Noninvasive ventilation with helmet versus control strategy in patients with acute respiratory failure: a systematic review and meta-analysis of controlled studies

Swallowing during provision of helmet ventilation: Review and provisional multidisciplinary guidance

Use of noninvasive ventilation provided by a helmet increased globally during and after the COVID-19 pandemic. This approach may reduce need for intubation and its associated clinical complications in critically ill patients. Use of helmet interface minimizes virus aerosolization while enabling verbal communication, oral feeding and coughing/expectoration of secretions during its administration. Although improved oral hydration is a recognized benefit of helmet NIV, relatively little is known about the safety and efficiency of swallowing during helmet NIV. Risk of aspiration is a key consideration given the fragile pulmonary status of critically ill patients requiring respiratory support, and therefore the decision to initiate oral intake is best made based on multidisciplinary input. We reviewed the current published evidence on NIV and its effects on upper airway physiology and swallowing function. We then presented a case example demonstrating preservation of swallowing performance with helmet NIV. Last, we offer provisional multidisciplinary guidance for clinical practice, and provide directions for future research.

Safety and efficacy of noninvasive ventilation for acute respiratory failure in general medical ward: a prospective cohort study

Background

Noninvasive ventilation (NIV) is recommended for use in patients with acute respiratory failure of various etiologies. However, we do not know whether the use of NIV in general medical wards is safe and effective. This study aimed to evaluate the safety and efficacy of using NIV and factors associated with NIV failure in general medical wards.

Methods

A prospective cohort study was conducted in general medical wards of the University Hospital. Adult patients with acute respiratory failure treated with NIV were enrolled. The subjects were managed by a multidisciplinary care team that was well trained in the NIV device. The primary outcome was the rate of NIV failure at 48 hours. Secondary outcomes included hospital mortality and factors associated with NIV failure.

Results

A total of 86 patients were enrolled. The mean age was 70±17 years old. The Acute Physiology and Chronic Health Evaluation (APACHE) III and the Sequential Organ Failure Assessment (SOFA) scores were 56±17 and 4±3, respectively. The most common indication of NIV use was cardiogenic pulmonary edema (34.9%). The rate of NIV failure at 48 hours and hospital mortality were 20.9% and 12.8%, respectively. The SOFA score was associated with failure of NIV at 48 hours [odds ratio (OR) 1.48, 95% confidence interval (CI): 1.16-1.89; P=0.002].

Conclusions

NIV was safe and effective on general medical wards. Cardiogenic pulmonary edema was the most common indication for the application of NIV. The SOFA score was associated with the failure of NIV at 48 hours.

Long-term outcome of COVID-19 patients treated with helmet noninvasive ventilation vs. high-flow nasal oxygen: a randomized trial

BACKGROUND

Long-term outcomes of patients treated with helmet noninvasive ventilation (NIV) are unknown: safety concerns regarding the risk of patient self-inflicted lung injury and delayed intubation exist when NIV is applied in hypoxemic patients. We assessed the 6-month outcome of patients who received helmet NIV or high-flow nasal oxygen for COVID-19 hypoxemic respiratory failure.

METHODS

In this prespecified analysis of a randomized trial of helmet NIV versus high-flow nasal oxygen (HENIVOT), clinical status, physical performance (6-min-walking-test and 30-s chair stand test), respiratory function and quality of life (EuroQoL five dimensions five levels questionnaire, EuroQoL VAS, SF36 and Post-Traumatic Stress Disorder Checklist for the DSM) were evaluated 6 months after the enrollment.

RESULTS

Among 80 patients who were alive, 71 (89%) completed the follow-up: 35 had received helmet NIV, 36 high-flow oxygen. There was no inter-group difference in any item concerning vital signs (N = 4), physical performance (N = 18), respiratory function (N = 27), quality of life (N = 21) and laboratory tests (N = 15). Arthralgia was significantly lower in the helmet group (16% vs. 55%, p = 0.002). Fifty-two percent of patients in helmet group vs. 63% of patients in high-flow group had diffusing capacity of the lungs for carbon monoxide < 80% of predicted (p = 0.44); 13% vs. 22% had forced vital capacity < 80% of predicted (p = 0.51). Both groups reported similar degree of pain (p = 0.81) and anxiety (p = 0.81) at the EQ-5D-5L test; the EQ-VAS score was similar in the two groups (p = 0.27). Compared to patients who successfully avoided invasive mechanical ventilation (54/71, 76%), intubated patients (17/71, 24%) had significantly worse pulmonary function (median diffusing capacity of the lungs for carbon monoxide 66% [Interquartile range: 47-77] of predicted vs. 80% [71-88], p = 0.005) and decreased quality of life (EQ-VAS: 70 [53-70] vs. 80 [70-83], p = 0.01).

CONCLUSIONS

In patients with COVID-19 hypoxemic respiratory failure, treatment with helmet NIV or high-flow oxygen yielded similar quality of life and functional outcome at 6 months. The need for invasive mechanical ventilation was associated with worse outcomes. These data indicate that helmet NIV, as applied in the HENIVOT trial, can be safely used in hypoxemic patients. Trial registration Registered on clinicaltrials.gov NCT04502576 on August 6, 2020.

Advantages and drawbacks of helmet noninvasive support in acute respiratory failure

INTRODUCTION

Non-invasive ventilation (NIV) represents an effective strategy for managing acute respiratory failure. Facemask NIV is strongly recommended in acute exacerbation of chronic obstructive pulmonary disease (AECOPD) with hypercapnia and acute cardiogenic pulmonary edema (ACPE). Its role in managing acute hypoxemic respiratory failure (AHRF) remains a debated issue. NIV and continuous positive airway pressure (CPAP) delivered through the helmet are recently receiving growing interest for AHRF management.

AREAS COVERED

In this narrative review, we discuss the clinical applications of helmet support compared to the other available noninvasive strategies in the different phenotypes of acute respiratory failure.

EXPERT OPINION

Helmets enable the use of high positive end-expiratory pressure, which may protect from self-inflicted lung injury: in AHRF, the possible superiority of helmet support over other noninvasive strategies in terms of clinical outcome has been hypothesized in a network metanalysis and a randomized trial, but has not been confirmed by other investigations and warrants confirmation. In AECOPD patients, helmet efficacy may be inferior to that of face masks, and its use prompts caution due to the risk of CO₂ rebreathing. Helmet support can be safely applied in hypoxemic patients with ACPE, with no advantages over facemasks.

Helmet noninvasive support for acute hypoxemic respiratory failure: rationale, mechanism of action and bedside application

Introduction

Helmet noninvasive support may provide advantages over other noninvasive oxygenation strategies in the management of acute hypoxemic respiratory failure. In this narrative review based on a systematic search of the literature, we summarize the rationale, mechanism of action and technicalities for helmet support in hypoxemic patients.

