Minute Ventilation During Spontaneous Breathing,High-Intensity Noninvasive Positive Pressure Ventilation and Intelligent Volume Assured Pressure Support in Hypercapnic COPD

Background: High-intensity noninvasive positive pressure ventilation (HI-NPPV) is an effective treatment option in patients with stable hypercapnic chronic obstructive pulmonary disease (COPD). However, the effect of HI-NPPV compared with spontaneous breathing (SB) on minute ventilation (MV) in patients receiving long-term treatment remains to be determined. This study compared MV during HI-NPPV and SB. In addition, the ability of intelligent volume assured pressure support (iVAPS) to increase MV to the same extent as HI-NPPV was determined. Methods: Daytime pneumotachographic measurements were performed during SB, HI-NPPV and iVAPS. Results: Twenty-seven stable hypercapnic COPD patients (mean FEV₁ 34 ± 15% predicted) who had been treated with HI-NPPV for a median of 22 months (interquartile range 8.5–84 months) were enrolled. Mean MV was 9.5 ± 1.7 L/min during SB and 12.1 ± 2.8 L/min during HI-NPPV, an increase of 2.5 L/min (95%?CI [1.5–3.6] p < 0.001), or 26%. MV during iVAPS was 11.7 ± 3.6 L/min, an increase of 1.8 L/min (95%CI [0.7–3.0], p = 0.003) compared with SB. There was no difference in MV between HI-NPPV and iVAPS (p = 0.25). Conclusion: Long-term HI-NPPV increased MV by an average of 26% compared with SB in stable hypercapnic COPD patients. A similar increase in MV was observed during use of iVAPS.     

A Randomised Crossover Trial Comparing Volume Assured and Pressure Preset Noninvasive Ventilation in Stable Hypercapnic COPD

ABSTRACT

Recent randomised controlled trials suggest non-invasive ventilation may offer benefit in the long-term management of ventilatory failure in stable COPD. The best mode of ventilation is unknown and newer volume assured modes may offer advantages by optimising ventilation overnight when treatment is delivered. This study compares volume assured with pressure preset non-invasive ventilation. Randomised crossover trial including twenty five subjects previously established on long-term non-invasive ventilation to manage COPD with chronic ventilatory failure. Two 8-week treatment periods of volume assured and pressure preset non-invasive ventilation. The primary outcomes were daytime arterial blood gas tensions and mean nocturnal oxygen saturation. Secondary outcomes included lung function, exercise capacity, mean nocturnal transcutaneous carbon dioxide, health status and compliance. No significant differences were seen in primary or secondary outcomes following 8 weeks of treatment when comparing volume assured and pressure preset ventilation. Primary outcomes assessed: mean (standard deviation) PaO₂ 7.8 (1.2) vs 8.1(1) kPa, PaCO₂ 6.7 (1.1) vs 6.3 (1.2) kPa and mean nocturnal oxygenation 90 (4) vs 91 (3)% volume assured versus pressure preset, respectively. Volume assured and pressure preset non-invasive ventilation appear equally effective in the long-term management of ventilatory failure associated with stable COPD.     

Update: Non-Invasive Positive Pressure Ventilation in Chronic Respiratory Failure Due to COPD

