Home mechanical ventilation for chronic obstructive pulmonary disease: What next after the HOT‐HMV trial?

The benefits of acute non‐invasive ventilation to treat acidotic exacerbations of chronic obstructive pulmonary disease (COPD) are well‐established. Until recently, the evidence for home mechanical ventilation (HMV) to treat patients with stable COPD had been lacking. This has subsequently been addressed by the application of higher levels of pressure support combined with targeted management of chronic respiratory failure, which demonstrated a reduction in all‐cause mortality. Similarly, the previous trial of home oxygen therapy (HOT) and HMV delivered following an acute exacerbation failed to demonstrate an improvement in outcome. With the focus on patients with persistent hypercapnic respiratory failure in the recovery phase following a life‐threatening exacerbation combined with targeted reduction in carbon dioxide, HOT and HMV (HOT‐HMV) was shown to be clinically effective in reducing the time to readmission or death and cost effective in both the United Kingdom and United States healthcare systems. Future work will need to focus on promoting adherence to home ventilation and novel auto‐titrating ventilator modes to facilitate and optimize the set‐up of overnight ventilatory support in different target population such as COPD patients with obstructive sleep apnoea and COPD patients with episodic nocturnal hypoventilation.     

Non invasive ventilation in COPD

Non invasive ventilation refers to the technique of providing ventilatory support without a direct conduit to the airway. It is a promising new technique, which is particularly useful in patients with COPD. Patients with COPD are prone to develop acute exacerbations, which pushes them into acute respiratory failure. Under these circumstances, tracheal intubation and mechanical ventilation is associated with significant morbidity and mortality. A number of well conducted studies support the fact that non invasive positive pressure ventilation (NIPPV) in these circumstances reduces rates of intubation, mortality, complications and duration of hospital stay. The biggest advantage of these techniques is their simplicity, ease of implementation and improved patient comfort allowing them to retain important functions like speech, cough and swallowing. NIPPV should be instituted early in the course of acute respiratory failure due to COPD before irreversible fatigue sets in. The current thinking is that NIPPV rests the respiratory muscles allowing other therapies time to be effective. Facilities for NIPPV should be available in all hospitals admitting patients with respiratory failure. Patients with severe, stable COPD who are hypercapnic and are deteriorating despite maximal conventional treatment should definitely be offered a trial of NIPPV. In such patients NIPPV has been shown to improve quality of life, reverse blood gas abnormalities, improve exercise tolerance and reduce hospital admissions. Physicians must familiarize themselves with this promising new ventilatory technique.     

Treatment of severe exacerbation of chronic obstructive pulmonary disease with mask-applied continuous positive airway pressure

Abstract The efficacy of mask-applied continuous positive airway pressure (CPAP) in the treatment of patients with acute severe exacerbations of chronic obstructive pulmonary disease (COPD) was examined. Ten patients with severe exacerbation of COPD who had deteriorated during conventional therapy were treated with face-mask delivered CPAP (+5 cmH₂ O; Downs Vital signs Inc., New Jersey, USA) instead of tracheal intubation and mechanical ventilation. The patients that were selected required mental alertness, intact upper airway reflexes, the clinical signs of dynamic hyperinflation and a positive end-expiratory pressure auto-(PEEP) manifested as expiratory wheeze and grunting. Nine out of 10 patients responded promptly to mask-CPAP with less distress, better oxygenation, lower respiratory and pulse rates. There was no significant change in arterial carbon dioxide tension with mask-CPAP treatment. One patient deteriorated on mask-CPAP and required intubation and mechanical ventilation. Three patients died (none of these patients died during the acute period of exacerbation). It was concluded that Mask-CPAP may be an alternative to mechanical ventilation in the treatment of selected patients with severe hypercapnic exacerbations of COPD.     

