Noninvasive versus conventional ventilation to treat hypercapnic encephalopathy in chronic obstructive pulmonary disease

Exploring Heterogeneity in the Cost-Effectiveness of High-Flow Nasal Cannula Therapy in Acutely Ill Children-Insights From the Step-Up First-line Support for Assistance in Breathing in Children Trial Using a Machine Learning Method

OBJECTIVES

To investigate heterogeneity in the cost-effectiveness of high-flow nasal cannula (HFNC) therapy compared with continuous positive airway pressure (CPAP) for acutely ill children requiring noninvasive respiratory support.

METHODS

Using data from the First-line Support for Assistance in Breathing in Children trial, we explore heterogeneity at the patient and subgroup levels using 2 causal forest approaches and a seemingly unrelated regression approach for comparison. First-line Support for Assistance in Breathing in Children is a noninferiority randomized controlled trial (ISRCTN60048867) involving 24 UK pediatric intensive care units. The Step-up trial focuses on acutely ill children aged 0 to 15 years, requiring noninvasive respiratory support. A total of 600 children were randomly assigned to HFNC and CPAP groups in a 1:1 allocation ratio, with 94 patients excluded because of data unavailability.

RESULTS

The primary outcome is the incremental net monetary benefit (INB) of HFNC compared with CPAP, using a willingness-to-pay threshold of £20 000 per quality-adjusted life year gain. INB is derived from total costs and quality-adjusted life years at 6 months. Subgroup analysis showed that some subgroups, such as male children, those aged less than 12 months, and those without severe respiratory distress at randomization, had more favorable INB results. Patient-level analysis revealed heterogeneity in INB estimates, particularly driven by the cost component, with greater uncertainty for those with higher INBs.

CONCLUSIONS

The estimated overall INB of HFNC is significantly larger for specific patient subgroups, suggesting that the cost-effectiveness of HFNC can be heterogeneous, which highlights the importance of considering patient characteristics in evaluating the cost-effectiveness of HFNC.

The use of high-flow nasal cannula in patients with chronic obstructive pulmonary disease under exacerbation and stable phases: A systematic review and meta-analysis

BACKGROUND

High-flow nasal cannula (HFNC) has been increasingly utilized in patients with chronic obstructive pulmonary disease (COPD); however, the effects on reducing the need for intubation or reintubation remain unclear.

OBJECTIVES

We aimed to investigate whether HFNC therapy was superior to conventional oxygen therapy (COT) or noninvasive ventilation (NIV) in patients with COPD.

METHODS

A literature search was performed in electronic databases until October 1st, 2022. The primary outcome was the need for intubation/reintubation. All analyses were performed using R (version 4.0.3) and STATA SE (version 15.1).

RESULTS

When HFNC therapy was compared with NIV in patients with COPD under initial respiratory support and postextubation, no significant differences were found in the risk of intubation (RR 0.84, 95% CI 0.36 to 1.98) and reintubation (RR 1.35, 95% CI 0.73 to 2.50). Compared to NIV, HFNC therapy did not decrease the partial pressure of carbon dioxide or increase the partial pressure of oxygen to the fraction of inspired oxygen. However, HFNC therapy was associated with a lower incidence of skin breakdown (RR 0.52, 95% CI 0.39 to 0.69) and a higher comfort score (SMD 0.90, 95% CI 0.60 to 1.20) than NIV. When HFNC therapy was compared with COT during initial respiratory treatment for COPD exacerbation, a lower risk of treatment failure was found (RR 0.58, 95% CI 0.37 to 0.89). When HFNC therapy was compared with long-term oxygen therapy, quality of life (measured by SGRQ-C) was significantly improved (SMD -0.42, 95% CI -0.69 to -0.14).

CONCLUSION

HFNC therapy might be used as an alternative to NIV for COPD exacerbation with mild-moderate hypercapnia under close monitoring and is a potential domiciliary treatment for stable COPD.

Noninvasive Ventilation and High-Flow Nasal Therapy Administration in Chronic Obstructive Pulmonary Disease Exacerbations

Noninvasive ventilation (NIV) is considered to be the standard of care for the management of acute hypercapnic respiratory failure in patients with chronic obstructive pulmonary disease exacerbation. It can be delivered safely in any dedicated setting, from emergency rooms to high dependency or intensive care units and wards. NIV helps improving dyspnea and gas exchange, reduces the need for endotracheal intubation, and morbidity and mortality rates. It is therefore recognized as the gold standard in this condition. High-flow nasal therapy helps improving ventilatory efficiency and reducing the work of breathing in patients with severe chronic obstructive pulmonary disease. Early studies indicate that some patients with acute hypercapnic respiratory failure can be managed with high-flow nasal therapy, but more information is needed before specific recommendations for this therapy can be made. Therefore, high-flow nasal therapy use should be individualized in each particular situation and institution, taking into account resources, and local and personal experience with all respiratory support therapies.

