High-Flow Nasal Cannula Therapy for Respiratory Support in Adult Intensive Care Unit Patients

Abstract

What is the effectiveness of high-flow nasal cannula (HFNC) therapy compared with standard oxygen therapy, noninvasive ventilation, or noninvasive positive pressure (NIPPV) ventilation for respiratory support in adults in the intensive care unit?Critically ill patients are at high risk for severe hypoxemia that can lead to significant tissue damage and death if not corrected. Supplemental oxygen can be delivered via multiple methods, including mechanical ventilation, noninvasive ventilation, NIPPV, HFNC therapy, and low-flow nasal cannula (LFNC) therapy.1 Up to 40% of all patients admitted to the intensive care unit (ICU) receive mechanical ventilation; although this method is often necessary, it presents risks and potential complications, including trauma to the pulmonary system and increased mortality.2,3To avoid these complications, the use of alternative methods of respiratory support that can provide adequate oxygen levels is often considered. Use of LFNC therapy can be helpful but often cannot provide a sufficiently high level of oxygen for critically ill patients. However, HFNC therapy can provide high levels of oxygen, and its use in the ICU has been growing in recent years.4High-flow nasal cannula therapy delivers heated and humidified oxygen via the nose at high flow rates of up to 60 L/min. The high flow rates produce low levels of positive pressure in the upper airways, which can clear out expired carbon dioxide, leading to reduced work of breathing and decreased respiratory rate.5 Noninvasive positive pressure ventilation, which refers primarily to continuous positive airway pressure or bilevel positive airway pressure ventilation, can be used when patients require high levels of supplemental oxygen and need some level of mechanical support. The oxygen is delivered via a tight-fitting mask, typically over the nose, mouth, or both; this mask can be uncomfortable and make it difficult to maintain adequate positioning.6The purpose of this review was to compare the efficacy and safety of HFNC therapy with those of the other common noninvasive respiratory support methods in the ICU setting.This summary was based on an update to a previously published systematic review conducted in 2017.7 As new evidence on a topic becomes available, updates are necessary to account for the results that the new evidence presents. This update, conducted by Lewis et al,8 included 31 randomized controlled trials comprising 5136 adult participants. The authors of this review investigated several outcomes, with the primary ones being treatment failure (need to escalate to invasive ventilation), in-hospital mortality, and adverse events (pneumonia).The authors independently assessed the risk of bias for each study, including selection, performance, detection, attrition, reporting, and publication biases. They resolved any disagreements by reviewing the data together and through discussion.Lewis et al8 used risk ratios (RRs) with 95% CIs for dichotomous outcomes as measures of treatment effect between various comparisons and outcomes. They used the internationally approved Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach to determine the certainty of evidence—high, moderate, low, or very low—for each outcome9: This review showed that, overall, there was little or no difference in the evidence when comparing HFNC use with standard oxygen therapy or NIPPV in the outcomes explored. There was low-certainty evidence showing that HFNC therapy may lead to less treatment failure compared with standard oxygen therapy, with the classification of low certainty based on heterogeneity (differences in how the studies were conducted) and an unclear risk of bias in the studies.Currently, more than 50 studies are being conducted on the use of HFNC therapy; this high level of research activity is likely related to the increase in the use of HFNC therapy resulting from the COVID-19 pandemic. Upon publication, these studies can be added to the evaluation to provide additional guidance.The evidence from this systematic review can affect the decisions of clinical care teams when they are creating treatment plans for critically ill patients. Advocating for the best evidence-based treatment remains an important part of the role of critical care nurses. We must always consider the best available evidence and understand the feasibility, appropriateness, meaningfulness, and effectiveness of any intervention to determine whether it is suitable to implement in our individual context.