بازنگري طبقه بندي راه هوايي به روش LEHANE و CORMACK با توجه ويژه بر يافته هاي گريد II

A revision of the Cormack and Lehane laryngoscopic grading system with special consideration to grade II laryngoscopic view

Background: The major responsibility of an anesthesiologist is to provide adequate respiration for the patient. The most vital element in providing functional respirati on is the airway. No anesthetic is safe unless diligent efforts are devoted to maintaining an intact functional airway. Difficult intubation had been class ified into four grades, according to the view obtainable at laryngoscopy by Cormack and Lehane in 1984. This grading system has been in use to evaluate and manage those patients with difficult airway by anesthesiologists. In clinical state, grades III and IV are quite rare, so the need for a modified Cormac k and Lehane grading system was felt. The use of a modified Cormack-Lehane scoring system of laryng oscopi c views during direct laryngo scopy, was previous ly examined in the Western population. Koh and his co-workers had examined this modified Cormack and Lehane grading system in Asian population in a study in Singapore General Hospital. The aim of this study was to investigate this scoring system in Iranian patients. Methods: In a cross sectional study, a modified version of the Cormack and Lehane grading system was evaluated in 300 patients requiring tracheal intubation. In the modified system, grade 11 (only part of tbe glottis is visible) was divided into lla (part of the cords is visible) and Ilb (only the aryrenoids or the very posterior origin of the cords are visible). Difficult intubation was defined as requiring more tban one laryngoscopy or the use of special equipmcnts. Results: Sixty eight patients (22.7%) were scored as grade Ila and 32 (7.7%) as grade lib. The prevalence of difficult intubation in grade l lb was significantly higher than patients in group na (47.8% vs, 2.9% respectively, Fisherʹs exact test, p= 0.00I) Conclusion: The modified grading system provides more information than the original Cormack and Lehane system.