Lung Hyperinflation In Patients Research Articles

Small Airways Dysfunction and Lung Hyperinflation in Long COVID-19 Patients as Potential Mechanisms of Persistent Dyspnoea.

Reticulation, ground glass opacities and post-infection bronchiectasis are present three months following hospitalisation in patients recovering from SARS-CoV-2 infection and are associated with the severity of acute infection. However, scarce data exist on small airways impairment and lung hyperinflation in patients with long COVID-19. To evaluate small airways function and lung hyperinflation in previously hospitalised patients with long COVID-19 and their association with post-COVID-19 breathlessness. In total, 33 patients (mean ± SD, 53 ± 11 years) with long COVID-19 were recruited 149 ± 90 days following hospital discharge. Pulmonary function tests were performed and lung hyperinflation was defined as RV/TLC ≥ 40%. Small airways function was evaluated by measuring the closing volume (CV) and closing capacity (CC) using the single-breath nitrogen washout technique (SBN2W). CC was 115 ± 28% pred. and open capacity (OC) was 90 ± 19. CC was abnormal in 13 patients (39%), CV in 2 patients (6.1%) and OC in 9 patients (27%). Lung hyperinflation was present in 15 patients, whilst the mean mMRC score was 2.2 ± 1.0. Lung hyperinflation was associated with CC (r = 0.772, p = 0.001), OC (r = 0.895, p = 0.001) and mMRC (r = 0.444, p = 0.010). Long COVID-19 patients present with small airways dysfunction and lung hyperinflation, which is associated with persistent dyspnoea, following hospitalisation.

Impact of biologics on lung hyperinflation in patients with severe asthma

BackgroundIn asthma, inflammation affects both the proximal and distal airways and can cause significant hyperinflation, which is thought to be a major cause of dyspnea. MethodsThis is a retrospective observational study evaluating the effect of three months of treatment with different biologic drugs (benralizumab, dupilumab and omalizumab) on pulmonary hyperinflation in a cohort of patients with severe asthma already receiving regular triple inhaled therapy. Changes in RV, RV/TLC ratio, FRC and FRC/TLC ratio were the primary efficacy measures. Secondary outcomes included FEV1, FVC, FEV1/FVC ratio, IC, IC/TLC ratio, asthma control test, the percentage of eosinophils in the blood and fractional FENO. ResultsBenralizumab led to significant changes (p < 0.001) in RV, RV/TLC, FRC, and FRC/TLC. Dupilumab demonstrated a notable reduction in RV (p = 0.017) and RV/TLC (p = 0.002), but the decreases in FRC and FRC/TLC were merely numerical and not as pronounced as those induced by benralizumab. Omalizumab's positive impact on RV (p = 0.057) and RV/TLC (p = 0.085), as well as FRC (p = 0.202) and FRC/TLC (p = 0.096), was also predominantly numerical, with a tendency towards efficacy, albeit excluding the effect on FRC. Treatment with biologics resulted in improvements in all other lung function parameters assessed and a decrease in FENO levels. ConclusionThis study, although limited by small sample size, lack of a placebo control, and unbalanced group sizes, suggests that biological agents are effective in reducing lung hyperinflation even after a relatively short treatment.

Lung Ultrasound Assessment of Lung Hyperinflation in Patients with Stable COPD: An Effective Diagnostic Tool.

