Effect of Noninvasive Ventilation Delivered by Helmet vs Face Mask on the Rate of Endotracheal Intubation in Patients With Acute Respiratory Distress Syndrome: A Randomized Clinical Trial

A multicenter RCT of noninvasive ventilation in pneumonia-induced early mild acute respiratory distress syndrome

RATIONALE

Our pilot study suggested that noninvasive ventilation (NIV) reduced the need for intubation compared with conventional administration of oxygen on patients with "early" stage of mild acute respiratory distress syndrome (ARDS, PaO₂/FIO₂ between 200 and 300).

OBJECTIVES

To evaluate whether early NIV can reduce the need for invasive ventilation in patients with pneumonia-induced early mild ARDS.

METHODS

Prospective, multicenter, randomized controlled trial (RCT) of NIV compared with conventional administration of oxygen through a Venturi mask. Primary outcome included the numbers of patients who met the intubation criteria.

RESULTS

Two hundred subjects were randomized to NIV (n = 102) or control (n = 98) groups from 21 centers. Baseline characteristics were similar in the two groups. In the NIV group, PaO₂/FIO₂ became significantly higher than in the control group at 2 h after randomization and remained stable for the first 72 h. NIV did not decrease the proportion of patients requiring intubation than in the control group (11/102 vs. 9/98, 10.8% vs. 9.2%, p = 0.706). The ICU mortality was similar in the two groups (7/102 vs. 7/98, 4.9% vs. 3.1%, p = 0.721). Multivariate analysis showed minute ventilation greater than 11 L/min at 48 h was the independent risk factor for NIV failure (OR, 1.176 [95% CI, 1.005-1.379], p = 0.043).

CONCLUSIONS

Treatment with NIV did not reduce the need for intubation among patients with pneumonia-induced early mild ARDS, despite the improved PaO₂/FIO₂ observed with NIV compared with standard oxygen therapy. High minute ventilation may predict NIV failure.

TRIAL REGISTRATION

NCT01581229 . Registered 19 April 2012.

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

Background

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

Results

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

Conclusions

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

Electronic supplementary material

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

Prevention of hospital-acquired pneumonia

PURPOSE OF REVIEW

Hospital-acquired pneumonia (HAP) is the leading cause of death from hospital-acquired infection. Little work has been done on strategies for prevention of HAP. This review aims to describe potential HAP prevention strategies and the evidence supporting them. Oral care and aspiration precautions may attenuate some risk for HAP. Oral and digestive decontamination with antibiotics may be effective but could increase risk for resistant organisms. Other preventive measures, including isolation practices, remain theoretical or experimental.

RECENT FINDINGS

Hospital-acquired pneumonia occurs because of pharyngeal colonization with pathogenic organisms and subsequent aspiration of these pathogens.

SUMMARY

Most potential HAP prevention strategies remain unproven.

High-flow nasal oxygen therapy alone or with non-invasive ventilation in immunocompromised patients admitted to ICU for acute hypoxemic respiratory failure: the randomised multicentre controlled FLORALI-IM protocol

INTRODUCTION

Non-invasive ventilation (NIV) is recommended as first-line therapy in respiratory failure of critically ill immunocompromised patients as it can decrease intubation and mortality rates as compared with standard oxygen. However, its recommendation is only conditional. Indeed, the use of NIV in this setting has been challenged recently based on results of trials finding similar outcomes with or without NIV or even deleterious effects of NIV. To date, NIV has been compared with standard oxygen but not to high-flow nasal oxygen therapy (HFOT) in immunocompromised patients. Several studies have found lower mortality rates using HFOT alone than when using HFOT with NIV sessions in patients with de novo respiratory failure, and even in immunocompromised patients. We are hypothesising that HFOT alone is more effective than HFOT with NIV sessions and reduces mortality of immunocompromised patients with acute hypoxemic respiratory failure.

METHODS AND ANALYSIS

This study is an investigator-initiated, multicentre randomised controlled trial comparing HFOT alone or with NIV in immunocompromised patients admitted to intensive care unit (ICU) for severe acute hypoxemic respiratory failure. Around 280 patients will be randomised with a 1:1 ratio in two groups. The primary outcome is the mortality rate at day 28 after inclusion. Secondary outcomes include the rate of intubation in each group, length of ICU and hospital stay and mortality up to day 180.

ETHICS AND DISSEMINATION

The study has been approved by the ethics committee and patients will be included after informed consent. The results will be submitted for publication in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT02978300.

Non-Invasive Ventilation in Children with Paediatric Acute Respiratory Distress Syndrome

