Noninvasive mechanical ventilation in acute respiratory failure: trends in use and outcomes

The effects of noninvasive respiratory support on swallowing physiology, airway protection, and respiratory-swallow pattern in adults: A systematic review

PURPOSE

The use of noninvasive respiratory support- namely high flow of oxygen delivered via nasal cannula (HFNC), continuous positive airway pressure (CPAP), and noninvasive ventilation (NIV) - has been expanding in recent years. The physiologic mechanisms underlying each of these forms of support are generally well understood. In contrast, the effects on the sensorimotor mechanisms of swallowing movements, and of breathing and swallowing coordination ─ critical elements of airway protection and bolus clearance ─ remain unclear. The purpose of this systematic review is to assess the existing evidence about the impact of noninvasive respiratory support on swallowing mechanics, airway protection, and respiratory-swallowing patterns in adults.

METHODS

Six databases (PubMed, EMBASE, Web of Science, Scopus, CINAHL and ProQuest Dissertations & Theses) were searched using predetermined terms. Inclusion criteria were: 1) adult humans 2) use of noninvasive respiratory support, and 3) assessment of swallowing.

RESULTS

We identified 8727 articles for screening; 15 met the inclusion criteria. Six studies assessed noninvasive respiratory support in healthy adults, and 9 assessed participants with heterogenous respiratory diagnoses including chronic obstructive pulmonary disease (COPD), obstructive sleep apnea (OSA), acute respiratory failure, and chronic respiratory failure due to neuromuscular disease. Risk of bias was assessed using a modified NIH Quality Assessment Tool. In healthy adults, results demonstrated mixed effects of HFNC and CPAP on measures of swallowing function, airway protection, and respiratory swallowing patterns. Negative effects on respiratory-swallowing patterns were reported with NIV. In adults with heterogeneous respiratory diagnoses, six studies reported that HFNC, CPAP, or nasal NIV improved measures of swallowing and respiratory-swallowing patterns. HFNC has mixed effects on swallowing measures in ICU patients. NIV increased atypical respiratory-swallowing patterns in patients with stable COPD.

CONCLUSIONS

Due to small sample sizes and the wide variation in study designs, the impact of noninvasive respiratory support on swallowing, airway protection, and respiratory-swallowing patterns cannot be confidently assessed based on the current evidence. Future studies using standardized, validated, and reproducible methods to assess the impact of noninvasive respiratory support on swallowing physiology and airway protection are warranted.

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.

Non-Invasive Ventilation for Community-Acquired Pneumonia: Outcomes and Predictors of Failure from an ICU Cohort

Background and Objectives: The use of non-invasive ventilation (NIV) for community-acquired pneumonia (CAP) remains controversial. NIV failure in the setting of acute hypoxemic respiratory failure is associated with increased mortality, highlighting the need for careful patient selection. Methods and Methods: This is a retrospective observational cohort study. We included 140 patients with severe CAP, treated with either NIV or invasive mechanical ventilation (IMV) as their primary oxygenation strategy. Results: The median PaO2/FiO2 ratio and SOFA score upon ICU admission were 151 mmHg and 6, respectively. We managed 76% of patients with NIV initially and report an NIV success rate of 59%. Overall, the 28-day mortality was 25%, whilst for patients with NIV success, the mortality was significantly lower at 13%. In the univariate analysis, NIV failure was associated with the SOFA score (OR 1.33), the HACOR score (OR 1.14) and the presence of septic shock (OR 3.99). The SOFA score has an AUC of 0.75 for NIV failure upon ICU admission, whilst HACOR has an AUC of 0.76 after 2 h of NIV. Conclusions: Our results suggest that a SOFA ≤ 4 and an HACOR ≤ 5 are reasonable thresholds to identify patients with severe CAP likely to benefit from NIV.

The Impact of High-Flow Nasal Cannula Therapy on Acute Respiratory Distress Syndrome Patients: A Systematic Review

High-flow nasal cannula (HFNC) is a novel oxygenation approach in the management of acute respiratory distress syndrome (ARDS). This systematic review was focused on evaluating current evidence concerning the efficacy of HFNC in ARDS and its comparison with standard treatment approaches. For this review, a systematic search was undertaken in PubMed, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Embase, Web of Science, Cochrane Library, and Google Scholar to identify relevant studies. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. All those studies that investigated the impact of HFNC on ARDS patients and were published in the English language were included. The literature search from all databases provided 6157 potentially relevant articles from PubMed (n = 1105), CINAHL (n = 808), Web of Science (n = 811), Embase (n = 2503), Cochrane database (n = 930), and Google Scholar (n = 46). After the exclusion of studies that did not fulfill the criteria, 18 studies were shortlisted for the scope of this systematic review. Among the included studies, five focused on HFNC's impact on COVID-19-related ARDS, whereas 13 studies focused on HFNC's impact on ARDS patients. Most studies demonstrated the efficacy of HFNC in managing ARDS, with some studies showing comparable efficacy and higher safety compared to noninvasive ventilation (NIV). This systematic review highlights the potential benefits of HFNC in ARDS management. The findings show that HFNC is effective in reducing the respiratory distress symptoms, the incidence of invasive ventilation, and the adverse events associated with ARDS. These findings can help clinical decision-making processes and contribute to the evidence base for optimal ARDS management strategies.

Trends in mortality in septic patients according to the different organ failure during 15 years

Background

The incidence of sepsis can be estimated between 250 and 500 cases/100.000 people per year and is responsible for up to 6% of total hospital admissions. Identified as one of the most relevant global health problems, sepsis is the condition that generates the highest costs in the healthcare system. Important changes in the management of septic patients have been included in recent years; however, there is no information about how changes in the management of sepsis-associated organ failure have contributed to reduce mortality.

Methods

A retrospective analysis was conducted from hospital discharge records from the Minimum Basic Data Set Acute-Care Hospitals (CMBD-HA in Catalan language) for the Catalan Health System (CatSalut). CMBD-HA is a mandatory population-based register of admissions to all public and private acute-care hospitals in Catalonia. Sepsis was defined by the presence of infection and at least one organ dysfunction. Patients hospitalized with sepsis were detected, according ICD-9-CM (since 2005 to 2017) and ICD-10-CM (2018 and 2019) codes used to identify acute organ dysfunction and infectious processes.

Results

Of 11.916.974 discharges from all acute-care hospitals during the study period (2005–2019), 296.554 had sepsis (2.49%). The mean annual sepsis incidence in the population was 264.1 per 100.000 inhabitants/year, and it increased every year, going from 144.5 in 2005 to 410.1 in 2019. Multiorgan failure was present in 21.9% and bacteremia in 26.3% of cases. Renal was the most frequent organ failure (56.8%), followed by cardiovascular (24.2%). Hospital mortality during the study period was 19.5%, but decreases continuously from 25.7% in 2005 to 17.9% in 2019 (p < 0.0001). The most important reduction in mortality was observed in cases with cardiovascular failure (from 47.3% in 2005 to 31.2% in 2019) (p < 0.0001). In the same way, mean mortality related to renal and respiratory failure in sepsis was decreased in last years (p < 0.0001).

Conclusions

The incidence of sepsis has been increasing in recent years in our country. However, hospital mortality has been significantly reduced. In septic patients, all organ failures except liver have shown a statistically significant reduction on associated mortality, with cardiovascular failure as the most relevant.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-04176-w.

Factors and Outcomes Associated with Failed Noninvasive Positive Pressure Ventilation in Patients with Acute Respiratory Failure

Background

The decision guild for non-invasive positive pressure ventilation (NPPV) application in acute respiratory failure (ARF) patients still needs to work out.

Methods

Adult patients with acute hypoxemic or hypercapnic respiratory failure were recruited and treated with NPPV or primary invasive mechanical ventilation (IMV). Patients’ characteristic and clinical outcomes were recorded. Logistic regression models were used to estimate the adjusted odds ratio (aOR) and 95% confidence intervals for baseline characteristics and clinical outcomes. Subgroup analyses by reason behind successful NPPV were conducted to ascertain if any difference could influence the outcome.

Results

A total of 4525 ARF patients were recruited in our facility between year 2015 and 2017. After exclusion, 844 IMV patients, 66 patients with failed NPPV, and 74 patients with successful NPPV were enrolled. Statistical analysis showed APACHE II score (aOR = 0.93), time between admission and start NPPV (aOR = 0.92), and P/F ratio (aOR = 1.04) were associated with successful NPPV. When comparing with IMV patients, failed NPPV patients displayed a significantly lower APACHE II score, higher Glasgow Coma Scale, longer length of stay in hospital, longer duration of invasive ventilation, RCW/Home ventilator, and some comorbidities.

