title: Nasotracheal intubation using the Blind Intubation Device in anaesthetised adults with Mallampati class 3:  a comparison with the Macintosh laryngoscope.
abstract: BACKGROUND
  We hypothesised that the Blind Intubation Device (BID) would be effective for nasotracheal intubation (NTI) in anaesthetised adults with Mallampati class 3. We also hypothesised that BID may cause less haemodynamic changes due to the avoidance of direct stimulation induced by the Macintosh blade.
  
  
  OBJECTIVE
  The purpose of the study was to compare the effectiveness of the BID with the Macintosh laryngoscope for NTI in anaesthetised adults with Mallampati class 3.
  
  
  METHODS
  A prospective randomised controlled study.
  
  
  METHODS
  Operation unit in a University Hospital in Shanghai. Period of the study was from September to November 2010.
  
  
  METHODS
  Mallampati class 3 adults requiring NTI for elective oral and maxillofacial surgery were randomly assigned to a BID group (n = 25) or a Macintosh laryngoscope group (ML group) (n = 25).
  
  
  METHODS
  After anaesthesia induction, patients were intubated by a single anaesthesiologist experienced in using both devices.
  
  
  METHODS
  The mean arterial pressure (MAP) and heart rate (HR) were recorded at specific time points. NTI duration and success rate was compared. Epistaxis-associated and NTI-associated postoperative complications were assessed.
  
  
  RESULTS
  Compared with baseline values, there was a significant increase in MAP in both the BID and ML groups which persisted significantly longer in the ML group. The BID group showed a significantly attenuated MAP value within 30-60 s. The difference between the maximum MAP and the post-induction value was significantly greater in the ML group than in the BID group (64.4 ± 16.1 vs. 45.9 ± 16.1 mmHg, P = 0.0003). Compared with baseline values, there was a significant increase in HR in both groups which persisted longer in the ML group. There was a significantly higher first attempt success rate in the BID group compared with the ML group (100 vs. 76%, respectively, P = 0.022). The NTI duration was 36 s [interquartile range (IQR) 32-40] in the BID group and 33 s (IQR 25.5-41.5) in the ML group. Epistaxis during NTI was less frequent and less severe in the BID group (P = 0.031).
  
  
  CONCLUSIONS
  In adults with Mallampati class 3, NTI using the BID caused an attenuated haemodynamic response and showed a higher success rate on the first attempt without increasing adverse events. The BID is an effective alternative to the Macintosh laryngoscope for NTI in anaesthetised adults with Mallampati class 3.
  
  
  BACKGROUND
  Clinicaltrials.gov identifier: NCT 01170455.
authors: Department of Anaesthesiology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors: Yu
authors: Y
authors: Sun
authors: Jin-Xing
authors: JX
authors: Liu
authors: Ye-Sen
authors: YS
authors: Zhu
authors: Hui
authors: H
authors: Xu
authors: Yan
authors: Y
authors: Huang
authors: Hong
authors: H
authors: Jiang
mesh_terms: D000328:Adult; D000768:Anesthesia, General; D001794:Blood Pressure; D016009:Chi-Square Distribution; D002681:China; D004844:Epistaxis / Q000209:etiology; D004867:Equipment Design; D005260:Female; D006339:Heart Rate; D006785:Hospitals, University; D006801:Humans; D007442:Intubation, Intratracheal / Q000009:adverse effects / Q000295:instrumentation*; D020704:Laryngoscopes; D008297:Male; D008875:Middle Aged; D009055:Mouth / Q000033:anatomy & histology; D009960:Oropharynx / Q000033:anatomy & histology; D011446:Prospective Studies; D013997:Time Factors; D014059:Tongue / Q000033:anatomy & histology