OBJECTIVETo compare the hemodynamic responses to nasotracheal intubation with Glide Scope video-laryngoscope (GSVL), Macintosh direct laryngoscope (MDLS), and fiberoptic bronchoscope (FOB).

METHODSSixty patients, with American Society of Anesthesiologists (ASA) physical status I - II, aged 18- 50 years, and scheduled for elective plastic surgery under general anesthesia requiring nasotracheal intubation, were randomly allocated equally to GSVL group, MDLS group, and FOB group. After the routine anesthesia induction, nasotracheal intubation was performed with the GSVL, MDLS, and FOB, respectively. Noninvasive blood pressure (BP) and heart rate (HR) were recorded before (baseline values) and after anesthesia induction (postinduction values), at intubation, and subsequently at an interval of every 1 minute for a total of five minutes. The maximum and minimum values of BP and HR during the observation period were also noted. The rate pressure product (RPP) at each measuring time point was calculated. The areas under effect-time curve (AUE) of hemodynamics were calculated by time as X-axis and changes of BP and HR during the observation as Y-axis.

RESULTSAll the three groups were similar in the demographic data and intubation time. After anesthesia induction, BP and RPP in all the three groups decreased significantly compared to baseline values (P < 0. 05), while HR had no significant change. After nasotracheal intubation, BP, HR, and RPP in all three groups were significantly higher than the postinduction values (P < 0.05). In the FOB group, BP, HR, and RPP at intubation significantly increased when compared with the baseline values (P < 0.05). In the MDLS group, HR at intubation, and maximum values of diastolic blood pressure (DBP), mean arterial pressure (MAP), HR, and RPP during the observation were significantly higher than the baseline values (P < 0.05). In the GSVL group, all hemodynamic parameters at intubation and after intubation were not significantly different from the baseline values. BP, HR, and RPP at intubation, and the incidences of HR more than 100 bpm during the observation were significantly higher in the FOB group than in the other two groups (P < 0.05). BP was not significantly different during the observation between the MDLS and GSVL groups, but HR and RPP at intubation and after intubation as well as AUE(HR) were significantly higher in the MDLS group than in the GSVL group (P < 0.05). AUE(HR) and AUE(SBP) were significantly lower in the GSVL group than in the FOB group (P < 0.05).

CONCLUSIONThe hemodynamic responses to nasotracheal intubation are most severe with FOB, followed by MDLS, and then GSVL.