Noninvasive vs conventional mechanical ventilation in acute respiratory failure: a multicenter, randomized controlled trial

When to intubate in acute hypoxaemic respiratory failure? Options and opportunities for evidence-informed decision making in the intensive care unit

The optimal timing of intubation in acute hypoxaemic respiratory failure is uncertain and became a point of controversy during the COVID-19 pandemic. Invasive mechanical ventilation is a potentially life-saving intervention but carries substantial risks, including injury to the lungs and diaphragm, pneumonia, intensive care unit-acquired muscle weakness, and haemodynamic impairment. In deciding when to intubate, clinicians must balance premature exposure to the risks of ventilation with the potential harms of unassisted breathing, including disease progression and worsening multiorgan failure. Currently, the optimal timing of intubation is unclear. In this Personal View, we examine a range of parameters that could serve as triggers to initiate invasive mechanical ventilation. The utility of a parameter (eg, the ratio of arterial oxygen tension to fraction of inspired oxygen) to predict the likelihood of a patient undergoing intubation does not necessarily mean that basing the timing of intubation on that parameter will improve therapeutic outcomes. We examine options for clinical investigation to make progress on establishing the optimal timing of intubation.

Noninvasive respiratory support in the emergency department: Controversies and state-of-the-art recommendations

Acute respiratory failure is a common reason for emergency department visits and hospital admissions. Diverse underlying physiologic abnormalities lead to unique aspects about the most common causes of acute respiratory failure: acute decompensated heart failure, acute exacerbation of chronic obstructive pulmonary disease, and acute de novo hypoxemic respiratory failure. Noninvasive respiratory support strategies are increasingly used methods to support work of breathing and improve gas exchange abnormalities to improve outcomes relative to conventional oxygen therapy or invasive mechanical ventilation. Noninvasive respiratory support includes noninvasive positive pressure ventilation and nasal high flow, each with unique physiologic mechanisms. This paper will review the physiology of respiratory failure and noninvasive respiratory support modalities and offer data and guideline-driven recommendations in the context of key clinical controversies.

Oxygenation thresholds for invasive ventilation in hypoxemic respiratory failure: a target trial emulation in two cohorts

BACKGROUND

The optimal thresholds for the initiation of invasive ventilation in patients with hypoxemic respiratory failure are unknown. Using the saturation-to-inspired oxygen ratio (SF), we compared lower versus higher hypoxemia severity thresholds for initiating invasive ventilation.

METHODS

This target trial emulation included patients from the Medical Information Mart for Intensive Care (MIMIC-IV, 2008-2019) and the Amsterdam University Medical Centers (AmsterdamUMCdb, 2003-2016) databases admitted to intensive care and receiving inspired oxygen fraction ≥ 0.4 via non-rebreather mask, noninvasive ventilation, or high-flow nasal cannula. We compared the effect of using invasive ventilation initiation thresholds of SF < 110, < 98, and < 88 on 28-day mortality. MIMIC-IV was used for the primary analysis and AmsterdamUMCdb for the secondary analysis. We obtained posterior means and 95% credible intervals (CrI) with nonparametric Bayesian G-computation.

RESULTS

We studied 3,357 patients in the primary analysis. For invasive ventilation initiation thresholds SF < 110, SF < 98, and SF < 88, the predicted 28-day probabilities of invasive ventilation were 72%, 47%, and 19%. Predicted 28-day mortality was lowest with threshold SF < 110 (22.2%, CrI 19.2 to 25.0), compared to SF < 98 (absolute risk increase 1.6%, CrI 0.6 to 2.6) or SF < 88 (absolute risk increase 3.5%, CrI 1.4 to 5.4). In the secondary analysis (1,279 patients), the predicted 28-day probability of invasive ventilation was 50% for initiation threshold SF < 110, 28% for SF < 98, and 19% for SF < 88. In contrast with the primary analysis, predicted mortality was highest with threshold SF < 110 (14.6%, CrI 7.7 to 22.3), compared to SF < 98 (absolute risk decrease 0.5%, CrI 0.0 to 0.9) or SF < 88 (absolute risk decrease 1.9%, CrI 0.9 to 2.8).

CONCLUSION

Initiating invasive ventilation at lower hypoxemia severity will increase the rate of invasive ventilation, but this can either increase or decrease the expected mortality, with the direction of effect likely depending on baseline mortality risk and clinical context.

Non-invasive ventilation for preoxygenation before general anesthesia: a systematic review and meta-analysis of randomized controlled trials

Background and objectives

Preoxygenation is crucial for providing sufficient oxygen reservoir to a patient before intubation and enables the extension of the period between breathing termination and critical desaturation (safe apnoea time). Conventionally, face mask ventilation is used for preoxygenation. Non-invasive ventilation is a new preoxygenation method. The study objective was to compare the outcomes of non-invasive ventilation and face mask ventilation for preoxygenation.

Method

PubMed, Embase, Cochrane Library, and the ClinicalTrials.gov registry were searched for eligible studies published from database inception to September 2021. Individual effect sizes were standardized, and a meta-analysis was conducted using random effects models to calculate the pooled effect size. Inclusion criteria were randomised controlled trials of comparing the outcomes of non-invasive ventilation or face mask ventilation for preoxygenation in patients scheduled for surgeries. The primary outcome was safe apnea time, and the secondary outcomes were post-operative complications, number of patients who achieved the expired O₂ fraction (FeO₂) after 3 min of preoxygenation, minimal SpO₂ during tracheal intubation, partial pressure of oxygen in the arterial blood (PaO₂) and partial pressure of carbon dioxide (PaCO₂) after preoxygenation, and PaO₂ and PaCO₂ after tracheal intubation.

Results

13 trials were eligible for inclusion in this study. Significant differences were observed in safe apnoea time, number of patients who achieved FeO₂ 90% after preoxygenation for 3 min, and PaO₂ and PaCO₂ after preoxygenation and tracheal intubation. Only in the non-obese subgroup, no significant difference was observed in safe apnoea time (mean difference: 125.38, 95% confidence interval: − 12.26 to 263.03).

Conclusion

Non-invasive ventilation appeared to be more effective than conventional methods for preoxygenation. We recommend non-invasive ventilation based on our results.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-022-01842-y.

