Published in BMC Anesthesiol. 2014;14(72)
Authors: Hung-Te Hsu et al
Background The use of a video-assisted laryngoscope (VL) has been shown to reduce the time to achieve intubation with a double-lumen endobronchial tube (DLT). As the blade of the VL is curved differently to a standard laryngoscope, the DLT must be angled into a hockey stick shape to fit properly. We conducted a study to establish which direction of angulation was best to facilitate correct positioning of the DLT when using a VL.
Methods We enrolled patients scheduled for thoracic surgery who required intubation with a DLT. They were prospectively randomized into one of two groups: those intubated with a DLT angled to conceal the tracheal orifice (the tracheal orifice-covered, TOC) group or the tracheal orifice-exposed (TOE) group. The composite primary outcome measures were time taken to intubate and the frequency of first-time success. The time taken to intubate was divided into: T1, the time from mouth opening to visualization of the vocal cords with the VL; and T2, the time taken to advance the DLT through the cords until its tip lay within the trachea and three carbon dioxide waveforms had been detected by capnography. The hemodynamic responses to intubation and intubation-related adverse events were also recorded.
Results Sixty-six patients completed the study, with 33 in each group. Total intubation time was significantly shorter in the TOC group (mean 30.6 ± standard deviation 2.7 seconds versus 38.7 ± 3.3 seconds, p <0.0001). T2 was also significantly shorter in the TOC group than the TOE group (27.2 ± 2.5 seconds versus34.9 ± 3.0 seconds, p <0.0001). The severity of hoarseness on the first postoperative day and sore throat on the fourth postoperative day were significantly lower in the TOC group than the TOE group (p = 0.02 and <0.0001, respectively). The hemodynamic responses to intubation were broadly similar between the groups.
Conclusion When placing a left-sided DLT using a VL, angling the bronchial lumen to a hockey stick shape that conceals the tracheal lumen saves time and ameliorates the severity of post-intubation complications.