Main results

In hypoxemic patients, helmet can facilitate noninvasive application of continuous positive-airway pressure or pressure-support ventilation via a hood interface that seals at the neck and is secured by straps under the arms. Helmet use requires specific settings. Continuous positive-airway pressure is delivered through a high-flow generator or a Venturi system connected to the inspiratory port of the interface, and a positive end-expiratory pressure valve place at the expiratory port of the helmet;  alternatively, pressure-support ventilation is delivered by connecting the helmet to a mechanical ventilator through a bi-tube circuit. The helmet interface allows continuous treatments with high positive end-expiratory pressure with good patient comfort. Preliminary data suggest that helmet noninvasive ventilation (NIV) may provide physiological benefits compared to other noninvasive oxygenation strategies (conventional oxygen, facemask NIV, high-flow nasal oxygen) in non-hypercapnic patients with moderate-to-severe hypoxemia (PaO₂/FiO₂ ≤ 200 mmHg), possibly because higher positive end-expiratory pressure (10–15 cmH₂O) can be applied for prolonged periods with good tolerability. This improves oxygenation, limits ventilator inhomogeneities, and may attenuate the potential harm of lung and diaphragm injury caused by vigorous inspiratory effort. The potential superiority of helmet support for reducing the risk of intubation has been hypothesized in small, pilot randomized trials and in a network metanalysis.

Conclusions

Helmet noninvasive support represents a promising tool for the initial management of patients with severe hypoxemic respiratory failure. Currently, the lack of confidence with this and technique and the absence of conclusive data regarding its efficacy render helmet use limited to specific settings, with expert and trained personnel. As per other noninvasive oxygenation strategies, careful clinical and physiological monitoring during the treatment is essential to early identify treatment failure and avoid delays in intubation.

The right interface for the right patient in noninvasive ventilation: a systematic review

INTRODUCTION

Research in the field of noninvasive ventilation (NIV) has contributed to the development of new NIV interfaces. However, interface tolerance plays a crucial role in determining the beneficial effects of NIV therapy.

AREAS COVERED

This systematic review explores the most significant scientific research on NIV interfaces, with a focus on the potential impact that their design might have on treatment adherence and clinical outcomes. The rationale on the choice of the right interface among the wide variety of devices that are currently available is discussed here.

EXPERT OPINION

The paradigm "The right mask for the right patient" seems to be difficult to achieve in real life. Ranging from acute to chronic settings, the gold standard should include the tailoring of NIV interfaces to patients' needs and preferences. However, such customization may be hampered by issues of economic nature. High production costs and the increasing demand represent consistent burdens and have to be considered when dealing with patient-tailored NIV interfaces. New research focusing on developing advanced and tailored NIV masks should be prioritized; indeed, interfaces should be designed according to the specific patient and clinical setting where they need to be used.

Helmet-Noninvasive Ventilation for Hospitalized Critically Ill COVID-19 Patients: Has Vaccination and the New Variants Changed Evidence?

Noninvasive ventilation (NIV) is a technique for breathing support that significantly improves gas exchange and vital signs, reducing intubation and mortality rates. Helmets, unlike facemasks, allow for longer-term treatment and better ventilation, also being more cost-effective. As of today, we have found no reviews addressing this topic. This review aims to identify, map, and describe the characteristics of the use of noninvasive ventilation through helmet interface in critically ill COVID-19 adult patients hospitalized in acute care settings throughout the multiple moments that defined the COVID-19 pandemic. This scoping review will follow the methodology for scoping reviews proposed by JBI. A set of relevant electronic databases will be searched using terms such as COVID-19, helmet, and noninvasive ventilation. Two reviewers will independently perform the study selection regarding their eligibility. Data extraction will be accomplished using a researcher’s developed tool considering the review questions. Findings will be presented in tables and a narrative description that aligns with the review’s objective. This scoping review will consider any quantitative, qualitative, mixed-methods studies and systematic review designs for inclusion, focusing on the use of helmet on critically ill adult patients with COVID-19 hospitalized in acute care settings.

Non-Invasive Ventilation in the Prehospital Emergency Setting: A Systematic Review and Meta-Analysis

INTRODUCTION

Noninvasive ventilation is a well-established treatment for acute respiratory failure, being increasingly applied in the prehospital setting. This systematic review and meta-analysis aims to investigate whether early prehospital initiation of noninvasive ventilation reduces mortality compared to standard oxygen therapy.

METHODS

We searched PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials from inception to February 7^th, 2022, for studies comparing prehospital noninvasive ventilation performed by emergency medical services versus standard oxygen therapy in patients with acute respiratory failure. The primary outcome was mortality at the longest follow-up available.

RESULTS

We included ten randomized studies and two quasi-randomized studies for a total of 1485 patients. Prehospital treatment with noninvasive ventilation compared with standard oxygen therapy did not significantly reduce mortality at the longest follow-up available (107/810 [13%] vs 114/772 [15%]; RR = 0.89; 95% CI, 0.70-1.13; P = 0.34; I²=24%). The endotracheal intubation rate was reduced when receiving prehospital noninvasive ventilation (38/776 [4.9%] vs 81/743 [11%]; RR = 0.44; 95% CI, 0.31-0.63; P < 0.001; I²=0%; number needed to treat 17). The intensive care admission rate (114/532 [21%] vs 129/507 [25%]; RR = 0.85; 95% CI, 0.69-1.04; P = 0.11; I²=0%) and length of hospital stay (mean difference=-1.29 days; 95% CI, -3.35-0.77; P = 0.21; I²=82%) were similar between groups.

CONCLUSIONS

Adults with acute respiratory failure treated in the prehospital setting with noninvasive ventilation had a lower risk of intubation than those managed with standard oxygen therapy, with similar risk of death, intensive care admission, and length of hospital stay.

REVIEW REGISTRATION

PROSPERO CRD42021284947.

Various Aspects of Non-Invasive Ventilation in COVID-19 Patients: A Narrative Review

Non-invasive ventilation (NIV) is primarily used to treat acute respiratory failure. However, it has broad applications to manage a range of other diseases successfully. The main advantage of NIV lies in its capability to provide the same physiological effects as invasive ventilation while avoiding the placement of an artificial airway and its associated life-threatening complications. The war on the COVID-19 pandemic is far from over. The present narrative review aimed at identifying various aspects of NIV usage, in COVID-19 and other patients, such as the onset time, mode, setting, positioning, sedation, and types of interface. A search for articles published from May 2020 to April 2021 was conducted using MEDLINE, PMC central, Scopus, Web of Science, Cochrane Library, and Embase databases. Of the initially identified 5,450 articles, 73 studies and 24 guidelines on the use of NIV were included. The search was limited to studies involving human cases and English language articles. Despite several reported benefits of NIV, the evidence on the use of NIV in COVID-19 patients does not yet fully support its routine use.

Role of helmet ventilation during the 2019 coronavirus disease pandemic

Coronavirus disease 2019 (COVID-19) has been declared a pandemic by the World Health Organization; it has affected millions of people and caused hundreds of thousands of deaths. Patients with COVID-19 pneumonia may develop acute hypoxia respiratory failure and require noninvasive respiratory support or invasive respiratory management. Healthcare workers have a high risk of contracting COVID-19 while fitting respiratory devices. Recently, European experts have suggested that the use of helmet continuous positive airway pressure should be the first choice for acute hypoxia respiratory failure caused by COVID-19 because it reduces the spread of the virus in the ambient air. By contrast, in the United States, helmets were restricted for respiratory care before the COVID-19 pandemic until the Food and Drug Administration provided the ‘Umbrella Emergency Use Authorization for Ventilators and Ventilator Accessories’. This narrative review provides an evidence-based overview of the use of helmet ventilation for patients with respiratory failure.

