Comparative Evaluation of C-Mac, Pentax Video Laryngoscopes, and Macintosh Laryngoscope in Endotracheal Intubation in Intensive Care Unit Wearing a Face Shield.

The endotracheal intubation will be performed with anesthesiologist working in ICU previously trained and experienced in videolaryngoscopy and will be classified according to their skill into 3 groups: Junior (1 year up to 3 year) senior, (3 year up to 8 years) and consultant (more than 8 years) experience. All the laryngoscopist groups will equally attend in performing intubation of the studied group. After the patient consent, the allocation will be opened and preparation for intubation will start. All the intubations will be performed with the presence of two laryngoscopist: one of them at least senior or consultant. After confirmation of well working standard monitoring (ECG, blood pressure, Spo2 and End-tidal CO2) and preoxygenation with 100% oxygen, induction with propofol (1-2 mg/kg) and rocuronium (0.9 mg/kg) will be achieved by an assistant.

While wearing head-fitted face shield, the anesthetist will perform intubation with suitable sized laryngoscopy blade and endotracheal tube. Successful placement of ETT will be confirmed by both auscaltation and capnography (normal appearing waveform over four or more breathing cycles). During endotracheal intubation, anesthesiologists will be permitted to make ergonomic adjustments, such as altering the bed height, position of the patient head and utilize external laryngeal manipulations, equipment adjustment and use of stylet based on their personal preferences. After three failed attempts of intubation, alternative techniques will be used and subsequently, they will not be included in the analysis. Alternative techniques such as gum elastic bougie, laryngeal mask airway (LMA), Cricothyrotomy set will be ready to any unexpected difficult airway. An intubation attempt is defined as introduction of laryngoscope and its subsequent removal with or without endotracheal tube (ETT) placement. Correct placement of ETT in first attempt by an individual laryngoscopist will be defined as first-pass successful intubation.