Comparison of two methods for weaning patients with chronic obstructive pulmonary disease requiring mechanical ventilation for more than 15 days.

We designed a prospective multicenter randomized controlled study in three long-term weaning units (LWU) to evaluate which protocol, inspiratory pressure support ventilation (PSV) or spontaneous breathing trials (SB), is more effective in weaning patients with chronic obstructive pulmonary disease (COPD) requiring mechanical ventilation for more than 15 d. Fifty-two of 75 patients, failing an initial T-piece trial at admission, were randomly assigned to PSV or SB (26 in both groups). No significant difference was found in weaning success rate (73% versus 77% in the PSV and SB group, respectively), mortality rate (11.5% versus 7.6%), duration of ventilatory assistance (181 +/- 161 versus 130 +/- 106 h), LWU (33 +/- 12 versus 35 +/- 19 d), or total hospital stay. The results of these defined protocols were retrospectively compared with an "uncontrolled clinical practice" in weaning historical control patients. The overall 30-d weaning success rate was significantly greater (87% versus 70%) and the time spent under mechanical ventilation by survived and weaned patients was shorter in the patients in the study than in historical control patients (103 +/- 144 versus 170 +/- 127 h). The LWU and hospital stays were also significantly shorter (27 +/- 12 versus 38 +/- 18 and 38 +/- 17 versus 47 +/- 18 d). Spontaneous breathing trials and decreasing levels of PSV are equally effective in difficult-to-wean patients with COPD. The application of a well-defined protocol, independent of the mode used, may result in better outcomes than uncontrolled clinical practice.     

Effect of salmeterol on the ventilatory response to exercise in chronic obstructive pulmonary disease.

This study examined the effects of bronchodilator-induced reductions in lung hyperinflation on breathing pattern, ventilation and dyspnoea during exercise in chronic obstructive pulmonary disease (COPD). Quantitative tidal flow/volume loop analysis was used to evaluate abnormalities in dynamic ventilatory mechanics and their manipulation by a bronchodilator. In a randomised double-blind crossover study, 23 patients with COPD (mean +/- SEM forced expiratory volume in one second 42 +/- 3% of the predicted value) inhaled salmeterol 50 microg or placebo twice daily for 2 weeks each. After each treatment period, 2 h after dose, patients performed pulmonary function tests and symptom-limited cycle exercise at 75% of their maximal work-rate. After salmeterol versus placebo at rest, volume-corrected maximal expiratory flow rates increased by 175 +/- 52%, inspiratory capacity (IC) increased by 11 +/- 2% pred and functional residual capacity decreased by 11 +/- 3% pred. At a standardised time during exercise, salmeterol increased IC, tidal volume (VT), mean inspiratory and expiratory flows, ventilation, oxygen uptake (VO2) and carbon dioxide output. Salmeterol increased peak exercise endurance, VO2 and ventilation by 58 +/- 19, 8 +/- 3 and 12 +/- 3%, respectively. Improvements in peak VO2 correlated best with increases in peak VT; increases in peak VT and resting IC were interrelated. The reduction in dyspnoea ratings at a standardised time correlated with the increased VT. Mechanical factors play an important role in shaping the ventilatory response to exercise in chronic obstructive pulmonary disease. Bronchodilator-induced lung deflation reduced mechanical restriction, increased ventilatory capacity and decreased respiratory discomfort, thereby increasing exercise endurance.     

Health-related quality of life in patients with chronic respiratory failure after long-term mechanical ventilation

