1.      Departments involved:Anaesthesiology

2.      Summary of the proposed study  ( 250 words)

Airway management is the prime responsibility of the anaesthesiologist. Video laryngoscopes are now a part of airway management armentarium. King vision laryngoscope is one of the most cost effective video laryngoscope available. The learning curve for successful use of video laryngoscope is short compared to direct laryngoscopy. In this study we will be comparing video laryngoscope with direct laryngoscope when used by airway novices.

The study design will be a prospective, randomized, controlled study which will be conducted in Ramaiah Medical College Advanced learning center simulation lab.  To evaluate the difference in efficacy between direct laryngoscopy(DL) and video laryngoscope(VL), we will randomly assign 106 medical students to either of 2 intubation groups of 53 each.

GROUP DL - DIRECT LARYNGOSCOPE

GROUPVL – VIDEO LARYNGOSCOPE

All participants will be briefed for 5-minute instructions on DL and VL that included an introduction to the equipment and demonstrated both a misplacement of the ETT in the esophagus and the correct placement in the trachea. Then, the students will oriented on the mannequin so that they could visualize the correct anatomic landmarks and the ideal insertion path of the ETT.  The trial will end when the student either the participant successfully passes the ETT into the trachea or the 300 second time limit reached.

The participants then will crossover and perform laryngoscopy and intubation using the other device. The same parameters will be measured.To assess time for successful endotracheal intubation. We will also record the esophageal intubations, first attempt intubations and excessive pressure on the maxillary incisor teeth. We also determine the overall endotracheal intubation success rate of the two groups.  The comparison of ease of use between the devices will be scored.

3. Any work already done– A pilot study has already been done.

4.      Justification or Need for the study :

The purpose of this study was to determine whether video laryngoscopy (VL) provides any advantage over direct laryngoscopy (DL) in first-attempt intubations by inexperienced medical students in simulation. Our hypothesis is by using VL the time taken for successful first attempt endotracheal intubation is considerably faster. Also it might also provide good intubating conditions by reducing the incidence of esophageal intubation (EI), excess application of pressure on the maxillary incisor teeth (EMP). There are no studies on the use of VL in comparison with DL in airway novices

5.      Aims &Objectives:

1.      Compare the video laryngoscope with the traditional Macintosh laryngoscope in  identifying  the time for successful endotracheal intubation.

2.      Secondary outcome measures includes the incidence of esophageal intubation (EI), excess application of pressure on the maxillary incisor teeth (EMP), and first-time success rate.

3.      Ease of use  in using direct larygoscopy versus video laryngoscopy .

6.      Hypotheses (if applicable):

7.      Review of literature : (within 500 words)

1. HannesPrescher et. al.⁽¹⁾  Conducted a study  to determine whether video laryngoscopy provides any advantage over direct laryngoscopy in first-attempt intubations. This was a controlled, randomized study of 120 medical students. Students were randomly assigned to either of 2 intubation groups, which used  DL (n=64) VL (n=56) with the Karl Storz C-MAC video laryngoscope. Each student attempted 1 endotracheal intubation on a Laerdal Airway Management Trainer. The primary outcome measure was the time for successful endotracheal intubation. Secondary outcome measures included the incidence of esophageal intubation (EI), excess application of pressure on the maxillary incisor teeth (EMP), and first-time success rate. Mean time for endotracheal intubation was significantly faster in the VL group than in the DL group (101 ± 83 seconds vs. 180 ± 102.5 seconds; PË‚0.001). In the VL group, 3.6% of the students committed an EI versus 56.3% in the DL group (PË‚0.001). No significant difference was found in the incidence of EMP: 51.8% in the VL group versus 57.8% in the DL group (P=0.508). For medical students with little or no endotracheal intubation experience, VL facilitates success and decreases the number of EIs, at least in a simulated environment

2. J. McElwain et.al.⁽²⁾ conducted  a study  to compare the C-MAC with Macintosh, Glidescope  and Airtraq  laryngoscopes in easy and simulated difficult laryngoscopy. Thirty-one experienced anaesthetists performed tracheal intubation in an easy and difficult laryngoscopy scenario. The duration of intubation attempts, success rates, number of intubation attempts and of optimisationmanoeuvres, the severity of dental compression, and difficulty of device use were recorded. In easy laryngoscopy, the duration of tracheal intubation attempts were similar with the C-MAC, Macintosh and Airtraq laryngoscopes; the Glidescope performed less well. The C-MAC and Airtraq provided the best glottic views, but the C-MAC was rated as the easiest device to use. In difficult laryngo- scopy the C-MAC demonstrated the shortest tracheal intubation times. The Airtraq provided the best glottic view, with the Macintosh providing the worst view. The C-MAC was the easiest device to use.

