CClinicalTrials.gg
CompletedNCT05571683Updated Mar 13, 2024

Cerebral Oxymeter and End Tidal Carbondioxide Values Under Surgical Drapes With and Without Past COVID-19 Infection

An observational study in Cataract Extraction, Anesthesia, Local and Optic Nerve Sheath, sponsored by Duzce University. Completed at 1 site in Turkey. Open to participants aged 18 Years to 80 Years. Per ClinicalTrials.gov, last updated 2024-03-13.

Sponsored by Duzce University · Observational

Study type
Observational
Model
Cohort
Time perspective
Prospective
Enrollment
80
Ages
18 Years to 80 Years
Sex
All
01

Study summary

Today, phacoemulsification has become the most commonly applied method in the treatment of cataract, which is considered as a public health problem. Since the eyelid margins can be a source for pathogens in phacoemulsification surgery draping after skin sterilization is applied to remove the eyelashes from the operation area. Since surgical drapes are airtight, carbon dioxide (CO2) accumulation occurs under the drape in patients under local anesthesia. During the operation, if the end tidal CO2 pressure value rises, this can lead to hyperventilation and tachycardia and also increase the intraocular pressure which is undesirable in eye surgery. In our study, in order to observe and compare undesirable conditions, regional tissue oxygenation saturation (rSO2) will be determined non-invasively with Transcutaneous Near Infrared Spectroscopy (NIRS) technology , which allows real-time monitoring. Changes in the partial pressure of carbon dioxide (PaCO2) are strongly vaso-active, resulting in changes in cerebral blood volume and hence intracranial pressure.

As the optic nerve sheath is an extension of the brain dura mater, the diameter of the sheath expands in case of increased intracranial pressure. Evaluation of the optic nerve sheath with ultrasound allows us to obtain information about intracranial pressure. For optic nerve sheath diameter, measurements above 5.0 mm in adult patients are generally considered as increased intracranial pressure.

COVID-19 is a global epidemic caused by SARS-CoV-2 that we are still fighting. Although it is a multisystemic disease, it is important in terms of its effects on pulmonary function and the continuity of pulmonary symptoms and findings after this disease has been overcome.

In our study, End-Tidal CO2 and cerebral oximetry (NIRS) values will be determined and compared between the groups that received 2lt/min and 4lt/min nasal oxygen support during cataract surgery performed using draping under local anesthesia in patients who had COVID-19, recovered and never had. It was aimed to evaluate and compare the values of optic nerve sheath diameter increase.

Read the detailed description

After the patients who meet the specified criteria are informed about the study, the volunteers who agreed to participate and signed informed consent will be included in the study.

After all volunteers are taken to the operation room, vascular access will be established, electrocardiography, pulse oximetry, non-invasive blood pressure, end-tidal carbon dioxide and cerebral oximetry (with the neck in the supine position in the neutral position and 2 probes placed on the forehead) are monitored without any medication (Figure 1). The optic nerve sheath diameter will be measured by the ultrasonography device in the inventory of the Department of Anesthesiology and Reanimation by the researchers, basal heart rate (CTA), peripheral oxygen saturation (SpO2), systolic (SBP) and diastolic blood pressure (DBP), end- Tidal carbon dioxide (ETCO2), cerebral oxygen saturation (SO) values will be recorded. All measurements except optic nerve sheath diameter will be recorded and repeated at 5 minute intervals throughout the operation. During this time, no drugs or invasive methods will be used.

During the operation, the volunteers in both groups will be randomly divided into 2 subgroups and 2L/min and 4 L/min nasal oxygen support will be provided. At the end of the operation, the ultrasonographic optic nerve sheath diameter measurement will be repeated immediately after the dressing is removed.

02

Conditions studied

  • Cataract Extraction
  • Anesthesia, Local
  • Optic Nerve Sheath

Browse trials for

Keywords

  • cataract extraction
  • Anesthesia, Local
  • optic nerve sheath
  • carbon dioxide
  • cerebral oxygen saturation
03

In context

Cataract

1,701 studies on the registry are indexed under Cataract; 230 are open to participants now.

This study's enrollment of 80 is close to the median of 81 across 484 observational studies indexed under Cataract.

Browse Cataract studies →

Lead sponsor

Duzce University is the lead sponsor of 70 studies on the registry; 12 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 80 Years
Sexes eligible
All
Accepts healthy volunteers
No
Sampling method
Probability sample

Study population

A total of 80 patients who will undergo phacoemulsification surgery under local anesthesia will be included in the study.

40 of the patients will be individuals who have had Covid-19 infection and recovered, and 40 will be individuals who have not had Covid-19 infection.

