The PAxpress™ is an effective ventilatory device but has an 18% failure rate for flexible lightwand-guided tracheal intubation in anesthetized paralyzed patients

Abstract

Purpose: the PAxpress™ is a new, single-use, extraglottic airway device. We evaluate: 1) insertion success rates; 2) airway sealing pressure, ventilatory capability and calculated mucosal pressures (in vitro minusin vivo intracuff pressure) at 30–60 mL cuff inflation volume; 3) the feasibility of lightwand-guided trachéal intubation; and 4) the incidence of mucosal trauma.

Methods: ninety anesthetized, paralyzed adults were studied. Airway management was by senior anesthesiologists with no prior experience with the PAX, but considerable experience with extraglottic airway devices and the flexible-lightwand.

Results insertion was successful at the first attempt in 95.5% (86/90) and at the second attempt in 4.5% (4/90). Mean ± SD airway sealing pressure at 30, 40, 50 and 60 mL cuff inflation volume was 27 ± 8, 29 ± 9, 32 ± 9 and 35 ± 7 cm H2O respectively; expired tidal volume at airway sealing pressure was 16 ± 6, 18 ± 6, 19 ± 5 and 19 ± 6 mL·kg−1; and calculated mucosal pressure was 38 ± 14, 55 ± 20, 56 ± 19 and 57 ± 20 cm H2O. Airway sealing pressure, expired tidal volume at airway sealing pressure and calculated mucosal pressures increased with cuff inflation volume (all:P < 0.0002). Esophageal leak was detected in 9% (8/90), but only at peak pressures ≥ 35 cm H2O and cuff inflation volumes ≥ 40 mL. Lightwand-guided intubation was successful in 82% (74/90) of patients. Mild, moderate and severe blood staining was detected in 40%(36/90), 15%(13/90) and 1% (1/90) respectively. Blood staining was more frequent after adjusting maneuvers (22/54vs 32/36,P = 0.002).

Conclusion: the PAX has a high insertion success rate and is an effective ventilatory device with a low risk of gastric insufflation, but has a moderately high failure rate for lightwand-guided intubation and is associated with a relatively high incidence of mucosal trauma. Mucosal pressures may exceed pharyngeal perfusion pressure.