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Concept: Nasal cannula


Background Whether noninvasive ventilation should be administered in patients with acute hypoxemic respiratory failure is debated. Therapy with high-flow oxygen through a nasal cannula may offer an alternative in patients with hypoxemia. Methods We performed a multicenter, open-label trial in which we randomly assigned patients without hypercapnia who had acute hypoxemic respiratory failure and a ratio of the partial pressure of arterial oxygen to the fraction of inspired oxygen of 300 mm Hg or less to high-flow oxygen therapy, standard oxygen therapy delivered through a face mask, or noninvasive positive-pressure ventilation. The primary outcome was the proportion of patients intubated at day 28; secondary outcomes included all-cause mortality in the intensive care unit and at 90 days and the number of ventilator-free days at day 28. Results A total of 310 patients were included in the analyses. The intubation rate (primary outcome) was 38% (40 of 106 patients) in the high-flow-oxygen group, 47% (44 of 94) in the standard group, and 50% (55 of 110) in the noninvasive-ventilation group (P=0.18 for all comparisons). The number of ventilator-free days at day 28 was significantly higher in the high-flow-oxygen group (24±8 days, vs. 22±10 in the standard-oxygen group and 19±12 in the noninvasive-ventilation group; P=0.02 for all comparisons). The hazard ratio for death at 90 days was 2.01 (95% confidence interval [CI], 1.01 to 3.99) with standard oxygen versus high-flow oxygen (P=0.046) and 2.50 (95% CI, 1.31 to 4.78) with noninvasive ventilation versus high-flow oxygen (P=0.006). Conclusions In patients with nonhypercapnic acute hypoxemic respiratory failure, treatment with high-flow oxygen, standard oxygen, or noninvasive ventilation did not result in significantly different intubation rates. There was a significant difference in favor of high-flow oxygen in 90-day mortality. (Funded by the Programme Hospitalier de Recherche Clinique Interrégional 2010 of the French Ministry of Health; FLORALI number, NCT01320384 .).

Concepts: Oxygen, Intensive care medicine, Hypoxia, Partial pressure, Oxygen therapy, Breathing gas, Nasal cannula, Hypoxemia


Background High-flow oxygen therapy through a nasal cannula has been increasingly used in infants with bronchiolitis, despite limited high-quality evidence of its efficacy. The efficacy of high-flow oxygen therapy through a nasal cannula in settings other than intensive care units (ICUs) is unclear. Methods In this multicenter, randomized, controlled trial, we assigned infants younger than 12 months of age who had bronchiolitis and a need for supplemental oxygen therapy to receive either high-flow oxygen therapy (high-flow group) or standard oxygen therapy (standard-therapy group). Infants in the standard-therapy group could receive rescue high-flow oxygen therapy if their condition met criteria for treatment failure. The primary outcome was escalation of care due to treatment failure (defined as meeting ≥3 of 4 clinical criteria: persistent tachycardia, tachypnea, hypoxemia, and medical review triggered by a hospital early-warning tool). Secondary outcomes included duration of hospital stay, duration of oxygen therapy, and rates of transfer to a tertiary hospital, ICU admission, intubation, and adverse events. Results The analyses included 1472 patients. The percentage of infants receiving escalation of care was 12% (87 of 739 infants) in the high-flow group, as compared with 23% (167 of 733) in the standard-therapy group (risk difference, -11 percentage points; 95% confidence interval, -15 to -7; P<0.001). No significant differences were observed in the duration of hospital stay or the duration of oxygen therapy. In each group, one case of pneumothorax (<1% of infants) occurred. Among the 167 infants in the standard-therapy group who had treatment failure, 102 (61%) had a response to high-flow rescue therapy. Conclusions Among infants with bronchiolitis who were treated outside an ICU, those who received high-flow oxygen therapy had significantly lower rates of escalation of care due to treatment failure than those in the group that received standard oxygen therapy. (Funded by the National Health and Medical Research Council and others; Australian and New Zealand Clinical Trials Registry number, ACTRN12613000388718 .).

Concepts: Oxygen, Clinical trial, Randomized controlled trial, Clinical research, Adverse event, Emergency medical services, Oxygen therapy, Nasal cannula


Respiratory failure is a leading cause of neonatal mortality in the developing world. Bubble continuous positive airway pressure (bCPAP) is a safe, effective intervention for infants with respiratory distress and is widely used in developed countries. Because of its high cost, bCPAP is not widely utilized in low-resource settings. We evaluated the performance of a new bCPAP system to treat severe respiratory distress in a low resource setting, comparing it to nasal oxygen therapy, the current standard of care.

Concepts: Pulmonology, Intensive care medicine, Developed country, Infant mortality, Respiratory system, Developing country, Cyprus, Nasal cannula


High-flow nasal cannula oxygen (HFNC) is a relatively new therapy used in adults with respiratory failure. Whether it is superior to conventional oxygen therapy (COT) or to noninvasive mechanical ventilation (NIV) remains unclear. The aim of the present study was to investigate whether HFNC was superior to either COT or NIV in adult acute respiratory failure patients.