Long-term non-invasive positive pressure ventilation (NPPV) has widely been accepted to treat chronic hypercapnic respiratory failure arising from different etiologies. Although the survival benefits provided by long-term NPPV in individuals with restrictive thoracic disorders or stable, slowly-progressing neuromuscular disorders are overwhelming, the benefits provided by long-term NPPV in patients with chronic obstructive pulmonary disease (COPD) remain under question, due to a lack of convincing evidence in the literature. In addition, long-term NPPV reportedly failed in the classic trials to improve important physiological parameters such as arterial blood gases, which might serve as an explanation as to why long-term NPPV has not been shown to substantially impact on survival. However, high intensity NPPV (HI-NPPV) using controlled NPPV with the highest possible inspiratory pressures tolerated by the patient has recently been described as a new and promising approach that is well-tolerated and is also capable of improving important physiological parameters such as arterial blood gases and lung function. This clearly contrasts with the conventional approach of low-intensity NPPV (LI-NPPV) that uses considerably lower inspiratory pressures with assisted forms of NPPV. Importantly, HI-NPPV was very recently shown to be superior to LI-NPPV in terms of improved overnight blood gases, and was also better tolerated than LI-NPPV. Furthermore, HI-NPPV, but not LI-NPPV, improved dyspnea, lung function and disease-specific aspects of health-related quality of life. A recent study showed that long-term treatment with NPPV with increased ventilatory pressures that reduced hypercapnia was associated with significant and sustained improvements in overall mortality. Thus, long-term NPPV seems to offer important benefits in this patient group, but the treatment success might be dependent on effective ventilatory strategies.     

慢性阻塞性肺疾病患者长期家庭无创正压通气疗效观察

目的观察在重度慢性阻塞性肺疾病稳定期患者长期家庭无创正压通气（NPPV）治疗的疗效。方法慢性阻塞性肺疾病（COPD）合并慢性呼吸衰竭患者45例,随机分为治疗组20例和对照组25例,在病情的稳定期,治疗组给予长期家庭无创正压通气及常规治疗,对照组仅给予常规治疗。随访2～3年,观察两组治疗前后的每年平均急性加重次数、平均住院时间、平均住院费用、呼吸困难程度、血气指标及病死率的变化。结果两组患者的每年急性加重次数及病死率差异无统计学意义（P〉O．05）,住院时间、住院费用、血气指标中pH值均有显著差异沪〈0．05）,呼吸困难程度、PCO：有显著性差异（P〈0．01）。结论长期家庭无创正压通气治疗是重度慢性阻塞性肺疾病合并慢性呼吸衰竭稳定期患者有效的治疗手段。     

有创-无创序贯机械通气救治非COPD急性严重呼吸衰竭的疗效观察

目的探讨有创-无创序贯机械通气救治非COPD病因所致急性严重呼吸衰竭的临床效果及应用价值。方法选择非COPD病因所致急性严重呼吸衰竭患者20例为序贯通气组,先经口气管插管有创通气,根据病情在3~7 d内拔除气管插管改为无创正压通气;选择相似病情病例20例作为对照组,经口气管插管有创通气,以同步间歇强制通气＋压力支持通气方式撤机。观察两组病例的机械通气时间、呼吸机相关性肺炎（VAP）发生率、撤机成功率、住院死亡率、总住院时间等。结果序贯通气组VAP发生率、有创通气时间、总机械通气时间、总住院时间明显低于对照组（P〈0.05）。结论有创-无创序贯机械通气策略不仅可应用于COPD所致的重症呼吸衰竭,对非COPD病因所致急性严重呼吸衰竭的救治也具有一定优势。     

慢性阻塞性肺疾病患者晚期反复发生严重呼吸衰竭的机械通气治疗

总结对慢性阻塞性肺疾病合并严重呼吸衰竭患者反复多次气管插管进行机械通气的经验。方法回顾性分析因ＣＯＰＤ急性加重而机械通气３次以上的１５例患者的临床资料及随访结果。结论对晚期ＣＯＰＤ合并严重呼吸衰竭患者实施反复多次的机械通气可延长生存期。     

Why High-Intensity NPPV is Favourable to Low-Intensity NPPV: Clinical and Physiological Reasons

