Comparison of first-attempt intubation success between Video laryngoscopy and direct laryngoscopy for emergency craniotomy in head injury- a Randomized controlled trial

After obtaining approval from the Post-graduate Research monitoring committee

(human studies), Institute Ethics Committee (IEC) and completing Clinical Trial

Registry India (CTRI) registration, patients satisfying the inclusion and exclusion

criteria will be enrolled in the study after obtaining written informed consent from the

patient (if neurologically intact) or from the next of kin (in case of altered sensorium).

Relevant history- allergies, medications, past medical history, time since last meal and

events leading up to trauma will be noted. A rapid clinical assessment of the patient-

head-to-toe assessment to note for evidence of trauma, systemic examination including

airway examination- will be done and details noted.

Once in operating room, standard American society of anesthesiologist monitors-

pulse oximetry (SpO2), non-invasive blood pressure (NIBP), electrocardiogram

(ECG)- will be attached and baseline parameters noted.

Allocation will be done just before induction of general anaesthesia. Patients will be

randomised into two groups- Group B (BESDATA video laryngoscope) or Group D-

(direct laryngoscopy with conventional macintosh blade). Randomisation will be done

using computer generated block randomisation of varying block sizes. Allocation will

be concealed using serially numbered opaque sealed envelopes.

Laryngoscopy and intubation will be performed following modified RSI technique.

Patients randomised to group D will be intubated using direct laryngoscopy with

macintosh blade and those randomised to group B with BESDATA video

laryngoscope. Laryngoscopy and intubation will be performed by an experienced

anaesthesiologist with at least 20 successful intubations with each device. After

intubation, ET cuff will be inflated, anaesthetic gas circuit will be attached and

mechanical ventilation instituted. Confirmation of successful intubation will be done

by visualisation of end tidal carbon di-oxide (EtCO2) trace on the capnograph and

bilateral chest auscultation.

From the time of induction, haemodynamic parameters- heart rate (HR), systolic blood

pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and

SpO2 will be monitored continuously. All parameters will be recorded every minute

until 5 minutes after successful intubation. HR, SBP, DBP, MAP, and SpO2 will be

documented at baseline (T0), after induction (T1), after intubation (T2), and every

minute for 5 minutes after intubation (T3-T7). EtCO2 will be documented from T2-T7.

An independent observer will record the following parameters using a stopwatch

1. Time to best glottic visualization- time interval between introduction of the

laryngoscope into the oral cavity and optimal visualization of glottis.

2. Time to successful intubation- time interval between introduction of

laryngoscope into the oral cavity and recording of normal EtCO2 waveform.

The following parameters will be assessed and recorded on a standard proforma.

(Appendix 1)

1. Cormack lehane grade of glottic view in all patients. (Appendix 2)

2. Percentage of glottic opening (POGO) score in group B. (Appendix 3)

3. Intubation Difficulty Scale score. (Appendix 4)

4.Ease of insertion – 5 point likert scale. (Appendix 5)

5. Complications- Intubation failure, Oesophageal intubation, Hypoxia,

Hypotension, trauma (mucosal bleeding, dental trauma)

6. Number of laryngoscopy attempts and reasons for multiple attempts- every time

a laryngoscope is introduced into the oral cavity will be considered as ONE

attempt.

● Hypoxia will be defined as a single event of SpO2 less than 90% and will be

managed with bag and mask ventilation and further laryngoscopy attempted

after restoration of baseline SpO2.

● Hypotension will be defined as a decrease in systolic blood pressure by 20%

from baseline or an absolute value of less than 90 mm Hg and will be managed

with fluid and vasopressor (mephenteramine 3 mg iv bolus)

● Inability to intubate within two attempts of laryngoscopy (maximum 60 second

for each attempt) will be defined as failure to intubation.

If intubation failure scenario is encountered, further decision on management will be

left to the attending anaesthesiologist.