Ventilator Support and Oxygen Therapy in Palliative and End-of-Life Care in the Elderly

Elderly patients suffering from chronic cardio-pulmonary diseases commonly experience acute respiratory failure. As in younger patients, a well-known therapeutic approach of noninvasive mechanical ventilation is able to prevent orotracheal intubation in a large number of severe scenarios in elderly patients. In addition, this type of ventilation is frequently applied in elderly patients who refuse intubation for invasive mechanical ventilation. The rate of failure of noninvasive ventilation may be reduced by means of the integration of new technological devices (i.e., high-flow nasal cannula, extracorporeal CO₂ removal, cough assistance and high-frequency chest wall oscillation, and fiberoptic bronchoscopy). Ethical issues with end-of-life decisions and the choice of the environment are not clearly defined in the treatment of elderly with acute respiratory insufficiency.

Noninvasive ventilation in acute respiratory failure: which recipe for success?

Noninvasive positive-pressure ventilation (NPPV) to treat acute respiratory failure has expanded tremendously over the world in terms of the spectrum of diseases that can be successfully managed, the locations of its application and achievable goals.

The turning point for the successful expansion of NPPV is its ability to achieve the same physiological effects as invasive mechanical ventilation with the avoidance of the life-threatening risks correlated with the use of an artificial airway.

Cardiorespiratory arrest, extreme psychomotor agitation, severe haemodynamic instability, nonhypercapnic coma and multiple organ failure are absolute contraindications for NPPV. Moreover, pitfalls of NPPV reduce its rate of success; consistently, a clear plan of what to do in case of NPPV failure should be considered, especially for patients managed in unprotected setting. NPPV failure is likely to be reduced by the application of integrated therapeutic tools in selected patients handled by expert teams.

In conclusion, NPPV has to be considered as a rational art and not just as an application of science, which requires the ability of clinicians to both choose case-by-case the best “ingredients” for a “successful recipe” (i.e.patient selection, interface, ventilator, interface,etc.) and to avoid a delayed intubation if the ventilation attempt fails.

A Multicenter Randomized Trial Assessing the Efficacy of Helium/Oxygen in Severe Exacerbations of Chronic Obstructive Pulmonary Disease

RATIONALE

During noninvasive ventilation (NIV) for chronic obstructive pulmonary disease (COPD) exacerbations, helium/oxygen (heliox) reduces the work of breathing and hypercapnia more than air/O₂, but its impact on clinical outcomes remains unknown.

OBJECTIVES

To determine whether continuous administration of heliox for 72 hours, during and in-between NIV sessions, was superior to air/O₂ in reducing NIV failure (25-15%) in severe hypercapnic COPD exacerbations.

METHODS

This was a prospective, randomized, open-label trial in 16 intensive care units (ICUs) and 6 countries. Inclusion criteria were COPD exacerbations with Pa_CO2 ≥ 45 mm Hg, pH ≤ 7.35, and at least one of the following: respiratory rate ≥ 25/min, Pa_O2 ≤ 50 mm Hg, and oxygen saturation (arterial [Sa_O2] or measured by pulse oximetry [Sp_O2]) ≤ 90%. A 6-month follow-up was performed.

MEASUREMENTS AND MAIN RESULTS

The primary endpoint was NIV failure (intubation or death without intubation in the ICU). The secondary endpoints were physiological parameters, duration of ventilation, duration of ICU and hospital stay, 6-month recurrence, and rehospitalization rates. The trial was stopped prematurely (445 randomized patients) because of a low global failure rate (NIV failure: air/O₂ 14.5% [n = 32]; heliox 14.7% [n = 33]; P = 0.97, and time to NIV failure: heliox group 93 hours [n = 33], air/O₂ group 52 hours [n = 32]; P = 0.12). Respiratory rate, pH, Pa_CO2, and encephalopathy score improved significantly faster with heliox. ICU stay was comparable between the groups. In patients intubated after NIV failed, patients on heliox had a shorter ventilation duration (7.4 ± 7.6 d vs. 13.6 ± 12.6 d; P = 0.02) and a shorter ICU stay (15.8 ± 10.9 d vs. 26.7 ± 21.0 d; P = 0.01). No difference was observed in ICU and 6-month mortality.