High-intensity non-invasive positive pressure ventilation (NPPV) was originally described for chronic hypercapnic chronic obstructive pulmonary disease (COPD) patients in 2009, and refers to a specific ventilatory approach whereby NPPV settings are aimed at achieving the lowest arterial partial pressure of carbon dioxide (PaCO₂) values possible. Thus, high-intensity NPPV requires ventilator settings to be increased in a stepwise approach to either an individually tolerated maximum, or to the levels necessary to achieve normocapnia. This differs from the classic approach to low-intensity NPPV, which comprises considerably lower ventilator settings and typically fails to lower elevated PaCO₂ values. The ongoing discussion about whether or not long-term NPPV should be used in chronic hypercapnic COPD patients is based on the observation that many studies in the last two decades have failed to provide evidence for this particular patient cohort. In addition, these trials preferably used low-intensity NPPV. There is now, however, increasing evidence to suggest that high-intensity NPPV is capable of improving important physiological parameters such as blood gases and lung function, as well as health-related quality of life. Moreover, this approach also produced positive outcomes following two recent randomized controlled trials, e.g., improved survival rates in stable COPD patients, and admission-free survival in patients with persisting hypercapnia following acute in-hospital NPPV to treat acute acidotic respiratory failure. As a consequence, the time has now come to evaluate the impact of long-term NPPV on both the physiological and clinical outcomes, with emphasis on the different approaches to NPPV. Therefore, the aim of the current review article is to elaborate on the clinical and physiological reasons for why high-intensity NPPV is favourable to low-intensity NPPV.     

序贯性机械通气抢救非COPD病因所致严重呼吸衰竭

目的探讨有创与无创序贯机械通气（简称序贯性机械通气）抢救非COPD病因所致严重呼吸衰竭的临床效果及应用价值。方法选择非COPD病因所致呼吸衰竭患者18例为非COPD组,COPD所致呼吸衰竭15例为COPD组。先经口气管插管正压通气,根据病情在3—7天内拔除气管插管改为无创正压通气。观察两组病例的血气分析指标、机械通气时间、呼吸机相关性肺炎发生例数、撤机成功例数、住院死亡例数等。结果非COPD组和COPD组治疗前基础情况匹配良好（P均〉0．05）。非COPD组有刨通气时间明显长于COPD组（P〈0．05）,总通气时间、撤机成功例数、住院死亡例数两组均无显著性差异（P〉0．05）,住院费用明显高于COPD组（P〈0．05）。结论序贯性机械通气策略对非COPD病因所致呼吸衰竭可能也具有一定优势。     

肥胖对慢性阻塞性肺疾病稳定期病人无创机械通气治疗效果的影响

目的 探讨肥胖对进行无创机械通气的稳定期COPD病人疗效的影响.方法 纳入80例满足COPD全球倡议(GOLD)D组标准的病人,根据BMI分为对照组与肥胖组,每组40例.2组病人均按GOLD关于D组COPD的诊疗建议进行药物治疗,无创正压通气治疗每天至少6～8h.观察时间为3个月.治疗前后分别检测2组病人的动脉血气指标...     

有创与无创序贯性机械通气治疗慢性阻塞性肺疾病所致严重 …

OBJECTIVE: To estimate the feasibility and the efficacy of early extubation and sequential non-invasive mechanical ventilation(MV) in COPD with exacerbated hypercapnic respiratory failure. METHODS: 22 intubated COPD cases with severe hypercapnic respiratory failure due to pulmonary infection (pneumonia or purulent bronchitis) were involved in the study. At the time pulmonary infection had been significantly controlled (resolution of fever and decrease in purulent sputum, radiographic infiltrations, and leukocytosis. We call the time as "Pulmonary Infection Control Window", PIC window) after the antibiotic and the comprehensive therapy, the early extubation was conducted and followed by non-invasive MV via facial mask immediately in 11 cases (study group). Other 11 COPD cases with similar clinical characteristics who continuously received invasive MV after PIC window were used as control group. RESULTS: The groups had similar clinical characteristics and gas exchange, initially and at the time of PIC window. For study group and control group, the duration of invasive MV was (7.1 +/- 2.9) vs (23.0 +/- 14.0) days, P < 0.01; the total duration of ventilatory support was (13 +/- 7) vs (23 +/- 14) days, P < 0.05; the incidence of VAP were 0/11 vs 6/11, P < 0.01; the duration of ICU stay was (13 +/- 7) vs (26 +/- 14) days, P < 0.05, respectively. CONCLUSIONS: In COPD patients requiring intubation and MV for pulmonary infection and hypercapnic respiratory failure, early extubation followed by non-invasive MV initiated at the point of PIC window may significantly decrease the invasive and total durations of ventilatory support, the risk of VAP, and the duration of ICU stay.     