Introduction: Evidence supporting non-invasive ventilation (NIV) in paediatric acute respiratory distress syndrome (PARDS) remains sparse. We aimed to describe characteristics of patients with PARDS supported with NIV and risk factors for NIV failure. Materials and Methods: This is a multicentre retrospective study. Only patients supported on NIV with PARDS were included. Data on epidemiology and clinical outcomes were collected. Primary outcome was NIV failure which was defined as escalation to invasive mechanical ventilation within the first 7 days of PARDS. Patients in the NIV success and failure groups were compared. Results: There were 303 patients with PARDS; 53/303 (17.5%) patients were supported with NIV. The median age was 50.7 (interquartile range: 15.7-111.9) months. The Paediatric Logistic Organ Dysfunction score and oxygen saturation/fraction of inspired oxygen (SF) ratio were 2.0 (1.0-10.0) and 155.0 (119.4-187.3), respectively. Indications for NIV use were increased work of breathing (26/53 [49.1%]) and hypoxia (22/53 [41.5%]). Overall NIV failure rate was 77.4% (41/53). All patients with sepsis who developed PARDS experienced NIV failure. NIV failure was associated with an increased median paediatric intensive care unit stay (15.0 [9.5-26.5] vs 4.5 [3.0-6.8] days; P <0.001) and hospital length of stay (26.0 [17.0-39.0] days vs 10.5 [5.5-22.3] days; P = 0.004). Overall mortality rate was 32.1% (17/53). Conclusion: The use of NIV in children with PARDS was associated with high failure rate. As such, future studies should examine the optimal selection criteria for NIV use in these children. Key words: Bi-level positive airway pressure, Continuous positive airway pressure, Non-invasive ventilation

Predictors of Intubation in Patients With Acute Hypoxemic Respiratory Failure Treated With a Noninvasive Oxygenation Strategy

OBJECTIVES

In patients with acute hypoxemic respiratory failure, noninvasive ventilation and high-flow nasal cannula oxygen are alternative strategies to conventional oxygen therapy. Endotracheal intubation is frequently needed in these patients with a risk of delay, and early predictors of failure may help clinicians to decide early. We aimed to identify factors associated with intubation in patients with acute hypoxemic respiratory failure treated with different noninvasive oxygenation techniques.

DESIGN

Post hoc analysis of a randomized clinical trial.

SETTING

Twenty-three ICUs.

PATIENTS

Patients with a respiratory rate greater than 25 breaths/min and a PaO2/FIO2 ratio less than or equal to 300 mm Hg.

INTERVENTION

Patients were treated with standard oxygen, high-flow nasal cannula oxygen, or noninvasive ventilation.

MEASUREMENT AND MAIN RESULTS

Respiratory variables one hour after treatment initiation. Under standard oxygen, patients with a respiratory rate greater than or equal to 30 breaths/min were more likely to need intubation (odds ratio, 2.76; 95% CI, 1.13-6.75; p = 0.03). One hour after high-flow nasal cannula oxygen initiation, increased heart rate was the only factor associated with intubation. One hour after noninvasive ventilation initiation, a PaO2/FIO2 ratio less than or equal to 200 mm Hg and a tidal volume greater than 9 mL/kg of predicted body weight were independent predictors of intubation (adjusted odds ratio, 4.26; 95% CI, 1.62-11.16; p = 0.003 and adjusted odds ratio, 3.14; 95% CI, 1.22-8.06; p = 0.02, respectively). A tidal volume above 9 mL/kg during noninvasive ventilation remained independently associated with 90-day mortality.

CONCLUSIONS

In patients with acute hypoxemic respiratory failure breathing spontaneously, the respiratory rate was a predictor of intubation under standard oxygen, but not under high-flow nasal cannula oxygen or noninvasive ventilation. A PaO2/FIO2 below 200 mm Hg and a high tidal volume greater than 9 mL/kg were the two strong predictors of intubation under noninvasive ventilation.

Ventilatory support after extubation in critically ill patients

The periextubation period represents a crucial moment in the management of critically ill patients. Extubation failure, defined as the need for reintubation within 2-7 days after a planned extubation, is associated with prolonged mechanical ventilation, increased incidence of ventilator-associated pneumonia, longer intensive care unit and hospital stays, and increased mortality. Conventional oxygen therapy is commonly used after extubation. Additional methods of non-invasive respiratory support, such as non-invasive ventilation and high-flow nasal therapy, can be used to avoid reintubation. The aim of this Review is to describe the pathophysiological mechanisms of postextubation respiratory failure and the available techniques and strategies of respiratory support to avoid reintubation. We summarise and discuss the available evidence supporting the use of these strategies to achieve a tailored therapy for an individual patient at the bedside.

Clinical Nutrition in Critical Care Medicine - Guideline of the German Society for Nutritional Medicine (DGEM)

PURPOSE

Enteral and parenteral nutrition of adult critically ill patients varies in terms of the route of nutrient delivery, the amount and composition of macro- and micronutrients, and the choice of specific, immune-modulating substrates. Variations of clinical nutrition may affect clinical outcomes. The present guideline provides clinicians with updated consensus-based recommendations for clinical nutrition in adult critically ill patients who suffer from at least one acute organ dysfunction requiring specific drug therapy and/or a mechanical support device (e.g., mechanical ventilation) to maintain organ function.

METHODS

The former guidelines of the German Society for Nutritional Medicine (DGEM) were updated according to the current instructions of the Association of the Scientific Medical Societies in Germany (AWMF) valid for a S2k-guideline. According to the S2k-guideline classification, no systematic review of the available evidence was required to make recommendations, which, therefore, do not state evidence- or recommendation grades. Nevertheless, we considered and commented the evidence from randomized-controlled trials, meta-analyses and observational studies with adequate sample size and high methodological quality (until May 2018) as well as from currently valid guidelines of other societies. The liability of each recommendation was described linguistically. Each recommendation was finally validated and consented through a Delphi process.

