Using a King Vision video laryngoscope, time to glottic view, best Cormack-Lehane grade, time to intubation, time to first ventilation has been recorded.

Best Cormack-Lehane score (as declared by the laryngoscopist) obtained with both laryngoscopes is recorded.

Cormack-Lehane score is graded according to the following criteria (1 is best, and 4 is worst):

1. full view of glottis (difficult intubation unlikely)
2. partial view of glottis (~5% risk of difficult intubation)
3. partial view of epiglottis, none of glottis seen (~90% risk of difficult intubation)
4. neither glottis nor epiglottis seen (difficult intubation very likely)

Any complication related to the laryngoscopy and intubation, such as cut, bleeding, damage to the teeth, laryngospasm, bronchospasm, desaturation below 90%, is recorded.

Mallampati class is used to indirectly assess the distance between the base of the tongue and the roof of the mouth, to predict how difficult an intubation will be.

"American Society of Anesthesiologists score" is a widely used grading system for preoperative health of the surgical patients.

It is based on five classes (I to V):

I-a completely healthy fit patient.

II-patient has mild systemic disease.

III-patient has severe systemic disease that is not incapacitating.

IV-patient has incapacitating disease that is a constant threat to life.

V-a moribund patient, not expected to live 24 hour w/out surgery. E-designates emergency surgery (added after roman literal like "IIE").

Successful endotracheal intubation is defined as the endotracheal cuff passing the patient's vocal cords. Time to intubation with each laryngoscope is recorded.

Glottic view time (as defined when the laryngoscopist declared the best Cormack-Lehane score) with each laryngoscope is recorded.

Cormack-Lehane score is obtained by directly assessing the distance between the base of the tongue and the roof of the mouth to predict how difficult an intubation will be.

It consists of 4 grades:

1. full view of glottis (difficult intubation unlikely)
2. partial view of glottis (~5% risk of difficult intubation)
3. partial view of epiglottis, none of glottis seen (~90% risk of difficult intubation)
4. neither glottis nor epiglottis seen (difficult intubation very likely)

Best Cormack-Lehane score (as declared by the laryngoscopist) obtained with both laryngoscopes is recorded.

Cormack-Lehane score is graded according to the following criteria (1 is best, and 4 is worst):

1. full view of glottis (difficult intubation unlikely)
2. partial view of glottis (~5% risk of difficult intubation)
3. partial view of epiglottis, none of glottis seen (~90% risk of difficult intubation)
4. neither glottis nor epiglottis seen (difficult intubation very likely)

Any complication related to the laryngoscopy and intubation, such as cut, bleeding, damage to the teeth, laryngospasm, bronchospasm, desaturation below 90%, is recorded.

These patients had been intubated with a Macintosh laryngoscope first, and then with a King Vision video laryngoscope. Airway complications related to the laryngoscopy and intubation (cuts, bleeding, damage to the teeth, laryngospasm, bronchospasm, desaturation below 90%) had been recorded.

Fall of saturation of peripheral oxygen below 90%

Any kind of dental damage, such as enamel fracture or avulsion during laryngoscopy, were recorded.

Any case of painful or swollen throat were questioned at the entrance to and exit from the postanesthetic care unit by the anesthesia technician, and in the surgical ward by the nurse.