Effectiveness of Modified Ophthalmic Draping Method in Preventing Carbon Dioxide Accumulation in Patient Undergoing Eye Surgery Under Local Anesthesia

Study Overview
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Brief Summary
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The investigators hypothesize that this modified ophthalmic draping will reduce the accumulation and rebreathing of carbon dioxide during eye surgery.

Detailed Description
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Majority of eye surgery has been widely done under local anesthesia provided by the ophthalmologist with or without sedation.The surgical drapes used often covers the patients face and beyond in order to maintain sterility of the surgical field. This can lead to accumulation of carbon dioxide under ophthalmic drapes due to the exhaled carbon dioxide escapes incompletely through the drapes;hence results in an increase of carbon dioxide in the ambient air surrounding the patient's head.This causes an increase in arterial carbon dioxide partial pressure and thus hyperventilation and patient discomfort with restlessness and unable to stay still during the surgery. In recent years,several types of ophthalmic drapes have been produced.This study is look for possible difference in accumulation of carbon dioxide under the standard ophthalmic drapes compared to the modified draping.

Official Title
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Effectiveness of Modified Ophthalmic Draping Method in Preventing Carbon Dioxide Accumulation in Patient Undergoing Eye Surgery Under Local Anesthesia

Conditions
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To Prevent Hypothermia During Opthalmology Surgery., To Prevent Hypercarbia Under the Opthalmology Drape During Surgery.

Intervention / Treatment
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* Device: forced air warmer (Bair Hugger)
* Device: warming blanket


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: - ASA physical status I,II OR III,adult aged 40 to 80 years old,scheduled to undergo elective eye surgery under local anaesthetic at UMMC will be enrolled in this study. Exclusion Criteria: Pre-existing pulmonary disease,psychological disorders,neurological disorder and patient required sedation.

Ages Eligible for Study
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Minimum Age: 40 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: drape with forced air warmer<br>forced air warmer placed under the chin before draping, inflated after draping completed. | Device: forced air warmer (Bair Hugger)<br>* forced air warmer placed under the chin before draping, forced air warmer inflated after draping is completed.<br>* Other names: Forced air warmer brand - Bair Hugger;|
| Placebo Comparator: drape with warming blanket<br>warming blanket placed on torso of patient under the drape. | Device: warming blanket<br>* warming blanket placed on torso of patient under the drape.<br>* Other names: warming blanket brand - Thermamed warming system;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| transcutaneous CO2 level in mmHg under surgical drape with forced air warmer | baseline transcutanoeus CO2 level will be taken before surgical draping. After draping, CO2 level will be measured with transcutaneous CO2 frome earlobe at 10 minutes, 15 minutes, and 30 minutes. | 10 minutes, 15 minutes, 30 minutes |