Comparison of double lumen tube insertion using the McGrath MAC versus direct laryngoscopy in adult patients with a limited glottis view: A prospective interventional study

BACKGROUND AND AIMS: Passage of double-lumen tubes (DLT) can be challenging in patients with limited glottis view. This study aims to determine the usefulness of McGrath® MAC videolaryngoscope (VL) in cases with limited glottis view on direct laryngoscopy with Macintosh blade. MATERIAL AND METHODS: After study approval and registration of trial, consent was sought from all adult patients planned for elective DLT insertion for lung isolation during the course of general anesthesia. Patients not consenting, less than 18 years, with anticipated difficult mask ventilation or need for rapid sequence induction were excluded. Following routine anesthetic induction, laryngoscopy was attempted by an experienced anesthesiologist using Macintosh scope. If the view obtained was Cormack and Lehane (CL) view IIB and above or the attempt at intubation using DLT failed despite a CL I/IIA view, the patient was included in the trial. The laryngoscope was removed and after ensuring adequate oxygenation and depth of anesthesia, intubation was attempted using McGrath® MAC VL. The percentage of glottis opening (POGO) score was noted for both the scopes. RESULTS: DLT insertion was attempted in 76 patients in the study period. Eight patients were included in the trial on account of limited glottis view/failure with Macintosh scope. Insertion of DLT with McGrath MAC was tried only in six patients, in two patients, the VL was not available for use. The mean (standard deviation) POGO score with Macintosh scope was 9 (±20), which significantly improved with the use of VL to 71 (±24), P = 0.01. CONCLUSION: McGrath MAC is helpful in inserting DLT in patients with limited glottis view with Macintosh scope.