<clinical_study>
  <!-- This xml conforms to an XML Schema at:
    https://clinicaltrials.gov/ct2/html/images/info/public.xsd -->
  <required_header>
    <download_date>ClinicalTrials.gov processed this data on September 20, 2023</download_date>
    <link_text>Link to the current ClinicalTrials.gov record.</link_text>
    <url>https://clinicaltrials.gov/ct2/show/NCT03788304</url>
  </required_header>
  <id_info>
    <org_study_id>High flow nasal cannula</org_study_id>
    <nct_id>NCT03788304</nct_id>
  </id_info>
  <brief_title>High Flow Nasal Cannula Versus Non-invasive Ventilation in Prevention of Escalation to Invasive Mechanical Ventilation in Patients With Acute Hypoxemic Respiratory Failure</brief_title>
  <official_title>High Flow Nasal Cannula Versus Non-invasive Ventilation in Prevention of Escalation to Invasive Mechanical Ventilation in Patients With Acute Hypoxemic Respiratory Failure</official_title>
  <sponsors>
    <lead_sponsor>
      <agency>Assiut University</agency>
      <agency_class>Other</agency_class>
    </lead_sponsor>
  </sponsors>
  <source>Assiut University</source>
  <oversight_info>
    <has_dmc>No</has_dmc>
    <is_fda_regulated_drug>No</is_fda_regulated_drug>
    <is_fda_regulated_device>No</is_fda_regulated_device>
  </oversight_info>
  <brief_summary>
    <textblock>
      Oxygen therapy is first-line treatment in the management of acute respiratory failure (ARF).&#xD;
      Different oxygen devices have become available over recent decades, such as low-flow systems&#xD;
      (nasal cannula, simple facemask, non-rebreathing reservoir mask) and high-flow systems&#xD;
      (Venturi mask) . Since the 90's, non-invasive ventilation (NIV) has been largely used with&#xD;
      strong level of evidence in cardiogenic pulmonary edema and chronic obstructive pulmonary&#xD;
      disease (COPD) exacerbation. NIV improves gas exchange and reduces inspiratory effort through&#xD;
      positive pressure. However, good tolerance to NIV is sometimes difficult to achieve due to&#xD;
      frequent leaks around the mask, possibly leading to patient-ventilator asynchrony and even to&#xD;
      intubation . High-flow nasal oxygen therapy (HFNO) is an innovative high-flow system that&#xD;
      allows for delivering up to 60 liters\ min of heated and fully humidified gas with a FIO2&#xD;
      ranging between 21% and 100% . It is a new method of respiratory support in adults that has&#xD;
      been used in neonatal ARF for some years. The reason this study is necessary is because, even&#xD;
      though NIV has been demonstrated to prevent endotracheal intubation (and its associated&#xD;
      complications) in a broad range of ARF patients, HFNC has been proposed to have the same&#xD;
      effect as NIV while being easier tolerated, more physiological , allowing patients to&#xD;
      continue to talk, eat and drink through mouth while on HFNC&#xD;
    </textblock>
  </brief_summary>
  <detailed_description>
    <textblock>
      Oxygen therapy is the first-line treatment in management of acute respiratory failure (ARF).&#xD;
      Different oxygen delivery devices have become available over recent decades, either low-flow&#xD;
      systems (nasal cannula, simple facemask, non-rebreathing reservoir mask) or high-flow systems&#xD;
      (Venturi mask) . The choice of a specific device in management of ARF is based on the&#xD;
      severity of hypoxemia, the underlying mechanisms, the patient's breathing pattern and&#xD;
      tolerance .&#xD;
&#xD;
      Critically ill patients often require high-flow devices to meet their oxygen needs .&#xD;
      Tachypneic patients with ARF, have a peak inspiratory flow rate that is usually high and&#xD;
      often exceeds the oxygen flow delivered by the traditional oxygen devices . Using&#xD;
      conventional devices, oxygen flow is limited to no more than 15 L/min. Meanwhile, the&#xD;
      required inspiratory flow for patients with respiratory failure varies widely in a range from&#xD;
      30 to120 L/min. The difference between patient inspiratory flow and delivered flow is large&#xD;