CONCLUSIONS

Heliox improves respiratory acidosis, encephalopathy, and the respiratory rate more quickly than air/O₂ but does not prevent NIV failure. Overall, the rate of NIV failure was low. Clinical trial registered with www.clinicaltrials.gov (NCT 01155310).

Early use of noninvasive techniques for clearing respiratory secretions during noninvasive positive-pressure ventilation in patients with acute exacerbation of chronic obstructive pulmonary disease and hypercapnic encephalopathy: A prospective cohort study

Noninvasive positive-pressure ventilation (NPPV) might be superior to conventional mechanical ventilation (CMV) in patients with acute exacerbations of chronic obstructive pulmonary disease (AECOPDs). Inefficient clearance of respiratory secretions provokes NPPV failure in patients with hypercapnic encephalopathy (HE). This study compared CMV and NPPV combined with a noninvasive strategy for clearing secretions in HE and AECOPD patients.The present study is a prospective cohort study of AECOPD and HE patients enrolled between October 2013 and August 2015 in a critical care unit of a major university teaching hospital in China.A total of 74 patients received NPPV and 90 patients received CMV. Inclusion criteria included the following: physician-diagnosed AECOPD, spontaneous airway clearance of excessive secretions, arterial blood gas analysis requiring intensive care, moderate-to-severe dyspnea, and a Kelly-Matthay scale score of 3 to 5. Exclusion criteria included the following: preexisting psychiatric/neurological disorders unrelated to HE, upper gastrointestinal bleeding, upper airway obstruction, acute coronary syndromes, preadmission tracheostomy or endotracheal intubation, and urgent endotracheal intubation for cardiovascular, psychomotor agitation, or severe hemodynamic conditions.Intensive care unit participants were managed by NPPV. Participants received standard treatment consisting of controlled oxygen therapy during NPPV-free periods; antibiotics, intravenous doxofylline, corticosteroids (e.g., salbutamol and ambroxol), and subcutaneous low-molecular-weight heparin; and therapy for comorbidities if necessary. Nasogastric tubes were inserted only in participants who developed gastric distension. No pharmacological sedation was administered.The primary and secondary outcome measures included comparative complication rates, durations of ventilation and hospitalization, number of invasive devices/patient, and in-hospital and 1-year mortality rates.Arterial blood gases and sensorium levels improved significantly within 2 hours in the NPPV group with lower hospital mortality, fewer complications and invasive devices/patient, and superior weaning off mechanical ventilation. Mechanical ventilation duration, hospital stay, or 1-year mortality was similar between groups.NPPV combined with a noninvasive strategy to clear secretions during the first 2 hours may offer advantages over CMV in treating AECOPD patients complicated by HE.

Challenges on non-invasive ventilation to treat acute respiratory failure in the elderly

Acute respiratory failure is a frequent complication in elderly patients especially if suffering from chronic cardio-pulmonary diseases. Non-invasive mechanical ventilation constitutes a successful therapeutic tool in the elderly as, like in younger patients, it is able to prevent endotracheal intubation in a wide range of acute conditions; moreover, this ventilator technique is largely applied in the elderly in whom invasive mechanical ventilation is considered not appropriated. Furthermore, the integration of new technological devices, ethical issues and environment of treatment are still largely debated in the treatment of acute respiratory failure in the elderly.

This review aims at reporting and critically analyzing the peculiarities in the management of acute respiratory failure in elderly people, the role of noninvasive mechanical ventilation, the potential advantages of applying alternative or integrated therapeutic tools (i.e. high-flow nasal cannula oxygen therapy, non-invasive and invasive cough assist devices and low-flow carbon-dioxide extracorporeal systems), drawbacks in physician’s communication and “end of life” decisions. As several areas of this topic are not supported by evidence-based data, this report takes in account also “real-life” data as well as author’s experience.

The choice of the setting and of the timing of non-invasive mechanical ventilation in elderly people with advanced cardiopulmonary disease should be carefully evaluated together with the chance of using integrated or alternative supportive devices. Last but not least, economic and ethical issues may often challenges the behavior of the physicians towards elderly people who are hospitalized for acute respiratory failure at the end stage of their cardiopulmonary and neoplastic diseases.

Comparative Effectiveness of Noninvasive and Invasive Ventilation in Critically Ill Patients With Acute Exacerbation of Chronic Obstructive Pulmonary Disease

OBJECTIVES

To compare the characteristics and hospital outcomes of patients with an acute exacerbation of chronic obstructive pulmonary disease treated in the ICU with initial noninvasive ventilation or invasive mechanical ventilation.

