Outcomes of Noninvasive Positive Pressure Ventilation in Acute Respiratory Distress Syndrome and Their Predictors: A National Cohort

Non-invasive support for the hypoxaemic patient

Optimisation of oxygenation strategies in patients with hypoxaemic respiratory failure is a top priority for acute care physicians, as hypoxaemic respiratory failure is one of the leading causes of admission. Various oxygenation methods range from non-invasive face masks to high flow nasal cannulae, which have advantages and disadvantages for this heterogeneous patient group. Focus has turned toward examining the benefits of non-invasive ventilation, as this was heavily researched in resource-limited settings during the COVID-19 pandemic. The oxygenation strategy should be determined on an individualised basis for patients, and with new evidence from the COVID-19 pandemic, providers may now consider placing further emphasis on non-invasive approaches. As non-invasive ventilation continues to be used in increasing frequency, new methods of monitoring patient response, including when to escalate ventilation strategy, will need to be validated.

Noninvasive Ventilation Exposure Prior to Intubation in Pediatric Hematopoietic Cell Transplant Recipients

BACKGROUND

Noninvasive ventilation (NIV) has become more studied in immunocompromised patients. However, it has not been studied in hematopoietic cell transplantation (HCT) recipients, who have higher mortality and higher pulmonary complication rates than other immunocompromised patients. This population may be prone to negative effects from this treatment modality. The aim of this study was to determine whether NIV use is associated with worse outcomes in this vulnerable patient population.

METHODS

A secondary analysis of a retrospective multi-center database was performed. Twelve pediatric ICUs across the United States enrolled HCT subjects from 2009-2014 that were admitted to the pediatric ICU (PICU) with the diagnosis of acute respiratory failure. Subjects exposed to NIV prior to intubation were compared against those not exposed to NIV. Our primary outcome was all-cause mortality at 90 d; secondary outcomes included ventilator-free days (VFD) at 28 d and development of pediatric ARDS. Multivariable logistic and linear regression models were constructed using variables significant on univariable analysis.

RESULTS

Two-hundred eleven subjects were included. Of these, 82 (39%) received NIV prior to intubation. Those that received NIV prior to intubation were older (13 vs 6 y, P < .001) and more commonly diagnosed with respiratory distress (90% vs 74%, P = .004). On multivariable analysis, NIV use prior to intubation was associated with a higher PICU mortality (hazard ratio 1.51 [95% CI 1.18-2.28], P = .02) and fewer VFD at 28 d (β -3.50 [95% CI -6.09 to 0.91], P = .008). Those with NIV exposure prior to intubation also had higher rates of development of pediatric ARDS (95% vs 78%, P = .001).

CONCLUSIONS

In this cohort of children post-HCT, NIV use prior to intubation was associated with worse outcomes. The benefits and risks of NIV in this patient population should be carefully evaluated prior to its use, and careful patient selection is crucial for its optimal utilization.

Managing Severe Hypoxic Respiratory Failure in COVID-19

Purpose of Review

Adult respiratory distress syndrome is a life-threatening complication from severe COVID-19 infection resulting in severe hypoxic respiratory failure. Strategies at improving oxygenation have evolved over the course of the pandemic.

Recent Findings

Although non-invasive respiratory support reduces the need for intubation, a significant number of patients with COVID-19 progress to invasive mechanical ventilation. Once intubated, a lung protective ventilation strategy should be employed that limits tidal volumes to 6 ml/kg of predicted body weight and employs sufficient positive end-expiratory pressure to maximize oxygen delivery while minimizing the fraction of inspired oxygen. Intermittent prone positioning is effective at improving survival, and there is a growing body of evidence that it can be safely performed in spontaneously breathing patients to reduce the need for invasive mechanical ventilation. Inhaled pulmonary vasodilators have not been shown to improve survival or cost-effectiveness in COVID-19 and should be used selectively.

Summary

Finally, the best outcomes are likely achieved at centers with experience at severe ARDS management and protocols for escalation of care.

Influencing factors of noninvasive positive pressure ventilation in the treatment of respiratory failure: a 10-year study in one single center

Background

The utilization of noninvasive positive pressure ventilation (NPPV) is becoming more and more common, especially in patients with acute or chronic respiratory failure. The purpose of our study is to analyze the factors that influence the efficacy of NPPV in the treatment of respiratory failure caused by a variety of etiology.

