Purpose: External laryngeal manipulation (ELM) is used to get better laryngeal view during direct laryngoscopy. This study was designed to test the hypothesis that ELM done by the intubating anesthetist (laryngoscopist) offers the best laryngeal view for tracheal intubation.
Materials and method: A total of 160 patients underwent different surgical procedures were included in this study. Percentage of glottic opening (POGO) score and Cormack and Lehane scale were used as outcome measures for comparison between different laryngoscopic views. Four views were described; basic laryngoscopic view and then views after ELM done by the assistant, by the laryngoscopist and finally by the assistant after the guidance from the laryngoscopist respectively. The last three views compared with the basic laryngoscopic view.
Results: ELM done by the laryngoscopist or by the assistant after guidance from the laryngoscopist showed significant improvement of Cormack grades and POGO scores compared with basic laryngoscopic view. Number of patients with Cormack grade1 increased from 39 after direct laryngoscopy to 97 and 96 patients (P < 0.001 by Fisher's exact test), after ELM done by the laryngoscopist and that done by the assistant after guidance from the anesthetist respectively. Furthermore, the number of patients with POGO scores of 100% increased from 39 after direct laryngoscopy to 78 and 61 (P < 0.01) patients after ELM done by the laryngoscopist and that done by the assistant after guidance from the anesthetist respectively.
Conclusion: It appeared from this study that ELM done by the anesthetist makes the best laryngeal view for tracheal intubation.
Keywords: Cormack and Lehane scale; external laryngeal manipulation; glottic opening score; laryngeal view.