Gianluigi Li Bassi, MD, PhD; Nestor Luque, MD; Joan Daniel Martí, PhD, RPT; Eli Aguilera Xiol, MSc; Marta Di Pasquale, MD; Valeria Giunta, MD; Talitha Comaru, PhD, RPT; Montserrat Rigol, DVM, PhD; Silvia Terraneo, MD; Francesca De Rosa, MD; Mariano Rinaudo, MD; Ernesto Crisafulli, MD, PhD, FCCP; Rogelio Cesar Peralta Lepe, MD; Carles Agusti, MD, PhD; Carmen Lucena, MD; Miguel Ferrer, MD, PhD; Laia Fernández, PhD; Antoni Torres, MD, PhD, FCCP CHEST May 2015; 147(5): 1327-1335
BACKGROUND: Improvements in the design of the endotracheal tube (ETT) have been achieved in recent years. We evaluated tracheal injury associated with ETTs with novel high-volume low-pressure (HVLP) cuffs and subglottic secretions aspiration (SSA) and the effects on mucociliary clearance (MCC).
METHODS: Twenty-nine pigs were intubated with ETTs comprising cylindrical or tapered cuffs and made of polyvinylchloride (PVC) or polyurethane. In specific ETTs, SSA was performed every 2 h. Following 76 h of mechanical ventilation, pigs were weaned and extubated. Images of the tracheal wall were recorded before intubation, at extubation, and 24 and 96 h thereafter through a fluorescence bronchoscope. We calculated the red-to-green intensity ratio (R/G), an index of tracheal injury, and the green-plus-blue (G+B) intensity, an index of normalcy, of the most injured tracheal regions. MCC was assessed through fluoroscopic tracking of radiopaque markers. After 96 h from extubation, pigs were killed, and a pathologist scored injury.
RESULTS: Cylindrical cuffs presented a smaller increase in R/G vs tapered cuffs (P = .011). Additionally, cuffs made of polyurethane produced a minor increase in R/G (P = .012) and less G+B intensity decline (P = .022) vs PVC cuffs. Particularly, a cuff made of polyurethane and with a smaller outer diameter outperformed all cuffs. SSA-related histologic injury ranged from cilia loss to subepithelial inflammation. MCC was 0.9 ± 1.8 and 0.4 ± 0.9 mm/min for polyurethane and PVC cuffs, respectively (P < .001).
CONCLUSIONS: HVLP cuffs and SSA produce tracheal injury, and the recovery is incomplete up to 96 h following extubation. Small, cylindrical-shaped cuffs made of polyurethane cause less injury. MCC decline is reduced with polyurethane cuffs.
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