Non-invasive ventilation in acute exacerbations of chronic obstructive pulmonary disease: long term survival and predictors of in-hospital outcome

A randomised controlled trial of non-invasive ventilation compared with extracorporeal carbon dioxide removal for acute hypercapnic exacerbations of chronic obstructive pulmonary disease

Background

Patients presenting with acute hypercapnic respiratory failure due to exacerbations of chronic obstructive pulmonary disease (AECOPD) are typically managed with non-invasive ventilation (NIV). The impact of low-flow extracorporeal carbon dioxide removal (ECCO₂R) on outcome in these patients has not been explored in randomised trials.

Methods

Open-label randomised trial comparing NIV (NIV arm) with ECCO₂R (ECCO₂R arm) in patients with AECOPD at high risk of NIV failure (pH < 7.30 after ≥ 1 h of NIV). The primary endpoint was time to cessation of NIV. Secondary outcomes included device tolerance and complications, changes in arterial blood gases, hospital survival.

Results

Eighteen patients (median age 67.5, IQR (61.5–71) years; median GOLD stage 3 were enrolled (nine in each arm). Time to NIV discontinuation was shorter with ECCO₂R (7:00 (6:18–8:30) vs 24:30 (18:15–49:45) h, p = 0.004). Arterial pH was higher with ECCO₂R at 4 h post-randomisation (7.35 (7.31–7.37) vs 7.25 (7.21–7.26), p < 0.001). Partial pressure of arterial CO₂ (PaCO₂) was significantly lower with ECCO₂R at 4 h (6.8 (6.2–7.15) vs 8.3 (7.74–9.3) kPa; p = 0.024). Dyspnoea and comfort both rapidly improved with commencement of ECCO₂R. There were no severe or life-threatening complications in the study population. There were no episodes of major bleeding or red blood cell transfusion in either group. ICU and hospital length of stay were longer with ECCO₂R, and there was no difference in 90-day mortality or functional outcomes at follow-up.

Interpretation

There is evidence of benefit associated with ECCO₂R with time to improvement in respiratory acidosis, in respiratory physiology and an immediate improvement in patient comfort and dyspnoea with commencement of ECCO₂R. In addition, there was minimal clinically significant adverse events associated with ECCO₂R use in patients with AECOPD at risk of failing or not tolerating NIV. However, the ICU and hospital lengths of stay were longer in the ECCO₂R for similar outcomes.

Trial registration The trial is prospectively registered on ClinicalTrials.gov: NCT02086084. Registered on 13th March 2014, https://clinicaltrials.gov/ct2/show/NCT02086084?cond=ecco2r&draw=2&rank=8

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-022-01006-8.

Nasal high-flow compared to non-invasive ventilation in treatment of acute acidotic hypercapnic exacerbation of chronic obstructive pulmonary disease-protocol for a randomized controlled noninferiority trial (ELVIS)

Background

Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) have a major negative impact on health status, rates of hospitalization, readmission, disease progression and mortality. Non-invasive ventilation (NIV) is the standard therapy for hypercapnic acidotic respiratory failure in AECOPD. Despite its beneficial effects, NIV is often poorly tolerated (11–34 % failure rate). An increasing number of studies have documented a beneficial effect of nasal high-flow (NHF) in acute hypercapnia. We designed a prospective, randomized, multi-centre, open label, non-inferiority trial to compare treatment failure in nasal NHF vs NIV in patients with acidotic hypercapnic AECOPD.

Methods

The study will be conducted in about 35 sites in Germany. Patients with hypercapnic AECOPD with respiratory acidosis (pH < 7.35) will be randomized 1:1 to NIV or NHF. The primary outcome is the combined endpoint of intubation, treatment failure or death at 72 h. The switch from one to the other device marks a device failure but acts as a rescue treatment in absence of intubation criteria. A sample size of 720 was calculated to have 80% power for showing that NHF is non-inferior to NIV with a margin of 8 percentage points. Linear regression will be used for the confirmatory analysis.

Discussion

If NHF is shown to be non-inferior to NIV in acidotic hypercapnic AECOPD, it could become an important alternative treatment.

Trial registration

ClinicalTrials.gov, NCT04881409, Registered on May 11, 2021

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05978-z.

Inspiratory muscle responses to sudden airway occlusion in chronic obstructive pulmonary disease

Brief airway occlusion produces a potent reflex inhibition of inspiratory muscles that is thought to protect against aspiration. Its duration is prolonged in asthma and obstructive sleep apnea. We assessed this inhibitory reflex (IR) in chronic obstructive pulmonary disease (COPD). Reflex responses to brief (250 ms) inspiratory occlusions were measured in 18 participants with moderate to severe COPD (age 73 ± 11 yr) and 17 healthy age-matched controls (age 72 ± 6 yr). We compared the incidence and properties of the IR between groups. Median eupneic preocclusion electromyographic activity was higher in the COPD group than controls (9.4 μV vs. 5.2 μV, P = 0.001). Incidence of the short-latency IR was higher in the COPD group compared with controls (15 participants vs. 7 participants, P = 0.010). IR duration for scalenes was similar for the COPD and control groups [73 ± 37 ms (means ± SD) and 90 ± 50 ms, respectively] as was the magnitude of inhibition. IRs in the diaphragm were not detected in the controls but were present in 9 participants of the COPD group (P = 0.001). The higher incidence of the IR in the COPD group than in the age-matched controls may reflect the increased inspiratory neural drive in the COPD group. This higher drive counteracts changes in chest wall and lung mechanics. However, when present, the reflex was similar in size and duration in the two groups. The relation between the IR in COPD and swallowing function could be assessed.NEW & NOTEWORTHY A potent short-latency reflex inhibition of inspiratory muscles produced by airway occlusion was tested in people with COPD and age-matched controls. The reflex was more prevalent in COPD, presumably due to an increased neural drive to breathe. When present, the reflex was similar in duration in the two groups, longer than historical data for younger control groups. The work reveals novel differences in reflex control of inspiratory muscles due to aging as well as COPD.

High-Flow Oxygen Therapy Application in Chronic Obstructive Pulmonary Disease Patients With Acute Hypercapnic Respiratory Failure: A Multicenter Study

Objectives

To evaluate the effect of high-flow oxygen implementation on the respiratory rate as a first-line ventilation support in chronic obstructive pulmonary disease patients with acute hypercapnic respiratory failure.

Design

Multicenter, prospective, analytic observational case series study.

Setting

Five ICUs in Argentina, between August 2018 and September 2019.

Patients

Patients greater than or equal to 18 years old with moderate to very severe chronic obstructive pulmonary disease, who had been admitted to the ICU with a diagnosis of hypercapnic acute respiratory failure, were entered in the study.

Interventions

High-flow oxygen therapy through nasal cannula delivered using high-velocity nasal insufflation.

Measurements and Main Results

Forty patients were studied, 62.5% severe chronic obstructive pulmonary disease. After the first hour of high-flow nasal cannula implementation, there was a significant decrease of respiratory rate compared with baseline values, with a 27% decline (29 vs 21 breaths/min; p < 0.001). Furthermore, a significant reduction of Paco₂ (57 vs 52 mm Hg [7.6 vs 6.9 kPa]; p < 0.001) was observed. The high-flow nasal cannula application failed in 18% patients. In this group, the respiratory rate, pH, and Paco₂ showed no significant change during the first hour in these patients.

Conclusions

High-flow oxygen therapy through nasal cannula delivered using high-velocity nasal insufflation was an effective tool for reducing respiratory rate in these chronic obstructive pulmonary disease patients with acute hypercapnic respiratory failure. Early determination and subsequent monitoring of clinical and blood gas parameters may help predict the outcome.

