Clinical Evaluation of Laryngeal Tube and Laryngeal Mask Airway for Cardiac Arrest Treatment in Emergency Ambulances in Singapore

Endotracheal intubation (ETI) is considered the gold standard of airway management as it a definitive airway providing ventilation and prevention of aspiration in a patient unable to protect his airway. However, it can only be used by skilled, experienced personnel and can be difficult in the pre-hospital setting. It may also result in unrecognized oesophageal intubation. Currently ETI is not recommended for Singapore Civil Defence Force (SCDF) ambulances by MHA (Medical Advisory Committee) and local paramedics were not trained to this level of skill and competency. Furthermore, there has been reduced emphasis on early tracheal intubation unless achieved by highly skilled individuals to minimise interruption to chest compressions according to the 2010 resuscitation guidelines.

In view of the above reasons, ETI is not recommended by the Ministry of Home Affair's Medical Advisory Committee (MAC). Instead, the disposable laryngeal mask airway (LMA) has been used as the primary airway by paramedics in SCDF's Emergency Ambulance Service (EAS) in the management of both medical and traumatic cardiac arrest patients and is approved by the MAC for use in both adults and children.

However there can still be complications with the LMA such as incomplete seal and partial airway obstruction from mask misplacement or kinking. In addition, SCDF's self-reported success rate of LMA is only 50-87% .Hence there was a need to explore other alternatives to the LMA. The American Heart Association (AHA) recommends advanced airway adjuncts such as the Laryngeal Tube (LT) and Oesophageal-tracheal tube (Combitube) for alternative airway strategies. Other devices include the pharyngeaotracheal lumen airway and the oesophageal obdurator airway - oesophageal gastric tube airway (EOA-EGTA).

Investigators have chosen the LT as an alternative adjunct because it has a higher insertion success rate than LMA. It also has low complication such as regurgitation, vomiting and dislodgement and comes in sizes to accommodate both paediatric and adult. Method of use is quite simple as it can be inserted blindly into the oropharynx and pushed in until resistance is felt or device is fully inserted as denoted by the markings on the device.

Our long term objective is to improve existing EAS's cardiac arrest protocol and placement success rate and to lower complications and adverse events rates in out of hospital cardiac arrest. The result of the study will be reviewed by SCDF's Medical Advisory Committee (MAC). The results can also determine the choice of rescue airways used in the hospitals eg operating theatres, emergency departments, endoscopy rooms.