To evaluate the degree of lung hyperinflation (LH) in patients with stable chronic obstructive pulmonary disease (COPD) by lung ultrasound score (LUS) and assess its value. We conducted a study of 149 patients with stable COPD and 100 healthy controls recruited by the Second Affiliated Hospital of Fujian Medical University. The pleural sliding displacement (PSD) was measured, the sliding of the pleura in different areas was observed, and LUS was calculated from both of them. The diaphragm excursion (DE), residual capacity (RV), total lung capacity (TLC), inspiratory capacity (IC) and functional residual capacity (FRC) were measured. We described the correlation between ultrasound indicators and pulmonary function indicators reflecting LH. Multiple linear regression analysis was used. The ROC curves of LUS and DE were drawn to evaluate their diagnostic efficacy, and De Long method was used for comparison. (1) The LUS of patients with stable COPD were positively correlated with RV, TLC, RV/TLC and FRC and negatively correlated with IC and IC/TLC (r1=0.72, r2=0.41, r3=0.72, r4=0.70, r5=-0.56, r6=-0.65, P < 0.001). The correlation was stronger than that between DE at maximal deep inspiration and the corresponding pulmonary function indices (r1=-0.41, r2=-0.26, r3=-0.40, r4=-0.43, r5=0.30, r6=0.37, P < 0.001). (2) Multiple linear regression analysis showed that LUS were significantly correlated with IC/TLC and RV/TLC. (3) With IC/TLC<25% and RV/TLC>60% as the diagnostic criterion of severe LH, the areas under the ROC curves of LUS and DE at maximal deep inspiration for diagnosing severe LH were 0.914 and 0.385, 0.845 and 0.543, respectively (P < 0.001). The lung ultrasound score is an important parameter for evaluating LH. LUS is better than DE at maximal deep inspiration for diagnosing severe LH and is expected to become an effective auxiliary tool for evaluating LH.

Efficacy of Nebulized Glycopyrrolate on Lung Hyperinflation in Patients with COPD.

IntroductionLung hyperinflation in chronic obstructive pulmonary disease (COPD) is associated with activity limitation, impaired cardiac output, and mortality. Several studies have demonstrated that long-acting muscarinic antagonists (LAMAs) delivered by dry powder inhalers can promote lung deflation; however, the potential of nebulized LAMAs on improving hyperinflation in COPD is currently unknown.MethodsThis single-center, randomized, double-blind, two-way crossover study (NCT04155047) evaluated the efficacy of a single dose of nebulized LAMA [glycopyrrolate (GLY) 25 µg] versus placebo in patients with COPD and lung hyperinflation. Patients with moderate-to-severe COPD and a residual volume (RV) ≥ 130% of predicted normal were included. The primary endpoint was changed from baseline in RV at 6 h post-treatment. Other endpoints included changes from baseline in spirometric and plethysmographic measures up to 6 h post-treatment.ResultsA total of 22 patients (mean pre-bronchodilator RV, 153.7% of predicted normal) were included. The primary objective of the study was not met; the placebo-adjusted least squares (LS) mean [95% confidence interval (CI) change from baseline in RV with GLY at 6 h post-treatment was − 0.323 l (− 0.711 to 0.066); p = 0.0987]. A post hoc evaluation of the primary analysis was conducted after excluding a single statistical outlier; substantial improvements in RV with GLY compared with placebo was observed after exclusion of this outlier [placebo-adjusted LS mean change from baseline (95% CI) in RV was − 0.446 l (− 0.741 to − 0.150)]. Improvements from baseline were also observed with GLY compared with placebo in spirometric and plethysmographic measures up to 6 h post-treatment. GLY was generally safe, and no new safety signals were detected.ConclusionsThis is the first study to evaluate the effect of nebulized GLY on lung deflation. Nebulized GLY resulted in marked improvements in RV up to 6 h post-treatment, compared with placebo. Improvements were also observed with GLY in spirometric and plethysmographic parameters of lung function.Trial RegistrationClinicalTrials.gov identifier, NCT04155047.Supplementary InformationThe online version contains supplementary material available at 10.1007/s41030-021-00166-5.