      with conventional oxygen devices leading to patient discomfort . Moreover; high respiratory&#xD;
      rate can generate significant entrainment of room air in the mask and dilution of the&#xD;
      inspired oxygen with an insufficient oxygen concentration. The suboptimal humidification of&#xD;
      the inhaled oxygen provided by standard bubble humidifiers and the limited and unknown&#xD;
      inspiratory oxygen fraction (FIO2) delivery are additional drawbacks of these devices .&#xD;
&#xD;
      Since the 90's, noninvasive ventilation (NIV) has been largely used with strong level of&#xD;
      evidence in cardiogenic pulmonary edema and chronic obstructive pulmonary disease (COPD)&#xD;
      exacerbation. NIV improves gas exchange and reduces inspiratory effort through positive&#xD;
      pressure. However, good tolerance to NIV is sometimes difficult to achieve due to frequent&#xD;
      leaks around the mask, possibly leading to patient-ventilator asynchrony and even to&#xD;
      intubation. It may have other deleterious effects such as delayed intubation by masking signs&#xD;
      of respiratory distress, or barotrauma by the high tidal volume potentially generated under&#xD;
      positive pressure .&#xD;
&#xD;
      To ensure good results, an appropriate interface is more important than the ventilation mode&#xD;
      . Oronasal masks, nasal masks, and hoods are most commonly used for NIV. Oronasal masks are&#xD;
      usually tried first because they ensure the effects of NIV better than other interfaces.&#xD;
      Unfortunately, it is not comfortable, and many patients find it hard to tolerate. It is also&#xD;
      associated with a relatively high incidence of air leakage. Also, skin lesions at the nose&#xD;
      induced by long-term use of this device may result in frequent treatment interruptions and&#xD;
      discontinuation.&#xD;
&#xD;
      High-flow nasal oxygen therapy (HFNO) is an innovative high-flow system that allows for&#xD;
      delivering up to 60 liters/ min of heated and fully humidified gas with a FIO2 ranging&#xD;
      between 21% and 100% [.&#xD;
&#xD;
        -  HFNO delivery systems: main technical characteristics: - The administration of HFNO&#xD;
           requires the following: high pressure sources of oxygen and air, an air-oxygen blender&#xD;
           or a high-flow 'Venturi' system (which permits delivery of an accurate FIO2 between 21%&#xD;
           and 100%), a humidifying and heating system for conditioning the gas to optimal&#xD;
           temperature (37 ºC) and humidity (44mg H2O/ liters), a sterile water reservoir, a&#xD;
           non-condensing circuitry, and an interface . The two most widely marketed HFNO systems&#xD;
           are the Precision Flow by Vapotherm and Optiflow by Fisher &amp; Pykel Healthcare Ltd.&#xD;
&#xD;
        -  Physiological effects of HFNC: - Gas from an air/oxygen blender that can generate a&#xD;
           total flow of up to 60 L/min is heated and humidified with an active humidifier and&#xD;
           subsequently delivered through a heated circuit. High flow of adequately heated and&#xD;
           humidified gas is considered to have a number of physiological effects&#xD;
&#xD;
             1. Washout of nasopharyngeal dead space: Washout of upper airway dead space from the&#xD;
                delivery of a large amount of oxygen can improve the efficiency of ventilation and&#xD;
                enhance oxygen delivery . HFNC is the only noninvasive respiratory support that&#xD;
                does not increase dead space. With an oxygen mask, especially at low flow, carbon&#xD;
                dioxide is rebreathed .&#xD;
&#xD;
             2. Warming and humidification of secretions: Warming of inspired oxygen and heating it&#xD;
                to core temperature is more effective at high flow rates (typically &gt;40 L/minute)&#xD;
                than low flow rates. Thus, HFNC is better at heating and humidifying inspired&#xD;
                oxygen than conventional high-flow systems such as Venturi masks or nonrebreathers&#xD;
                (flow rate typically 10 to 15 L/minute) or low-flow systems (flow rates typically&#xD;
