Intubation through an I-gel laryngeal mask airway in prone position

Prone position ventilation is indicated in patients suffering from severe ARDS,
patients undergoing spine surgery and in out-of-hospital trauma scenes. When
accidental extubation occurs, there is a primary urge for ventilation since a
delay in ventilation causes hypoxia with possible fatal outcome.
One method to regain the ability for ventilation is to turn the patient to the
supine position and perform handbag ventilation, although this is time
consuming and sometimes impossible (during spine surgery). Another method is to
insert a LMA in prone position, and high success rate for ventilation are
achieved. Some patients, however, need to be intubated, because of the high
ventilation pressures, unfasted state or leakage of tidal volume. Inserting an
endotracheal tube through the LMA is the simplest method. However, success
rates are unknown and moreover, manoeuvres to increase this success rate have
not been investigated previously.

Some LMA*s, such as the FastTrach and the iLMA, are especially designed for
intubating through the LMA and high success rates are achieved. However,
successful insertion in prone position is limited with these devices. Since the
I-gel has a high success rate for ventilation in prone position, this device
could be the LMA of choice. However, intubating through the I-gel has lower
success rates in supine position. In prone position, this has not investigated
previously. Therefore, a study with intubation through the I-gel is necessary
to provide recommendations regarding this device.

One method to increase the intubation success rate is to use the VivaSight
Single Lumen tube (VVSL), which has a camera at the tip of tube. This allows to
alter the direction of the tube. The main disadvantage of this tube are the
required resources, such as the videoscreen, the availability of the tube and
the high costs compared to the simple Parker-tube. Therefore, this method is
likely to be unavailable in urgent situations. In this study, the view obtained
by the VVSL can be used to provide recommendations for manoeuvring the Parker
endotracheal tube.

The primary objective is to quantify the overall success rate of intubation in
prone position through an I-gel LMA.

The secondary outcomes are time for insertion of the I-gel LMA, time for
intubation, glottic view obtained by the VSSL, manoeuvres necessary for
intubation, leakage of tidal volume by ventilation through the I-gel LMA and
the percentage of patients with post-operative dysphonia and a sore throat on
the recovery ward.

The study design is a prospective observational study.

The burden of this study is that participants have to endure extra pharyngeal
manoeuvres (up to three) which gives a slightly higher risk of a temporary sore
throat or temporary dysphonia. This manoeuvre happens under general anaesthesia.
There are no other burdens (e.g. questionnaires, additional site visits or
examinations).
There are no risks, since standard clinical safety measures are imbedded in
this study.