Insertion of LMA Classic™ with and without digital intraoral manipulation in anesthetized unparalyzed patients

The standard recommended insertion technique for LMA Classic™ requires the insertion of index finger into the oral cavity. Several anesthesiologists are reluctant to do this. We conducted this study to evaluate the modified technique of insertion of LMA Classic™ (not requiring insertion of fingers into the patient's mouth) against the standard index finger insertion technique.

This prospective, randomized, comparative study was conducted on 200 consenting patients. Patients suitable for anesthetic with LMA Classic™ were randomized to standard technique group (standard insertion technique) and modified technique group (technique not requiring digital intraoral manipulation). Laryngeal mask airway (LMA) was inserted by five designated anesthesiologists. Anesthetic protocol was standardized. Time taken to achieve an effective airway, ease of insertion, glottic view obtained through LMA, and incidence of sore throat were assessed.

Patient characteristics and duration of surgery were comparable between the groups. Time to achieve an effective airway was comparable [18.5 (8) s with standard technique and 19.7 (10) s with modified technique; data are mean (standard deviation)]. Ease of insertion (92 easy with standard technique and 91 easy with modified technique), success rate (99% in both the groups), glottic view with fiberoptic bronchoscope, and sore throat incidence (six patients with standard technique and eight patients with modified technique) were comparable. The first attempt success rate was significantly higher with the standard technique (98 patients in the standard technique group and 91 patients in the modified technique group).

LMA Classic™ can be inserted successfully without the need to insert index finger into patient's mouth, though the first attempt success rate is higher with the standard technique.