Comparison of Local and Systemic Inflammation During Invasive Versus Noninvasive Ventilation in Rats

The impact of noninvasive ventilation (NIV) on local and systemic inflammation is poorly characterized, particularly when compared with invasive mechanical ventilation (IMV). We sought to quantify the local and systemic inflammatory response of these 2 respiratory treatments in rats with lipopolysaccharide (LPS)-induced lung injury (LPS-injured) and healthy rats. Animals were subjected to 4 h of NIV or IMV treatments at noninjurious settings, or 4 h of control treatment in which healthy or LPS-injured animals remained spontaneously breathing under isoflurane anesthesia with no respiratory support. Cytokines were then quantified in the serum and lung tissue by multiplex enzyme-linked immunosorbent assay. Contrary to our hypothesis, there were no significant differences in cytokine levels in serum or lung when comparing the NIV- and IMV-treated groups; this was true in both LPS-injured and healthy rats. However, within the LPS-injured group, pulmonary levels of interleukin (IL)-1α, IL-6, and tumor necrosis factor α were significantly lower in the NIV-treated group than in control but not in the IMV-treated group compared with control. We conclude that NIV, unlike IMV, could attenuate local inflammation.

Validation of an Electronic Phenotyping Algorithm for Patients With Acute Respiratory Failure

Acute respiratory failure is a common reason for ICU admission and imposes significant strain on patients and the healthcare system. Noninvasive positive-pressure ventilation and high-flow nasal oxygen are increasingly used as an alternative to invasive mechanical ventilation to treat acute respiratory failure. As such, there is a need to accurately cohort patients using large, routinely collected, clinical data to better understand utilization patterns and patient outcomes. The primary objective of this retrospective observational study was to externally validate our computable phenotyping algorithm for patients with acute respiratory failure requiring various sequences of respiratory support in real-world data from a large healthcare delivery network.

Nebulized heparin and salbutamol versus salbutamol alone in acute exacerbations of chronic obstructive pulmonary disease requiring mechanical ventilation: a double-blind randomized controlled trial

Background

Nebulized heparin has been effectively used in the management of many pulmonary diseases. However, its effect on mechanically ventilated patients with acute exacerbation chronic obstructive pulmonary disease (AECOPD) has never been studied. This study aimed to assess the efficacy of nebulized heparin and salbutamol to increase ventilator-free days (VFD) in mechanically ventilated AECOPD patients and the effect of nebulized heparin on respiratory and coagulation functions.

Methods

In this double-blind controlled study, 60 mechanically ventilated adult patients with AECOPD were randomly allocated into two groups; heparin and salbutamol (HS) group and salbutamol only (S) group. In the HS group, patients received nebulized heparin (25,000 IU) and salbutamol (5 mg) every 6 hours. Patients in the S group received nebulized salbutamol only (5 mg). The treatment was continued while patients remained ventilated for a maximum of 14 days. The primary outcome was VFDs at day 14. PaCO2, PaO2/FiO2 ratio, number of nebulizations withheld, C-reactive protein (CRP) titer and activated partial thromboplastin time (APTT) were secondary outcomes.

Results

Patients in the Group HS had significantly more VFDs 4.7 ± 3.3 compared with those in the Group S 2.4 ± 2.6, P = 0.007. PaCO2 levels, PaO2/FiO2, the decrease in the CRP level and the increase in the APTT from the baseline showed no evidence of difference in both groups.

Conclusions

The co-administration of nebulized heparin and salbutamol, compared with salbutamol alone, significantly increased (VFDs) among mechanically ventilated AECOPD patients without increasing bleeding risks.

Acute respiratory failure in randomized trials of noninvasive respiratory support: A systematic review of definitions, patient characteristics, and criteria for intubation

PURPOSE

To examine the definitions of acute respiratory failure, the characteristics of recruited patients, and the criteria for intubation used in randomized trials.

METHODS

We searched MEDLINE for randomized trials of noninvasive respiratory support modalities in patients with de novo respiratory failure. We included trials from 1995 to 2017 that enrolled 40 or more patients and used intubation as an outcome.

RESULTS

We examined the reports of 53 trials that enrolled 7225 patients. There was wide variation in the use of variables for defining acute respiratory failure. Dyspnea was rarely measured and the increase in breathing effort was poorly defined. The characteristics of patients enrolled in trials changed over time and differed by the cause of respiratory failure. Intubation was poorly characterized. The criteria for intubation had more variables than the criteria for respiratory failure.

CONCLUSIONS

We identified deficiencies in the design and reporting of randomized trials, some of which can be remedied by investigators. We also found that patient characteristics differ by the type of respiratory failure. This knowledge can help clinician identify patients at the right moment to benefit from the tested interventions and investigators in developing criteria for enrollment in future trials.

Noninvasive ventilation as acute therapy

PURPOSE OF REVIEW

Noninvasive ventilation (NIV) is widely used in ICU patients to treat or to prevent acute respiratory failure. Whereas its physiological effects are clearly beneficial in hypercapnic patients, it could be deleterious in hypoxemic patients without hypercapnia.

RECENT FINDINGS

NIV should be cautiously used in patients with de-novo respiratory failure, the vast majority of whom meet the criteria for acute respiratory distress syndrome. Spontaneous breathing with high tidal volumes may worsen lung injury in these patients, and recent findings suggest that NIV may increase the risk of mortality. Even though high-flow oxygen therapy is increasingly applied in this context, NIV remains recommended for management of immunocompromised patients with acute respiratory failure. NIV should be the first-line oxygenation strategy in patients with acute hypercapnic respiratory failure when pH is equal to or below 7.35. Prophylactic NIV prevents respiratory failure after extubation of patients at high risk of reintubation.

SUMMARY

Most previous studies have compared NIV with standard oxygen, and recent recommendations have been established from these findings. Given the growing use of high-flow oxygen therapy, new studies are needed to compare NIV versus high-flow oxygen therapy so as to better define the appropriate indications for each treatment.

Is immunosuppression status a risk factor for noninvasive ventilation failure in patients with acute hypoxemic respiratory failure? A post hoc matched analysis

Background

Recent European/American guidelines recommend noninvasive ventilation (NIV) as a first-line therapy to manage acute hypoxemic respiratory failure in immunocompromised patients. By contrast, NIV may have deleterious effects in nonimmunocompromised patients and experts have been unable to offer a recommendation. Immunocompromised patients have particularly high mortality rates when they require intubation. However, it is not clear whether immunosuppression status is a risk factor for NIV failure. We assessed the impact of immunosuppression status on NIV failure in a post hoc analysis pooling two studies including patients with de novo acute hypoxemic respiratory failure treated with NIV. Patients with hypercapnia, acute exacerbation of chronic lung disease, cardiogenic pulmonary edema, or with do-not-intubate order were excluded.