3. Frank Herbstreit et. al.⁽³⁾ Conducted a  prospective assessement in medical students  intubation skills acquired by intubation attempts in adult anesthetized patients during a 60-hour clinical course  in a randomized fashion, either a conventional Macintosh blade laryngoscope or a videolaryngoscope.  Skills were measured before and after the course in a standardized fashion (METI Emergency Care Simulator) using a conventional laryngoscope. All 1-semester medical students (n  93) were enrolled.  The students’ performance did not significantly differ between groups before the course. After the course, students trained with the videolaryngoscope had an intubation success rate on a manikin 19% higher (95% CI 1.1%–35.3%; P < 0.001) and intubated 11 seconds faster (95% CI 4–18) when compared with those trained using a conventional laryngoscope. The incidence of difficult (manikin) laryngoscopy was less frequent in the group trained with the videolaryngoscope (8% vs 34%; P = 0.005).

4. K. J. Howard-Quijano et.al.⁽⁴⁾  conducted a study to determine if video-assisted laryngoscopy improves the effectiveness of tracheal intubation training. In this prospective, randomized, crossover study, 37 novices with<6 prior intubation attempts were randomized into two groups, video-assisted followed by traditional instruction (Group V/T) and traditional instruction followed by video-assisted instruction (Group T/V). Novices performed intubations on three patients, switched groups, and performed three more intubations. During video-assisted instruction, novices were successful at 69% of their intubation attempts whereas those trained during the non-video-assisted portion were successful in 55% of their attempts (P<0.04). Oesophageal intubations occurred in 3% of video-assisted intubation attempts and in 17% of traditional attempts (P<0.01).They concluded the study by stating  improved rate of successful intubation and the decreased rate of oesophageal intubation support the use of video laryngoscopy for tracheal intubation training.

    V.            Materials  and Methods

The study design will be a prospectiverandomized study of 106 students who are doing internship. This study will be conducted in Ramaiah Medical College Advanced learning center simulation lab.  To evaluate the difference in efficacy between DL and VL, we will randomly assign 106 medical students to either of 2 intubation groups of 53 each.

GROUP-1- DL  - DIRECT LARYNGOSCOPE

 GROUP-2- VL – VIDEO LARYNGOSCOPE

INCLUSION CRITERIA

(1)   All interns posted in anaesthesiology.

EXCLUSION CRITRERIA

(1)   Interns who have performed >5 or more laryngoscopy /intubation.

All participants will be briefed for 5-minute instructions on DL and VL that included an introduction to the equipment and demonstrated both a misplacement of the ETT in the esophagus and the correct placement in the trachea. Then, the students will oriented on the mannequin so that they could visualize the correct anatomic landmarks and the ideal insertion path of the ETT.  The orientation will be given by anaesthetist with extensive clinical intubation experience.  Their will not be any trial runs by the participants. After the training, each of the students will attempt one endotracheal intubation by using conventional direct laryngoscope using Macintosh size 3 blade or video laryngoscope on the mannequin. They will be timed from initiation of hand placement on the laryngoscope to successful intubation with a 7.0 ETT, as evidenced by visible lung excursion. If students perform an esophageal intubation, as indicated by inflation of the stomach pouch, this will be counted as 1 EI and students will be prompted to start again. We will record the number of EI during the study time. A maximum time limit of 300 seconds (5 minutes) will be set for all students. The trial will end when the student either the participant successfully passes the ETT into the trachea or the 300 second time limit reached.

