Cardiovascular changes after extraglottic airway insertion: a prospective, randomized comparison between the laryngeal mask or the new PAXpress.

Study Objective: To compare hemodynamic responses induced with the new extraglottic airway, PAXpress, and the classic Laryngeal Mask Airway (LMA).

Design: Prospective, randomized study.

Setting: Anesthesia department of a university teaching hospital.

Patients: 70 ASA physical status I and II patients, aged 18 to 65 years, scheduled to receive general anesthesia for extraabdominal procedures of short duration.

Interventions: Patients were randomly allocated to receive either a LMA (n = 35) or a PAXpress (n = 35) placement. After midazolam premedication (0.05 mg kg-1) and general anesthesia induction (propofol 2.5 mg kg-1, and fentanyl 1 microg kg-1) the airways were placed according to manufacturer instructions; then general anesthesia was maintained with a 2% sevoflurane concentration and an air/oxygen mixture.

Measurements And Main Results: Arterial blood pressure [both systolic (SBP) and diastolic (DBP)] and heart rate (HR) values were recorded immediately before airway placement, immediately after airway placement, then every 1 minute during the first 5 minutes. During the first 5 minutes after airway insertion, both SBP and DBP values were higher with the PAXpress than the LMA (repeated measures analysis of variance:p = 0.02 and p = 0.006, respectively), whereas no differences were reported in HR values. Also, the maximum percentage increase in both SBP and DBP values was larger with PAXpress [+19% (range: -19% to +80%) for SBP and +26% (range: -17% to +96%) for DBP] than the LMA [+9% (range: -30% to +90%) for SBP and +10% (range: -30% to +92%) for DBP] (p = 0.006 and p = 0.001, respectively).

Conclusions: Although further studies are required to evaluate safety and airway trauma of this new extraglottic airway, placing the PAXpress produces more marked changes in hemodynamic variables as compared with those produced by the LMA.