Anesthetic management of laser airway surgery

Feasibility of standard mechanical ventilation with low FiO2 and small endotracheal tubes during laser microlaryngeal surgery

BACKGROUND

No technique can be considered as a gold standard for ventilation during direct laser CO2 laryngeal microsurgery. We evaluated the feasibility of standard ventilation with laser-safe endotracheal tubes (ETTs) and inspired O2 fraction (FiO2) = 0.21 during direct microlaryngoscopy.

METHODS

During total intravenous anesthesia, standard mechanical normoventilation was set with FiO2 = 0.21 and 50 mm Hg peak inspiratory pressure limit. If SpO2 was <90% for >2 minutes, FiO2 was increased to 0.3; after 4 minutes it was increased to 0.4; after another 4 minutes, positive end-expiratory pressure (PEEP) could be set at 5 cm H2O; and after another 4 minutes, surgery was stopped if SpO2 remained <90%.

RESULTS

We studied 111 consecutive direct microlaryngoscopies on different patients. Four patients (3.6%) suffered minor intraoperative desaturation. Barotrauma was not observed, PEEP was never applied, and surgery was never stopped. Body mass index was independently predictive of the occurrence of intraoperative desaturation.

CONCLUSIONS

Standard mechanical ventilation with FiO2 = 0.21 through laser-safe ETTs is feasible during direct microlaryngoscopy.

Juvenile laryngeal papillomatosis: scary anaesthetic!

We describe three children ages 20 to 33 months who presented for surgical resection of their laryngeal papillomata. Their anaesthetic management revealed the severity of obstruction which these children presented and the obstacles that faced the anaesthesiologist trying to secure the airway and provide adequate ventilation. The airway obstruction had both a fixed and a dynamic component to it. This was evidenced by the ability of the children to maintain ventilation when spontaneously breathing. But, they exhibited total obstruction when ventilation was attempted via mask using positive pressure. It is possible to encounter obstruction to ventilation after the trachea has been intubated because of papillomata that were 'shaved off,' filling the tracheal tube lumen.