CRICOID PRESSURE IMPEDES PLACEMENT OF THE LARYNGEAL MASK AIRWAY AND SUBSEQUENT TRACHEAL INTUBATION THROUGH THE MASK

We have studied 40 patients to see if cricoid pressure affects the suc cess rate of ventilation through, and the position of, the laryngeal m ask and subsequent fibrescope-aided tracheal intubation. Adequate vent ilation of the lungs was produced through the laryngeal mask in 19 of 20 patients in the control group, but in only 10 of 20 patients in the cricoid pressure group (P < 0.002). The laryngeal mask was positioned correctly in 16 patients in the control group, but in only two patien ts in the cricoid pressure group (P < 0.001). Tracheal intubation was accomplished in 19 patients in the control group, but in only three pa tients in the cricoid pressure group (P < 0.001). Release of cricoid p ressure after placement of the laryngeal mask improved the view of the glottis, but tracheal intubation was still difficult because of laryn geal deviation. These results show that cricoid pressure impedes place ment of the laryngeal mask and subsequent fibrescope-aided tracheal in tubation.