HFNC and Acute Hypercapnic Respiratory Failure

Study Overview
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Brief Summary
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High-flow nasal cannula (HFNC) enables delivering humidified gas at high-flow rates controlling the oxygen inspired fraction (FiO2). Its efficacy has been demonstrated in hypoxemic acute respiratory failure. However, little is known about its use in hypercapnic acute respiratory failure (ARF). Therefore, we aimed to evaluate the effect of using HFNC through Precision Flow equipment as first line of ventilatory support for COPD patients with hypercapnic acute respiratory failure.

Official Title
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High Flow Nasal Oxygen Therapy in Chronic Obstructive Pulmonary Disease (COPD) Patients With Acute Hypercapnic Respiratory Failure (AHRF)

Conditions
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High Flow Oxygen Therapy, Acute Hypercapnic Respiratory Failure, COPD Exacerbation

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Moderate to very severe COPD patients (GOLD 2 to 4) over 18 years old admitted to the ICU with hypercapnic ARF (PaCO2> 45 mmHg and respiratory acidosis [pH ≥7.30], with or without hypoxemia + one of the following: Respiratory Rate ≥25 cycles per minute, intercostal and / or supraclavicular recruitment, or thoraco-abdominal synchrony, no prior use of NIV) Exclusion Criteria: Patients less than 18 years old Mild COPD patients Absence of hypercapnia Kelly M Score > 3 Haemodynamic instability (despite fluid resuscitation) NIV or Invasive Mechanical Ventilation (IMV) (Need to use previously to HFNC) Contraindications to implement high-flow oxygen therapy.

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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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Need for non-invasive ventilation | The need and causes for non-invasive ventilation will be recorded in the all study period. | From inclussion study date until the first day of noninvasive ventilation use documented, after high flow oxygen therapy use or death date from any cause, whichever came first, assessed up to 4 weeks. | 
| Need for endotracheal intubation | The need and causes for endotracheal intubation will be recorded in the all study period. | From inclussion study date until the first day of endotracheal intubation documented, after high flow oxygen therapy use or death date from any cause, whichever came first, assessed up to 4 weeks. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Gas Exchange | pH will be recorded | Arterial blood gases will be recorded 1, 24 hours and every 24 hours after enrollment | 
| Gas Exchange | PaCO2 in milimeters of mercury (mmHg) will be recorded | Arterial blood gases will be recorded 1, 24 hours and every 24 hours after enrollment | 
| Gas Exchange | PaO2 in milimeters of mercury (mmHg) will be recorded | Arterial blood gases will be recorded 1, 24 hours and every 24 hours after enrollment | 
| Respiratory variables | Respiratory rate in numbers of breaths per minute (bpm) will be recorded | Respiratory variables will be recorded at 1, 2, 3, 6, 12, 24 hours and every 24 hours after enrollment | 
| Respiratory variables | Accessory muscular use (intercostal or supraclavicular) by YES or NO will be recorded | Respiratory variables will be recorded at 1, 2, 3, 6, 12, 24 hours and every 24 hours after enrollment | 
| Respiratory variables | Thoraco-abdominal asynchrony by YES or NO will be recorded | Respiratory variables will be recorded at 1, 2, 3, 6, 12, 24 hours and every 24 hours after enrollment | 
| Patient's discomfort | Discomfort related to the high flow oxygen therapy and related to the degree of humidification will be assessed by using a numerical rating scale from 1 (no discomfort) to 5 (maximum imaginable discomfort). Patients will be asked to rate their discomfort with the used device and discomfort symptoms will be determined for the dryness of the delivered oxygen (dryness of the mouth, throat, nose, difficulty to swallow and throat pain). | Patient's discomfort will be recorded at 1, 2, 3, 6, 12, 24 hours and every 24 hours after enrollment |