Results

Among the 208 patients included in the analysis, 71 (34%) were immunocompromised. They had higher severity scores upon ICU admission, higher pressure-support levels, and minute ventilation under NIV, and were more likely to have bilateral lung infiltrates than nonimmunocompromised patients. Intubation and in-ICU mortality rates were higher in immunocompromised than in nonimmunocompromised patients: 61% vs. 43% (p = 0.02) and 38% vs. 15% (p < 0.001), respectively. After adjustment or using a propensity score-matched analysis, immunosuppression was not associated with intubation, whereas it remained independently associated with ICU mortality with an adjusted odds ratio of 2.64 (95% CI 1.24–5.67, p = 0.01).

Conclusions

Immunosuppression status may directly influence mortality but does not seem to be associated with an increased risk of intubation in patients with de novo acute hypoxemic respiratory failure treated with NIV. Studies in this specific population are needed.

Electronic supplementary material

The online version of this article (10.1186/s13613-019-0566-z) contains supplementary material, which is available to authorized users.

Noninvasive ventilation versus oxygen therapy in patients with acute respiratory failure

PURPOSE OF REVIEW

High-flow nasal cannula oxygen therapy (HFOT) is becoming an alternative to noninvasive ventilation (NIV) and standard oxygen in management of patients with acute respiratory failure.

RECENT FINDINGS

Patients with de novo acute respiratory failure should be managed with HFOT rather than NIV. Indeed, the vast majority of patients with de novo respiratory failure meet the criteria for ARDS, and NIV does not seem protective, as patients generate overly high tidal volume that may worsen underlying lung injury. However, NIV remains the first-line oxygenation strategy in postoperative patients and those with acute hypercapnic respiratory failure when pH is equal to or below 7.35. During preoxygenation, NIV also seems to be more efficient than standard oxygen using valve-bag mask to prevent profound oxygen desaturation. In postoperative cardiothoracic patients, HFOT could be an alternative to NIV in the management of acute respiratory failure.

SUMMARY

Recent recommendations for managing patients with acute respiratory failure have been established on the basis of studies comparing NIV with standard oxygen. Growing use of HFOT will lead to new studies comparing NIV versus HFOT in view of more precisely defining the appropriate indications for each treatment.

High flow nasal cannula oxygen versus noninvasive ventilation in adult acute respiratory failure: a systematic review of randomized-controlled trials

We reviewed the use of noninvasive ventilation (NIV) versus high flow nasal cannula (HFNC) oxygen in adult acute respiratory failure (ARF). We searched major databases and included randomized trials comparing at least NIV with HFNC or NIV+HFNC with NIV in ARF. Primary outcomes included intubation/re-intubation rates. Secondary outcomes were ICU mortality and morbidities. Five trials were included; three compared HFNC with NIV, one compared HFNC, NIV and oxygen whereas one compared HFNC+NIV with NIV. Patients had hypoxaemic ARF (PaO2/FiO2≤300 mmHg). Heterogeneity prevented result pooling. Three and two studies had superiority and noninferiority design, respectively. Patients were postcardiothoracic surgery, mixed medical/surgical patients and those with pneumonia. Two trials were conducted after extubation, two before intubation and one during intubation. Three trials reported intubation/re-intubation rates as the primary outcomes. The other two trials reported the lowest peripheral capillary oxygen saturation readings during bronchoscopy or intubation. In the former three trials, the odds ratio for intubation/re-intubation rates between HFNC versus the NIV group ranged from 0.80 (95% confidence interval: 0.54-1.19) to 1.65 (95% confidence interval: 0.96-2.84). In the latter two trials, only one reported a difference in the lowest peripheral capillary oxygen saturation between NIV+HFNC versus the NIV group during intubation [100% (interquartile range: 95-100) vs. 96% (interquartile range: 92-99); P=0.029]. The secondary outcomes included differences in ICU mortality and patient tolerability, favouring HFNC. Results were conflicting, but highlighted future research directions. These include patients with hypercapneic ARF, more severe hypoxaemia (PaO2/FiO2≤200 mmHg), a superiority design, an oxygen arm and patient-centred outcomes.

Non-invasive ventilation or high-flow oxygen therapy: When to choose one over the other?

It has been found that high-flow oxygen therapy (HFOT) can reduce mortality of patients admitted to intensive care unit (ICU) for de novo acute respiratory failure (ARF) as compared to non-invasive ventilation (NIV). HFOT might therefore be considered as a first-line strategy of oxygenation in these patients. The beneficial effects of HFOT may be explained by its good tolerance and by physiological characteristics including delivery of high FiO₂ , positive end expiratory pressure (PEEP) effect and continuous dead space washout contributing to decreased work of breathing. In contrast, NIV should be used cautiously in patients with de novo ARF due to high tidal volumes promoted by pressure support and that may potentially worsen pre-existing lung injury. Although recent studies have reported no benefit and even deleterious effects of NIV in immunocompromised patients with ARF, the experts have recommended its use as a first-line strategy. In patients with acute-on-chronic respiratory failure and respiratory acidosis, it has been clearly shown that NIV is the best strategy of oxygenation. However, HFOT seems able to reverse respiratory acidosis and further studies are needed to evaluate whether HFOT could represent an alternative to standard oxygen. Although NIV is recommended to treat ARF in post-operative patients or to prevent post-extubation respiratory failure in ICU, recent large-scale randomized studies suggest that HFOT could be equivalent to NIV. While recent recommendations have been established from studies comparing NIV with standard oxygen, new studies are needed to compare NIV versus HFOT in order to better define the appropriate indications for both treatments.

The efficacy of initial ventilation strategy for adult immunocompromised patients with severe acute hypoxemic respiratory failure: study protocol for a multicentre randomized controlled trial (VENIM)

Background

Acute respiratory failure (ARF) is still one of the most severe complications in immunocompromised patients. Our previous systematic review showed noninvasive mechanical ventilation (NIV) reduced mortality, length of hospitalization and ICU stay in AIDS/hematological malignancy patients with relatively less severe ARF, compared to invasive mechanical ventilation (IMV). However, this systematic review was based on 13 observational studies and the quality of evidence was low to moderate. The efficacy of NIV in more severe ARF and in patients with other causes of immunodeficiency is still unclear. We aim to determine the efficacy of the initial ventilation strategy in managing ARF in immunocompromised patients stratified by different disease severity and causes of immunodeficiency, and explore predictors for failure of NIV.