Predictors for long-term mortality in COPD patients requiring non-invasive positive pressure ventilation for the treatment of acute respiratory failure

INTRODUCTION

The effectiveness of non-invasive mechanical ventilation (NIV) in the management of COPD patients suffering from acute respiratory failure (ARF) as a consequence of exacerbation of the disease, is well established. However, data on long-term outcomes and their predictors, including the individual response to NIV, are scarce.

OBJECTIVES

To investigate predictors for short- and long-term mortality in this study population.

METHODS

A retrospective cohort study was performed including all patients admitted to the Medium Respiratory Care Unit of Maastricht University Medical Center in Maastricht, the Netherlands, with hospitalized exacerbation of COPD (H-ECOPD) with ARF requiring NIV for the first time between January 2009 and December 2011. An extensive number of potential predictors of outcomes, including the response to NIV, were determined on admission and during hospitalization. Univariate and multivariate logistic regression was used for statistical analysis.

RESULTS

Seventy-eight consecutive patients with moderate to severe COPD (mean age 71.0 ± 10.7 years; 48.7% males) were included; In-hospital, 1-year and 2-year mortality rates were 14.1%, 43.6% and 56.4%, respectively. Independent risk factors for 2-year mortality were: advanced age (odds ratio(OR) 1.025; confidence interval (CI) 1.002-1.049; P = 0.037), prolonged NIV use more than 8 days (OR:1.054;CI:1.006-1.104; P = 0.027) and no successful response to NIV (OR:2.392;CI:1.297-4.413; P = 0.005).

CONCLUSION

Patients with an H-ECOPD requiring NIV for the first time, constitute a severely ill patient group with high in-hospital and 2-year mortality. This study identified advanced age, NIV use more than 8 days and unsuccessful response to NIV as clinical important independent predictors for long-term mortality.

Nasal high-flow oxygen versus noninvasive ventilation in acute exacerbation of COPD: protocol for a randomised noninferiority clinical trial

Background

Noninvasive ventilation (NIV) is considered as the first-line treatment for acute exacerbation of COPD (AECOPD) complicated by respiratory acidosis. Recent studies demonstrate a role of nasal high-flow oxygen (NHF) in AECOPD as an alternative treatment in patients intolerant to NIV or with contraindications to it.

Aim

The study aimed to evaluate whether NHF respiratory support is noninferior compared to NIV in respect to treatment failure, defined as need for intubation or change to alternative treatment group, in patients with AECOPD and mild-to-moderate acute or acute-on-chronic hypercapnic respiratory failure.

Methods

We designed a multicentre, prospective, randomised trial on patients with AECOPD, who have pH<7.35 but >7.25 and P_aCO2 >45 mmHg, in whom NIV is indicated as a first-line treatment. According to power analysis, 498 participants will be required for establishing noninferiority of NHF compared to NIV. Patients will be randomly assigned to receive NIV or NHF. Treatment will be adjusted to maintain S_pO2 between 88%–92% for both groups. Arterial blood gases, respiratory variables, comfort, dyspnoea score and any pulmonary or extrapulmonary complications will be assessed at baseline, before treatment initiation, and at 1, 2, 4, 6, 12, 24, 48 h, then once daily from day 3 to patient discharge, intubation or death.

Conclusion

Given the increasing number of studies demonstrating the physiological effects of NHF in COPD patients, we hypothesise that NHF respiratory support will be noninferior to NIV in patients with AECOPD and mild-to-moderate acute or acute on chronic hypercapnic respiratory failure.

Nasal high-flow oxygen could be an effective alternative to NIV respiratory support for patients with mild-to-moderate #AECOPD, especially for those who do not tolerate or have contraindications for NIVhttps://bit.ly/3bgxDYx

Predictors of NIV Treatment in Patients with COPD Exacerbation Complicated by Respiratory Acidaemia

Non-invasive ventilation (NIV) treatment decisions are poorly understood for patients with COPD exacerbation complicated by acute hypercapnic respiratory failure and respiratory acidaemia (ECOPD-RA). We identified 420 NIV-eligible patients from the DECAF study cohorts admitted with an ECOPD-RA. Using bivariate and multivariate analyses, we examined which indices were associated with clinicians' decisions to start NIV, including whether the presence of pneumonia was a deterrent. Admitting hospital, admission from institutional care, partial pressure of oxygen, cerebrovascular disease, pH, systolic blood pressure and white cell count were all associated with the provision of NIV. Of these indices, only pH was also a predictor of inpatient death. Those not treated with NIV included those with milder acidaemia and higher (and sometimes excessive) oxygen levels, and a frailer population with higher Extended Medical Research Council Dyspnoea scores, presumably deemed not suitable for NIV. Pneumonia was not associated with NIV treatment; 34 of 111 (30.6%) NIV-untreated patients had pneumonia, whilst 107 of 309 (34.6%) NIV-treated patients had pneumonia (p = 0.483). In our study, one in four NIV-eligible patients were not treated with NIV. Clinicians' NIV treatment decisions are not based on those indices most strongly associated with mortality risk. One of the strongest predictors of whether a patient received a life-saving treatment is which hospital they attended. Further research is required to aid in the risk stratification of this patient group which may help standardise and improve care.

Oxygen therapy in the pre-hospital setting for acute exacerbations of chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a global leading cause of morbidity and mortality, characterised by acute deterioration in symptoms. During these exacerbations, people are prone to developing alveolar hypoventilation, which may be partly caused by the administration of high inspired oxygen concentrations.

OBJECTIVES

To determine the effect of different inspired oxygen concentrations ("high flow" compared to "controlled") in the pre-hospital setting (prior to casualty/emergency department) on outcomes for people with acute exacerbations of COPD (AECOPD).

SEARCH METHODS

The Cochrane Airways Group Specialised Register, reference lists of articles and online clinical trial databases were searched. Authors of identified randomised controlled trials (RCTs) were also contacted for details of other relevant published and unpublished studies. The most recent search was conducted on 16 September 2019.

SELECTION CRITERIA

We included RCTs comparing oxygen therapy at different concentrations or oxygen therapy versus placebo in the pre-hospital setting for treatment of AECOPD.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. The primary outcome was all-cause and respiratory-related mortality.

MAIN RESULTS

The search identified a total of 824 citations; one study was identified for inclusion and two studies are awaiting classification. The 214 participants involved in the included study were adults with AECOPD, receiving treatment by paramedics en route to hospital. The mean age of participants was 68 years. A reduction in pre/in-hospital mortality was observed in favour of the titrated oxygen group (two deaths in the titrated oxygen group compared to 11 deaths in the high-flow control arm; risk ratio (RR) 0.22, 95% confidence interval (CI) 0.05 to 0.97; 214 participants). This translates to an absolute effect of 94 per 1000 (high-flow oxygen) compared to 21 per 1000 (titrated oxygen), and a number needed to treat for an additional beneficial outcome (NNTB) of 14 (95% CI 12 to 355) with titrated oxygen therapy. Other than mortality, no other adverse events were reported in the included study. Wide confidence intervals were observed between groups for arterial blood gas (though this may be confounded by protocol infidelity in the included study for this outcome measure), treatment failure requiring invasive or non-invasive ventilation or hospital utilisation. No data were reported for quality of life, lung function or dyspnoea. Risk of bias within the included study was largely unclear, though there was high risk of bias in domains relating to performance and attrition bias. We judged the evidence to be of low certainty, according to GRADE criteria.

