[Applications of ultrasound-guided superior laryngeal nerve block and cricothyroid membrane puncture in conscious endotracheal intubation].

Purpose: To explore the clinical value of ultrasound-guided superior laryngeal nerve block and cricothyroid membrane puncture in conscious endotracheal intubation.

Methods: Thirty ASA classⅠorII patients scheduled for selective surgeries were randomly divided into 2 groups, Group U was ultrasound-guided group (n=15), group A was anatomical location group (n=15). Transnasal tracheal intubation was performed in all patients. In patient of group U, thyrohyoid membrane was shown hyperecho by ultrasound and echoless superior laryngeal artery passed across it. Then local anesthetic was injected into inner side of the artery by ultrasound-guided in-plane technology. The same process was conducted in the contralateral side. The cricothyroid membrane was shown as strong echo by ultrasound and the needle was inserted across the membrane by ultrasound-guided in-plane technology. Local anesthetic was injected for surface anesthesia. In patients of group A, superior horn of thyroid cartilage and horn of hyoid cartilage were identified by palpation of the anatomical structure. Traditional bilateral superior laryngeal nerve block was then performed. Thyroid cartilage and cricoid cartilage were marked by palpation of the anatomical structure and local anesthetic was then injected through cricothyroid membrane puncture for tracheal surface anesthesia. All patients experienced rapid anesthesia induction after confirmation of the tracheal intubation. The success rate of cricothyroid membrane puncture, rate of bucking and hemodynamic change around the time of tracheal intubation of each group were recorded. SPSS 20.0 software package was applied for statistical analysis.

Results: Compared with group A, the success rate of cricothyroid membrane puncture in group U was significantly higher (P<0.05) and the rate of bucking was significantly lower (P<0.05).Compared with group A, HR, SBP and DBP in group U at T1,T2 and T5 had no significant difference (P>0.05), but the amount of increase was significantly smaller at T3 and T4 (P<0.05).

Conclusions: Ultrasound-guided superior laryngeal nerve block and cricothyroid membrane puncture in conscious endotracheal intubation is a safe and effective way with more advantages.