Comparison of Effect of Non-invasive Ventilation Delivered by Helmet vs Face Mask in Patients with COVID-19 Infection: A Randomized Control Study

Background and aims

We compared the effectiveness of non-invasive ventilation (NIV) provided by helmet mask vs face mask in patients with COVID-19.

Methods and materials

Between March and May 2021, a single-center, prospective, open-label randomized controlled research was undertaken. Sixty patients were randomly assigned to one of two groups based on the NIV delivery interface. In group I (n = 30) helmet mask was used and in group II (n = 30) face mask was used for delivery of NIV. The proportion of patients in each group who required endotracheal intubation was the primary outcome. The duration of NIV, length of stay in the intensive care unit (ICU), hospital mortality, ratio of partial pressure of oxygen to fraction of inspired oxygen (PaO₂/FiO₂), respiratory rate, patient comfort, and complications were all documented as secondary outcomes.

Results

In both groups, demographics, clinical characteristics, and treatment received were comparable. Around 10% of patients in the helmet mask group were intubated, while 43.3% of patients in the face mask group were intubated (p = 0.004). The two groups demonstrated similar hemodynamic patterns. The use of a helmet mask, on the other hand, resulted in enhanced oxygenation (263.57 ± 31.562 vs 209.33 ± 20.531, p = 0.00), higher patient satisfaction (p = 0.001), a lower risk of complications, and a shorter NIV and ICU stay (p = 0.001) (4.53 ± 0.776 vs 7.60 ± 1.354, p = 0.00 and 6.37 ± 0.556 vs 11.57 ± 2.161, p = 0.00).

Conclusion

Helmet mask could be a reliable interface for delivery of NIV in COVID-19 and results in a lower rate of endotracheal intubation, better oxygenation with greater patient comfort and shorter ICU stay as compared to face mask used for NIV.

How to cite this article

Saxena A, Nazir N, Pandey R, Gupta S. Comparison of Effect of Non-invasive Ventilation Delivered by Helmet vs Face Mask in Patients with COVID-19 Infection: A Randomized Control Study. Indian J Crit Care Med 2022;26(3):282-287.

Helmet noninvasive ventilation for COVID-19 patients (Helmet-COVID): statistical analysis plan for a randomized controlled trial

BACKGROUND

Noninvasive respiratory support is frequently needed for patients with acute hypoxemic respiratory failure due to coronavirus disease 19 (COVID-19). Helmet noninvasive ventilation has multiple advantages over other oxygen support modalities but data about effectiveness are limited.

METHODS

In this multicenter randomized trial of helmet noninvasive ventilation for COVID-19 patients, 320 adult ICU patients (aged ≥14 years or as per local standards) with suspected or confirmed COVID-19 and acute hypoxemic respiratory failure (ratio of arterial oxygen partial pressure to fraction of inspired oxygen < 200 despite supplemental oxygen with a partial/non-rebreathing mask at a flow rate of 10 L/min or higher) will be randomized to helmet noninvasive ventilation with usual care or usual care alone, which may include mask noninvasive ventilation, high-flow nasal oxygen, or standard oxygen therapy. The primary outcome is death from any cause within 28 days after randomization. The trial has 80% power to detect a 15% absolute risk reduction in 28-day mortality from 40 to 25%. The primary outcome will be compared between the helmet and usual care group in the intention-to-treat using the chi-square test. Results will be reported as relative risk  and 95% confidence interval. The first patient was enrolled on February 8, 2021. As of August 1, 2021, 252 patients have been enrolled from 7 centers in Saudi Arabia and Kuwait.

DISCUSSION

We developed a detailed statistical analysis plan to guide the analysis of the Helmet-COVID trial, which is expected to conclude enrollment in November 2021.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04477668 . Registered on July 20, 2020.

Gas conditioning during helmet noninvasive ventilation: effect on comfort, gas exchange, inspiratory effort, transpulmonary pressure and patient-ventilator interaction

Background

There is growing interest towards the use of helmet noninvasive ventilation (NIV) for the management of acute hypoxemic respiratory failure. Gas conditioning through heat and moisture exchangers (HME) or heated humidifiers (HHs) is needed during facemask NIV to provide a minimum level of humidity in the inspired gas (15 mg H₂O/L). The optimal gas conditioning strategy during helmet NIV remains to be established.

Methods

Twenty patients with acute hypoxemic respiratory failure (PaO₂/FiO₂ < 300 mmHg) underwent consecutive 1-h periods of helmet NIV (PEEP 12 cmH₂O, pressure support 12 cmH₂O) with four humidification settings, applied in a random order: double-tube circuit with HHs and temperature set at 34 °C (HH34) and 37 °C (HH37); Y-piece circuit with HME; double-tube circuit with no humidification (NoH). Temperature and humidity of inhaled gas were measured through a capacitive hygrometer. Arterial blood gases, discomfort and dyspnea through visual analog scales (VAS), esophageal pressure swings (ΔP_ES) and simplified pressure–time product (PTP_ES), dynamic transpulmonary driving pressure (ΔP_L) and asynchrony index were measured in each step.

Results

Median [IqR] absolute humidity, temperature and VAS discomfort were significantly lower during NoH vs. HME, HH34 and HH37: absolute humidity (mgH₂O/L) 16 [12–19] vs. 28 [23–31] vs. 28 [24–31] vs. 33 [29–38], p < 0.001; temperature (°C) 29 [28–30] vs. 30 [29–31] vs. 31 [29–32] vs 32. [31–33], p < 0.001; VAS discomfort 4 [2–6] vs. 6 [2–7] vs. 7 [4–8] vs. 8 [4–10], p = 0.03. VAS discomfort increased with higher absolute humidity (p < 0.01) and temperature (p = 0.007). Higher VAS discomfort was associated with increased VAS dyspnea (p = 0.001). Arterial blood gases, respiratory rate, ΔP_ES, PTP_ES and ΔP_L were similar in all conditions. Overall asynchrony index was similar in all steps, but autotriggering rate was lower during NoH and HME (p = 0.03).

Conclusions

During 1-h sessions of helmet NIV in patients with hypoxemic respiratory failure, a double-tube circuit with no humidification allowed adequate conditioning of inspired gas, optimized comfort and improved patient–ventilator interaction. Use of HHs or HME in this setting resulted in increased discomfort due to excessive heat and humidity in the interface, which was associated with more intense dyspnea.

Trail Registration Registered on clinicaltrials.gov (NCT02875379) on August 23rd, 2016.