STUDY OBJECTIVES: This study was aimed at assessing health-related quality of life (HRQL) in patients with chronic respiratory failure (CRF) and long-term survival following prolonged intensive care mechanical ventilation. DESIGN: Observational cohort study. SETTING: Patients with CRF who had been transferred to our specialized weaning centre due to prolonged mechanical ventilation (>14 days) and weaning failure. PATIENTS AND PARTICIPANTS: Out of 87 long-term survivors (>6 months), 73 patients (mean age: 60.3+/-13.6 years, chronic obstructive pulmonary disease (COPD, 43%), thoraco-restrictive (21%) or neuromuscular disorders (15%), various chronic diseases (22%)) returned the MOS 36-Item Short-Form Health Status Survey (SF-36) and the St. George's respiratory questionnaire (SGRQ). MEASUREMENTS AND RESULTS: The total ventilation time was 38.7+/-45.9 days. The time between discharge from ICU and HRQL assessment was 31.0+/-22.2 months. Physical health was markedly reduced compared to general population norm, but mental health was mildly impaired. HRQL was comparable to patients with stable CRF receiving non-invasive ventilation who did not need prolonged invasive MV. In addition, general HRQL was better in patients with restrictive respiratory disease compared to patients with neuromuscular diseases (P<0.05). Physiological parameters such as blood gases or lung function parameters were not correlated to any HRQL measurements. CONCLUSIONS: In patients with CRF surviving prolonged ventilation on ICU, the presence of CRF itself is the major determinant of HRQL. Here, the underlying cause of CRF is the major factor which determines the degree of HRQL impairment with patients suffering from restrictive ventilatory disorders reporting the best HRQL when compared to patients with COPD or neuromuscular diseases. Despite severe physical handicaps due to CRF mental health is only mildly compromised.     

Noninvasive ventilation as a systematic extubation and weaning technique in acute-on-chronic respiratory failure: a prospective, randomized controlled study.

Prolonged duration of endotracheal mechanical ventilation (ETMV) is associated with an increased morbidity and mortality in intensive care unit (ICU) patients. The aim of this study was to assess the usefulness of noninvasive ventilation (NIV) as a systematic extubation and weaning technique to reduce the duration of ETMV in acute-on-chronic respiratory failure (ACRF). Among 53 consecutively intubated patients admitted for ACRF, we conducted a prospective, randomized controlled trial of weaning in 33 patients who failed a 2-h T-piece weaning trial (2 h-WT) although they met simple criteria for weaning. Conventional invasive pressure support ventilation (IPSV) was used as the control weaning technique in 16 patients (IPSV group), and NIV was applied immediately after extubation in 17 patients (NIV group). The two weaning groups were similar for type of chronic respiratory failure (CRF), pulmonary function data, age, Simplified Acute Physiology Score (SAPS II), and severity of ACRF on admission. The characteristics of the two groups were also similar at randomization. In the IPSV group, 12 of 16 patients (75%) were successfully weaned and extubated, versus 13 of 17 (76.5%) in the NIV group (p = NS). NIV like IPSV significantly and similarly improved gas exchange in relation to that achieved during 2 h-WT (p < 0.05). The duration of ETMV was significantly shorter in the NIV (4.56 +/- 1.85 d) than in the IPSV group (7.69 +/- 3.79 d) (p = 0. 004). NIV also reduced the mean period of daily ventilatory support, but increased the total duration of ventilatory support related to weaning (3.46 +/- 1.42 d, versus 11.54 +/- 5.24 d with NIV; p = 0. 0001). Most patients in the IPSV group developed complications related to ETMV and/or the weaning process, but the difference was not significant (nine of 16 versus six of 17). The durations of ICU and hospital stays and the 3-mo survival were similar in the two groups. In conclusion, NIV permits earlier removal of the endotracheal tube than with conventional IPSV, and reduces the duration of daily ventilatory support without increasing the risk of weaning failures. NIV should be considered as a new and useful systematic approach to weaning in patients with ACRF who are difficult to wean.     

自主呼吸试验在COPD机械通气患者撤机中的作用

目的评估自主呼吸试验（SBT）在COPD机械通气患者撤机过程中的作用。方法选择52例COPD机械通气撤机成功的患者,分为两组：S组24例,采用SBT方式撤机拔管;NS组28例,采用逐渐降低机械通气支持水平的方式撤机拔管。对比两组患者的拔管时间、住重症监护病房（ICU）时间、呼吸机相关性肺炎（VAP）发生率、48 h内再插管率以及住院病死率。结果 S组与NS组的拔出气管插管时间120 min和（300.01±65.23）min）、住ICU时间（9.50±4.20）d和（18.60±10.30）d、VAP发生率12.50%和28.57%,均有统计学差异（P〈0.05）,而48 h内再插管率20.83%和21.43%、ICU病死率16.67%和17.85%,无统计学差异（P〉0.05）。结论应用SBT法撤机比渐减机械通气支持水平的方法具有更早拔出气管插管、住ICU时间短的优点,而且降低了VAP的发生率。     

