Polyurethane does not protect better than polyvinyl cuffed tracheal tubes from microaspirations

Area of Science:

• Medical Devices
• Respiratory Care
• Infection Prevention

Background:

• Mechanically ventilated patients risk ventilator-associated pneumonia (VAP) from subglottic secretion microaspiration.
• Endotracheal tube (ETT) cuffs, typically polyvinyl, may allow microaspiration.
• A novel polyurethane ETT cuff aims to reduce these leakages.

Purpose of the Study:

• To compare the tracheal sealing efficacy of a new polyurethane ETT cuff versus a standard polyvinyl ETT cuff.
• To evaluate the potential of ETT cuff material to prevent microaspiration.

Main Methods:

• A randomized trial compared polyvinyl HI-LO Evac® and polyurethane SEALGUARD Evac® ETTs in 29 patients.
• Cuff pressure was maintained at 30 cmH2O, with plateau pressure ≤30 cmH2O.
• Technetium-99m-labeled diethylenetriamine penta-acetic acid (99mTc-DTPA) was injected above the cuff, and tracheal radioactivity was measured over 12 hours.

Main Results:

• Overall, 38% of patients experienced leakages (5/16 polyurethane, 6/13 polyvinyl; P=NS).
• Leakages were significantly more frequent in female patients (7/8) than male patients (4/21) (P<0.001).
• Microaspiration decreased with larger ETTs (size 9 vs. ≤8.5: 24% vs. 75%; P=0.01).

Conclusions:

• Both tested ETT cuffs demonstrated limited effectiveness in preventing microaspiration.
• Further research is needed to improve ETT designs for VAP prevention.
• ETT size may be a more critical factor than cuff material in reducing microaspiration.