Helmet NIV in Acute Hypoxemic Respiratory Failure due to COVID-19: Change in PaO2/FiO2 Ratio a Predictor of Success

In acute respiratory failure due to severe coronavirus disease 2019 (COVID-19) pneumonia, mechanical ventilation remains challenging and may result in high mortality. The use of noninvasive ventilation (NIV) may delay required invasive ventilation, increase adverse outcomes, and have a potential aerosol risk to caregivers. Data of 30 patients were collected from patient files and analyzed. Twenty-one (70%) patients were weaned successfully after helmet-NIV support (NIV success group), and invasive mechanical ventilation was required in 9 (30%) patients (NIV failure group) of which 8 (26.7%) patients died. In NIV success vs failure patients, the mean baseline PaO₂/FiO₂ ratio (PFR) (147.2 ± 57.9 vs 156.8 ± 59.0 mm Hg; p = 0.683) and PFR before initiation of helmet (132.3 ± 46.9 vs 121.6 ± 32.7 mm Hg; p = 0.541) were comparable. The NIV success group demonstrated a progressive improvement in PFR in comparison with the failure group at 2 hours (158.8 ± 56.1 vs 118.7 ± 40.7 mm Hg; p = 0.063) and 24 hours (PFR-24) (204.4 ± 94.3 vs 121.3 ± 32.6; p = 0.016). As predictor variables, PFR-24 and change (delta) in PFR at 24 hours from baseline or helmet initiation (dPFR-24) were significantly associated with NIV success in univariate analysis but similar significance could not be reflected in multivariate analysis perhaps due to a small sample size of the study. The PFR-24 cutoff of 161 mm Hg and dPFR-24 cutoff of -1.44 mm Hg discriminate NIV success and failure groups with the area under curve (confidence interval) of 0.78 (0.62-0.95); p = 0.015 and 0.74 (0.55-0.93); p = 0.039, respectively. Helmet interface NIV may be a safe and effective tool for the management of patients with severe COVID-19 pneumonia with acute respiratory failure. More studies are needed to further evaluate the role of helmet NIV especially in patients with initial PFR <150 mm Hg to define PFR/dPFR cutoff at the earliest time point for prediction of helmet-NIV success. How to cite this article Jha OK, Kumar S, Mehra S, Sircar M, Gupta R. Helmet NIV in Acute Hypoxemic Respiratory Failure due to COVID-19: Change in PaO₂/FiO₂ Ratio a Predictor of Success. Indian J Crit Care Med 2021;25(10):1137-1146.

Efficacy of non-invasive and invasive respiratory management strategies in adult patients with acute hypoxaemic respiratory failure: a systematic review and network meta-analysis

Background

Although non-invasive respiratory management strategies have been implemented to avoid intubation, patients with de novo acute hypoxaemic respiratory failure (AHRF) are high risk of treatment failure. In the previous meta-analyses, the effect of non-invasive ventilation was not evaluated according to ventilation modes in those patients. Furthermore, no meta-analyses comparing non-invasive respiratory management strategies with invasive mechanical ventilation (IMV) have been reported. We performed a network meta-analysis to compare the efficacy of non-invasive ventilation according to ventilation modes with high-flow nasal oxygen (HFNO), standard oxygen therapy (SOT), and IMV in adult patients with AHRF.

Methods

The Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, and Ichushi databases were searched. Studies including adults with AHRF and randomized controlled trials (RCTs) comparing two different respiratory management strategies (continuous positive airway pressure (CPAP), pressure support ventilation (PSV), HFNO, SOT, or IMV) were reviewed.

Results

We included 25 RCTs (3,302 participants: 27 comparisons). Using SOT as the reference, CPAP (risk ratio [RR] 0.55; 95% confidence interval [CI] 0.31–0.95; very low certainty) was associated significantly with a lower risk of mortality. Compared with SOT, PSV (RR 0.81; 95% CI 0.62–1.06; low certainty) and HFNO (RR 0.90; 95% CI 0.65–1.25; very low certainty) were not associated with a significantly lower risk of mortality. Compared with IMV, no non-invasive respiratory management was associated with a significantly lower risk of mortality, although all certainties of evidence were very low. The probability of being best in reducing short-term mortality among all possible interventions was higher for CPAP, followed by PSV and HFNO; IMV and SOT were tied for the worst (surface under the cumulative ranking curve value: 93.2, 65.0, 44.1, 23.9, and 23.9, respectively).

Conclusions

When performing non-invasive ventilation among patients with de novo AHRF, it is important to avoid excessive tidal volume and lung injury. Although pressure support is needed for some of these patients, it should be applied with caution because this may lead to excessive tidal volume and lung injury.

Trial registration protocols.io (Protocol integer ID 49375, April 23, 2021). 10.17504/protocols.io.buf7ntrn.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-021-03835-8.

The COSMIC Bubble Helmet: A Non-Invasive Positive Pressure Ventilation System for COVID-19

Goal: COSMIC Medical, a Vancouver-based open-source volunteer initiative, has designed an accessible, affordable, and aerosol-confining non-invasive positive-pressure ventilator (NIPPV) device, known as the COSMIC Bubble Helmet (CBH). This device is intended for COVID-19 patients with mild-to-moderate acute respiratory distress syndrome. System Design: CBH is composed of thermoplastic polyurethane, which creates a flexible neck seal and transparent hood. This device can be connected to wall oxygen, NIPPVs including Continuous Positive Airway Pressure and Bi-level Positive Airway Pressure, and mechanical ventilators. Discussion: Justification of CBH design components relied on several factors, predominantly the safety and comfort of patients and healthcare providers. Conclusion: CBH has implications within and outside of the pandemic, as an alternative to invasive mechanical ventilation methods. We have experimentally verified that CBH is effective in minimizing aerosolization risks and performs at specified clinical requirements.

The use of head helmets to deliver noninvasive ventilatory support: a comprehensive review of technical aspects and clinical findings

A helmet, comprising a transparent hood and a soft collar, surrounding the patient’s head can be used to deliver noninvasive ventilatory support, both as continuous positive airway pressure and noninvasive positive pressure ventilation (NPPV), the latter providing active support for inspiration. In this review, we summarize the technical aspects relevant to this device, particularly how to prevent CO₂ rebreathing and improve patient–ventilator synchrony during NPPV. Clinical studies describe the application of helmets in cardiogenic pulmonary oedema, pneumonia, COVID-19, postextubation and immune suppression. A section is dedicated to paediatric use. In summary, helmet therapy can be used safely and effectively to provide NIV during hypoxemic respiratory failure, improving oxygenation and possibly leading to better patient-centred outcomes than other interfaces.

Helmet Non-Invasive Ventilation for COVID-19 Patients (Helmet-COVID): study protocol for a multicentre randomised controlled trial

INTRODUCTION

Non-invasive ventilation (NIV) delivered by helmet has been used for respiratory support of patients with acute hypoxaemic respiratory failure due to COVID-19 pneumonia. The aim of this study was to compare helmet NIV with usual care versus usual care alone to reduce mortality.

METHODS AND ANALYSIS

This is a multicentre, pragmatic, parallel randomised controlled trial that compares helmet NIV with usual care to usual care alone in a 1:1 ratio. A total of 320 patients will be enrolled in this study. The primary outcome is 28-day all-cause mortality. The primary outcome will be compared between the two study groups in the intention-to-treat and per-protocol cohorts. An interim analysis will be conducted for both safety and effectiveness.

ETHICS AND DISSEMINATION

Approvals are obtained from the institutional review boards of each participating institution. Our findings will be published in peer-reviewed journals and presented at relevant conferences and meetings.

TRIAL REGISTRATION NUMBER

NCT04477668.

The CircumVent Project: a CPAP/O2 helmet solution for non-invasive ventilation using an implementation research framework

Background

Acute respiratory failure, a major cause of death in COVID-19, is managed with high-flow oxygen therapy via invasive mechanical ventilation. In resource-limited settings like Nigeria, the shortage of ventilators and oxygen supply makes this option challenging. Evidence-based non-invasive alternatives to mechanical ventilation such as the use of continuous positive airway pressure (CPAP) devices exist, but there have been concerns that non-invasive ventilation may expose healthcare workers to infection from aerosolized dispersion of SARS-CoV-2. We propose to evaluate the feasibility, adaptability and acceptability of a CPAP/O₂ helmet solution for non-invasive ventilation among patients with COVID-19 and health workers in eight COVID-19 treatment and isolation centers in Nigeria.