Non-invasive Positive Airway Pressure in Obesity Hypoventilation Syndrome and Chronic Obstructive Pulmonary Disease: Present and Future Perspectives

Obesity hypoventilation syndrome (OHS) is a sleep disorder that has acquired great importance worldwide because of its prevalence and association with obesity leading to increased morbidity and mortality with reduced quality of life. The primary feature is insufficient sleep-related ventilation, resulting in abnormally elevated arterial carbon dioxide pressure (PaCO₂) during sleep and demonstration of daytime hypoventilation. There are three main mechanisms that can generate diurnal hypoventilation in obese patients: alteration of the respiratory mechanics secondary to obesity; central hypoventilation secondary to leptin resistance and sleep disorder with sleep hypoventilation and obstructive apnoeas, which can be potentially solved with the use of positive airway pressure: non-invasive ventilation (NIV) and continuous positive airway pressure (CPAP). There are no established guidelines for the treatment of OHS, and only a few randomised controlled trials have been published. In this review, we have gone over the role of positive airway pressure, in particular the mechanisms that produce improvement, ventilatory modes available, clinical applications, technical considerations and future research. In addition, we added a review on NIV efficacy in chronic obstructive pulmonary disease (COPD), both in acute respiratory failure due to exacerbation and mainly in stable setting where more controversy and scientific contributions are coming.     

有创后序贯无创机械通气治疗重度COPD呼吸衰竭患者疗效观察

目的探讨有刨与无创序贯机械通气在治疗COPD重症呼吸衰竭的效果。方法选择40例COPD呼吸衰竭患者，随机分为两组，20例为有刨与无创序贯治疗组，20例为对照组，常规有创通气，以PSV方式至撤机。观察有创通气时间、总机械通气时间，医院获得性肺炎，住院时间、治疗费用等的差异；结果序贯治疗组与对照组，有创通气时间分别是（8．03±1．68）d和（15．02±2．96）d，总机械通气时间分别是（11．38±3．25）d和（19．29±4．11）d，VAP发生例数分别是3例和17例，住院时间分别是（15．89±2．01）d和（26．21±1．57）d，治疗费用分别是（1．09±0．01）万元和（1．92±0．06）万元，两组间比较差异有显著差异性（P〈0．05）。结论对COPD重症呼吸衰竭病例，采用有创与无刨序贯机械通气治疗可降低有刨机械通气时间、减少VAP的发生，减少住院时间及住院费用。     

The Effects of Withdrawing Long-Term Nocturnal Non-Invasive Ventilation in COPD Patients