AUTHORS' CONCLUSIONS

The one included study found a reduction in pre/in-hospital mortality for the titrated oxygen arm compared to the high-flow control arm. However, the paucity of evidence somewhat limits the reliability of these findings and generalisability to other settings. There is a need for robust, well-designed RCTs to further investigate the effect of oxygen therapies in the pre-hospital setting for people with AECOPD.

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.

Acute non-invasive ventilation - getting it right on the acute medical take

Non-invasive ventilation (NIV) given to the right patient, in the right setting, in the right way and at the right time improves outcomes. However, national audits reveal poor practice in patient selection, clinical judgement, treatment initiation and availability of trained staff. NIV is indicated for persistent acute hypercapnic respiratory failure (AHRF) with acidosis after usual medical management in chronic obstructive pulmonary disease (COPD) exacerbation and even without acidosis in neuromuscular disorders or other restrictive conditions eg obesity hypoventilation or kyphoscoliosis. Having trained staff in a suitable environment with adequate equipment are keys to its success, along with close monitoring. A plan should be put in place at the time of initiating NIV about the ceiling of care, eg escalation to intubation or palliation, if the patient is not improving with NIV. Early NIV failure is most likely due to technical issues, such as inadequate pressures or mask leak, while late failure is usually the consequence of advanced disease. Any presentation with AHRF is a poor prognostic indicator and outpatient respiratory follow-up is indicated following discharge. For selected patients with COPD who remain hypercapnic 2 weeks after an exacerbation, domiciliary NIV can reduce admissions and improve survival. For patients with neuromuscular disorders or kyphoscoliosis a presentation with AHRF almost always indicates the need for domiciliary NIV.

Noninvasive ventilation in acute hypoxic respiratory failure in medical intensive care unit: A study in rural medical college

Introduction:

Noninvasive ventilation (NIV) has emerged as an important tool for the management of acute hypoxic respiratory failure (AHRF) and has been the area of research in the last two decades. In this study, we have tried to find out the outcome of NIV in patients with AHRF.

Materials and Methods:

In this prospective, observational study, all the patients of AHRF requiring NIV were enrolled, and heart rate (HR), respiratory rate (RR), arterial blood gas parameters, and NIV settings at baseline, 1 h, and 4 h were collected. The patients were classified as AHRF with acute respiratory distress syndrome (ARDS) and AHRF without ARDS, which were further classified according to the outcome.

Results:

Among 200 patients admitted in medical intensive care unit (ICU), 50 patients (27 with ARDS and 23 without ARDS) were put on NIV. There was a significant improvement in HR, RR, PaO ₂, and inspiratory positive airway pressure after 1 and 4 h and significant improvement at 4 h in expiratory positive airway pressure in all the groups on NIV. Length of ICU stay and hospital stay was less in the nonintubated group. Mortality rate was 25.92% in the intubated group, while it was nil in the nonintubated group.

Conclusion:

NIV found to reduce the endotracheal intubation and mortality, by improving the outcome of the patient.

High-intensity versus low-intensity noninvasive positive pressure ventilation in patients with acute exacerbation of chronic obstructive pulmonary disease (HAPPEN): study protocol for a multicenter randomized controlled trial

BACKGROUND

Despite the positive outcomes of the use of noninvasive positive pressure ventilation (NPPV) in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD), NPPV fails in approximately 15% of patients with AECOPD, possibly because the inspiratory pressure delivered by conventional low-intensity NPPV is insufficient to improve ventilatory status for these patients. High-intensity NPPV, a novel form that delivers high inspiratory pressure, is believed to more efficiently augment alveolar ventilation than low-intensity NPPV, and it has been shown to improve ventilatory status more than low-intensity NPPV in stable AECOPD patients. Whether the application of high-intensity NPPV has therapeutic advantages over low-intensity NPPV in patients with AECOPD remains to be determined. The high-intensity versus low-intensity NPPV in patients with AECOPD (HAPPEN) study will examine whether high-intensity NPPV is more effective for correcting hypercapnia than low-intensity NPPV, hence reducing the need for intubation and improving survival.

METHODS/DESIGN

The HAPPEN study is a multicenter, two-arm, single-blind, prospective, randomized controlled trial. In total, 600 AECOPD patients with low to moderate hypercapnic respiratory failure will be included and randomized to receive high-intensity or low-intensity NPPV, with randomization stratified by study center. The primary endpoint is NPPV failure rate, defined as the need for endotracheal intubation and invasive ventilation. Secondary endpoints include the decrement of arterial carbon dioxide tension from baseline to 2 h after randomization, in-hospital and 28-day mortality, and 90-day survival. Patients will be followed up for 90 days after randomization.

DISCUSSION

The HAPPEN study will be the first randomized controlled study to investigate whether high-intensity NPPV better corrects hypercapnia and reduces the need for intubation and mortality in AECOPD patients than low-intensity NPPV. The results will help critical care physicians decide the intensity of NPPV delivery to patients with AECOPD.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02985918 . Registered on 7 December 2016.

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.

Management of severe acute exacerbations of COPD: an updated narrative review

Background

Patients with chronic obstructive pulmonary disease (COPD) may experience an acute worsening of respiratory symptoms that results in additional therapy; this event is defined as a COPD exacerbation (AECOPD). Hospitalization for AECOPD is accompanied by a rapid decline in health status with a high risk of mortality or other negative outcomes such as need for endotracheal intubation or intensive care unit (ICU) admission. Treatments for AECOPD aim to minimize the negative impact of the current exacerbation and to prevent subsequent events, such as relapse or readmission to hospital.

Main body

In this narrative review, we update the scientific evidence about the in-hospital pharmacological and non-pharmacological treatments used in the management of a severe AECOPD. We review inhaled bronchodilators, steroids, and antibiotics for the pharmacological approach, and oxygen, high flow nasal cannulae (HFNC) oxygen therapy, non-invasive mechanical ventilation (NIMV) and pulmonary rehabilitation (PR) as non-pharmacological treatments. We also review some studies of non-conventional drugs that have been proposed for severe AECOPD.

Conclusion

Several treatments exist for severe AECOPD patients requiring hospitalization. Some treatments such as steroids and NIMV (in patients admitted with a hypercapnic acute respiratory failure and respiratory acidosis) are supported by strong evidence of their efficacy. HFNC oxygen therapy needs further prospective studies. Although antibiotics are preferred in ICU patients, there is a lack of evidence regarding the preferred drugs and optimal duration of treatment for non-ICU patients. Early rehabilitation, if associated with standard treatment of patients, is recommended due to its feasibility and safety. There are currently few promising new drugs or new applications of existing drugs.

Risk Trajectories of Readmission and Death in the First Year after Hospitalization for Chronic Obstructive Pulmonary Disease

RATIONALE

Characterization of the dynamic nature of posthospital risk in chronic obstructive pulmonary disease (COPD) is needed to provide counseling and plan clinical services.

OBJECTIVES

To analyze risk of readmission and death after discharge for COPD among Medicare beneficiaries aged 65 years and older and to determine the association between ventilator support and risk trajectory.

METHODS

We computed daily absolute risks of hospital readmission and death for 1 year after discharge for COPD, stratified by ventilator support. We determined the time required for risks to decline by 50% from maximum daily values after discharge and for daily risks to plateau. We compared risks with those found in the general elderly population.

MEASUREMENTS AND MAIN RESULTS

Among 2,340,637 hospitalizations, the readmission rate at 1 year was 64.2%, including 63.5%, 66.0%, and 64.1% among those receiving invasive, noninvasive, and no ventilation, respectively. Among 1,283,069 hospitalizations, mortality at 1 year was 26.2%, including 45.7%, 41.8%, and 24.4% among those same respective groups. Daily risk of readmission declined by 50% within 28, 39, and 43 days and plateaued at 46, 54, and 61 days among those receiving invasive, noninvasive, and no ventilation, respectively. Risk of death declined by 50% by 3, 4, and 17 days and plateaued by 21, 18, and 24 days in the same respective groups. Risks of hospitalization and death were significantly higher after discharge for COPD than among the general Medicare population.