                &lt;10 L/minute) . Increased humidification results in increased water content in&#xD;
                mucous, which can facilitate secretion removal and may also decrease the work of&#xD;
                breathing and avoid airway desiccation and epithelial injury&#xD;
&#xD;
             3. Continuous positive airway pressure (CPAP) effect: Several studies in adults have&#xD;
                shown that, similar to infants and neonates, HFNC increases nasopharyngeal airway&#xD;
                pressure that peaks at the end of expiration (ie, &quot;PEEP effect&quot;) . This &quot;PEEP&#xD;
                effect&quot; can potentially unload auto-PEEP, decrease work of breathing, and enhance&#xD;
                oxygenation in patients with alveolar filling diseases such as congestive heart&#xD;
                failure or acute respiratory distress syndrome (ARDS). As flow increases,&#xD;
                nasopharyngeal pressure increases (ie, a dose effect) . The CPAP effect is greatest&#xD;
                with the mouth closed. In general, every increase of 10 L/minute of flow yields&#xD;
                approximately 0.7 cm H2O of airway pressure when the mouth is closed and 0.35 cm of&#xD;
                H2O when the mouth is open.&#xD;
&#xD;
             4. Small pliable nasal prongs: HFNC nasal prongs are generally soft and pliable.&#xD;
                Consequently, several studies have reported improved patient comfort with HFNC when&#xD;
                compared with conventional low-flow oxygen delivered through nasal cannula or&#xD;
                high-flow oxygen delivered through a face mask .&#xD;
&#xD;
             5. High flow rates: High flow rates result in minimal entrainment of room air when&#xD;
                HFNC is used; this results in more accurate delivery of oxygen. Patients in&#xD;
                respiratory distress generate high inspiratory flow rates that exceed flow rates of&#xD;
                standard oxygen equipment, resulting in entrainment of room air and a reduction in&#xD;
                the delivery of the set FIO2. The rate of flow in HFNC generally exceeds that of&#xD;
                the patient, entraining very little room air and resulting in an FIO2 that is more&#xD;
                reliably delivered . High flow rates have also been shown to result in an improved&#xD;
                breathing pattern by increasing tidal volume and decreasing respiratory rate .&#xD;
&#xD;
             6. Reduction of work of breathing: The HFNO system may significantly reduce the energy&#xD;
                requirement (metabolic work) associated with gas conditioning. By providing high&#xD;
                gas flows, HFNO reduces the resistance of the upper airway and then decreases the&#xD;
                resistive breathing effort .&#xD;
    </textblock>
  </detailed_description>
  <overall_status>Unknown status</overall_status>
  <last_known_status>Recruiting</last_known_status>
  <start_date type="Actual">May 1, 2019</start_date>
  <completion_date type="Anticipated">December 1, 2020</completion_date>
  <primary_completion_date type="Anticipated">April 30, 2020</primary_completion_date>
  <phase>N/A</phase>
  <study_type>Interventional</study_type>
  <has_expanded_access>No</has_expanded_access>
  <study_design_info>
    <allocation>Randomized</allocation>
    <intervention_model>Parallel Assignment</intervention_model>
    <intervention_model_description>patients with will be randomly enrolled to either non invasive group or HFNC group and improvement and patient satisfaction will be assessed</intervention_model_description>
    <primary_purpose>Treatment</primary_purpose>
    <masking>Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)</masking>
    <masking_description>Neither the participant , care provider , the investigator nor the outcome assessor will select patients in both groups , see results of other patients till the end of the study or informed by literature opinion in this intervention</masking_description>
  </study_design_info>
  <primary_outcome>
