Amaniti Ekaterini,  Papakonstantinou Panagiota, Pourzitaki Chrysoula, Papapostolou Evangelia, Nikopoulou Anastasia, Grosomanidis Vasilios
Correlation between preoperative difficult intubation criteria and improvement of laryngoscopic view with the use of c-mac video laryngoscope, compared to conventional laryngoscopy.
Background and Goal of Study: Video laryngoscopies have been shown to improve Cormack-Lehane view. However, the presence of one or more difficult airway criteria increases the possibility of difficult laryngoscopy. Goal of the study was to evaluate whether the presence of one or more prognostic factors of difficult intubation are corelated with greater improvement of Cormack-Lehane view with the use of c-mac video laryngoscope.
Materials and Methods: Patients scheduled to receive general anesthesia and have at least one criterion of difficult intubation, were eligible. Criteria were Mallampati score 3-4, thyromental distance <6cm, cervical movement <90⁰, interincision gap<4cm, presence of buck teeth or micrognathy. Patients were allocated in two groups, based on the number of difficult intubation criteria present (1-2 criteria low risk group LR, 3-4 criteria high risk group, HR).  All patients were anesthetized using a standard regimen and laryngoscopy via conventional laryngoscope was followed. Best view and time to achieve it, were recorded. Afterwards the same anesthetist attempted laryngoscopy through c-mac. The same parametres were recorded.  Comparisons between time to best views and best views achieved via conventional vs cmac laryngoscope were made for both groups (Wilkoxon test). Statistical significance was set at p<0.05.
Results and Discussion: A total of 30 patients were studied (LR=19, HR=11). Time to best view was significantly shorter for c-mac, compared to conventional laryngoscopy, only for HR group (p=0.000). Regarding laryngoscopic image, LR and HR groups showed significantly better laryngoscopic views, compared to conventional laryngoscopy (p<0.001 for both LR and HR). 
Conclusion(s): Cmac leads to better laryngoscopic views, no matter how many criteria of difficult intubation are present. In HR group, cmac also improves the time to best view.


08 / Correlation between preoperative difficult intubation criteria and improvement of laryngoscopic view with the use of video laryngoscope, compared to conventional laryngoscopy.