Laryngeal mask airway vs endotracheal tube to facilitate bedside percutaneous tracheostomy in critically ill patients: a prospective comparative study.

BACKGROUND: Inadvertent puncture of endotracheal tube (ETT) cuff and accidental tracheal extubation are the potential life threatening complications during percutaneous dilatational tracheostomy (PDT). As an alternative to ETT, the laryngeal mask airway (LMA) has been used sporadically but no large study is available on its use.

AIMS: To study the use of LMA during PDT on controlled ventilation in critically sick patients and compare its advantages and disadvantages in relation to ETT.

SETTINGS AND DESIGN: This prospective, randomised, comparative study was conducted in intensive care unit of a super-speciality, tertiary care hospital.

METHODS AND MATERIAL: The bedside PDT was performed in 60 critically ill patients using Ciaglia's kit. The patients received controlled ventilation of lungs either through ETT or LMA. The feasibility of the procedure and complications were compared in two groups.

RESULTS: In LMA group, 33% of patients suffered with potentially catastrophic complications, e.g., loss of airway, inadequate ventilation of lungs leading to significant hypoxia, gastric distension and regurgitation. In ETT group there were 6.6% incidence of ETT impalement, 6.6% cuff puncture and 3.3% accidental tracheal extubation. Despite the technical difficulties (cuff puncture, etc.) the ETT technique was basically safe, whereas despite of the theoretical advantages the LMA technique rendered some patients at considerable risks of hypoxia and gastric regurgitation-aspiration.

CONCLUSION: The LMA does not provide safe patent airway to facilitate bedside PDT in critically sick population on controlled ventilation. The ETT is safer for controlled ventilation and should be continued to secure the airway for this purpose until a better alternative is available.