Clinical Trials Logo

Clinical Trial Summary

This pilot physiologic randomized cross-over study was designed to investigate if, in patients with hARF, a new device combining high-flow oxygen through nasal cannula (HFNC) and continuous positive airway pressure (CPAP) reduces the respiratory effort, as compared to HFNC and CPAP alone (first outcome). Furthermore, the diaphragm activation, as assessed with ultrasound, gas exchange and patient's comfort among different settings will be assessed (secondary outcomes).


Clinical Trial Description

Around 30% of patients admitted to the Intensive Care Unit (ICU) are affected by hypoxemic Acute Respiratory Failure (hARF). The primary supportive treatment in hypoxemic patients is oxygen therapy, which is commonly delivered through nasal prongs or masks. New devices, able to deliver high-flow gas through a nasal cannula (HFNC), have been recently made available. HFNC delivers heated and humidified gas up to 60 L/min, with a fraction of inspired oxygen (FiO2) ranging from 0.21 to 1, via a wide bore soft nasal prong. Warming and humidification of the inspired gas prevent the adverse effects of cool dry gases on the airway epithelium and facilitate expectoration. HFNC also washes out exhaled carbon dioxide (CO2) from the pharyngeal dead space. HFNC has been shown an effective means to deliver oxygen therapy in many clinical conditions. In healthy subject during spontaneous unassisted breathing, end-expiratory pharyngeal pressure is about 0.3 and 0.8 cmH2O, with open and closed mouth, respectively. Compared to unassisted spontaneous breathing, HFNC generates greater pharyngeal pressure during expiration, while in the course of inspiration it drops to zero, which limits the effectiveness of HFNC in patients with lung edema and/or collapse. By recruiting lung atelectatic regions, reducing venous admixture and decreasing the inspiratory effort, continuous positive airway pressure (CPAP) is likely more effective in these instances. Compared to noninvasive ventilation by application of an inspiratory pressure support, CPAP offers several advantages, which include ease of use and lack of patient-ventilator asynchrony. CPAP may be applied either through mask or helmet. This latter is better tolerated than facial masks and allows more prolonged continuous CPAP application. When applying CPAP by helmet, however, heating and humidification of the inhaled gas is problematic because of condensation of water inside the interface, so called "fog effect". Moreover, in patients receiving CPAP by helmet some re-breathing occurs. To overcome these limitations and combine the beneficial effects of HFNC and CPAP, the investigators designed a new device combining HFNC and helmet CPAP. Recently, this combination was shown to be capable to provide a stable CPAP and effective CO2 washout from the upper airways with negligible CO2 re-breathing. Nonetheless, because of the complex interplay between CPAP and HFNC, the amount of truly applied airway pressure, diaphragm function and temperature inside the helmet might be affected to some extent. In 14 adult healthy volunteers, we found that adding HFNC to CPAP (as referenced to CPAP), 1) did not importantly alter either the pre-set airway pressure during inspiration or temperature inside the helmet; 2) increased expiratory airway pressure proportionally to the flow administered by HFNC, but to a lower extent than HFNC alone (as referenced to spontaneous breathing); 3) determined only slight modifications of the respiratory drive (as assessed through diaphragm ultrasound), compared to CPAP alone, 4) did not cause "fog effect" inside the helmet and 5) did not worsen comfort. We therefore suggested that adding heated humidified air through nasal cannula at a flow of 30 L/min during CPAP would probably be the best setting to be applied in patients with hypoxemic acute respiratory failure. In patients with hARF, the use of noninvasive respiratory support (CPAP and non-invasive ventilation) is still debated. Patients receiving oxygen therapy, HFNC or CPAP/NIV maintain spontaneous breathing, which allows avoidance of sedation, thus limiting diaphragm dysfunction and delirium, permits easier mobilisation and prevents infections and ICU-acquired weakness. However, the maintenance of spontaneous breathing in patients with damaged lungs and high respiratory drive may result in global/regional pressure/volume changes possibly aggravating initial lung injury. This condition has been defined as patient self-inflicted lung injury (P-SILI). Indeed, respiratory drive is increased in patients with hARF. The high respiratory effort is one of the major determinants of increased transpulmonary pressure (Pl), which is the pressure acting across the lung. Pl represents the pressure alveoli are exposed to, and is considered among the most important determinants of P-SILI. Therefore, the reduction of Pl, across a decrease of the respiratory effort, might be advantageous in patients with hARF. Investigators have therefore designed this pilot physiologic randomized cross-over study to investigate if, in patients with hARF, HFNC+CPAP reduces the respiratory effort, as compared to HFNC and CPAP (first outcome). Furthermore, we will assess the diaphragm activation, as assessed with ultrasound, gas exchange and patient's comfort among different settings (secondary outcomes). ;


Study Design


Related Conditions & MeSH terms


NCT number NCT04619667
Study type Interventional
Source University Magna Graecia
Contact Federico Longhini, MD
Phone 00393475395967
Email longhini.federico@gmail.com
Status Not yet recruiting
Phase N/A
Start date December 1, 2020
Completion date December 31, 2021

See also
  Status Clinical Trial Phase
Recruiting NCT05144633 - Blue Protocol and Eko Artificial Intelligence Are Best (BEA-BEST)
Completed NCT04534569 - Expert Panel Statement for the Respiratory Management of COVID-19 Related Acute Respiratory Failure (C-ARF)
Recruiting NCT03021902 - Nutrition and Exercise in Critical Illness Phase 2
Completed NCT02902146 - Bougie Use in Emergency Airway Management N/A
Completed NCT02901158 - Esophageal Manometry in Mechanically Ventilated Patients
Completed NCT02236559 - High Flow Therapy for the Treatment of Respiratory Failure in the ED N/A
Recruiting NCT02056093 - Comparison of Proportional Assist Ventilation And Neurally Adjusted Ventilator Assist N/A
Not yet recruiting NCT01668368 - Goal Directed Mechanical Ventilation Aimed at Optimal Lung Compliance N/A
Terminated NCT01083277 - Variable Ventilation During Acute Respiratory Failure N/A
Completed NCT01462279 - Effect of Thiamine on Oxygen Utilization (VO2) in Critical Illness N/A
Completed NCT01114022 - Prevention Inhalation of Bacterial by Using Endotracheal Tube Balloon Polyvinyl Chloride or Polyurethane N/A
Active, not recruiting NCT01058421 - Treatment of Critical Illness Polyneuromyopathy Phase 2
Completed NCT00252616 - Timing of Target Enteral Feeding in the Mechanically Ventilated Patient Phase 2/Phase 3
Recruiting NCT04098094 - Outcomes of RV Dysfunction in Acute Exacerbation of Chronic Respiratory Diseases
Recruiting NCT06051292 - Decremental Esophageal Catheter Filling Volume Titration For Transpulmonary Pressure Measurement N/A
Completed NCT04601090 - Survival Rates and Longterm Outcomes After COVID-19
Recruiting NCT05423301 - Global Physiotherapy in ICU Patients With High Risk Extubation Failure N/A
Completed NCT02447692 - Proportional Assist Ventilation for Minimizing the Duration of Mechanical Ventilation: The PROMIZING Study N/A
Completed NCT04016480 - HFNC During Bronchoscopy for Bronchoalveolar Lavage N/A
Completed NCT04507425 - High Flow Nasal Cannula With Noninvasive Ventilation N/A