Comparison of a new visual stylet (Discopo)-guided laryngeal mask airway placement vs conventional blind technique: a prospective randomized study

Abstract

Study objective: To compare the ease of laryngeal mask airway (LMA) insertion and fiberoptic view of LMA after placement using the Discopo visual stylet-guided insertion and conventional blind technique.

Design: Prospective, randomized controlled study.

Setting: Operating room in a university hospital.

Patients: One hundred adult patients scheduled for elective surgery under LMA general anesthesia were enrolled.

Interventions: Patients were randomly allocated to 2 groups: GLMA group using a visual stylet-guided technique (n=50) and BLMA group using standard blind technique (n=50). Correct placement of the LMA was confirmed using clinical test along with fiberoptic assessment.

Measurements: Unblinded data were collected about the insertion time, the first attempt success rate, the LMA position adjustment rate, fiberoptic view of LMA anatomical position, hemodynamic responses, and the adverse insertion responses (bucking, breathholding, and laryngospasm). Blinded data were recorded about postoperative airway morbidity (visible blood staining on LMA at removal, sore throat, and hoarseness).

Main results: Insertion was more frequently successful at the first attempt in GLMA than that in BLMA group (100% vs 92%; P=.041). The time taken for establishing effective airway was shorter in GLMA than that in BLMA (54.8 vs 62.9 seconds; P=.001). The patients in BLMA group required more readjustment and reinsertion than those in GLMA group (38% vs 0%; P=.000). The fiberoptic view was significantly better in GLMA group (P<.001). No difference between the 2 groups existed regarding hemodynamic stress responses, incidences of adverse insertion responses, and postoperative airway morbidity.

Conclusions: By direct visualizing the whole process of LMA insertion, the Discopo visual stylet increases the success rate and accuracy rate of LMA placement without increasing hemodynamic stress response or incidences of adverse events.

Keywords: Insertion; Laryngeal mask airway; Visual stylet.