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Completed

NCT Number: NCT05763056

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

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.

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Key information

Conditions

Intraocular Pressure

Age range

18 year–65 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Inonu University Medical Faculty

Malatya, 44090, Turkey (Türkiye)

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

McGrath videolaryngoscopy

Procedure

The McGrath video laryngoscope has a thin, disposable, clear, regularly shaped blade similar to a Macintosh blade and a large LCD display attached to the arm. It is lighter in weight and the Mc VL has a small camera at the tip, with a more compact screen and handle that can make tracheal intubation easier and faster in normal or difficult airway. The smaller volume, thinner and portrait screen helps reduce blind spots

C-MAC videolaryngoscopy

Procedure

The Macintosh blade is attached to the handle and the light beam is passed through the blade tip into a small metal guide tube indented 40 mm. The camera cable is connected to the control unit and the optical cable is connected to the light source. The video macintosh system is installed in a small trolley for easy portability of the device. The trolley supports an 8-inch monitor mounted on a rotating arm on the patient's left side. C-MAC VL devices can create continuous video recordings or static images on a secure removable digital card. The electronic module includes 2 buttons for photo and video shooting. In addition, the image of the C-MAC VL device can be viewed on other devices or recorded via a standard video output port. 3 C-MAC VL reusable metal macintosh blades (sizes 2 to 4) can be used for adult patients. These non-disposable knives have a closed design without gaps in terms of hygiene and have beveled edges to prevent tissue damage.

direct laryngoscopy

Device

During intubation with a direct laryngoscope (DL), the laryngoscope is inserted into the oral cavity from the right side of the mouth, the tongue is pushed to the left, and after advancing up to the vallecula, it hangs up and forward. In this way, the floor of the mouth and the epiglottis structure are removed from the field of view. If a straight blade laryngoscope is to be used, it is advanced so that the epiglottis remains under the blade after viewing the epiglottis (1). In DL, manipulations such as head extension, sniffing position, and compression of the cricoid cartilage may be required to facilitate visualization of the vocal folds. In 10-15% of the complications experienced during intubation with DL, there are problems related to the angle of view.

Primary outcomes

  1. Intraocular pressure-1

    Time frame: Intraocular 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.

  2. Intraocular pressure-2

    Time frame: Intraocular 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.

  3. Intraocular pressure-3

    Time frame: Intraocular 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.

  4. Intraocular pressure-4

    Time frame: Intraocular 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.

  5. Intraocular pressure-5

    Time frame: Intraocular 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.

Secondary outcomes

  1. Optic nerve diameter measurement-1

    Time frame: Optic 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.

  2. Optic nerve diameter measurement-2

    Time frame: Optic 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.

  3. Optic nerve diameter measurement-3

    Time frame: Optic 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.

  4. Optic nerve diameter measurement-4

    Time frame: Optic 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.

  5. Optic nerve diameter measurement-5

    Time frame: Optic 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.

Sponsors and collaborators

Lead sponsor

Inonu University

Other

Registry information

Official study title

Comparison of the Effects of Intubation With a Machintosh Laryngoscope, McGrath Videolaryngoscope and C-Mac Videolaryngoscope on Intra-ocular Pressure, Optic Nerve Sheath Diameter and Haemodynamic Parameters

Acronym: [Intubation]

Important dates

Study start
2023
Primary completion
2023
Study completion
2023
First posted
Mar 10, 2023
Registry last updated
Nov 9, 2023

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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