Proportion of Lung Hyperinflation In Patients With Persistent Asthma In Persahabatan Hospital Jakarta Using Multiple Breath N2-Washout

Background: In asthma, small airway dysfunction and inflammation may induce significant lung hyperinflation. The aim of the study is to discover the proportion of lung hyperinflation in patient with persistent asthma in Persahabatan Hospital Jakarta. &#x0D; Method: A cross sectional study with descriptive analysis was done in Asthma clinic Persahabatan Hospital from September-November 2016. Forty-five subjects were recruited consecutively. Interview, physical examination, chest x-ray (CXR), spirometry and multiple breath N2-washout (MBW) were performed. Lung hyperinflation was defined as a residual volume /total lung capacity (RV/TLC%) above the upper limit of normal.&#x0D; Results: The proportion of lung hyperinflation in patients with persistent asthma was 17,8% (8 of 45 subjects).&#x0D; Median RV in milliliter was 1230 (570-2860). Median functional residual capacity (FRC) in milliliter was 1730 (970-3990). Median TLC in milliliter was 3310 (2490-6350). Mean RV/TLC ratio was 36,39% (SD±8,86). Mean FRC/TLC ratio was 52,86% (SD ±6,85). There was a significant correlation between forced expiratory volume in 1 second (FEV1%) value with lung hyperinflation with the decline of FEV1 &lt;60% increased the risk of lung hyperinflation by 8,46 (95%CI=1,155-61,98; p=0,036). There were no significant correlation between age, gender, smoking habit, body mass index (BMI), ACT score, the severity of persistent asthma, duration of asthma, duration of steroid inhalation use, exacerbation history in the last 12-months and emphysematous in CXR with lung hyperinflation (p&gt;0,05). &#x0D; Conclusions: The proportion of lung hyperinflation in patient with persistent asthma in Persahabatan Hospital Jakarta is 17,8%. Lung hyperinflation in persistent asthma is associated with the degree of airway obstruction.

Expiratory Flow Limitation and Its Relation to Dyspnea and Lung Hyperinflation in Patients with Chronic Obstructive Pulmonary Disease: Analysis Using the Forced Expiratory Flow-Volume Curve and Critique

Background: Tidal expiratory flow limitation (tEFL) is defined as absence of increase in air flow during forced expiration compared to tidal breathing and is related to dyspnea at rest and minimal exertion in patients with chronic airflow limitation (CAL). Tidal EFL has not been expressed as a continuous variable (0% - 100%) in previous analyses. Objective: To relate the magnitude of tEFL to spirometric values and Modified Medical Research Council (MMRC) score and Asthma Control Test (ACT). Methods: Tidal EFL was computed as percent of the tidal volume (0% - 100%) spanned (intersected) by the forced expiratory-volume curve. Results: Of 353 patients screened, 192 (114 M, 78 F) patients (136 with COPD, 56 with asthma) had CAL. Overall characteristics: (mean ± SD) age 59 ± 11 years, BMI 28 ± 7, FVC (% pred) 85 ± 20, FEV1 (% pred) 66 ± 21, FEV1/FVC 55% ± 10%, RV (% pred) 147 ± 42. Tidal EFL in patients with tEFL was 53% ± 39%. Using univariate analysis, strongest correlations were between tEFL and FVC and between tEFL and RV in patients with BMI 2. In patients with nonreversible CAL, tEFL was positively associated with increasing MMRC, negatively with spirometric measurements, and positively with RV/TLC. In asthmatics, ACT scores were higher in patients with mean BMI ≥ 28 kg/m2 (p 40% (p Conclusions: Dyspnea is strongly associated with tEFL and lung function, particularly in patients with nonreversible CAL. Air trapping and BMI contribute to tEFL.

Regional lung deflation with increased airway volume underlies the functional response to bronchodilators in chronic obstructive pulmonary disease.