Methods

From May 2011 to April 2020, patients treated with NPPV during hospitalization in the First Affiliated Hospital of Soochow University were enrolled. According to the clinical outcome of NPPV treatment and whether converted to invasive mechanical ventilation, patients were divided into the success group and the failure group. The clinical data and the characteristics of NPPV application were compared between the two groups.

Results

A total of 3312 patients were enrolled, including 2025 patients in the success group and 1287 patients in the failure group. Univariate analysis suggested that there were no statistical differences in patients' age, gender, use of analgesia and/or sedation, complicated with barotrauma, inspiratory positive airway pressure and expiratory positive airway pressure between the success and failure groups (P > 0.05). However, there were statistically significant differences in serum albumin levels, Ca²⁺ concentration, blood glucose levels, duration of NPPV treatment and length of hospital stay between the success and failure groups (P < 0.05). Multivariate logistic regression analysis indicated that serum albumin levels and duration of NPPV treatment had statistical significance on the therapeutic effect of NPPV (P < 0.05).

Conclusion

Serum albumin levels and duration of NPPV treatment were independent risk factors for the efficacy of NPPV treatment in respiratory failure.

Risk Factors Associated with Mechanical Ventilation in Critical Bronchiolitis

The American Academy of Pediatrics (AAP) recommends supportive care for the management of bronchiolitis. However, patients admitted to the intensive care unit with severe (critical) bronchiolitis define a unique group with varying needs for both non-invasive and invasive respiratory support. Currently, no guidance exists to help clinicians discern who will progress to invasive mechanical support. Here, we sought to identify key clinical features that distinguish pediatric patients with critical bronchiolitis requiring invasive mechanical ventilation from those that did not. We conducted a retrospective cohort study at a tertiary pediatric medical center. Children ≤2 years old admitted to the pediatric intensive care unit (PICU) from January 2015 to December 2019 with acute bronchiolitis were studied. Patients were divided into non-invasive respiratory support (NRS) and invasive mechanical ventilation (IMV) groups; the IMV group was further subdivided depending on timing of intubation relative to PICU admission. Of the 573 qualifying patients, 133 (23%) required invasive mechanical ventilation. Median age and weight were lower in the IMV group, while incidence of prematurity and pre-existing neurologic or genetic conditions were higher compared to the NRS group. Multi-microbial pneumonias were diagnosed more commonly in the IMV group, in turn associated with higher severity of illness scores, longer PICU lengths of stay, and more antibiotic usage. Within the IMV group, those intubated earlier had a shorter duration of mechanical ventilation and PICU length of stay, associated with lower pathogen load and, in turn, shorter antibiotic duration. Taken together, our data reveal that critically ill patients with bronchiolitis who require mechanical ventilation possess high risk features, including younger age, history of prematurity, neurologic or genetic co-morbidities, and a propensity for multi-microbial infections.

Initial emergency department mechanical ventilation strategies for COVID-19 hypoxemic respiratory failure and ARDS

INTRODUCTION

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an emerging viral pathogen that causes the novel coronavirus disease of 2019 (COVID-19) and may result in hypoxemic respiratory failure necessitating invasive mechanical ventilation in the most severe cases.

OBJECTIVE

This narrative review provides evidence-based recommendations for the treatment of COVID-19 related respiratory failure requiring invasive mechanical ventilation.

DISCUSSION

In severe cases, COVID-19 leads to hypoxemic respiratory failure that may meet criteria for acute respiratory distress syndrome (ARDS). The mainstay of treatment for ARDS includes a lung protective ventilation strategy with low tidal volumes (4-8 mL/kg predicted body weight), adequate positive end-expiratory pressure (PEEP), and maintaining a plateau pressure of < 30 cm H₂O. While further COVID-19 specific studies are needed, current management should focus on supportive care, preventing further lung injury from mechanical ventilation, and treating the underlying cause.

CONCLUSIONS

This review provides evidence-based recommendations for the treatment of COVID-19 related respiratory failure requiring invasive mechanical ventilation.

A Rare Case of ARDS Caused by Bupropion Inhalation and Treated with Noninvasive Ventilation

Acute respiratory distress syndrome, characterized by the Berlin criteria, is associated with a high mortality rate. Its treatment includes addressing the underlying etiology, general supportive measures, and achievement of effective oxygenation. New key data indicates that in a subset of patients, noninvasive ventilation techniques can be a therapeutic and equivalent alternative to traditional invasive ventilation. We present a rare case of ARDS triggered by nasal bupropion inhalation and effectively treated with noninvasive positive pressure ventilation resulting in complete resolution.