Inclusion criteria

  • Patients over the age of 18 who will undergo cataract surgery, who are in I, II and III risk groups according to the American Society of Anesthesiologists (ASA) classification

Exclusion criteria

Exclusion Criteria:

  • Patients for whom Intensive Care Unit (ICU) indication is prescribed
  • Chronic obstructive pulmonary disease
  • Past coronary arterial by-pass graft history
  • Hemoglobinopathies
  • Neurodegenerative diseases
05

Study design

Observational model
Cohort
Time perspective
Prospective
Enrollment
80 participants (actual)
Patient registry
No

Groups and cohorts

  • recovered from covid-19, 2 l/min oxygen support

    20 patients, who recovered from COVID-19 will be supported with 2 l/min oxygen during the operation under the drapes. Electrocardiography, pulse oximetry, non-invasive blood pressure, end-tidal carbon dioxide and cerebral oximetry will be monitored and optic nerve sheath diameter will be measured before and after surgical procedure. All measurements except optic nerve sheath diameter will be recorded and repeated at 5 minute intervals throughout the operation.

    Other: oxygen support

  • no covid anamnese, 2 l/min oxygen support

    20 patients with no COVID-19 anamnese will be supported with 2 l/min oxygen during the operation under the drapes. Electrocardiography, pulse oximetry, non-invasive blood pressure, end-tidal carbon dioxide and cerebral oximetry will be monitored and optic nerve sheath diameter will be measured before and after surgical procedure. All measurements except optic nerve sheath diameter will be recorded and repeated at 5 minute intervals throughout the operation.

    Other: oxygen support

  • recovered from covid-19, 4 l/min oxygen support

    20 patients, who recovered from COVID-19 will be supported with 4 l/min oxygen during the operation under the drapes. Electrocardiography, pulse oximetry, non-invasive blood pressure, end-tidal carbon dioxide and cerebral oximetry will be monitored and optic nerve sheath diameter will be measured before and after surgical procedure. All measurements except optic nerve sheath diameter will be recorded and repeated at 5 minute intervals throughout the operation.

    Other: oxygen support

  • no covid anamnese, 4 l/min oxygen support

    20 patients with no COVID-19 anamnese will be supported with 4 l/min oxygen during the operation under the drapes. Electrocardiography, pulse oximetry, non-invasive blood pressure, end-tidal carbon dioxide and cerebral oximetry will be monitored and optic nerve sheath diameter will be measured before and after surgical procedure. All measurements except optic nerve sheath diameter will be recorded and repeated at 5 minute intervals throughout the operation.

    Other: oxygen support

Interventions

  • Otheroxygen support

    40 patients (2 arms) will be supported with 2 l/min oxygen and the other 2 arms (40 patients) will be supported with 4 l/min oxygen under the surgical drapes.

06

What researchers measure

Primary outcomes

  1. Change from baseline in the end tidal carbon dioxide values

    End tidal carbondioxide values will be measured continously during the operation with a capnograph device via nasal cannula non-invasively and recorded.

    Time frame: End tidal carbondioxide values will be measured continously during the operation and recorded in every 5 minutes from the draping to the end of the operation.

  2. Change from baseline in the cerebral oxygenisation values

    Cerebral oxygenisation values will be measured continously during the operation with a transcutaneous near infrared spectroscope device (NIRS) via a transcutaneous probe placed on the frontal bone non-invasively and recorded.

    Time frame: Cerebral oxygenisation values will be measured continously during the operation and recorded in every 5 minutes from the draping to the end of the operation.

  3. Change from baseline in the optic nerve sheath diameter

    The optic nerve sheath diameter will be measured ultrasonographically by the same experienced researcher before and on the end of the operation.

    Time frame: 2 times, once before acceptance in the operation room, and secondly on the end of the operation before undraping.

07

Study locations

1 site
  • Duzce University Faculty of Medicine
    Duzce, Düzce 81000, Turkey
08

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Mar 13, 2024, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT05571683
Lead sponsor
Duzce University
Responsible party
Özlem Ersoy Karka (Assistant Professor, Duzce University) — Principal investigator
First posted
Oct 7, 2022
Start date
Jun 6, 2022
Primary completion
Dec 16, 2023
Completion
Dec 16, 2023
Last update
Mar 13, 2024

Study contacts

Özlem Ersoy Karka
principal investigator · Düzce University Faculty of Medicine

Oversight

FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is completed, as verified in Mar 2024. You cannot join it, but the record below documents what was studied.

Follow this study

Get an email when the registry record changes — status, dates, results — or when someone posts here.

Sign in to follow

Discussion

Questions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.

Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.

Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.

Start the discussion