MedPath

Effects of Intubation on Intra-ocular Pressure and Optic Nerve Sheath Diameter

Not Applicable
Completed
Conditions
Intraocular Pressure
Interventions
Procedure: McGrath videolaryngoscopy
Procedure: C-MAC videolaryngoscopy
Device: Direct laryngoscopy
Registration Number
NCT05763056
Lead Sponsor
Inonu University
Brief Summary

Brief Summary:

In this study, the investigators aimed to compare the effects of different types of endotracheal instruments (Machintosh laryngoscope, McGrath videoingoscope and C-Mac videoryngoscope) on intraocular pressure, optic nerve diameter and hemodynamic parameters.

Detailed Description

Detailed Description:

Laryngoscopy and endotracheal intubation cause increased intracranial pressure due to hypoxia, hypercapnia, straining, or coughing. It may be an indirect result of increased arterial and venous pressure, as well as a direct effect of intubation.

With the emergence of neuroimaging techniques and new diagnostic tools, various methods have been developed that can replace invasive methods, which are the gold standard in intraocular pressure measurement. However, invasive methods such as intraventricular and intraparenchymal catheter systems have some disadvantages and are associated with significant risks in terms of infection, bleeding, and time lost until follow-up.

The intraorbital subarachnoid space surrounding the optic nerve shows the same pressure variation as the intracranial subarachnoid space, and any increase in intracranial pressure is also seen in the orbital subarachnoid space. With the increase in intracranial pressure, the optic nerve, optic nerve sheath diameter, and subarachnoid space enlarge. There are many studies reporting that optic nerve sheath diameter can be evaluated using ultrasonography. Although there is no clear cut-off value for optic nerve sheath diameter, previous studies have found that an optic nerve sheath diameter of 5.0 mm and above may indicate an increase in intracranial pressure.

Previous studies have determined that the distribution of intraocular pressure in the adult population varies between 11 mmHg and 21 mmHg, and the mean intraocular pressure is 16.5 mmHg. It is well known that the sympathoadrenergic response caused by laryngoscopy and tracheal intubation significantly increases intraocular pressure (at least 10-20 mmHg). In addition, intravenous pressure and intraocular pressure increase due to cough, airway obstruction, succinylcholine use, hypoxia and hypercapnia during intubation.

In this study, the investigators aimed to compare the effects of different types of endotracheal instruments (Machintosh laryngoscope, McGrath videoingoscope and C-Mac videoringoscope) on intraocular pressure, optic nerve sheath diameter and hemodynamic parameters.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
120
Inclusion Criteria
  • Non-ophthalmic surgery
  • Mallampati I or II classifications
  • American Society of Anesthesiologists (ASA) I-II
Exclusion Criteria
  • Glaucoma,
  • Diabetes mellitus,
  • Cardiovascular diseases,
  • Pulmonary diseases,
  • ASA 3 and 4
  • Body Mass Index (BMI) greater than 30
  • Eye surgery
  • Difficult intubation (Mallampati score of 3 or 4, thyromental distance of less than 6 cm and a maximum mouth opening of less than 3 cm)
  • Intraocular pressure value more than 20 mmHg
  • More than two intubation attempts
  • A risk of regurgitation patients
  • History of obstetric surgery
  • Allergies to propofol, fentanyl or rocuronium

