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

Abstract

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 minus in vivo intracuff pressure) at 30-60 mL cuff inflation volume; 3) the feasibility of lightwand-guided tracheal intubation; and 4) the incidence of mucosal trauma. 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. 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 H(2)O 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 H(2)O. Airway sealing pressure, expired tidal volume at airway sealing pressure and calculated mucosal pressures increased with cuff inflation volume (all: P < or = 0.0002). Esophageal leak was detected in 9% (8/90), but only at peak pressures > or = 35 cm H(2)O and cuff inflation volumes > or = 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 (22/54 vs 32/36, P = 0.002). 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.