Comparison of McGrath Series 5 video laryngoscope with Macintosh laryngoscope: A randomised, controlled trial in patients with normal airways

• Register: ANZCTR
• Last refreshed on: 13 January 2020
• Main ID: ACTRN12614000910606
• Date of registration: 26/08/2014
• Prospective Registration: No
• Primary sponsor: Konya Training and Research Hospital
• Public title: Comparison of McGrath Series 5 video laryngoscope with Macintosh laryngoscope: A randomised, controlled trial in patients with normal airways
• Scientific title: Comparison of McGrath Series 5 video laryngoscope with Macintosh laryngoscope: A randomised, controlled trial in patients with normal airways
• Date of first enrolment: 15/07/2014
• Target sample size: 100
• Recruitment status: Completed
• URL: https://anzctr.org.au/ACTRN12614000910606.aspx
• Study type: Interventional
• Study design: Purpose: Treatment; Allocation: Randomised controlled trial; Masking: Open (masking not used);Assignment: Parallel;Type of endpoint: Efficacy;
• Phase: Not Applicable

Countries of recruitment

Turkey

Contacts

• Name: Prof Sadik OZMEN

• Name: Prof Sadik OZMEN

Key inclusion & exclusion criteria

Inclusion criteria: Scheduled for elective surgery under general anaesthesia requiring tracheal intubation.
Airway difficulty score (ADS) under 8 points.
Amarican Society of Anesthesiology (ASA) physical status I-II.
Over 18 years of age.
Exclusion criteria: Patients with an ADS score above 8 and thyroid-to-chin length of 5 cm or shorter, a Mallampati class 3 or higher, mouth opening less than 3cm, restriction in neck extension or protruding front teeth were predicted to be difficult in intubation and were thus excluded from the study. Also, patients were excluded from the study if they required rapid sequence induction, had a history of previous difficult direct laryngoscopy and had uncontrolled hypertension, ischaemic heart disease, acute or recent stroke or myocardial infarction, cervical spine instability or cervical myelopathy, symptomatic asthma or reactive airway disease and history of gastric reflux.

Age minimum: 18 Years
Age maximum: No limit
Gender: Both males and females

Health Condition(s) or Problem(s) studied

Tracheal intubation to patients with normal airways.;
Tracheal intubation to patients with normal airways.

Anaesthesiology - Anaesthetics

Intervention(s)

We recruited 100 patients of ASA physical status 1-2 who were scheduled for elective surgery under general anaesthesia requiring tracheal intubation.
After obtaining written informed consent, patients were assigned, by using a computer-generated block randomisation, to laryngoscopy with either McGrath videolaryngoscope or the Macintosh laryngoscope. All tracheal intubations with both the Macintosh laryngoscope and McGrath videolaryngoscope were performed by one anesthesiologist who had used both devices more than 50 times clinically.
All patients were expected to fast 6-8 hours before surgery, and no one premedicated. With the patient placed in the supine position, routine monitors (consisting of a pulse oximeter, 3-lead ECG and a non-invasive blood pressure cuff) were applied. Baseline measurements were obtained and 3 min of pre-oxygenation was performed before the induction of general anaesthesia. Standardised anesthetic induction was preformed with 1 mcg/kg fentanyl, 1-2 mg/kg of propofol, and when consciousness was lost, 0.6 mg/kg of rocuronium was injected. After, making sure that all four TOF responses of the Adductor Pollicis disappeared, which ensures sufficient musclular blockade, intubation was then performed. Number 3 or 4 blades was used in all patients. A size 7.0 mm tracheal tube was used to intubate the trachea in female patients, and a size 7.5 mm tube was used for all male patients.
If more than one intubation attempt was required, the patient received bag-and mask ventilation between attempts and various manoeuvres were employed, including external laryngeal pressure, readjustment of the stylet and use of a bougie. Failed intubation was defined as failure after three attempts and a pre-determined alternative airway management

Primary Outcome(s)

The primary outcome was the laryngoscopy view using percentage of glottic opening (POGO) score (0 to 100%, 100 = full view of glottis from anterior commissure to the inter-arytenoid notch, 0 = even inter-arytenoid notch is not seen). [During intubation, 0 to 100%, 100 = full view of glottis from anterior commissure to the inter-arytenoid notch, 0 = even inter-arytenoid notch is not seen.]

Secondary Outcome(s)

Any complications associated with oro-tracheal intubation, such as, , injury to lips, oral mucosal or dentition, oesophageal intubation, or hypoxia (SpO2 < 90%).[During and/or after intubation
]

Haemodynamic changes (blood pressure, heart rate) during intubation. This is assessed by the independent observer, using the patient vital record on the monitor ( blood pressure measured by automatic sphygmomanometer, heart rate measured by ECG)[At baseline, at immediately after intubation and 5 minutes after successful intubation.]

Comparison of the laryngoscopy view using the Cormack and Lehane
grading system (Grade I to IV). This is assessed by the anaesthetist performing the intubation, the view is seen during intubation.[During intubation, when best laryngoscopic view is obtained with the allocated device.
]

Time for successful intubation or until alternative management selected. Alternative management will be decided after failed attempt with the allocated device. Failed attempt is defined as more than three intubation attempts.[During intubation - From insertion of the allocated videolaryngoscope into the participants mouth until end-tidal carbon dioxide (CO2) detected by capnography.]

Number of attempts needed for successful intubation[Recorded during the intubation attempt
]

Secondary ID(s)

nil

Source(s) of Monetary Support

Konya Training and Research Hospital

Ethics review

Status: Approved
Approval date:
Contact:

Necmettin Erbakan University Meram School of Medicine