Effect of portable noninvasive ventilation on thoracoabdominal volumes in recovery from intermittent exercise in patients with COPD.

We previously showed that use of portable noninvasive ventilation (pNIV) during recovery periods within intermittent exercise improved breathlessness and exercise tolerance in patients with COPD compared with pursed-lip breathing (PLB). However, in a minority of patients recovery from dynamic hyperinflation (DH) was better with PLB, based on inspiratory capacity. We further explored this using Optoelectronic Plethysmography to assess total and compartmental thoracoabdominal volumes. Fourteen patients with COPD (means ± SD) (FEV1: 55% ± 22% predicted) underwent, in a balanced order sequence, two intermittent exercise protocols on the cycle ergometer consisting of five repeated 2-min exercise bouts at 80% peak capacity, separated by 2-min recovery periods, with application of pNIV or PLB in the 5 min of recovery. Our findings identified seven patients showing recovery in DH with pNIV (DH responders) whereas seven showed similar or better recovery in DH with PLB. When pNIV was applied, DH responders compared with DH nonresponders exhibited greater tidal volume (by 0.8 ± 0.3 L, P = 0.015), inspiratory flow rate (by 0.6 ± 0.5 L/s, P = 0.049), prolonged expiratory time (by 0.6 ± 0.5 s, P = 0.006), and duty cycle (by 0.7 ± 0.6 s, P = 0.007). DH responders showed a reduction in end-expiratory thoracoabdominal DH (by 265 ± 633 mL) predominantly driven by reduction in the abdominal compartment (by 210 ± 494 mL); this effectively offset end-inspiratory rib-cage DH. Compared with DH nonresponders, DH responders had significantly greater body mass index (BMI) by 8.4 ± 3.2 kg/m2, P = 0.022 and tended toward less severe resting hyperinflation by 0.3 ± 0.3 L. Patients with COPD who mitigate end-expiratory rib-cage DH by expiratory abdominal muscle recruitment benefit from pNIV application.NEW & NOTEWORTHY Compared with the pursed-lip breathing technique, acute application of portable noninvasive ventilation during recovery from intermittent exercise improved end-expiratory thoracoabdominal dynamic hyperinflation (DH) in 50% of patients with COPD (DH responders). DH responders, compared with DH nonresponders, exhibited a reduction in end-expiratory thoracoabdominal DH predominantly driven by the abdominal compartment that effectively offset end-expiratory rib cage DH. The essential difference between DH responders and DH nonresponders was, therefore, in the behavior of the abdomen.

Coding of COPD Exacerbations and the Implications on Clinical Practice, Audit and Research.

International Classification of Disease 10 (ICD-10) codes record hospital admissions. We aimed to measure the accuracy of COPD exacerbation (ECOPD) codes and examine coding practices for COPD exacerbation.Prospective screening and ICD-10 codes were used to identify potential ECOPD within the DECAF internal validation cohort. Two coding searches were performed. The first search identified patients with an ECOPD discharge code, and a second, broad search was developed to identify all clinically confirmed ECOPD.717 of 1,122 (64%) patients with an ECOPD code had confirmed ECOPD. Common reasons for misclassification in the 405 patients who did not have an ECOPD included: lack of obstructive spirometry to diagnose COPD; and hospital admission due to progressive malignancy, asthma or cardiovascular disease. The broad search identified an additional 297 patients with ECOPD missed by the ECOPD codes. The vast majority of this group had pneumonia complicating ECOPD.ECOPD codes are insufficiently reliable to identify patients with clinically confirmed ECOPD for the purposes of audit or research. Search strategies should include pneumonia codes, specialist review of medical notes and spirometry confirmation of COPD.

The PEARL score predicts 90-day readmission or death after hospitalisation for acute exacerbation of COPD.

