Intraocular pressure changes: the McGrath video laryngoscope vs the Macintosh laryngoscope; a randomized trial.

ABSTRACT

STUDY OBJECTIVE: To determine the effects of the McGrath Series 5 video laryngoscope on intraocular pressure (IOP) during laryngoscopy. DESIGN: Prospective, randomized, double blind. SETTING: Operating room. PATIENTS Eighty adult patients of American Society of Anesthesiologist physical status 1 scheduled for nonophthalmic elective surgery under general anesthesia. INTERVENTIONS: The endotracheal intubation was provided using McGrath series 5 video laryngoscope in MG group (n=40) or Macintosh laryngoscope in M group (n=40). MEASUREMENTS The IOP of the right and left eyes was measured before and after the laryngoscopic process. MAIN RESULTS: The mean arterial blood pressure values just before laryngoscopy and intubation and after intubation were 77.38±6.18 and 97.38±12.77 in the McGrath video laryngoscope group and 75.85±7.88 and 99.12±14.30 in the Macintosh laryngoscope group, respectively. The IOP values of the left eye after intubation and at the 5th and the 10th minutes in the Macintosh laryngoscope group were found to be significantly higher than those in the McGrath video laryngoscope group (P=.019, P=.019, and P=.007, respectively). In addition, the IOP values of the right eye were found to be higher after intubation and at the 5th and the 10th minutes in the Macintosh laryngoscope group, compared to the McGrath video laryngoscope group (P=.009, P=.021, and P=.011, respectively). The mean IOP values for the left eye just before laryngoscopy and intubation and after intubation were 10.65±2.52 and 15.57±3.62 in the McGrath video laryngoscope group, and for the right eye, they were 10.60±1.64 and 17.17±2.38 in the Macintosh laryngoscope group, respectively. CONCLUSION: The McGrath Series 5 video laryngoscope may provide a lower IOP level compared to the Macintosh laryngoscope in an otherwise healthy, young patient population.