Conclusion

APACHE II score, time between admission and start NPPV, and PaO2 can be predictors for successful NPPV. The decision of NPPV application is critical as ARF patients with failed NPPV have various worse outcomes than patients receiving primary IMV.

Improving mobility in the intensive care unit with a protocolized, early mobilization program: observations of a single center before-and-after the implementation of a multidisciplinary program

Background

Early intensive care unit (ICU) protocolized rehabilitative programs have been described previously, yet with differing starting time points and mostly on mechanically ventilated patients. We extended the concept to all admitted ICU patients and investigate the efficacy of early mobilization in improving mobility of the critically ill, address issues surrounding the timing and intensity of an early rehabilitative program.

Methods

Prospective cohorts of patients admitted consecutively before-and-after (control, n=92; intervention, n=90) the introduction of an early mobilization program in a single center, general hospital ICU. Improvement in mobility as assessed by ICU mobility score, on ICU admission and upon ICU discharge, was measured as a primary outcome.

Results

Those receiving early mobilization in the intensive care unit had higher ICU mobility score (2.63; 95% confidence interval, 0.65–4.61; P<0.001) upon discharge from the intensive care, with earlier out of bed mobilization on day 5 compared to the control group of day 21 (P<0.001). No differences were found in terms of mortality, intensive care hospitalization and subsequent hospitalization duration after discharge from ICU.

Conclusions

Here, we report that improvement in mobility score earlier in the course of intensive care hospitalization with the introduction of a protocolized early rehabilitative program.

Non-Invasive Ventilation as a Therapy Option for Acute Exacerbations of Chronic Obstructive Pulmonary Disease and Acute Cardiopulmonary Oedema in Emergency Medical Services

In this observational prospective multicenter study conducted between October 2016 and October 2018, we tested the hypothesis that the use of prehospital non-invasive ventilation (phNIV) to treat patients with acute respiratory insufficiency (ARI) caused by severe acute exacerbations of chronic obstructive pulmonary disease (AECOPD) and acute cardiopulmonary oedema (ACPE) is effective, time-efficient and safe. The data were collected at four different physician response units and three admitting hospitals in a German EMS system. Patients with respiratory failure due to acute exacerbation of chronic obstructive pulmonary disease and acute cardiopulmonary oedema were enrolled. A total of 545 patients were eligible for the final analysis. Patients were treated with oxygen supplementation, non-invasive ventilation or invasive mechanical ventilation. The primary outcomes were defined as changes in the clinical parameters and the in-hospital course. The secondary outcomes included time efficiency, peri-interventional complications, treatment failure rate, and side-effects. Oxygenation under phNIV improved equally to endotracheal intubation (ETI), and more effectively in comparison to standard oxygen therapy (SOT) (paO2 SOT vs. non-invasive ventilation (NIV) vs. ETI: 82 mmHg vs. 125 mmHg vs. 135 mmHg, p-value SOT vs. NIV < 0.0001). In a matched subgroup analysis phNIV was accompanied by a reduced time of mechanical ventilation (phNIV: 1.8 d vs. ETI: 4.2 d) and a shortened length of stay at the intensive care unit (3.4 d vs. 5.8 d). The data support the hypothesis that the treatment of severe AECOPD/ACPE-induced ARI using prehospital NIV is effective, time efficient and safe. Compared to ETI, a matched comparison supports the hypothesis that prehospital implementation of NIV may provide benefits for an in-hospital course.

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.

Noninvasive respiratory support following extubation in critically ill adults: a systematic review and network meta-analysis

PURPOSE

Systematic review and network meta-analysis to investigate the efficacy of noninvasive respiratory strategies, including noninvasive positive pressure ventilation (NIPPV) and high-flow nasal cannula (HFNC), in reducing extubation failure among critically ill adults.

METHODS

We searched databases from inception through October 2021 for randomized controlled trials (RCTs) evaluating noninvasive respiratory support therapies (NIPPV, HFNC, conventional oxygen therapy, or a combination of these) following extubation in critically ill adults. Two reviewers performed screening, full text review, and extraction independently. The primary outcome of interest was reintubation. We used GRADE to rate the certainty of our findings.

RESULTS

We included 36 RCTs (6806 patients). Compared to conventional oxygen therapy, NIPPV (OR 0.65 [95% CI 0.52-0.82]) and HFNC (OR 0.63 [95% CI 0.45-0.87]) reduced reintubation (both moderate certainty). Sensitivity analyses showed that the magnitude of the effect was highest in patients with increased baseline risk of reintubation. As compared to HFNC, no difference in incidence of reintubation was seen with NIPPV (OR 1.04 [95% CI 0.78-1.38], low certainty). Compared to conventional oxygen therapy, neither NIPPV (OR 0.8 [95% CI 0.61-1.04], moderate certainty) or HFNC (OR 0.9 [95% CI 0.66-1.24], low certainty) reduced short-term mortality. Consistent findings were demonstrated across multiple subgroups, including high- and low-risk patients. These results were replicated when evaluating noninvasive strategies for prevention (prophylaxis), but not in rescue (application only after evidence of deterioration) situations.

CONCLUSIONS

Our findings suggest that both NIPPV and HFNC reduced reintubation in critically ill adults, compared to conventional oxygen therapy. NIPPV did not reduce incidence of reintubation when compared to HFNC. These findings support the preventative application of noninvasive respiratory support strategies to mitigate extubation failure in critically ill adults, but not in rescue conditions.

Evidence-Based Mechanical Ventilatory Strategies in ARDS

Acute respiratory distress syndrome (ARDS) remains one of the leading causes of morbidity and mortality in critically ill patients despite advancements in the field. Mechanical ventilatory strategies are a vital component of ARDS management to prevent secondary lung injury and improve patient outcomes. Multiple strategies including utilization of low tidal volumes, targeting low plateau pressures to minimize barotrauma, using low FiO₂ (fraction of inspired oxygen) to prevent injury related to oxygen free radicals, optimization of positive end expiratory pressure (PEEP) to maintain or improve lung recruitment, and utilization of prone ventilation have been shown to decrease morbidity and mortality. The role of other mechanical ventilatory strategies like non-invasive ventilation, recruitment maneuvers, esophageal pressure monitoring, determination of optimal PEEP, and appropriate patient selection for extracorporeal support is not clear. In this article, we review evidence-based mechanical ventilatory strategies and ventilatory adjuncts for ARDS.

Association of Non-Invasive Positive Pressure Ventilation with Short-Term Clinical Outcomes in Patients Hospitalized for Acute Decompensated Heart Failure

The real-world evidence has been sparse on the impact of non-invasive positive pressure ventilation (NPPV) on the outcomes in acute decompensated heart failure (ADHF) patients. We aim to explore this issue in the prospective multicenter WET-HF registry. Among 3927 patients (77 (67–84) years, male 60%), the NPPV was used in 775 patients (19.7%). The association of NPPV use with in-hospital outcome and length of hospital stay (LOS) was examined by two methods, propensity score (PS) matching and multivariable analysis with adjustment for PS. In these analyses the NPPV group exhibited a lower endotracheal intubation (ETI) rate and a comparable in-hospital mortality, but longer LOS compared to the non-NPPV group. In the stratified analysis, the NPPV group exhibited a significantly lower ETI rate in patients with ischemic etiology, systolic blood pressure (sBP) > 140 mmHg and the Controlling Nutritional Status (CONUT) score ≤ 3, indicating better nutritional status. On the contrary, NPPV use was associated with longer LOS in patients with non-ischemic etiology, sBP < 100 mmHg and CONUT score > 3. In conclusion, NPPV use was associated with a lower incidence of ETI. Particularly, patients with ischemic etiology, high sBP, and better nutritional status might benefit from NPPV use.