DESIGN

Retrospective, multicenter cohort study of prospectively collected data. We used propensity matching to compare the outcomes of patients treated with noninvasive ventilation to those treated with invasive mechanical ventilation. We also assessed predictors for noninvasive ventilation failure.

SETTING

Thirty-eight hospitals participating in the Acute Physiology and Chronic Health Evaluation database from 2008 through 2012.

SUBJECTS

A total of 3,520 patients with a diagnosis of chronic obstructive pulmonary disease exacerbation including 27.7% who received noninvasive ventilation and 45.5% who received invasive mechanical ventilation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Noninvasive ventilation failure was recorded in 13.7% from patients ventilated noninvasively. Hospital mortality was 7.4% for patients treated with noninvasive ventilation; 16.1% for those treated with invasive mechanical ventilation; and 22.5% for those who failed noninvasive ventilation. In the propensity-matched analysis, patients initially treated with noninvasive ventilation had a 41% lower risk of death compared with those treated with invasive mechanical ventilation (relative risk, 0.59; 95% CI, 0.36-0.97). Factors that were independently associated with noninvasive ventilation failure were Simplified Acute Physiology Score II (relative risk = 1.04 per point increase; 95% CI, 1.03-1.04) and the presence of cancer (2.29; 95% CI, 0.96-5.45).

CONCLUSIONS

Among critically ill adults with chronic obstructive pulmonary disease exacerbation, the receipt of noninvasive ventilation was associated with a lower risk of in-hospital mortality compared with that of invasive mechanical ventilation; noninvasive ventilation failure was associated with the worst outcomes. These results support the use of noninvasive ventilation as a first-line therapy in appropriately selected critically ill patients with chronic obstructive pulmonary disease while also highlighting the risks associated with noninvasive ventilation failure and the need to be cautious in the face of severe disease.

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.

Role of bronchoscopy during non invasive ventilation in hypercapnic respiratory failure

Introduction

Non invasive positive pressure ventilation (NIPPV) is the first line treatment for hypercapnic acute respiratory failure (ARF) secondary to COPD exacerbation in selected patients. Limited data exist supporting the use of fiberoptic bronchoscopy (FOB) during this clinical setting. The aim of this study is to assess the role of FOB during NIPPV in patients with decompensated COPD acute exacerbation.

Methods

This study is a randomized prospective case control pilot study carried out on 50 patients - admitted to critical care units at Alexandria University Hospital, Egypt - suffering from hypercapnic ARF secondary to COPD exacerbation with Kelly Matthay Score from 2 to 4. All patients received NIPPV. Patients were divided randomly into 2 equal groups: group I (cases) (25 patients) was subjected to additional intervention of early FOB during the first 6–12 h from admission while group II (control) (25 patients) received the conventional treatment and NIPPV only. Outcome parameters measured were changes in ABG data, duration of NIPPV, rate of its success, ICU stay and mortality as well as the safety of FOB and possible complications.

Results

No significant difference was detected between the 2 groups regarding the baseline characteristics. No serious complications happened from FOB, and Oxygen desaturation happened in 4/25 patients (16%), Tachycardia in 2/25 patients (8%). In group I, 23 patients (92%) were successfully weaned from NIPPV versus 16 patients (64%) in group II (p = 0.037). Total duration of NIPPV was 28.52 h in group I versus 56.25 h in group II (p = 0.001). Length of ICU stay was 4.84 days in group I versus 8.68 days in group II (p = 0.001). Only 1 patient died in group I versus 3 patients in group II (p = 0.609).

Conclusion

The early application of FOB during NIPPV in patients with ARF due to COPD exacerbation was shown to be safe. Significant improvement in the outcome of patients who underwent FOB was noticed in terms of improved ABG data, shorter duration of NIPPV, higher percentage of success and shorter ICU stay while no significant difference was detected in mortality.

Timing of noninvasive ventilation failure: causes, risk factors, and potential remedies

Background

Identifying the predictors of noninvasive ventilation (NIV) failure has attracted significant interest because of the strong link between failure and poor outcomes. However, very little attention has been paid to the timing of the failure. This narrative review focuses on the causes of NIV failure and risk factors and potential remedies for NIV failure, based on the timing factor.

Results

The possible causes of immediate failure (within minutes to <1 h) are a weak cough reflex, excessive secretions, hypercapnic encephalopathy, intolerance, agitation, and patient-ventilator asynchrony. The major potential interventions include chest physiotherapeutic techniques, early fiberoptic bronchoscopy, changing ventilator settings, and judicious sedation. The risk factors for early failure (within 1 to 48 h) may differ for hypercapnic and hypoxemic respiratory failure. However, most cases of early failure are due to poor arterial blood gas (ABGs) and an inability to promptly correct them, increased severity of illness, and the persistence of a high respiratory rate. Despite a satisfactory initial response, late failure (48 h after NIV) can occur and may be related to sleep disturbance.

