Nasal Oxygen Therapy After Cardiac Surgery

Study Overview
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Brief Summary
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NOTACS aims to determine if prophylactic use of high-flow nasal therapy (for a minimum of 16 hours after tracheal extubation, inclusive of up to one hour off randomised therapy for transfers around the hospital and/or physio mobilisation) increases days at home in the first 90 days after surgery, for adult patients undergoing cardiac surgery who are at high risk of postoperative pulmonary complications. The study also incorporates a health economic analysis to estimate the incremental cost-effectiveness and cost-utility of HFNT versus standard oxygen therapy at 90 days, from the view-point of the public sector, NHS and patients.

Detailed Description
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Patients undergoing cardiac surgery are at significant risk of postoperative pulmonary complications that may lead to prolonged ICU and hospital stay and increase mortality. The incidence of respiratory complications may be three to four times more common in patients with intrinsic respiratory disease and lower airway obstruction (including asthma or chronic obstructive pulmonary disease (COPD)), or obese patients or current heavy smokers (> 10 pack years). High-flow nasal therapy (HFNT) is increasingly used as a non-invasive form of respiratory support. It delivers low level, flow-dependent positive airway pressure, and is much better tolerated by patients than alternatives such as continuous positive airway pressure (CPAP) or non-invasive ventilation. Patients can talk, eat, drink and walk whilst using HFNT. However, there is equipoise regarding its prophylactic use and effect on important patient-centred outcomes. Before the intervention is recommended for routine NHS use in cardiac surgery patients at high risk of pulmonary complications, whether it improves patient-related outcomes and is cost effective in a UK setting needs to be assessed.

Official Title
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Effect of High-Flow Nasal Therapy on Patient-Centered Outcomes in Patients at High Risk of Postoperative Pulmonary Complications After Cardiac Surgery: A Multicentre Randomised Trial

Conditions
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Cardiac Valve Disease, Coronary Artery Disease, Respiratory Failure

Intervention / Treatment
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* Device: High Flow Nasal Therapy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Aged 18 years or over. Undergoing any elective or urgent first-time or redo cardiac surgery performed on cardiopulmonary bypass Have one or more clinical risk factors for postoperative pulmonary complications (COPD, asthma, lower respiratory tract infection in last 4 weeks as defined by use of antibiotics, body mass index ≥35 kg/m2 , current (within the last 6 weeks) heavy smoker (> 10 pack years)) (47, 48). Asthma is a disease characterized by recurrent attacks of breathlessness and wheezing, and patients will have been prescribed medication by inhalers or nebulisers (either bronchodilators or steroids). Chronic Obstructive Pulmonary Disease (COPD) is an umbrella term used to describe chronic lung diseases that cause limitations in lung airflow. The more familiar terms 'chronic bronchitis' and 'emphysema' are no longer used but are now included within the COPD 13 diagnosis. The most common symptoms of COPD are breathlessness, or a 'need for air', excessive sputum production, and a chronic cough. Patients suitable for the NOTACS study will have been prescribed medication by inhalers or nebulisers (either bronchodilators or steroids). Exclusion Criteria: Requiring home oxygen therapy. Deep hypothermic circulatory arrest planned Contraindication to HFNT, e.g. nasal septal defect. Requirement for home ventilatory support (including: HFNT, CPAP, BiPAP) Requiring emergency cardiac surgery defined as surgery required within 24 hours of the decision to operate. Patients not fluent in English.

