Publications by authors named "Caroline Jolley"

61 Publications

Physical, cognitive, and mental health impacts of COVID-19 after hospitalisation (PHOSP-COVID): a UK multicentre, prospective cohort study.

Lancet Respir Med 2021 11 7;9(11):1275-1287. Epub 2021 Oct 7.

Hywel Dda University Health Board, Wales, UK; University of Swansea, Swansea, UK; Respiratory Innovation Wales, Llanelli, UK.

Background: The impact of COVID-19 on physical and mental health and employment after hospitalisation with acute disease is not well understood. The aim of this study was to determine the effects of COVID-19-related hospitalisation on health and employment, to identify factors associated with recovery, and to describe recovery phenotypes.

Methods: The Post-hospitalisation COVID-19 study (PHOSP-COVID) is a multicentre, long-term follow-up study of adults (aged ≥18 years) discharged from hospital in the UK with a clinical diagnosis of COVID-19, involving an assessment between 2 and 7 months after discharge, including detailed recording of symptoms, and physiological and biochemical testing. Multivariable logistic regression was done for the primary outcome of patient-perceived recovery, with age, sex, ethnicity, body-mass index, comorbidities, and severity of acute illness as covariates. A post-hoc cluster analysis of outcomes for breathlessness, fatigue, mental health, cognitive impairment, and physical performance was done using the clustering large applications k-medoids approach. The study is registered on the ISRCTN Registry (ISRCTN10980107).

Findings: We report findings for 1077 patients discharged from hospital between March 5 and Nov 30, 2020, who underwent assessment at a median of 5·9 months (IQR 4·9-6·5) after discharge. Participants had a mean age of 58 years (SD 13); 384 (36%) were female, 710 (69%) were of white ethnicity, 288 (27%) had received mechanical ventilation, and 540 (50%) had at least two comorbidities. At follow-up, only 239 (29%) of 830 participants felt fully recovered, 158 (20%) of 806 had a new disability (assessed by the Washington Group Short Set on Functioning), and 124 (19%) of 641 experienced a health-related change in occupation. Factors associated with not recovering were female sex, middle age (40-59 years), two or more comorbidities, and more severe acute illness. The magnitude of the persistent health burden was substantial but only weakly associated with the severity of acute illness. Four clusters were identified with different severities of mental and physical health impairment (n=767): very severe (131 patients, 17%), severe (159, 21%), moderate along with cognitive impairment (127, 17%), and mild (350, 46%). Of the outcomes used in the cluster analysis, all were closely related except for cognitive impairment. Three (3%) of 113 patients in the very severe cluster, nine (7%) of 129 in the severe cluster, 36 (36%) of 99 in the moderate cluster, and 114 (43%) of 267 in the mild cluster reported feeling fully recovered. Persistently elevated serum C-reactive protein was positively associated with cluster severity.

Interpretation: We identified factors related to not recovering after hospital admission with COVID-19 at 6 months after discharge (eg, female sex, middle age, two or more comorbidities, and more acute severe illness), and four different recovery phenotypes. The severity of physical and mental health impairments were closely related, whereas cognitive health impairments were independent. In clinical care, a proactive approach is needed across the acute severity spectrum, with interdisciplinary working, wide access to COVID-19 holistic clinical services, and the potential to stratify care.

Funding: UK Research and Innovation and National Institute for Health Research.
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http://dx.doi.org/10.1016/S2213-2600(21)00383-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8497028PMC
November 2021

Pulmonary Effects of Sustained Periods of High-G Acceleration Relevant to Suborbital Spaceflight.

Aerosp Med Hum Perform 2021 Aug;92(8):633-641

Members of the public will soon be taking commercial suborbital spaceflights with significant G (chest-to-back) acceleration potentially reaching up to 6 G. Pulmonary physiology is gravity-dependent and is likely to be affected, which may have clinical implications for medically susceptible individuals. During 2-min centrifuge exposures ranging up to 6 G, 11 healthy subjects were studied using advanced respiratory techniques. These sustained exposures were intended to allow characterization of the underlying pulmonary response and did not replicate actual suborbital G profiles. Regional distribution of ventilation in the lungs was determined using electrical impedance tomography. Neural respiratory drive (from diaphragm electromyography) and work of breathing (from transdiaphragmatic pressures) were obtained via nasoesophageal catheters. Arterial blood gases were measured in a subset of subjects. Measurements were conducted while breathing air and breathing 15 oxygen to simulate anticipated cabin pressurization conditions. Acceleration caused hypoxemia that worsened with increasing magnitude and duration of G. Minimum arterial oxygen saturation at 6 G was 86 1 breathing air and 79 1 breathing 15 oxygen. With increasing G the alveolar-arterial (A-a) oxygen gradient widened progressively and the relative distribution of ventilation reversed from posterior to anterior lung regions with substantial gas-trapping anteriorly. Severe breathlessness accompanied large progressive increases in work of breathing and neural respiratory drive. Sustained high-G acceleration at magnitudes relevant to suborbital flight profoundly affects respiratory physiology. These effects may become clinically important in the most medically susceptible passengers, in whom the potential role of centrifuge-based preflight evaluation requires further investigation.
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http://dx.doi.org/10.3357/AMHP.5790.2021DOI Listing
August 2021

Dynamic lung behavior under high G acceleration monitored with electrical impedance tomography.