RESULTS

In the introduction the guideline describes a) the pathophysiological consequences of critical illness possibly affecting metabolism and nutrition of critically ill patients, b) potential definitions for different disease phases during the course of illness, and c) methodological shortcomings of clinical trials on nutrition. Then, we make 69 consented recommendations for essential, practice-relevant elements of clinical nutrition in critically ill patients. Among others, recommendations include the assessment of nutrition status, the indication for clinical nutrition, the timing and route of nutrient delivery, and the amount and composition of substrates (macro- and micronutrients); furthermore, we discuss distinctive aspects of nutrition therapy in obese critically ill patients and those treated with extracorporeal support devices.

CONCLUSION

The current guideline provides clinicians with up-to-date recommendations for enteral and parenteral nutrition of adult critically ill patients who suffer from at least one acute organ dysfunction requiring specific drug therapy and/or a mechanical support device (e.g., mechanical ventilation) to maintain organ function. The period of validity of the guideline is approximately fixed at five years (2018-2023).

Noninvasive ventilation versus oxygen therapy in patients with acute respiratory failure

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Optimal Ventilator Strategies in Acute Respiratory Distress Syndrome

Mechanical ventilation practices in patients with acute respiratory distress syndrome (ARDS) have progressed with a growing understanding of the disease pathophysiology. Paramount to the care of affected patients is the delivery of lung-protective mechanical ventilation which prioritizes tidal volume and plateau pressure limitation. Lung protection can probably be further enhanced by scaling target tidal volumes to the specific respiratory mechanics of individual patients. The best procedure for selecting optimal positive end-expiratory pressure (PEEP) in ARDS remains uncertain; several relevant issues must be considered when selecting PEEP, particularly lung recruitability. Noninvasive ventilation must be used with caution in ARDS as excessively high respiratory drive can further exacerbate lung injury; newer modes of delivery offer promising approaches in hypoxemic respiratory failure. Airway pressure release ventilation offers an alternative approach to maximize lung recruitment and oxygenation, but clinical trials have not demonstrated a survival benefit of this mode over conventional ventilation strategies. Rescue therapy with high-frequency oscillatory ventilation is an important option in refractory hypoxemia. Despite a disappointing lack of benefit (and possible harm) in patients with moderate or severe ARDS, possibly due to lung hyperdistention and right ventricular dysfunction, high-frequency oscillation may improve outcome in patients with very severe hypoxemia.

Exhaled air dispersion during high-flow nasal cannula therapy versus CPAP via different masks

BACKGROUND

High-flow nasal cannula (HFNC) is an emerging therapy for respiratory failure but the extent of exhaled air dispersion during treatment is unknown. We examined exhaled air dispersion during HFNC therapy versus continuous positive airway pressure (CPAP) on a human patient simulator (HPS) in an isolation room with 16 air changes·h^-1.

METHODS

The HPS was programmed to represent different severity of lung injury. CPAP was delivered at 5-20 cmH₂O via nasal pillows (Respironics Nuance Pro Gel or ResMed Swift FX) or an oronasal mask (ResMed Quattro Air). HFNC, humidified to 37°C, was delivered at 10-60 L·min^-1 to the HPS. Exhaled airflow was marked with intrapulmonary smoke for visualisation and revealed by laser light-sheet. Normalised exhaled air concentration was estimated from the light scattered by the smoke particles. Significant exposure was defined when there was ≥20% normalised smoke concentration.

RESULTS

In the normal lung condition, mean±sd exhaled air dispersion, along the sagittal plane, increased from 186±34 to 264±27 mm and from 207±11 to 332±34 mm when CPAP was increased from 5 to 20 cmH₂O via Respironics and ResMed nasal pillows, respectively. Leakage from the oronasal mask was negligible. Mean±sd exhaled air distances increased from 65±15 to 172±33 mm when HFNC was increased from 10 to 60 L·min^-1. Air leakage to 620 mm occurred laterally when HFNC and the interface tube became loose.

CONCLUSION

Exhaled air dispersion during HFNC and CPAP via different interfaces is limited provided there is good mask interface fitting.

Noninvasive ventilation in critically ill patients with the Middle East respiratory syndrome

Background

Noninvasive ventilation (NIV) has been used in patients with the Middle East respiratory syndrome (MERS) with acute hypoxemic respiratory failure, but the effectiveness of this approach has not been studied.

Methods

Patients with MERS from 14 Saudi Arabian centers were included in this analysis. Patients who were initially managed with NIV were compared to patients who were managed only with invasive mechanical ventilation (invasive MV).

Results

Of 302 MERS critically ill patients, NIV was used initially in 105 (35%) patients, whereas 197 (65%) patients were only managed with invasive MV. Patients who were managed with NIV initially had lower baseline SOFA score and less extensive infiltrates on chest radiograph compared with patients managed with invasive MV. The vast majority (92.4%) of patients who were managed initially with NIV required intubation and invasive mechanical ventilation, and were more likely to require inhaled nitric oxide compared to those who were managed initially with invasive MV. ICU and hospital length of stay were similar between NIV patients and invasive MV patients. The use of NIV was not independently associated with 90‐day mortality (propensity score‐adjusted odds ratio 0.61, 95% CI [0.23, 1.60] P = 0.27).

Conclusions

In patients with MERS and acute hypoxemic respiratory failure, NIV failure was very high. The use of NIV was not associated with improved outcomes.