Nichtinvasive Beatmung – gestern, heute und morgen

Noninvasive mechanical ventilation (NIV) is used to treat chronic ventilatory insufficiency (CVI) and acute respiratory failure (ARF). Various diseases cause CVI and here home mechanical ventilation (HMV) has become an important treatment option. Clinical improvements due to HMV have been shown for CVI due to restrictive disorders of the rib cage like kyphoscoliosis or posttuberculosis sequelae, with an increase of quality of life, walking distance and a decrease in pulmonary hypertension. Conversely, HMV in patients with COPD is controversial and should be limited to patients with severe hypercapnia, using effective inspiratory pressures which significantly reduce work of breathing. NIV is an important treatment of ARF. Based on the evidence, NIV should be used to prevent intubation in patients with hypercapnic ARF due to COPD exacerbations or acute cardiogenic pulmonary edema, and in immunocompromised patients, as well as to facilitate extubation in patients with COPD who require initial intubation. Weaker evidence supports consideration of NIV in hypoxemic ARF due to severe pneumonia, acute lung injury, or acute respiratory distress syndrome.     

慢性阻塞性肺疾病并发呼吸衰竭的治疗

慢性阻塞性肺疾病(COPD)是呼吸系统的常见病和多发病,呼吸衰竭是COPD致死的主要原因,积极治疗呼吸衰竭具有重大意义.本文对氧疗、呼吸兴奋剂、机械通气在COPD急性加重期和稳定期呼吸衰竭的治疗作用及相关进展进行综述.     

Noninvasive ventilation for critical care

Noninvasive ventilation (NIV), the provision of ventilatory assistance without an artificial airway, has emerged as an important ventilatory modality in critical care. This has been fueled by evidence demonstrating improved outcomes in patients with respiratory failure due to COPD exacerbations, acute cardiogenic pulmonary edema, or immunocompromised states, and when NIV is used to facilitate extubation in COPD patients with failed spontaneous breathing trials. Numerous other applications are supported by weaker evidence. A trial of NIV is justified in patients with acute respiratory failure due to asthma exacerbations and postoperative states, extubation failure, hypoxemic respiratory failure, or a do-not-intubate status. Patients must be carefully selected according to available guidelines and clinical judgment, taking into account risk factors for NIV failure. Patients begun on NIV should be monitored closely in an ICU or other suitable setting until adequately stabilized, paying attention not only to vital signs and gas exchange, but also to comfort and tolerance. Patients not having a favorable initial response to NIV should be considered for intubation without delay. NIV is currently used in only a select minority of patients with acute respiratory failure, but with technical advances and new evidence on its proper application, this role is likely to further expand.     

Management of acute exacerbations of COPD

Exacerbations of COPD are common and cause a considerable burden to the patient and the healthcare system. To optimize the hospital care of patients with exacerbations of COPD, clinicians should be aware of some key points: management of exacerbations is broadly based on clinical features and severity. Initial clinical evaluation is crucial to define those patients requiring hospital admission and those who could be managed as outpatients. In hospitalized patients, the appropriate level of care should be determined by the initial severity and response to initial medical treatment. Medical treatment should follow recent recommendations, including rest, titrated oxygen therapy, inhaled or nebulized short-acting bronchodilators (Beta2-agonists and anticholinergic agents), DVT prevention with LMWH, steroids in most severely ill patients, unless there are contraindications and antibiotics in the case of a clear bacterial infectious aetiology. Severe exacerbations may lead to acute hypercapnic respiratory failure. Unless contraindicated, non-invasive ventilation (NIV) should be the first line ventilatory support for these patients. NIV should be commenced early, before severe acidosis ensues, to avoid the need for endotracheal intubation and to reduce mortality and treatment failures. Several randomised controlled clinical trials support the use of NIV in the management of acute exacerbations of COPD, demonstrating a decreased need for mechanical ventilation and an improved survival. In most severe cases, NIV should be provided in ICU. Although it has been shown that for less severe patients (with pH values>7.30), NIV can be administered safely and effectively on general medical wards, a lead respiratory consultant and trained nurses are mandatory. Mechanical ventilation through an endotracheal tube should be considered when patients have contraindications to the use of NIV or fail to improve on NIV. The duration of mechanical ventilation should be shortened as much as possible by an early weaning process, including preventive post-extubation NIV in hypercapnic patients. hospital stay could be shortened by non-invasive treatments. Future exacerbations should be avoided by respiratory specialist management of the patients, including education, optimization of long-term medical treatment, vaccinations, nutritional support, and pulmonary rehabilitation.     

