This site became the new on June 19th. Learn more.
Show more Menu IMPORTANT: Listing of a study on this site does not reflect endorsement by the National Institutes of Health. Talk with a trusted healthcare professional before volunteering for a study. Read more... Menu IMPORTANT: Talk with a trusted healthcare professional before volunteering for a study. Read more... Menu
Give us feedback

Application of Nasal Cannula With Oxygen Versus Air During Eye Surgery Under Local Anaesthetic

This study has been completed.
Information provided by:
University of Malaya Identifier:
First received: July 5, 2010
Last updated: August 15, 2011
Last verified: August 2011
The investigators hypothesize that this new nasal cannula will prevent lack of oxygen as well as reduce rebreathing of carbon dioxide under ophthalmic drapes during eye surgery.

Condition Intervention Phase
Hypoxia Hypercapnia Drug: oxygen Phase 1

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Factorial Assignment
Masking: Double (Participant, Investigator)
Primary Purpose: Health Services Research

Resource links provided by NLM:

Further study details as provided by University of Malaya:

Primary Outcome Measures:
  • Evidence of desaturation during intraoperative period under the drape [ Time Frame: Intraoperative period ]

Enrollment: 100
Study Start Date: May 2010
Study Completion Date: December 2010
Primary Completion Date: October 2010 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: oxygen Drug: oxygen
Subjects who are found to desaturate during treatment with air will be supplement with oxygen
Other Name: resuscitation for hypoxia
Placebo Comparator: air supplement Drug: oxygen
Subjects who are found to desaturate during treatment with air will be supplement with oxygen
Other Name: resuscitation for hypoxia

Detailed Description:

Surgery involvement the eye has widely been done under local anaesthesia provided by the ophthalmologists. Patients are often awake or mildly sedated during the surgery. However, due to the surgical drape which covers the patients face and beyond in order to maintain sterility of the surgical field, it may lead to hypoxia in these patients and retention of exhaled air within the confined space under the drape. This may lead to patient discomfort and the surgeon will face difficulty when the patient becomes restless and unable to be still for the surgery.

Various studies had been conducted using nasal cannula with oxygen or air which is administered to patients having cataract surgery under local anaesthetics and the results has so far been inconclusive.

One study evaluated the saturation of O2 in arterial blood, the partial pressure of O2 in arterial blood (PaO2), the partial pressure of CO2 in arterial blood (PaCO2) and the pH. The operative blood gas parameters were maintained in the air inhalation patients. Oxygen supplement caused significant increase in the saturation of O2 in arterial blood and in PaO2. There was no difference between the two groups in PaCO2. The pH of the arterial blood showed a statistically significant decrease in the patients with O2 supplement. This shift to more acidotic levels could cause central nervous system depression with reduced respiratory stimulus. Recommendation was to administer air rather than O2 to patients during cataract surgery.[1]

Another clinical trials have shown that O2 application by nasal cannula prevents hypoxia but not rebreathing of CO2 in patients undergoing eye surgery under local anaesthetics.[4]

In this clinical trial, we use Duo flow O2 + CO2 sampling cannula designed in a way to deliver O2 and sampling of expired CO2 gases from both nostril simultaneously. The aim of this study is to randomly administer O2 or air through a new nasal cannula to patients undergoing eye surgery under local anaesthetic and to evaluate the significance of O2 supplement and whether CO2 retention has an indirect effect to it.


Ages Eligible for Study:   40 Years to 80 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • (ASA) physical status I, II or III, adult age 40-80 years old group, scheduled to undergo elective eye surgery under local anaesthetic at UMMC will be enrolled in this study.

Exclusion Criteria:

  • pre-existing pulmonary diseases, Psychological disorders, Neurological disorders and patients required sedation.
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01157624

University Malaya Medical Center
Kuala Lumpur, Federal Teritory, Malaysia, 59100
Sponsors and Collaborators
University of Malaya
  More Information

Responsible Party: Tan Siaw Boon, Department of Anaesthesiology, University Malaya Identifier: NCT01157624     History of Changes
Other Study ID Numbers: nasalo2
Study First Received: July 5, 2010
Last Updated: August 15, 2011

Keywords provided by University of Malaya:
hypoxia or hypercarbia during surgery under the drape

Additional relevant MeSH terms:
Signs and Symptoms, Respiratory
Signs and Symptoms processed this record on September 21, 2017