CONCLUSIONS

Discharge from the hospital is associated with prolonged risks of readmission and death that vary with need for ventilator support. Interventions limited to the first month after discharge may be insufficient to improve longitudinal outcomes.

Official ERS/ATS clinical practice guidelines: noninvasive ventilation for acute respiratory failure

Noninvasive mechanical ventilation (NIV) is widely used in the acute care setting for acute respiratory failure (ARF) across a variety of aetiologies. This document provides European Respiratory Society/American Thoracic Society recommendations for the clinical application of NIV based on the most current literature.The guideline committee was composed of clinicians, methodologists and experts in the field of NIV. The committee developed recommendations based on the GRADE (Grading, Recommendation, Assessment, Development and Evaluation) methodology for each actionable question. The GRADE Evidence to Decision framework in the guideline development tool was used to generate recommendations. A number of topics were addressed using technical summaries without recommendations and these are discussed in the supplementary material.This guideline committee developed recommendations for 11 actionable questions in a PICO (population-intervention-comparison-outcome) format, all addressing the use of NIV for various aetiologies of ARF. The specific conditions where recommendations were made include exacerbation of chronic obstructive pulmonary disease, cardiogenic pulmonary oedema, de novo hypoxaemic respiratory failure, immunocompromised patients, chest trauma, palliation, post-operative care, weaning and post-extubation.This document summarises the current state of knowledge regarding the role of NIV in ARF. Evidence-based recommendations provide guidance to relevant stakeholders.

Official ERS/ATS clinical practice guidelines: noninvasive ventilation for acute respiratory failure

Noninvasive mechanical ventilation (NIV) is widely used in the acute care setting for acute respiratory failure (ARF) across a variety of aetiologies. This document provides European Respiratory Society/American Thoracic Society recommendations for the clinical application of NIV based on the most current literature.The guideline committee was composed of clinicians, methodologists and experts in the field of NIV. The committee developed recommendations based on the GRADE (Grading, Recommendation, Assessment, Development and Evaluation) methodology for each actionable question. The GRADE Evidence to Decision framework in the guideline development tool was used to generate recommendations. A number of topics were addressed using technical summaries without recommendations and these are discussed in the supplementary material.This guideline committee developed recommendations for 11 actionable questions in a PICO (population-intervention-comparison-outcome) format, all addressing the use of NIV for various aetiologies of ARF. The specific conditions where recommendations were made include exacerbation of chronic obstructive pulmonary disease, cardiogenic pulmonary oedema, de novo hypoxaemic respiratory failure, immunocompromised patients, chest trauma, palliation, post-operative care, weaning and post-extubation.This document summarises the current state of knowledge regarding the role of NIV in ARF. Evidence-based recommendations provide guidance to relevant stakeholders.

Non-invasive ventilation for the management of acute hypercapnic respiratory failure due to exacerbation of chronic obstructive pulmonary disease

BACKGROUND

Non-invasive ventilation (NIV) with bi-level positive airway pressure (BiPAP) is commonly used to treat patients admitted to hospital with acute hypercapnic respiratory failure (AHRF) secondary to an acute exacerbation of chronic obstructive pulmonary disease (AECOPD).

OBJECTIVES

To compare the efficacy of NIV applied in conjunction with usual care versus usual care involving no mechanical ventilation alone in adults with AHRF due to AECOPD. The aim of this review is to update the evidence base with the goals of supporting clinical practice and providing recommendations for future evaluation and research.

SEARCH METHODS

We identified trials from the Cochrane Airways Group Specialised Register of trials (CAGR), which is derived from systematic searches of bibliographic databases including the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), the Allied and Complementary Medicine Database (AMED), and PsycINFO, and through handsearching of respiratory journals and meeting abstracts. This update to the original review incorporates the results of database searches up to January 2017.

SELECTION CRITERIA

All randomised controlled trials that compared usual care plus NIV (BiPAP) versus usual care alone in an acute hospital setting for patients with AECOPD due to AHRF were eligible for inclusion. AHRF was defined by a mean admission pH < 7.35 and mean partial pressure of carbon dioxide (PaCO2) > 45 mmHg (6 kPa). Primary review outcomes were mortality during hospital admission and need for endotracheal intubation. Secondary outcomes included hospital length of stay, treatment intolerance, complications, changes in symptoms, and changes in arterial blood gases.

DATA COLLECTION AND ANALYSIS

Two review authors independently applied the selection criteria to determine study eligibility, performed data extraction, and determined risk of bias in accordance with Cochrane guidelines. Review authors undertook meta-analysis for data that were both clinically and statistically homogenous, and analysed data as both one overall pooled sample and according to two predefined subgroups related to exacerbation severity (admission pH between 7.35 and 7.30 vs below 7.30) and NIV treatment setting (intensive care unit-based vs ward-based). We reported results for mortality, need for endotracheal intubation, and hospital length of stay in a 'Summary of findings' table and rated their quality in accordance with GRADE criteria.

MAIN RESULTS

We included in the review 17 randomised controlled trials involving 1264 participants. Available data indicate that mean age at recruitment was 66.8 years (range 57.7 to 70.5 years) and that most participants (65%) were male. Most studies (12/17) were at risk of performance bias, and for most (14/17), the risk of detection bias was uncertain. These risks may have affected subjective patient-reported outcome measures (e.g. dyspnoea) and secondary review outcomes, respectively.Use of NIV decreased the risk of mortality by 46% (risk ratio (RR) 0.54, 95% confidence interval (CI) 0.38 to 0.76; N = 12 studies; number needed to treat for an additional beneficial outcome (NNTB) 12, 95% CI 9 to 23) and decreased the risk of needing endotracheal intubation by 65% (RR 0.36, 95% CI 0.28 to 0.46; N = 17 studies; NNTB 5, 95% CI 5 to 6). We graded both outcomes as 'moderate' quality owing to uncertainty regarding risk of bias for several studies. Inspection of the funnel plot related to need for endotracheal intubation raised the possibility of some publication bias pertaining to this outcome. NIV use was also associated with reduced length of hospital stay (mean difference (MD) -3.39 days, 95% CI -5.93 to -0.85; N = 10 studies), reduced incidence of complications (unrelated to NIV) (RR 0.26, 95% CI 0.13 to 0.53; N = 2 studies), and improvement in pH (MD 0.05, 95% CI 0.02 to 0.07; N = 8 studies) and in partial pressure of oxygen (PaO2) (MD 7.47 mmHg, 95% CI 0.78 to 14.16 mmHg; N = 8 studies) at one hour. A trend towards improvement in PaCO2 was observed, but this finding was not statistically significant (MD -4.62 mmHg, 95% CI -11.05 to 1.80 mmHg; N = 8 studies). Post hoc analysis revealed that this lack of benefit was due to the fact that data from two studies at high risk of bias showed baseline imbalance for this outcome (worse in the NIV group than in the usual care group). Sensitivity analysis revealed that exclusion of these two studies resulted in a statistically significant positive effect of NIV on PaCO2. Treatment intolerance was significantly greater in the NIV group than in the usual care group (risk difference (RD) 0.11, 95% CI 0.04 to 0.17; N = 6 studies). Results of analysis showed a non-significant trend towards reduction in dyspnoea with NIV compared with usual care (standardised mean difference (SMD) -0.16, 95% CI -0.34 to 0.02; N = 4 studies). Subgroup analyses revealed no significant between-group differences.