Enhancing Implementation of Complex Critical Care Interventions through Interprofessional Education

Background: Many critical care interventions that require teamwork are adopted slowly and variably despite strong evidence supporting their use. We hypothesize that educational interventions that target the entire interprofessional team (rather than professions in isolation) are one effective way to enhance implementation of complex interventions in the intensive care unit (ICU). Objective: As a first step toward testing this hypothesis, we sought to qualitatively solicit opinions about team dynamics, evidence translation, and interprofessional education as well as current knowledge, attitudes, and practices surrounding the use of one example of a team-based practice in the ICU-preventive postextubation noninvasive ventilation (NIV). Methods: We conducted a qualitative evaluation using semistructured interviews and focus groups with nurses, respiratory therapists, and physicians working in four ICUs in four hospitals within an integrated health system. ICUs were selected based on variation in academic versus community status. We iteratively analyzed transcripts using a thematic content analysis approach. Results: From December 2018 to January 2019, we conducted 32 interviews (34 people) and 3 focus groups (20 people). Participants included 31 nurses, 15 respiratory therapists, and 8 physicians. Participants had favorable views of how their teams work together but discussed ways team dynamics (e.g., leader inclusiveness) impact care coordination. Participants viewed interprofessional education favorably and shared suggestions regarding preferred content and delivery (e.g., include both profession-specific and team-oriented content). Though participants reported frequently using NIV as a treatment, they described rarely using NIV as a preventive strategy, and nurses and respiratory therapists described challenges to use such as perceived patient discomfort. There were ICU-specific differences in management of patients at a high risk for respiratory failure after extubation, with some preferring to delay extubation. Conclusion: Participants reported optimism that interprofessional education can be an acceptable and effective way to improve translation of evidence into practice. Participants also detailed patient-specific and ICU-wide barriers to the implementation of preventive postextubation NIV. This information about teamwork in the ICU, suggestions for interprofessional education, and barriers and facilitators to use of a target evidence-based practice can inform the development of novel educational strategies in ways that increase acceptability, appropriateness, and feasibility of the intervention.

Outcomes and Resource Use Associated With Acute Respiratory Failure in Safety Net Hospitals Across the United States

BACKGROUND

Despite the frequency and cost of hospitalizations for acute respiratory failure (ARF), the literature regarding the impact of hospital safety net burden on outcomes of these hospitalizations is sparse.

RESEARCH QUESTION

How does safety net burden impact outcomes of ARF hospitalizations such as mortality, tracheostomy, and resource use?

STUDY DESIGN AND METHODS

This was a retrospective cohort study using the National Inpatient Sample 2007-2017. All patients hospitalized with a primary diagnosis of ARF were tabulated using the International Classification of Diseases 9th and 10th Revision codes, and safety net burden was calculated using previously published methodology. High- and low-burden hospitals were generated from proportions of Medicaid and uninsured patients. Trends were analyzed using a nonparametric rank-based test, whereas multivariate logistic and linear regression models were used to establish associations of safety net burden with key clinical outcomes.

RESULTS

Of an estimated 8,941,334 hospitalizations with a primary diagnosis of ARF, 33.9% were categorized as occurring at low-burden hospitals (LBHs) and 31.6% were categorized as occurring at high-burden hospitals (HBHs). In-hospital mortality significantly decreased at HBHs (22.8%-12.6%; nonparametric trend [nptrend] < .001) and LBHs (22.0%-10.9%; nptrend < .001) over the study period, as did tracheostomy placement (HBH, 5.6%-1.3%; LBH, 3.5%-0.8%; all nptrend <.001). After adjustment for patient and hospital factors, an HBH was associated with increased odds of mortality (adjusted OR [AOR], 1.11; 95% CI, 1.10-1.12) and tracheostomy use (AOR, 1.33; 95% CI, 1.29-1.37), as well as greater hospitalization costs (β coefficient, +$1,083; 95% CI, $882-$1,294) and longer lengths of stay (β coefficient, +3.3 days; 95% CI, 3.2-3.3 days).

INTERPRETATION

After accounting for differences between patient cohorts, high safety net burden was associated independently with inferior clinical outcomes and increased costs after ARF hospitalizations. These findings emphasize the need for health care reform to ameliorate disparities within these safety net centers, which treat our most vulnerable populations.

Association Between Early Invasive Mechanical Ventilation and Day-60 Mortality in Acute Hypoxemic Respiratory Failure Related to Coronavirus Disease-2019 Pneumonia

Supplemental Digital Content is available in the text.

Objectives:

About 5% of patients with coronavirus disease-2019 are admitted to the ICU for acute hypoxemic respiratory failure. Opinions differ on whether invasive mechanical ventilation should be used as first-line therapy over noninvasive oxygen support. The aim of the study was to assess the effect of early invasive mechanical ventilation in coronavirus disease-2019 with acute hypoxemic respiratory failure on day-60 mortality.

Design:

Multicenter prospective French observational study.

Setting:

Eleven ICUs of the French OutcomeRea network.

Patients:

Coronavirus disease-2019 patients with acute hypoxemic respiratory failure (Pao₂/Fio₂ ≤ 300 mm Hg), without shock or neurologic failure on ICU admission, and not referred from another ICU or intermediate care unit were included.

Intervention:

We compared day-60 mortality in patients who were on invasive mechanical ventilation within the first 2 calendar days of the ICU stay (early invasive mechanical ventilation group) and those who were not (nonearly invasive mechanical ventilation group). We used a Cox proportional-hazard model weighted by inverse probability of early invasive mechanical ventilation to determine the risk of death at day 60.

Measurement and Main Results:

The 245 patients included had a median (interquartile range) age of 61 years (52–69 yr), a Simplified Acute Physiology Score II score of 34 mm Hg (26–44 mm Hg), and a Pao₂/Fio₂ of 121 mm Hg (90–174 mm Hg). The rates of ICU-acquired pneumonia, bacteremia, and the ICU length of stay were significantly higher in the early (n = 117 [48%]) than in the nonearly invasive mechanical ventilation group (n = 128 [52%]), p < 0.01. Day-60 mortality was 42.7% and 21.9% in the early and nonearly invasive mechanical ventilation groups, respectively. The weighted model showed that early invasive mechanical ventilation increased the risk for day-60 mortality (weighted hazard ratio =1.74; 95% CI, 1.07–2.83, p=0.03).

Conclusions:

In ICU patients admitted with coronavirus disease-2019-induced acute hypoxemic respiratory failure, early invasive mechanical ventilation was associated with an increased risk of day-60 mortality. This result needs to be confirmed.

Low-Cost, Open-Source Mechanical Ventilator with Pulmonary Monitoring for COVID-19 Patients

This paper shows the construction of a low-cost, open-source mechanical ventilator. The motivation for constructing this kind of ventilator comes from the worldwide shortage of mechanical ventilators for treating COVID-19 patients—the COVID-19 pandemic has been striking hard in some regions, especially the deprived ones. Constructing a low-cost, open-source mechanical ventilator aims to mitigate the effects of this shortage on those regions. The equipment documented here employs commercial spare parts only. This paper also shows a numerical method for monitoring the patients’ pulmonary condition. The method considers pressure measurements from the inspiratory limb and alerts clinicians in real-time whether the patient is under a healthy or unhealthy situation. Experiments carried out in the laboratory that had emulated healthy and unhealthy patients illustrate the potential benefits of the derived mechanical ventilator.

Non-invasive ventilation indication for critically ill cancer patients admitted to the intensive care unit for acute respiratory failure (ARF) with associated cardiac dysfunction: Results from an observational study

Background

Acute respiratory failure (ARF) is a life-threatening complication in onco-hematology patients. Optimal ventilation strategy in immunocompromised patients has been highly controversial over the last decade. Data are lacking on patients presenting with ARF associating isolated cardiac dysfunction or in combination with another etiology. The aim of this study was to assess prognostic impact of initial ventilation strategy in onco-hematology patients presenting ARF with associated cardiac dysfunction.

Methods

We conducted an observational retrospective study in Institut Paoli-Calmettes, a cancer-referral center, assessing all critically ill cancer patients admitted to the ICU for a ARF with cardiac dysfunction.

Results

Between 2010–2017, 127 patients were admitted. ICU and hospital mortality were 29% and 57%. Initial ventilation strategy was invasive mechanical ventilation (MV) in 21%. Others ventilation strategies were noninvasive ventilation (NIV) in 50%, associated with oxygen in 21% and high flow nasal oxygen (HFNO) in 29%, HFNO alone in 6% and standard oxygen in 23%. During ICU stay, 48% of patients required intubation. Multivariate analysis identified 3 independent factors associated with ICU mortality: SAPSII at admission (OR = 1.07/point, 95%CI = 1.03–1.11, p<0.001), invasive fungal infection (OR = 7.65, 95%CI = 1.7–34.6, p = 0.008) and initial ventilation strategy (p = 0.015). Compared to NIV, HFNO alone and standard oxygen alone were associated with an increased ICU mortality, with respective OR of 19.56 (p = 0.01) and 10.72 (p = 0.01). We realized a propensity score analysis including 40 matched patients, 20 in the NIV arm and 20 receiving others ventilation strategies, excluding initial MV patients. ICU mortality was lower in patients treated with NIV (10%), versus 50% in the other arm (p = 0.037).