ABSTRACT

Patients with ventilatory failure due to chronic obstructive pulmonary disease (COPD) are increasingly managed with long-term non-invasive positive pressure ventilation (NIPPV) and this may improve survival. NIPPV can frequently be interrupted but there are few data detailing the short-term effects and none on the longer-term consequences of treatment withdrawal. Ten patients withdrew from NIPPV for 1 week and were randomised to restart NIPPV or to continued withdrawal for up to 6 months. Outcomes assessed included daytime blood gases, nocturnal ventilation, lung function, exercise capacity and health status. After 1 week of withdrawal PaO₂, PaCO₂, nocturnal oximetry, lung function and exercise capacity did not change, but mean nocturnal transcutaneous CO₂ (6.3 (1) vs. 7.6 (1.1) kPa p = 0.04) and daytime blood gas bicarbonate (30.3 (4.5) vs. 31.2 (3.9) mmol/L p = 0.04) rose. During a 6-month period of withdrawal of nocturnal NIPPV, daytime PaCO₂ (6 (1.1) vs. 7.5 (1.3) kPa p = 0.002) increased and health status (total St George's Respiratory Questionnaire score 55.5 (6.3) vs. 65.6 (10) p = 0.006) worsened. Three out of five patients met a priori criteria to restart NIPPV in the continued withdrawal group. Short interruptions to domiciliary NIPPV used to manage chronic ventilatory failure as a consequence of COPD do not cause a rapid clinical deterioration but nocturnal ventilation worsens and daytime bicarbonate levels increase following 1 week's cessation. Thereafter, daytime PaCO₂ rises and health status worsens, supporting the role of long-term NIPPV in the management of such patients.     

无创正压通气在肺性脑病的治疗价值及其局限性

目的　观察无创正压通气 (BIPAP)在肺性脑病中的治疗价值及其局限性。方法　 5 6例肺性脑病患者经 BIPAP通气治疗为治疗组 ,同期 5 6例常规方法治疗为对照组 ,比较两组治疗前后血气分析指标及临床改善情况。结果　治疗组经无创正压治疗后临床症状改善和血气分析指标恢复正常 ,与对照组比较差异有显著性 (P<0 .0 1)。结论　 BIPAP在肺性脑病治疗中疗效肯定。对有较严重的意识障碍和 (或 )严重感染、痰量多、粘稠且咳痰无力者 ,宜行有创通气。照组相比均有显著性差异 (P<0 .0 1)。见表 1、表 2。表 1　两组治疗前后临床症状改善比较组别例数 神志转清心率下降呼吸频率下降辅助呼吸肌动作减轻治疗组 5 6 5 0 5 0 5 0 5 0对照组 5 6 2 314 2 5 17　　注 :均 P<0 .0 13　讨　　论肺性脑病是一种病死率极高的常见病 ,降低其病死率除需有效的抗生素外 ,有赖于早期的有效的呼吸支持 ,虽然有创机械通气在 COPD并发肺性脑病中发挥着重要作用 ,但有创机械通气尚存在创伤大、人工气道管理困难、易出现机械通气相关肺损伤、肺感染及不易脱机等许多问题。因此 ,积极探索无创通气在 COPD并肺性脑病治疗中的价值有着极其重要意义。表 2　两组治疗前后血气分析结果比较 (X±s)组别 PH Pa O2 (k Pa) Pa CO2 (k Pa) Sa O2     

家庭无创正压机械通气联合康复锻炼对慢性阻塞性肺疾病患者呼吸肌肌力的影响

目的评估家庭无创正压机械通气联合康复锻炼对稳定期重度慢性阻塞性肺疾病（COPD）患者呼吸肌肌力的影响。方法将56例经住院治疗处于稳定期的重度COPD患者分为无创呼吸机＋呼吸操组（治疗组,n=26）和无创呼吸机组（对照组,n=30）。分别观察治疗前、治疗后2年两组患者的最大吸气压（MIP）、跨膈压（Pdi）、最大跨膈压（Pdimax）及Pdi/Pdimax、CO_2分压（PaCO_2）、肺功能、6min行走距离（6MWD）、病死率及再住院率等指标。结果两组年龄、性别、COPD病程、体质量指数、PaCO_2、PaO_2、MIP、Pdi、Pdimax及Pdi/Pdimax、第一秒用力呼气容积实测值与预计值的比值（FEV_1%）、第一秒用力呼气容积占用力肺活量比值（FEV_1/FVC%）、6MWD和每年住院次数均具有可比性（均P〉0.05）。2的年后治疗组MIP,Pdi,Pdimax及Pdi/Pdimax,6MWD,每年住院次数分别为（76±6）cmH_2O,（48±5）cmH_2O,（126±11）cmH_2O,（0.38±0.01）,（263±33）m和（2.1±0.9）次/年,与对照组[（72±5）cmH_2O,（45±4）cmH_2O,（116±8）cmH_2O,（0.39±0.02）,（244±26）m,（2.6±0.9）次/年]比较均具有统计学意义（均P〈0.05）。治疗组死亡1例（1/26）,对照组2例（2/30）,两组比较差异无统计学意义（χ~2=0.02,P〉0.05）。结论长期家庭无创正压机械通气联合呼吸操康复锻炼治疗可以有效提高稳定期重度COPD患者呼吸肌肌力及呼吸肌耐力,改善运动功能,从而达到更好的长期治疗效果。     

