Airway management of morbidly obese patients presents a real challenge for anaesthesiologists. These patients have excessive fat deposition externally over neck, breast and thorax and internally in oropharyngeal cavity and abdomen. This excessive fatty tissue can impede airway patency and negotiation of endotracheal tube through glottis. Various techniques have been utilized for successful management of airway in these patients. Every technique has its own merit and demerits. Till now awake fibre optic intubation has been gold standard for management of difficult airway. Since last few years various video laryngoscopes have been introduced in clinical practice and these are also found to be very promising in difficult airway management especially in obese patients. Here, we will describe the advantages and disadvantages of awake video laryngoscope aided intubation compared with awake fiberoptic intubation and conventional laryngoscopy in airway management of morbidly obese
Videolaryngoscopy(VL) was invented in 2001 by John Pacey, since then various types of video laryngoscopes are available for use. Video laryngoscope provides high quality images that are magnified on video monitor for easier visualization. It has anatomically shaped blade with an extra curve which avoids excessive compression of oropharyngeal tissue to achieve straight line of site during laryngoscopy.  Thus video laryngoscope avoids the need for significant lifting force to visualize the glottis which decreases the hemodynamic changes associated with laryngoscopy, hence it is more suitable for awake intubation compared to conventional laryngoscopy. It provides enlarged image of airway structure compared to narrow airway view seen during conventional laryngoscopy. During external laryngeal manipulation, intubating person and assistant both can coordinate movements by looking at the images on video monitor. VL improves the Comarck Lehane score compared to conventional laryngoscopy as it provides the view of laryngeal inlet independent of line of sight, while DL depends on formation of line of sight between operator and larynx which needs careful head positioning and consistent anatomy. Therefore VL has been associated with higher tracheal intubation success rate than standard DL in patients with predicted difficult airway.
Fiberoptic intubation (FOI) has been gold standard for difficult airway management but it also has certain limitations like requirement of more time, experience and blind tube passage through glottis whereas VL needs less experience and time, less affected by secretions, blood and provides real time view of airway and tube placement. So VL can be an useful alternative to FOI in difficult intubation scenario.
Video laryngoscopes  carry certain disadvantages also. It lacks the versatility of FOS. At least 25 mm of mouth opening is required for the insertion and manipulation of a VL, so in patients with restricted mouth opening, FOI is better option. In the presence of abnormal upper airway anatomy, FOI may favour over a video laryngoscope. When performing video laryngoscopy, the operator’s visual attention may be diverted from the mouth to the screen while introducing the laryngoscope and endotracheal tube which can lead to surrounding soft tissue or endotracheal tube cuff damage. Some VLs have only one fixed-size blade for use in difficult airway, hence not suitable for use in children and in some adults.
To conclude airway management in morbidly obese patients can be challenging.  When carefully planned it is possible to identify those patients who present a much higher risk for difficult ventilation and intubation. Awake video-laryngoscopy has caused a paradigm shift in airway management of these morbidly obese patients. Traditional teaching has focussed on training on flexible fiberoptic bronchoscopy but the airways of morbidly obese patients may not be well suited for this particular teaching , the many video laryngoscopes currently available may provide better alternative.
References

1. Moore AR, Schricker T, Court O. Awake videolaryngoscopy-assisted tracheal intubation of the morbidly obese.  Anaesthesia. 2012 Mar;67(3):232-5.
2. Abdellatif AA, Ali MA. GlideScope videolaryngoscope versus flexible fiberoptic bronchoscope for awake intubation of morbidly obese patient with predicted difficult intubation. Middle East J Anaesthesiol. 2014 Feb;22(4):385-92.
3. Marrel J, Blanc C, Frascarolo P, Magnusson L. Videolaryngoscopy improves intubation condition in morbidly obese patients. Eur J Anaesthesiol. 2007 ;24(12):1045-9.
4. Curtis R. Awake videolaryngoscopy-assisted tracheal intubation in the morbidly obese. Anaesthesia. 2012 Jul;67 (7):796-7.