Patient self-inflicted lung injury: implications for acute hypoxemic respiratory failure and ARDS patients on non-invasive support

The role of spontaneous breathing among patients with acute hypoxemic respiratory failure and ARDS is debated: while avoidance of intubation with noninvasive ventilation (NIV) or high-flow nasal cannula improves clinical outcome, treatment failure worsens mortality. Recent data suggest patient self-inflicted lung injury (P-SILI) as a possible mechanism aggravating lung damage in these patients. P-SILI is generated by intense inspiratory effort yielding: (A) swings in transpulmonary pressure (i.e. lung stress) causing the inflation of big volumes in an aerated compartment markedly reduced by the disease-induced aeration loss; (B) abnormal increases in transvascular pressure, favouring negative-pressure pulmonary edema; (C) an intra-tidal shift of gas between different lung zones, generated by different transmission of muscular force (i.e. pendelluft); (D) diaphragm injury. Experimental data suggest that not all subjects are exposed to the development of P-SILI: patients with a PaO2/FiO2 ratio below 200 mmHg may represent the most at risk population. For them, current evidence indicates that high-flow nasal cannula alone may be superior to intermittent sessions of low-PEEP NIV delivered through face mask, while continuous high-PEEP helmet NIV likely promotes treatment success and may mitigate lung injury. The optimal initial noninvasive treatment of hypoxemic respiratory failure/ARDS remains however uncertain; high-flow nasal cannula and high-PEEP helmet NIV are promising tools to enhance success of the approach, but the best balance between these techniques has yet to be identified. During noninvasive support, careful clinical monitoring remains mandatory for prompt detection of treatment failure, in order not to delay intubation and protective ventilation.

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.

Management of adverse events associated with idelalisib treatment in chronic lymphocytic leukemia and follicular lymphoma: A multidisciplinary position paper

The introduction of new therapeutic agents in chronic lymphocytic leukemia (CLL) and follicular lymphoma (FL), including the new kinase inhibitor idelalisib, has changed the therapeutic landscape of these diseases. However, the use of idelalisib is associated with a peculiar profile of side effects, which require an optimization of the current approach to prophylaxis and supportive treatment. Moving from the recognition that the abovementioned issue represents an unmet need in CLL and FL, a multidisciplinary panel of experts was convened to produce a consensus document aiming to provide practical recommendations for the management of the side effects during idelalisib therapy for CLL and FL. The present publication represents a consensus document from a series of meetings held during 2017. The Panel generated clinical key questions using the criterion of clinical relevance through a Delphi process and explored 4 domains, ie, diarrhea/colitis, transaminitis, pneumonitis, and infectious complications. Using the consensus method, the Panel was able to shape recommendations which may assist hematologist to minimize adverse events and guarantee adherence to treatment in patients with CLL and FL candidate to receive idelalisib.

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.

Risk factors and prognosis of acute respiratory distress syndrome following abdominal surgery

Risk factors and prognosis of acute respiratory distress syndrome (ARDS) following abdominal surgery were investigated. Five hundred and thirty-two patients who underwent abdominal surgery in Dongyang People's Hospital from February 2006 to May 2016 were enrolled. Among them, 113 patients had ARDS after surgery and 45 patients died. Those patients were included in observation group. The 419 patients who did not develop ARDS were included in control group, and 11 patients died. General data of patients were statistically analyzed, and the factors with statistical significance were subjected to multivariate logistic regression analysis to analyze the risk factors of ARDS. There was a significant difference in age, infection, trauma-to-surgery time, and prognosis between the two groups (P<0.05). Perioperative blood loss, blood transfusion volume, and fluid volume in the observation group were significantly higher than those in the control group (P<0.05). Heart rate, ratio of PaO2/FiO2, ratio of high (low) blood glucose, levels of procalcitonin (PCT) and albumin (ALB) were significantly different between the two groups. Heart rate, PCT, long-term health assessment (APACHE) II scores were higher in observation group than those in control group (P<0.05). Percentage of hyperglycemic patients, PaO2/FiO2, and ALB were lower in observation group than those in control group (P<0.05). Occurrence of ARDS after abdominal surgery was related to age, infection, heart rate, PaO2/FiO2, and PCT levels (P<0.05). Age, infection, heart rate, PaO2/FiO2, ALB and APACHE II scores were related to the prognosis of patients with ARDS after abdominal surgery (P<0.05). Age, infection, heart rate, PaO2/FiO2, PCT levels, blood loss, blood transfusion volume, and infusion volume may be risk factors for ARDS after abdominal surgery. Age, infection, heart rate, PaO2/FiO2, ALB, and APACHE II scores may be related to prognosis of patients with ARDS after abdominal surgery.

Sepsis associated acute kidney injury

Sepsis is defined as organ dysfunction resulting from the host's deleterious response to infection. One of the most common organs affected is the kidneys, resulting in sepsis associated acute kidney injury (SA-AKI) that contributes to the morbidity and mortality of sepsis. A growing body of knowledge has illuminated the clinical risk factors, pathobiology, response to treatment, and elements of renal recovery that have advanced our ability to prevent, detect, and treat SA-AKI. Despite these advances, SA-AKI remains an important concern and clinical burden, and further study is needed to reduce the acute and chronic consequences. This review summarizes the relevant evidence, with a focus on the risk factors, early recognition and diagnosis, treatment, and long term consequences of SA-AKI. In addition to literature pertaining to SA-AKI specifically, pertinent sepsis and acute kidney injury literature relevant to SA-AKI was included.

