Evaluation of success rate of classic Laryngeal mask insertion on the first try with three different technique: the classic methods, lateral and rotational in obese patients with BMI more than 30

1- Objectives: The aim of this study was to find the best way laryngeal mask insertion, in people with a body mass index over 30, which could lead to less complications in patients. 2- Design: In this study insertion of laryngeal mask in patients undergoing general anesthesia are, to classical methods, will be compared with lateral and rotational. The best method with the least side effects is indicated in patients with a body mass index above 30 is used. 3- Setting and conduct: After ethical approval by the Tabriz University of Medical Sciences faculty of medicine , 135 patients with the BMI more than 30 candidates for orthopedic surgeries with anesthesia will be studied in this prospective clinical trial, and randomly divided into three groups using the software will be made. Induction of the anesthesia will be similar in all patients including : pre-oxygenation by 100% oxygen , Midazolam 0.03 mg/kg , Fentanyl 1-2 µg/kg , Propofol 2-3 mg/kg .An anesthesiologist which is expert in inserting LMA in 20-30 seconds will insert the LMA with three techniques standards , lateral and rotational . the patients will be monitored by NIBP, HR, ECG, Pulse Oximetery and ETCO₂. 4- Participants outcome including major eligibility criteria; Inclusion criteria: The obese patients with BMI more than 30 ; Candidate for anesthesia with laryngeal mask insertion. Exclusion criteria: Body mass index less than 30; During the operation more than 2 hours; Other than the supine position surgery; In head and neck surgery; Patients at risk for aspiration; Patients known to have airway problems; Multiple attempts to put the laryngeal mask. 5- Intervention: laryngeal mask to classical methods, Insertion of laryngeal mask to classical methods, lateral and rotational in patients with a body mass index over 30 by the anesthesiologist. 6- Main (measures) variables: The data to be recorded will be: LMA insertion time, number of insertion tries, leak around LMA and grading it by ventilation with the pressure of 20 cmH₂O as: Grade one: no leak; Grade two: feeling of leak; Grade three: feeling of leak with sound with appropriate ventilation; Grade four: feeling of leak with sound with inappropriate ventilation; Grade five: complete airway obstruction. Assessment of appropriate ventilation using: ETCO₂ , good chest movements and continuous oxygenation. complications like blood on the mask of LMA , sore throat as none , mild , moderate and severe and any change in patient voice will be recorded.

The costs of patient surgery and additional costs for projects not required. Through Medical insurance will be provided.