Methods

The study will occur in 4 stages: (1) convene a Steering Committee of key stakeholders and recruit implementation sites; (2) use the integrated Promoting Action on Research Implementation in Health Services (i-PARiHS) framework to guide a needs assessment of treatment centers’ capacity to use high-flow oxygen therapy to treat COVID-19 patients and utilize the findings to develop an implementation strategy for the use of a CPAP/O₂ helmet solution; (3) build infrastructure to support training and data monitoring processes and to develop implementation protocols to evaluate the adaptability of the strategy for the use of the CPAP/O₂ helmet; and (4) train health workers, distribute a CPAP/O₂ helmet solution for non-invasive ventilation, pilot test the implementation strategy, and assess feasibility of its use and acceptability that includes monitoring altered risk of SARS-CoV-2 infection among healthcare workers.

Discussion

The CPAP/O₂ helmet solution for non-invasive ventilation in Nigeria can serve as a scalable model for resource-poor countries, and beyond the COVID-19 pandemic, has the potential to be deployed for the treatment of pneumonia and other respiratory diseases.

Trial registration

NCT04929691. Registered June 18, 2021—retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT04929691

Helmet non-invasive ventilation compared to facemask non-invasive ventilation and high flow nasal cannula in acute respiratory failure: a systematic review and meta-analysis

BACKGROUND

Although small randomised controlled trials (RCTs) and observational studies have examined helmet non-invasive ventilation (NIV), uncertainty remains regarding its role. We conducted a systematic review and meta-analysis to examine the effect of helmet NIV compared to facemask NIV or high flow nasal cannula (HFNC) in acute respiratory failure.

METHODS

We searched multiple databases to identify RCTs and observational studies reporting on at least one of mortality, intubation, ICU length of stay, NIV duration, complications, or comfort with NIV therapy. We assessed study risk of bias (ROB) using the Cochrane ROB tool for RCTs and the Ottawa-Newcastle scale for observational studies and rated certainty of pooled evidence using GRADE.

RESULTS

We separately pooled data from 16 RCTs (n=949) and 8 observational studies (n=396). Compared to facemask NIV, based on low certainty evidence, helmet NIV may reduce mortality (relative risk (RR) 0.56, 95% confidence interval (CI) (0.33 to 0.95)), and intubation (RR 0.35, 95% CI (0.22 to 0.56)) in both hypoxic and hypercapnic respiratory failure but may have no effect on duration of NIV. There was an uncertain effect of helmet on ICU length of stay and development of pressure sores. Data from observational studies was consistent with the foregoing findings but of lower certainty. Based on low and very low certainty data, helmet NIV may reduce intubation compared to HFNC, but its effect on mortality is uncertain.

CONCLUSION

Compared to facemask NIV, helmet NIV may reduce mortality and intubation; however, the effect of helmet compared to HFNC remains uncertain.

Noninvasive Respiratory Support

Despite its life-saving nature, invasive mechanical ventilation does not come without risk, and the avoidance of invasive mechanical ventilation is the primary goal of noninvasive respiratory support. Noninvasive respiratory support in the form of continuous or bi-level positive airway pressure were considered the only viable options to accomplish this for many years. Innovation and research have led to high-flow nasal cannula being added to the list of specialized therapies clinically shown to reduce escalation of care and intubation rates in patients presenting with acute respiratory failure. The amount of research being performed in this clinical space is impressive, to say the least, and it is rapidly evolving. It is the responsibility of the clinicians trained to use these therapies in the management of respiratory failure to understand the currently available evidence, benefits, and risks associated with the type of noninvasive respiratory support being used to treat our patients.

The roles of noninvasive mechanical ventilation with helmet in patients with acute respiratory failure: A systematic review and meta-analysis

Objective

To compare the safety and effectiveness between helmet and face mask noninvasive mechanical ventilation (NIMV) in patients with acute respiratory failure (ARF).

Methods

English databases included PubMed, EMBASE, Cochrane Central Register of Controlled Trials and Web of Science. Chinese databases involved Wanfang Data, China Knowledge Resource Integrated Database and Chinese Biological Medicine Database. Randomized controlled trials (RCTs) comparing helmet and face mask NIMV for patients with ARF were searched. Meta-analysis was performed using Review manager 5.1.0.

Results

Twelve trials with a total of 569 patients were eligible. Our meta-analysis showed that, comparing with face mask, helmet could significantly decrease the incidences of intolerance [risk ratio (RR) 0.19; 95% confidence interval (CI) 0.09−0.39], facial skin ulcer (RR 0.19; 95% CI 0.08−0.43) and aerophagia (RR 0.15; 95% CI 0.06−0.37), reduce respiratory rate [mean difference (MD) -3.10; 95% CI -4.85 to -1.34], intubation rate (RR 0.39; 95% CI 0.26−0.59) and hospital mortality (RR 0.62; 95% CI 0.39−0.99) in patients with ARF, and improve oxygenation index in patients with hypoxemic ARF (MD 55.23; 95% CI 31.37−79.09). However, subgroupanalysis for hypercapnic ARF revealed that PaCO₂ was significantly reduced in face mask group compared with helmet group (MD 5.34; 95% CI 3.41−7.27).

Conclusion

NIMV with helmet can improve the patient’s tolerance, reduce adverse events, increase oxygenation effect, and decrease intubation rate and hospital mortality comparing to face mask. However, the low number of patients from included studies may preclude strong conclusions. Large RCTs are still needed to provide more robust evidence.

COVID-19 pneumonia: a tailor-made dress for a Down syndrome patient

We report here a case of coronavirus disease 2019 pneumonia in a 40-year-old Caucasian woman with Down syndrome admitted to the Internal Medicine Unit. She was initially treated with hydroxychloroquine and azithromycin. When respiratory conditions dramatically worsened, she was not admitted to the intensive care unit because of impaired cognitive function. Thus helmet-based continuous positive airway pressure was started. The respiratory conditions progressively improved, reaching spontaneous breathing.

Use of Helmet CPAP in COVID-19 - A practical review

Helmet CPAP (H-CPAP) has been recommended in many guidelines as a noninvasive respiratory support during COVID-19 pandemic in many countries around the world. It has the least amount of particle dispersion and air contamination among all noninvasive devices and may mitigate the ICU bed shortage during a COVID surge as well as a decreased need for intubation/mechanical ventilation. It can be attached to many oxygen delivery sources. The MaxVenturi setup is preferred as it allows for natural humidification, low noise burden, and easy transition to HFNC during breaks and it is the recommended transport set-up. The patients can safely be proned with the helmet. It can also be used to wean the patients from invasive mechanical ventilation. Our article reviews in depth the pathophysiology of COVID-19 ARDS, provides rationale of using H-CPAP, suggests a respiratory failure algorithm, guides through its setup and discusses the issues and concerns around using it.

Neck circumference as reliable predictor of mechanical ventilation support in adult inpatients with COVID-19: A multicentric prospective evaluation

AIMS

COVID-19 is especially severe for elderly subjects with cardiometabolic and respiratory comorbidities. Neck circumference (NC) has been shown to be strongly related to cardiometabolic and respiratory illnesses even after adjustment for body mass index (BMI). We performed a prospective study to investigate the potential of NC to predict the need for invasive mechanical ventilation (IMV) in adult COVID-19 inpatients.

