Noninvasive ventilation for acute respiratory distress syndrome: the importance of ventilator settings

Management of Hantavirus Cardiopulmonary Syndrome in Critical Care Transport: A Review

In 1993, the Southwest found itself staring down a disease then known as "unexplained adult respiratory syndrome." During the outbreak, 12 of 23 known patients died. What we now recognize as hantavirus cardiopulmonary syndrome still remains a rare and deadly disease. Although no cure exists, modern supportive techniques such as extracorporeal membrane oxygenation have increased survival among these patients. Early diagnosis has become the primary factor in patient survival. The initial presentation of hantavirus is similar to acute respiratory distress syndrome, necessitating a high index of suspicion to afford the patient the best chance of survival. Diagnosis is further complicated by prolonged and nonspecific incubation periods making it difficult to pinpoint an exposure. Familiarizing oneself with common clinical presentations, diagnostic strategies, and testing is the best way to increase patient survival. Because hantavirus has a predilection for rural areas, transport to a tertiary facility is paramount to provide the resources necessary to care for these complex patients. Rapid sequence intubation, although common in airway-compromised patients, could prove fatal in the setting of the severe hemodynamic instability found in hantavirus cardiopulmonary syndrome. Anticipation of significant pressor use and fluid administration could likely mean the difference in patient mortality during transport.

[Psychological aspects during and after intensive care treatment of ARDS]

Approximately 10% of all patients requiring intensive care develop acute respiratory distress syndrome (ARDS). The COVID-19 pandemic led to an accumulation of patients with severe ARDS. The experience of this severe respiratory failure is accompanied by feelings of existential anxiety in many patients.The complexity of the challenges and stresses that the disease and its treatment pose for the ARDS patient require an early multiprofessional approach to treatment already during intensive care. Psychological approaches are suitable to support the patient as well as the relatives in coping with the disease and to minimise risks for potential subsequent stress. Despite the long-term impairments of patients who have survived ARDS and the resulting need for follow-up care, suitable multimodal follow-up care concepts and the necessary care structures are still lacking. The article presents the psychological support during and after the intensive care treatment of ARDS.

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.

Randomized clinical trial comparing helmet continuous positive airway pressure (hCPAP) to facemask continuous positive airway pressure (fCPAP) for the treatment of acute respiratory failure in the emergency department

STUDY OBJECTIVE

To determine whether non-invasive ventilation (NIV) delivered by helmet continuous positive airway pressure (hCPAP) is non-inferior to facemask continuous positive airway pressure (fCPAP) in patients with acute respiratory failure in the emergency department (ED).

METHODS

Non-inferiority randomized, clinical trial involving patients presenting with acute respiratory failure conducted in the ED of a local hospital. Participants were randomly allocated to receive either hCPAP or fCPAP as per the trial protocol. The primary endpoint was respiratory rate reduction. Secondary endpoints included discomfort, improvement in Dyspnea and Likert scales, heart rate reduction, arterial blood oxygenation, partial pressure of carbon dioxide (PaCO2), dryness of mucosa and intubation rate.

RESULTS

224 patients were included and randomized (113 patients to hCPAP, 111 to fCPAP). Both techniques reduced respiratory rate (hCPAP: from 33.56 ± 3.07 to 25.43 ± 3.11 bpm and fCPAP: from 33.46 ± 3.35 to 27.01 ± 3.19 bpm), heart rate (hCPAP: from 114.76 ± 15.5 to 96.17 ± 16.50 bpm and fCPAP: from 115.07 ± 14.13 to 101.19 ± 16.92 bpm), and improved dyspnea measured by both the Visual Analogue Scale (hCPAP: from 16.36 ± 12.13 to 83.72 ± 12.91 and fCPAP: from 16.01 ± 11.76 to 76.62 ± 13.91) and the Likert scale. Both CPAP techniques improved arterial oxygenation (PaO₂ from 67.72 ± 8.06 mmHg to 166.38 ± 30.17 mmHg in hCPAP and 68.99 ± 7.68 mmHg to 184.49 ± 36.38 mmHg in fCPAP) and the PaO2:FiO2 (Partial pressure of arterial oxygen: Fraction of inspired oxygen) ratio from 113.6 ± 13.4 to 273.4 ± 49.5 in hCPAP and 115.0 ± 12.9 to 307.7 ± 60.9 in fCPAP. The intubation rate was lower with hCPAP (4.4% for hCPAP versus 18% for fCPAP, absolute difference -13.6%, p = 0.003). Discomfort and dryness of mucosa were also lower with hCPAP.

CONCLUSION

In patients presenting to the ED with acute cardiogenic pulmonary edema or decompensated COPD, hCPAP was non-inferior to fCPAP and resulted in greater comfort levels and lower intubation rate.

The Impact of Preintubation Noninvasive Ventilation on Outcomes in Pediatric Acute Respiratory Distress Syndrome

OBJECTIVES

There is evidence that noninvasive ventilation decreases the need for invasive mechanical ventilation. However, children with pediatric acute respiratory distress syndrome who fail noninvasive ventilation may have worse outcomes than those who are intubated without exposure to noninvasive ventilation. Our objective was to evaluate the impact of preintubation noninvasive ventilation on children with pediatric acute respiratory distress syndrome.

DESIGN

Secondary analysis of data from the Randomized Evaluation of Sedation Titration for Respiratory Failure trial.

SETTING

Thirty-one PICUs in the United States.