Conclusions

Every clinician dealing with NIV should be aware of these risk factors and the predicted parameters of NIV failure that may change during the application of NIV. Close monitoring is required to detect early and late signs of deterioration, thereby preventing unavoidable delays in intubation.

Noninvasive mechanical ventilation with average volume assured pressure support (AVAPS) in patients with chronic obstructive pulmonary disease and hypercapnic encephalopathy

BACKGROUND

Non-invasive mechanical ventilation (NIV) in patients with acute respiratory failure has been traditionally determined based on clinical assessment and changes in blood gases, with NIV support pressures manually adjusted by an operator. Bilevel positive airway pressure-spontaneous/timed (BiPAP S/T) with average volume assured pressure support (AVAPS) uses a fixed tidal volume that automatically adjusts to a patient's needs. Our study assessed the use of BiPAP S/T with AVAPS in patients with chronic obstructive pulmonary disease (COPD) and hypercapnic encephalopathy as compared to BiPAP S/T alone, upon immediate arrival in the Emergency-ICU.

METHODS

We carried out a prospective interventional match-controlled study in Guayaquil, Ecuador. A total of 22 patients were analyzed. Eleven with COPD exacerbations and hypercapnic encephalopathy with a Glasgow Coma Scale (GCS) <10 and a pH of 7.25-7.35 were assigned to receive NIV via BiPAP S/T with AVAPS. Eleven patients were selected as paired controls for the initial group by physicians who were unfamiliar with our study, and these patients were administered BiPAP S/T. Arterial blood gases, GCS, vital signs, and ventilatory parameters were then measured and compared between the two groups.

RESULTS

We observed statistically significant differences in favor of the BiPAP S/T + AVAPS group in GCS (P = .00001), pCO(2) (P = .03) and maximum inspiratory positive airway pressure (IPAP) (P = .005), among others. However, no significant differences in terms of length of stay or days on NIV were observed.

CONCLUSIONS

BiPAP S/T with AVAPS facilitates rapid recovery of consciousness when compared to traditional BiPAP S/T in patients with chronic obstructive pulmonary disease and hypercapnic encephalopathy.

TRIAL REGISTRATION

Current Controlled Trials application ref is ISRCTN05135218.

What determines immediate use of invasive ventilation in patients with COPD?

BACKGROUND

The choice between non-invasive ventilation (NIV) and invasive ventilation in patients with an acute exacerbation of chronic obstructive pulmonary disease (AECOPD) may be irrational. The aim of this study was to examine those patient characteristics, and circumstances deemed important in the choice made between NIV and invasive ventilation in the intensive care unit (ICU).

METHODS

We first examined 95 admissions of AECOPD patients on nine ICUs and identified variables associated with invasive ventilation. Thereafter, a questionnaire was sent to ICU personnel to study the relative importance of different factors with a possible influence on the decision to use invasive ventilation at once.

RESULTS

Univariable analysis showed that increasing age [odds ratio (OR) 1.06 per year] and increasing body mass index (BMI) (OR 1.11 per kg/m(2) ) were associated with immediate invasive ventilation, while there was no such association with arterial blood gases or breath rate. BMI was the only factor that remained associated with immediate invasive ventilation in the multivariable analysis [OR 1.12 (95% confidence interval 1.03-1.23) kg/m(2) ]. Ranking of responses to the questionnaire showed that consciousness, respiratory symptoms and blood gases were powerful factors determining invasive ventilation, whereas high BMI and age were ranked low. Non-patient-related factors were also deemed important (physician in charge, presence of guidelines, ICU workload).

CONCLUSION

Factors other than those deemed most important in guidelines appear to have an inappropriate influence on the choice between NIV and immediate intubation in AECOPD in the ICU. These factors must be identified to further increase the appropriate use of NIV.

Trends in hospital admissions for acute exacerbation of COPD in Spain from 2006 to 2010

OBJECTIVE

We aim to analyze changes in incidence, comorbidity profile, length of hospital stay (LOHS), costs and in-hospital mortality (IHM) of patients hospitalized for acute exacerbations of chronic obstructive pulmonary disease (AE-COPD) over a 5-year study period in Spain.

METHODS

We selected all hospital admissions for AE-COPD between 2006 and 2010 from the National Hospital Discharge Database covering the entire population of Spain.

