The Air-Q laryngeal mask airway during anesthesia with controlled ventilation: a clinical trial of efficacy

multiple tools (tubes) were described in literature for securing the patients
airway during anesthesia. in general, an endotracheal tube is used. sometimes,
when the use of an endotracheal tube is not necessary, a laryngeal mask airway
is a propper alternative. laryngeal mask airways are being used frequently,
especially in ambulatory surgery, because their use provides some major
advantages. when using a laryngeal mask airway, there's no need for muscle
relaxants, there's no risk of damaging the vocal cords. furthermore,
laryngoscopical endotracheal intubation provoces a stronger raise in
bloodpressure and heartrate than a laryngeal mask airway does. over the last
decade many types of laryngeal maks airways have been designed, all with their
own strenghts and weaknesses. for example, air leakage is a frequently occuring
event with the classical laryngeal mask, and it's not possible to pass an
endotracheal tube through it. blokkage of the lumen of the laryngeal mask by
the epiglottis does occur, despite bars meant to prevent this from happening.
further development of the laryngeal mask airway has lead to the Air-Q. the
Air-Q is a modification of the classic laryngeal mask airway, with a
differently shaped cuff intended to keep the epiglottis out of the lumen of the
tube. this way the protective bars aren't necessary, so there is nothing
obstructing the lumen. because of this it is possible to pass an endotracheal
tube through the Air-Q. this feature makes the Air-Q an option for intubation
when classic intubation using a laryngoscope failes. intubation using the Air-Q
is likely to be less stimulating than laryngoscope-aided intubation.

we would like to evaluate the efficacy of ventilation an intubation using the
Air-Q. also, we'll evaluate the patients discomforts after extubation.

when a patient wishes to be enrolled in the trial and matches all of the
inclusion criteria and doesn't match any of the exclusioncriteria he or she can
be included.
heartrate and rythm are monitored (3-lead ecg) as well as bloodpressure
(non-invasive) and oxygensaturation.
anesthesia will be induced with propofol 2-3 mg/kg and sufentanil 0.1-0.2
mcg/kg. after disappearence of the cilliary reflex the Air-Q will be inserted.
after three failed attempts the patient will be excluded and will receive care
as usual. the number of seconds passing from touching the lips with the Air-Q
to giving the first effective breath is noted, the number of insertion
attempts, as well as heartrate and bloodpressure directly after insertion. the
cuff will be filled as described by the manufacturer of the Air-Q. standardized
ventilation consists of PCV, 5 cmH2O PEEP, 10-18 cmH2O inspiratory pressure,
frequency 14/min, inspiration-expiration rate 1:2, 40% O2. now we will
determine leakpressure. after turning the flow to 3 L/min of O2, the
expirationvalve will be closed. leakpressure will be determined as the pressure
at which equilibrium is reached. to prevent barotrauma, pressure will be
limited at 40 cmH2O. if indicated, a musclerelaxant will be administered and
the patient will be intubated. again, after three failed attempts the patient
will be excluded and will receive care as usual. now, the patient will be
mechanically ventilated as described above, untill spontaneous respiration
resumes. anesthesia will be maintained with propofol infusion at a rate of 6-12
mg/kg en sufentanil as needed. patients who report severe sore throat (VAS >4)
postoperatively will be called every 48 hours untill the pain is gone.

an Air-Q will be inserted in all patients.
leakpressures are determined.
when indicated, patients will be intubated through the Air-Q.

burden: minimal (3 questions after emergence from anesthesia and every 48 hours
untill disappearence of discomforts)
risk: equal to or less than regular treatment