    <measure>Endotracheal intubation rate.</measure>
    <time_frame>one week</time_frame>
    <description>needs escalation to invasive mechanical ventilation</description>
  </primary_outcome>
  <secondary_outcome>
    <measure>In hospital mortality.</measure>
    <time_frame>one week</time_frame>
    <description>death</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>length of hospital stay</measure>
    <time_frame>one week</time_frame>
    <description>hospital coast</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>duration of ICU stay</measure>
    <time_frame>one week</time_frame>
    <description>icu occupancy</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>duration of intervention</measure>
    <time_frame>one week</time_frame>
    <description>need ventilatory support</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>development of complications</measure>
    <time_frame>one week</time_frame>
    <description>due to devices</description>
  </secondary_outcome>
  <number_of_arms>2</number_of_arms>
  <enrollment type="Anticipated">100</enrollment>
  <condition>Respiratory Failure</condition>
  <arm_group>
    <arm_group_label>Non invasive ventilation</arm_group_label>
    <arm_group_type>Active Comparator</arm_group_type>
    <description>Respiratory assistance is provided by a NIV either Puritan Bennet 840 , Engström Carestation or Hamilton-G5 , will be used for conventional non-invasive ventilation via an oronasal mask. Settings will be adjusted based on the clinical assessment of the respiratory therapist . Initial setting includes: -&#xD;
Positive End Expiratory Pressure (PEEP): 5 cmH2O.&#xD;
Pressure support (PS): 12-20 cmH2O.&#xD;
FiO2 will be adjusted to achieve a SpO2 at least 95%</description>
  </arm_group>
  <arm_group>
    <arm_group_label>High flow nasal cannula</arm_group_label>
    <arm_group_type>Experimental</arm_group_type>
    <description>High flow nasal cannula consists of an apparatus that allows adjustable FiO2 from 21 to 100% and delivers a modified gas flow up to 60 l/ min .&#xD;
will be set with: -&#xD;
Temperature at 37°C or 34°C&#xD;
Flow rate 30: 50 L/min.&#xD;
FiO2 will be adjusted to achieve a SpO2 at least 95%</description>
  </arm_group>
  <intervention>
    <intervention_type>Device</intervention_type>
    <intervention_name>non-invasive ventilation</intervention_name>
    <description>conventional NIV</description>
    <arm_group_label>Non invasive ventilation</arm_group_label>
  </intervention>
  <intervention>
    <intervention_type>Device</intervention_type>
    <intervention_name>high flow nasal cannula</intervention_name>
    <description>HFNC ventilation</description>
    <arm_group_label>High flow nasal cannula</arm_group_label>
  </intervention>
  <eligibility>
    <criteria>
      <textblock>
        Inclusion Criteria:&#xD;
&#xD;
          -  Participants admitted to the RICU with acute hypoxemic respiratory failure requiring&#xD;
             NIV support with the following criteria:&#xD;
&#xD;
               1. RR&gt; 25 breath/minute&#xD;
&#xD;
               2. Use of accessory muscles of respiration, paradoxical breathing, thoracoabdominal&#xD;
                  asynchrony.&#xD;
&#xD;
               3. Hypoxemia evidenced by PaO2 / FiO2 ratio &lt;300&#xD;
&#xD;
        Exclusion Criteria:&#xD;
&#xD;
        Patients who have any of the following:&#xD;
&#xD;
        I. Indication for emergency endotracheal intubation. II. HR &lt;50 beat\minute with decreased&#xD;
        level of consciousness III. Persistent hemodynamic instability with&#xD;
&#xD;
          -  Systolic blood pressure &lt;90 mmHg after infusing a bolus of crystalloid solution at a&#xD;
             dose of 30 ml / kg&#xD;
&#xD;
          -  life-threatening arrhythmia. IV. Undrained pneumothorax or Pneumothorax with&#xD;
             persistent air leak. V. Extensive facial trauma or burn VI. Refusal to participate.&#xD;
             VII. Usual long-term treatment with NIV for chronic disease VIII. Altered mental&#xD;
             status with decreased consciousness and/or evidence of inability to understand .&#xD;
&#xD;
