The Performance of Two Oxygen Delivery Devices Used After General Anesthesia.

Study Overview
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Brief Summary
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After general anesthesia, there are the risks for airway obstruction, hypoventilation, atelectasis, ventilation-perfusion mismatch, hypercarbia and hypoxemia,so oxygen supplement in PACU seems necessary. This study aim is to compare the two methods of oxygen supplement which are 1.nasal cannula at O2 flow 4 L/min. 2.oxygen mask with O2 flow 5 L/min. The hypothesis in this study is the 2 methods can equally provide effective oxygen supplement to prevent anesthesia-related hypoxemia. Choosing nasal cannula would be reasonable because it is cheaper and more comfortable to patient.

Detailed Description
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The incidence and causes of hypoxemia in PACU will be identified, if necessary, a higher flow or changing oxygen delivery system can be used to prevent and treat hypoxemia. If any patients fail from oxygen weaning protocol in PACU and need longer oxygen therapy at ward, the duration of oxygen therapy will be recorded and also the compliance with oxygen delivery devices.

Official Title
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The Performance Comparison of Two Oxygen Delivery Devices [Nasal Cannula and Mask] Used After General Anesthesia.

Conditions
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Hypoxemia

Intervention / Treatment
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* Device: oxygen mask
* Device: oxygen cannula


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: General anesthesia Age 18-70 years American Society of Anesthesiology (ASA)physical status 1-3 Elective case Exclusion Criteria: ASA physical status class 4 or more Unstable pulmonary diseases BMI > 35 kg/m2 oxygen saturation < 94% when breathing in room air Respiratory muscle weakness eg.myasthenia gravis Central nervous system abnormalities eg.drowsiness, hypoventilation Patients who have been intubated or needed ventilatory support before operation Plan to remain intubated after the operation Intracranial, intrathoracic and upper abdomen surgery Patients who nasogastric tube is inserted Airway problems eg. sinusitis Nasal cavity related surgery or nasal packing eg. endoscopic sinus surgery Patient refusal

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 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: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: oxygen mask<br>Oxygen mask with oxygen flow 5 L/min will be given to allocated post general anesthesia patients. The incidence and causes of hypoxemia will be recorded. | Device: oxygen mask<br> <br> * Other names: Oxygen mask or simple mask;|
| Active Comparator: Oxygen cannula<br>Oxygen cannula with oxygen flow 4 L/min will be given to allocated post general anesthesia patients. The incidence and causes of hypoxemia will be recorded. | Device: oxygen cannula<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of Participants With Hypoxemia in Both Groups | Hypoxemia is defined as oxygen saturation < 94%. We record number of participants with hypoxemia in both groups | In PACU (1 hr after anesthesia) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The Causes of Hypoxemia | Causes of hypoxemia in each participant in PACU will be recorded | In PACU (1 hr after anesthesia) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Oxygen, PACU, Hypoxemia