Conclusion

In onco-hematology patients admitted for ARF with associated cardiac dysfunction, severity at ICU admission, invasive fungal infections and initial ventilation strategy were independently associated with ICU mortality. NIV was a protective factor on ICU mortality.

Noninvasive Ventilation for Critically Ill Subjects With Acute Respiratory Failure in the Emergency Department

BACKGROUND

We aimed to investigate the association between noninvasive ventilation (NIV) initiated in the emergency department and patient outcomes for those requiring invasive mechanical ventilation so that we could understand the effect of extended NIV use (ie, > 4 h) prior to invasive mechanical ventilation on patient outcomes.

METHODS

We conducted a retrospective single-center cohort study at an academic tertiary care hospital center. All emergency department patients with acute respiratory failure requiring invasive mechanical ventilation and admission to the ICU within 48 h of initial presentation over a 24-month period were included.

RESULTS

Subject characteristics, ventilator parameters, and clinical course were captured via electronic query, respiratory billing data, and standardized chart abstraction. A total of 431 subjects with acute respiratory failure requiring invasive mechanical ventilation within 48 h of arrival were identified, of whom 115 (26.7%) were exposed to NIV prior to invasive mechanical ventilation, with a median duration of 4 h (interquartile range 1.9-9.3). Based on a multivariable model controlling for covariates, any NIV exposure prior to invasive mechanical ventilation was not associated with an increased odds of persistent organ dysfunction or death. However, in the subset of subjects exposed to NIV, extended NIV use (ie, > 4 h) prior to invasive mechanical ventilation was associated with increased odds of persistent organ dysfunction or death (odds ratio 4.11, 95% CI 1.51-11.19). Extended NIV use was also associated with increased odds of in-hospital mortality (odds ratio 4.02, 95% CI 1.51-10.74).

CONCLUSIONS

Although any exposure to NIV prior to invasive mechanical ventilation did not appear to affect morbidity and mortality, extended NIV use prior to invasive mechanical ventilation was associated with worse patient outcomes, suggesting a need for additional study to better understand the ramifications of duration of NIV use prior to failure on outcomes. Given this early timeframe for intervention, future studies should be collaborations between the emergency department and ICU.

Noninvasive Positive Pressure Ventilation in Patients with Acute Respiratory Failure Secondary to Acute Exacerbation of Chronic Obstructive Pulmonary Disease

Introduction

Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is a leading cause of poor quality of life and mortality in developing countries. Noninvasive positive pressure ventilation (NIPPV) remains the first-line intervention in hospitalized patients with acute respiratory failure (ARF) due to AECOPD. However, NIPPV may fail in some patients. This study was conducted to assess the frequency of NIPPV failure and clinical parameters and outcomes in AECOPD patients with failed NIPPV and their conversion to invasive positive pressure ventilation (IPPV).

Methods

This prospective observational study was conducted in the pulmonology unit of a tertiary care hospital in Pakistan. AECOPD patients with ARF who were candidates of NIPPV were included after securing informed consent. Their demographic characteristics, clinical parameters, and in-hospital outcomes were recorded on a semi-structured proforma. For statistical analysis, SPSS software version 22.0 for Windows (IBM, Armonk, NY) was used.

Results

With 24 hours of NIPPV, 73 (70.2%) patients improved and the remaining 31 (29.8%) were shifted to IPPV. Patients in the IPPV group had higher systolic blood pressure (BP) [133.8 mmHg (±21.2) vs. 121.1 mmHg (±8.3); probability value (p): <0.000] and lower diastolic BP [68.7 mmHg (±13.4) vs. 76.2 mmHg (±10.8); p: 0.003]. Their pH was more acidic [7.20 (±0.13) vs. 7.42 (±0.01); p: <0.000], heart rates were high [131.1 (±10.5) vs. 100.2 (±7.5); p: <0.000], and the percentage of oxygen saturation was low [90.7 (±3.0) vs. 93.4 (±4.5); p: 0.004]. Patients who were managed on NIPPV throughout their hospital stay required respiratory support for fewer days [3.2 (±1.3) vs. 4.1 (±1.8); p: 0.005], and their hospital stay was shorter [3.5 (±1.2) vs. 5.3 (±2.5) days; p: <0.000]. Mortality rate in the NIPPV group was significantly lower (1.4% vs. 12.9%; p: 0.01).

Conclusions

Deranged blood pressure, increased heart rate, acidemia, and a low percentage of oxygen saturation are crucial clinical and biochemical parameters that can predict the success of NIPPV with 24 hours of therapy in patients with AECOPD and secondary ARF. Patients who do not improve with 24 hours of NIPPV therapy usually have poor in-hospital outcomes including mortality.

Targeting Notch-activated M1 macrophages attenuate lung tissue damage in a rat model of ventilator induced lung injury

Ventilator induced lung injury (VILI) may be involved in the activation of alveolar macrophages. The purpose of this study was to investigate the relationship between the Notch signaling pathway and macrophage polarization in VILI. The VILI model was established using rats. Hematoxylineosin staining was used to test the lung tissue morphology. Bicinchoninic acid assay and ELISA were performed to detect protein and tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-10 levels in bronchoalveolar lavage fluids (BALF), respectively. The ratio of alveolar M1 and M2 macrophages was detected by flow cytometry. The mRNA and protein expression levels of Notch pathway-related proteins were determined using reverse transcription-quantitative PCR and western blotting. The present study found that high-frequency mechanical ventilation could cause pulmonary edema and increase the levels of protein, TNF-α and IL-6 in BALF while decreasing the level of IL-10 in BALF. High-frequency mechanical ventilation also induced polarization of alveolar macrophages to M1. The results also showed a significant increase in the levels of Notch pathway-related proteins including notch intracellular domain, Hes1, Hes5 and Hey1. Injection of N-[N-(3,5-difluorophenylacetyl)-1-alanyl] phenylglycine t-butyl ester could inhibit the Notch pathway and such an inhibition protected lung tissue and reduced lung inflammation caused by mechanical ventilation. After the Notch pathway was inhibited, the level of M1 polarization of macrophages caused by high-frequency mechanical ventilation was reduced. VILI caused pulmonary inflammation and macrophages to polarize to M1 and upregulated the expression levels of Notch pathway-related proteins. The inhibition of Notch pathway also reduced the proportion of M1 macrophages and inflammatory responses.

Mechanical Ventilation Strategies for the Patient with Severe Obstructive Lung Disease

Patients with respiratory failure due to obstructive lung disease present a challenge to the emergency physician. These patients have physiologic abnormalities that prevent adequate gas exchange and lung mechanics which render them at increased risk of cardiopulmonary decompensation when managed with invasive mechanical ventilation. This article addresses key principles when managing these challenging patients: patient-ventilator synchrony, air trapping and auto-positive end-expiratory pressure, and airway pressures. This article provides a practical workflow for the emergency physician responsible for managing these patients.

Current Status of Noninvasive Ventilation Use in Korean Intensive Care Units: A Prospective Multicenter Observational Study

Background

Data on noninvasive ventilation (NIV) use in intensive care units (ICUs) are very limited in South Korea.

Methods

A prospective observational study was performed in 20 ICUs of university-affiliated hospitals from June 2017 to February 2018. Adult patients (age>18 years) who were admitted to the ICU and received NIV treatment for acute respiratory failure were included.

Results

A total of 156 patients treated with NIV were enrolled (mean age, 71.9±11.6 years). The most common indications for NIV were acute hypercapnic respiratory failure (AHRF, n=89) and post-extubation respiratory failure (n=44). The main device for NIV was an invasive mechanical ventilator with an NIV module (61.5%), and the majority of patients (87.2%) used an oronasal mask. After the exclusion of 32 do-not-resuscitate patients, NIV success rate was 68.5% (85/124); ICU and hospital mortality rates were 8.9% and 15.3%, respectively. However, the success rate was lower in patients with de novo respiratory failure (27.3%) compared to that of patients with AHRF (72.8%) or post-extubation respiratory failure (75.0%). In multivariate analysis, immunocompromised state, de novo respiratory failure, post-NIV (2 hours) respiratory rate, NIV mode (i.e., non-pressure support ventilation mode), and the change of NIV device were significantly associated with a lower success rate of NIV.

Conclusion

AHRF and post-extubation respiratory failure were the most common indications for NIV in Korean ICUs. Overall NIV success was achieved in 68.5% of patients, with the lowest rate in patients with de novo respiratory failure.