Effect of unplanned extubation on outcome of mechanical ventilation

Unplanned extubation is a major complication of translaryngeal intubation, but its impact on mortality, duration of mechanical ventilation (MV), length of intensive care unit (ICU) and hospital stay, and need for ongoing hospital care has not been adequately defined. We performed a case-control study in a tertiary-care medical ICU, comparing 75 patients with unplanned extubation and 150 controls matched for Acute Physiology and Chronic Health Evaluation II score, presence of comorbid conditions, age, indication for MV, and sex. Forty-two (56%) patients required reintubation after unplanned extubation (74% immediately, 86% within 12 h). Thirty-three (44%) unplanned extubations occurred during weaning trials, and 30% of these patients needed reintubation (failed unplanned extubation). In contrast, 76% of patients with unplanned extubation occurring during ventilatory support required reintubation. Although mortality was similar to that of controls (failed unplanned extubation 40%, versus control 31%, p > 0.2), patients with failed unplanned extubation had a significantly longer duration of MV (19 versus 11 d, p < 0.01), longer stay in the ICU (21 versus 14 d, p < 0.05), and longer hospital stay (30 versus 21 d, p < 0.01), and survivors were more likely to require chronic care (64% versus 24%, p < 0.001). Successfully tolerated unplanned extubation was associated with a reduction in time from beginning of weaning to extubation (0.9 versus 2.0 d, p = 0.06), but with no difference in overall duration of MV, mortality, discharge location, ICU, or hospital stay as compared with these measures for controls. We conclude that unplanned extubation is not associated with increased mortality when compared with that of matched controls, although it does result in prolonged MV, longer ICU and hospital stay, and increased need for chronic care. These effects are due exclusively to patients who fail to tolerate unplanned extubation. Although successfully tolerated unplanned extubation decreased the duration of weaning trials, it had no other measurable beneficial impact on outcome.     

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.     

The role of non-invasive home mechanical ventilation in patients with chronic obstructive pulmonary disease requiring prolonged weaning

Background and objective: Patients with COPD who require prolonged weaning from invasive mechanical ventilation show poor long‐term survival. Whether non‐invasive home mechanical ventilation (HMV) has a beneficial effect after prolonged weaning has not yet been clearly determined. Methods: Patients with COPD who required prolonged weaning and were admitted to a specialized weaning centre between January 2002 and February 2008 were enrolled in the study. Long‐term survival and prognostic factors, including the role of non‐invasive HMV, were evaluated. Results: Of 117 patients (87 men, 30 women; mean age 69.5 ± 9.5 years) included in the study, weaning from invasive ventilation was achieved in 82 patients (70.1%). Successful weaning was associated with better survival 1 year after discharge from hospital (hazard ratio (HR) 2.24, 95% CI: 1.16–4.31; P = 0.016). Among the 82 patients who were successfully weaned, non‐invasive HMV was initiated in 39 (47.6%) due to persistent chronic ventilatory failure. Initiation of HMV was associated with a higher rate of survival to 1 year as compared with patients who did not receive ventilatory support (84.2% vs 54.3%; HR 3.68, 95% CI: 1.43–9.43; P = 0.007). In addition, younger age and higher PaO₂, haemoglobin concentration and haematocrit at discharge were associated with better survival. In an adjusted multivariate analysis, initiation of non‐invasive HMV after successful weaning remained an independent prognostic factor for survival to 1 year (HR 3.63, 95% CI: 1.23–10.75; P = 0.019). Conclusions: These findings suggest that based on the potential for improvement in long‐term survival, non‐invasive HMV should be considered in patients with severe COPD and persistent chronic hypercapnic respiratory failure after prolonged weaning.     

Iron lung vs mask ventilation in the treatment of acute on chronic respiratory failure in COPD patients: a multicenter study.