BACKGROUND: One in three patients hospitalised due to acute exacerbation of COPD (AECOPD) is readmitted within 90 days. No tool has been developed specifically in this population to predict readmission or death. Clinicians are unable to identify patients at particular risk, yet resources to prevent readmission are allocated based on clinical judgement. METHODS: In participating hospitals, consecutive admissions of patients with AECOPD were identified by screening wards and reviewing coding records. A tool to predict 90-day readmission or death without readmission was developed in two hospitals (the derivation cohort) and validated in: (a) the same hospitals at a later timeframe (internal validation cohort) and (b) four further UK hospitals (external validation cohort). Performance was compared with ADO, BODEX, CODEX, DOSE and LACE scores. RESULTS: Of 2417 patients, 936 were readmitted or died within 90 days of discharge. The five independent variables in the final model were: Previous admissions, eMRCD score, Age, Right-sided heart failure and Left-sided heart failure (PEARL). The PEARL score was consistently discriminative and accurate with a c-statistic of 0.73, 0.68 and 0.70 in the derivation, internal validation and external validation cohorts. Higher PEARL scores were associated with a shorter time to readmission. CONCLUSIONS: The PEARL score is a simple tool that can effectively stratify patients' risk of 90-day readmission or death, which could help guide readmission avoidance strategies within the clinical and research setting. It is superior to other scores that have been used in this population. TRIAL REGISTRATION NUMBER: UKCRN ID 14214.

Validation of the DECAF score to predict hospital mortality in acute exacerbations of COPD.

BACKGROUND: Hospitalisation due to acute exacerbations of COPD (AECOPD) is common, and subsequent mortality high. The DECAF score was derived for accurate prediction of mortality and risk stratification to inform patient care. We aimed to validate the DECAF score, internally and externally, and to compare its performance to other predictive tools. METHODS: The study took place in the two hospitals within the derivation study (internal validation) and in four additional hospitals (external validation) between January 2012 and May 2014. Consecutive admissions were identified by screening admissions and searching coding records. Admission clinical data, including DECAF indices, and mortality were recorded. The prognostic value of DECAF and other scores were assessed by the area under the receiver operator characteristic (AUROC) curve. RESULTS: In the internal and external validation cohorts, 880 and 845 patients were recruited. Mean age was 73.1 (SD 10.3) years, 54.3% were female, and mean (SD) FEV1 45.5 (18.3) per cent predicted. Overall mortality was 7.7%. The DECAF AUROC curve for inhospital mortality was 0.83 (95% CI 0.78 to 0.87) in the internal cohort and 0.82 (95% CI 0.77 to 0.87) in the external cohort, and was superior to other prognostic scores for inhospital or 30-day mortality. CONCLUSIONS: DECAF is a robust predictor of mortality, using indices routinely available on admission. Its generalisability is supported by consistent strong performance; it can identify low-risk patients (DECAF 0-1) potentially suitable for Hospital at Home or early supported discharge services, and high-risk patients (DECAF 3-6) for escalation planning or appropriate early palliation. TRIAL REGISTRATION NUMBER: UKCRN ID 14214.

Phenotyping adults with non-cystic fibrosis bronchiectasis: a prospective observational cohort study.

BACKGROUND: Bronchiectasis is the outcome of a number of different airway insults. Very few studies have characterised the aetiology and utility of a dedicated screening proforma in adult patients attending a general bronchiectasis clinic. METHODS: A prospective observational study of 189 bronchiectasis patients attending two centres in the North East of England over a two-year period was performed. RESULTS: The aetiology of bronchiectasis was identified in 107/189(57%) patients. Idiopathic bronchiectasis (IB) represented the largest subgroup (43%). Post-infection bronchiectasis (PIB) constituted the largest proportion (24%) of known causes. Mean age (SD) at diagnosis was 54(20) years with a mean age at symptom onset of 37(24) years, accounting for a diagnostic delay of 17 years. Age of symptom onset was significantly younger in patients with PIB compared to IB (p < 0.0001) and in Pseudomonas sputum positive patients (p = 0.007). Screening for APBA and total immunoglobulin deficiency identified 9 (5%) patients who then had tailored treatment. Routine screening for other aetiologies was deemed unnecessary. CONCLUSION: IB and PIB accounted for two thirds of cases of bronchiectasis in a general population. We recommend routine screening for ABPA and total immunoglobulin deficiency but not for other rarer aetiologies.

Profound bradycardia associated with NIV removal.

