Variant of the Technique for Laryngeal Microsurgery in Cases of Difficult Laryngoscopy

Magnesium sulfate administration in difficult laryngoscopy: An effective and safe method

PURPOSE

Difficult laryngeal exposure during laryngeal microsurgery and laser surgery is a major concern for otolaryngologists. This study evaluated the efficacy and safety of magnesium sulfate administration in difficult laryngeal exposure patients.

STUDY DESIGN

Quasi-experimental design.

MATERIALS AND METHODS

Forty adult patients scheduled for laryngeal microsurgery with difficult laryngeal exposure according to Cormack-Lehane (CL) classification were included. Magnesium sulfate 50% (20-30 mg/kg) was administered as a bolus injection. Laryngeal exposure and hemodynamic stability were evaluated before and after the intervention.

RESULTS

CL grading was shown a statistically significant improvement after magnesium sulfate administration. There are no clinically significant changes in the mean arterial pressure, heart rate, and oxygen saturation levels in the patients who received magnesium sulfate for better laryngeal exposure.

CONCLUSION

Magnesium sulfate is an effective and safe drug for better viewing in difficult laryngeal exposure patients.

Prediction of difficulty in direct laryngoscopy

To establish easily measurable and reproducible preoperative parameters predicting difficult laryngeal exposure in direct laryngoscopy. A prospective study including 71 patients who underwent transoral microsurgery for benign or malignant lesions of the larynx was performed in our department from January 2021 to November 2021. Physical assessment included the Mallampati score, weight, height, body mass index and measurements of seven parameters in the cervical region. Eleven parameters were measured on the cervical radiography film. Among our patients, 19 were included in the difficult laryngeal exposure (DLE) group. High Mallampati and Cormack scores were significantly associated with DLE (p = 0.005 and p < 0.0001). Limited mouth opening, direct thyromental distance (DTMD) < 67 mm in neutral position, DTMD < 82 mm and sternomental distance < 157 mm at full head extension were statistically related to DLE. For radiological assessment, the effective length of the maxilla and the atlanto-occipital distance were related to DLE. Using stepwise logistic regression, only the effective length of the maxilla and atlanto-occipital distance were selected as independent predictors for DLE (p: 0.015 and 0.001). Preoperative prediction of DLE is useful for both surgeons and patients. The length of the maxilla and the atlanto-occipital distance were found to be independent risk factors for DLE. This highlights the effect of overgrowth of the maxilla, protrusion of the upper teeth and limited extension of the cervical spine as the major risk factors for difficult laryngeal exposure.

Utility of videolaryngoscopy for diagnostic and therapeutic interventions in head and neck surgery

BACKGROUND

Videolaryngoscopy is commonly used by anesthesiologists to manage difficult airways. Recently otolaryngologists have reported use in select procedures; to date there is limited evaluation in head and neck surgery.

MATERIALS AND METHODS

Patients who underwent direct laryngoscopy (DL) with use of GlideScope videolaryngoscopy (GVL) were retrospectively identified from a tertiary care Veterans Affairs hospital. GVL was used to assist or replace traditional laryngoscopes for diagnostic and therapeutic procedures.

RESULTS

Nineteen patients (48-83 years old) underwent 21 procedures. Difficult endotracheal intubation was reported in 53% of patients. GVL replaced traditional DL in 76% of cases, assisted evaluation prior to traditional DL in 10%, and rescued failed traditional DL in 14%. No complications occurred. Three indications for GVL were identified.

DISCUSSION

GVL was safe in our experience and provides unique benefits in selected scenarios in head and neck surgery. Otolaryngologists can consider videolaryngoscopy as a complement to traditional DL.