Lung function indices for predicting mortality in COPD

Chronic obstructive pulmonary disease (COPD) is characterised by high morbidity and mortality. It remains unknown which aspect of lung function carries the most prognostic information and if simple spirometry is sufficient. Survival was assessed in COPD outpatients whose data had been added prospectively to a clinical audit database from the point of first full lung function testing including spirometry, lung volumes, gas transfer and arterial blood gases. Variables univariately associated with survival were entered into a multivariate Cox proportional hazard model. 604 patients were included (mean±sd age 61.9±9.7 years; forced expiratory volume in 1 s 37±18.1% predicted; 62.9% males); 229 (37.9%) died during a median follow-up of 83 months. Median survival was 91.9 (95% CI 80.8–103) months with survival rates at 3 and 5 years 0.83 and 0.66, respectively. Carbon monoxide transfer factor % pred quartiles (best quartile (>51%): HR 0.33, 95% CI 0.172–0.639; and second quartile (51–37.3%): HR 0.52, 95% CI 0.322–0.825; versus lowest quartile (<27.9%)), age (HR 1.04, 95% CI 1.02–1.06) and arterial oxygen partial pressure (HR 0.85, 95% CI 0.77–0.94) were the only parameters independently associated with mortality. Measurement of gas transfer provides additional prognostic information compared to spirometry in patients under hospital follow-up and could be considered routinely

The use of cardiopulmonary exercise testing in identifying the presence of obstructive sleep apnea syndrome in patients with compatible symptomatology

© 2019 The aim of this study was to investigate the relationship between cardiopulmonary exercise testing (CPET) and the presence of obstructive sleep apnea syndrome (OSAS) in order to provide an innovative tool to identify patients with OSAS. A prospective nested case control design was adopted. A consecutive population of male volunteers referred to a Sleep Unit was subjected to nocturnal polysomnography, full lung function testing and maximal CPET. A stepwise linear discriminant function analysis (DFA) was applied to construct a model which could identify individuals with moderate-to-severe OSAS from healthy controls. The total of 30 volunteers formed the OSAS and 24 the non-OSAS groups. Demographic and somatometric parameters were similar between groups. Patients presented with lower Expiratory Reserve Volume (ERV: 106.7 ± 28.3 vs. 123.9 ± 22.1, p < 0.001), Leg Fatigue Borg scale (3.9 ± 1.1 vs. 6.1 ± 1.4, p < 0.001), VO 2peak (25.0 ± 5.9 vs. 32.9 ± 7.2 ml/kg −1 /min −1 , p < 0.001), peak breathing frequency (31.0 ± 5.8 vs. 35.5 ± 7.3 1/min −1 , p < 0.001) and peak heart rate (151.1 ± 17.7 vs. 171.2 ± 12.6 beats/min −1 , p < 0.001) compared to controls, but higher peak end-tidal CO 2 (P ET CO 2peak :38.6 ± 4.2 vs. 35.0 ± 4.9 mmHg, p = 0.043) and peak systolic (SBP:188.3 ± 21.9 vs. 173.1 ± 17.9 mmHg, p = 0.009) and diastolic (DBP: 91.3 ± 8.2 vs. 85.4 ± 8.2 mmHg, p = 0.011) blood pressure. Stepwise DFA indicated that ERV % of predicted (0.372), P ET CO 2peak (−0.376), SpO 2resting (0.0667), Leg Fatigue Borg scale (0.564), HR peak (0.530) and DBP peak (−0.543) could separate the two groups, with an overall predictive accuracy of 96.3%. Selected CPET parameters (ERV % of predicted , P ET CO 2peak , SpO 2resting , HR peak , DBP peak and Leg Fatigue Borg Scale ) are independently associated with OSAS presence and could discriminate patients with and without this disorder.Published versio

A Combined Pulmonary Function and Emphysema Score Prognostic Index for Staging in Chronic Obstructive Pulmonary Disease