Ages Eligible for Study
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Minimum Age: 18 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: Supportive Care
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: An adaptive, multicentre, parallel group randomised controlled clinical trial with embedded cost-effectiveness analysis.
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: Standard Oxygen Therapy<br>Standard oxygen therapy arm patients will be given 30-40% inspired O2 and flow 2-6 l/min via nasal prongs or non-rebreathing mask (not humidified and not heated) post extubation. Monitoring of saturations, respiratory rate and arterial gases will happen 15 minutes post extubation and then as per local policy thereafter. If saturations < 93% then FiO2 will be increased as per respiratory escalation protocol. Standard oxygen therapy will be given for a minimum of 16 hours post extubation. | |
| Other: High-Flow Nasal Therapy<br>High-flow nasal therapy arm patients will be given AIVRO 2 high flow oxygen therapy machines post extubation, start at 30-40% inspired O2 and flow 30 l/min then up to 50 l/min over 5-10 min. Monitoring of saturations, respiratory rate and arterial gases will happen after 15 minutes post extubation and then as per local policy thereafter. If saturations < 93% then increase FiO2 as per respiratory escalation protocol. High flow nasal therapy will be given for a minimum of 16 hours post extubation. | Device: High Flow Nasal Therapy<br>* High Flow Nasal Oxygen (Airvo2 Device)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Days alive and at home in the first 90 days after surgery, for adult patients undergoing cardiac surgery who are at high risk of postoperative pulmonary complications who either receive High flow nasal therapy or Standard oxygen therapy | Number of days at home in the first 90 days after surgery, measured by the patient facing Patient Location and Medication Diary at 90 days | 90 days | 
| Incremental cost-effectiveness and cost-utility of High flow nasal therapy versus Standard therapy for patients undergoing cardiac surgery who are at high risk of postoperative pulmonary complications at 90 days | Health Economic analysis to estimate the incremental cost-effectiveness and cost-utility of High flow nasal therapy versus Standard therapy at 90 days from the view point of the public sector, NHS and patient, measured by using Patient and Family Resource Use patient facing Questionnaires at 90 days. | 90 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Estimates of the incremental cost-effectiveness and cost-utility of High flow nasal therapy versus standard oxygen therapy for adult patients undergoing cardiac surgery who are at high risk of postoperative pulmonary complications at 30 days. | Health Economic analysis to estimate the incremental cost-effectiveness and cost-utility of High flow nasal therapy versus Standard therapy at 90 days from the view point of the public sector, NHS and patient, measured by using Patient and Family Resource Use patient facing Questionnaires at 30 days. | 30 days | 
| Incidence of mortality, pulmonary complications, intensive care re-admission rate, length of hospital and intensive care stay . | Mortality measured by the incidence of death reported from patient follow-up and medical records at 30 and 90 days. Incidence of postoperative pulmonary complications measured using medical notes during primary admission to hospital. ICU re-admission rate measured using the in-patient diary eCRF at any time during primary hospital admission Length of ICU stay (days) measured using the in-patient diary eCRF during primary hospital admission Length of hospital stay (days) measured using the in-patient diary eCRF during primary hospital admission | Discharge on average 7 days post operation, 30 and 90 days | 
| Incidence of major complications including sepsis, renal failure, myocardial infarction and stroke. | Incidence of stroke measured from patient follow-up and medical records at 30 and 90 days Incidence of sepsis measured from patient follow-up and medical records at 30 and 90 days Incidence of myocardial infarction measured from patient follow-up and medical records at 30 and 90 days | 30 and 90 days | 
| Incidence of readmission to hospital rate. | Incidence of readmission to hospital rate, measured using the in-patient diary eCRF during primary hospital admission and patient location and medication diary for patient completion up to 90 days | 90 days | 
| Statistical analysis of oxygenation as measured by the ROX Index (as defined as Sp02/Fi02 to respiratory rate ratio). | Oxygenation measured by ROX Index (defined as Sp0₂/Fi0₂ to respiratory rate ratio) at 2, 6, 12, 24 and 48 hours post-extubation | 2,6,12,24,and 48 hours post extubation | 
| Statistical analysis of patient-centered outcomes as measured using the EQ-5D-5L | Patient-reported outcomes measured using the EQ-5D-5L questionnaire at baseline, discharge, 30 and 90 days 12. Quality of Survival will be as measured using ED-5D-5L Quality adjusted life years (QALYs). | Discharge on average 7 days post operation, 30 and 90 days | 
| Statistical analysis of patient-centered outcomes as measured using the EQ-5D-5L Quality of Survival | Quality of Survival will be as measured using ED-5D-5L Quality adjusted life years (QALYs). | Discharge on average 7 days post operation, 30 and 90 days | 
| Statistical Analysis to determine if prophylactic use of high- flow nasal oxygen reduces health service and resource use. | Health service and resource use measured using Patient and Family Resource Use Questionnaires at baseline, discharge, 30 and 90 days | Discharge on average 7 days post operation, 30 and 90 days | 
| Statistical analysis of patient level of assistance needed with activities of daily living post surgery as measured using BARTHEL questionnaire. | Patient level of assistance needed with activities of daily living, measured using the BARTHEL questionnaire at baseline, discharge, 30 and 90 day | Discharge on average 7 days post operation, 30 and 90 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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High-Flow Nasal Therapy, High-Flow Nasal Oxygen, Cardiac Surgery, Pulmonary Complications