Concepts: Time, Oxygen, Pulmonology, Mechanical ventilation, Emergency medical services, Respiration, Oxygen therapy, Nasal cannula


The nasal cannula has been a commonly used patient interface to provide supplemental oxygen since its introduction in the 1940s. Traditionally, it has been categorized as a low-flow device and capable of delivering a 0.4 F(IO(2)) with flows up to 6 L/min to adults with normal minute ventilation. However, there is considerable performance variability among patients and design, which results in an exponential decline in delivered F(IO(2)) as breathing frequencies increase. The nasal cannula has also been successfully adapted for use in perinatal and pediatric respiratory care; flows are reduced, in the range of 0.25-1 L/min, due to smaller minute volumes. A decade or so ago, high-flow nasal cannula (HFNC) oxygen therapy was introduced, accompanied by heated humidification systems to prevent the associated drying of upper airway mucosa and to increase patient comfort. Therapeutic flows for adults were in the 15-40 L/min range; F(IO(2)) could be independently adjusted with air/O(2) blending. The HFNC has also found additional clinical application in perinatal care, as delivery systems with flows > 2 L/min could create a distending pressure similar to nasal CPAP. There is a small but growing body of information from clinical trials that supports use of HFNC as an alternative oxygen interface for adults who present with moderate hypoxemia that persists after receiving oxygen by reservoir-bag masks or similar therapy. Clinical observations report greater patient acceptance and comfort versus oxygen masks. HFNC therapy has also been considered valuable in perinatal care in treating the respiratory distress syndrome or supporting patients after extubation similar to nasal CPAP. At present, research-based evidence for the role of HFNC for its perinatal applications remains unclear. This review will identify proposed mechanisms for therapeutic effectiveness, current delivery equipment, guidelines for rational patient application, and direction for further research.

Concepts: Oxygen, Medicine, Acute respiratory distress syndrome, Oxygen therapy, Oxygen mask, Nasal cannula, Oxygen tent


BACKGROUND: High flow nasal cannula (HFNC) systems utilize higher gas flow rates than standard nasal cannulae. The use of HFNC as a respiratory support modality is increasing in the infant, pediatric, and adult populations as an alternative to non-invasive positive pressure ventilation. OBJECTIVES: This critical review aims to: (1) appraise available evidence with regard to the utility of HFNC in neonatal, pediatric, and adult patients; (2) review the physiology of HFNC; (3) describe available HFNC systems (online supplement); and (4) review ongoing and planned trials studying the utility of HFNC in various clinical settings. RESULTS: Clinical neonatal studies are limited to premature infants. Only a few pediatric studies have examined the use of HFNC, with most focusing on this modality for viral bronchiolitis. In critically ill adults, most studies have focused on acute respiratory parameters and short-term physiologic outcomes with limited investigations focusing on clinical outcomes such as duration of therapy and need for escalation of ventilatory support. Current evidence demonstrates that HFNC generates positive airway pressure in most circumstances; however, the predominant mechanism of action in relieving respiratory distress is not well established. CONCLUSION: Current evidence suggests that HFNC is well tolerated and may be feasible in a subset of patients who require ventilatory support with non-invasive ventilation. However, HFNC has not been demonstrated to be equivalent or superior to non-invasive positive pressure ventilation, and further studies are needed to identify clinical indications for HFNC in patients with moderate to severe respiratory distress.

Concepts: Medicine, Infant, Critical thinking, Pulmonology, Intensive care medicine, Acute respiratory distress syndrome, Pediatrics, Nasal cannula


To compare the short term benefit of high-flow nasal oxygen cannula (HFNC) with non-rebreathing mask in terms of change of dyspnea, physiologic variables, and patient comfort in subjects after endotracheal extubation.

Concepts: Oxygen, Chronic obstructive pulmonary disease, Term, Finance, Nasal cannula


High-flow nasal cannula use in the PICU continues to increase; however, a protocol for weaning patients has yet to be published. This study aimed to create an efficient and safe protocol for weaning high-flow nasal cannula.

Concepts: Nasal cannula


High flow nasal cannula (HFNC) oxygen therapy is a non-invasive form of respiratory support that is rapidly being taken up in paediatric intensive care units (PICU). For infants with bronchiolitis - who are the largest non-elective source of admissions to a PICU - there is some evidence that using HFNC therapy reduces the need for intubation and mechanical ventilation. The aim of this review article is is to explore, describe, critique and add to the evidence surrounding the use of HFNC therapy in the pediatric population for the management of respiratory distress.

Concepts: Oxygen, Medicine, Infant, Intensive care medicine, Physician, Pediatrics, Oxygen therapy, Nasal cannula


This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2018. Other selected articles can be found online at . Further information about the Annual Update in Intensive Care and Emergency Medicine is available from .

Concepts: Medicine, Review, Book review, Nasal cannula