An observational study on the practice of noninvasive ventilation at a tertiary level Australian intensive care unit

BACKGROUND

Failure of Non-Invasive Ventilation (NIV) is associated with increased morbidity and mortality among critically ill patients. Although there is evidence of association between disease related factors and NIV failure, it is unclear whether factors related to NIV application contribute to NIV failure.

OBJECTIVES

To evaluate NIV failure rate and factors associated with NIV failure.

DESIGN, SETTINGS AND OUTCOMES

Prospective, observational, pilot study conducted in a 23-bed, tertiary care Intensive Care Unit (ICU). NIV failure was defined as application of NIV resulting in intubation or death in ICU.

RESULTS

Amongst 238 patients admitted with respiratory failure, NIV was administered to 60 patients (34 males, 26 females) for a total of 70 application episodes. The etiology of respiratory failure included acute pulmonary edema (28.6%), acute lung injury (22.9%) and pneumonia (15.7%). The mean (SD) age was 62 (17.6) years, BMI 32.0 (8.5) kg/m² and median APACHE-II score 17.5 (14.0-23.8). NIV failure occurred in 22 out of 70 applications (31.4% [95%CI 20.0-43.0]). NIV failure assessed by simple logistic regression analysis, was associated with admission diagnosis (OR 6.0, 95%CI: 1.3-28.7, p = 0.03), use of bi-level NIV-PS (OR 5.00, 95%CI: 1.04-24.1, p = 0.04), presence of nasogastric tube (OR 6.20, 95%CI: 1.9-19.8, p < 0.01) and with short NIV breaks in the 2nd 24-hours (OR 0.96, 95%CI: 0.91-0.99, p = 0.04).

CONCLUSION

NIV failure was observed in 31.4%. Factors associated with NIV failure were etiology of respiratory illness, type of NIV support and short NIV breaks, presumably reflecting illness severity or progress of disease. The presence of a nasogastric tube during application of NIV may adversely impact NIV application.

Management of Acute Respiratory Failure Due to Community-Acquired Pneumonia: A Systematic Review

Community-acquired pneumonia (CAP) is a leading cause of mortality worldwide. CAP mortality is driven by the development of sepsis and acute respiratory failure (ARF). We performed a systematic review of the available English literature published in the period 1 January 1997 to 31 August 2017 and focused on ARF in CAP. The database searches identified 189 articles—of these, only 29 were retained for data extraction. Of these 29 articles, 12 addressed ARF in CAP without discussing its ventilatory management, while 17 evaluated the ventilatory management of ARF in CAP. In the studies assessing the ventilatory management, the specific treatments addressed were: high-flow nasal cannula (HFNC) (n = 1), continuous positive airway pressure (n = 2), non-invasive ventilation (n = 9), and invasive mechanical ventilation (n = 5). When analyzed, non-invasive ventilation (NIV) success rates ranged from 20% to 76% and they strongly predicted survival, while NIV failure led to an increased risk of adverse outcome. In conclusion, ARF in CAP patients may require both ventilatory and non-ventilatory management. Further research is needed to better evaluate the use of NIV and HFNC in those patients. Alongside the prompt administration of antimicrobials, the potential use of steroids and the implementation of severity scores should also be considered.

Noninvasive Ventilation and Oxygen Therapy after Extubation in Patients with Acute Respiratory Failure: A Meta-analysis of Randomized Controlled Trials

Background

Role of noninvasive ventilation (NIV) following extubation in patients with acute respiratory failure is debatable. NIV may provide benefit in post surgical patients, but its role in nonsurgical patients is controversial.

Materials and methods

PubMed and Cochrane Central Register of Controlled Trials (CENTRAL) were searched (from 1946 to 20^th November 2017) to identify prospective randomized controlled trials, where postextubation NIV has been compared with standard oxygen therapy in adult patients with acute respiratory failure.

Results

Data of 1525 patients from 11 randomized trials have been included in this meta-analysis. Two trials used NIV to manage post-extubation respiratory failure. Pooled analysis found that mortality rate at longest available follow-up [OR (95% CI) 0.84 (0.50, 1.42); p = 0.52] and reintubation rate [OR (95% CI) 0.75 (0.51, 1.09); p = 0.13] were similar between NIV and standard oxygen therapy. NIV did not decrease intubation rate when used as preventive modality [OR (95% CI) 0.65 (0.40, 1.06); p = 0.08]. Duration of ICU stay was also similar in the two groups [MD (95% CI) 0.46 (-0.43, 1.36) days; p = 0.3].

Conclusion

Post extubation NIV in non- surgical patients with acute respiratory failure does not provide any benefit over conventional oxygen therapy.

How to cite this article

Maitra S, Bhattacharjee S, Som A. Noninvasive Ventilation and Oxygen Therapy after Extubation in Patients with Acute Respiratory Failure: A Meta-analysis of Randomized Controlled Trials. Indian J Crit Care Med 2019;23(9):414-422.

Resource use, characteristics and outcomes of prolonged non-invasive ventilation: a single-centre observational study in China

OBJECTIVE

To report the resource use, characteristics and outcomes of patients with prolonged non-invasive ventilation (NIV).

DESIGN

A single-centre observational study.

SETTING

An intensive care unit of a teaching hospital.

PARTICIPANTS

Patients who only received NIV because of acute respiratory failure were enrolled. Prolonged NIV was defined as subjects who received NIV ≥14 days. A total of 1539 subjects were enrolled in this study; 69 (4.5%) underwent prolonged NIV.

MAIN OUTCOME MEASURES

Predictors of prolonged NIV and hospital mortality.

RESULTS

The rate of do-not-intubate (DNI) orders was 9.1% (140/1539). At the beginning of NIV, a DNI order (OR 3.95, 95% CI 2.25 to 6.95) and pH ≥7.35 (2.20, 1.27 to 3.82) were independently associated with prolonged NIV. At days 1 and 7 of NIV, heart rate (1.01 (1.00 to 1.03) and 1.02 (1.00 to 1.03], respectively) and PaO₂/FiO₂<150 (2.19 (1.25 to 3.85) and 2.05 (1.04 to 4.04], respectively) were other independent risk factors for prolonged NIV. When patients who died after starting NIV but prior to 14 days were excluded, the association was strengthened. Regarding resource use, 77.1% of subjects received NIV<7 days and only accounted for 47.0% of NIV-days. However, 18.4% of subjects received NIV 7-13.9 days and accounted for 33.4% of NIV-days, 2.9% of subjects received NIV 14-20.9 days and accounted for 9.5% of NIV-days, and 1.6% of subjects received NIV≥21 days and accounted for 10.1% of NIV-days.

CONCLUSIONS

Our results indicate the resource use, characteristics and outcomes of a prolonged NIV population with a relatively high proportion of DNI orders. Subjects with prolonged NIV make up a high proportion of NIV-days and are at high risk for in-hospital mortality.

Basic Performance Tests of the MILL Intravascular CO2 Removal Catheter

Currently available treatment methods for acute lung failure show high rates of complications. There is an urgent need for alternative treatment methods. A catheter device which can be minimal invasively inserted into the vena cava for intracorporeal gas exchange was developed. Main components of the device are a drive unit and a membrane module. In this study, the flow behavior in a vena cava model with inserted catheter prototype was investigated in experiments and basic computational fluid dynamic (CFD) simulations. Main findings are that the miniature blood pump has suitable characteristics and generates sufficient power to overcome the pressure drop induced in the membrane module, and that the design of the membrane outlet might be critical to avoid additional pressure losses. Parts manufactured with a high resolution 3D printer have proven to be suitable for the prototyping process.

Survey on accessibility and real-life application of noninvasive ventilation

Noninvasive mechanical ventilation (NIV) is an accepted method of respiratory failure treatment; however, at present, little is known about the global factors limiting NIV application. A survey designed to determine NIV accessibility and limiting factors in world economies and regions was developed. The questionnaire was sent to members of the European Respiratory Society (ERS) Respiratory Intensive Care Assembly and all ERS National Delegates. Replies to the survey were collected from 161 respondents from 46 countries. NIV was found to be provided most frequently by pulmonologists and intensivists. In high-income economies (HIEs), NIV reimbursement in chronic respiratory failure treatment was found to be independent of the underlying disease and supplementary insurance (p<0.0001), whereas in upper-middle-income economies (UMIEs) it was found to be dependent on the underlying disease (p<0.0001). In chronic respiratory failure, NIV was not reimbursed in lower-middle-income economies (LMIEs) (p<0.0001). In LMIEs and UMIEs, the lack of financial resources was the main limiting factor in acute (p=0.007) and chronic respiratory failure (p<0.0001). In the income-level-based assessment, financing was recognised as relevant in LMIEs and UMIEs (p<0.0001), equipment in LMIEs and UMIEs (p=0.03), medical staff in all economies (p=0.02), and legal regulations in LMIEs (p=0.0005). It was confirmed that NIV in acute and chronic respiratory failure is reimbursed based on government regulations in UMIEs and HIEs (p<0.0001), and is not reimbursed and probably will not be reimbursed in the near future in LMIEs (p<0.0001). We conclude that financial constraints are still considered a major limiting factor for NIV use.