AUTHORS' CONCLUSIONS

Data from good quality randomised controlled trials show that NIV is beneficial as a first-line intervention in conjunction with usual care for reducing the likelihood of mortality and endotracheal intubation in patients admitted with acute hypercapnic respiratory failure secondary to an acute exacerbation of chronic obstructive pulmonary disease (COPD). The magnitude of benefit for these outcomes appears similar for patients with acidosis of a mild (pH 7.30 to 7.35) versus a more severe nature (pH < 7.30), and when NIV is applied within the intensive care unit (ICU) or ward setting.

One-year and long-term mortality in patients hospitalized for chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality worldwide. Identifying potentially-modifiable predictors of mortality could help optimize COPD patient management. The aim of this study is to determine long-term mortality following hospitalization due to acute exacerbations of COPD (AECOPD), as well as AECOPD mortality predictors.

METHODS

We conducted a retrospective study by reviewing the medical records of all patients admitted with AECOPD in the University Hospital Complex of Santiago de Compostela in 2007 and 2008. In order to identify variables independently associated with mortality, we conducted a multivariate Cox proportional hazard regression analysis including those variables which proved to be significant in the univariate analysis.

RESULTS

Seven hundred and fifty seven patients were assessed. Patient mean age was 74.8 years and males accounted for 77% of all patients. Mean stay was 12.2 days. Three point six percent of all patients required intensive care. As for mortality rates, 1-year mortality was 26.2%, and 5-year mortality was 64.3%. In both scenarios, the most frequent causes of death were respiratory and cardiovascular disorders. Factors independently associated with mortality were older age, hospitalization by internal medicine (IMU), length of stay, the need for mechanical ventilation (MV) or noninvasive mechanical ventilation (NIV), early readmission, and history of atrial fibrillation (AF) and dementia.

CONCLUSIONS

In patients with COPD, age, exacerbation severity and comorbidity have long-term prognostic significance.

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

Background

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

Methods

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

Results

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

Conclusion

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

Natural history and risk stratification of patients undergoing non-invasive ventilation in a non-ICU setting for severe COPD exacerbations

Non-invasive ventilation (NIV) delivered in an intensive care unit (ICU) has become the cornerstone in the treatment of patients with severe chronic obstructive pulmonary disease (COPD) exacerbations. A trend towards managing these patients in non-ICU setting has emerged in recent years, although out-of-hospital survival by this approach and how to prognosticate it is unknown. We aimed to investigate these issues. We consecutively recruited 100 patients (49 males; median age 82 years) who received NIV treatment for acute respiratory failure due to COPD exacerbation in non-ICU medical wards of our hospital, between November 2008 and July 2012. We assessed survival (both in-hospital and out-of-hospital) of all these patients, and analyzed baseline parameters in a Cox proportional hazards model to develop a prognostic score. The median survival in the study population was 383 days (240-980). Overall survival rates were 71.0, 65.3, and 52.7 % at 1, 3, and 12 months, respectively. Age >85 years, a history of heart disorders and a neutrophil count ≥10 × 10(9) were associated with higher mortality at Cox's analysis (χ (2) = 35.766, p = 0.0001), and were used to build a prognostic score (NC85). The presence of two or more factors determined the deepest drop in survival (when NC85 ≥2, mortality at 1, 3, and 12 was 60.7, 70.4, and 77.2 %, respectively, while when NC85 = 0 were 4.0, 4.0, and 14.0 %). A simple model, based on three variables (age, neutrophil count and history of heart disease), accurately predicts survival of COPD patients receiving NIV in a non-ICU setting.

Noninvasive ventilation for severely acidotic patients in respiratory intermediate care units : Precision medicine in intermediate care units

Background

Severe acidosis can cause noninvasive ventilation (NIV) failure in chronic obstructive pulmonary disease (COPD) patients with acute hypercapnic respiratory failure (AHRF). NIV is therefore contraindicated outside of intensive care units (ICUs) in these patients. Less is known about NIV failure in patients with acute cardiogenic pulmonary edema (ACPE) and obesity hypoventilation syndrome (OHS). Therefore, the objective of the present study was to compare NIV failure rates between patients with severe and non-severe acidosis admitted to a respiratory intermediate care unit (RICU) with AHRF resulting from ACPE, COPD or OHS.

Methods

We prospectively included acidotic patients admitted to seven RICUs, where they were provided NIV as an initial ventilatory support measure. The clinical characteristics, pH evolutions, hospitalization or RICU stay durations and NIV failure rates were compared between patients with a pH ≥ 7.25 and a pH < 7.25. Logistic regression analysis was performed to determine the independent risk factors contributing to NIV failure.

Results

We included 969 patients (240 with ACPE, 540 with COPD and 189 with OHS). The baseline rates of severe acidosis were similar among the groups (45 % in the ACPE group, 41 % in the COPD group, and 38 % in the OHS group). Most of the patients with severe acidosis had increased disease severity compared with those with non-severe acidosis: the APACHE II scores were 21 ± 7.2 and 19 ± 5.8 for the ACPE patients (p < 0.05), 20 ± 5.7 and 19 ± 5.1 for the COPD patients (p < 0.01) and 18 ± 5.9 and 17 ± 4.7 for the OHS patients, respectively (NS). The patients with severe acidosis also exhibited worse arterial blood gas parameters: the PaCO₂ levels were 87 ± 22 and 70 ± 15 in the ACPE patients (p < 0.001), 87 ± 21 and 76 ± 14 in the COPD patients, and 83 ± 17 and 74 ± 14 in the OHS patients (NS)., respectively Further, the patients with severe acidosis required a longer duration to achieve pH normalization than those with non-severe acidosis (patients with a normalized pH after the first hour: ACPE, 8 % vs. 43 %, p < 0.001; COPD, 11 % vs. 43 %, p < 0.001; and OHS, 13 % vs. 51 %, p < 0.001), and they had longer RICU stays, particularly those in the COPD group (ACPE, 4 ± 3.1 vs. 3.6 ± 2.5, NS; COPD, 5.1 ± 3 vs. 3.6 ± 2.1, p < 0.001; and OHS, 4.3 ± 2.6 vs. 3.7 ± 3.2, NS). The NIV failure rates were similar between the patients with severe and non-severe acidosis in the three disease groups (ACPE, 16 % vs. 12 %; COPD, 7 % vs. 7 %; and OHS, 11 % vs. 4 %). No common predictive factor for NIV failure was identified among the groups.

Conclusions

ACPE, COPD and OHS patients with AHRF and severe acidosis (pH ≤ 7.25) who are admitted to an RICU can be successfully treated with NIV in these units. These results may be used to determine precise RICU admission criteria.

Electronic supplementary material

The online version of this article (doi:10.1186/s12890-016-0262-9) contains supplementary material, which is available to authorized users.

Non-Invasive Ventilation in the Management of Acute Respiratory Failure in Pakistan

Data were collected from hospital records on all patients who received non-invasive ventilation (NIV) during the period 1999-2000. Patients were treated with NIV if they had type I or type II respiratory failure or if they had respiratory distress with a respiratory rate above 30/min.

A total of 68 patients (35 males) were studied. NIV was applied using a Respironics Bi-PAP device mostly on a high-dependency unit (HDU). A successful outcome with NIV was achieved in 70% (26/37) of patients with type II failure, 65% (11/17) patients with type I failure and 64% (9/14) patients with respiratory distress. Of the 16 patients considered to be inappropriate for invasive ventilation on admission, eight were treated successfully with NIV.