A patient with lower-limb onset ALS presented with a one-month history of vasovagal episodes and a one-week history of cough productive of green sputum and lethargy. She was drowsy and in acute on chronic type-two respiratory failure. She responded to non-invasive ventilation, however she suffered recurrent episodes of profound bradycardia on removal of the mask, which gradually resolved over ten days. We have reviewed the literature and offer a potential explanation for these events.

Dyspnoea severity and pneumonia as predictors of in-hospital mortality and early readmission in acute exacerbations of COPD.

BACKGROUND: Rates of mortality and readmission are high in patients hospitalised with acute exacerbations of chronic obstructive pulmonary disease (AECOPD). In this population, the prognostic value of the Medical Research Council Dyspnoea Scale (MRCD) is uncertain, and an extended MRCD (eMRCD) scale has been proposed to improve its utility. Coexistent pneumonia is common and, although the CURB-65 prediction tool is used, its discriminatory value has not been reported. METHODS: Clinical and demographic data were collected on consecutive patients hospitalised with AECOPD. The relationship of stable-state dyspnoea severity to in-hospital mortality and 28-day readmission was assessed. The discriminatory value of CURB-65, MRCD and eMRCD, in the prediction of in-hospital mortality, was assessed and compared. RESULTS: 920 patients were recruited. 10.4% died in-hospital and 19.1% of the 824 survivors were readmitted within 28 days of discharge. During their stable state prior to admission, 34.2% of patients were too breathless to leave the house. Mortality was significantly higher in pneumonic than in non-pneumonic exacerbations (20.1% vs 5.8%, p<0.001). eMRCD was a significantly better discriminator than either CURB-65 or the traditional MRCD scale for predicting in-hospital mortality, and was a stronger prognostic tool than CURB-65 in the subgroup of patients with pneumonic AECOPD. CONCLUSIONS: The severity of dyspnoea in the stable state predicts important clinical outcomes in patients hospitalised with AECOPD. The eMRCD scale identifies a subgroup of patients at a particularly high risk of in-hospital mortality and is a better predictor of mortality risk than CURB-65 in exacerbations complicated by pneumonia.

Predicting outcomes following hospitalization for acute exacerbations of COPD.

Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) are a frequent cause of hospital admission and are associated with significant morbidity, mortality, high readmission rates and high resource utilization. More accurate prediction of survival and readmission in patients hospitalized with AECOPD should help to optimize clinical management and allocation of resources, including targeting of palliative care and strategies to reduce readmissions. We have reviewed the published retrospective and prospective studies in this field to identify the factors most likely to be of value in predicting in-hospital and post-discharge mortality, and readmission of patients hospitalized for AECOPD. The prognostic factors which appear most important vary with the particular outcome under consideration. In-hospital mortality is related most clearly to the patient's acute physiological state and to the development of acute comorbidity, while post-discharge mortality particularly reflects the severity of the underlying COPD, as well as specific comorbidities, especially cardiac disease. Important factors influencing the frequency of readmission include functional limitation and poor health-related quality of life. Large prospective studies which incorporate all the potentially relevant variables are required to refine prediction of the important outcomes of AECOPD and thus to inform clinical decision making, for example on escalation of care, facilitated discharge and provision of palliative care.

Effects of long-term low-dose azithromycin in patients with non-CF bronchiectasis.

UNLABELLED: We describe our institutional efficacy experience of azithromycin 250 mg thrice weekly in adult non-cystic fibrosis bronchiectasis. METHODS: Eligibility criteria for prophylactic azithromycin included 3 exacerbations requiring rescue antibiotics over the previous 6 months. The clinical records of 56 bronchiectasis patients on azithromycin were retrospectively reviewed. Exacerbation frequency, sputum microbiology, self-reported change in sputum volume, and spirometry results were recorded. RESULTS: Mean length of treatment was 9.1 months (7.5) and 50 patients had treatment > or = 3 months. Spirometry, pre- and post-azithromycin in 29 patients, who had 3 or more months of treatment, showed a mean increase in FEV(1) of 83 ml (0.14) (P=0.005) from 1.560 to 1.643l. There was a decrease in the exacerbation frequency from 0.81/month (SD) (0.32) pre-azithromycin to 0.41/month (0.45) (P<0.001) post-azithromycin. Clinically significant suppression of previous sputum microbial isolates was also observed. CONCLUSION: Azithromycin improves exacerbation frequency, spirometry, and sputum microbiology in bronchiectasis.