Acute respiratory distress syndrome

The acute respiratory distress syndrome (ARDS) is a common cause of respiratory failure in critically ill patients and is defined by the acute onset of noncardiogenic pulmonary oedema, hypoxaemia and the need for mechanical ventilation. ARDS occurs most often in the setting of pneumonia, sepsis, aspiration of gastric contents or severe trauma and is present in ~10% of all patients in intensive care units worldwide. Despite some improvements, mortality remains high at 30-40% in most studies. Pathological specimens from patients with ARDS frequently reveal diffuse alveolar damage, and laboratory studies have demonstrated both alveolar epithelial and lung endothelial injury, resulting in accumulation of protein-rich inflammatory oedematous fluid in the alveolar space. Diagnosis is based on consensus syndromic criteria, with modifications for under-resourced settings and in paediatric patients. Treatment focuses on lung-protective ventilation; no specific pharmacotherapies have been identified. Long-term outcomes of patients with ARDS are increasingly recognized as important research targets, as many patients survive ARDS only to have ongoing functional and/or psychological sequelae. Future directions include efforts to facilitate earlier recognition of ARDS, identifying responsive subsets of patients and ongoing efforts to understand fundamental mechanisms of lung injury to design specific treatments.

Sepsis and Pediatric Acute Respiratory Distress Syndrome

The epidemiology of the acute respiratory distress syndrome (ARDS) in pediatric sepsis is poorly defined. With significant data extrapolated from adult studies in sepsis and ARDS, sometimes with uncertain applicability, better pediatric-specific guidelines and dedicated investigations are warranted. The recent publication of a consensus definition for pediatric ARDS (PARDS) is the first step in addressing this knowledge gap. The aim of this review is to frame our current understanding of PARDS as it relates to pediatric sepsis, encompassing epidemiology, pathophysiology, and management. We argue that addressing the role of PARDS in pediatric sepsis requires significant attention to details with respect to how PARDS and sepsis are defined to accurately describe their epidemiology, natural history, and outcomes. Finally, we highlight certain aspects of PARDS management as they relate to the septic child and offer suggestion for future directions in this field.

The acute respiratory distress syndrome: pathophysiology, current clinical practice, and emerging therapies

INTRODUCTION

More than fifty years after the first description of acute respiratory distress syndrome (ARDS) by Ashbaugh and colleagues, no specific treatment of the underlying pathophysiological processes is available. The current therapeutic regime is comprised of supportive measures such as lung protective ventilation, restrictive fluid management, paralyzing drugs, and prone positioning. Although vast improvements have been made in ARDS-treatment during the last five decades, mortality among patients with severe ARDS remains at an unacceptable rate of 45%. Areas covered: This article reviews the evolution of the currently used definition, established pathophysiological mechanism, highlights the current best clinical practice to treat ARDS, gives a brief outlook on cutting edge trends in ARDS research and closes with an expert opinion on the subject. Expert commentary: Individualizing the provided measures to specific genotypes is the key challenge in ARDS research today. The ongoing digital revolution will help to individualize ARDS-treatment and will therefore presumably improve survival and quality of life.

Biomedical engineer's guide to the clinical aspects of intensive care mechanical ventilation

Background

Mechanical ventilation is an essential therapy to support critically ill respiratory failure patients. Current standards of care consist of generalised approaches, such as the use of positive end expiratory pressure to inspired oxygen fraction (PEEP–FiO₂) tables, which fail to account for the inter- and intra-patient variability between and within patients. The benefits of higher or lower tidal volume, PEEP, and other settings are highly debated and no consensus has been reached. Moreover, clinicians implicitly account for patient-specific factors such as disease condition and progression as they manually titrate ventilator settings. Hence, care is highly variable and potentially often non-optimal. These conditions create a situation that could benefit greatly from an engineered approach. The overall goal is a review of ventilation that is accessible to both clinicians and engineers, to bridge the divide between the two fields and enable collaboration to improve patient care and outcomes. This review does not take the form of a typical systematic review. Instead, it defines the standard terminology and introduces key clinical and biomedical measurements before introducing the key clinical studies and their influence in clinical practice which in turn flows into the needs and requirements around how biomedical engineering research can play a role in improving care. Given the significant clinical research to date and its impact on this complex area of care, this review thus provides a tutorial introduction around the review of the state of the art relevant to a biomedical engineering perspective.

Discussion

This review presents the significant clinical aspects and variables of ventilation management, the potential risks associated with suboptimal ventilation management, and a review of the major recent attempts to improve ventilation in the context of these variables. The unique aspect of this review is a focus on these key elements relevant to engineering new approaches. In particular, the need for ventilation strategies which consider, and directly account for, the significant differences in patient condition, disease etiology, and progression within patients is demonstrated with the subsequent requirement for optimal ventilation strategies to titrate for patient- and time-specific conditions.

Conclusion

Engineered, protective lung strategies that can directly account for and manage inter- and intra-patient variability thus offer great potential to improve both individual care, as well as cohort clinical outcomes.