Methods and analysis

The VENIM is a multicentre randomized controlled trial (RCT) comparing the effects of NIV compared with IMV in adult immunocompromised patients with severe hypoxemic ARF. Patients who meet the indications for both forms of ventilatory support will be included. Primary outcome will be 30-day all-cause mortality. Secondary outcomes will include in-hospital mortality, length of stay in hospital, improvement of oxygenation, nosocomial infections, seven-day organ failure, adverse events of intervention, et al. Subgroups with different disease severity and causes of immunodeficiency will also be analyzed.

Discussion

VENIM is the first randomized controlled trial aiming at assessing the efficacy of initial ventilation strategy in treating moderate and severe acute respiratory failure in immunocompromised patients. The result of this RCT may help doctors with their ventilation decisions.

Trial registration

ClinicalTrials.gov NCT02983851. Registered 2 September 2016.

Outcomes for Children Receiving Noninvasive Ventilation as the First-Line Mode of Mechanical Ventilation at Intensive Care Admission: A Propensity Score-Matched Cohort Study

Supplemental Digital Content is available in the text.

Objectives:

To compare outcomes of children receiving noninvasive ventilation with those receiving invasive ventilation as first-line mode of mechanical ventilation following unplanned intensive care admission.

Design:

Propensity score-matched cohort study analyzing data prospectively collected by the Pediatric Intensive Care Audit Network over 8 years (2007–2014).

Setting:

Thirty-one PICUs in the United Kingdom and Ireland; twenty-one of whom submitted Pediatric Critical Care Minimum Dataset data for the entire study period.

Patients:

Children consecutively admitted to study PICUs. Planned admissions following surgery, unplanned admissions from other hospitals, those on chronic ventilation, and those who did not receive mechanical ventilation on the day of PICU admission were excluded.

Interventions:

Use of noninvasive ventilation, rather than invasive ventilation, as the first-line mode of mechanical ventilation.

Measurements and Main Results:

PICU mortality, length of ventilation, length of PICU stay, and ventilator-free days at day 28. During the study period, there were 151,128 PICU admissions. A total of 15,144 admissions (10%) were eligible for analysis once predefined exclusion criteria were applied: 4,804 (31.7%) received “noninvasive ventilation first,” whereas 10,221 (67.5%) received “invasive ventilation first”; 119 (0.8%) admissions could not be classified. Admitting PICU site explained 6.5% of the variation in first-line mechanical ventilation group (95% CI, 2.0–19.0%). In propensity score-matched analyses, receiving noninvasive ventilation first was associated with a significant reduction in mortality by 3.1% (95% CI, 1.7–4.6%), length of ventilation by 1.6 days (95% CI, 1.0–2.3), and length of PICU stay by 2.1 days (95% CI, 1.3–3.0), as well as an increase in ventilator-free days at day 28 by 3.7 days (95% CI, 3.1–4.3).

Conclusions:

Use of noninvasive ventilation as first-line mode of mechanical ventilation in critically ill children admitted to PICU in an unplanned fashion may be associated with significant clinical benefits. Further high-quality evidence regarding optimal patient selection and timing of initiation of noninvasive ventilation could lead to less variability in clinical care between institutions and improved patient outcomes.

Outcomes and predictors of failure of non-invasive ventilation in patients with community acquired pneumonia in the ED

OBJECTIVE

We set out to describe the use and analyze the predictors of non-invasive ventilation failure in patients with community-acquired pneumonia who receive non-invasive ventilation as first line ventilatory therapy in the emergency department.

METHODS

A retrospective cohort study was conducted among consecutive patients with community acquired pneumonia requiring ventilator support presenting to two tertiary care university-affiliated emergency departments. Multivariable logistic regression analysis was used to determine predictors of non-invasive ventilation failure at initiation of non-invasive ventilation and at two hours of non-invasive ventilation use; RESULT: After excluding patients with a do not resuscitate order status, 163 (74.8%) patients with community acquired pneumonia were initially treated with non-invasive ventilation on initial presentation to the emergency department. Non-invasive ventilation failure occurred in 50% of patients and was found to be associated with the absence of chronic obstructive airway disease, APACHE II score, the need for hemodynamic support and the number of CXR quadrants involved. Two-hour physiological parameters associated with non-invasive ventilation failure included higher respiratory rate, lower serum pH and the ongoing need of hemodynamic support.

CONCLUSION

In conclusion, the use of non-invasive ventilation to support patients presenting to the emergency department with respiratory failure and community acquired pneumonia is common and is associated with a significant failure rate. Hemodynamic support is a strong predictor of failure. The selection of the appropriate patient and monitoring of physiological parameters while on NIV is crucial to ensure successful treatment.

The clinical practice guideline for the management of ARDS in Japan

BACKGROUND

The Japanese Society of Respiratory Care Medicine and the Japanese Society of Intensive Care Medicine provide here a clinical practice guideline for the management of adult patients with ARDS in the ICU.

METHOD

The guideline was developed applying the GRADE system for performing robust systematic reviews with plausible recommendations. The guideline consists of 13 clinical questions mainly regarding ventilator settings and drug therapies (the last question includes 11 medications that are not approved for clinical use in Japan).

RESULTS

The recommendations for adult patients with ARDS include: we suggest against early tracheostomy (GRADE 2C), we suggest using NPPV for early respiratory management (GRADE 2C), we recommend the use of low tidal volumes at 6-8 mL/kg (GRADE 1B), we suggest setting the plateau pressure at 30cmH20 or less (GRADE2B), we suggest using PEEP within the range of plateau pressures less than or equal to 30cmH2O, without compromising hemodynamics (Grade 2B), and using higher PEEP levels in patients with moderate to severe ARDS (Grade 2B), we suggest using protocolized methods for liberation from mechanical ventilation (Grade 2D), we suggest prone positioning especially in patients with moderate to severe respiratory dysfunction (GRADE 2C), we suggest against the use of high frequency oscillation (GRADE 2C), we suggest the use of neuromuscular blocking agents in patients requiring mechanical ventilation under certain circumstances (GRADE 2B), we suggest fluid restriction in the management of ARDS (GRADE 2A), we do not suggest the use of neutrophil elastase inhibitors (GRADE 2D), we suggest the administration of steroids, equivalent to methylprednisolone 1-2mg/kg/ day (GRADE 2A), and we do not recommend other medications for the treatment of adult patients with ARDS (GRADE1B; inhaled/intravenous β2 stimulants, prostaglandin E1, activated protein C, ketoconazole, and lisofylline, GRADE 1C; inhaled nitric oxide, GRADE 1D; surfactant, GRADE 2B; granulocyte macrophage colony-stimulating factor, N-acetylcysteine, GRADE 2C; Statin.).