Validation of quality of life instruments in ALS.

BACKGROUND: Non-invasive ventilation (NIV) probably improves survival in ALS, but its effect on quality of life (QoL) is less clear. Most potentially useful QoL instruments have not been validated in this context. METHODS: We assessed the validity (multi-trait multi-method analysis), internal consistency (Cronbach's alpha), test-retest stability (intra-class correlations) and response to disease severity and NIV (effect size) of two generic instruments, the Short Form 36 (SF-36) and the General Well-being Schedule; two specific instruments, the Chronic Respiratory Disease Questionnaire (CRQ) and the Sleep Apnoea QoL Index (SAQLI), and a scale of daytime sleepiness, the Epworth Sleepiness Scale (ESS) in 23 subjects with ALS. Functional status, limb and axial muscle strength, and maximum inspiratory pressure were assessed, together with the QoL measurements, every two months. RESULTS: All instruments showed good or excellent validity, internal consistency and test-retest stability overall. Subjects without symptomatic respiratory compromise had difficulty identifying activities for the CRQ dyspnoea domain and symptoms for the SAQLI symptoms domain. Marked floor effects were observed in the physical function and role domains of the SF-36. Domains assessing sleep-related problems and mental health showed greater effect of differences in respiratory function than functional status, and the greatest response to NIV. CONCLUSIONS: Of the generic instruments the SF-36 was most useful, but limited by floor effects. Of the specific instruments, the SAQLI symptoms domain was most responsive to NIV, but this instrument took longer to complete, and several items were inappropriate. The CRQ and ESS are valid and responsive alternatives.

Erdheim-Chester disease: pulmonary infiltration responding to cyclophosphamide and prednisolone.

Erdheim-Chester disease is a rare multisystem histiocytic disorder in which death most commonly results from pulmonary or cardiac involvement. We report the case history of a 55 year old man with this condition with extensive and progressive pulmonary disease. He had no response to prednisolone alone, but treatment with prednisolone plus cyclophosphamide was associated with a rapid improvement in symptoms, lung function, and the chest radiographic appearance. He subsequently showed a symptomatic, functional, and radiological deterioration, followed by a marked slowing in the rate of decline. He currently remains stable 41 months after treatment was initiated. This is the first report of pulmonary Erdheim-Chester disease showing improvement in both lung function and symptoms with any form of treatment.

Noninvasive ventilation in ALS: indications and effect on quality of life.

BACKGROUND: Noninvasive ventilation (NIV) probably improves survival in ALS, but the magnitude and duration of any improvement in quality of life (QoL) and the optimal criteria for initiating treatment are unclear. METHODS: QoL (Short Form-36 [SF-36], Chronic Respiratory Disease Questionnaire, Sleep Apnea Quality of Life Index) and respiratory function were assessed every 2 months and polysomnography every 4 months in 22 subjects with ALS. A trial of NIV was offered when subjects met one or more predefined criteria: orthopnea, daytime sleepiness, unrefreshing sleep, daytime hypercapnia, nocturnal desaturation, or an apnea-hypopnea index (AHI) of >10. Seventeen subjects were offered a trial of NIV; 15 accepted, and 10 continued treatment subsequently. Outcome was assessed by changes in QoL and NIV compliance (h/day). Subjects were followed to death or for at least 26 months. RESULTS: QoL domains assessing sleep-related problems and mental health improved (effect sizes 0.88 to 1.77, p < 0.05) and were maintained for 252 to 458 days. Median survival following successful initiation of NIV was 512 days, and survival and duration of QoL benefit were strongly related to NIV compliance. Vital capacity declined more slowly following initiation of NIV. Orthopnea was the best predictor of benefit from, and compliance with, NIV. Daytime hypercapnia and nocturnal desaturation also predicted benefit but were less sensitive. Sleep-related symptoms were less specific, and AHI > 10 was unhelpful. Moderate or severe bulbar weakness was associated with lower compliance and less improvement in QoL. CONCLUSIONS: NIV use was associated with improved QoL and survival. Subjects with orthopnea and preserved bulbar function showed the largest benefit.