Acute exacerbation of COPD

The literature of acute exacerbation of chronic obstructive pulmonary disease (COPD) is fast expanding. This review focuses on several aspects of acute exacerbation of COPD (AECOPD) including epidemiology, diagnosis and management. COPD poses a major health and economic burden in the Asia‐Pacific region, as it does worldwide. Triggering factors of AECOPD include infectious (bacteria and viruses) and environmental (air pollution and meteorological effect) factors. Disruption in the dynamic balance between the ‘pathogens’ (viral and bacterial) and the normal bacterial communities that constitute the lung microbiome likely contributes to the risk of exacerbations. The diagnostic approach to AECOPD varies based on the clinical setting and severity of the exacerbation. After history and examination, a number of investigations may be useful, including oximetry, sputum culture, chest X‐ray and blood tests for inflammatory markers. Arterial blood gases should be considered in severe exacerbations, to characterize respiratory failure. Depending on the severity, the acute management of AECOPD involves use of bronchodilators, steroids, antibiotics, oxygen and noninvasive ventilation. Hospitalization may be required, for severe exacerbations. Nonpharmacological interventions including disease‐specific self‐management, pulmonary rehabilitation, early medical follow‐up, home visits by respiratory health workers, integrated programmes and telehealth‐assisted hospital at home have been studied during hospitalization and shortly after discharge in patients who have had a recent AECOPD. Pharmacological approaches to reducing risk of future exacerbations include long‐acting bronchodilators, inhaled steroids, mucolytics, vaccinations and long‐term macrolides. Further studies are needed to assess the cost‐effectiveness of these interventions in preventing COPD exacerbations.     

Controlled oxygen administration in acute respiratory failure in chronic obstructive pulmonary disease: A reappraisal

Controlled oxygen therapy may aggravate carbon dioxide retention during acute exacerbations of chronic obstructive pulmonary disease (COPD). Of 50 consecutive patients with COPD and acute respiratory failure, 13 required intubation because of carbon dioxide narcosis. With discriminant analysis of their arterial oxygen tension (PaO₂) and pH on admission, a diagram separated patients into those at high risk and those at low risk for carbon dioxide narcosis. This diagram was then used to predict carbon dioxide narcosis in 73 patients with COPD and acute respiratory failure who were treated with controlled oxygen. In 16 of these patients carbon dioxide narcosis developed. Thirteen (81 per cent) were predicted by the diagram to be at high risk for this complication. Only two (4 per cent) patients judged by the diagram to be at low risk for carbon dioxide narcosis required mechanical ventilation. Utilizing an oxygen tension (PO₂), carbon dioxide tension (PCO₂) diagram a patient's ventilatory response was compared to that of ambulatory patients with COPD. These data suggest that hypoxemia and acidosis are more discriminatory for “carbon dioxide narcosis” than hypercapnia.     

Evidence-based approach to acute exacerbations of COPD

Chronic obstructive pulmonary disease (COPD) is the fourth leading cause of death in the United States, and it accounts for approximately 500,000 hospitalizations for exacerbations each year. New definitions of acute COPD exacerbation have been suggested, but the one used by Anthonisen et al. is still widely accepted. It requires the presence of one or more of the following findings: increase in sputum purulence, increase in sputum volume, and worsening of dyspnea. Patients with COPD typically present with acute decompensation of their disease one to three times a year, and 3% to 16% of these will require hospital admission. Hospital mortality of these admissions ranges from 3% to 10% in severe COPD patients, and it is much higher for patients requiring ICU admission. The etiology of the exacerbations is mainly infectious (up to 80%). Other conditions such as heart failure, pulmonary embolism, nonpulmonary infections, and pneumothorax can mimic an acute exacerbation or possibly act as "triggers." Baseline chest radiography and arterial blood gas analysis during an exacerbation are recommended. Oxygen administration through a venturi mask seems to be appropriate and safe, and the oxygen saturation should be kept just above 90%. Either a short acting beta 2-agonist or an anticholinergic is the preferred bronchodilator agent. The choice between the two depends largely on potential undesirable side effects and the patient's coexistent conditions. Adding a second bronchodilator to the first one does not seem to offer much benefit. The evidence suggests similar benefit of MDIs when compared with nebulized treatment for bronchodilator delivery. If MDIs are to be used, spacer devices are recommended. Steroids do improve several outcomes during an acute COPD exacerbation, and a 10- to 14-day course seems appropriate. Antibiotic use has been shown to be beneficial, especially for patients with severe exacerbation. Changes in bacteria strains have been documented during exacerbations, and newer generations of antibiotics might offer a better response rate. There is no role for mucolytic agents or chest physiotherapy in the acute exacerbation setting. Noninvasive positive pressure ventilation might benefit a group of patients with rapid decline in respiratory function and gas exchange. It has the potential to decrease the need for intubation and invasive mechanical ventilation and possibly decrease in-hospital mortality.     