Chronic Obstructive Pulmonary Disease (COPD) is characterized by high morbidity and mortality. Lung computed tomography parameters, individually or as part of a composite index, may provide more prognostic information than pulmonary function tests alone.To investigate the prognostic value of emphysema score and pulmonary artery measurements compared with lung function parameters in COPD and construct a prognostic index using a contingent staging approach.Predictors of mortality were assessed in COPD outpatients whose lung computed tomography, spirometry, lung volumes and gas transfer data were collected prospectively in a clinical database. Univariate and multivariate Cox proportional hazard analysis models with bootstrap techniques were used.169 patients were included (59.8% male, 61.1 years old; Forced Expiratory Volume in 1 second % predicted: 40.5±19.2). 20.1% died; mean survival was 115.4 months. Age (HR = 1.098, 95% Cl = 1.04-1.252) and emphysema score (HR = 1.034, 95% CI = 1.007-1.07) were the only independent predictors of mortality. Pulmonary artery dimensions were not associated with survival. An emphysema score of 55% was chosen as the optimal threshold and 30% and 65% as suboptimals. Where emphysema score was between 30% and 65% (intermediate risk) the optimal lung volume threshold, a functional residual capacity of 210% predicted, was applied. This contingent staging approach separated patients with an intermediate risk based on emphysema score alone into high risk (Functional Residual Capacity ≥210% predicted) or low risk (Functional Residual Capacity <210% predicted). This approach was more discriminatory for survival (HR = 3.123; 95% CI = 1.094-10.412) than either individual component alone.Although to an extent limited by the small sample size, this preliminary study indicates that the composite Emphysema score-Functional Residual Capacity index might provide a better separation of high and low risk patients with COPD, than other individual predictors alone

An evaluation of factors associated with completion and benefit from pulmonary rehabilitation in COPD

All rights reserved. Background: Pulmonary Rehabilitation (PR) is an important treatment for patients with chronic obstructive pulmonary disease (COPD) but it is not established whether any baseline parameter can predict response or compliance. Aim: To identify whether baseline measures can predict who will complete the programme and who will achieve a clinically significant benefit from a Minimum Clinical Important Difference (MCID) in terms of exercise capacity and health-related quality of life (HRQoL). Methods: Data were collected prospectively from patients with COPD at their baseline assessment for an outpatient PR programme in one of eight centres across London. ‘Completion’ was defined as attending at least 75% of the designated PR visits and return for the follow-up evaluation. The MCID for outcome measures was based on published data. Results: 787 outpatients with COPD (68.1±10.5 years old; 49.6% males) were included. Patients who completed PR (n=449, 57.1%) were significantly older with less severe airflow obstruction, lower anxiety and depression scores, less dyspnoea and better HRQoL. Only baseline CAT score (OR=0.925; 95% CI 0.879 to 0.974; p=0.003) was retained in multivariate analysis. Patients with the lowest baseline walking distance were most likely to achieve the MCID for exercise capacity. No baseline variable could independently predict achievement of an MCID in HRQoL. Conclusions: Patients with better HRQoL are more likely to complete PR while worse baseline exercise performance makes the achievement of a positive MCID in exercise capacity more likely. However, no baseline parameter could predict who would benefit the most in terms of HRQoL

Missed opportunities for tobacco use screening and brief cessation advice in South African primary health care: a cross-sectional study

BACKGROUND: Primary health care (PHC) settings offer opportunities for tobacco use screening and brief cessation advice, but data on such activities in South Africa are limited. The aim of this study was to determine the extent to which participants were screened for and advised against tobacco use during consultations. METHODS: This cross-sectional study involved 500 participants, 18 years and older, attended by doctors or PHC nurses. Using an exit-interview questionnaire, information was obtained on participants' tobacco use status, reason(s) for seeking medical care, whether participants had been screened for and advised about their tobacco use and patients' level of comfort about being asked about and advised to quit tobacco use. Main outcome measures included patients' self-reports on having been screened and advised about tobacco use during their current clinic visit and/or any other visit within the last year. Data analysis included the use of chi-square statistics, t-tests and multiple logistic regression analysis. RESULTS: Of the 500 participants, 14.9% were current smokers and 12.1% were smokeless tobacco users. Only 12.9% of the participants were screened for tobacco use during their current visit, indicating the vast majority were not screened. Among the 134 tobacco users, 11.9% reported being advised against tobacco use during the current visit and 35.1% during any other visit within the last year. Of the participants not screened, 88% indicated they would be 'very comfortable' with being screened. A pregnancy-related clinic visit was the single most significant predictor for being screened during the current clinic visit (OR = 4.59; 95%CI = 2.13-9.88). CONCLUSION: Opportunities for tobacco use screening and brief cessation advice were largely missed by clinicians. Incorporating tobacco use status into the clinical vital signs as is done for pregnant patients during antenatal care visits in South Africa has the potential to improve tobacco use screening rates and subsequent cessation