NIV can be applied successfully in developing countries.

Can patients with moderate to severe acute respiratory failure from COPD be treated safely with noninvasive mechanical ventilation on the ward?

Purpose

Noninvasive mechanical ventilation (NIMV) usage outside of intensive care unit is not recommended in patients with COPD for severe acute respiratory failure (ARF). We assessed the factors associated with failure of NIMV in patients with ARF and severe acidosis admitted to the emergency department and followed on respiratory ward.

Patients and methods

This is a retrospective observational cohort study conducted in a tertiary teaching hospital specialized in chest diseases and thoracic surgery between June 1, 2013 and May 31, 2014. COPD patients who were admitted to our emergency department due to ARF were included. Patients were grouped according to the severity of acidosis into two groups: group 1 (pH=7.20–7.25) and group 2 (pH=7.26–7.30).

Results

Group 1 included 59 patients (mean age: 70±10 years, 30.5% female) and group 2 included 171 patients (mean age: 67±11 years, 28.7% female). On multivariable analysis, partial arterial oxygen pressure to the inspired fractionated oxygen (PaO₂/FiO₂) ratio <200, delta pH value <0.30, and pH value <7.31 on control arterial blood gas after NIMV in the emergency room and peak C-reactive protein were found to be the risk factors for NIMV failure in COPD patients with ARF in the ward.

Conclusion

NIMV is effective not only in mild respiratory failure but also with severe forms of COPD patients presenting with severe exacerbation. The determination of the failure criteria of NIMV and the expertise of the team is critical for treatment success.

Acidemia in severe acute cardiogenic pulmonary edema treated with noninvasive pressure support ventilation: a single-center experience

In clinical practice, acidotic patients with acute cardiogenic pulmonary edema (ACPE) are commonly considered more severe in comparison with nonacidotic patients, and data on the outcome of these patients treated with noninvasive pressure support ventilation (NIV) are lacking.The present investigation was aimed at assessing whether acidosis on admission (pH < 7.35) was associated with adverse outcome in 65 consecutive patients with ACPE treated with NIV and admitted to our Intensive Cardiac Care Unit (ICCU).In our population, 28 patients were acidotic (28 of 65, 43.1%), whereas 41 patients were not (37 of 65, 56.9%). According to the Repeated Measures General Linear Model, pCO2 values significantly changed throughout the 2-h NIV treatment (P = 0.019) in both groups (P = 0001). In acidotic patients, pCO2 significantly decreased (51.9 ± 15.3 → 47.0 ± 12.8 → 44.8 ± 12.7), whereas they increased in the nonacidotic subgroup (36.8 ± 6.5 → 36.9 ± 7.2 → 37.6 ± 6.4). No difference was observed in intubation rate between acidotic (eight patients, 28.6%) and nonacidotic patients (12 patients, 32.4%) (P = 0.738). In-ICCU mortality rate did not differ between (13 patients, 35.1%) and nonacidotic patients (nine patients, 32.1%) (P = 0.801).Our data strongly suggest that in patients with severe ACPE treated with NIV, the presence of acidosis is not associated with adverse outcomes (early mortality and intubation rates) in these patients.

[Hypercapnic respiratory failure. Pathophysiology, indications for mechanical ventilation and management]

BACKGROUND

Acute hypercapnic respiratory failure is mostly seen in patients with chronic obstructive pulmonary disease (COPD) and obesity hypoventilation syndrome (OHS). Depending on the underlying cause it may be associated with hypoxemic respiratory failure and places high demands on mechanical ventilation.

OBJECTIVE

Presentation of the current knowledge on indications and management of mechanical ventilation in patients with hypercapnic respiratory failure.

MATERIAL AND METHODS

Review of the literature.

RESULTS

Important by the selection of mechanical ventilation procedures is recognition of the predominant pathophysiological component. In hypercapnic respiratory failure with a pH < 7.35 non-invasive ventilation (NIV) is primarily indicated unless there are contraindications. In patients with severe respiratory acidosis NIV requires a skilled and experienced team and close monitoring in order to perceive a failure of NIV. In acute exacerbation of COPD ventilator settings need a long expiration and short inspiration time to avoid further hyperinflation and an increase in intrinsic positive end-expiratory pressure (PEEP). Ventilation must be adapted to the pathophysiological situation in patients with OHS or overlap syndrome. If severe respiratory acidosis and hypercapnia cannot be managed by mechanical ventilation therapy alone extracorporeal venous CO2 removal may be necessary. Reports on this approach in awake patients are available.

CONCLUSION

The use of NIV is the predominant treatment in patients with hypercapnic respiratory failure but close monitoring is necessary in order not to miss the indications for intubation and invasive ventilation. Methods of extracorporeal CO2 removal especially in awake patients need further evaluation.

Early failure of noninvasive ventilation in chronic obstructive pulmonary disease with acute hypercapnic respiratory failure

Noninvasive ventilation (NIV) in the management of chronic obstructive pulmonary disease (COPD) patients with acute hypercapnic respiratory failure is considered a first-line therapy. However, patients who fail NIV and then require invasive mechanical ventilation have been found to have higher mortality than patients initially treated with invasive mechanical ventilation. We tried to find parameters associated with early NIV failure (need for intubation or death <24 h of starting NIV) in patients presenting to the ED with acute exacerbation of COPD. A retrospective analysis was conducted of the medical records of 218 patients with acute exacerbation of COPD visiting Asan Medical Center and managed with NIV during their stay in the ED from January 2007 to December 2013. NIV was successful in 200 (91.7%) and 18 (8.3%) had early NIV failure. Of the variables obtained before NIV treatment, heart rate (≥120/min: OR 2.5, 95% CI 1.2-7.0) and pH (7.25-7.29: OR 2.1, 95% CI 1.0-8.8; <7.25: OR 11.7, 95% CI 3.5-38.6) were significant factors associated with early NIV failure. Of the variables obtained after 1 h of NIV treatment, heart rate (≥120/min: OR 7.5, 95% CI 2.3-24.3) and pH (7.25-7.29: OR 4.7, 95% CI 1.5-15.1; <7.25: OR 20.9, 95% CI 5.4-61.2) were still significant. The presence of tachycardia and severe acidosis before NIV treatment and persistence of tachycardia and severe acidosis after 1 h of NIV treatment were associated with early NIV failure.

Nutritional Risk Screening 2002 as a Predictor of Outcome During General Ward-Based Noninvasive Ventilation in Chronic Obstructive Pulmonary Disease with Respiratory Failure

BACKGROUND Noninvasive ventilation (NIV) may reduce the need for intubation and mortality associated with chronic obstructive pulmonary disease (COPD) with type II respiratory failure. Early and simple predictors of NIV outcome could improve clinical management. This study aimed to assess whether nutritional risk screening 2002 (NRS2002) is a useful outcome predictor in COPD patients with type II respiratory failure treated by noninvasive positive pressure ventilation (NIPPV). MATERIAL AND METHODS This prospective observational study enrolled COPD patients with type II respiratory failure who accepted NIPPV. Patients were submitted to NRS2002 evaluation upon admission. Biochemical tests were performed the next day and blood gas analysis was carried out prior to NIPPV treatment and 4 hours thereafter. Patients were divided into NRS2002 score ≥3 and NRS2002 score <3 groups and NIV failure rates were compared between both groups. RESULTS Of the 233 patients, 71 (30.5%) were not successfully treated by NIPPV. The failure rate was significantly higher in the NRS2002 score ≥3 group (35.23%) in comparison with patients with NRS2002 score <3 (15.79%) (p<0.05). Multivariate analysis indicated that PaCO2 (OR 1.25, 95%CI 1.172-1.671, p<0.05) prior to NIPPV treatment and NRS2002 score ≥3 (OR 1.76, 95%CI 1.303-2.374, p<0.05) were independent predictive factors for NIPPV treatment failure. CONCLUSIONS NRS2002 score ≥3 and PaCO2 values at admission may predict unsuccessful NIPPV treatment of COPD patients with type II respiratory failure and help to adjust therapeutic strategies. NRS2002 is a noninvasive and simple method for predicting NIPPV treatment outcome.