Pediatric acute asthma exacerbations: Evaluation and management from emergency department to intensive care unit

Objective: The goal of this report is to review available modalities for assessing and managing acute asthma exacerbations in pediatric patients, including some that are not included in current expert panel guidelines. While it is not our purpose to provide a comprehensive review of the National Asthma Education and Prevention Program (NAEPP) guidelines, we review NAEPP-recommended treatments to provide the full range of treatments available for managing exacerbations with an emphasis on the continuum of care between the ER and ICU. Data Sources: We searched PubMed using the following search terms in different combinations: asthma, children, pediatric, exacerbation, epidemiology, pathophysiology, guidelines, treatment, management, oxygen, albuterol, β₂-agonist, anticholinergic, theophylline, corticosteroid, magnesium, heliox, BiPAP, ventilation, mechanical ventilation, non-invasive mechanical ventilation and respiratory failure. We attempted to weigh the evidence using the hierarchy in which meta-analyses of randomized controlled trials (RCTs) provide the strongest evidence, followed by individual RCTs, followed by observational studies. We also reviewed the NAEPP and Global Initiative for Asthma expert panel guidelines. Results and conclusions: Asthma is the most common chronic disease of childhood, and acute exacerbations are a significant burden to patients and to public health. Optimal assessment and management of exacerbations, including appropriate escalation of interventions, are essential to minimize morbidity and prevent mortality. While inhaled albuterol and systemic corticosteroids are the mainstay of exacerbation management, escalation may include interventions discussed in this review.     

Noninvasive Positive Pressure Ventilation in Acute Respiratory Failure of Chronic Obstructive Pulmonary Disease

Noninvasive positive pressure ventilation (NPPV) has reemerged as an effective strategy for reducing morbidity and mortality associated with acute exacerbations of chronic obstructive pulmonary disease (COPD). During acute respiratory failure, dynamic hyperinflation, intrinsic PEEP, and increased airway resistance result in a mechanical workload that exceeds inspiratory muscle capacity. NPPV provides augmentation of alveolar ventilation and respiratory muscle rest. Observational, cohort, and, more recently, randomized controlled trials have demonstrated the ability of NPPV to decrease the need for endotracheal intubation and decrease complications and mortality. NPPV performs better in COPD patients without significant comorbid illness. It should be initiated during COPD exacerbations if arterial pH is less than 7.35 or if the patient is severely distressed. Pressure support ventilation (10–20 cmH₂O) via face mask is likely the optimal technique and, when successful, results in rapid clinical improvement. Accepted for publication: 17 October 1996     

Management of acute exacerbations in chronic obstructive pulmonary disease

An acute exacerbation of chronic obstructive pulmonary disease (COPD) is characterized by an acute worsening of symptoms accompanied by lung infection. In severe cases, an acute exacerbation may cause respiratory failure and death. Successful management of acute exacerbation of COPD in either the inpatient or outpatient setting requires attention to a number of key issues. In this review, issues regarding the management of acute exacerbations of COPD are discussed. An inhaled beta-2 agonist along with the inhaled anticholinergic bronchodilator are recommended. Antibiotic therapy has been demonstrated to improve clinical recovery and physical outcomes. It should be directed against the most commonly occurring pathogens and, in more severe cases, coverage against Gram-negative bacteria is considered. Short course of systemic steroids does provide benefit in hospitalized patients. Supplemental oxygen is appropriate for all patients with hypoxemia. Ventilatory support treatment may be necessary, noninvasive ventilatory assistance being preferable early in the course of the acute episode. In a high number of cases, endotracheal intubation may be avoided. Promoting smoking cessation and the use of influenzae and pneumococcal vaccination may help decrease frequency of episodes of these exacerbations.     