CONCLUSIONS

This article was translated from the Japanese version originally published as the ARDS clinical practice guidelines 2016 by the committee of ARDS clinical practice guideline (Tokyo, 2016, 293p, available from http://www.jsicm.org/ARDSGL/ARDSGL2016.pdf). The original article, written for Japanese healthcare providers, provides points of view that are different from those in other countries.

Effects of non-invasive ventilation in patients with acute respiratory failure excluding post-extubation respiratory failure, cardiogenic pulmonary edema and exacerbation of COPD: a systematic review and meta-analysis

BACKGROUND

This meta-analysis compared the effects of non-invasive ventilation (NIV) with invasive mechanical ventilation (InMV) and standard oxygen (O₂) therapy on mortality and rate of tracheal intubation in patients presenting acute respiratory failure (ARF).

METHODS

We searched the MEDLINE, EMBASE and Cochrane Central Register of clinical trials databases between 1949 and May 2015 to identify randomized trials of NIV for ARF. We excluded the ARF caused by extubation, cardiogenic pulmonary edema, and COPD.

RESULTS

The meta-analysis included 21 studies and 1691 patients, of whom 846 were assigned to NIV and 845 to control (InMV or standard O₂ therapy). One hundred ninety-one patients (22.6%) in the NIV group and 261 patients (30.9%) in the control group died before discharge from hospital. The pooled odds ratio (OR) for short-term mortality (in-hospital mortality) was 0.56 (95% CI 0.40-0.78). When comparing NIV with standard O₂ therapy, the short-term mortality was 155 (27.4%) versus 204 (36.0%), respectively. For this comparison, the pooled OR of short-term mortality was 0.56 (95% CI 0.36-0.85). When comparing NIV with InMV, the short-term mortality was 36 (12.9%) versus 57 (20.5%) patients, respectively. For this comparison, the pooled OR of short-term mortality was 0.56 (95% CI 0.34-0.90). Tracheal intubation was performed in 106 patients (22.7%) in the NIV and in 183 patients (39.4%) in the standard O₂ group, representing a pooled OR of 0.37 (95% CI 0.25-0.55). There were publication biases and the quality of the evidence was graded as low.

CONCLUSION

Compared with standard O₂ therapy or InMV, NIV lowered both the short-term mortality and the rate of tracheal intubation in patients presenting with ARF.

Noninvasive ventilation versus oxygen therapy for the treatment of acute respiratory failure

INTRODUCTION

There is an ongoing discussion on whether oxygen therapy or noninvasive ventilation (NIV) should be used in patient with acute respiratory failure. While respiratory acidosis, especially in case of COPD exacerbation, is a clear indication for NIV, data available in patients with acute hypoxemic respiratory failure (AHRF) are ambiguous. In addition, recently the use of nasal high flow (NHF) has been increased. Despite that NHF has been studied as an alternative to NIV, the clinical advantages of NHF need to be confirmed.

AREAS COVERED

The purpose of this review is to enhance our understanding about the management of AHRF in specific settings, focusing on recent papers in which NIV and standard oxygen or NHF have been compared. Expert commentary: The choice of the most appropriate strategy for AHRF treatment should be made based upon patient's clinical status, underlying diseases, level of required respiratory support and patient's tolerance and comfort.

Noninvasive and invasive positive pressure ventilation for acute respiratory failure in critically ill patients: a comparative cohort study

BACKGROUND

Noninvasive positive pressure ventilation (NPPV) for acute respiratory failure in the intensive care unit (ICU) is associated with a marked reduction in intubation rate, complications, hospital length of stay and mortality. Multiple studies have indicated that patients failing NPPV have worse outcomes compared with patients with successful NPPV treatment; however limited data is available on risks associated with NPPV failure resulting in (delayed) intubation and outcomes compared with initial intubation. The purpose of this study is to assess rates and predictors of NPPV failure and to compare hospital outcomes of patients with NPPV failure with those patients primarily intubated without a prior NPPV trial.

METHODS

A retrospective observational study using data from patients with acute respiratory failure admitted to the ICU in the period 2013-2014. All patients treated with NPPV were evaluated. A sample of patients who were primarily intubated was randomly selected to serve as controls for the group of patients who failed NPPV.

RESULTS

NPPV failure was recorded in 30.8% of noninvasively ventilated patients and was associated with longer ICU stay [OR, 1.16, 95% confidence interval (95% CI): 1.04-1.30] and lower survival rates (OR, 0.10, 95% CI: 0.02-0.59) compared with NPPV success. Multivariate analysis showed presence of severe sepsis at study entry, higher Simplified Acute Physiology II Score (SAPS-II) score, lower ratio of arterial oxygen tension to fraction of inspired oxygen (PF-ratio) and lower plasma glucose were predictors for NPPV failure. After controlling for potential confounders, patients with NPPV failure did not show any difference in hospital outcomes compared with patients who were primarily intubated.

CONCLUSIONS

Patients with acute respiratory failure and NPPV failure have worse outcomes compared with NPPV success patients, however not worse than initially intubated patients. An initial trial of NPPV therefore may be suitable in selected cases of patients with acute respiratory failure, since NPPV could be potentially beneficial and does not seem to result in worse outcome in case of NPPV failure compared to primary intubation. A prospective trial is warranted to confirm findings.

Noninvasive Ventilation for the Emergency Physician

Noninvasive ventilation (NIV) improves oxygenation and ventilation, prevents endotracheal intubation, and decreases the mortality rate in select patients with acute respiratory failure. Although NIV is used commonly for acute exacerbations of chronic obstructive pulmonary disease and acute cardiogenic pulmonary edema, there are emerging indications for its use in the emergency department. Emergency physicians must be knowledgeable regarding the indications and contraindications for NIV in emergency department patients with acute respiratory failure as well as the means of initiating it and monitoring patients who are receiving it.

Noninvasive ventilation for acute respiratory failure

PURPOSE OF REVIEW

This article reviews the use of noninvasive ventilation (NIV) in patients with acute respiratory failure (ARF), with a critical review of the most recent literature in this setting.