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Direct laryngoscopyDirect laryngoscopyMacintosh laryngoscopy is still one of the most commonly used advanced airway methods today. For an ideal glottis view in direct laryngoscopy, the mouth and larynx should be in alignment. For this, longitudinal flexion and head extension maneuvers are performed. Reasons such as the clinical situation during intubation and the anatomical variation in the patient may prevent this maneuver from being performed.
McGrath videolaryngoscopyDirect laryngoscopyIt is a portable videoryngoscope weighing only 325 grams. The CameraStickTM component consists of a light source and a miniature camera, and the image is displayed on a 1.7 inch LCD (Liquid Crystal Display) screen mounted on top of the laryngoscope handle. At the same time, the LCD screen maintains visual contact with the patient and the laryngoscope, can be rotated up to 90°, allowing the user to work in a comfortable posture while performing tracheal intubation. The blade length is suitable for children over 5 years old and adults, thus reducing the trouble of storing different sized blades in the emergency intubation trolley. The blades are sterile and there is no risk of contamination as they are disposable.
C-MAC videolaryngoscopyC-MAC videolaryngoscopyConsidering the importance of first attempt success in intubation, their use in emergency airway management has increased due to the high first attempt success rate in C-MAC VLs. In patients with cervical spine injury, semi-rigid collars used to prevent neck extension and neck movements cause poor laryngeal vision with Direct laryngoscope and difficulty intubation. C-MAC Video laryngoscope provides a better laryngeal view in these patients
McGrath videolaryngoscopyC-MAC videolaryngoscopyIt is a portable videoryngoscope weighing only 325 grams. The CameraStickTM component consists of a light source and a miniature camera, and the image is displayed on a 1.7 inch LCD (Liquid Crystal Display) screen mounted on top of the laryngoscope handle. At the same time, the LCD screen maintains visual contact with the patient and the laryngoscope, can be rotated up to 90°, allowing the user to work in a comfortable posture while performing tracheal intubation. The blade length is suitable for children over 5 years old and adults, thus reducing the trouble of storing different sized blades in the emergency intubation trolley. The blades are sterile and there is no risk of contamination as they are disposable.
Direct laryngoscopyC-MAC videolaryngoscopyMacintosh laryngoscopy is still one of the most commonly used advanced airway methods today. For an ideal glottis view in direct laryngoscopy, the mouth and larynx should be in alignment. For this, longitudinal flexion and head extension maneuvers are performed. Reasons such as the clinical situation during intubation and the anatomical variation in the patient may prevent this maneuver from being performed.
McGrath videolaryngoscopyMcGrath videolaryngoscopyIt is a portable videoryngoscope weighing only 325 grams. The CameraStickTM component consists of a light source and a miniature camera, and the image is displayed on a 1.7 inch LCD (Liquid Crystal Display) screen mounted on top of the laryngoscope handle. At the same time, the LCD screen maintains visual contact with the patient and the laryngoscope, can be rotated up to 90°, allowing the user to work in a comfortable posture while performing tracheal intubation. The blade length is suitable for children over 5 years old and adults, thus reducing the trouble of storing different sized blades in the emergency intubation trolley. The blades are sterile and there is no risk of contamination as they are disposable.
Direct laryngoscopyMcGrath videolaryngoscopyMacintosh laryngoscopy is still one of the most commonly used advanced airway methods today. For an ideal glottis view in direct laryngoscopy, the mouth and larynx should be in alignment. For this, longitudinal flexion and head extension maneuvers are performed. Reasons such as the clinical situation during intubation and the anatomical variation in the patient may prevent this maneuver from being performed.
C-MAC videolaryngoscopyMcGrath videolaryngoscopyConsidering the importance of first attempt success in intubation, their use in emergency airway management has increased due to the high first attempt success rate in C-MAC VLs. In patients with cervical spine injury, semi-rigid collars used to prevent neck extension and neck movements cause poor laryngeal vision with Direct laryngoscope and difficulty intubation. C-MAC Video laryngoscope provides a better laryngeal view in these patients
C-MAC videolaryngoscopyDirect laryngoscopyConsidering the importance of first attempt success in intubation, their use in emergency airway management has increased due to the high first attempt success rate in C-MAC VLs. In patients with cervical spine injury, semi-rigid collars used to prevent neck extension and neck movements cause poor laryngeal vision with Direct laryngoscope and difficulty intubation. C-MAC Video laryngoscope provides a better laryngeal view in these patients
Primary Outcome Measures
NameTimeMethod
Intraocular pressure-5Intraocular pressure will be measured at 10 minutes after intubation

Right and left intraocular pressures will be measured with a Tono-pen (AVIA) (Reichert Technologies, Depew, NY, USA) device by an ophthalmologist unaware of the patient group. Initial intraocular pressure value will measured without using any sedative drugs. An ophthalmologist, unaware of the randomization, measured intraocular pressure using ocular sonography. It will be measured as intraocular pressure: mmHg.