PATIENTS

Children 2 weeks to 17 years old with pediatric acute respiratory distress syndrome receiving invasive mechanical ventilation, excluding those admitted with tracheostomies.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of 2,427 subjects receiving invasive mechanical ventilation, preintubation noninvasive ventilation was used in 995 (41%). Compared with subjects without preintubation noninvasive ventilation use, subjects with preintubation noninvasive ventilation use were more likely to have a history of seizures (10% vs 8%; p = 0.04) or cancer (11% vs 6%; p < 0.001) and have moderate or severe pediatric acute respiratory distress syndrome by the end of their first full day of invasive mechanical ventilation (68% vs 60%; p < 0.001). Adjusting for age, severity of illness on PICU admission, and baseline functional status, preintubation noninvasive ventilation use resulted in longer invasive mechanical ventilation duration (median 7.0 vs 6.0 d), longer PICU (10.8 vs 8.9 d), and hospital (17 vs 14 d) lengths of stay, and higher 28-day (5% vs 4%) and 90-day (8% vs 5%) inhospital mortalities (all comparisons p < 0.001). Longer duration of noninvasive ventilation before intubation was associated with worse outcomes.

CONCLUSIONS

In children with pediatric acute respiratory distress syndrome, preintubation noninvasive ventilation use is associated with worse outcomes when compared with no preintubation noninvasive ventilation use. These data can be used to inform the design of clinical studies to evaluate best noninvasive ventilation practices in children with pediatric acute respiratory distress syndrome.

Auxiliary role of mesenchymal stem cells as regenerative medicine soldiers to attenuate inflammatory processes of severe acute respiratory infections caused by COVID-19

Acute respiratory infections as one of the most common problems of healthcare systems also can be considered as an important reason for worldwide morbidity and mortality from infectious diseases. Coronaviruses are a group of well-known respiratory viruses that can cause acute respiratory infections. At the current state, the 2019 novel coronavirus is cited as the most worldwide problematic agent for the respiratory system. According to investigations, people with old age and underlying diseases are at higher risk of 2019 novel coronavirus infection. Indeed, they may show a severe form of the disease (with severe acute respiratory infections). Based on the promising role of cell therapy and regenerative medicine approaches in the treatment of several life-threatening diseases, it seems that applying cell-based approaches can also be a hopeful strategy for improving subjects with severe acute respiratory infections caused by the 2019 novel coronavirus. Herein, due to the amazing effects of mesenchymal stem cells in the treatment of various diseases, this review focuses on the auxiliary role of mesenchymal stem cells to reduce inflammatory processes of acute respiratory infections caused by the 2019 novel coronavirus.

Non-invasive ventilation for acute respiratory failure: pressure support ventilation vs. pressure-controlled ventilation

Background

The best ventilator mode for patients receiving non-invasive ventilation (NIV) has not been clarified. This study compared the effectiveness of two pressure-targeted modes, i.e., pressure support ventilation (PSV) and pressure-controlled ventilation (PCV), in patients receiving NIV.

Methods

This was a prospective multicentre observational study of NIV use for acute respiratory failure (ARF) in adult patients. We compared the two pressure-targeted modes in terms of NIV success and complication rates.

Results

Among 176 patients receiving NIV, 88 patients were included in the study (PCV mode, n=29; PSV mode, n=59). The study population had a median age of 73.0 years and median body mass index of 20.8 kg/m². The applied inspiratory positive airway pressure (IPAP) was higher in patients with PCV than in those with PSV [18.0 cmH₂O (15.0–20.5 cmH₂O) vs. 15.0 cmH₂O (12.0–17.0 cmH₂O), respectively, P=0.001]. More patients with PCV received sedatives and experienced dry mouth than those with PSV; however, the incidences of large leaks were low in both groups (n=5 vs. n=2, respectively). With regard to NIV outcomes, 24 (27.2%) patients experienced NIV failure and 13 (14.8%) died in hospital. PSV mode was a significant factor for NIV success [odds ratio (OR), 2.303; 95% confidence interval (CI), 1.216 to 4.360] in multivariate analyses and this association remained significant in a 1:1 matched cohort (n=29 per group).

Conclusions

In contrast to PCV mode, PSV mode was significantly associated with NIV success in the intensive care unit setting, particularly when large leaks were not a major concern. Nevertheless, further well-designed multicenter, protocol-driven randomized controlled trials are warranted.

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.

Mechanical Ventilation during Extracorporeal Membrane Oxygenation in Patients with Acute Severe Respiratory Failure

Conventionally, a substantial number of patients with acute respiratory failure require mechanical ventilation (MV) to avert catastrophe of hypoxemia and hypercapnia. However, mechanical ventilation per se can cause lung injury, accelerating the disease progression. Extracorporeal membrane oxygenation (ECMO) provides an alternative to rescue patients with severe respiratory failure that conventional mechanical ventilation fails to maintain adequate gas exchange. The physiology behind ECMO and its interaction with MV were reviewed. Next, we discussed the timing of ECMO initiation based on the risks and benefits of ECMO. During the running of ECMO, the protective ventilation strategy can be employed without worrying about catastrophic hypoxemia and carbon dioxide retention. There is a large body of evidence showing that protective ventilation with low tidal volume, high positive end-expiratory pressure, and prone positioning can provide benefits on mortality outcome. More recently, there is an increasing popularity on the use of awake and spontaneous breathing for patients undergoing ECMO, which is thought to be beneficial in terms of rehabilitation.