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

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

High-flow nasal therapy vs standard oxygen during breaks off noninvasive ventilation for acute respiratory failure: A pilot randomized controlled trial

PURPOSE

To assess the role of high-flow nasal therapy (HFNT) compared to standard oxygen (SO) as complementary therapy to non-invasive ventilation (NIV).

METHODS

Multicenter trial including patients (n = 54) anticipated to receive NIV for ≥24 h due to acute or acute-on-chronic respiratory failure. Subjects were randomized (1:1) to SO or HFNT during breaks off NIV. Primary outcome was total time on and off NIV. Secondary outcomes were comfort and dyspnea, respiratory rate (RR), oxygen saturation (S_pO₂), tolerance and side effects.

RESULTS

Total time per patient on NIV (1315 vs 1441 min) and breaks (1362 vs 1196 min), and mean duration of each break (520 vs 370 min) were similar in the HFNT and SO arms (p > .05). Comfort score was higher on HFNT than on SO (8.3 ± 2.7 vs 6.9 ± 2.3, p = .001). Dyspnea, RR and S_pO₂ were similar in the two arms, but the increase in RR and dyspnea seen with SO during breaks did not occur with HFNT.

CONCLUSION

Compared to SO, HFNT did not reduce time on NIV. However, it was more comfortable and the increase in RR and dyspnea seen with SO did not occur with HFNT. Therefore, HFNT could be a suitable alternative to SO during breaks off NIV.

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

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Clinical characteristics and outcomes associated with nasal intermittent mandatory ventilation in acute pediatric respiratory failure

AIM

To characterize the clinical course and outcomes of nasal intermittent mandatory ventilation (NIMV) use in acute pediatric respiratory failure.

METHODS

We identified all patients treated with NIMV in the pediatric intensive care unit (PICU) or inpatient general pediatrics between January 2013 and December 2015 at two academic centers. Patients who utilized NIMV with other modes of noninvasive ventilation during the same admission were included. Data included demographics, vital signs on admission and prior to initiation of NIMV, pediatric risk of mortality III (PRISM-III) scores, complications, respiratory support characteristics, PICU and hospital length of stays, duration of respiratory support, and complications. Patients who did not require escalation to mechanical ventilation were defined as NIMV responders; those who required escalation to mechanical ventilation (MV) were defined as NIMV non-responders. NIMV responders were compared to NIMV non-responders.

RESULTS

Forty-two patients met study criteria. Six (14%) failed treatment and required MV. The majority of the patients (74%) had a primary diagnosis of bronchiolitis. The median age of these 42 patients was 4 mo (range 0.5-28.1 mo, IQR 7, P = 0.69). No significant difference was measured in other baseline demographics and vitals on initiation of NIMV; these included age, temperature, respiratory rate, O2 saturation, heart rate, systolic blood pressure, diastolic blood pressure, and PRISM-III scores. The duration of NIMV was shorter in the NIMV non-responder vs NIMV responder group (6.5 h vs 65 h, P < 0.0005). Otherwise, NIMV failure was not associated with significant differences in PICU length of stay (LOS), hospital LOS, or total duration of respiratory support. No patients had aspiration pneumonia, pneumothorax, or skin breakdown.

CONCLUSION

Most of our patients responded to NIMV. NIMV failure is not associated with differences in hospital LOS, PICU LOS, or duration of respiratory support.

Recent advances in understanding and treating acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is a clinically and biologically heterogeneous disorder associated with many disease processes that injure the lung, culminating in increased non-hydrostatic extravascular lung water, reduced compliance, and severe hypoxemia. Despite enhanced understanding of molecular mechanisms, advances in ventilatory strategies, and general care of the critically ill patient, mortality remains unacceptably high. The Berlin definition of ARDS has now replaced the American-European Consensus Conference definition. The recently concluded Large Observational Study to Understand the Global Impact of Severe Acute Respiratory Failure (LUNG-SAFE) provided worldwide epidemiological data of ARDS including prevalence, geographic variability, mortality, and patterns of mechanical ventilation use. Failure of clinical therapeutic trials prompted the investigation and subsequent discovery of two distinct phenotypes of ARDS (hyper-inflammatory and hypo-inflammatory) that have different biomarker profiles and clinical courses and respond differently to the random application of positive end expiratory pressure (PEEP) and fluid management strategies. Low tidal volume ventilation remains the predominant mainstay of the ventilatory strategy in ARDS. High-frequency oscillatory ventilation, application of recruitment maneuvers, higher PEEP, extracorporeal membrane oxygenation, and alternate modes of mechanical ventilation have failed to show benefit. Similarly, most pharmacological therapies including keratinocyte growth factor, beta-2 agonists, and aspirin did not improve outcomes. Prone positioning and early neuromuscular blockade have demonstrated mortality benefit, and clinical guidelines now recommend their use. Current ongoing trials include the use of mesenchymal stem cells, vitamin C, re-evaluation of neuromuscular blockade, and extracorporeal carbon dioxide removal. In this article, we describe advances in the diagnosis, epidemiology, and treatment of ARDS over the past decade.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Recurrence plots for the assessment of patient-ventilator interactions quality during invasive mechanical ventilation