Longitudinal change in quality of life following hospitalisation for acute exacerbations of COPD

Background

Current guidelines for management of patients hospitalised with acute exacerbations of chronic obstructive pulmonary disease (COPD) recommend that clinical decisions, including escalation to assisted ventilation, be informed by an estimate of the patients’ likely postdischarge quality of life. There is little evidence to inform predictions of outcome in terms of quality of life, psychological well-being and functional status. Undue nihilism might lead to denial of potentially life-saving therapy, while undue optimism might prolong suffering when alternative palliation would be more appropriate. This study aimed to detail longitudinal changes in quality of life following hospitalisation for acute exacerbations of COPD.

Methods

We prospectively recruited two cohorts (exacerbations requiring assisted ventilation during admission and exacerbations not ventilated). Admission clinical data, and mortality and readmission details were collected. Quality of life, psychological well-being and functional status were formally assessed over the subsequent 12 months. Time-adjusted mean change in quality of life was examined.

Results

183 patients (82 ventilated; 101 not ventilated) were recruited. On average, overall quality of life improved by a clinically important amount in those not ventilated and did not decline in ventilated patients. Both groups showed clinically important improvements in respiratory symptoms and an individual's sense of control over their condition, despite the tendency for functional status to decline.

Conclusions

On average, postdischarge quality of life improved in non-ventilated and did not decline in ventilated patients. Certain quality of life domains (ie, symptoms and mastery) improved significantly. Better understanding of longitudinal change in postdischarge quality of life should help to inform decision-making.

Using modeling to inform patient-centered care choices at the end of life

AIM

Advance directives are often under-informed due to a lack of disease-specific prognostic information. Without well-informed advance directives patients may receive default care that is incongruent with their preferences. We aimed to further inform advance care planning in patients with severe chronic obstructive pulmonary disease by estimating outcomes with alternative advance directives.

METHODS

We designed a Markov microsimulation model estimating outcomes for patients choosing between the Full Code advance directive (permitting invasive mechanical ventilation), and the Do Not Intubate directive (only permitting noninvasive ventilation).

RESULTS

Our model estimates Full Code patients have marginally increased one-year survival after admission for severe respiratory failure, but are more likely to be residing in a nursing home and have frequent rehospitalizations for respiratory failure.

CONCLUSION

Patients with severe chronic obstructive pulmonary disease may consider these potential tradeoffs between survival, rehospitalizations and institutionalization when making informed advance care plans and end-of-life decisions. We highlight outcomes research needs for variables most influential to the model's outcomes, including the risk of complications of invasive mechanical ventilation and failing noninvasive mechanical ventilation.

Chronic obstructive pulmonary disease: clinical review and update on consensus guidelines

In the last 2 decades, chronic obstructive pulmonary disease (COPD) has been increasingly recognized as a major public health problem. Since the introduction of the Global Initiative for Chronic Obstructive Lung Disease in 1998, growing interest in the pathogenesis and management of patients with COPD has led to notable improvements in patient care and quality of life. Despite greater awareness of this common preventable disease and major therapeutic advances during this period, the global impact of COPD remains strikingly large. We provide an evidence-based clinical review on COPD, with a focus on internists as the target audience.

Mechanisms of striated muscle dysfunction during acute exacerbations of COPD

During acute exacerbations of chronic obstructive pulmonary disease (COPD), limb and respiratory muscle dysfunction develops rapidly and functional recovery is partial and slow. The mechanisms leading to this muscle dysfunction are not yet fully established. However, recent evidence has shown that several pathways involved in muscle catabolism, apoptosis, and oxidative stress are activated in the vastus lateralis muscle of patients during acute exacerbations of COPD, while those implicated in mitochondrial function are downregulated. These pathways may be targeted in different ways by factors related to exacerbations. These factors include enhanced systemic inflammation, oxidative stress, impaired energy balance, hypoxia, hypercapnia and acidosis, corticosteroid treatment, and physical inactivity. Data on the respiratory muscles are limited, but these muscles are undoubtedly overloaded during exacerbations. While they are also subjected to the same systemic elements as the limb muscles (except for inactivity), they also face a specific mechanical disadvantage caused by changes in lung volume during exacerbation. The latter will affect the ability to generate force by the foreshortening of the muscle (especially for the diaphragm), but also by altering rib orientation and motion (especially for the parasternal intercostals and the external intercostals). Because acute exacerbations of COPD are associated with an increase in both prevalence and severity of generalized muscle dysfunction, and both remain present even during recovery, early interventions to minimize muscle dysfunction during exacerbation are warranted. Although rehabilitation may be promising, other therapeutic strategies such as counterbalancing the adverse effects of exacerbations on skeletal muscle pathways may also be used.

Management of COPD patients in the intensive care unit

Chronic obstructive pulmonary disease (COPD) is characterized by expiratory airflow limitation that is not fully reversible. Acute exacerbations in patients with moderate to severe COPD can cause severe hypoxia and persistent or severe respiratory acidosis, resulting in respiratory failure and the need for ventilator support. Acute respiratory failure, altered mental status, and hemodynamic instability associated with acute exacerbations of COPD are commonly encountered and require careful management in the intensive care unit (ICU). Noninvasive and invasive ventilator support in conjunction with pharmacotherapy can be lifesaving, although mortality remains high. It is important also to consider pulmonary rehabilitation and palliative care.

Hospital management of patients with exacerbation of severe chronic obstructive pulmonary disease

The article assesses the originally developed criteria of clinical stability and treatment protocol in the hospital management and discharge procedures of patients with exacerbations of severe chronic obstructive pulmonary disease (COPD). The study included 34 patients (26 males, 8 females), aged 58-80 years, hospitalized due to exacerbation of severe (23 patients) and very severe (11 patients) COPD. On admission, the mean FEV1 was 0.78 ± 0.22 L (31.7% ± 8.2% of predicted), FVC 2.52 ± 0.87 L (77.9% ± 9.8% of predicted) and FEV1/FVC 33.17% ± 10.84%. Before hospitalization, 10 out of the 34 patients were diagnosed with chronic respiratory failure. All patients were treated according the same treatment protocol which included the developed criteria of clinical stability. Meeting all these criteria in a 24-h observation period was the basis to slash the dose of systemic glucocorticosteroids by half. The maintenance of the stability criteria through the subsequent 24 h allowed discharging a patient from the hospital. Every patient was supplied with a detailed plan of out-of-hospital treatment. The results show that the mean duration of hospitalization was 6.4 ± 4.8 days. Only one patient required readmission within 4 weeks after discharge. Two patients died; one during the hospitalization time and the other after discharge. In the latter case, death was not directly related to the COPD exacerbation. In conclusion, the protocol of treatment and the criteria of stability used for patients with COPD exacerbation enabled to optimize the hospitalization time. A shortening of hospitalization was not associated with increased risk of readmission within 4 weeks after discharge.

