A 72-hour study to test the efficacy and safety of the "Mucus Slurper" in mechanically ventilated sheep

Objective: In patients intubated with endotracheal tubes (ETTs), suctioning is routinely performed to remove mucus from within the ETT and trachea. The Mucus Slurper is a novel ETT with built-in suction ports arranged radially at its tip. We evaluated the safety and efficacy of the Mucus Slurper, compared with conventional tracheal suction, to prevent airway obstruction in sheep with the ETT and trachea oriented below horizontal. Design: Prospective randomized animal study. Setting. Animal research facility at the National Institutes of Health. Subjects: Twelve healthy sheep. Interventions: Sheep were randomized to be intubated with either the Mucus Slurper (study group) or a Hi-Lo Tracheal Tube (Mallinckrodt, St. Louis, MO) (control group) and mechanically ventilated for 72 hrs. In the study group, automatic, timed tracheal aspiration lasted 0.3 secs, was repeated every 2 mins, and was synchronized with the early expiratory phase. In the control group, tracheal suction was performed every 6 hrs or as required. Measurements and Main Results: In the control group, tracheal secretions accumulated progressively within the ETT and the trachea. In the study group, all mucus that reached the tip of the Mucus Slurper was aspirated, keeping the lumen of the ETT, and proximal trachea, free from secretions, In the study group, expiratory water trap protein concentration, a crude index to measure mucus drainage through the ETT, was consistently less than the control group (p < .001). At autopsy, no macroscopic injury to the tracheal mucosa was found in either group. In the study group, the respiratory circuit was less colonized than in the control group. There were no statistically significant differences between the two groups in bacterial colonization of the lungs/bronchi. Conclusions. The Mucus Slurper, combined with orientation of the trachea below horizontal, prevents accumulation of secretions within the lumen of the ETT and trachea, without need for conventional tracheal suctioning.