        IX. Tracheotomy or other upper airway disorders X. Active upper gastrointestinal bleeding&#xD;
      </textblock>
    </criteria>
    <gender>All</gender>
    <minimum_age>18 Years</minimum_age>
    <maximum_age>N/A</maximum_age>
    <healthy_volunteers>No</healthy_volunteers>
  </eligibility>
  <overall_official>
    <last_name>Mohamed F Adam, lecturer</last_name>
    <role>Principal Investigator</role>
    <affiliation>Assiut University</affiliation>
  </overall_official>
  <overall_official>
    <last_name>Manal A El-Khawaga, lecturer</last_name>
    <role>Principal Investigator</role>
    <affiliation>Assiut University</affiliation>
  </overall_official>
  <overall_contact>
    <last_name>Entsar H mohamed, MD</last_name>
    <phone>+201019968106</phone>
    <email>dr.entsar_hsanen@yahoo.com</email>
  </overall_contact>
  <overall_contact_backup>
    <last_name>Gamal M Rabie, professor</last_name>
    <phone>+201155213224</phone>
    <email>Gamalagmy135@gmail.com</email>
  </overall_contact_backup>
  <location>
    <facility>
      <name>Assiut University hospital</name>
      <address>
        <city>Assiut</city>
        <zip>assiut University 71515</zip>
        <country>Egypt</country>
      </address>
    </facility>
    <status>Recruiting</status>
    <contact>
      <last_name>Entsar H mohamed, master</last_name>
      <phone>01019968106</phone>
      <email>dr.entsar_hsanen@yahoo.com</email>
    </contact>
    <contact_backup>
      <last_name>Gamal M Rabie, MD</last_name>
      <phone>01155213224</phone>
      <email>Gamalagmy135@gmail.com</email>
    </contact_backup>
  </location>
  <location_countries>
    <country>Egypt</country>
  </location_countries>
  <reference>
    <citation>1-Renda, T., Corrado, A., Iskandar, G., et al. High-flow nasal oxygen therapy in intensive care and anaesthesia . British journal of anaesthesia 2018 , 120(1), 18-27 2-Kallstrom TJ. AARC clinical practice guideline: oxygen therapy for adults in the acute care facility: 2002 revision and update. Respir Care 2002; 47: 717-20. 3-O'Driscoll BR, Howard LS, Davison AG, on behalf of the British Thoracic Society. BTS guideline for emergency oxygen use in adult patients. Thorax 2008; 63: 1-68. 4-Sim MA, Dean P, Kinsella J, et al. Performance of oxygen delivery devices when the breathing pattern of respiratory failure is simulated. Anaesthesia 2008; 63: 938-40 5-Nishimura, M. High-flow nasal cannula oxygen therapy in adults: physiological benefits, indication, clinical benefits, and adverse effects. Respiratory Care 2016, 61(4), 529-541.</citation>
  </reference>
  <verification_date>October 2019</verification_date>
  <study_first_submitted>December 20, 2018</study_first_submitted>
  <study_first_submitted_qc>December 26, 2018</study_first_submitted_qc>
  <study_first_posted type="Actual">December 27, 2018</study_first_posted>
  <last_update_submitted>October 17, 2019</last_update_submitted>
  <last_update_submitted_qc>October 17, 2019</last_update_submitted_qc>
  <last_update_posted type="Actual">October 21, 2019</last_update_posted>
  <responsible_party>
    <responsible_party_type>Principal Investigator</responsible_party_type>
    <investigator_affiliation>Assiut University</investigator_affiliation>
    <investigator_full_name>Entsar Hsanen Mohamed</investigator_full_name>
    <investigator_title>principle investigator</investigator_title>
  </responsible_party>
  <condition_browse>
    <!-- CAUTION:  The following MeSH terms are assigned with an imperfect algorithm            -->
    <mesh_term>Respiratory Insufficiency</mesh_term>
  </condition_browse>
  <!-- Results have not yet been posted for this study                                          -->
</clinical_study>


download date: ClinicalTrials.gov processed this data on September 20, 2023
link text: Link to the current ClinicalTrials.gov record.
url: https://clinicaltrials.gov/ct2/show/NCT03788304
org study id: High flow nasal cannula
nct id: NCT03788304
lead sponsor: 
has dmc: No
is fda regulated drug: No
is fda regulated device: No
Oxygen therapy is first-line treatment in the management of acute respiratory failure (ARF).
