Benefits of Intramuscular Glycopyrrolate Premedication on Intubation With Rigid-videostylet (OptiScope® PM 201, KoMAC Co., Ltd, Seoul, Republic of Korea)

Recently, the newer forms of intubating devices combining video technologies were introduced. The fiberoptic stylets are useful instrumentations especially for difficult airways and limited neck mobilizations.The OptiScope® is a semi-rigid videostylet designed for endotracheal intubation. While using the device, visualization of the airway might be obscured by the secretions during its insertion. The deterioration of the view leads to intubation failure, resulting in multiple intubation attempts, longer intubating time and desaturation.Therefore, while using the Opticoscope®, proper antisialagogic preparation will be helpful.

Total 78 patients scheduled for general anesthesia aged 20-65 years and Anesthesiologists physical status (ASA) class 1 or 2 will be included. The obese patients (BMI>30) and expected difficult intubation will be excluded. The sample size was estimated based on the preliminary study. With a type Ⅰ error estimate(α) of 0.05 at 80% power, we estimated that 30 patients in each group, or 60 in total, were needed. Considering the drop-out rate of 30%, the total sample size were 78 in total. The patients will be randomly allocated to the glycopyrrolate group(G) and the control group(C). The group-G will received intramuscular glycopyrrolate 0.005mg/kg injection 1 hour before the surgery. For the group-C glycopyrrolate will not be administered. Intubation will be conducted with the OptiScope®. While intubating, the degree of the secretion will be evaluated through the OptiScope® and graded excellent, good, poor and unacceptable according to the dryness and the visualization of the vocal cord. When the vocal cord was seen without secretions, it was stated 'Excellent'. 'Good' was graded when secretions existed without the need for suctioning to visualize the vocal cord. When there were secretions and needed suctioning to clear the view, the subjects were rated 'Poor'. When intubation was failed due to poor visualization of the vocal cord despite the suctioning of the secretion, it was graded 'Unacceptable'. If the intubation is not available within 1 minute, the intubation will be done with the laryngoscope. The time to intubate will be checked by the assist anesthesiologist. The definition of the 'intubation time' is the time between the introduction of the OptiScope® into the mouth and the confirmation of the proper intubation with capnographic wave.The baseline vital signs including systolic blood pressure, mean arterial pressure, diastolic blood pressure and heart rate will be measured before the intubation and 1,3 and 5 minutes after the intubation.

The collected data will be compared with the independent t-test or Mann-Whitney-Wilcoxon test for the continuous variables. Χ2 test and Fisher's exact test will be performed for the categorical variables. Significant level will be set at 0.05.