Intraocular pressure-2Intraocular pressure will be measured at just before laryngoscopy and intubation

Right and left intraocular pressures will be measured with a Tono-pen (AVIA) (Reichert Technologies, Depew, NY, USA) device by an ophthalmologist unaware of the patient group. Initial intraocular pressure value will measured without using any sedative drugs. An ophthalmologist, unaware of the randomization, measured intraocular pressure using ocular sonography. It will be measured as intraocular pressure: mmHg.

Intraocular pressure-3Intraocular pressure will be measured at immediately after intubation

Right and left intraocular pressures will be measured with a Tono-pen (AVIA) (Reichert Technologies, Depew, NY, USA) device by an ophthalmologist unaware of the patient group. Initial intraocular pressure value will measured without using any sedative drugs. An ophthalmologist, unaware of the randomization, measured intraocular pressure using ocular sonography. It will be measured as intraocular pressure: mmHg.

Intraocular pressure-1Intraocular pressure will be measured at before induction

Right and left intraocular pressures will be measured with a Tono-pen (AVIA) (Reichert Technologies, Depew, NY, USA) device by an ophthalmologist unaware of the patient group. Initial intraocular pressure value will measured without using any sedative drugs. An ophthalmologist, unaware of the randomization, measured intraocular pressure using ocular sonography. It will be measured as intraocular pressure: mmHg.

Intraocular pressure-4Intraocular pressure will be measured at 5 minutes after intubation

Right and left intraocular pressures will be measured with a Tono-pen (AVIA) (Reichert Technologies, Depew, NY, USA) device by an ophthalmologist unaware of the patient group. Initial intraocular pressure value will measured without using any sedative drugs. An ophthalmologist, unaware of the randomization, measured intraocular pressure using ocular sonography. It will be measured as intraocular pressure: mmHg.

Secondary Outcome Measures
NameTimeMethod
Optic nerve diameter measurement-2Optic nerve diameter measurement-2 will be measured at just before laryngoscopy and intubation

Optic nerve diameter measurements will be made from the transverse and sagittal planes of both eyes using a linear 6-12 MHz transducer (EsaoteMyLabFive, Genoa, Italy). An ophthalmologist, unaware of the randomization, measured optic nerve diameter using ocular sonography. It will be measured as optic nerve sheath diameter: mm.

Optic nerve diameter measurement-5Optic nerve diameter measurement-5 will be measured at 10 minutes after intubation

Optic nerve diameter measurements will be made from the transverse and sagittal planes of both eyes using a linear 6-12 MHz transducer (EsaoteMyLabFive, Genoa, Italy). An ophthalmologist, unaware of the randomization, measured optic nerve diameter using ocular sonography. It will be measured as optic nerve sheath diameter: mm.

Optic nerve diameter measurement-3Optic nerve diameter measurement-3 will be measured at immediately after intubation

Optic nerve diameter measurements will be made from the transverse and sagittal planes of both eyes using a linear 6-12 MHz transducer (EsaoteMyLabFive, Genoa, Italy). An ophthalmologist, unaware of the randomization, measured optic nerve diameter using ocular sonography. It will be measured as optic nerve sheath diameter: mm.

Optic nerve diameter measurement-4Optic nerve diameter measurement-4 will be measured at 5 minutes after intubation

Optic nerve diameter measurements will be made from the transverse and sagittal planes of both eyes using a linear 6-12 MHz transducer (EsaoteMyLabFive, Genoa, Italy). An ophthalmologist, unaware of the randomization, measured optic nerve diameter using ocular sonography. It will be measured as optic nerve sheath diameter: mm.

Optic nerve diameter measurement-1Optic nerve diameter measurement-1 will be measured at before induction

Optic nerve diameter measurements will be made from the transverse and sagittal planes of both eyes using a linear 6-12 MHz transducer (EsaoteMyLabFive, Genoa, Italy). An ophthalmologist, unaware of the randomization, measured optic nerve diameter using ocular sonography. It will be measured as optic nerve sheath diameter: mm.

Trial Locations

Locations (1)

Inonu University Medical Faculty

🇹🇷

Malatya, Turkey

© Copyright 2025. All Rights Reserved by MedPath