Bronchodilators, including long‐acting muscarinic antagonists (LAMAs), improve airflow limitation and lung hyperinflation in patients with chronic obstructive pulmonary disease (COPD). While bronchodilators increase airway caliber and deflate the lungs, little is known about the effects of the local interaction between airway dilation and lung deflation on functional improvements resulting from bronchodilator therapy. This study aimed to explore whether lung deflation with increased airway volume in the upper and lower lung regions would produce different physiological responses to LAMA therapy. Using the clinical data of 41 patients with COPD who underwent spirometry and inspiratory computed tomography (CT) before and 1 year after LAMA treatment, we measured the 1‐year change in the airway tree to lung volume percentage ratio (AWV%) for the right upper, middle, and lower lobes (RUL, RML, and RLL) and the left upper and lower lobes (LUL and LLL), and total airway count (TAC) identifiable on CT in relation to the forced expiratory volume in 1 s (FEV1). The results showed that LAMA treatment significantly increased the FEV1 and AWV% of the RUL, RML, RLL, LUL, and LLL. Increased AWV% in the RLL and LLL, but not in the RUL and LUL, was correlated with increased FEV1. In the multivariate analysis, the increased AWV% in the RLL was associated with the increased FEV1 independent of the change in TAC in the RLL after treatment. This is the first study to show that the physiological improvements after bronchodilator treatment in COPD could be mainly due to the combination of regional deflation and increased airway volume of the lower lobes.

The Effect of CPAP on Lung Hyperinflation in Patients With OSA

The Effect of CPAP on Lung Hyperinflation in Patients With OSA

Developing a New Marker of Dynamic Hyperinflation in Patients with Obstructive Airway Disease - an observational study

Tidal volume at peak exercise and vital capacity ratio (VTpeak/VC) and VTpeak/inspiratory capacity (IC) were used to differentiate lung expansion in subjects with normal health and chronic obstructive pulmonary disease (COPD) from that in subjects with restrictive ventilation. However, VC and IC variably change due to pseudorestriction of lung volumes. Thus, these variables are currently not recommended. In contrast, total lung capacity (TLC) does little change during exercise. The aims of the study investigated whether VTpeak/TLC is more significantly correlated with static air trapping and lung hyperinflation in patients with COPD than VTpeak/IC, VTpeak/FVC, and VTpeak/SVC (study 1), and developed a marker to replace dynamic IC maneuvers by evaluation of the relationship between end-expiratory lung volume (EELV) and VTpeak/TLC and identification of a cutoff value for VTpeak/TLC (study 2). One hundred adults with COPD (study 1) and 23 with COPD and 19 controls (study 2) were analyzed. Spirometry, lung volume, diffusing capacity, incremental cardiopulmonary exercise tests with dynamic IC maneuvers were compared between groups. An ROC curve was generated to identify a cut off value for VTpeak/TLC. In study 1, VTpeak/TLC was more significantly associated with airflow obstruction, static air trapping and hyperinflation. In study 2, VTpeak/TLC was highly correlated with EELV in the patients (r = −0.83), and VTpeak/TLC ≥ 0.27 predicted that 18% of the patients with static air trapping and hyperinflation can expand their VT equivalent to the controls. In conclusions, VTpeak/TLC was superior to other VTpeak/capacities. VTpeak/TLC may be a marker of dynamic hyperinflation in subjects with COPD, thereby avoiding the need for dynamic IC maneuvers. VTpeak/TLC < 0.27 identified approximately 82% of subjects with COPD who could not adequately expand their tidal volume. As most of our participants were male, further studies are required to elucidate whether the results of this study can be applied to female patients with COPD.

Indacaterol improves lung hyperinflation and physical activity in patients with moderate chronic obstructive pulmonary disease--a randomized, multicenter, double-blind, placebo-controlled study.

BackgroundIndacaterol is a long-acting beta-2 agonist for once-daily treatment of COPD. We evaluated the effects of indacaterol 150 μg on lung hyperinflation compared with placebo and open-label tiotropium 18 μg. We measured physical activity during treatment with indacaterol 150 μg and matched placebo.MethodsWe performed a randomized, three-period, cross-over study (21 days of treatment separated by two wash-out periods of 13 days) with indacaterol 150 μg or matching placebo and tiotropium 18 μg. Lung function was assessed by body plethysmography and spirometry. Physical activity was measured for one week by a multisensory armband at the end of both treatment periods with indacaterol/matched placebo. The primary endpoint was peak inspiratory capacity at the end of each treatment period.Results129 patients (mean age, 61 years; mean post-bronchodilator FEV1, 64%), were randomized and 110 patients completed the study. Peak inspiratory capacity was 0.22 L greater with Indacaterol at day 21 compared to placebo (p < 0.001). Similar results were observed for tiotropium. Both bronchodilators also significantly improved other parameters of lung hyperinflation compared with placebo. All parameters of physical activity were significantly increased during treatment with indacaterol versus placebo.ConclusionsIndacaterol 150 μg improved lung hyperinflation in patients with moderate COPD, which was associated with an increase of physical activity.Trial registrationClinicalTrials.gov registration number: NCT01012765.