STUDY OBJECTIVES: Evaluation of the effectiveness of negative-pressure ventilation (NPV) with the use of the iron lung vs noninvasive positive-pressure ventilation (NIPPV) in the treatment of COPD patients with acute on chronic respiratory failure. DESIGN: A retrospective case-control study. SETTING: Four Italian respiratory intermediate ICUs. PATIENTS: Of a total of 393 COPD patients admitted to the ICU in 1996, 53 pairs were treated with the iron lung (NPV group). Patients treated with NIPPV (NIPPV group) were matched according to mean (+/- SD) age (70.3 +/- 7.1 vs 70.3 +/- 6.9 years, respectively), sex, causes of acute respiratory failure (ARF), APACHE (acute physiology and chronic health evaluation) II score (22.4 +/- 5.3 vs 22.1 +/- 4.6, respectively), pH (7.26 +/- 0.05 vs 7.27 +/- 0.04, respectively), and PaCO(2) (88.1 +/- 11.5 vs 85.1 +/- 13.5 mm Hg, respectively) on admission to the ICU. The effectiveness of matching was 98.4%. RESULTS: Five patients from the NPV group (9.4%) and seven patients from the NIPPV group (13.2%) needed endotracheal intubation (EI). The treatment failure rate (ie, death and/or need of EI) was 20.7% in the NPV group and 24.5% in the NIPPV group (difference was not significant). The mean duration of mechanical ventilation (29.6 +/- 28.6 vs 62.3 +/- 35.7 h, respectively) and length of hospital stay (10.4 +/- 4.3 vs 15 +/- 5.2 d, respectively) among the 35 concordant surviving pairs were significantly lower in the NPV group than in the NIPPV group (p = 0.001 and p = 0.001, respectively). CONCLUSIONS: These data suggest that both ventilatory techniques are equally effective in avoiding EI and death in COPD patients with ARF. Prospective trials are needed to confirm these preliminary results.     

Short-term noninvasive pressure support ventilation prevents ICU admittance in patients with acute cardiogenic pulmonary edema

STUDY OBJECTIVES: Noninvasive ventilation, although effective as treatment for patients with acute cardiogenic pulmonary edema when prolonged for hours, is of limited use in the emergency department (ED). The aim of the study was to determine whether a short attempt at noninvasive pressure support ventilation avoids ICU admittance and to identify lack of response prediction variables. DESIGN: Prospective inception cohort study. SETTING: ED of a university hospital. PATIENTS: Fifty-eight consecutive patients with cardiogenic pulmonary edema who had been unresponsive to medical treatment and were admitted between January 1999 and December 2000. INTERVENTIONS: Pressure support ventilation was instituted through a full-face mask until the resolution of respiratory failure. A 15-min "weaning test" was performed to evaluate clinical stability. Responder patients were transferred to a medical ward. Nonresponding patients were intubated and were admitted to the ICU. MAIN OUTCOME MEASURES: The included optimal length of intervention, the avoidance of ICU admittance, the incidence of myocardial infarction, and predictive lack of response criteria. RESULTS: Patients completed the trial (mean [+/- SD] duration, 96 +/- 40 min). None of the responders (43 patients; 74%) was subsequently ventilated or was admitted to the ICU. Two new episodes of myocardial infarction were observed. Thirteen of 58 patients died. A mean arterial pressure of < 95 mm Hg (odds ratio [OR], 10.6; 95% confidence interval [CI], 1.8 to 60.8; p < 0.01) and COPD (OR, 9.4; 95% CI, 1.6 to 54.0; p < 0.05) at baseline predicted the lack of response to noninvasive ventilation. CONCLUSIONS: A short attempt at noninvasive ventilation is effective in preventing invasive assistance. A 15-min weaning test can identify patients who will not need further invasive ventilatory support. COPD and hypotension at baseline are negative predictive criteria.     

