Clinical trial NCT02943863: Regional Ventilation During High Flow Nasal Cannula and Conventional Nasal Cannula in Patients With Hypoxia
Official title: Comparison of Regional Ventilation Pattern During High Flow Nasal Cannula Between Conventional Low Flow System Nasal Cannula in Patients With Mild to Moderate Hypoxia
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Hypoxia
Oxygen Therapy
High Flow Nasal Cannula
Ventilation
Lead sponsor: Asan Medical Center
Sponsor class: OTHER
Collaborators: name: Ministry of Trade, Industry & Energy, Republic of Korea
First posted: 2016-10-25
Enrollment: 24
Sex: ALL
Minimum age (years): 20
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: TREATMENT

Brief summary: High-flow nasal cannula (HFNC) that uses heated and humidified oxygen was recently introduced for bedside care. It has been shown to be associated with reduced risks of tracheal intubation rates and mortality in adult hypoxic patients.

The mechanisms of the effects of HFNC are thought to be related to the favorable effects of the heated and humidified gas, the high-flow rate used to minimize the entrainment of room air, and an increase in the ventilation efficiency, including the elimination of nasopharyngeal dead space, positive end-expiratory pressure (PEEP) effects, and improvements in paradoxical abdominal movement. Regarding the effects on lung volume, global ventilation in the lungs increases during HFNC, which is thought to attribute to PEEP effects. However, how regional ventilation is affected during HFNC in comparison with conventional NC remains unknown.

Because PEEP in mechanically ventilated patients improves the regional homogeneity of ventilation, investigators postulated that HFNC via PEEP effects would result in more homogeneous regional distributions in the ventilation changes. Investigators therefore assessed global and regional ventilation in patients with hypoxia receiving care via HFNC using electric impedance tomography and compared these results with conventional nasal cannula.


Eligibility criteria: Inclusion Criteria:

* Age \>20 years
* Subjective dyspnea in room air
* SaO2\< 90% in room air
* Oxygen requirement for nasal cannula \< 6 L/m

Exclusion Criteria:

* Unstable vital signs

  * SBP \<90 mmHg
  * DBP \< 60 mmHg
  * Heart rate \> 120 bpm
  * Respiratory rate \> 30 bpm
  * Persistent dyspnea under oxygen therapy using NC
* Severe hypoxia

  * PaO2/FiO2\< 200 mmHg
* Unable to cooperate

  * Delirium
  * Reduced cognitive function

Primary outcomes:
measure: Tidal variation
timeFrame: Twenty minutes after each oxygen therapy. (At the end of each oxygen therapy)
Secondary outcomes:
measure: Oxygen saturation
timeFrame: Twenty minutes after each oxygen therapy. (At the end of each oxygen therapy)
measure: Respiration Rate
timeFrame: Twenty minutes after each oxygen therapy. (At the end of each oxygen therapy)
measure: Subjective comfort
timeFrame: Twenty minutes after each oxygen therapy. (At the end of each oxygen therapy)
Other outcomes:
Locations:
Study officials:
affiliation: Pulmonary and Critical Care Medicine, Asan Medical Center, College of Medicine, University of Ulsan
name: Chae-Man Lim, MD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Spoletini G, Alotaibi M, Blasi F, Hill NS. Heated Humidified High-Flow Nasal Oxygen in Adults: Mechanisms of Action and Clinical Implications. Chest. 2015 Jul;148(1):253-261. doi: 10.1378/chest.14-2871.
citation: Riera J, Perez P, Cortes J, Roca O, Masclans JR, Rello J. Effect of high-flow nasal cannula and body position on end-expiratory lung volume: a cohort study using electrical impedance tomography. Respir Care. 2013 Apr;58(4):589-96. doi: 10.4187/respcare.02086.
citation: Hsu CF, Cheng JS, Lin WC, Ko YF, Cheng KS, Lin SH, Chen CW. Electrical impedance tomography monitoring in acute respiratory distress syndrome patients with mechanical ventilation during prolonged positive end-expiratory pressure adjustments. J Formos Med Assoc. 2016 Mar;115(3):195-202. doi: 10.1016/j.jfma.2015.03.001. Epub 2015 Apr 3.
citation: Lee DH, Kim EY, Seo GJ, Suh HJ, Huh JW, Hong SB, Koh Y, Lim CM. Global and Regional Ventilation during High Flow Nasal Cannula in Patients with Hypoxia. Acute Crit Care. 2018 Feb;33(1):7-15. doi: 10.4266/acc.2017.00507. Epub 2018 Jan 22.