[Non-invasive respiratory unit in the Hungarian health care system]

Treating patients with acute or chronic respiratory insufficiency still poses a major load on the healthcare system. Though there is evidence that treating these patients in high dependency respiratory units results in a shortening of hospital stay, reduces the need of intubation, and decreases mortality. In the Hungarian routine these patients are treated in general wards until the development of global respiratory insufficiency, when they are transferred to intensive care units. The authors present their first year experience on their novel Non-invasive Respiratory Unit established at Semmelweis University.

Noninvasive positive pressure ventilation for acute respiratory failure patients with chronic obstructive pulmonary disease (COPD): an evidence-based analysis

Objective

The objective of this evidence-based analysis was to examine the effectiveness, safety, and cost-effectiveness of noninvasive positive pressure ventilation (NPPV ) in the following patient populations: patients with acute respiratory failure (ARF ) due to acute exacerbations of chronic obstructive pulmonary disease (COPD ); weaning of COPD patients from invasive mechanical ventilation (IMV ); and prevention of or treatment of recurrent respiratory failure in COPD patients after extubation from IMV.

Clinical Need and Target Population

Technology

There are several treatment options for ARF. Usual medical care (UMC ) attempts to facilitate adequate oxygenation and treat the cause of the exacerbation, and typically consists of supplemental oxygen, and a variety of medications such as bronchodilators, corticosteroids, and antibiotics. The failure rate of UMC is high and has been estimated to occur in 10% to 50% of cases.

The alternative is mechanical ventilation, either invasive or noninvasive. Invasive mechanical ventilation involves sedating the patient, creating an artificial airway through endotracheal intubation, and attaching the patient to a ventilator. While this provides airway protection and direct access to drain sputum, it can lead to substantial morbidity, including tracheal injuries and ventilator-associated pneumonia (VAP ).

While both positive and negative pressure noninvasive ventilation exists, noninvasive negative pressure ventilation such as the iron lung is no longer in use in Ontario. Noninvasive positive pressure ventilation provides ventilatory support through a facial or nasal mask and reduces inspiratory work. Noninvasive positive pressure ventilation can often be used intermittently for short periods of time to treat respiratory failure, which allows patients to continue to eat, drink, talk, and participate in their own treatment decisions. In addition, patients do not require sedation, airway defence mechanisms and swallowing functions are maintained, trauma to the trachea and larynx are avoided, and the risk for VAP is reduced. Common complications are damage to facial and nasal skin, higher incidence of gastric distension with aspiration risk, sleeping disorders, and conjunctivitis. In addition, NPPV does not allow direct access to the airway to drain secretions and requires patients to cooperate, and due to potential discomfort, compliance and tolerance may be low.

In addition to treating ARF, NPPV can be used to wean patients from IMV through the gradual removal of ventilation support until the patient can breathe spontaneously. Five to 30% of patients have difficultly weaning. Tapering levels of ventilatory support to wean patients from IMV can be achieved using IMV or NPPV. The use of NPPV helps to reduce the risk of VAP by shortening the time the patient is intubated.

Following extubation from IMV, ARF may recur, leading to extubation failure and the need for reintubation, which has been associated with increased risk of nosocomial pneumonia and mortality. To avoid these complications, NPPV has been proposed to help prevent ARF recurrence and/or to treat respiratory failure when it recurs, thereby preventing the need for reintubation.

Research Questions

Research Methods

Summary of Findings

Conclusions

Informing shared decisions about advance directives for patients with severe chronic obstructive pulmonary disease: a modeling approach

OBJECTIVE

To estimate the survival and quality-adjusted life-years (QALYs) of Full Code versus Do Not Intubate (DNI) advance directives in patients with severe chronic obstructive pulmonary disease and to evaluate how patient preferences and place of residence influence these outcomes.

METHODS

A Markov decision model using published data for COPD exacerbation outcomes. The advance directives that were modeled were as follows: DNI, allowing only noninvasive mechanical ventilation, or Full Code, allowing all forms of mechanical ventilation including invasive mechanical ventilation with endotracheal tube (ETT) insertion.

RESULTS

In community-dwellers, Full Code resulted in a greater likelihood of survival and higher QALYs (4-year survival: 23% Full Code, 18% DNI; QALYs: 1.34 Full Code, 1.24 DNI). When considering patient preferences regarding complications, however, if patients were willing to give up >3 months of life expectancy to avoid ETT complications, or >1 month of life expectancy to avoid long-term institutionalization, DNI resulted in higher QALYs. For patients in long-term institutions, DNI resulted in a greater likelihood of survival and higher QALYs (4-year survival: 2% DNI, 1% Full Code; QALYs: 0.29 DNI, 0.24 Full Code). In sensitivity analyses, the model was sensitive to the probabilities of ETT complication and noninvasive mechanical ventilation failure and to patient preferences about ETT complications and long-term institutionalization.

CONCLUSION

Our model demonstrates that patient preferences regarding ETT complications and long-term institutionalization, as well as baseline place of residence, affect the advance directive recommendation when considered in terms of both survival and QALYs. Decision modeling can demonstrate the potential trade-off between survival and quality of life, using patient preferences and disease-specific data, to inform the shared advance directive decision.

Outcomes of noninvasive ventilation for acute exacerbations of chronic obstructive pulmonary disease in the United States, 1998-2008

RATIONALE

The patterns and outcomes of noninvasive, positive-pressure ventilation (NIPPV) use in patients hospitalized for acute exacerbations of chronic obstructive pulmonary disease (COPD) nationwide are unknown.

OBJECTIVES

To determine the prevalence and trends of noninvasive ventilation for acute COPD.

METHODS

We used data from the Healthcare Cost and Utilization Project's Nationwide Inpatient Sample to assess the pattern and outcomes of NIPPV use for acute exacerbations of COPD from 1998 to 2008.

MEASUREMENTS AND MAIN RESULTS

An estimated 7,511,267 admissions for acute exacerbations occurred from 1998 to 2008. There was a 462% increase in NIPPV use (from 1.0 to 4.5% of all admissions) and a 42% decline in invasive mechanical ventilation (IMV) use (from 6.0 to 3.5% of all admissions) during these years. This was accompanied by an increase in the size of a small cohort of patients requiring transition from NIPPV to IMV. In-hospital mortality in this group appeared to be worsening over time. By 2008, these patients had a high mortality rate (29.3%), which represented 61% higher odds of death compared with patients directly placed on IMV (95% confidence interval, 24-109%) and 677% greater odds of death compared with patients treated with NIPPV alone (95% confidence interval, 475-948%). With the exception of patients transitioned from NIPPV to IMV, in-hospital outcomes were favorable and improved steadily year by year.

CONCLUSIONS

The use of NIPPV has increased significantly over time among patients hospitalized for acute exacerbations of COPD, whereas the need for intubation and in-hospital mortality has declined. However, the rising mortality rate in a small but expanding group of patients requiring invasive mechanical ventilation after treatment with noninvasive ventilation needs further investigation.

A case-based approach to noninvasive positive pressure ventilation

Noninvasive positive pressure ventilation (NIPPV) has revolutionized the concept of mechanical ventilation with the major benefit of avoiding invasive mechanical ventilation in specific situations, thereby preventing associated complications. Noninvasive positive pressure ventilation has emerged as the first line of management of hypercapnic respiratory failure (due to chronic obstructive pulmonary disease and neuromuscular weakness) and cardiogenic pulmonary edema in addition to standard therapy in the acute setting. There is improvement in gas exchange, relief of respiratory muscle fatigue, and clinical outcome with reduced morbidity and mortality. Nevertheless, contraindications and failures need to be identified early, as delaying endotracheal intubation is associated with increased morbidity and mortality. Despite overwhelming evidence to support its use, NIPPV is underused. Residents and hospitalists need to identify NIPPV as a treatment option in acute respiratory failure.