ARTP statement on pulmonary function testing 2020.

The Association for Respiratory Technology & Physiology (ARTP) last produced a statement on the performance of lung function testing in 1994. At that time the focus was on a practical statement for people working in lung function laboratories. Since that time there have been many technological advances and alterations to best practice in the measurement and interpretation of lung function assessments. In light of these advances an update was warranted. ARTP, therefore, have provided within this document, where available, the most up-to-date and evidence-based recommendations for the most common lung function assessments performed in laboratories across the UK. These recommendations set out the requirements and considerations that need to be made in terms of environmental and patient factors that may influence both the performance and interpretation of lung function tests. They also incorporate procedures to ensure quality assured diagnostic investigations that include those associated with equipment, the healthcare professional conducting the assessments and the results achieved by the subject. Each section aims to outline the common parameters provided for each investigation, a brief principle behind the measurements (where applicable), and suggested acceptability and reproducibility criteria.

Lung clearance index in detection of post-transplant bronchiolitis obliterans syndrome.

BACKGROUND: Long-term outcomes after lung transplantation are often limited by the development of obliterative bronchiolitis (OB), which is clinically defined using spirometry as bronchiolitis obliterans syndrome (BOS). Lung clearance index (LCI), derived from multiple breath washout (MBW) testing, is a global measure of ventilation heterogeneity that has previously been shown to be a more sensitive measure of obstructive small airway diseases than spirometry. We aimed to assess the feasibility of LCI in adult lung transplant patients and to compare LCI to BOS grade. METHODS: 51 stable adult double-lung transplant recipients performed sulfur hexafluoride MBW in triplicate on a single occasion, using a closed-circuit Innocor device. BOS grades were derived from serial spirometry according to International Society for Heart and Lung Transplantation criteria and, where available, high-resolution computed tomography (HRCT) evidence of OB was recorded. RESULTS: LCI was successfully performed in 98% of patients. The within-visit coefficient of variation for repeat LCI measurements was 3.1%. Mean LCI increased significantly with BOS grades: no BOS (n=15), LCI 7.6; BOS-0p (n=16), LCI 8.3; BOS-1 (n=11), LCI 9.3; BOS-2-3 (n=9), LCI 13.2 (p<0.001). 27 patients had HRCT within 12 months. LCI in those with HRCT evidence of OB was higher than those without OB (11.1 versus 8.2, p=0.006). 47% patients displayed abnormal LCI (>7) despite a normal forced expiratory volume in 1 s (FEV1) (>80% of baseline). CONCLUSIONS: LCI measurement in lung transplant recipients is feasible and reproducible. LCI increased with increasing BOS grade. A significant proportion of this cohort had abnormal LCI with preserved FEV1, suggesting early subclinical small airway dysfunction, and supporting a role for MBW in the early identification of BOS.

Utility of plasma N-terminal brain natriuretic peptide as a marker of functional capacity in patients with chronic severe mitral regurgitation.

Plasma levels of N-terminal pro-brain natriuretic peptide (NT-pro-BNP) are elevated in severe mitral regurgitation, but their relation to functional capacity and cardiac remodeling is not well defined. We evaluated the role of NT-pro-BNP as a marker of functional capacity, symptoms, and cardiac remodeling in 38 patients with severe degenerative mitral regurgitation and preserved left ventricular ejection fraction. The NT-pro-BNP levels increased progressively with New York Heart Association (NYHA) functional class: NYHA class I (geometric mean [GM] 97.1 pg/ml), NYHA class II (GM 169.8 pg/ml), and NYHA III (GM 457.6 pg/ml; p = 0.015). The end-systolic volume index (r = 0.52, p = 0.001), end-diastolic volume index (r = 0.46, p = 0.003), left atrial volume index (r = 0.4, p = 0.01), regurgitant volume index (r = 0.38, p = 0.02), regurgitant fraction (r = 0.46, p = 0.003), and end-diastolic sphericity index (r = 0.56, p <0.001) all correlated significantly with NT-pro-BNP. The NT-pro-BNP levels correlated significantly with the exercise parameters: maximum oxygen uptake (r = -0.6, p <0.001), exercise time (r = -0.52, p <0.001), and oxygen pulse (r = -0.57, p <0.001). In contrast, only weak correlations were obtained between the exercise and echocardiographic variables. NT-pro-BNP was a strong independent predictor of maximum oxygen uptake (p = 0.001). In conclusion, the results of this study have demonstrated that NT-pro-BNP increases progressively with worsening symptoms, is linked to the extent of LV remodeling, and is an independent predictor of functional capacity. NT-pro-BNP may have a role in the optimal treatment of patients with severe mitral regurgitation.

The effects of adding torasemide to standard therapy on peak oxygen consumption, natriuretic peptides, and quality of life in patients with compensated left ventricular systolic dysfunction.

AIMS: Diuretics, when used to treat congestion in patients with chronic heart failure, improve symptoms and, perhaps, prognosis but little information is available to guide their use in patients with left ventricular systolic dysfunction (LVSD) who are not congested. Chronic diuretic therapy causes persistent and potentially harmful neuroendocrine activation. Alternatively, in patients in whom neuroendocrine activation is blocked with angiotensin-converting enzyme (ACE)-inhibitors and beta-blockers, diuretics may be beneficial by decreasing preload and afterload and preventing congestion. We aimed to assess the effect of the loop diuretic, torasemide on quality of life, and surrogate markers of prognosis when given to patients with LVSD who were not clinically congested and who were optimally treated with ACE-inhibitors (or angiotensin receptor antagonists) and beta-blockers. METHODS AND RESULTS: Thirty patients with stable LVSD who had no clinically detectable fluid overload were randomized to receive either torasemide 5 mg daily or placebo for 3 months (Phase A), and after a washout phase of 2 months, cross-over was performed for 3 months (Phase B). Diuretic therapy did not cause significant change in peak VO(2), mean N-terminal pro-hormone brain natriuretic peptide (NT-proBNP) levels, or measures of quality of life compared with placebo. Diuretic therapy did however lead to significant fall in systolic and diastolic blood pressures and increase in plasma renin levels compared with placebo. CONCLUSION: Diuretic therapy with torasemide is not superior to placebo in improving peak VO(2) or reducing NT-proBNP levels in patients with left ventricular dysfunction who are not clinically congested.