June 2012, Volume 26, Issue 3, pp 362-368
Effect of jaw thrust and cricoid pressure maneuvers on glottic visualization during GlideScope videolaryngoscopy
During performance of direct laryngoscopy in the difficult-to-visualize airway, several maneuvers have the potential to impact glottic visualization, including jaw thrust and cricoid pressure. The effect of these maneuvers on glottic visualization during videolaryngoscopy has not been studied. We evaluated the effect of jaw thrust and cricoid pressure maneuvers on both visualization of the glottis and the area of glottic opening visible during GlideScope-aided videolaryngoscopy.
One hundred patients were enrolled in this study. After induction of general anesthesia, videolaryngoscopy was followed by jaw thrust and cricoid pressure maneuvers performed in random order. Laryngeal anatomy was recorded continuously and was saved as digital images following the initial laryngoscopy and after each maneuver. Glottis grade [modified Cormack and Lehane (C&L)] was recorded, as was the total glottic area.
There was improvement in glottis grade when utilizing jaw thrust maneuver in comparison to GlideScope videolaryngoscopy alone (31% improved, 4% worsened; P <;;;;;;; 0.001). There was no difference in glottis grade when using the cricoid pressure maneuver in comparison with videolaryngoscopy alone (39% improved, 20% worsened; P = 0.19). Glottic opening area, however, was greater when utilizing the jaw thrust maneuver in comparison with videolaryngoscopy alone (P <;;;;;;; 0.001), but smaller when utilizing the cricoid pressure maneuver in comparison with videolaryngoscopy alone (P <;;;;;;; 0.001).
The jaw thrust maneuver was superior to videolaryngoscopy alone in improving the modified C&L grade and the visualized glottic area; however, no significant improvement was noted with cricoid pressure. We therefore recommend the use of jaw thrust as a first-line maneuver to aid in glottic visualization and tracheal intubation during GlideScope videolaryngoscopy.
Anaesth Intensive Care. 2012 Jan;40(1):128-30.
Improving the C-MAC video laryngoscopic view when applying cricoid pressure by allowing access of assistant to the video screen.
Department of Anaesthesia and Acute Pain Management, Peninsula Health, Frankston, Victoria, Australia. firstname.lastname@example.org
Cricoid pressure, as part of rapid sequence induction, may on occasion worsen laryngoscopic views and intubating conditions. We investigated whether allowing the assistant applying cricoid pressure to view the video laryngoscope screen would improve the laryngoscopic views compared to when they were blinded to the video screen. Laryngoscopy using the C-MAC video laryngoscope was performed in 51 patients undergoing elective general anaesthesia. Photographs were recorded sequentially under the following conditions: A) cricoid pressure by an assistant unable to see the video monitor, and B) cricoid pressure optimised by an assistant able to see the video monitor. These photographs were analysed offline by assessors blinded to whether the photo was obtained with blinded or non-blinded cricoid pressure application. Subjectively, 41% of views were improved when the assistant applying cricoid pressure was able to see the C-MAC screen, compared to those unable to see the screen. The view was unchanged in 45%, but initially worsened in 14%. These findings suggest that assistants applying cricoid pressure when a C-MAC is used should have access to the video image, but must also respond to requests for change from the person performing the intubation.
Minh’s clinical pearl : If you are having difficulty in intubation/laryngeal view, with DL, VL or SGA placement or blind intubation via an iLMA of whatever type. Get trusted assistant to apply a decent jaw thrust.
It will improve whatever airway technique you are trying!