Efficacy of HFNC as an Alternative to CPAP Therapy in Surgical Patients With Suspected Moderate to Severe OSA

Study Overview
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Brief Summary
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High flow, humidified, temperature-regulated nasal insufflation is not a new concept. It is used widely in the treatment of hypoxaemic respiratory failure in critically ill patients, as an alternative to non-invasive positive ventilation via face or nasal mask. Recently, its use has been extended to the perioperative setting for pre-oxygenation and prolonging apnoeic time to desaturation. Both CPAP and high flow nasal cannula insufflation devices are licensed for use clinically in Singapore. We conduct this pilot study because its perioperative use in our adult OSA population is currently not well-defined.

Detailed Description
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Continuous positive airway pressure (CPAP) therapy is the only treatment for obstructive sleep apnoea (OSA) shown to reduce its long-term adverse effects on the cardiovascular system. However, due to difficult patient-mask interface and discomfort, compliance rate amongst patients with OSA is low, and reported to be only between 20-50%. High flow, humidified, temperature-regulated nasal cannula insufflation (of air or oxygen) is a well-documented and safe treatment in intensive care, paediatrics and respiratory medicine for patients with hypoxaemic respiratory failure. Its use in adult patients with obstructive sleep apnoea, especially in the perioperative setting is not well studied. Our hospital has a ''fast-track'' protocol for OSA patients who require surgery. They are started on CPAP therapy 2 to 5 days prior to surgery and in the immediate post operative period (ie. perioperatively). If these patients are non-compliant to the CPAP mask device, high flow nasal insufflation is a possible alternative treatment. We aim to randomise these patients into 4 groups, receiving conventional CPAP face mask or high flow nasal cannula at 3 flow rates, and study them with respect to incidence and number of documented desaturations. In addition, patient satisfaction, compliance to device and any adverse events will be monitored.

Official Title
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Continuous Positive Airway Pressure Therapy Via Conventional CPAP Face Mask Versus High Flow Nasal Cannula in OSA Patients on the First Postoperative Night- a Pilot Randomised Study

Conditions
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OSA

Intervention / Treatment
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* Device: CPAP face mask
* Device: High flow nasal cannula (HFNC)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients aged 21-85 years old presenting for elective surgery. Suspected/possible OSA patients who are enrolled in the fast-track OSA protocol in the pre-assessment clinic Patients started on CPAP therapy at least one day pre-operatively Patients who are admitted to the High Dependency unit for postoperative monitoring. Exclusion Criteria: Patients with nasal obstruction. Patients undergoing nasal or facial surgery, or surgery to treat OSA (eg. uvulopalatopharyngoplasty). Patients who already require a higher oxygen concentration (FiO2 > 0.21) preoperatively.

Ages Eligible for Study
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Minimum Age: 21 Years
Maximum Age: 85 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: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: OSA support via CPAP face mask<br>Auto-titrated according to the settings made by sleep physicians, FiO2 0.21 | Device: CPAP face mask<br>* Two types of CPAP therapy for OSA support are compared; CPAP face mask vs HFNC at different flow rates<br>|
| Active Comparator: OSA support via HFNC at 20 L/min<br>High flow nasal insufflation of air (FiO2 0.21) at 20 L/min | Device: High flow nasal cannula (HFNC)<br>* Two types of CPAP therapy for OSA support are compared; CPAP face mask vs HFNC at different flow rates<br>* Other names: Optiflow™ High Flow therapy; Fisher and Paykel;|
| Active Comparator: OSA support via HFNC at 30 L/min<br>High flow nasal insufflation of air (FiO2 0.21) at 30 L/min | Device: High flow nasal cannula (HFNC)<br>* Two types of CPAP therapy for OSA support are compared; CPAP face mask vs HFNC at different flow rates<br>* Other names: Optiflow™ High Flow therapy; Fisher and Paykel;|
| Active Comparator: OSA support via HFNC at 40 L/min<br>High flow nasal insufflation of air (FiO2 0.21) at 40 L/min | Device: High flow nasal cannula (HFNC)<br>* Two types of CPAP therapy for OSA support are compared; CPAP face mask vs HFNC at different flow rates<br>* Other names: Optiflow™ High Flow therapy; Fisher and Paykel;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of participants with documented desaturations (defined as >4% drop from baseline) | Number of documented desaturations (defined as >4% below baseline) in OSA patients who receive CPAP face mask or high flow nasal insufflation on the first postoperative night | 10 hours (between 10pm on first postoperative night and 8am the following day) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of participants who need for supplemental oxygen and/ or the need for other interventions to reverse the desaturations. | Need for supplemental oxygen and/or the need for other interventions to reverse desaturations in OSA patients who receive CPAP face mask or high flow nasal insufflation on the first postoperative night | 10 hours (between 10pm on first postoperative night and 8am the following day) | 
| Patients' perceptions of the comfort of each device on scale of 0 to 100 | The patients' perceptions of the comfort of CPAP face mask and/ or high flow nasal insufflation | 10 hours (between 10pm on first postoperative night and 8am the following day) | 
| Number of participants with any adverse effects of the applied therapy in the immediate postoperative setting. | OSA patients who receive CPAP face mask or high flow nasal insufflation on the first | 10 hours (between 10pm on first postoperative night and 8am the following day) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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CPAP therapy, High flow nasal cannula