Pathogenesis of hyperinflation in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a preventable and treatable lung disease characterized by airflow limitation that is not fully reversible. In a significant proportion of patients with COPD, reduced lung elastic recoil combined with expiratory flow limitation leads to lung hyperinflation during the course of the disease. Development of hyperinflation during the course of COPD is insidious. Dynamic hyperinflation is highly prevalent in the advanced stages of COPD, and new evidence suggests that it also occurs in many patients with mild disease, independently of the presence of resting hyperinflation. Hyperinflation is clinically relevant for patients with COPD mainly because it contributes to dyspnea, exercise intolerance, skeletal muscle limitations, morbidity, and reduced physical activity levels associated with the disease. Various pharmacological and nonpharmacological interventions have been shown to reduce hyperinflation and delay the onset of ventilatory limitation in patients with COPD. The aim of this review is to address the more recent literature regarding the pathogenesis, assessment, and management of both static and dynamic lung hyperinflation in patients with COPD. We also address the influence of biological sex and obesity and new developments in our understanding of hyperinflation in patients with mild COPD and its evolution during progression of the disease.

Longitudinal Lung Volume Changes in Patients with Chronic Obstructive Pulmonary Disease

The progression of lung hyperinflation in patients with chronic obstructive pulmonary disease (COPD) has not been studied in a long-term prospective cohort. We explored the longitudinal changes in lung volume compartments with the aim of identifying predictors of a rapid decline of the inspiratory capacity to total lung capacity ratio (IC/TLC). The study population comprised 324 patients with COPD who were recruited prospectively. Annual rates of changes in pulmonary function, including forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), total lung capacity (TLC), functional residual capacity (FRC), residual volume (RV), vital capacity (VC), IC, and IC/TLC, were estimated using the random coefficient models. The mean annual rates of changes in pre- and post-bronchodilator FEV1 were -23.0 mL/year (p < 0.001) and -26.5 mL/year (p = 0.004). The mean annual rates of changes in VC, IC, TLC, and IC/TLC were -33.7 mL/year (p = 0.007), -53.9 mL/year (p < 0.001), -43.7 mL/year (p = 0.012), and -0.65%/year (p = 0.001), respectively. RV, FRC, and RV/TLC did not change significantly during the study period. Multivariate logistic regression analysis showed that a high modified Medical Research Council (MMRC) dyspnea scale score, a high Charlson comorbidity index value, and low post-bronchodilator FEV1 were associated with rapid decline in IC/TLC. MMRC dyspnea scale, post-bronchodilator FEV1, and the Charlson comorbidity index at baseline were independent predictors of a rapid decline in IC/TLC.

CPAP Decreases Lung Hyperinflation in Patients With Stable COPD

Dynamic hyperinflation, caused by expiratory flow limitation, markedly increases resting end-expiratory lung volume (functional residual capacity) in many COPD patients. To determine the impact and duration of impact of CPAP on hyperinflation and airway resistance in patients with stable COPD. In a case series, 21 patients underwent CPAP at 8 cm H(2)O for 15 min, then whole-body plethysmography immediately after, and at 15 and 30 min after CPAP. The cohort's mean ± SD age was 70 ± 9 y, and the mean FEV(1) was 41 ± 8% of predicted. Residual volume, functional residual capacity, total lung capacity, the ratio of residual volume to total lung capacity, and airway resistance decreased after CPAP and did not significantly change at 15 min (P < .001), but returned to baseline at 30 min. In patients with severe to very severe stable COPD, CPAP reduces lung volumes and airway resistance for 15 min, but the lung volumes return to baseline by 30 min.

