Prevalence and outcomes of diaphragmatic dysfunction assessed by ultrasound technology during acute exacerbation of COPD: A pilot study.

BACKGROUND AND OBJECTIVE: The prevalence and clinical consequences of diaphragmatic dysfunction (DD) during acute exacerbations of COPD (AECOPD) remain unknown. The aim of this study was (i) to evaluate the prevalence of DD as assessed by ultrasonography (US) and (ii) to report the impact of DD on non-invasive mechanical ventilation (NIV) failure, length of hospital stay and mortality in severe AECOPD admitted to respiratory intensive care unit (RICU). METHODS: Forty-one consecutive AECOPD patients with respiratory acidosis admitted over a 12-month period to the RICU of the University Hospital of Modena were studied. Diaphragmatic ultrasound (DU) was performed on admission before starting NIV. A change in diaphragmatic thickness (ΔTdi) less than 20% during spontaneous breathing was considered to confirm the presence of dysfunction (DD+). NIV failure and other clinical outcomes (duration of mechanical ventilation MV, tracheostomy, length of hospital stay and mortality) were recorded. RESULTS: A total of 10 out of 41 patients (24.3%) presented DD+, which was significantly associated with steroid use (P = 0.002, R-squared = 0.19). DD+ correlated with NIV failure (P < 0.001, R-squared = 0.27), longer intensive care unit (ICU) stay (P = 0.02, R-squared = 0.13), prolonged MV (P = 0.023, R-squared = 0.15) and need for tracheostomy (P = 0.006, R-squared = 0.20). Moreover, the Kaplan-Meyer survival estimates showed that NIV failure (log-rank test P value = 0.001, HR = 8.09 (95% CI: 2.7-24.2)) and mortality in RICU (log-rank test P value = 0.039, HR = 4.08 (95% CI: 1.0-16.4)) were significantly associated with DD+. CONCLUSION: In hospitalized AECOPD patients submitted to NIV, severe DD was seen in almost one-quarter of patients. DD may cause NIV failure, and impacts on the use of clinical resources and on the patient's short-term mortality.

Ultrasound assessment of diaphragmatic function in patients with amyotrophic lateral sclerosis.

BACKGROUND AND OBJECTIVE: Evaluation of diaphragm function in Amyotrophic Lateral Sclerosis (ALS) is critical in determining when to commence non-invasive mechanical ventilation (NIV). Currently, forced vital capacity (FVC) and sniff nasal inspiratory pressure (SNIP) are volitional measures for this evaluation, but require collaboration and are poorly specific. The primary aim of this study was to assess whether diaphragmatic thickness measured by ultrasound (US) correlates with lung function impairment in ALS patients. The secondary aim was then to compare US diaphragm thickness index (ΔTdi) with a new parameter (ΔTmax index). METHODS: 41 patients with ALS and 30 healthy subjects were enrolled in the study. All subjects underwent spirometry, SNIP and diaphragm US evaluation, while arterial blood gases were measured in some patients only. US assessed diaphragm thickness (Tdi) at tidal volume (Vt) or total lung capacity (TLC), and their ratio (ΔTmax) were recorded. Changes (Δ) in Tdi indices during tidal volume (ΔTdiVt) and maximal inspiration (ΔTdiTLC) were also assessed. RESULTS: ΔTdiTLC (p <0.001) and ΔTmax (p = 0.007), but not ΔTdiVt, differed between patients and controls. Significant correlation (p < 0.05) was found between ΔTdiTLC, ΔTmax and FVC. The ROC curve analysis for comparison of individual testing showed better accuracy with Δtmax than with ΔtdiTLC for FVC (AUC 0.76 and 0.27) and SNIP (AUC 0.71 and 0.25). CONCLUSION: Diaphragm thickness assessed by ultrasound significantly correlates with global respiratory alterations in patients with ALS. ΔTmax represents a new US index of early diaphragmatic dysfunction, better related with the routinely performed lung function tests.

Efficacy of temporary positive expiratory pressure (TPEP) in patients with lung diseases and chronic mucus hypersecretion. The UNIKO® project: a multicentre randomized controlled trial.