Approaches and techniques to avoid development or progression of acute respiratory distress syndrome

PURPOSE OF REVIEW

Despite major improvement in ventilation strategies, hospital mortality and morbidity of the acute respiratory distress syndrome (ARDS) remain high. A lot of therapies have been shown to be ineffective for established ARDS. There is a growing interest in strategies aiming at avoiding development and progression of ARDS.

RECENT FINDINGS

Recent advances in this field have explored identification of patients at high-risk, nonspecific measures to limit the risks of inflammation, infection and fluid overload, prevention strategies of ventilator-induced lung injury and patient self-inflicted lung injury, and pharmacological treatments.

SUMMARY

There is potential for improvement in the management of patients admitted to intensive care unit to reduce ARDS incidence. Apart from nonspecific measures, prevention of ventilator-induced lung injury and patient self-inflicted lung injury are of major importance.

Comparison of high flow nasal cannula oxygen and conventional oxygen therapy on ventilatory support duration during acute-on-chronic respiratory failure: study protocol of a multicentre, randomised, controlled trial. The 'HIGH-FLOW ACRF' study

INTRODUCTION

This study protocol describes a trial designed to investigate whether high-flow heated and humidified nasal oxygen (HFHO) therapy in patients with hypercapnic acute respiratory failure (ARF) reduces the need of non-invasive ventilation (NIV).

METHODS AND ANALYSIS

This is an open-label, superiority, international, parallel-group, multicentre randomised controlled two-arm trial, with an internal feasibility pilot phase. 242 patients with hypercapnic ARF requiring NIV admitted to an intensive care unit, an intermediate care or a respiratory care unit will be randomised in a 1:1 ratio to receive HFHO or standard oxygen in between NIV sessions. Randomisation will be centralised and stratified by centre and pH at admission (pH ≤7.25 or >7.25). The primary outcome will be the number of ventilator-free days (VFDs) and alive at day 28 postrandomisation. The secondary outcomes will encompass parameters related to the VFDs, comfort and tolerance variables, hospital length of stay and mortality. VFDs at 28 days postrandomisation will be compared between the two groups by Wilcoxon-Mann-Whitney two-sample rank-sum test in the intention-to-treat population. A sensitivity analysis will be conducted in the population of patients for whom the criteria of switching from NIV to spontaneous breathing, or conversely, are not strictly verified.

ETHICS AND DISSEMINATION

The protocol has been approved by the Comité de Protection des Personnes (CPP) Sud-Ouest & Outre-Mer IV (ref CPP17-049a/2017-A01830-53) and will be carried out in accordance with the Declaration of Helsinki and Good Clinical Practice guidelines. A trial steering committee will oversee the progress of the study. Findings will be disseminated through national and international scientific conferences, and publication in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT03406572.

Non-invasive ventilation in cardiogenic pulmonary edema

Cardiogenic pulmonary edema (CPE) is among the most common causes of acute respiratory failure (ARF) in the acute care setting and often requires ventilatory assistance. In patients with ARF due to CPE, use of non-invasive positive airway pressure can decrease the systemic venous return and the left ventricular (LV) afterload, thus reducing LV filling pressure and limiting pulmonary edema. In these patients, either non-invasive ventilation (NIV) or continuous positive airway pressure (CPAP) can improve vital signs and physiological parameters, decreasing the need for endotracheal intubation (ETI) and hospital mortality when compared to conventional oxygen therapy. Results on the use of NIV or CPAP in patients with CPE prior to hospitalization are not homogeneous among studies, hampering any conclusive recommendation regarding their role in the pre-hospital setting.

Non-invasive positive pressure ventilation in lung transplant recipients with acute respiratory failure: Beyond the perioperative period

PURPOSE

The purpose of this study is to evaluate outcomes in MICU lung transplant recipients with acute respiratory failure treated with non-invasive positive pressure ventilation (NPPV) and identify factors associated with NPPV failure (need for intubation).

METHODS

Retrospective chart review of all lung transplant recipients who were admitted with acute respiratory failure to the MICU from January 2009-August 2016 was completed. Logistic regression analysis was performed to determine which factors were independently associated with NPPV failure.

RESULTS

Of 156 patients included in the study, 125 (80.1%) were tried on NPPV. Sixty-eight (54.4%) were managed successfully with NPPV with a hospital survival rate of 94.1%. Subjects who failed NPPV had higher hospital mortality, similar to those intubated from the outset (15 [48.3%]; 22 [38.6%], p = .37). In multivariate analyses, APACHE III scores >78 (9.717 [3.346, 28.22]) and PaO2/FiO2 ≤ 151 (4.54 [1.72, 11.99]) were associated with greater likelihood of NPPV failure. There was no difference in NPPV failure based on the presence of BOS. In patients with high severity of illness, there was no difference in mortality between initial IMV and NPPV failure when stratified on the basis of hypoxemia (PaO2/FiO2 > 151, p-value 0.34; PaO2/FiO2 ≤ 151, p-value 0.99).

CONCLUSIONS

NPPV is a viable option for lung transplant recipients with acute respiratory failure. Extreme caution should be exercised when used in patients with high severity of illness (APACHE III >78) and/or severe hypoxemia (PaO2/FiO2 ≤ 151).

Noninvasive Options

Noninvasive ventilation (NIV) has assumed a central role in the treatment of selected patients with acute respiratory failure due to exacerbated chronic obstructive pulmonary disease or acute cardiogenic pulmonary edema. Recent advances in the understanding of physiologic aspects of NIV application through different interfaces and ventilator settings have led to improved patient-machine interaction, enhancing favorable NIV outcome. In recent years, the growing role of NIV in the acute care setting has led to the development of technical innovations to overcome the problems related to gas leakage and dead space, improving the quality of the devices and optimizing ventilation modes.

Initial nutritional management during noninvasive ventilation and outcomes: a retrospective cohort study

Background

Patients starting noninvasive ventilation (NIV) to treat acute respiratory failure are often unable to eat and therefore remain in the fasting state or receive nutritional support. Maintaining a good nutritional status has been reported to improve patient outcomes. In the present study, our primary objective was to describe the nutritional management of patients starting first-line NIV, and our secondary objectives were to assess potential associations between nutritional management and outcomes.

Methods

Observational retrospective cohort study of a prospective database fed by 20 French intensive care units. Adult medical patients receiving NIV for more than 2 consecutive days were included and divided into four groups on the basis of nutritional support received during the first 2 days of NIV: no nutrition, enteral nutrition, parenteral nutrition only, and oral nutrition only.

Results

Of the 16,594 patients admitted during the study period, 1075 met the inclusion criteria; of these, 622 (57.9%) received no nutrition, 28 (2.6%) received enteral nutrition, 74 (6.9%) received parenteral nutrition only, and 351 (32.7%) received oral nutrition only. After adjustment for confounders, enteral nutrition (vs. no nutrition) was associated with higher 28-day mortality (adjusted HR, 2.3; 95% CI, 1.2–4.4) and invasive mechanical ventilation needs (adjusted HR, 2.1; 95% CI, 1.1–4.2), as well as with fewer ventilator-free days by day 28 (adjusted relative risk, 0.7; 95% CI, 0.5–0.9).

Conclusions

Nearly three-fifths of patients receiving NIV fasted for the first 2 days. Lack of feeding or underfeeding was not associated with mortality. The optimal route of nutrition for these patients needs to be investigated.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-017-1867-y) contains supplementary material, which is available to authorized users.

Evidence-based Utilization of Noninvasive Ventilation and Patient Outcomes

RATIONALE

Strong evidence supports use of noninvasive ventilation (NIV) for patients with respiratory distress from chronic obstructive pulmonary disease and heart failure (strong evidence conditions [SECs]). Despite unclear benefits of NIV for other causes of acute respiratory failure, utilization for conditions with weaker evidence is increasing, despite evidence demonstrating higher mortality for patients who suffer NIV failure (progression from NIV to invasive mechanical ventilation [IMV])) compared with being treated initially with IMV.