Minute ventilation recovery time: a predictor of extubation outcome

STUDY OBJECTIVES: To determine if minute ventilation (E) measured as a trend following the final weaning trial prior to extubation may identify patients ready for extubation and be useful as a predictive measure of extubation outcome. DESIGN: Prospective observational study. SETTING: Community hospital medical/surgical ICU. PATIENTS: Sixty-nine patients receiving mechanical ventilation enrolled in an ICU weaning protocol who underwent planned extubation during 6 months of prospective evaluation. The failed extubation group included patients reintubated within 7 days. Patients were excluded if they received ventilation by noninvasive mask, bilevel positive airway pressure, tracheostomy, or were self-extubated. INTERVENTIONS: Patients tolerating a spontaneous breathing trial (SBT) and ready for planned extubation were placed back on their pre-SBT ventilator settings for up to 25 min, during which respiratory parameters were recorded. Respiratory parameters (respiratory rate, tidal volume, E, rapid shallow breathing index [f/VT]) were obtained at three time points: baseline (pre-SBT), posttrial (immediate conclusion of SBT), and recovery (return to baseline). Patients were assumed to recover when E decreased to 110% of the predetermined baseline. MEASUREMENTS AND RESULTS: Fifty-nine patients were successfully extubated, and 10 patients required reintubation after 2.5 +/- 2.6 days (mean +/- SD). Both groups were similar in age, comorbid status, primary diagnosis, APACHE (acute physiology and chronic health evaluation) II score, mode of weaning, and SBT length (p > 0.1). Respiratory parameters measured were similar at all three time points studied (p > 0.1). E recovery time of successful extubations was significantly shorter than failed extubations (3.6 +/- 2.7 min vs 9.6 +/- 5.8 min, p < 0.011). Multiple logistic regression adjusted for age, sex, and severity of illness revealed that E recovery time was an independent predictor of extubation outcome (p < 0.01). The area under the receiver operating characteristic curve for E recovery time (0.85 +/- 0.07) was larger than that for baseline E, posttrial E, posttrial f/VT, or PaCO(2). CONCLUSIONS: E recovery time is an easy-to-measure parameter that may assist in determining respiratory reserve. Preliminary data demonstrates that it may be a useful adjunct in the decision to discontinue mechanical ventilation.     

In-hospital and 5-year mortality of patients treated in the ICU for acute exacerbation of COPD: a retrospective study

STUDY OBJECTIVES: The prognosis of patients with COPD requiring admission to the ICU is generally believed to be poor. There is a paucity of long-term survival data. We undertook a study to examine both the in-hospital and 5-year mortality rates and to identify the clinical predictors of these outcomes. DESIGN: We conducted a retrospective cohort study of 57 patients admitted to the ICU between January 1999 and December 2000 for acute respiratory failure attributable to COPD. RESULTS: The mean (+/-SD) age of the study population was 70 +/- 8 years. More than 90% of patients required intubation, and the mean duration of mechanical ventilation (MV) was 2.3 +/- 2.2 days. The in-hospital mortality rate for the entire cohort was 24.5%. The mortality rates at 6 months and 1, 3, and 5 years were 39.0%, 42.7%, 61.2%, and 75.9%, respectively, following admission to the ICU. The median survival time for all patients was 26 months. The mortality rate at 5 years was 69.6% for patients who were discharged alive from the hospital. Using multivariate analysis, hospital mortality correlated positively with age, previous history of MV, long-term use of oral corticosteroids, ICU admission albumin level, APACHE (acute physiology and chronic health evaluation) II score, and duration of hospitalization. No factors predictive of mortality at 5 years were identified. CONCLUSIONS: We support previous findings of good early survival and significant but acceptable long-term mortality rates in patients who have been admitted to the ICU for acute exacerbation of COPD. Increased age, previous history of MV, poor nutritional status, and higher APACHE II score on ICU admission could be identified as risk factors associated with increased mortality rates. Long-term survival of patients with COPD who required MV for an acute exacerbation of their disease cannot be predicted simply from data available at the time of intubation. Physicians should incorporate these factors in their decision-making process.     

