Comparison of the effects of the McGRATH MAC, C-MAC, and Macintosh laryngoscopes on the intraocular pressures of non-ophthalmic patients: A prospective, randomised, clinical trial

Abstract

IntroductionIn this prospective, randomised study, we compared the effects of the Macintosh, McGRATH MAC, and C-MAC laryngoscopes on intraocular pressure (IOP) and haemodynamics of non-ophthalmic patients during endotracheal intubation. MethodsOne hundred and twenty adult patients undergoing non-ophthalmic surgeries performed in the supine position under general anaesthesia requiring orotracheal intubation were included in this study. The patients were separated randomly and prospectively into 3 groups: Macintosh group (n = 40), McGRATH MAC group (n = 40), and C-MAC group (n = 40). Mean arterial pressure (MAP), heart rate (HR) and IOP of left and right eye were measured at specified times. ResultsThere were no significant differences with regard to patients characteristics. After intubation, the HR increased significantly in the Macintosh group when compared to the other groups (p = 0.001) and the MAP increased significantly in the Macintosh group when compared to the McGRATH MAC group (p = 0.001) and the C-MAC group (p < 0.001). The IOP values increased in the Macintosh group when compared to the McGRATH MAC group (p < 0.001) and the C-MAC group (p < 0.001) after intubation. Additionally, there was a significant difference between the McGRATH MAC group and C-MAC group in the IOP values of the eyes after intubation (p < 0.001). According to the evaluation within the groups, there were significant differences in all of the groups at all times when compared with the baseline values (p < 0.001). ConclusionsIn this study, we concluded that the C-MAC VL may be preferable when compared to the Macintosh and McGRATH MAC laryngoscopes for use in ophthalmic patients in whom a rise in the IOP is undesirable.