无创正压通气治疗AECOPD合并呼吸衰竭的疗效观察

目的探讨无创正压通气（NIPPV）治疗慢性阻塞性肺病急性加重期（AECOPD）合并呼吸衰竭的临床效果。方法观察26例NIPPV治疗AECOPD合并呼吸衰竭患者的血气指标变化（PH、PaO2、PaCO2）,住院病程,气管插管率和病死率,并同以往未使用NIPPV治疗30例AECOPD合并呼吸衰竭病例进行比较。结果26例NIPPV治疗后2h、48h血气指标明显改善,住院病程缩短,气管插管率和病死率明显降低,同非NIPPV治疗的对照组比较差异有显著性。结论NIPPV是治疗AECOPD合并呼吸衰竭的一种有效方法,早期应用可阻止病情进一步加重,避免有创机械通气,缩短病程。     

Physiologic factors predisposing to chronic respiratory failure

V(A)/Q mismatching and load/capacity imbalance are the major physiologic determinants of chronic respiratory failure. The former underlies lung failure and the consequent development of hypoxemia. The latter causes chronic ventilatory failure and hypercapnia. This is the consequence of an inefficient breathing pattern with lower VT and higher respiratory rate, probably due to the "wise choice" of preventing excessive inspiratory effort and eventually respiratory muscle fatigue. In many disorders, V(A)/Q mismatching and the load/capacity imbalance coexist, particularly in COPD, where the interplay between the two pathophysiologically represents the advanced stage of the disease. In other disorders, one of the two mechanisms prevails; for example, V(A)/Q mismatching in pure lung diseases, and chest wall mechanics in thoracic disorders. This has important therapeutic implications because oxygen administration can relieve hypoxemia, whereas mechanical ventilation can prevent excessive hypercapnia and respiratory acidosis. Although the role of oxygen therapy is well established, the role of chronic mechanical ventilation is still a matter of debate, particularly in COPD. A major task for future research is to achieve the best possible understanding of the pathophysiologic factors predisposing to chronic ventilatory failure, to prevent the progression of the respiratory diseases to the stage when chronic respiratory failure eventually develops.     

COPD-Exazerbation und Intensivtherapie

Chronic obstructive pulmonary disease (COPD) is regarding prevalence, morbidity and mortality one of the most important disorders in medicine. Severe COPD exacerbation may cause admission to the intensive care unit (ICU). COPD exacerbation is defined as an increase of symptoms that goes beyond usual day-to-day variation and that necessitates a change in drug therapy. The in-hospital mortality of COPD patients with severe exacerbations lies between 3–10%. By admission to an ICU, mortality rises to 40% and above. Besides inhalation with bronchodilators, systemic steroids play a major role in COPD exacerbation therapy. Therapy with systemic steroids should not exceed 10–14 days. Antibiotics have a role if bacterial infection is probable. Macrolides should be used with caution, because up to 40% of Streptococcus pneumoniae spp. show resistance. Beside drug therapy, physiotherapy may have an impact on COPD exacerbation outcome, although prospective and randomized trials are missing. Patients with severe exacerbations may need temporary non-invasive or invasive ventilation. There is a clear priority for non-invasive ventilation. This article focuses on diagnosis and therapy of exacerbated COPD patients including ventilatory support.     

无创通气治疗慢性阻塞性肺部疾病轻中度呼吸衰竭疗效观察

目的探讨BiPAP经鼻罩或口鼻罩正压通气,对COPD轻中度呼吸衰竭早期无创通气的应用价值。方法将36例患者随机分为治疗组和对照组,两组各为18例。治疗组给予常规治疗加BiPAP通气,对照组单予常规治疗。在治疗前和治疗后2h及10h分别检测血气、呼吸频率(RR)和心率(HR),出院时统计插管率、病死率和住院天数。结果两组病人在治疗10h后PH、PaCO2、PaO2、RR和HR均得到明显改善(P<0.01),治疗组在治疗2h后PaCO2、RR和HR改善优于对照组(P<0.01)。两组需要插管机械通气分别为3例(16.3%)和7例(38.9%),差异无统计学意义(P>0.05)。治疗组死亡率2例(11.1%),对照组5例(27.8%),无统计学意义(P>0.05)。两组住院天数分别为(21±12)d和(32±19)d(P<0.05)。结论早期使用无创通气治疗能较快地改善COPD轻中度急性发作的通气功能,缩短住院天数。     