OBJECTIVE: To evaluate whether temporary positive expiratory pressure provides benefit in patients with lung diseases and chronic hypersecretion. DESIGN: Single blind multicentre randomized trial. SETTING: Five Italian rehabilitation centres. PARTICIPANTS: Ninety-eight patients with chronic obstructive pulmonary disease and/or chronic bronchitis (n=78), or bronchiectasis (n=20), with a peak cough expiratory flow >150 l/min and sputum production >30 ml/day, randomly included into two treatment groups. INTERVENTIONS: For 10 consecutive days, the active group performed twice a day 20-minute cycles of manually assisted breathing techniques in sequence with the addition of 15 minutes of temporary positive expiratory pressure, while the control group was treated by manually assisted breathing techniques alone. MEASURES: Within and between group changes of arterial oxygenation index, lung volumes and respiratory muscles strength were recorded at enrolment and after 3 and 10 treatment sessions. Pre-to-post treatment change of sputum volume and bronchial encumbrance (Δ-visual analog scale), sputum density and purulence were compared daily within the study period. RESULTS: No significant changes were recorded for the oxygenation index, while dynamic lung volumes and respiratory muscle strength significantly (P <0.05) improved in the active group. The group comparison analysis of the pre-to-post change showed that inspiratory capacity was significantly higher in the active than in the control group (+19.5% and +2.2%, P=0.044) at day 10. A greater improvement in Δ-visual analog scale was recorded in the active group at day 3 and 8. CONCLUSIONS: These preliminary data suggest that temporary positive expiratory pressure improves lung volumes and speeds up the improvement of bronchial encumbrance in patients with lung diseases and hypersecretion.

Exercise performance after standard rehabilitation in COPD patients with lung hyperinflation.

The role of pulmonary rehabilitation (PR) in COPD patients with lung hyperinflation has not yet been fully investigated. We retrospectively evaluated the effect of a standard PR course on exercise tolerance and symptoms according to the presence or absence of associated lung hyperinflation, as defined by lung function parameters in three Italian rehabilitation centres. In a cohort of 823 COPD patients (age 71 ± 8 years, FEV1 56 ± 18% pred.) we have systematically recorded: changes (∆) in 6-minute walking test (6MWD) as the primary outcome; dyspnoea (D); muscle fatigue (F); SO2nadir during effort; perceived breathlessness score (MRC); and specific health-related quality of life (SGRQ). Outcomes were compared between patients with lung hyperinflation (n = 283, LH) or without (n = 540 No-LH). Groups were comparable for age, body mass index, baseline exercise tolerance, and breathlessness. ∆-6MWD (+72 ± 47 vs. +62 ± 42 m, p < 0.05); ∆-D (-2.3 ± 1.7 vs. -1.9 ± 1.3 point, p < 0.05) and ∆-SO2nadir (+1.4 ± 3.0 and +0.5 ± 3.3 point, p < 0.05) were greater in LH than in No-LH. Using a multivariate linear regression model, ∆-6MWD in the LH group significantly correlated with lower functional residual capacity (p = 0.021) and baseline 6MWD (p = 0.004). Tolerance, gas exchange and perceived symptoms during effort are the parameters that gain a significant benefit from standard rehabilitation in COPD patients with a lung hyperinflation condition.

Predicting walking-induced oxygen desaturations in COPD patients: a statistical model.

BACKGROUND: Oxygen desaturation during walking can have important consequence on prognosis of COPD patients. However, a standard 6-min walk test (6MWT), useful in detecting desaturation in COPD patients, can be difficult to execute in some settings of COPD management, as in the community healthcare service. We evaluated a new scoring system for the risk of oxygen desaturation during walking in COPD patients: the walking desaturation score. METHODS: We collected data from symptomatic COPD in-patients admitted for rehabilitation (derivation cohort) and out-patients referred to the local community health service (validation cohort). S(pO2) was monitored during 6MWT, and the subjects were classified as walking desaturators or non-desaturators. By a regression analysis model we assigned a weighted score proportional to the measured percentage of explained variance for each variable. Risk estimates were computed as odds ratios. A receiver operating characteristic curve analysis and a Hosmer-Lemeshow goodness-of-fit test were then performed to measure discrimination and calibration of walking desaturation score. RESULTS: Baseline characteristics in the derivation cohort (n = 435, 74% of whom were walking desaturators) and the validation cohort (n = 238, 37% of whom were walking desaturators) were different. Resting arterial oxygen saturation measured from an arterial blood sample, P(aO2), and percent-of-predicted FEV1 were the variables that predicted walking desaturation. The proportion of walking desaturators (and odds ratio estimate) gradually increased according to walking desaturation score (range 0-6) and associated categories of desaturation risk (total walking desaturation score: low 0 or 1, high 2-3, very high 4-6) (chi-square P < .001). There was considerable predictive discrimination (area under the curve 0.90, 95% CI 0.86-0.93, P < .001), and calibration (Hosmer-Lemeshow chi-square 1.31, P = .86) values have been shown. CONCLUSIONS: Walking desaturation score accurately predicts and classifies the risk of walking desaturation in COPD patients. ClinicalTrials.gov Number NCT01303913.