MATERIALS AND METHODS

We prospectively and consecutively enrolled COVID-19 adult patients admitted to dedicated medical wards of two Italian hospitals from 25 March to 7 April 2020. On admission, clinical, biochemical and anthropometric data, including BMI and NC were collected. As primary outcome measure, the maximum respiratory support received was evaluated. Follow-up time was 30 days from hospital admission.

RESULTS

We enrolled 132 subjects (55.0-75.8 years, 32% female). During the study period, 26 (19.7%) patients underwent IMV. In multivariable logistic regression analyses, after adjusting for age, sex, diabetes, hypertension and COPD, NC resulted independently and significantly associated with IMV risk (adjusted OR 1.260-per 1 cm increase 95% CI:1.120-1.417; P < .001), with a stronger association in the subgroup with BMI ≤30 Kg/m² (adjusted OR 1.526; 95% CI:1.243-1.874; P < .001). NC showed a good discrimination power in predicting patients requiring IMV (AUC 0.783; 95% CI:0.684-0.882; P < .001). In particular, NC > 40.5 cm (>37.5 for females and >42.5 for males) showed a higher and earlier IMV risk compared to subjects with lower NC (Log-rank test: P < .001).

CONCLUSIONS

NC is an easy to measure parameter able to predict the need for IMV in adult COVID-19 inpatients.

Noninvasive ventilation with a helmet in patients with acute respiratory failure caused by chest trauma: a randomized controlled trial

Noninvasive ventilation (NIV) is beneficial in acute respiratory failure (ARF) caused by chest trauma; however, NIV-related complications affect the efficacy. We evaluated whether NIV with helmet decreases the incidence of complications and improves its effects in a single center. Patients with ARF after chest trauma were randomized to receive NIV with helmet or face mask. The primary outcome was the rate of NIV-related complications. Secondary outcomes were PaO₂/FiO₂, patient’s tolerance, intubation rate, length of intensive care unit (ICU) stay, and ICU mortality. The trial was terminated early after an interim analysis with 59 patients. The incidence of complications was lower in the helmet group [10% (3/29) vs 43% (13/30), P = 0.004], and PaO₂/FiO₂s were higher at 1 h and at the end of NIV (253.14 ± 64.74 mmHg vs 216.06 ± 43.86 mmHg, 277.07 ± 84.89 mmHg vs 225.81 ± 63.64 mmHg, P = 0.013 and 0.012) compared with them in face mask group. More patients reported excellent tolerance of the helmet vs face mask after 4 h of NIV [83% (24/29) vs 47% (14/30), P = 0.004] and at the end of NIV [69% (20/29) vs 30% (9/30), P = 0.03]. Differences in intubation rate, ICU stay, and mortality were non-significant (P = 0.612, 0.100, 1.000, respectively). NIV with helmet decreased NIV-related complications, increased PaO₂/FiO₂, and improved tolerance compared with NIV with face mask in patients with chest trauma.

Trial registration: Registered in the Chinese Clinical Trial Registry (ChiCTR1900025915), a WHO International Clinical Trials Registry Platform (http://www.chictr.org.cn/searchprojen.aspx).

Clinical risk factors for mortality in patients with cancer and COVID-19: a systematic review and meta-analysis of recent observational studies

INTRODUCTION

Patients with cancer are more vulnerable to COVID-19 than the general population. Accordingly, it is necessary to identify the risk factors for death in patients with cancer and COVID-19.

METHODS

PubMed, Cochrane Library, and Embase Ovid databases were searched for relevant articles published before July 31^st, 2020. Studies that explored the risk factors for mortality were included. The effect size was relative risk (RR) and 95% confidence interval (CI).

RESULTS

We included 17 observational studies involving 3268 patients. The pooled mortality was 24.8%. Male gender, age above 65 years, and comorbidities (especially hypertension and COPD) were risk factors for death (RR 1.16, 1.27, 1.12; 95% CI 0.7-1.95, 1.08-1.49, 1.04-1.2; P = 0.006, 0.004, and 0.002, respectively). Recent anti-cancer treatments did not increase mortality (P > 0.05). Dyspnea, cough, and sputum canused an elevated risk of death (P < 0.05). Antibiotics, glucocorticoids, interferons, invasive ventilation, and complications were associated with a high probability of death (P < 0.05).

CONCLUSIONS

Various demographic and clinical characteristics, such as male gender, advanced age, comorbidities, and symptoms, were risk factors for mortality in patients with cancer and COVID-19. Our findings suggest recent anti-cancer treatments do not increase mortality.

Association of Noninvasive Oxygenation Strategies With All-Cause Mortality in Adults With Acute Hypoxemic Respiratory Failure: A Systematic Review and Meta-analysis

IMPORTANCE

Treatment with noninvasive oxygenation strategies such as noninvasive ventilation and high-flow nasal oxygen may be more effective than standard oxygen therapy alone in patients with acute hypoxemic respiratory failure.

OBJECTIVE

To compare the association of noninvasive oxygenation strategies with mortality and endotracheal intubation in adults with acute hypoxemic respiratory failure.

DATA SOURCES

The following bibliographic databases were searched from inception until April 2020: MEDLINE, Embase, PubMed, Cochrane Central Register of Controlled Trials, CINAHL, Web of Science, and LILACS. No limits were applied to language, publication year, sex, or race.

STUDY SELECTION

Randomized clinical trials enrolling adult participants with acute hypoxemic respiratory failure comparing high-flow nasal oxygen, face mask noninvasive ventilation, helmet noninvasive ventilation, or standard oxygen therapy.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently extracted individual study data and evaluated studies for risk of bias using the Cochrane Risk of Bias tool. Network meta-analyses using a bayesian framework to derive risk ratios (RRs) and risk differences along with 95% credible intervals (CrIs) were conducted. GRADE methodology was used to rate the certainty in findings.

MAIN OUTCOMES AND MEASURES

The primary outcome was all-cause mortality up to 90 days. A secondary outcome was endotracheal intubation up to 30 days.

RESULTS

Twenty-five randomized clinical trials (3804 participants) were included. Compared with standard oxygen, treatment with helmet noninvasive ventilation (RR, 0.40 [95% CrI, 0.24-0.63]; absolute risk difference, -0.19 [95% CrI, -0.37 to -0.09]; low certainty) and face mask noninvasive ventilation (RR, 0.83 [95% CrI, 0.68-0.99]; absolute risk difference, -0.06 [95% CrI, -0.15 to -0.01]; moderate certainty) were associated with a lower risk of mortality (21 studies [3370 patients]). Helmet noninvasive ventilation (RR, 0.26 [95% CrI, 0.14-0.46]; absolute risk difference, -0.32 [95% CrI, -0.60 to -0.16]; low certainty), face mask noninvasive ventilation (RR, 0.76 [95% CrI, 0.62-0.90]; absolute risk difference, -0.12 [95% CrI, -0.25 to -0.05]; moderate certainty) and high-flow nasal oxygen (RR, 0.76 [95% CrI, 0.55-0.99]; absolute risk difference, -0.11 [95% CrI, -0.27 to -0.01]; moderate certainty) were associated with lower risk of endotracheal intubation (25 studies [3804 patients]). The risk of bias due to lack of blinding for intubation was deemed high.