Clinical course and outcomes of COVID-19 patients with chronic obstructive pulmonary disease: A retrospective observational study in Wuhan,China

Information about coronavirus disease 2019 (COVID-19) patients with pre-existing chronic obstructive pulmonary disease (COPD) is still lacking. The aim of this study is to describe the clinical course and the outcome of COVID-19 patients with comorbid COPD.This retrospective study was performed at Wuhan Huoshenshan Hospital in China. Patients with a clear diagnosis of COVID-19 who had comorbid COPD (N = 78) were identified. COVID-19 patients without COPD were randomly selected and matched by age and sex to those with COPD. Clinical data were analyzed and compared between the two groups. The composite outcome was the onset of intensive care unit admission, use of mechanical ventilation, or death during hospitalization. Multivariable Cox regression analyses controlling for comorbidities were performed to explore the relationship between comorbid COPD and clinical outcome of COVID-19.Compared to age- and sex-matched COVID-19 patients without pre-existing COPD, patients with pre-existing COPD were more likely to present with dyspnea, necessitate expectorants, sedatives, and mechanical ventilation, suggesting the existence of acute exacerbations of COPD (AECOPD). Greater proportions of patients with COPD developed respiratory failure and yielded poor clinical outcomes. However, laboratory tests did not show severer infection, over-activated inflammatory responses, and multi-organ injury in patients with COPD. Kaplan–Meier analyses showed patients with COPD exhibited longer viral clearance time in the respiratory tract. Multifactor regression analysis showed COPD was independently correlated with poor clinical outcomes.COVID-19 patients with pre-existing COPD are more vulnerable to AECOPD and subsequent respiratory failure, which is the main culprit for unfavorable clinical outcomes. However, COPD pathophysiology itself is not associated with over-activated inflammation status seen in severe COVID-19.     

Predictors of outcome for patients with COPD requiring invasive mechanical ventilation

INTRODUCTION: Accurate outcomes data and predictors of outcomes are fundamental to the effective care of patients with COPD and in guiding them and their families through end-of-life decisions. DESIGN: We conducted a retrospective cohort study of 166 patients using prospectively gathered data in patients with COPD who required mechanical ventilation for acute respiratory failure of diverse etiologies. RESULTS: The in-hospital mortality rate for the entire cohort was 28% but fell to 12% for patients with a COPD exacerbation and without a comorbid illness. Univariate analysis showed a higher mortality rate among those patients who required > 72 h of mechanical ventilation (37% vs 16%; p < 0.01), those without previous episodes of mechanical ventilation (33% vs 11%; p < 0.01), and those with a failed extubation attempt (36% vs 7%; p = 0.0001). With multiple logistical regression, higher acute physiology score measured 6 h after the onset of mechanical ventilation, presence of malignancy, presence of APACHE (acute physiology and chronic health evaluation) II-associated comorbidity, and the need for mechanical ventilation > or = 72 h were independent predictors of poor outcome. CONCLUSIONS: We conclude that among variables available within the first 6 h of mechanical ventilation, the presence of comorbidity and a measure of the severity of the acute illness are predictors of in-hospital mortality among patients with COPD and acute respiratory failure. The occurrence of extubation failure or the need for mechanical ventilation beyond 72 h also portends a worse prognosis.     

Limitations of noninvasive mask ventilation in acute hypoxemic gas exchange disorders (COPD)

The benefit of noninvasive mask ventilation (NIMV) compared to mechanical ventilation after intubation is proven in patients with acute exacerbation of COPD. Contrary to this point the benefit is not clear in patients with acute gas exchange failure, such as in pneumonias. We tried to evaluate the efficiency of NIMV in this indication in a clinical case series. We treated 31 patients with acute gas exchange failure (pO2 52 +/- 11 Torr, APACHE II Score 20 +/- 7) with NIMV. In 18 patients (58%) blood gases improved. But during the further course 2 patients were intubated, 3 patients died. In 13 patients mask ventilation was stopped because of ineffectivity. 11 patients were intubated, 8 patients died. 3 patients were not intubated for ethical reasons. The success rate is about 20% lower than in patients with acute ventilatory insufficiency. NIMV can be used in patients with severe gas exchange failure. Until now, however, no data are available proving that the method offers significant advantages over intubation and mechanical ventilation.