RECENT FINDINGS

The efficacy of NIV is variable depending on the cause of the episode of ARF. In community-acquired pneumonia, NIV is often associated with poor response, with better response in patients with preexisting cardiac or respiratory disease. In patients with pandemic influenza H1N1 and severe ARF, NIV has been associated with high failure rates but relatively favorable mortality. In acute respiratory distress syndrome, NIV should be used very cautiously and restricted to patients with mild-moderate acute respiratory distress syndrome without shock or metabolic acidosis due to the high failure rate observed in several reports. Despite limited evidence, NIV may improve the outcomes of patients with chest trauma and severe ARF. In postoperative ARF, both continuous positive airway pressure and NIV are effective to improve clinical outcomes, particularly in those with abdominal, cardiac, and thoracic surgery.

SUMMARY

Although patients with severe hypoxemic ARF are, in general, less likely to be intubated when NIV is used, the efficacy is different among these heterogeneous populations. Therefore, NIV is not routinely recommended in all patients with severe hypoxemic ARF.

Success/Failure Prediction of Noninvasive Mechanical Ventilation in Intensive Care Units. Using Multiclassifiers and Feature Selection Methods

OBJECTIVES

This paper addresses the problem of decision-making in relation to the administration of noninvasive mechanical ventilation (NIMV) in intensive care units.

METHODS

Data mining methods were employed to find out the factors influencing the success/failure of NIMV and to predict its results in future patients. These artificial intelligence-based methods have not been applied in this field in spite of the good results obtained in other medical areas.

RESULTS

Feature selection methods provided the most influential variables in the success/failure of NIMV, such as NIMV hours, PaCO2 at the start, PaO2 / FiO2 ratio at the start, hematocrit at the start or PaO2 / FiO2 ratio after two hours. These methods were also used in the preprocessing step with the aim of improving the results of the classifiers. The algorithms provided the best results when the dataset used as input was the one containing the attributes selected with the CFS method.

CONCLUSIONS

Data mining methods can be successfully applied to determine the most influential factors in the success/failure of NIMV and also to predict NIMV results in future patients. The results provided by classifiers can be improved by preprocessing the data with feature selection techniques.

Effectiveness and predictors of failure of noninvasive mechanical ventilation in acute respiratory failure

OBJECTIVE

To assess the effectiveness and identify predictors of failure of noninvasive ventilation.

DESIGN

A retrospective, longitudinal descriptive study was made.

SETTING

Adult patients with acute respiratory failure.

PATIENTS

A total of 410 consecutive patients with noninvasive ventilation treated in an Intensive Care Unit of a tertiary university hospital from 2006 to 2011.

PROCEDURES

Noninvasive ventilation.

MAIN VARIABLES OF INTEREST

Demographic variables and clinical and laboratory test parameters at the start and two hours after the start of noninvasive ventilation. Evolution during admission to the Unit and until hospital discharge.

RESULTS

The failure rate was 50%, with an overall mortality rate of 33%. A total of 156 patients had hypoxemic respiratory failure, 87 postextubation respiratory failure, 78 exacerbation of chronic obstructive pulmonary disease, 61 hypercapnic respiratory failure without chronic obstructive pulmonary disease, and 28 had acute pulmonary edema. The failure rates were 74%, 54%, 27%, 31% and 21%, respectively. The etiology of respiratory failure, serum bilirubin at the start, APACHEII score, radiological findings, the need for sedation to tolerate noninvasive ventilation, changes in level of consciousness, PaO2/FIO2 ratio, respiratory rate and heart rate from the start and two hours after the start of noninvasive ventilation were independently associated to failure.

CONCLUSIONS

The effectiveness of noninvasive ventilation varies according to the etiology of respiratory failure. Its use in hypoxemic respiratory failure and postextubation respiratory failure should be assessed individually. Predictors of failure could be useful to prevent delayed intubation.

Outcomes associated with invasive and noninvasive ventilation among patients hospitalized with exacerbations of chronic obstructive pulmonary disease

IMPORTANCE

Small clinical trials have shown that noninvasive ventilation (NIV) is efficacious in reducing the need for intubation and improving short-term survival among patients with severe exacerbations of chronic obstructive pulmonary disease (COPD). Little is known, however, about the effectiveness of NIV in routine clinical practice.

OBJECTIVE

To compare the outcomes of patients with COPD treated with NIV to those treated with invasive mechanical ventilation (IMV).

DESIGN, SETTING, AND PARTICIPANTS

This was a retrospective cohort study of 25 628 patients hospitalized for exacerbation of COPD who received mechanical ventilation on the first or second hospital day at 420 US hospitals participating in the Premier Inpatient Database.

EXPOSURES

Initial ventilation strategy.

MAIN OUTCOMES AND MEASURES

In-hospital mortality, hospital-acquired pneumonia, hospital length of stay and cost, and 30-day readmission.

RESULTS

In the study population, a total of 17 978 (70%) were initially treated with NIV on hospital day 1 or 2. When compared with those initially treated with IMV, NIV-treated patients were older, had less comorbidity, and were less likely to have concomitant pneumonia present on admission. In a propensity-adjusted analysis, NIV was associated with lower risk of mortality than IMV (odds ratio [OR] 0.54; [95% CI, 0.48-0.61]). Treatment with NIV was associated with lower risk of hospital-acquired pneumonia (OR, 0.53 [95% CI, 0.44-0.64]), lower costs (ratio, 0.68 [95% CI, 0.67-0.69]), and a shorter length of stay (ratio, 0.81 [95% CI, 0.79-0.82]), but no difference in 30-day all-cause readmission (OR, 1.04 [95% CI, 0.94-1.15]) or COPD-specific readmission (OR, 1.05 [95% CI, 0.91-1.22]). Propensity matching attenuated these associations. The benefits of NIV were similar in a sample restricted to patients younger than 85 years and were attenuated among patients with higher levels of comorbidity and concomitant pneumonia. Using the hospital as an instrumental variable, the strength of association between NIV and mortality was modestly attenuated (OR, 0.66 [95% CI, 0.47-0.91]). In sensitivity analyses, the benefit of NIV was robust in the face of a strong hypothetical unmeasured confounder.

CONCLUSIONS AND RELEVANCE

In a large retrospective cohort study, patients with COPD treated with NIV at the time of hospitalization had lower inpatient mortality, shorter length of stay, and lower costs compared with those treated with IMV.