Non-invasive ventilation in motor neuron disease: current UK practice.

OBJECTIVE: To evaluate the clinical application of non-invasive ventilation (NIV) in motor neuron disease (MND) in the UK. METHOD: We conducted a postal survey of the current clinical practice of all consultant neurologists in the UK, with a second mailing to non-responders after 6 weeks. The principal outcome measures assessed were: 1. the percentage of patients with MND receiving NIV, 2. access to a NIV service, 3. routine monitoring of respiratory function, and 4. influence of symptoms, respiratory function, rate of disease progression, level of disability and bulbar involvement on referral for NIV. RESULTS: The response rate was 76%, 1719 new patients had been diagnosed in the preceding 12 months and a total of 2280 patients were under review. Of these, 126 were currently receiving NIV (5.5% of patients under review, estimated 2.6-3.5% of all MND patients). Most neurologists (172/265) had referred no patients for NIV in the preceding year, while three neurologists made 30% of all referrals nationally. Referral was based primarily on symptoms, and was influenced by the number of MND patients under review, level of disability, rate of disease progression and availability of a NIV service. Bulbar involvement was considered a relative contra-indication to NIV by 51% of responders. CONCLUSIONS: In the UK, few patients with MND are treated with NIV. There is marked variation in clinical practice. This may reflect uncertainty about the role of non-invasive ventilation in MND, and emphasizes the need for a randomized controlled trial to assess the impact of NIV on quality of life and survival.

Sleep and breathing in neuromuscular disease.

Respiratory muscle weakness in neuromuscular disease causes significant morbidity and mortality. The published data on respiratory muscle activity and breathing during sleep in normal subjects, the impact of respiratory muscle weakness on sleep and breathing and the relations to daytime respiratory function in neuromuscular disease are reviewed here. In normal subjects during sleep upper airway resistance increases, chemosensitivity is reduced and the wakefulness drive to breathe is lost, resulting in a fall in ventilation. During rapid eye movement (REM) sleep, ribcage and accessory breathing muscles are suppressed, particularly during bursts of eye movements, and breathing is more irregular, rapid and shallow, with a further fall in ventilation. In subjects with respiratory muscle weakness sleep is fragmented, with shorter total sleep time, frequent arousals, an increase in stage 1 sleep and a reduction in, or complete suppression of, REM sleep. Sleep-disordered breathing and nocturnal desaturation are common and most severe during REM sleep. Correlations between daytime respiratory function and nocturnal desaturation are moderate or weak, but daytime respiratory function has greater prognostic value than nocturnal measurements. Noninvasive ventilation improves sleep quality and breathing in subjects with respiratory muscle weakness. However, the optimal criteria for initiation of ventilation and its role in rapidly progressive neuromuscular diseases are unclear.

Respiratory function vs sleep-disordered breathing as predictors of QOL in ALS.

BACKGROUND: Most patients with ALS have evidence of respiratory muscle weakness at diagnosis, and death is usually due to respiratory failure. Sleep disruption, possibly due to apneas, hypopneas, orthopnea, or REM-related desaturation, is common. The relative impact of these factors on quality of life has not been established. METHODS: The authors recruited 23 subjects with probable or definite ALS. Quality of life was assessed using generic and specific instruments, and respiratory muscle strength by measurement of vital capacity, maximum static pressures, and sniff nasal inspiratory pressure. Twenty-two subjects underwent polysomnography. Overall limb and axial muscle strength was estimated using a summated muscle score based on the Medical Research Council clinical scale. RESULTS: On univariate analysis, there were moderate to strong correlations between quality of life and all measurements of respiratory muscle function (R = 0.42-0.82). The correlations with selected polysomnographic indices were weaker and less consistent (R = 0.44-0.59). Multivariate analysis showed that maximum static inspiratory pressure was the strongest independent predictor of quality of life. CONCLUSION: Quality of life was strongly and independently related to respiratory muscle function. Relations with polysomnographic indices were weaker and were attributable to respiratory muscle weakness. Respiratory muscle weakness is much more important than the frequency of apneas and hypopneas in determining quality of life in ALS.