Inappropriate patient-ventilator interactions' (PVI) quality is associated with adverse clinical consequences, such as patient anxiety/fear and increased need of sedative and paralytic agents. Thus, technological devices/tools to support the recognition and monitoring of different PVI quality are of great interest. In the present study, we investigate two tools based on a recent landmark study which applied recurrence plots (RPs) and recurrence quantification analysis (RQA) techniques in non-invasive mechanical ventilation. Our interest is in how this approach could be a daily part of critical care professionals' routine (which are not familiar with dynamical systems theory methods and concepts). Two representative time series of three typical PVI "scenarios" were selected from 6 critically ill patients subjected to invasive mechanical ventilation. First, both the (i) main signatures in RPs and the (ii) respective signals that provide the most (visually) discriminant RPs were identified. This allows one to propose a visual identification protocol for PVIs' quality through the RPs' overall aspect. Support for the effectiveness of this visual based assessment tool is given by a RQA-based assessment tool. A statistical analysis shows that both the recurrence rate and the Shannon entropy are able to identify the selected PVI scenarios. It is then expected that the development of an objective method can reliably identify PVI quality, where the results corroborate the potential of RPs/RQA in the field of respiratory pattern analysis.

Immunocompromised patients with acute respiratory distress syndrome: secondary analysis of the LUNG SAFE database

Background

The aim of this study was to describe data on epidemiology, ventilatory management, and outcome of acute respiratory distress syndrome (ARDS) in immunocompromised patients.

Methods

We performed a post hoc analysis on the cohort of immunocompromised patients enrolled in the Large Observational Study to Understand the Global Impact of Severe Acute Respiratory Failure (LUNG SAFE) study. The LUNG SAFE study was an international, prospective study including hypoxemic patients in 459 ICUs from 50 countries across 5 continents.

Results

Of 2813 patients with ARDS, 584 (20.8%) were immunocompromised, 38.9% of whom had an unspecified cause. Pneumonia, nonpulmonary sepsis, and noncardiogenic shock were their most common risk factors for ARDS. Hospital mortality was higher in immunocompromised than in immunocompetent patients (52.4% vs 36.2%; p < 0.0001), despite similar severity of ARDS. Decisions regarding limiting life-sustaining measures were significantly more frequent in immunocompromised patients (27.1% vs 18.6%; p < 0.0001). Use of noninvasive ventilation (NIV) as first-line treatment was higher in immunocompromised patients (20.9% vs 15.9%; p = 0.0048), and immunodeficiency remained independently associated with the use of NIV after adjustment for confounders. Forty-eight percent of the patients treated with NIV were intubated, and their mortality was not different from that of the patients invasively ventilated ab initio.

Conclusions

Immunosuppression is frequent in patients with ARDS, and infections are the main risk factors for ARDS in these immunocompromised patients. Their management differs from that of immunocompetent patients, particularly the greater use of NIV as first-line ventilation strategy. Compared with immunocompetent subjects, they have higher mortality regardless of ARDS severity as well as a higher frequency of limitation of life-sustaining measures. Nonetheless, nearly half of these patients survive to hospital discharge.

Trial registration

ClinicalTrials.gov, NCT02010073. Registered on 12 December 2013.

Electronic supplementary material

The online version of this article (10.1186/s13054-018-2079-9) contains supplementary material, which is available to authorized users.

Acute Respiratory Distress Syndrome: Advances in Diagnosis and Treatment

IMPORTANCE

Acute respiratory distress syndrome (ARDS) is a life-threatening form of respiratory failure that affects approximately 200 000 patients each year in the United States, resulting in nearly 75 000 deaths annually. Globally, ARDS accounts for 10% of intensive care unit admissions, representing more than 3 million patients with ARDS annually.

OBJECTIVE

To review advances in diagnosis and treatment of ARDS over the last 5 years.

EVIDENCE REVIEW

We searched MEDLINE, EMBASE, and the Cochrane Database of Systematic Reviews from 2012 to 2017 focusing on randomized clinical trials, meta-analyses, systematic reviews, and clinical practice guidelines. Articles were identified for full text review with manual review of bibliographies generating additional references.

FINDINGS

After screening 1662 citations, 31 articles detailing major advances in the diagnosis or treatment of ARDS were selected. The Berlin definition proposed 3 categories of ARDS based on the severity of hypoxemia: mild (200 mm Hg<Pao2/Fio2≤300 mm Hg), moderate (100 mm Hg<Pao2/Fio2≤200 mm Hg), and severe (Pao2/Fio2 ≤100 mm Hg), along with explicit criteria related to timing of the syndrome's onset, origin of edema, and the chest radiograph findings. The Berlin definition has significantly greater predictive validity for mortality than the prior American-European Consensus Conference definition. Clinician interpretation of the origin of edema and chest radiograph criteria may be less reliable in making a diagnosis of ARDS. The cornerstone of management remains mechanical ventilation, with a goal to minimize ventilator-induced lung injury (VILI). Aspirin was not effective in preventing ARDS in patients at high-risk for the syndrome. Adjunctive interventions to further minimize VILI, such as prone positioning in patients with a Pao2/Fio2 ratio less than 150 mm Hg, were associated with a significant mortality benefit whereas others (eg, extracorporeal carbon dioxide removal) remain experimental. Pharmacologic therapies such as β2 agonists, statins, and keratinocyte growth factor, which targeted pathophysiologic alterations in ARDS, were not beneficial and demonstrated possible harm. Recent guidelines on mechanical ventilation in ARDS provide evidence-based recommendations related to 6 interventions, including low tidal volume and inspiratory pressure ventilation, prone positioning, high-frequency oscillatory ventilation, higher vs lower positive end-expiratory pressure, lung recruitment maneuvers, and extracorporeal membrane oxygenation.

