Effects of Intubation on Intra-ocular Pressure and Optic Nerve Sheath Diameter ([Intubation])

Inonu University

Status: Completed

Conditions: Intraocular Pressure

Treatments: Procedure: C-MAC videolaryngoscopy; Procedure: McGrath videolaryngoscopy; Device: Direct laryngoscopy

Study type: Interventional

Funder types: Other

Identifiers

NCT05763056

ekaraaslan4

Details and patient eligibility

About

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.

Full 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.

Enrollment: 120 patients

Sex: All

Ages: 18 to 65 years old

Volunteers: Accepts Healthy Volunteers

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

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Quadruple Blind

---

120 participants in 3 patient groups

McGrath videolaryngoscopy

Active Comparator group

Description:

It 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.

Treatment:

Procedure: C-MAC videolaryngoscopy

Procedure: McGrath videolaryngoscopy

Device: Direct laryngoscopy

C-MAC videolaryngoscopy

Active Comparator group

Description:

Considering 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

Treatment:

Procedure: C-MAC videolaryngoscopy

Procedure: McGrath videolaryngoscopy

Device: Direct laryngoscopy

Direct laryngoscopy

Active Comparator group

Description:

Macintosh 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.

Treatment:

Procedure: C-MAC videolaryngoscopy

Procedure: McGrath videolaryngoscopy

Device: Direct laryngoscopy