无创通气在慢性阻塞性肺疾病患者撤机中的应用

目的：探讨无创通气应用于慢性阻塞性肺疾病（COPD）患者有创机械通气撤机中的作用。方法：62例cOPD合并呼吸衰竭应用有创通气后撤机拔管的患者，分为治疗组32例，对照组30例，治疗组在常规药物治疗基础上应用无创通气，对照组应用常规治疗（药物治疗＋吸氧）。观察两组的血气分析指标、再插管率、住院天数及住院病死率等。结果：治疗组给予无创通气后与对照组比较动脉血气PaO2明显上升（P〈0．05），PaCO2下降明显（P〈0．05），两组再插管率为9%和30％（P〈0．05），住院天数为（32±10）d和（38±15）d（P〈0．05），住院病死率为6．2％和23．3％（P〈0．05）。结论：撤机拔管后立即开始应用无创通气的患者再插管率下降，住院天数减少及病死率下降。     

Capnometric recirculation gas tonometry and weaning from mechanical ventilation

The aim of this study was to describe changes in regional intramucosal PCO(2) (Pr(CO(2)) measured with capnometric recirculation gas tonometry [CRGT]) in patients with acute respiratory failure, who proceed from mechanical ventilation to weaning. In addition, we compared the predictive power for the weaning outcome of CRGT measurements obtained during mechanical ventilation to the frequency/ tidal volume (f/VT) ratio. A total of 24 patients (31 weaning trials) were included in the study, but four of the 24 patients (17%) were excluded because of extubation failure. Of the remaining 27 weaning trials in 20 patients, 12 (44%) were unsuccessful. Changes observed in patients with weaning failure (increase in Pr(CO(2)) from 60.4 +/- 15.0 mm Hg in mechanical ventilation to 67.4 +/- 21.0 mm Hg, in weaning) were significantly different (p = 0.046) from those observed in patients with weaning success (fall in Pr(CO(2)) from 61.5 +/- 15.0 mm Hg in mechanical ventilation to 56.3 +/- 16.7 mm Hg in weaning). However, absolute values of Pr(CO(2)) were not significantly different between patients with weaning success and failure, neither during mechanical ventilation (success, 61.5 +/- 15.0 versus failure, 60.4 +/- 15.0 mm Hg, p = 0.848) nor during weaning (success, 56.3 +/- 16.7 versus failure, 67.4 +/- 21.0 mm Hg, p = 0.135). The best single predictor for weaning outcome was the f/VT ratio measured early during weaning (area under the curve: 0.844 +/- 0.081; adjusted odds ratio for threshold value 相似文献   

Effectiveness and safety of a protocolized mechanical ventilation and weaning strategy of COPD patients by respiratory therapists

Introduction

Prior researches have showed that weaning protocols may decrease the duration of mechanical ventilation. The effect of these protocols on chronic obstructive pulmonary disease (COPD) patients is unknown. The purpose of this study was to evaluate the impact of an extensive mechanical ventilation protocol including weaning applied by a respiratory therapist (RT) on the duration of mechanical ventilation and intensive care unit (ICU) stay in COPD patients.

Materials and methods

A novel mechanical ventilation protocol including weaning was developed and initiated for all intubated COPD patients by a respiratory therapist. Outcomes of patients treated using this protocol during a 6-month period were compared to those of patients treated by physicians without a protocol during the preceding 6 months.

Results

A total of 170 patients were enrolled. Extubation success was significantly higher (98% vs. 78%, P=0.014) and median durations of weaning, mechanical ventilation and ICU stay compared with time to event analysis were significantly shorter in the protocol based group (2 vs. 26 hours, log rank P<0.001, 3.1 vs. 5 days, log rank P<0.001 and 6 vs. 12 days, log rank P<0.001, respectively). Patients who were successfully extubated and patients in the protocol based group were more likely to have shorter ventilation duration [HR: 1.87, 95% confidence intervals (CI): 1.13-3.08, P=0.015 and HR: 2.08, 95% CI: 1.40-3.10, P<0.001 respectively].

Conclusions

In our center, a protocolized mechanical ventilation and weaning strategy improved weaning success and shortened the total duration of mechanical ventilation and ICU stay in COPD patients requiring mechanical ventilation.     

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.     