CONCLUSIONS AND RELEVANCE

In this network meta-analysis of trials of adult patients with acute hypoxemic respiratory failure, treatment with noninvasive oxygenation strategies compared with standard oxygen therapy was associated with lower risk of death. Further research is needed to better understand the relative benefits of each strategy.

Helmet-based noninvasive ventilation for acute exacerbation of chronic obstructive pulmonary disease: A case report

BACKGROUND

Noninvasive ventilation (NIV) reduces intubation rates, mortalities, and lengths of hospital and intensive care unit stays in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD). Helmet-based NIV is better tolerated than oronasal mask-based ventilation, and thus, allows NIV to be conducted for prolonged periods at higher pressures with minimal air leaks.

CASE SUMMARY

A 73-year-old man with a previous diagnosis of COPD stage 4 was admitted to our medical intensive care unit with chief complaints of cough, sputum, and dyspnea of several days’ duration. For 10 mo, he had been on oxygen at home by day and had used an oronasal mask-based NIV at night. At intensive care unit admission, he breathed using respiratory accessory muscles. Hypercapnia and signs of infection were detected, and infiltration was observed in the right lower lung field by chest radiography. Thus, we diagnosed AECOPD by community-acquired pneumonia. After admission, respiratory distress steadily deteriorated and invasive mechanical ventilation became necessary. However, the patient refused this option, and thus, we selected helmet-based NIV as a salvage treatment. After 3 d of helmet-based NIV, his consciousness level and hypercapnia recovered to his pre-hospitalization level.

CONCLUSION

Helmet-based NIV could be considered as a salvage treatment when AECOPD patients refuse invasive mechanical ventilation and oronasal mask-based NIV is ineffective.

Physiological Comparison of High-Flow Nasal Cannula and Helmet Noninvasive Ventilation in Acute Hypoxemic Respiratory Failure

Rationale: High-flow nasal cannula (HFNC) and helmet noninvasive ventilation (NIV) are used for the management of acute hypoxemic respiratory failure.Objectives: Physiological comparison of HFNC and helmet NIV in patients with hypoxemia.Methods: Fifteen patients with hypoxemia with Pa_O2/Fi_O2 < 200 mm Hg received helmet NIV (positive end-expiratory pressure ≥ 10 cm H₂O, pressure support = 10-15 cm H₂O) and HFNC (50 L/min) in randomized crossover order. Arterial blood gases, dyspnea, and comfort were recorded. Inspiratory effort was estimated by esophageal pressure (Pes) swings. Pes-simplified pressure-time product and transpulmonary pressure swings were measured.Measurements and Main Results: As compared with HFNC, helmet NIV increased Pa_O2/Fi_O2 (median [interquartile range]: 255 mm Hg [140-299] vs. 138 [101-172]; P = 0.001) and lowered inspiratory effort (7 cm H₂O [4-11] vs. 15 [8-19]; P = 0.001) in all patients. Inspiratory effort reduction by NIV was linearly related to inspiratory effort during HFNC (r = 0.84; P < 0.001). Helmet NIV reduced respiratory rate (24 breaths/min [23-31] vs. 29 [26-32]; P = 0.027), Pes-simplified pressure-time product (93 cm H₂O ⋅ s ⋅ min^-1 [43-138] vs. 200 [168-335]; P = 0.001), and dyspnea (visual analog scale 3 [2-5] vs. 8 [6-9]; P = 0.002), without affecting Pa_CO2 (P = 0.80) and comfort (P = 0.50). In the overall cohort, transpulmonary pressure swings were not different between treatments (NIV = 18 cm H₂O [14-21] vs. HFNC = 15 [8-19]; P = 0.11), but patients exhibiting lower inspiratory effort on HFNC experienced increases in transpulmonary pressure swings with helmet NIV. Higher transpulmonary pressure swings during NIV were associated with subsequent need for intubation.Conclusions: As compared with HFNC in hypoxemic respiratory failure, helmet NIV improves oxygenation, reduces dyspnea, inspiratory effort, and simplified pressure-time product, with similar transpulmonary pressure swings, Pa_CO2, and comfort.

Noninvasive approach for de novo acute hypoxemic respiratory failure: noninvasive ventilation, high-flow nasal cannula, both or none?

PURPOSE OF REVIEW

To summarize the recent evidence regarding the use of noninvasive strategies for de novo acute hypoxemic respiratory failure (AHRF).

RECENT FINDINGS

New guidelines for the use of noninvasive ventilation (NIV) in acute respiratory failure have been published. In parallel, high-flow nasal cannula (HFNC) is an emerging noninvasive strategy for AHRF patients. Although some have cautioned against the use of NIV in AHRF, new encouraging data about the use of a helmet interface for NIV in acute respiratory distress syndrome may overcome the limitations of facemask NIV.

SUMMARY

In the last two decades, the use of NIV and HFNC in patients with AHRF has considerably expanded, changing the paradigm of management of AHRF. Choice of each technique should be based according to centre experience and patient tolerability. However, when using noninvasive strategies for AHRF, it is crucial to predefine specific criteria for intubation and monitor patients closely for early detection of clinical deterioration to avoid delayed intubation.

ISCCM Guidelines for the Use of Non-invasive Ventilation in Acute Respiratory Failure in Adult ICUs

A. ACUTE HYPERCAPNIC RESPIRATORY FAILURE A1. Acute Exacerbation of COPD: Recommendations: NIV should be used in management of acute exacerbation of COPD in patients with acute or acute-on-chronic respiratory acidosis (pH = 7.25-7.35). (1A) NIV should be attempted in patients with acute exacerbation of COPD (pH <7.25 & PaCO2 ≥ 45) before initiating invasive mechanical ventilation (IMV) except in patients requiring immediate intubation. (2A). Lower the pH higher the chance of failure of NIV. (2B) NIV should not to be used routinely in normo- or mildly hyper-capneic patients with acute exacerbation of COPD, without acidosis (pH > 7.35). (2B) A2. NIV in ARF due to Chest wall deformities/Neuromuscular diseases: Recommendations: NIV may be used in patients of ARF due to chest wall deformity/Neuromuscular diseases. (PaCO2 ≥ 45) (UPP) A3. NIV in ARF due to Obesity hypoventilation syndrome (OHS): Recommendations: NIV may be used in AHRF in OHS patients when they present with acute hypercapnic or acute on chronic respiratory failure (pH 45). (3B) NIV/CPAP may be used in obese, hypercapnic patients with OHS and/or right heart failure in the absence of acidosis. (UPP) B.