Aclidinium bromide improves exercise endurance and lung hyperinflation in patients with moderate to severe COPD

Static and dynamic lung hyperinflation are associated with exercise impairment and poor outcomes in COPD patients. Aclidinium bromide is a novel, long-acting inhaled muscarinic antagonist currently in development for COPD treatment. Patients with moderate to severe COPD (N = 181) were randomized to once-daily aclidinium 200 μg or placebo for 6 weeks. Constant work rate cycling exercises at 75% of peak work rate were performed at baseline, Day 1, Week 3, and Week 6. The primary efficacy measure was change in exercise endurance time (ET) from baseline to Week 6. Secondary outcomes included changes in trough forced expiratory volume in 1 s (FEV(1)), inspiratory capacity (IC), IC/total lung capacity (TLC), and functional residual capacity (FRC) from baseline to Day 1, Week 3, and Week 6. Borg dyspnea scores during exercise, locus of symptom limitation, and safety measures were assessed. Aclidinium significantly improved ET on Day 1 (P = 0.0002), and improvements were sustained through Week 3 (P = 0.0007) and Week 6 (P = 0.0042) vs placebo. Compared with placebo, aclidinium improved trough FEV(1), IC, and IC/TLC at Weeks 3 and 6 (P < 0.05 for all). Exertional dyspnea scores at isotime were reduced on Day 1, Week 3, and Week 6 for aclidinium vs placebo (P < 0.05). Furthermore, the likelihood of stopping exercise due to breathing discomfort was lower in the aclidinium group at study end (P = 0.0208) compared with placebo. No differences in safety outcomes were reported between treatments. Aclidinium significantly increased exercise tolerance, improved airflow obstruction and lung hyperinflation, and was safe and well tolerated. REGISTRATION OF TRIAL: This trial was registered with ClinicalTrials.gov (NCT00500318) under the name "A Study of Exercise Endurance and Lung Hyperinflation in Patients with Moderate to Severe COPD".

Lung Hyperinflation and Its Reversibility in Patients with Airway Obstruction of Varying Severity

ABSTRACTThe natural history of lung hyperinflation in patients with airway obstruction is unknown. In particular, little information exists about the extent of air trapping and its reversibility to bronchodilator therapy in those with mild airway obstruction. We completed a retrospective analysis of data from individuals with airway obstruction who attended our pulmonary function laboratory and had plethysmographic lung volume measurements pre- and post-bronchodilator (salbutamol). COPD was likely the predominant diagnosis but patients with asthma may have been included. We studied 2,265 subjects (61% male), age 65 ± 9 years (mean ± SD) with a post-bronchodilator FEV1/FVC <0.70. We examined relationships between indices of airway obstruction and lung hyperinflation, and measured responses to bronchodilation across subgroups stratified by GOLD criteria. In GOLD stage I, vital capacity (VC) and inspiratory capacity (IC) were in the normal range; pre-bronchodilator residual volume (RV), functional residual capacity (FRC) and specific airway resistance were increased to 135%, 119% and 250% of predicted, respectively. For the group as a whole, RV and FRC increased exponentially as FEV1 decreased, while VC and IC decreased linearly. Regardless of baseline FEV1, the most consistent improvement following bronchodilation was RV reduction, in terms of magnitude and responder rate. In conclusion, increases (above normal) in airway resistance and plethysmographic lung volumes were found in those with only minor airway obstruction. Indices of lung hyperinflation increased exponentially as airway obstruction worsened. Those with the greatest resting lung hyperinflation showed the largest bronchodilator-induced volume deflation effects. Reduced air trapping was the predominant response to acute bronchodilation across severity subgroups.