Noninvasive ventilation in acute respiratory failure

After the institution of positive-pressure ventilation, the use of noninvasive ventilation (NIV) through an interface substantially increased. The first technique was continuous positive airway pressure; but, after the introduction of pressure support ventilation at the end of the 20th century, this became the main modality. Both techniques, and some others that have been recently introduced and which integrate some technological innovations, have extensively demonstrated a faster improvement of acute respiratory failure in different patient populations, avoiding endotracheal intubation and facilitating the release of conventional invasive mechanical ventilation. In acute settings, NIV is currently the first-line treatment for moderate-to-severe chronic obstructive pulmonary disease exacerbation as well as for acute cardiogenic pulmonary edema and should be considered in immunocompromised patients with acute respiratory insufficiency, in difficult weaning, and in the prevention of postextubation failure. Alternatively, it can also be used in the postoperative period and in cases of pneumonia and asthma or as a palliative treatment. NIV is currently used in a wide range of acute settings, such as critical care and emergency departments, hospital wards, palliative or pediatric units, and in pre-hospital care. It is also used as a home care therapy in patients with chronic pulmonary or sleep disorders. The appropriate selection of patients and the adaptation to the technique are the keys to success. This review essentially analyzes the evidence of benefits of NIV in different populations with acute respiratory failure and describes the main modalities, new devices, and some practical aspects of the use of this technique.

Noninvasive Mechanical Ventilation in Patients with Severe Pneumonia

Community-acquired pneumonia (CAP)—pneumonia occurring within 48 h after hospital admission or more than 2 weeks after discharge—leads to hospitalization rates of 20–35 % in Europe, with figures in Spain being even higher at 22–61 %. A substantial proportion of these cases (10 %) are defined as severe. These patients must be admitted to the intensive care unit (ICU) because of the possible need for ventilatory or hemodynamic support. Their mortality rate can be as high as 40 % [1]. In the rest of Europe the incidence of CAP is 5–11 cases per 1,000 person-years, and in Spain it drops to 1.6–1.8 cases per 1,000 person-years, with men and the elderly most often affected and mostly in winter [1].

Complications of non-invasive ventilation techniques: a comprehensive qualitative review of randomized trials

Non-invasive ventilation (NIV) has become a common treatment for acute and chronic respiratory failure. In comparison with conventional invasive mechanical ventilation, NIV has the advantages of reducing patient discomfort, procedural complications, and mortality. However, NIV is associated with frequent uncomfortable or even life-threatening adverse effects, and patients should be thoroughly screened beforehand to reduce potential severe complications. We performed a detailed review of the relevant medical literature for NIV complications. All major NIV complications are potentially life-threatening and can occur in any patient, but are strongly correlated with the degree of pulmonary and cardiovascular involvement. Minor complications can be related to specific structural features of NIV interfaces or to variable airflow patterns. This extensive review of the literature shows that careful selection of patients and interfaces, proper setting of ventilator modalities, and close monitoring of patients from the start can greatly reduce NIV complications.

Comparative effectiveness of noninvasive ventilation vs invasive mechanical ventilation in chronic obstructive pulmonary disease patients with acute respiratory failure

BACKGROUND

Limited evidence exists on the comparative effectiveness of noninvasive ventilation (NIV) vs invasive mechanical ventilation (IMV) in acute exacerbation of chronic obstructive pulmonary disease (AECOPD) patients with respiratory failure.

OBJECTIVES

To characterize the use of NIV and IMV, and to compare the effectiveness of NIV vs IMV in AECOPD.

DESIGN AND PATIENTS

Retrospective cohort study using data from the 2006-2008 Nationwide Emergency Department Sample. Emergency department visits for AECOPD with acute respiratory failure were identified with codes from the International Classification of Diseases, Ninth Revision, Clinical Modification.

MEASURES

The outcome measures were inpatient mortality, hospital length of stay, hospital charges, and complications.

RESULTS

There were an estimated 101,000 visits annually for AECOPD with acute respiratory failure; 96% were admitted to the hospital. Of these, NIV use increased from 14% in 2006 to 16% in 2008 (P=0.049). Use of NIV, however, varied widely between hospitals, ranging from 0% to 100% with a median of 11%. Noninvasive ventilation was more often used in higher-case volume, Northeastern hospitals. In a propensity score analysis, NIV use, compared with IMV, was associated with lower inpatient mortality (risk ratio: 0.54, 95% confidence interval [CI]: 0.50-0.59), shortened hospital length of stay (-3.2 days; 95% CI: -3.4 to -2.9 days), lower hospital charges (-$35,012; 95% CI: -$36,848 to -$33,176), and lower risk of iatrogenic pneumothorax (0.05% vs 0.5%, P<0.001).

CONCLUSIONS

Although NIV use is increasing in US hospitals, its adoption remains low and varies widely between hospitals. Our observational study suggests NIV appears to be more effective and safer than IMV for AECOPD in the real-world setting.

Postoperative respiratory failure after cardiac surgery: use of noninvasive ventilation

OBJECTIVES

To analyze the use of noninvasive ventilation (NIV) in respiratory failure after extubation in patients after cardiac surgery, the factors associated with respiratory failure, and the need for reintubation.

DESIGN

Retrospective observational study.

SETTING

Intensive care unit in a university hospital.

PARTICIPANTS

Patients (n = 63) with respiratory failure after extubation after cardiac surgery over a 3-year period.

INTERVENTIONS

Mechanical NIV.

MEASUREMENTS AND MAIN RESULTS

Demographic and surgical data, respiratory history, causes of postoperative respiratory failure, durations of mechanical ventilation and spontaneous breathing, gas exchange values, and the mortality rate were recorded. Of 1,225 postsurgical patients, 63 (5.1%) underwent NIV for respiratory failure after extubation. The median time from extubation to the NIV application was 40 hours (18-96 hours). The most frequent cause of respiratory failure was lobar atelectasis (25.4%). The NIV failed in 52.4% of patients (33/63) who had a lower pH at 24 hours of treatment (7.35 v 7.42, p = 0.001) and a higher hospital mortality (51.5% v 6.7%, p = 0.001) than those in whom NIV was successful. An interval <24 hours from extubation to NIV was a predictive factor for NIV failure (odds ratio, 4.6; 95% confidence interval, 1.2-17.9), whereas obesity was associated with NIV success (odds ratio, 0.22; 95% confidence interval, 0.05-0.91).

CONCLUSIONS

Reintubation was required in half of the NIV-treated patients and was associated with an increased hospital mortality rate. Early respiratory failure after extubation (≤24 hours) is a predictive factor for NIV failure.