NIV IN ACUTE HYPOXEMIC RESPIRATORY FAILURE

B1. NIV in Acute Cardiogenic Pulmonary Oedema: Recommendations: NIV is recommended in hospital patients with ARF, due to Cardiogenic pulmonary edema. (1A). NIV should be used in patients with acute heart failure/ cardiogenic pulmonary edema, right from emergency department itself. (1B) Both CPAP and BiPAP modes are safe and effective in patients with cardiogenic pulmonary edema. (1A). However, BPAP (NIV-PS) should be preferred in cardiogenic pulmonary edema with hypercapnia. (3A) B2. NIV in acute hypoxemic respiratory failure: Recommendations: NIV may be used over conventional oxygen therapy in mild early acute hypoxemic respiratory failure (P/F ratio <300 and >200 mmHg), under close supervision. (2B) We strongly recommend against a trial of NIV in patients with acute hypoxemic failure with P/F ratio <150. (2A) B3. NIV in ARF due to Chest Trauma: Recommendations: NIV may be used in traumatic flail chest along with adequate pain relief. (3B) B4. NIV in Immunocompromised Host: Recommendations: In Immunocompromised patients with early ARF, we may consider NIV over conventional oxygen. (2B). B5. NIV in Palliative Care: Recommendations: We strongly recommend use of NIV for reducing dyspnea in palliative care setting. (2A) B6. NIV in post-operative cases: Recommendations: NIV should be used in patients with post-operative acute respiratory failure. (2A) B6a. NIV in abdominal surgery: Recommendations: NIV may be used in patients with ARF following abdominal surgeries. (2A) B6b. NIV in bariatric surgery: Recommendations: NIV may be used in post-bariatric surgery patients with pre-existent OSA or OHS. (3A) B6c. NIV in Thoracic surgery: Recommendations: In cardiothoracic surgeries, use of NIV is recommended post operatively for acute respiratory failure to improve oxygenation and reduce chance of reintubation. (2A) NIV should not be used in patients undergoing esophageal surgery. (UPP) B6d. NIV in post lung transplant: Recommendations: NIV may be used for shortening weaning time and to avoid re-intubation following lung transplantation. (2B) B7. NIV during Procedures (ETI/Bronchoscopy/TEE/Endoscopy): Recommendations: NIV may be used for pre-oxygenation before intubation. (2B) NIV with appropriate interface may be used in patients of ARF during Bronchoscopy/Endoscopy to improve oxygenation. (3B) B8. NIV in Viral Pneumonitis ARDS: Recommendations: NIV cannot be considered as a treatment of choice for patients with acute respiratory failure with H1N1 pneumonia. However, it may be reasonable to use NIV in selected patients with single organ involvement, in a strictly controlled environment with close monitoring. (2B) B9. NIV and Acute exacerbation of Pulmonary Tuberculosis: Recommendations: Careful use of NIV in patients with acute Tuberculosis may be considered, with effective infection control precautions to prevent air-borne transmission. (3B) B10. NIV after planned extubation in high risk patients: Recommendation: We recommend that NIV may be used to wean high risk patients from invasive mechanical ventilation as it reduces re-intubation rate. (2B) B11. NIV for respiratory distress post extubation: Recommendations: We recommend that NIV therapy should not be used to manage respiratory distress post-extubation in high risk patients. (2B) C.

APPLICATION OF NIV

Recommendation: Choice of mode should be mainly decided by factors like disease etiology and severity, the breathing effort by the patient and the operator familiarity and experience. (UPP) We suggest using flow trigger over pressure triggering in assisted modes, as it provides better patient ventilator synchrony. Especially in COPD patients, flow triggering has been found to benefit auto PEEP. (3B) D.

MANAGEMENT OF PATIENT ON NIV

D1. Sedation: Recommendations: A non-pharmacological approach to calm the patient (Reassuring the patient, proper environment) should always be tried before administrating sedatives. (UPP) In patients on NIV, sedation may be used with extremely close monitoring and only in an ICU setting with lookout for signs of NIV failure. (UPP) E.

EQUIPMENT

Recommendations: We recommend that portable bilevel ventilators or specifically designed ICU ventilators with non-invasive mode should be used for delivering Non-invasive ventilation in critically ill patients. (UPP) Both critical care ventilators with leak compensation and bi-level ventilators have been equally effective in decreasing the WOB, RR, and PaCO2. (3B) Currently, Oronasal mask is the most preferred interface for non-invasive ventilation for acute respiratory failure. (3B) F.

WEANING

Recommendations: We recommend that weaning from NIV may be done by a standardized protocol driven approach of the unit. (2B) How to cite this article: Chawla R, Dixit SB, Zirpe KG, Chaudhry D, Khilnani GC, Mehta Y, et al. ISCCM Guidelines for the Use of Non-invasive Ventilation in Acute Respiratory Failure in Adult ICUs. Indian J Crit Care Med 2020;24(Suppl 1):S61-S81.

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.

How should we monitor patients with acute respiratory failure treated with noninvasive ventilation?

Noninvasive ventilation (NIV) is currently one of the most commonly used support methods in hypoxaemic and hypercapnic acute respiratory failure (ARF). With advancing technology and increasing experience, not only are indications for NIV getting broader, but more severe patients are treated with NIV. Depending on disease type and clinical status, NIV can be applied both in the general ward and in high-dependency/intensive care unit settings with different environmental opportunities. However, it is important to remember that patients with ARF are always very fragile with possible high mortality risk. The delay in recognition of unresponsiveness to NIV, progression of respiratory failure or new-onset complications may result in devastating and fatal outcomes. Therefore, it is crucial to understand that timely action taken according to monitoring variables is one of the key elements for NIV success. The purpose of this review is to outline basic and advanced monitoring techniques for NIV during an ARF episode.

What Can We Apply to Manage Acute Exacerbation of Chronic Obstructive Pulmonary Disease with Acute Respiratory Failure?

Acute exacerbation(s) of chronic obstructive pulmonary disease (AECOPD) tend to be critical and debilitating events leading to poorer outcomes in relation to chronic obstructive pulmonary disease (COPD) treatment modalities, and contribute to a higher and earlier mortality rate in COPD patients. Besides pro-active preventative measures intended to obviate acquisition of AECOPD, early recovery from severe AECOPD is an important issue in determining the long-term prognosis of patients diagnosed with COPD. Updated GOLD guidelines and recently published American Thoracic Society/European Respiratory Society clinical recommendations emphasize the importance of use of pharmacologic treatment including bronchodilators, systemic steroids and/or antibiotics. As a non-pharmacologic strategy to combat the effects of AECOPD, noninvasive ventilation (NIV) is recommended as the treatment of choice as this therapy is thought to be most effective in reducing intubation risk in patients diagnosed with AECOPD with acute respiratory failure. Recently, a few adjunctive modalities, including NIV with helmet and helium-oxygen mixture, have been tried in cases of AECOPD with respiratory failure. As yet, insufficient documentation exists to permit recommendation of this therapy without qualification. Although there are too few findings, as yet, to allow for regular andr routine application of those modalities in AECOPD, there is anecdotal evidence to indicate both mechanical and physiological benefits connected with this therapy. High-flow nasal cannula oxygen therapy is another supportive strategy which serves to improve the symptoms of hypoxic respiratory failure. The therapy also produced improvement in ventilatory variables, and it may be successfully applied in cases of hypercapnic respiratory failure. Extracorporeal carbon dioxide removal has been successfully attempted in cases of adult respiratory distress syndrome, with protective hypercapnic ventilatory strategy. Nowadays, it is reported that it was also effective in reducing intubation in AECOPD with hypercapnic respiratory failure. Despite the apparent need for more supporting evidence, efforts to improve efficacy of NIV have continued unabated. It is anticipated that these efforts will, over time, serve toprogressively decrease the risk of intubation and invasive mechanical ventilation in cases of AECOPD with acute respiratory failure.

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.

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.

High-flow nasal cannula support therapy: new insights and improving performance

This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2017. Other selected articles can be found online at http://ccforum.com/series/annualupdate2017 . Further information about the Annual Update in Intensive Care and Emergency Medicine is available from http://www.springer.com/series/8901 .