      Different oxygen devices have become available over recent decades, such as low-flow systems
      (nasal cannula, simple facemask, non-rebreathing reservoir mask) and high-flow systems
      (Venturi mask) . Since the 90's, non-invasive ventilation (NIV) has been largely used with
      strong level of evidence in cardiogenic pulmonary edema and chronic obstructive pulmonary
      disease (COPD) exacerbation. NIV improves gas exchange and reduces inspiratory effort through
      positive pressure. However, good tolerance to NIV is sometimes difficult to achieve due to
      frequent leaks around the mask, possibly leading to patient-ventilator asynchrony and even to
      intubation . High-flow nasal oxygen therapy (HFNO) is an innovative high-flow system that
      allows for delivering up to 60 liters\ min of heated and fully humidified gas with a FIO2
      ranging between 21% and 100% . It is a new method of respiratory support in adults that has
      been used in neonatal ARF for some years. The reason this study is necessary is because, even
      though NIV has been demonstrated to prevent endotracheal intubation (and its associated
      complications) in a broad range of ARF patients, HFNC has been proposed to have the same
      effect as NIV while being easier tolerated, more physiological , allowing patients to
      continue to talk, eat and drink through mouth while on HFNC
Oxygen therapy is the first-line treatment in management of acute respiratory failure (ARF).
      Different oxygen delivery devices have become available over recent decades, either low-flow
      systems (nasal cannula, simple facemask, non-rebreathing reservoir mask) or high-flow systems
      (Venturi mask) . The choice of a specific device in management of ARF is based on the
      severity of hypoxemia, the underlying mechanisms, the patient's breathing pattern and
      tolerance .

      Critically ill patients often require high-flow devices to meet their oxygen needs .
      Tachypneic patients with ARF, have a peak inspiratory flow rate that is usually high and
      often exceeds the oxygen flow delivered by the traditional oxygen devices . Using
      conventional devices, oxygen flow is limited to no more than 15 L/min. Meanwhile, the
      required inspiratory flow for patients with respiratory failure varies widely in a range from
      30 to120 L/min. The difference between patient inspiratory flow and delivered flow is large
      with conventional oxygen devices leading to patient discomfort . Moreover; high respiratory
      rate can generate significant entrainment of room air in the mask and dilution of the
      inspired oxygen with an insufficient oxygen concentration. The suboptimal humidification of
      the inhaled oxygen provided by standard bubble humidifiers and the limited and unknown
      inspiratory oxygen fraction (FIO2) delivery are additional drawbacks of these devices .

      Since the 90's, noninvasive ventilation (NIV) has been largely used with strong level of
      evidence in cardiogenic pulmonary edema and chronic obstructive pulmonary disease (COPD)
      exacerbation. NIV improves gas exchange and reduces inspiratory effort through positive
      pressure. However, good tolerance to NIV is sometimes difficult to achieve due to frequent
      leaks around the mask, possibly leading to patient-ventilator asynchrony and even to
      intubation. It may have other deleterious effects such as delayed intubation by masking signs
      of respiratory distress, or barotrauma by the high tidal volume potentially generated under
      positive pressure .

      To ensure good results, an appropriate interface is more important than the ventilation mode
      . Oronasal masks, nasal masks, and hoods are most commonly used for NIV. Oronasal masks are
      usually tried first because they ensure the effects of NIV better than other interfaces.