Failure to achieve endotracheal intubation by that point will be defined as an “unsuccessful” intubation trial.  The mannequin gives an audible indication to signal tooth damage when excessive pressure on the upper incisors is applied during laryngoscopy and this will be recorded. The study will have a research assistant help prepare the ETT and the stylet, inflate the ETT cuff after intubation and begin mechanical ventilation with an Ambu bag valve mask. This is to ensure that the intubation time reflects only the participant’s ability to obtain proper visualization and to pass the ETT, the two pivotal steps of the intubation procedure . The research assistant will be a simulation technician who has specifically trained to perform these tasks and in no other way interfered with the performance of the study.

The participants then will crossover and perform laryngoscopy and intubation using the other device. The same parameters will be measured.

The time for successful endotracheal intubation will be noted. We will also record the esophageal intubations, first attempt intubations and excessive pressure on the maxillary incisor teeth. We also determine the overall endotracheal intubation success rate of the two groups.  The comparison of ease of use between the devices will be scored.

SAMPLE SIZE

To calculate the required number of participants to perform the study we considered  the previous study conducted by Prescher et al. who observed that time taken for intubation with DL scopy was found to be 118 ± 67 seconds; whereas with video laryngoscope using C-MAC it  was found to be 81.9 ± 57.1 seconds. In the present study we are expecting the similar results with a power of 80 % , confidence level of 95 % and considering 30 seconds difference as  clinical significant  in one tilt test between the two groups. The study requires a total of 106 subjects with 53 subjects in each group. The participants will be allotted into groups by computer generated random number table.

STATISTICAL METHODS

Descriptive statistics of time taken for successful endotracheal intubation will be analysed and summarized in terms of mean with SD, independent‘t’ test would be used to compare time between the two groups.

 VI.            Ethical considerations and methods to address issues: NO

VII.            Implications of the study

In near future video laryngoscope might replace direct laryngoscopes as the learning curve is short.

VIII.            Budget and proposed funding source: Self funded

 IX.            References

1.      Hannes Preacher, David E. Biffar, Laura E. Meinke, John E. Jarred, Aubrey J. Brooks, Allan J. Hamilton. Video-guided Versus Direct Laryngoscopy: Considerations For Using Simulation To Teach Inexperienced Medical Students. The Society for Modeling and Simulation International, Simulation Series. Vol. 46; 10.ed: 2014; 253-258.

2.      J. McElwain, M.A. Malik, B.H. Harte, N.M. Flynn, and J.G. Laffey.Comparison of the C-MAC  videolaryngoscope with the Macintosh, Glidescope, and Airtraq laryngoscopes in easy and difficult laryngoscopy scenarios in manikins. Anaesthesia 2010 ; 65: 483–489

3.      Frank Herbstreit, Philipp Fassbender, HelgeHaberl, Clemens Kehren, and Ju¨rgen Peters .Learning Endotracheal Intubation Using a Novel Videolaryngoscope Improves Intubation Skills of Medical Students  . Anesth Analg 2011; 113: 586–90

4.      K. J. Howard-Quijano , Y. M. Huang , R. Matevosian , M. B. Kaplan and R. H. Steadman1 . Video-assisted instruction improves the success rate for tracheal intubation by novices. Br J Anaesth 2008; 101: 568–72

    X.            Enclosures: Case record form, informed consent, Questionnaire(if any)

• Study proforma
• Informed consent form

STUDY PROFORMA

NAME:

AGE:                           SEX:                           Roll no

1.      EXPERIENCE IN AIRWAY MANAGEMENT:                   YES/NO

If yes    

A.  Seen laryngoscopy and intubation                            YES/NO

If yes number

B.     Assisted laryngoscopy and intubation                      YES/NO

If yes number

2.      PERFORMED ANY AIRWAY MANAGEMENT: YES/NO

(If yes number done)

1.      Laryngoscopy       1          2          3          4          5         

2.      LMA insertion      1          2          3          4          5         

AIRWAY MANAGEMENT: DIRECT LARYNGOSCOPY/ VIDEO LARYNGOSCOPY

Ease of use of video laryngoscope  in comparison to mactintosh blade (please tick)

(    ) Difficult

(    ) Easy

(    ) Same