Comparison Between Rigid Video Assisted Laryngoscopy vs Flexible Laryngoscopy in Anticipated Difficult Intubation

This is a randomized control study where adult patients had been divided randomly into two equal groups using video laryngoscope in group (V) and flexible intubating laryngoscope in group (F)

Routine pre-operative assessment including history taking, clinical examination, and laboratory tests. Patients were admitted to the operating room with a small 20G IV cannula after applying inclusion \& exclusion criteria and airway assessment by applying El Ganzuri multivariate risk index for difficult intubation which include assessment of the following : inter-incisor gap, Mallampati classification, head \&neck movement, buck teeth prognathism, thyromental distance, body weight and history of difficult intubation.

Operating room was prepared using :

Difficult airway cart that includes different size oral airways, endotracheal tubes, different sizes face masks \& laryngeal airway masks Suction apparatus to be ready for use Video laryngoscopy The flexible intubating laryngoscopy with the tube mounted over the fiberscope before the procedure.

Standard monitoring devices were applied including ECG, non invasive blood pressure. pulse oximetry and capnography after intubation Patients were then pre-oxygenated via face mask for three minutes and using 0.01 mic/kg atropine then general anesthesia is induced using fentanyl 1-2 mic/kg followed by propofol 2 mg/kg and esmeron 0.5 mg/kg.

The patient is mechanically ventilated using face mask until full relaxation is established after 3-5 minutes. The intubation is done using video laryngoscope in group (v) or using flexible intubating laryngoscopy in group (f) In the first group (v) The video laryngoscope was introduced with the patient appropriately positioned, the operator used the left hand to introduce the video laryngoscope into the midline of the Oropharynx and gently advances until the blade tip pass the posterior portion of the tongue. Using video visualization, the ETT was then advanced on a smooth curve through the glottis and intubation proceeds. Viewing the entire insertion step on the video screen allows the operator to quickly become facile with the motion of gently rotating or angling the tube using the right hand to redirect as necessary.

In the second group(f) patients positioned supine with the operator standing at the head of the bed. Simple chin lift and jaw thrust may improve the view through the flexible laryngoscopy and also help to prevent airway obstruction. The endotracheal tube should be lubricant to facilitate its subsequent advancement into the trachea. Once the endotracheal tube is in place, the scope is removed, and the patient is ventilated. Flexible intubating laryngoscopy is often performed with the operator looking through the eyepiece. However, connecting the flexible laryngoscopy to a monitor is often advantageous.

After collecting demographic data of the patient (age, sex, body mass index \& ASA) The following parameters will be measured :

Intubation time, Hemodynamic parameters, success rate and number of attempts \& incidence of complications.

Eligibility Criteria:
Inclusion Criteria:

1. El-Ganzouri score: 2, 3, 4 (Table 1)
2. American Society of Anesthesiology (ASA) I, II, III
3. Elective surgeries

Exclusion Criteria:

1. Refusal of participation
2. Patients who need a surgical airway (e.g. patients with highly obstructing laryngeal lesions such as cancer tongue, larynx\& maxilla).
3. Patients with laryngeal trauma, especially in those with suspected cricotracheal separation.
4. Patients with craniofacial trauma.