      Unfortunately, it is not comfortable, and many patients find it hard to tolerate. It is also
      associated with a relatively high incidence of air leakage. Also, skin lesions at the nose
      induced by long-term use of this device may result in frequent treatment interruptions and
      discontinuation.

      High-flow nasal oxygen therapy (HFNO) is an innovative high-flow system that allows for
      delivering up to 60 liters/ min of heated and fully humidified gas with a FIO2 ranging
      between 21% and 100% [.

        -  HFNO delivery systems: main technical characteristics: - The administration of HFNO
           requires the following: high pressure sources of oxygen and air, an air-oxygen blender
           or a high-flow 'Venturi' system (which permits delivery of an accurate FIO2 between 21%
           and 100%), a humidifying and heating system for conditioning the gas to optimal
           temperature (37 ºC) and humidity (44mg H2O/ liters), a sterile water reservoir, a
           non-condensing circuitry, and an interface . The two most widely marketed HFNO systems
           are the Precision Flow by Vapotherm and Optiflow by Fisher & Pykel Healthcare Ltd.

        -  Physiological effects of HFNC: - Gas from an air/oxygen blender that can generate a
           total flow of up to 60 L/min is heated and humidified with an active humidifier and
           subsequently delivered through a heated circuit. High flow of adequately heated and
           humidified gas is considered to have a number of physiological effects

             1. Washout of nasopharyngeal dead space: Washout of upper airway dead space from the
                delivery of a large amount of oxygen can improve the efficiency of ventilation and
                enhance oxygen delivery . HFNC is the only noninvasive respiratory support that
                does not increase dead space. With an oxygen mask, especially at low flow, carbon
                dioxide is rebreathed .

             2. Warming and humidification of secretions: Warming of inspired oxygen and heating it
                to core temperature is more effective at high flow rates (typically >40 L/minute)
                than low flow rates. Thus, HFNC is better at heating and humidifying inspired
                oxygen than conventional high-flow systems such as Venturi masks or nonrebreathers
                (flow rate typically 10 to 15 L/minute) or low-flow systems (flow rates typically
                <10 L/minute) . Increased humidification results in increased water content in
                mucous, which can facilitate secretion removal and may also decrease the work of
                breathing and avoid airway desiccation and epithelial injury

             3. Continuous positive airway pressure (CPAP) effect: Several studies in adults have
                shown that, similar to infants and neonates, HFNC increases nasopharyngeal airway
                pressure that peaks at the end of expiration (ie, "PEEP effect") . This "PEEP
                effect" can potentially unload auto-PEEP, decrease work of breathing, and enhance
                oxygenation in patients with alveolar filling diseases such as congestive heart
                failure or acute respiratory distress syndrome (ARDS). As flow increases,
                nasopharyngeal pressure increases (ie, a dose effect) . The CPAP effect is greatest
                with the mouth closed. In general, every increase of 10 L/minute of flow yields
                approximately 0.7 cm H2O of airway pressure when the mouth is closed and 0.35 cm of
                H2O when the mouth is open.

             4. Small pliable nasal prongs: HFNC nasal prongs are generally soft and pliable.
                Consequently, several studies have reported improved patient comfort with HFNC when
                compared with conventional low-flow oxygen delivered through nasal cannula or
                high-flow oxygen delivered through a face mask .

             5. High flow rates: High flow rates result in minimal entrainment of room air when
                HFNC is used; this results in more accurate delivery of oxygen. Patients in
                respiratory distress generate high inspiratory flow rates that exceed flow rates of
                standard oxygen equipment, resulting in entrainment of room air and a reduction in
                the delivery of the set FIO2. The rate of flow in HFNC generally exceeds that of
                the patient, entraining very little room air and resulting in an FIO2 that is more
                reliably delivered . High flow rates have also been shown to result in an improved
                breathing pattern by increasing tidal volume and decreasing respiratory rate .

