Videolaringoskopi Uygulanan Hastalarda Başarısızlığı Etkileyen Parametrelerin Belirlenmesi

Abstract

Videolaryngoscopy (VL) is one of the most frequently used methods in managing patients with difficult airway. It has been observed that the success of endotracheal intubation increases with VL, in patients who are predicted to have a difficult airway with preoperative bed-side airway evaluation tests. In these tests, some parameters were determined for difficult direct laryngoscopy. The risk factors for predicting VL failure are not yet known exactly. In this study, it was aimed to determine the parameters that affect VL failure in clinical practice. After the approval of the ethics committee, the patients who were undergoing surgery under general anaesthesia were followed between February 2018 and March 2020 in this prospective observational study. Intubations attempted using VL were included to the study. Anthropometric information of the patient such as age, body weight, height, gender; difficult airway predictive values such as mouth opening, thyromental distance, modified Mallampati scoring, neck range of motion, upper lip bite test; the history of difficult intubation and the operation performed were recorded. The reason for using videolaryngoscopy, the blade type, whether the intubation was successful or not, the alternative method used if videolaryngoscopy is unsuccessful, and the experience of the intubator were recorded. Also, the effect of all these parameters on the success of videoryngoscopy was evaluated. VL was performed in 1159 patients between February 2018 and March 2020. Endotracheal intubation was successful with VL in 98.5% of patients, and 1.5% (n:17) of patients could not be intubated with VL. The ratio of VL failure was higher in pediatric patients (p=0,033). Statistically significant difference in mouth opening, modified Mallampati scoring, thyromental distance, neck range of motion, upper lip bite test, history of difficult intubation and concomittant syndromic diseases was found between patient groups which VL was successful and unsuccessful. The most significant predictors of failure were mouth opening below 2 cm (odds ratio:14,49), limitation of neck movement (odds ratio:6,25) and upper lip bite test class ≥ 2 (odds ratio:5,84). It was observed that as the Cormack-Lehane (CL) grades, the number of intubation attempts and the experience of last operator increased, the rate of videolaryngoscopy failure also increased. It has been found that VL improved the glottic appearance of patients classified as CL 3. and 4. degrees by direct laryngoscopy to CL 1. and 2. degree. Among the blades used, the Storz C-MAC D blade had the highest success rate. Among the pediatric blade variants, the Miller blade was observed to be more unsuccessful than the pediatric Storz C-MAC D blade. Lower body weight and shorter thyromental distance were the statistically significant parameters that differ in pediatric patients who could not be intubates successfully using VL. The parameters that cause videolaryngoscopy failure are not clearly defined in the literatüre. In this study, it was found that mouth opening <2 cm, limited neck movements, and upper lip bite test class ≥2 were the strongest factors predicting difficult videolaryngoscopy. In patients with a predicted difficult airway, especially in the presence of these three findings, alternative airway techniques and the use of awake methods should be considered, considering that videolaryngoscopy may also fail.