RESULTS

We identified a total of 215,835 patients. Overall crude incidence had decreased from 2.9 to 2.4 exacerbations of COPD per 10,000 inhabitants from 2006 to 2010 (p < 0.001). In 2006, 17.9% of patients had a Charlson Index >2 and in 2010, the prevalence had increased to 25.0% (p < 0.001). Regarding to treatment, we detected a significant increase in the use of non-invasive ventilation from 2.1% in 2006 to 5.3% in 2010 (p < 0.001). The median LOHS was 7 days in 2006 and it remained stable until 2010. During the period studied, the mean cost per patient increased from 3747 to 4129 Euros. Multivariate analysis showed that incidence of hospitalizations for AE-COPD and IHM had significantly decreased from 2006 to 2010.

CONCLUSIONS

The current study provides data indicating a decrease in incidence of hospital admissions for AE-COPD in Spain from 2006 to 2010 with concomitant reduction in IHM, despite increasing comorbidity during this period, with no variations in LOHS. The mean cost per patient has risen significantly.

Respiratory High-Dependency Care Units for the burden of acute respiratory failure

The burden of acute respiratory failure (ARF) has become one of the greatest epidemiological challenges for the modern health systems. Consistently, the imbalance between the increasing prevalence of acutely de-compensated respiratory diseases and the shortage of high-daily cost ICU beds has stimulated new health cost-effective solutions. Respiratory High-Dependency Care Units (RHDCU) provide a specialised environment for patients who require an "intermediate" level of care between the ICU and the ward, where non-invasive monitoring and assisted ventilation techniques are preferentially applied. Since they are dedicated to the management of "mono-organ" decompensations, treatment of ARF patients in RHDCU avoids the dangerous "under-assistance" in the ward and unnecessary "over-assistance" in ICU. RHDCUs provide a specialised quality of care for ARF with health resources optimisation and their spread throughout health systems has been driven by their high-level of expertise in non-invasive ventilation (NIV), weaning from invasive ventilation, tracheostomy care, and discharging planning for ventilator-dependent patients.

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.

Recent advances in the role of non-invasive ventilation in acute respiratory failure

Non-invasive positive pressure ventilation (NIPPV) is the technique of delivering mechanical ventilation without endotracheal intubation or tracheostomy. This is increasingly being utilised in both acute and chronic conditions. Strong evidence supports the use of NIPPV for acute respiratory failure (ARF) to prevent endotracheal intubation (ETI) and to facilitate extubation in patients with acute exacerbations of chronic obstructive pulmonary disease, to avoid ETI in acute cardiogenic pulmonary oedema (ACPO), and in immunocompromised patients. Weaker evidence supports the use of NIPPV for patients with ARF due to asthma exacerbations, with postoperative ARF, pneumonia and acute lung injury/acute respiratory distress syndrome. NIPPV should be applied under close monitoring for signs of treatment failure and, in such cases, ETI should be promptly available. A trained team, at an appropriate location, with careful patient selection and optimal choice of devices can optimise the outcome of NIPPV.

Hypercapnic encephalopathy syndrome: a new frontier for non-invasive ventilation?

According to the classical international guidelines, non-invasive ventilation is contraindicated in hypercapnic encephalopathy syndrome (HES) due to the poor compliance to ventilatory treatment of confused/agitated patients and the risk of aspirative pneumonia related to lack of airways protection. As a matter of fact, conventional mechanical ventilation has been recommended as "golden standard" in these patients. However, up to now there are not controlled data that have demonstrated in HES the advantage of conventional mechanical ventilation vs non-invasive ventilation. In fact, patients with altered mental status have been systematically excluded from the randomised and controlled trials performed with non-invasive ventilation in hypercapnic acute respiratory failure. Recent studies have clearly demonstrated that an initial cautious NPPV trial in selected HES patients may be attempt as long as there are no other contraindications and the technique is provided by experienced caregivers in a closely monitored setting where ETI is always readily available. The purpose of this review is to report the physiologic rationale, the clinical feasibility and the still open questions about the careful use of non-invasive ventilation in HES as first-line ventilatory strategy in place of conventional mechanical ventilation via endotracheal intubation.

A theoretical decision model to help inform advance directive discussions for patients with COPD

Background

Advance directives (AD) may promote preference-concordant care yet are absent in many patients with Chronic Obstructive Pulmonary Disease (COPD). In order to begin to inform AD discussions between clinicians and COPD patients, we constructed a decision tree to estimate the impact of alternative AD decisions on both quality and quantity of life (quality adjusted life years, QALYs).

