Comparative study of hemodynamic responses to orotra- cheal intubation with intubating laryngeal mask airway and direct laryngoscope

Background Intubating laryngeal mask airway （ILMA） offers a new approach for orotracheal intubation and is expected to produce less cardiovascular stress responses. However, the available studies provide inconsistent results. The purpose of this study was to identify whether there is a clinically relevant difference in hemodynamic responses to orotracheal intubation by using ILMA and direct laryngoscope （DLS）. Methods A total of 53 adult patients, ASA physical status I-II, scheduled for elective plastic surgery under general anesthesia requiring the orotracheal intubation, were randomly allocated to either DLS or ILMA groups. After a standard intravenous anesthesia induction, orotracheal intubation was performed. Noninvasive blood pressure and heart rate were recorded before （baseline values） and after anesthesia induction （post-induction values）, at intubation and every minute for the first 5 minutes after intubation. The data were analyzed using Chisquare test, paired and unpaired Student＇s t test, and repeated-measures analysis of variance as appropriate. Results The mean intubation time in the ILMA group was longer than that in the DLS group （P〈0.05）. The blood pressure and heart rate increased significantly after intubation in the two groups compared to the postinduction values （P〈0.05）, but the maximum value of blood pressure during the observation did not exceed the baseline value, while the maximum value of heart rate was higher than the baseline （P〈0.05）. During the observation, there were no significant differences in blood pressure and heart rate among each time point and in the maximum values between the two groups. Conclusions Orotracheal intubations by using ILMA and DLS produce similar hemodynamic response. ILMA has no advantage in attenuating the hemodynamic responses to orotracheal intubation compared with DLS.

USE OF A BLIND INTUBATION DEVICE FOR NASOTRA-CHEAL INTUBATION IN TEMPOROMANDIBULAR JOINT ANKYLOSIS

Objective To evaluate light-guided tracheal intubation using blind intubation device (BID) in adult patients with temporomandibular joint ankylosis. Methods Twenty adult patients, American Society of Anesthesiologists (ASA) physical status Ⅰ or Ⅱ, with temporomandibular joint ankylosis were selected for awake blind nasal intubation. The patients were prepared with nasal decongestants and inhaled 100% oxygen for 3min, then fentanyl (2μg/kg) and midazolam (1-5 mg) were intravenously injected for sedation. Topical anaesthesia for the glottis was performed by using cricothyroid injection of local anaesthesia. A blind intubation device was used to help blind nasal intubation. Three attempts of blind nasal intubation were permitted, otherwise, fiberoptic bronchoscope (FOB) intubation was utilized considering the failure of blind intubation. During the procedure, heart rate, mean arterial pressure, and pulse oxygen saturation (SpO2) were measured. Results Nineteen patients successfully underwent blind nasal intubation by BID. The success ratio for first attempt was only 65.0%, while it reached 95.0% for three attempts. Light-guided catheter failed to be inserted for three attempts in only one patient. However, FOB was successfully used for the first attempt by the same anaesthetist. Conclusion Light-guided tracheal intubation by using blind intubation device is a safe and effective method for blind nasal intubation in the patients with temporomandibular joint ankylosis.