慢性阻塞性肺疾病长期机械通气患者T细胞亚群、补体及免疫球蛋白的变化

目的研究慢性阻塞性肺疾病(COPD)长期机械通气患者T细胞亚群、补体及免疫球蛋白的变化规律.方法选择2003年3月至2005年2月解放军总医院老年病房收治的COPD长期机械通气患者42例,同时选择COPD稳定期的老年患者34例作为对照组.入选患者均进行免疫球蛋白IgA、IgG、IgM,补体C3、C4,及CD4、CD8的测定,并计算出CD4/CD8比值.结果COPD长期机械通气组与对照组比较,IgA、IgG、IgM均增高,补体C3、C4均降低,CD4降低、CD8升高,CD4/CD8降低.经统计学处理,除补体C3无统计学差异(P＞0.05)外,其余各项指标均有显著差异(P＜0.05).结论COPD长期机械通气患者T细胞亚群、补体及免疫球蛋白均存在异常,呼吸机相关肺炎的发生可能与免疫功能异常有关.     

Intubation and mechanical ventilation for COPD: development of an instrument to elicit patient preferences.

BACKGROUND: Whether to simply provide palliative care or to intubate and use mechanical ventilation (MV) in a patient with severe COPD in acute respiratory failure is a difficult decision. The outcome of MV cannot be accurately predicted. Some patients cannot be weaned from the ventilator; those who are weaned often return to chronic severe respiratory disability. It is important that patients participate in this decision, but assistance is required. To address these issues, we developed and pilot-tested an aid to assist patients with MV decisions. METHODS: A scenario-based decision aid was developed consisting of an audiocassette and a booklet describing intubation and MV and its possible outcomes. We used a probability tradeoff technique to elicit the patients' preferences and a decisional conflict scale to evaluate satisfaction. RESULTS: With the assistance of the decision aid, all patients (10 men and 10 women) reached a decision. Two men and all 10 women declined MV. Mean decisional conflict was low (2.2 of a possible 5; SD, 0.9). At 1 year, only two patients (11%) had changed their decision. The agreement between physicians and patients was 65%; between next-of-kin and patients, there was uniform disagreement. CONCLUSION: With the decision aid, stable decisions were made with satisfaction and confidence. Proxy decisions were incongruent, especially when made by family members. The strong gender effect should be further investigated. We suggest that the COPD decision aid be further tested in a community clinical setting.     

无创正压通气治疗慢性阻塞性肺疾病合并Ⅱ型呼吸衰竭近期疗效观察

目的探讨无创正压机械通气(NIPPV)在慢性阻塞性肺疾病(COPD)急性发作期合并Ⅱ型呼吸衰竭中的应用价值。方法64例COPD急性发作期合并呼吸衰竭患者随机分为对照组和治疗组。对照组给予常规治疗;治疗组除常规治疗外,加用NIPPV,通气时间5~7 d。比较两组同期血气分析及临床症状变化。结果治疗组血气、心率、呼吸频率等较对照组明显改善(P<0.01)。结论应用NIPPV可明显改善COPD急性发作期患者症状,提高PaO2,降低PaCO2,值得推广应用。