Women receive more trials of noninvasive ventilation for acute respiratory failure than men: a nationwide population-based study

Introduction

Previous studies in western countries have observed that women are less likely than men to receive intensive care and mechanical ventilation (MV). We aimed to investigate whether the gender difference also exists in Asian populations and in the provision of different types of MV including invasive (INV) and noninvasive ventilation (NIV).

Methods

We analyzed all adult hospital patients between 2005 and 2007 in the claims data from 1,000,000 randomly selected people in the Taiwan National Health Insurance Research Database. NIV-only was defined as patients receiving NIV as the only ventilator treatment during hospitalization. Gender difference was assessed using multivariable analyses with/without considering a hospital cluster effect by generalized estimating equations models. Subgroup analyses for gender difference in NIV use were performed using propensity score matching method.

Results

Of the 128,327 patients enrolled, 53.8% were men, 9.2% received intensive care and 5.2% used MV. After adjusting for potential confounders, women were less likely than men to receive intensive care (adjusted odds ratio [aOR] 0.77, 95% confidence interval [CI] 0.73-0.82) and MV (aOR 0.84, 95% CI 0.78-0.91). Among MV patients, 6.8% received NIV-only; the proportion of which was higher in women than in men (8.6% vs. 5.7%, P < 0.001). After controlling for confounders and a cluster effect, women remained more likely to receive NIV-only (aOR 1.61, 95% CI 1.32-1.96). Subgroup analyses showed that patients with underlying congestive heart failure (CHF) had the highest difference in the provision of NIV-only (female-to-male aOR 2.76, 95% CI 1.38-5.53). A hospital cluster effect on the gender difference in NIV use was found in patients with diseases other than chronic obstructive pulmonary disease and CHF.

Conclusions

Gender differences existed not only in the provision but also in the types of MV. Further studies are needed to understand why gender differences occur.

The utility and futility of non-invasive ventilation in non-designated areas: can critical care outreach nurses influence practice?

OBJECTIVE

To explore the practice of delivering non-invasive ventilation (NIV) in non-designated areas within a large university teaching hospital by critical care outreach nurses.

METHODS

Local audit was prospectively conducted over a five-month period of all patients commenced on NIV in non-designated areas. The audit was repeated a year later and again four years later.

MAIN OUTCOME MEASURES

Documentation of patient diagnosis and management plan including whether they were suitable for attempted cardiopulmonary resuscitation and endotracheal intubation as per British Thoracic Society guidelines (2002). Patient outcome (to hospital discharge) and arterial blood gas results pre and post commencement of NIV.

RESULTS

115 patients received NIV for the treatment of acute respiratory failure. The mortality rate for the first 2 years data combined (n75) was 57% and attributed to the fact that patients were elderly, acidotic and had diagnoses associated with a poor response to NIV. 86% of patients had a documented resuscitation status and management plan. Resuscitation status (p=0.01) and arterial blood gas improvement within two hours of therapy had a significant effect on patient outcome (p=0.001). Four years later the mortality rate had reduced to 35% possibly due to appropriate patient selection. More patients were deemed suitable for resuscitation, were transferred to designated areas and electively ventilated.

CONCLUSION

Inappropriate use of NIV in non-designated areas is associated with a high mortality. Critical care outreach nurses can play a pivotal role in influencing appropriate patient selection for NIV.

Hypercapnic encephalopathy syndrome: a new frontier for non-invasive ventilation?

According to the classical international guidelines, non-invasive ventilation is contraindicated in hypercapnic encephalopathy syndrome (HES) due to the poor compliance to ventilatory treatment of confused/agitated patients and the risk of aspirative pneumonia related to lack of airways protection. As a matter of fact, conventional mechanical ventilation has been recommended as "golden standard" in these patients. However, up to now there are not controlled data that have demonstrated in HES the advantage of conventional mechanical ventilation vs non-invasive ventilation. In fact, patients with altered mental status have been systematically excluded from the randomised and controlled trials performed with non-invasive ventilation in hypercapnic acute respiratory failure. Recent studies have clearly demonstrated that an initial cautious NPPV trial in selected HES patients may be attempt as long as there are no other contraindications and the technique is provided by experienced caregivers in a closely monitored setting where ETI is always readily available. The purpose of this review is to report the physiologic rationale, the clinical feasibility and the still open questions about the careful use of non-invasive ventilation in HES as first-line ventilatory strategy in place of conventional mechanical ventilation via endotracheal intubation.

Patient outcomes after noninvasive mechanical ventilation at a high dependency unit of an emergency department

OBJECTIVE

To describe the outcome of patients after noninvasive ventilation in a high dependency unit (HDU) of an emergency department (ED). Secondary aims were to define the role of intensive care consultation and to identify variables associated with mortality.

METHODS

Observational, prospective 6-month study.

RESULTS

Two hundred and nine cases were analysed. Thirty-four patients were initially rejected by the intensive care unit (ICU). Physicians in the ED did not request ICU consultation in the remaining 175 (83%) because of 'belief of improvable medical condition in the ED in patients without therapeutic limits' in 93 (group 1) and to 'preset therapeutic limits' or 'comfort measures only' in 82 (groups 2 and 3). Ten out of these 175 were subsequently admitted to the ICU. The global in-hospital mortality rate was 22% (3.3% in the high dependency unit), but only 10% in group 1. Place of referral for ventilation (P<0.001), absence of subsequent ventilation on the general ward (P<0.001), group of assignation (P=0.004), intensive care initial rejection (P=0.022), no previous home ventilation (P=0.028), older age (P=0.03) and longer duration on ventilation (P=0.047) were significantly associated with mortality. In the multivariate regression model, ventilating patients from general wards (odds ratio=7.1; 2.3-25, 95% confidence interval) and ventilation under preset limits (odds ratio=3.57; 1.42-8.98, 95% confidence interval) remained significantly associated with mortality.

CONCLUSION

Noninvasive ventilation is a relatively safe and effective treatment in the ED when performed in carefully controlled settings. ICU consultation may be securely deferred in this setting.

[Non-invasive ventilation]

Non-invasive ventilation (NIV) is a technique that delivers mechanical ventilation avoiding side effects and complications associated with endotracheal intubation and invasive mechanical ventilation. This technique has proved to be effective in different types of respiratory failure. In this article, the authors revise the advantages and limitations of NIV, interfaces used and indications in acute and acute-on-chronic respiratory failure.