Nasotracheal Intubation Using A Modified Flexible Lightwand-Guided Technique For Oromaxillofacial Surgical Patients

ObejectiveThe purpose of this study was to investigate the feasibility, efficiency and safety of themodified flexible lightwand guided nasotracheal intubation compared with directlaryngoscopy in oromaxillofacial surgical patients.Methods50patients [American society of anesthesiology （ASA）Ⅰorâ…¡] for elective oral andmaxillofacial surgery under general anesthesia that required nasotracheal intubation wereenrolled in this study. As a self-control study, patients were allocated to intubation byexperienced hands in the use of both devices. Then their body mass index （BMI）, mouthopening （MO）, thyromental distance （TMD）, upper lip bite test （ULBT）, Mallampati class（MC）, were evaluated and recorded before intubation. General anaesthesia was inducedwith midazolam0.04⁰.06mg·kg^-1, fentanyl4⁶μg·kg^-1, propofol1.5²mg·kg^-1andvecuronium0.1mg·kg^-1.3minutes later, all patients undergoing nasotracheal intubationwere assisted with direct laryngoscope （DL） at first attempt to determine Cormacklaryngoscopy grade and aided with modified flexible lightwand （ML） device at the secondattempt by experienced staff anaesthesiologist. Systolic blood pressure （SBP）, diastolicblood pressure （DBP） and heart rate （HR） were recorded, and the change from “beforeintubation” to “immediately after intubation”（△P） in each variable was calculated.Endotracheal intubation time （EIT）, success rate at one attempt, ease of intubation asmeasured on a100mm visual analog scale （VAS,0=easy,100=difficult）, usage of Magill forceps and adverse events or complications were recorded too.ResultsWe found that using the ML resulted in shorter endotracheal intubation time （median（interquartile range, IQR）7.5s （6-9.5） vs25s （17.75-30））, easier intubation （VAS,median（IQR）10（5-15） vs30（20-50））, and an increased rate of successful insertion at thefirst attempt （98%vs70%）, all P<0.001. In comparing baseline hemodynamic responses,no significant differences in SBP, DBP values was noted in the two groups （P>0.05） exceptHR in the group DL （P<0.05）. However, there is no difference in HR changes between thetwo techniques （P>0.05）. Magill forceps were not used in the ML group, but were used64%in the DL group （P<0.001）. Furthermore, neither of the patients had dental injury, orlip or nasal mucosa damage during the study （P>0.05）. The Cormack and Lehaneclassification of the patients correlated well with the Mallampati score （r=0.55, P<0.001）.For laryngoscopic intubation, the time was longer and the intubation was more difficult forpatients with a higher Mallampti score. However, there was no obvious relation between theBMI and intubation time, ease of intubation. In contrast, there were no significantcorrelations between the EIT and any of the airway parameters for modified flexiblelightwand.ConclusionThe modified flexible lightwand guided nasotracheal intubation provides less intubationtime, easier intubation and an increased rate of successful insertion at the first attemptwithout an increase in adverse effects than laryngoscopic intubation in patients undergoingoromaxillofacial surgery. It is a rapid, effective and safe nasotracheal intubation device.