Methods

Two aspects of the AD were considered, Do Not Intubate (DNI; i.e., no invasive mechanical ventilation) and Full Code (i.e., may use invasive mechanical ventilation). Model parameters were based on published estimates. Our model follows hypothetical patients with COPD to evaluate the effect of underlying COPD severity and of hypothetical patient-specific preferences (about long-term institutionalization and complications from invasive mechanical ventilation) on the recommended AD.

Results

Our theoretical model recommends endorsing the Full Code advance directive for patients who do not have strong preferences against having a potential complication from intubation (ETT complications) or being discharged to a long-term ECF. However, our model recommends endorsing the DNI advance directive for patients who do have strong preferences against having potential complications of intubation and are were willing to tradeoff substantial amounts of time alive to avoid ETT complications or permanent institutionalization. Our theoretical model also recommends endorsing the DNI advance directive for patients who have a higher probability of having complications from invasive ventilation (ETT).

Conclusions

Our model suggests that AD decisions are sensitive to patient preferences about long-term institutionalization and potential complications of therapy, particularly in patients with severe COPD. Future work will elicit actual patient preferences about complications of invasive mechanical ventilation, and incorporate our model into a clinical decision support to be used for actual COPD patients facing AD decisions.

Early fiberoptic bronchoscopy during non-invasive ventilation in patients with decompensated chronic obstructive pulmonary disease due to community-acquired-pneumonia

INTRODUCTION

Inefficient clearance of copious respiratory secretion is a cause of non-invasive positive pressure ventilation (NPPV) failure, especially in chronic respiratory patients with community-acquired-pneumonia (CAP) and impaired consciousness. We postulated that in such a clinical scenario, when intubation and conventional mechanical ventilation (CMV) are strongly recommended, the suction of secretions with fiberoptic bronchoscopy (FBO) may increase the chance of NPPV success. The objective of this pilot study was, firstly, to verify the safety and effectiveness of early FBO during NPPV and, secondly, to compare the hospital outcomes of this strategy versus a CMV-based strategy in patients with decompensated chronic obstructive pulmonary disease (COPD) due to CAP who are not appropriate candidates for NPPV because of inefficient mucous clearance and hypercapnic encephalopathy (HE).

METHODS

This is a 12-month prospective matched case-control study performed in one respiratory semi-intensive care unit (RSICU) with expertise in NPPV and in one intensive care unit (ICU). Fifteen acutely decompensated COPD patients with copious secretion retention and HE due to CAP undergoing NPPV in RSICU, and 15 controls (matched for arterial blood gases, acute physiology and chronic health evaluation score III, Kelly-Matthay scale, pneumonia extension and severity) receiving CMV in the ICU were studied.

RESULTS

Two hours of NPPV significantly improved arterial blood gases, Kelly and cough efficiency scores without FBO-related complications. NPPV avoided intubation in 12/15 patients (80%). Improvement in arterial blood gases was similar in the two groups, except for a greater PaO2/fraction of inspired oxygen ratio with CMV. The rates of overall and septic complications, and of tracheostomy were lower in the NPPV group (20%, 20%, and 0%) versus the CMV group (80%, 60%, and 40%; P < 0.05). Hospital mortality, duration of hospitalisation and duration of ventilation were similar in the two groups.

CONCLUSIONS

In patients with decompensated COPD due to CAP who are candidates for CMV because of HE and inability to clear copious secretions, NPPV with early therapeutic FBO performed by an experienced team is a feasible, safe and effective alternative strategy.

Long-term survival according to ventilation mode in acute respiratory failure secondary to chronic obstructive pulmonary disease: a multicenter, inception cohort study

PURPOSE

The aim of the study was to investigate 5-year survival stratified by mechanical ventilation modality in chronic obstructive pulmonary disease (COPD) patients treated in the ICU.

MATERIALS AND METHODS

Prospective, observational study of COPD patients with acute respiratory failure admitted to 9 multidisciplinary ICUs in Sweden. Characteristics on admission, including illness severity scores and the first blood gas, and survival were analyzed stratified by ventilation modality (noninvasive [NIV] vs invasive mechanical ventilation).

RESULTS

Ninety-three patients, mean age of 70.6 (SD, 9.6) years, were included. Sixteen patients were intubated immediately, whereas 77 were started on NIV. Patients who were started on NIV had a lower median body mass index (BMI) (21.9 vs 27.0; P < .01) and were younger compared to those who were intubated immediately (median age, 70 vs 74.5 years; P < .05). There were no differences in the initial blood gas results between the groups. Long-term survival was greater in patients with NIV (P < .05, log rank). The effect of NIV on survival remained after including age, Acute Physiology and Chronic Health Evaluation II score, and BMI in a multivariate Cox regression model (NIV hazard ratio, 0.44; 95% confidence interval, 0.21-0.92). Fifteen patients with failed NIV were intubated and mechanically ventilated. Long-term survival in patients with failed NIV was not significantly different from patients who were intubated immediately.