OBJECTIVES

To determine the association of hospital variation in evidence-based utilization of NIV with patient outcomes.

METHODS

Using the California State Inpatient Database 2011, we identified adult patients who received NIV. Patients were considered to have an SEC for NIV if they had an acute exacerbation of chronic obstructive pulmonary disease or heart failure. We used multivariable hierarchical logistic regression to determine the association between hospital rates of NIV use for SECs and patient risk of NIV failure (need for IMV after NIV).

RESULTS

Among 22,706 hospitalizations with NIV as the initial ventilatory strategy, 6,820 (30.0%) had SECs. Patients with SECs had lower risk of NIV failure than patients with weak evidence conditions (8.1 vs. 18.2%, P < 0.0001). Regardless of underlying diagnosis, patients admitted to hospitals with greater use of NIV for SECs had lower risk of NIV failure (Quartile 4 vs. Quartile 1 adjusted odds ratio = 0.62; 95% CI = 0.49-0.80). Even patients without an SEC benefited from admission to hospitals that used NIV more often for patients with SECs (Quartile 4 vs. Quartile 1 adjusted odds ratio for NIV failure = 0.68; 95% CI = 0.52-0.88).

CONCLUSIONS

Most patients who received NIV did not have conditions with strong supporting evidence for its use with wide institutional variation in patient selection for NIV. Surprisingly, we found that all patients, even those without an SEC, benefited from admission to hospitals with greater evidence-based utilization of NIV, suggesting a "hospital effect" that is synergistic with patient selection.

Noninvasive Ventilation in Acute Hypoxemic Nonhypercapnic Respiratory Failure: A Systematic Review and Meta-Analysis

Supplemental Digital Content is available in the text.

Objective:

To evaluate the effectiveness of noninvasive ventilation in patients with acute hypoxemic nonhypercapnic respiratory failure unrelated to exacerbation of chronic obstructive pulmonary disease and cardiogenic pulmonary edema.

Data Sources:

PubMed, EMBASE, Cochrane library, Web of Science, and bibliographies of articles were retrieved inception until June 2016.

Study Selection:

Randomized controlled trials comparing application of noninvasive ventilation with standard oxygen therapy in adults with acute hypoxemic nonhypercapnic respiratory failure were included. Chronic obstructive pulmonary disease exacerbation and cardiogenic pulmonary edema patients were excluded. The primary outcome was intubation rate; ICU mortality and hospital mortality were secondary outcomes.

Data Extraction:

Demographic variables, noninvasive ventilation application, and outcomes were retrieved. Internal validity was assessed using the risk of bias tool. The strength of evidence was assessed using Grading of Recommendations Assessment, Development, and Evaluation methodology.

Data Synthesis:

Eleven studies (1,480 patients) met the inclusion criteria and were analyzed by using a random effects model. Compared with standard oxygen therapy, the pooled effect showed that noninvasive ventilation significantly reduced intubation rate with a summary risk ratio of 0.59 (95% CI, 0.44–0.79; p = 0.0004). Furthermore, hospital mortality was also significantly reduced (risk ratio, 0.46; 95% CI, 0.24–0.87; p = 0.02). Subgroup meta-analysis showed that the application of bilevel positive support ventilation (bilevel positive airway pressure) was associated with a reduction in ICU mortality (p = 0.007). Helmet noninvasive ventilation could reduce hospital mortality (p = 0.0004), whereas face/nasal mask noninvasive ventilation could not.

Conclusions:

Noninvasive ventilation decreased endotracheal intubation rates and hospital mortality in acute hypoxemia nonhypercapnic respiratory failure excluding chronic obstructive pulmonary disease exacerbation and cardiogenic pulmonary edema patients. There is no sufficient scientific evidence to recommend bilevel positive airway pressure or helmet due to the limited number of trials available. Large rigorous randomized trials are needed to answer these questions definitely.

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.

Efficacy of non-invasive ventilation and oxygen therapy on immunocompromised patients with acute hypoxaemic respiratory failure: protocol for a systematic review and meta-analysis of randomised controlled trials

BACKGROUND

The number of immunocompromised patients has increased in recent years. Acute respiratory failure is a common complication leading to intensive care unit (ICU) admission and high mortality among such patients. The use of non-invasive ventilation (NIV) or oxygen therapy among these patients remains controversial, according to the inconsistent results of several randomised clinical trials (RCTs). This meta-analysis aims to evaluate whether NIV or oxygen therapy is the more appropriate initial oxygenation strategy for the immunocompromised patients with acute respiratory failure.

METHOD

We will search all the RCTs that compared the efficacy of NIV and oxygen therapy on immunocompromised adult patients with acute hypoxaemic respiratory failure on the major databases (Cochrane Library, MEDLINE, EMBASE, Web of Science and others), conference proceedings and grey literature. Eligible RCTs will be included in accordance with the pre-specified eligibility criteria. The risk of bias will be assessed using the Cochrane Collaboration criteria and the quality of evidence will be assessed with the Grading of Recommendations Assessment, Development and Evaluation system. Data will be extracted with a standardised form and analysed using RevMan V.5.3 analyses software. Heterogeneity will be assessed using I² statistic and the source of which will be investigated. Publication bias will be identified with the funnel plot.

ETHICS AND DISSEMINATION

Ethical approval is not required since it is not carried out in humans. The systematic review will be published in peer-reviewed journals and disseminated extensively through conferences.

Epidemiology of NIV for Acute Respiratory Failure in COPD Patients: Results from the International Surveys vs. the "Real World"

Non-invasive ventilation (NIV) has been recommended as the  first-line ventilation modality for acute respiratory failure (ARF) due to acute exacerbation of chronic obstructive pulmonary disease (AECOPD) based on strong evidence. However, everyday clinical practice may differ from findings of multiple randomized controlled trials. Physicians and respiratory therapists involved in NIV management have been queried about its utilization and effectiveness. In addition to these estimates, cohort studies and analysis of large inpatient dataset of patients with AECOPD and ARF managed with NIV have been extensively published over the last two decades. This review summarizes the perception of medical staff vs. the "real life" data about NIV use for ARF in AECOPD patients.

Noninvasive ventilation with helium-oxygen mixture in hypercapnic COPD exacerbation: aggregate meta-analysis of randomized controlled trials

When used as a driving gas during NIV in hypercapnic COPD exacerbation, a helium–oxygen (He/O₂) mixture reduces the work of breathing and gas trapping. The potential for He/O₂ to reduce the rate of NIV failure leading to intubation and invasive mechanical ventilation has been evaluated in several RCTs. The goal of this meta-analysis is to assess the effect of NIV driven by He/O₂ compared to air/O₂ on patient-centered outcomes in hypercapnic COPD exacerbation. Relevant RCTs were searched using standard procedures. The main endpoint was the rate of NIV failure. The effect size was computed by a fixed-effect model, and estimated as odds ratio (OR) with 95% confidence interval (CI). Additional endpoints were ICU mortality, NIV-related side effects, and the length and costs of ICU stay. Three RCTs fulfilled the selection criteria and enrolled a total of 772 patients (386 patients received He/O₂ and 386 received air/O₂). Pooled analysis showed no difference in the rate of NIV failure when using He/O₂ mixture compared to air/O₂: 17 vs 19.7%, respectively; OR 0.84, 95% CI 0.58–1.22; p = 0.36; I² for heterogeneity = 0%, and no publication bias. ICU mortality was also not different: OR 0.8, 95% CI 0.45–1.4; p = 0.43; I² = 5%. However, He/O₂ was associated with less NIV-related adverse events (OR 0.56, 95% CI 0.4–0.8, p = 0.001), and a shorter length of ICU stay (difference in means = −1.07 day, 95% CI −2.14 to −0.004, p = 0.049). Total hospital costs entailed by hospital stay and NIV gas were not different: difference in means = −279$, 95% CI −2052–1493, p = 0.76. Compared to air/O₂, He/O₂ does not reduce the rate of NIV failure in hypercapnic COPD exacerbation. It is, however, associated with a lower incidence of NIV-related adverse events and a shortening of ICU length of stay with no increase in hospital costs.

Randomized crossover trial of a pressure sensing visual feedback system to improve mask fitting in noninvasive ventilation

BACKGROUND AND OBJECTIVE

A good mask fit, avoiding air leaks and pressure effects on the skin are key elements for a successful noninvasive ventilation (NIV). However, delivering practical training for NIV is challenging, and it takes time to build experience and competency. This study investigated whether a pressure sensing system with real-time visual feedback improved mask fitting.

