).Varying PEEP and PIP did not change the fluid leakage or the drop in airway pressure.

CONCLUSION

The use of PU tube cuffs and intermittent transient increases in cuff pressure during suction can effectively reduce fluid leakage past the tracheal tube during closed tracheal suctioning.