50: Lung Function after Single Lung Transplantation (SLTx): Emphysema Versus Pulmonary Fibrosis

Purpose: SLTx is advocated to optimize organ availability for endstage obstructive or fibrotic respiratory disease.Contra-lateral native lung hyperinflation in recipients with obstructive lung disease may limit functional improvements after SLTx. We hypothesized that recipients with fibrotic lung disease will achieve higher best FEV1 after SLTx than obstructive recipients. Methods and Materials: Single centre, retrospective review of recipients surviving more than 12 months after SLTx for fibrotic or obstructive disease was performed. Pre-transplant spirometry, total lung capacity (TLC) and residual volume (RV) were correlated with the best achieved FEV1 after SLTx. The best post-transplant FEV1 was compared between the fibrotic and obstructive recipients. Results: 57 SLTx recipients were included, 35 obstructive, median age 55yrs (range 37-64), 22 fibrotic, 57yrs (30-64). Post-SLTx survival was not different between the two groups 7.4 v 6.5 yrs respectively. Pre-transplant lung function showed significantly higher TLC (7.99 v 3.50 l, p 0.001Mann-WhitneyU test), RV (5.91 v 1.36 l, p 0.001) and lower FEV1 (0.66 v 1.59 l/s, p 0.001) in obstructive recipients compared with fibrotics. Post-SLTx, the maximal achieved FEV1 was significantly higher in fibrotics (2.38 v 1.83 l/s, p 0.0004). The best post-SLTx FEV1 was corrected for sex, height & age as % predicted FEV1 and showed higher values in the fibrotic group (72.8% v 57.3%, p 0.002). There was no correlation between pre-transplant % predicted TLC or RV and post-SLTx % predicted FEV1in obstructive recipients (r 0.11 p 0.6 Spearman). Conclusions: SLTx recipients for fibrotic lung disease achieve better maximal FEV1 than those with obstructive disease. Our data suggest that native lung hyperinflation in patients with obstructive disease may not be the only factor to account for this difference. Single lung transplantation should be the operation of choice in patients with fibrotic lung disease. The lower achieved lung function in obstructive disease is more complex than hyperinflation and requires further investigation.

Inspiratory fraction and exercise impairment in COPD patients GOLD stages II-III

The inspiratory-to-total lung capacity ratio or "inspiratory fraction" (inspiratory capacity(IC)/total lung capacity (TLC)) may be functionally more representative than traditional indices of resting airflow limitation and lung hyperinflation in patients with chronic obstructive pulmonary disease (COPD). In the present retrospective study, a comparison was made of the individual performance of post-bronchodilator IC, IC/TLC and forced expiratory volume in one second (FEV(1)) in predicting a severely reduced peak oxygen uptake (V'(O(2)); <60% predicted) in 44 COPD patients Global Initiative for Chronic Obstructive Lung Disease stages II-III (post-bronchodilator FEV(1) ranging from 31-79% pred). Patients with lower IC/TLC values (<or=0.28) showed increased lung volumes and reduced exercise capacity as compared with other subjects. Following a multiple linear regression analysis, only IC/TLC and FEV(1) remained as independent predictors of V'(O(2)) (r(2) = 0.33). A receiver operating characteristic (ROC) curve analysis revealed that an IC/TLC <or=0.28 had the highest specificity (89.6%), positive predictive value (80%) and overall accuracy (86.3%) in identifying patients with V'(O(2)) <60% pred. In addition, the area under the ROC curve tended to be higher for IC/TLC than IC. In conclusion, post-bronchodilator total lung capacity-corrected inspiratory fraction provides useful information in addition to forced expiratory volume in one second and inspiratory capacity, to estimate the likelihood of chronic obstructive pulmonary disease patients to present with severely reduced maximal exercise capacity.