METHODS

During an NIV training session, 30 healthcare professionals (14 trained in mask fitting and 16 untrained) performed two mask fittings on the same healthy volunteer in a randomized order: one using standard mask-fitting procedures and one with additional visual feedback on mask pressure on the nasal bridge. Participants were required to achieve a mask fit with low mask pressure and minimal air leak (<10 L/min). Pressure exerted on the nasal bridge, perceived comfort of mask fit and staff- confidence were measured.

RESULTS

Compared with standard mask fitting, a lower pressure was exerted on the nasal bridge using the feedback system (71.1 ± 17.6 mm Hg vs 63.2 ± 14.6 mm Hg, P < 0.001). Both untrained and trained healthcare professionals were able to reduce the pressure on the nasal bridge (74.5 ± 21.2 mm Hg vs 66.1 ± 17.4 mm Hg, P = 0.023 and 67 ± 12.1 mm Hg vs 60 ± 10.6 mm Hg, P = 0.002, respectively) using the feedback system and self-rated confidence increased in the untrained group.

CONCLUSION

Real-time visual feedback using pressure sensing technology supported healthcare professionals during mask-fitting training, resulted in a lower pressure on the skin and better mask fit for the volunteer, with increased staff confidence.

Association Between Noninvasive Ventilation and Mortality Among Older Patients With Pneumonia

OBJECTIVE

Despite increasing use, evidence is mixed as to the appropriate use of noninvasive ventilation in patients with pneumonia. We aimed to determine the relationship between receipt of noninvasive ventilation and outcomes for patients with pneumonia in a real-world setting.

DESIGN, SETTING, PATIENTS

We performed a retrospective cohort study of Medicare beneficiaries (aged > 64 yr) admitted to 2,757 acute-care hospitals in the United States with pneumonia, who received mechanical ventilation from 2010 to 2011.

EXPOSURES

Noninvasive ventilation versus invasive mechanical ventilation.

MEASUREMENT AND MAIN RESULTS

The primary outcome was 30-day mortality with Medicare reimbursement as a secondary outcome. To account for unmeasured confounding associated with noninvasive ventilation use, an instrumental variable was used-the differential distance to a high noninvasive ventilation use hospital. All models were adjusted for patient and hospital characteristics to account for measured differences between groups. Among 65,747 Medicare beneficiaries with pneumonia who required mechanical ventilation, 12,480 (19%) received noninvasive ventilation. Patients receiving noninvasive ventilation were more likely to be older, male, white, rural-dwelling, have fewer comorbidities, and were less likely to be acutely ill as measured by organ failures. Results of the instrumental variable analysis suggested that, among marginal patients, receipt of noninvasive ventilation was not significantly associated with differences in 30-day mortality when compared with invasive mechanical ventilation (54% vs 55%; p = 0.92; 95% CI of absolute difference, -13.8 to 12.4) but was associated with significantly lower Medicare spending ($18,433 vs $27,051; p = 0.02).

CONCLUSIONS

Among Medicare beneficiaries hospitalized with pneumonia who received mechanical ventilation, noninvasive ventilation use was not associated with a real-world mortality benefit. Given the wide CIs, however, substantial harm associated with noninvasive ventilation could not be excluded. The use of noninvasive ventilation for patients with pneumonia should be cautioned, but targeted enrollment of marginal patients with pneumonia could enrich future randomized trials.

IL-8 predicts early mortality in patients with acute hypercapnic respiratory failure treated with noninvasive positive pressure ventilation

Background

Patients with Acute Hypercapnic Respiratory Failure (AHRF) who are unresponsive to appropriate medical treatment, are often treated with Noninvasive Positive Pressure Ventilation (NPPV). Clinical predictors of the outcome of this treatment are scarce. Therefore, we evaluated the role of the biomarkers IL-8 and GDF-15 in predicting 28-day mortality in patients with AHRF who receive treatment with NPPV.

Methods

The study population were 46 patients treated with NPPV for AHRF. Clinical and background data was registered and blood samples taken for analysis of inflammatory biomarkers. IL-8 and GDF-15 were selected for analysis, and related to risk of 28-day mortality (primary endpoint) using Cox proportional hazard models adjusted for gender, age and various clinical parameters.

Results

Of the 46 patients, there were 3 subgroup in regards to primary diagnosis: Acute Exacerbation of COPD (AECOPD, n = 34), Acute Heart Failure (AHF, n = 8) and Acute Exacerbation in Obesity Hypoventilation Syndrome (AEOHS, n = 4). There was significant difference in the basic characteristic of the subgroups, but not in the clinical parameters that were used in treatment decisions. 13 patients died within 28 days of admission (28%). The Hazard Ratio for 28-days mortality per 1-SD increment of IL-8 was 3.88 (95% CI 1.86–8.06, p < 0.001). When IL-8 values were divided into tertiles, the highest tertile had a significant association with 28 days mortality, HR 10.02 (95% CI 1.24–80.77, p for trend 0.03), compared with the lowest tertile. This correlation was maintained when the largest subgroup with AECOPD was analyzed. GDF-15 was correlated in the same way, but when put into the same model as IL-8, the significance disappeared.

Conclusion

IL-8 is a target to explore further as a predictor of 28 days mortality, in patients with AHRF treated with NPPV.

Noninvasive ventilation for acute exacerbations of asthma: A systematic review of the literature

BACKGROUND

Asthma is a chronic disease characterised by reversible airway obstruction caused by bronchospasm, mucous and oedema. People with asthma commonly experience acute exacerbations of their disease requiring hospitalisation and subsequent utilisation of economic and healthcare resources. Noninvasive ventilation has been suggested as a treatment for acute exacerbations of asthma due to its ability to provide airway stenting, optimal oxygen delivery and decreased work of breathing.

OBJECTIVES

This paper is a systematic review of the available published research focused on the use of noninvasive ventilation for the treatment of acute exacerbations of asthma to determine if this treatment provides better outcomes for patients compared to standard medical therapy.

METHOD

Database searches were conducted using EBSCOhost, MEDLINE and PubMed. Search terms used were combinations of 'noninvasive ventilation', 'BiPAP', 'CPAP', 'wheez*' and 'asthma'. Articles were included if they were research papers focused on adult patients with asthma and a treatment of noninvasive ventilation, and were published in full text in English. Included articles were reviewed using the National Health and Medical Research Council (Australia) evidence hierarchy and quality appraisal tools.

RESULTS

There were 492 articles identified from the database searches. After application of inclusion/exclusion criteria 13 articles were included in the systematic review. Studies varied significantly in design, endpoints and outcomes. There was a trend in better outcomes for patients with acute asthma who were treated with noninvasive ventilation compared to standard medical therapy, however, the variability of the studies meant that no conclusive recommendations could be made.

CONCLUSION

More research is required before noninvasive ventilation can be conclusively recommended for the treatment of acute exacerbations of asthma.

Risk factors for noninvasive ventilation failure in patients with acute cardiogenic pulmonary edema: A prospective, observational cohort study

PURPOSE

We identified risk factors for noninvasive ventilation (NIV) failure in patients with acute cardiogenic pulmonary edema (ACPE).

MATERIALS AND METHODS

We conducted an observational cohort study over a 3-year period in a 28-bed emergency intensive care unit (EICU) and prospectively included all consecutive patients in whom NIV was attempted as initial ventilatory support for ACPE. The primary outcome variables were NIV failure rate and risk factors for NIV failure.

RESULTS

Among the 118 patients in the study, NIV failed for 44 (37.3%) patients. Risk factors for NIV failure were Killip class IV (odds ratio [OR], 28.56; 95% confidence interval [CI], 2.17-375.73; p=0.011), left ventricular ejection fraction (LVEF) <30% (OR, 9.54; 95% CI, 1.01-90.55; p=0.050) and B-type natriuretic peptide (BNP) ≥3350pg/mL (OR, 39.63; 95% CI, 3.92-400.79; p=0.002) at baseline, and fluid balance ≥400mL within 24h after ACPE (OR, 13.19; 95% CI, 1.18-147.70; p=0.036).

CONCLUSIONS

NIV failure occurred in 37.3% of ACPE patients in a real-world EICU. When patients had Killip class IV, a lower LVEF, a higher BNP, and a more positive fluid balance within 24h after ACPE, the risk of failure was higher. TRIAL REGISTRATION CLINICALTRIALS.

GOV IDENTIFIER

NCT02653365.