Background and Goal of Study: 
Cardiac surgery has shown higher difficult intubation (DI) rates compared to other kind of surgeries[1][2]. Older age, male gender, morbid obesity and dental problems have been associated with these findings[1][3].
The aim of this study is to describe the prevalence of DI in cardiac procedures in our centre, as well as to analyze wether parameters as age, body mass index (BMI) and type of surgery (valve replacement (VR) or coronary artery bypass (CAB)) could be predictors of DI in our population.

Materials and Methods: 
We reviewed retrospectively a total of 590 patients undergoing cardiac surgery; 333 VR, 199 CAB, and 58 were other procedures. Age, height, weight, type of surgery, Cormack-Lehane Grade (CLG) and intubation technique were assessed. Patients with CLG III and IV were considered DI. Obesity was defined as BMI >30. The univariate analysis for non-continuos variables were described using Chi-square test and factors associated with DI using multivariate logistic regression models.

Results and Discussion: 
Amongst a total of 590 patients , 374 were men (63%) and 216 (36%) women. Median age was 68,6 ±11,6 years, weight 75 ± 15 kg, height 1,64± 0,09 m and BMI 27,55 ± 4,8. We reported 31% normal BMI, 41% overweight, 25,6% obesity and 1,7% morbid obesity. The overall incidence of DI was 15% (87/590). 
The prevalence of DI showed no difference between obesity patients (17,4%) as compared to non obesity (14%, p= 0,307). Similar results comparing DI in VR surgeries (15,1%) and CAB surgeries (15,4%, p=0,576). Otherwise there was higher prevalence of DI in men (17,4%) versus women (10,7% p=0,028). 
The analysis demonstrated that the independent predictor associated with DI in our population would be the male sex (OR 1,954 (95% CI 1,153-3,31; p=0,011), neither age, kind of cardiac surgery, or obesity. 

Conclusion(s): 
Patients submitted for cardiac surgery in our center had a higher prevalence of DI compared to  the rates reported in other surgical procedures according to the literature. Although male gender was a variable associated with DI, there were no significant differences that may suggest that age, obesity and type of surgery can be independent risk factors for DI.

References (optional):
1. Indian J Anaesth. 2017 Aug;61(8):629-635. doi: 10.4103/ija.IJA_283_17. Are cardiac surgical patients at increased risk of difficult intubation? Borde DP1, Futane SS1 et col.
2. J Cardiothorac Vasc Anesth. 2015 Dec;29(6):1537-43. doi: 10.1053/j.jvca.2015.04.027. Epub 2015 May 5. Increased Rate of Poor Laryngoscopic Views in Patients Scheduled for Cardiac Surgery Versus Patients Scheduled for General Surgery: A Propensity Score-Based Analysis of 21,561 Cases. Heinrich S1, Ackermann A2 et col.
3. J Cardiothorac Vasc Anesth. 2003 Jun;17(3):321-4. Difficult laryngoscopy: incidence and predictors in patients undergoing coronary artery bypass surgery versus general surgery patients. Ezri T1, Weisenberg M, Khazin V, Zabeeda D, Sasson L, Shachner A, Medalion B.


10 / Prevalence of difficult intubation in cardiac surgery: relation to obesity, age, gender and type of surgery