Sequential application of oxygen therapy via high-flow nasal cannula and noninvasive ventilation in acute respiratory failure: an observational pilot study.

The aim of this study was to evaluate the clinical efficacy of humidified oxygen via high-flow nasal cannula (HFNC) alternating with noninvasive ventilation (NIV) in acute hypoxemic respiratory failure (AHRF). We performed a prospective observational study in a 12-bed ICU of a university hospital. All subjects with a PaO2 /FIO2 of ≤300 mm Hg with standard mask oxygen and a breathing frequency of > 30 breaths/min or signs of respiratory distress were included and treated with HFNC first and then NIV. Ventilatory parameters, blood gases, and tolerance were recorded during 2 consecutive sessions of NIV and HFNC. Outcome was assessed after continuation of this noninvasive strategy. Twenty-eight subjects with AHRF were studied, including 23 (82%) with ARDS. Compared with standard oxygen therapy, PaO2 significantly increased from 83 (68-97) mm Hg to 108 (83-140) mm Hg using HFNC and to 125 (97-200) mm Hg using NIV (P<.01), whereas breathing frequency significantly decreased. HFNC was significantly better tolerated than NIV, with a lower score on the visual analog scale. The non-intubated subjects received HFNC for 75 (27-127) h and NIV for 23 (8-31) h. Intubation was required in 10 of 28 subjects (36%), including 8 of 23 subjects with ARDS (35%). After HFNC initiation, a breathing frequency of ≥30 breaths/min was an early factor associated with intubation. HFNC was better tolerated than NIV and allowed for significant improvement in oxygenation and tachypnea compared with standard oxygen therapy in subjects with AHRF, a large majority of whom had ARDS. Thus, HFNC may be used between NIV sessions to avoid marked impairment of oxygenation.

Frat JP ，Brugiere B ，Ragot S ，Chatellier D ，Veinstein A ，Goudet V ，Coudroy R ，Petitpas F ，Robert R ，Thille AW ，Girault C ... -  《-》

Use of High-Flow Nasal Cannula Oxygen Therapy in Subjects With ARDS: A 1-Year Observational Study.

Beneficial effects of high-flow nasal cannula (HFNC) oxygen on oxygenation and respiratory parameters have been reported in a small number of subjects with acute respiratory failure (ARF). We aimed to evaluate its effect in subjects with ARDS. This was an observational single-center study. Prospectively obtained data were retrospectively analyzed. All patients admitted over 1 y to a university hospital medicosurgical ICU were included. Classification was according to the highest ventilatory support required. HFNC indications were reviewed, and demographics, clinical characteristics, and course of subjects with ARDS according to intubation need were compared. Of 607 subjects admitted, 560 required ventilatory or oxygen support, among whom 180 received noninvasive ventilatory support. HFNC was used in 87 subjects and as first-line treatment in 51 subjects (29% of first-line noninvasively treated subjects), 45 of which had ARDS (PaO2 /FIO2 of 137 mm Hg; 22 men, 57.9 y of age). Pneumonia accounted for 82% of ARDS causes. The intubation rate in these subjects was 40%. Higher Simplified Acute Physiology Score II (SAPS II; 46 vs 29, P=.001), occurrence of additional organ failure (76% vs 26%, P=.002), mainly hemodynamic (50% vs 7%, P=.001) or neurological (22% vs 0, P=.01), and trends toward lower PaO2 /FIO2 and higher breathing frequency after HFNC initiation were evidenced in subjects who failed HFNC. Higher SAPS II scores were associated with HFNC failure in multivariate analysis. In daily care, over one fourth of subjects requiring noninvasive ventilatory support were treated via HFNC, with a high success rate in subjects with severe ARDS. We conclude that HFNC may be considered as first-line therapy in ARF, including patients with ARDS.

