Can video laryngoscopy make a difference in time to successfull tracheal intubation for caesarian section: the comparison between the C-MAC Video Laryngoscope, the King Vision Video Laryngoscopes and Direct Laryngoscopy

INTERVENTION: After rapid sequence induction using a combination of propofol 2mg/kg i.v., esmeron 1 mg/kg i.v. and Fentanyl 1 mcg/kg i.v. and anaesthetist used one of three intubation devices. Direct laryngoscopy using a curved Macintosh blade is still the standard technique for tracheal intubation during C‐section but the video laryngoscopes can provide an indirect view of the larynx and have been used to manage the difficult airway in the operating room. The King Vision Video laryngoscope (KVL) (King Systems, Indianapolis, Indiana) is a new indirect two‐piece design laryngoscope consisting of a reusable monitor attached to disposable blades. All blades are Macintosh #3 size and compared to a normal Macintosh #3 bladed laryngoscope appear wider and shorter. The blade is inserted into the mouth in the middle, over the centre of the tongue with a single circular movement, while its back surface is maintained against the palate and palatopharyngeal curve. Once the view of glottis is optimized, the tube is passed through the vocal cord into the trachea. We used KVL with a guiding channel. The guiding channel is positioned on the right side of the blade and acts as a conduit holding and directing the tracheal tube through the glottic opening when the vocal cords are visualized. The C‐MAC Video laryngoscope has the Macintosh # 3 or 4 blades incorporating a high‐power light‐emitting diode located in their distal third and extending the viewing angle from the standard 15 degrees to 80 degrees. The VL consists of two parts, a laryngoscope and a monitor, connected via a single cable. A 2‐mm digital camera is sited within the shorter laryngoscope handle and a magnified image displayed on a screen. The C‐MAC displaces soft tissue in a similar fashion to a classic Macintosh laryngoscope, affording room for tracheal tube insertion and consequently less need for intubating adjuncts. CONDITION: Intubation for caesarian section PRIMARY OUTCOME: time to successful tracheal intubation (defined as the interval from the blade insertion to the blade removal from the mouth). ; INCLUSION CRITERIA: Parturients of ASA physical status 1‐3, scheduled for either elective or emergency C‐section SECONDARY OUTCOME: Comparative ease of tracheal tube insertion, as subjectively assessed using a 100 mm Visual Analogue Scale with 0 mm = extremely easy and 100 mm = extremely difficult Need for airway adjuncts such as bougie and ILMA assessed by rewiew of surgical notes. Use of optimisation manoeures such as repositioning of the patient’s head, use of external laryngeal pressure, increase or decrease lifting force of the laryngoscope handle, further advancement or withdrawal of the laryngoscope blade assessed by review of surgical notes. laryngeal view according to Cormac‐Lehane grade ( C/L grade 1, 2 or b, 3,4) rate of successful intubation assessed by review of surgical notes. A failed intubation was defined as an attempt in which the user could not intubate the patient's trachea within two intubating attempts using the same blade, failure to intubate the trachea with the airway device within 60 sec, and patient desaturating at SaO2<92%, will lead to abandonment of the study and the airway will then be managed according to the ASA difficult airway algorithm and guidelines. the number of attempts at intubation assessed by rewiew of surgical notes