             6. Reduction of work of breathing: The HFNO system may significantly reduce the energy
                requirement (metabolic work) associated with gas conditioning. By providing high
                gas flows, HFNO reduces the resistance of the upper airway and then decreases the
                resistive breathing effort .
allocation: Randomized
intervention model: Parallel Assignment
intervention model description: patients with will be randomly enrolled to either non invasive group or HFNC group and improvement and patient satisfaction will be assessed
primary purpose: Treatment
masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
masking description: Neither the participant , care provider , the investigator nor the outcome assessor will select patients in both groups , see results of other patients till the end of the study or informed by literature opinion in this intervention
measure: Endotracheal intubation rate.
time frame: one week
description: needs escalation to invasive mechanical ventilation
measure: In hospital mortality.
time frame: one week
description: death
measure: length of hospital stay
time frame: one week
description: hospital coast
measure: duration of ICU stay
time frame: one week
description: icu occupancy
measure: duration of intervention
time frame: one week
description: need ventilatory support
measure: development of complications
time frame: one week
description: due to devices
arm group label: Non invasive ventilation
arm group type: Active Comparator
description: Respiratory assistance is provided by a NIV either Puritan Bennet 840 , Engström Carestation or Hamilton-G5 , will be used for conventional non-invasive ventilation via an oronasal mask. Settings will be adjusted based on the clinical assessment of the respiratory therapist . Initial setting includes: -
Positive End Expiratory Pressure (PEEP): 5 cmH2O.
Pressure support (PS): 12-20 cmH2O.
FiO2 will be adjusted to achieve a SpO2 at least 95%
arm group label: High flow nasal cannula
arm group type: Experimental
description: High flow nasal cannula consists of an apparatus that allows adjustable FiO2 from 21 to 100% and delivers a modified gas flow up to 60 l/ min .
will be set with: -
Temperature at 37°C or 34°C
Flow rate 30: 50 L/min.
FiO2 will be adjusted to achieve a SpO2 at least 95%
intervention type: Device
intervention name: non-invasive ventilation
description: conventional NIV
arm group label: Non invasive ventilation
intervention type: Device
intervention name: high flow nasal cannula
description: HFNC ventilation
arm group label: High flow nasal cannula
criteria: 
gender: All
minimum age: 18 Years
maximum age: N/A
healthy volunteers: No
last name: Mohamed F Adam, lecturer
role: Principal Investigator
affiliation: Assiut University
last name: Manal A El-Khawaga, lecturer
role: Principal Investigator
affiliation: Assiut University
last name: Entsar H mohamed, MD
phone: +201019968106
email: dr.entsar_hsanen@yahoo.com
last name: Gamal M Rabie, professor
phone: +201155213224
email: Gamalagmy135@gmail.com
facility: 
status: Recruiting
contact: 
contact backup: 
country: Egypt
citation: 1-Renda, T., Corrado, A., Iskandar, G., et al. High-flow nasal oxygen therapy in intensive care and anaesthesia . British journal of anaesthesia 2018 , 120(1), 18-27 2-Kallstrom TJ. AARC clinical practice guideline: oxygen therapy for adults in the acute care facility: 2002 revision and update. Respir Care 2002; 47: 717-20. 3-O'Driscoll BR, Howard LS, Davison AG, on behalf of the British Thoracic Society. BTS guideline for emergency oxygen use in adult patients. Thorax 2008; 63: 1-68. 4-Sim MA, Dean P, Kinsella J, et al. Performance of oxygen delivery devices when the breathing pattern of respiratory failure is simulated. Anaesthesia 2008; 63: 938-40 5-Nishimura, M. High-flow nasal cannula oxygen therapy in adults: physiological benefits, indication, clinical benefits, and adverse effects. Respiratory Care 2016, 61(4), 529-541.
responsible party type: Principal Investigator
investigator affiliation: Assiut University
investigator full name: Entsar Hsanen Mohamed
investigator title: principle investigator
mesh term: Respiratory Insufficiency