CONCLUSION

The short-term survival benefit of NIV previously found in randomized controlled trials still applies after 5 years of observation.

[Invasive and non-invasive ventilation in conflict with best palliative care in severe COPD]

This example of an 80-year-old patient with severe lung disease and respiratory failure demonstrates the difficult relationship between the patient's needs, physical symptoms, and social problems. This man decides after a prolonged and difficult in-patient treatment actively for home ventilation rather than die of respiratory failure. He opts for tracheostomy and invasive ventilation because he cannot handle non-invasive mask-ventilation sufficiently by himself. It requires professional communication and support to gain the acceptance of family and caregivers for home ventilation. A survey of existing data on end of life decision-making in end-stage lung disease is given.

Bibliography. Current world literature

This bibliography is compiled by clinicians from the journals listed at the end of this publication. It is based on literature entered into our database between 1 November 2007 and 31 October 2008 (articles are generally added to the database about two and a half months after publication). In addition, the bibliography contains every paper annotated by reviewers; these references were obtained from a variety of bibliographic databases and published between the beginning of the review period and the time of going to press. The bibliography has been grouped into topics that relate to the reviews in this issue.

[Non-invasive ventilation]

Non-invasive ventilation (NIV) is a technique that delivers mechanical ventilation avoiding side effects and complications associated with endotracheal intubation and invasive mechanical ventilation. This technique has proved to be effective in different types of respiratory failure. In this article, the authors revise the advantages and limitations of NIV, interfaces used and indications in acute and acute-on-chronic respiratory failure.

Treatment of respiratory failure in COPD

Patients with advanced COPD and acute or chronic respiratory failure are at high risk for death. Beyond pharmacological treatment, supplemental oxygen and mechanical ventilation are major treatment options. This review describes the physiological concepts underlying respiratory failure and its therapy, as well as important treatment outcomes. The rationale for the controlled supply of oxygen in acute hypoxic respiratory failure is undisputed. There is also a clear survival benefit from long-term oxygen therapy in patients with chronic hypoxia, while in mild, nocturnal, or exercise-induced hypoxemia such long-term benefits appear questionable. Furthermore, much evidence supports the use of non-invasive positive pressure ventilation in acute hypercapnic respiratory failure. It application reduces intubation and mortality rates, and the duration of intensive care unit or hospital stays, particularly in the presence of mild to moderate respiratory acidosis. COPD with chronic hypercapnic respiratory failure became a major indication for domiciliary mechanical ventilation, based on pathophysiological reasoning and on data regarding symptoms and quality of life. Still, however, its relevance for long-term survival has to be substantiated in prospective controlled studies. Such studies might preferentially recruit patients with repeated hypercapnic decompensation or a high risk for death, while ensuring effective ventilation and the patients’ adherence to therapy.

Iron lung versus mask ventilation in acute exacerbation of COPD: a randomised crossover study

OBJECTIVE

To compare iron lung (ILV) versus mask ventilation (NPPV) in the treatment of COPD patients with acute on chronic respiratory failure (ACRF).

DESIGN

Randomised multicentre study.

SETTING

Respiratory intermediate intensive care units very skilled in ILV.

PATIENTS AND METHODS

A total of 141 patients met the inclusion criteria and were assigned: 70 to ILV and 71 to NPPV. To establish the failure of the technique employed as first line major and minor criteria for endotracheal intubation (EI) were used. With major criteria EI was promptly established. With at least two minor criteria patients were shifted from one technique to the other.

RESULTS

On admission, PaO(2)/FiO(2), 198 (70) and 187 (64), PaCO(2), 90.5 (14.1) and 88.7 (13.5) mmHg, and pH 7.25 (0.04) and 7.25 (0.05), were similar for ILV and NPPV groups. When used as first line, the success of ILV (87%) was significantly greater (P = 0.01) than NPPV (68%), due to the number of patients that met minor criteria for EI; after the shift of the techniques; however, the need of EI and hospital mortality was similar in both groups. The total rate of success using both techniques increased from 77.3 to 87.9% (P = 0.028).

CONCLUSIONS

The sequential use of NPPV and ILV avoided EI in a large percentage of COPD patients with ACRF; ILV was more effective than NPPV on the basis of minor criteria for EI but after the crossover the need of EI on the basis of major criteria and mortality was similar in both groups of patients.