CONCLUSIONS AND RELEVANCE

The Berlin definition of acute respiratory distress syndrome addressed limitations of the American-European Consensus Conference definition, but poor reliability of some criteria may contribute to underrecognition by clinicians. No pharmacologic treatments aimed at the underlying pathology have been shown to be effective, and management remains supportive with lung-protective mechanical ventilation. Guidelines on mechanical ventilation in patients with acute respiratory distress syndrome can assist clinicians in delivering evidence-based interventions that may lead to improved outcomes.

Cost Analysis of Noninvasive Helmet Ventilation Compared with Use of Noninvasive Face Mask in ARDS

Intensive care unit (ICU) costs have doubled since 2000, totalling 108 billion dollars per year. Acute respiratory distress syndrome (ARDS) has a prevalence of 10.4% and a 28-day mortality of 34.8%. Noninvasive ventilation (NIV) is used in up to 30% of cases. A recent randomized controlled trial by Patel et al. (2016) showed lower intubation rates and 90-day mortality when comparing helmet to face mask NIV in ARDS. The population in the Patel et al. trial was used for cost analysis in this study. Projections of cost savings showed a decrease in ICU costs by $2527 and hospital costs by $3103 per patient, along with a 43.3% absolute reduction in intubation rates. Sensitivity analysis showed consistent cost reductions. Projected annual cost savings, assuming the current prevalence of ARDS, were $237538 in ICU costs and $291682 in hospital costs. At a national level, using yearly incidence of ARDS cases in American ICUs, this represents $449 million in savings. Helmet NIV, compared to face mask NIV, in nonintubated patients with ARDS, reduces ICU and hospital direct-variable costs along with intubation rates, LOS, and mortality. A large-scale cost-effectiveness analysis is needed to validate the findings.

Positive end expiratory pressure in acute hypoxemic respiratory failure due to community acquired pneumonia: do we need a personalized approach?

Background

Acute respiratory failure (ARF) is a life-threatening complication in patients with community acquired pneumonia (CAP). The use of non-invasive ventilation is controversial. With this prospective, observational study we aimed to describe a protocol to assess whether a patient with moderate-to-severe hypoxemic ARF secondary to CAP benefits, in clinical and laboratoristic terms, from the application of a positive end expiratory pressure (PEEP) + oxygen vs oxygen alone.

Methods

Patients who benefit from PEEP application (PEEP-responders) were defined as those with partial pressure of arterial oxygen to the fraction of inspired oxygen (PaO2/FiO2) increase >20% and/or reduction of respiratory distress during PEEP + oxygen therapy compared to oxygen therapy alone. Clinical characteristics and outcomes were compared between PEEP-responders and PEEP-non responders.

Results

Out of 41 patients, 27 (66%) benefit from PEEP application (PEEP-responders), the best response was obtained with a PEEP of 10 cmH2O in 13 patients, 7.5 cmH2O in eight and 5 cmH2O in six. PEEP-responders were less likely to present comorbidities compared to PEEP-non responders. No differences between groups were found in regards to endotracheal intubation criteria fullfillment, intensive care unit admission and in-hospital mortality, while PEEP-responders had a shorter length of hospital stay.

Discussion

The application of a protocol to evaluate PEEP responsiveness might be useful in patients with moderate-to-severe hypoxemic ARF due to CAP in order to personalize and maximize the effectiveness of therapy, and prevent the inappropriate PEEP use. PEEP responsiveness does not seem to be associated with better outcomes, with the exception of a shorter length of hospital stay.

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.

ARDS: challenges in patient care and frontiers in research

This review discusses the clinical challenges associated with ventilatory support and pharmacological interventions in patients with acute respiratory distress syndrome (ARDS). In addition, it discusses current scientific challenges facing researchers when planning and performing trials of ventilatory support or pharmacological interventions in these patients.

Noninvasive mechanical ventilation is used in some patients with ARDS. When intubated and mechanically ventilated, ARDS patients should be ventilated with low tidal volumes. A plateau pressure <30 cmH₂O is recommended in all patients. It is suggested that a plateau pressure <15 cmH₂O should be considered safe. Patient with moderate and severe ARDS should receive higher levels of positive end-expiratory pressure (PEEP). Rescue therapies include prone position and neuromuscular blocking agents. Extracorporeal support for decapneisation and oxygenation should only be considered when lung-protective ventilation is no longer possible, or in cases of refractory hypoxaemia, respectively. Tracheotomy is only recommended when prolonged mechanical ventilation is expected.

Of all tested pharmacological interventions for ARDS, only treatment with steroids is considered to have benefit.

Proper identification of phenotypes, known to respond differently to specific interventions, is increasingly considered important for clinical trials of interventions for ARDS. Such phenotypes could be defined based on clinical parameters, such as the arterial oxygen tension/inspiratory oxygen fraction ratio, but biological marker profiles could be more promising.

Treatment of ARDS is mainly through the prevention of ventilation-induced lung injuryhttp://ow.ly/DeJC30hGWfi