Messika J ，Ben Ahmed K ，Gaudry S ，Miguel-Montanes R ，Rafat C ，Sztrymf B ，Dreyfuss D ，Ricard JD ... -  《-》

High-Flow Nasal Cannula Versus Bag-Valve-Mask for Preoxygenation Before Intubation in Subjects With Hypoxemic Respiratory Failure.

Critically ill patients with respiratory failure undergoing intubation have an increased risk of hypoxemia-related complications. Delivering oxygen via a high-flow nasal cannula (HFNC) has theoretical advantages and is increasingly used. This study was conducted to compare HFNC with bag-valve-mask (BVM) for preoxygenation and to assess oxygenation during intubation in subjects with hypoxemic respiratory failure. This study was a randomized controlled trial including 40 critically ill subjects with hypoxemic respiratory failure who received either HFNC or BVM for preoxygenation before intubation in the ICU. The primary outcome was the mean lowest SpO2 during intubation. The mean lowest SpO2 during intubation was 89 ± 18% in the HFNC group and 86 ± 11% in the BVM group (P = .56). In subjects receiving HFNC, a significant increase in SpO2 after preoxygenation was only seen in those previously receiving low-flow oxygen (P = .007), whereas there was no significant difference in SpO2 in subjects previously receiving noninvasive ventilation or HFNC (P = .73). During the 1 min of apnea after the induction of anesthesia, SpO2 dropped significantly in the BVM group (P = .001), whereas there was no significant decrease in the HFNC group (P = .17). There were no significant differences between the 2 groups at any of the predefined time points before or after intubation concerning SpO2 , PaO2 /FIO2 , and PaCO2 . Preoxygenation using HFNC before intubation was feasible and safe compared with BVM in critically ill subjects with acute, mild to moderate hypoxemic respiratory failure. There was no significant difference in the mean lowest SpO2 during intubation between the HFNC and the BVM group. There was also no significant difference in SpO2 between the 2 groups at any of the predefined time points. However, on continuous monitoring, there was a significant decrease in SpO2 during the apnea phase before intubation in the BVM group, which was not seen in the HFNC group. (ClinicalTrials.gov registration NCT01994928.).

Simon M ，Wachs C ，Braune S ，de Heer G ，Frings D ，Kluge S ... -  《-》

High flow nasal cannula versus conventional oxygen therapy and non-invasive ventilation in adults with acute hypoxemic respiratory failure: A systematic review.

Humidified oxygen via a high flow nasal cannula (HFNC) is a form of supplemental oxygen therapy that has significant theoretical advantages over conventional oxygen therapy (COT). However, the clinical role of HFNC in acute hypoxemic respiratory failure (AHRF) has not been well established. This review compares the efficacy of HFNC with COT and non-invasive ventilation (NIV) in patients with AHRF. Studies reviewed were selected based on relevance from a systematic literature search conducted in Medline and EMBASE to include all published original research through May 2016. Twelve studies matched the inclusion criteria. In the majority of the studies, HFNC was associated with superior comfort and patient tolerance as compared to NIV or COT. HFNC was associated with reduced work of breathing in comparison with COT in some, but not all, studies in the review. COT and NIV were associated with a higher 90-day mortality rate compared to HFNC in only one multicenter randomized trial versus no mortality difference reported by others. Three out of four studies demonstrated a decreased need for escalation of oxygen therapy with HFNC. Six out of eight studies demonstrated improved oxygenation with HFNC as compared to COT. Two of three studies revealed worse oxygenation with HFNC as compared to NIV. This review suggests that HFNC may be superior to COT in AHRF patients in terms of oxygenation, patient comfort, and work of breathing. It may be reasonable to consider HFNC as an intermediate level of oxygen therapy between COT and NIV.

Lee CC ，Mankodi D ，Shaharyar S ，Ravindranathan S ，Danckers M ，Herscovici P ，Moor M ，Ferrer G ... -  《-》

High-flow nasal cannula therapy in do-not-intubate patients with hypoxemic respiratory distress.

Peters SG ，Holets SR ，Gay PC 《-》