Differential lung ventilation after single-lung transplantation for emphysema

Objective: To review outcome and cardiovascular and respiratory function after initiation of differential lung ventilation for acute severe native lung hyperinflation in patients who have had a single-lung transplant for end-stage emphysema. Design: Retrospective review. Setting: Cardiothoracic tertiary referral center. Participants: Thirteen patients who had differential lung ventilation for acute severe native lung hyperinflation, of a total of 132 patients who had a single-lung transplant for end-stage emphysema between 1988 and the end of 2000. Interventions: None. Measurements and Main Results: Thirteen patients had differential lung ventilation for acute severe native lung hyperinflation; 7 survived to 1 year after transplant. There was a highly significant (p = 0.0006) improvement in mean PaO2 from 8.23 (95% confidence interval [CI], 6.15 to 10.3) to 16.6 (95% CI, 12.84 to 20.45) 1 hour after start of differential lung ventilation. The average ratio of estimated dynamic compliance in the native lung compared with the transplanted (donor) lung was 2.69 (95% CI, 1.75 to 3.62). Conclusion: In addition to previous case reports, this series shows that differential lung ventilation is an appropriate treatment for acute severe native lung hyperinflation. A difference in estimated effective dynamic compliance of ≥2.69 between native and transplanted lung may require differential lung ventilation. Copyright 2002, Elsevier Science (USA). All rights reserved.

Hemodynamic effects of intermittent manual lung hyperinflation in patients with septic shock

Objective: The purposes of this study were to investigate the hemodynamic changes induced by intermittent manual lung hyperinflation (MHI) and to assess if these changes are adverse enough to warrant prohibition of MHI as a routine procedure in the care of patients with septic shock. Design: The study’s design was experimental prospective. Setting: The settings were university hospital intensive care units. Patients: Subjects included 13 consecutive mechanically ventilated patients with septic shock who met the inclusion criteria. Measurements And Results: Phasic MHI-related increments in mean inspiratory airway pressure were concordant to changes in mean pulmonary artery pressure (MPAP) (r2 = 0.67) with a 0.6 mm Hg rise in MPAP per cm H2O airway pressure. The magnitude of MPAP changes was not reflected in magnitude of stroke volume index (SVI) (r2 = 0.06). On average, MHI did not induce statistically significant hemodynamic changes and mean values returned to baseline level within 15 minutes. SVI during MHI increased slightly in 9 patients, from 37 ± 15 (mean ± SD) to 41 ± 17 mL/m2 (P <.05), and decreased in 4, from 60 ± 10 to 50 ± 14 mL/m2 (not significant). Patients with an increase in SVI had lower baseline values for SVI, cardiac index, and left ventricular stroke work index (P <.05) and higher values for systemic vascular resistance index compared with patients with a decrease in SVI (P <.05). Left ventricular stroke work index was higher in patients with a decrease in SVI than in patients with an increase in SVI (52 ± 9 vs 34 ± 8; P <.05). Tidal volume increased from 499 ± 176 mL before MHI to 587 ± 82 mL, 5 minutes after MHI (P <.05) with a return to baseline values within 15 minutes after the procedure. Conclusion: The hemodynamic effects of intermittent MHI in patients with septic shock are relatively small and insignificant and seem to be related to the cardiovascular state before the procedure. The risk of inducing hemodynamic changes with MHI should not be considered as a contraindication in patients with septic shock who are mechanically ventilated. (Heart Lung® 2000;29:356-66.)

Exercise and Cystic Fibrosis: A Review.

Cystic fibrosis (CF) results in chronic obstructive pulmonary disease with progressive increases in areas of the lung with poor gas exchange (dead space). The pulmonary response to exercise is characterized by a higher than expected minute ventilation (V̇E). In some patients the elevated V̇Eis inadequate to overcome the large dead space, resulting in decreases in arterial oxygen and/or increases in arterial carbon dioxide levels during exercise. Chronic lung hyperinflation in patients with severe disease limits the ability to increase tidal volume, and therefore V̇E, during exercise. Most patients can exercise without decreases in arterial oxygen and should be encouraged to participate in regular activity. Oxygen supplementation during exercise allows many patients with severe lung dysfunction to participate in some form of activity. Regular exercise has been shown to be of some benefit and should be encouraged on an individual basis in patients with CF.