A multicenter randomized trial of computer-driven protocolized weaning from mechanical ventilation

RATIONALE AND OBJECTIVES: Duration of weaning from mechanical ventilation may be reduced by the use of a systematic approach. We assessed whether a closed-loop knowledge-based algorithm introduced in a ventilator to act as a computer-driven weaning protocol can improve patient outcomes as compared with usual care. METHODS AND MEASUREMENTS: We conducted a multicenter randomized controlled study with concealed allocation to compare usual care for weaning with computer-driven weaning. The computerized protocol included an automatic gradual reduction in pressure support, automatic performance of spontaneous breathing trials (SBT), and generation of an incentive message when an SBT was successfully passed. One hundred forty-four patients were enrolled before weaning initiation. They were randomly allocated to computer-driven weaning or to physician-controlled weaning according to local guidelines. Weaning duration until successful extubation and total duration of ventilation were the primary endpoints. MAIN RESULTS: Weaning duration was reduced in the computer-driven group from a median of 5 to 3 d (p=0.01) and total duration of mechanical ventilation from 12 to 7.5 d (p=0.003). Reintubation rate did not differ (23 vs. 16%, p=0.40). Computer-driven weaning also decreased median intensive care unit (ICU) stay duration from 15.5 to 12 d (p=0.02) and caused no adverse events. The amount of sedation did not differ between groups. In the usual care group, compliance to recommended modes and to SBT was estimated, respectively, at 96 and 51%. CONCLUSIONS: The specific computer-driven system used in this study can reduce mechanical ventilation duration and ICU length of stay, as compared with a physician-controlled weaning process.     

Reflex cough PEF as a predictor of successful extubation in neurological patients*

Objective:

To evaluate the use of reflex cough PEF as a predictor of successful extubation in neurological patients who were candidates for weaning from mechanical ventilation.

Methods:

This was a cross-sectional study of 135 patients receiving mechanical ventilation for more than 24 h in the ICU of Cristo Redentor Hospital, in the city of Porto Alegre, Brazil. Reflex cough PEF, the rapid shallow breathing index, MIP, and MEP were measured, as were ventilatory, hemodynamic, and clinical parameters.

Results:

The mean age of the patients was 47.8 ± 17 years. The extubation failure rate was 33.3%. A reflex cough PEF of &lt; 80 L/min showed a relative risk of 3.6 (95% CI: 2.0-6.7), and the final Glasgow Coma Scale score showed a relative risk of 0.64 (95% CI: 0.51-0.83). For every 1-point increase in a Glasgow Coma Scale score of 8, there was a 36% reduction in the risk of extubation failure.

Conclusions:

Reflex cough PEF and the Glasgow Coma Scale score are independent predictors of extubation failure in neurological patients admitted to the ICU.     

Role of inspiratory capacity on exercise tolerance in COPD patients with and without tidal expiratory flow limitation at rest.

Expiratory flow limitation promotes dynamic hyperinflation during exercise in chronic obstructive pulmonary disease (COPD) patients with a consequent reduction in inspiratory capacity (IC), limiting their exercise tolerance. Therefore, the exercise capacity of patients with tidal expiratory flow limitation (FL) at rest should depend on the magnitude of IC. The presented study was designed to evaluate the role of FL on the relationship between resting IC, other respiratory function variables and exercise performance in COPD patients. Fifty-two patients were included in the study. Negative expiratory pressure (NEP) uptake (VO2,max) were measured during an incremental symptom-limited cycle exercise. Twenty-nine patients were FL at rest. The IC was normal in all non-FL patients, while in most FL subjects it was decreased. Both WRmax and VO2,max were lower in FL patients (p<0.001, each). A close relationship of WRmax and O2,max to IC was found (r=0.73 and 0.75, respectively; p<0.0001, each). In the whole group, stepwise regression analysis selected IC and forced expiratory volume in one second (FEV1)/forced vital capacity (FVC) (% predicted) as the only significant contributors to exercise tolerance. Subgroup analysis showed that IC was the sole predictor in FL patients, and FEV1/FVC in non-FL patients. Detection of flow limitation provides useful information on the factors that influence exercise capacity in chronic obstructive pulmonary disease patients. Accordingly, in patients with flow limitation, inspiratory capacity appears as the best predictor of exercise tolerance, reflecting the presence of dynamic hyperinflation.