Physiol Meas 2021 09 27;42(9). Epub 2021 Sep 27.

Medical Information Technology (MedIT), Helmholtz-Institute for Biomedical Engineering, RWTH Aachen University, Pauwelsstr. 20, D-52074 Aachen, Germany.

. During launch and atmospheric re-entry in suborbital space flights, astronauts are exposed to high G-acceleration. These acceleration levels influence gas exchange inside the lung and can potentially lead to hypoxaemia. The distribution of air inside the lung can be monitored by electrical impedance tomography. This imaging technique might reveal how high gravitational forces affect the dynamic behavior of ventilation and impair gas exchange resulting in hypoxaemia.. We performed a trial in a long-arm centrifuge with ten participants lying supine while being exposed to +2, +4 and +6 G(chest-to-back acceleration) to study the magnitude of accelerations experienced during suborbital spaceflight.. First, the tomographic images revealed that the dorsal region of the lung emptied faster than the ventral region. Second, the ventilated area shifted from dorsal to ventral. Consequently, alveolar pressure in the dorsal area reached the pressure of the upper airways before the ventral area emptied completely. Finally, the upper airways collapsed and the end-expiratory volume increased. This resulted in ventral gas trapping with restricted gas exchange.. At +4 G, changes in ventilation distribution varied considerably between subjects, potentially due to variation in individual physical conditions. However, at +6 Gall participants were affected similarly and the influence of high gravitational conditions was pronounced.
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http://dx.doi.org/10.1088/1361-6579/ac1c63DOI Listing
September 2021

Identifying bronchoconstriction from the ratio of diaphragm EMG to tidal volume.

Respir Physiol Neurobiol 2021 09 18;291:103692. Epub 2021 May 18.

State Key Laboratory of Respiratory Disease, Guangzhou Medical University, Guangzhou, China; Faculty of Life Sciences and Medicine, King's College London School of Medicine, London, UK; Adelaide Institute for Sleep Health, College of Medicine and Public Health, Flinders University, Australia. Electronic address:

Background: A fall of ≥ 20 % in forced expiratory volume in the first second (FEV1) with a cumulative dose of histamine ≤ 7.8 μmol is considered to indicate bronchial hyperactivity, but no method exists for patients who cannot perform spirometry properly. Here we hypothesized that increases in respiratory central output measured by chest wall electromyography of the diaphragm (EMGdi-c) expressed as a function of tidal volume (EMGdi-c/VT) would have discriminative power to detect a 'positive' challenge test.

Methods: In a physiological study EMGdi was recorded from esophageal electrode (EMGdi-e) in 16 asthma patients and 16 healthy subjects during a histamine challenge test. In a second study, EMGdi from chest wall surface electrodes (EMGdi-c) was measured during a histamine challenge in 44 asthma patients and 51 healthy subjects. VT was recorded from a digital flowmeter during both studies.

Results: With histamine challenge test the change in EMGdi-e/VT in patients with asthma was significantly higher than that in healthy subjects (104.2 % ± 48.6 % vs 0.03 % ± 17.1 %, p < 0.001). Similarly there was a significant difference in the change of EMGdi-c/VT between patients with asthma and healthy subjects (90.5 % ± 75.5 % vs 2.4 % ± 21.7 %, p < 0.001). At the optimal cut-off point (29 % increase in EMGdi-c/VT), the area under the ROC curve (AUC) for detection of a positive test was 0.91 (p < 0.001) with sensitivity 86 % and specificity 92 %.

Conclusions: We conclude that EMGdi-c/VT may be used as an alternative for the assessment of bronchial hypersensitivity and airway reversibility to differentiate patients with asthma from healthy subjects.
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http://dx.doi.org/10.1016/j.resp.2021.103692DOI Listing
September 2021

Second intercostal space electromyography as a measure of neural respiratory drive: Clinical utility and validity.

Respir Physiol Neurobiol 2021 08 8;290:103683. Epub 2021 May 8.

Centre for Human & Applied Physiological Sciences, King's College London, London, UK. Electronic address:

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http://dx.doi.org/10.1016/j.resp.2021.103683DOI Listing
August 2021

Noninvasive Assessment of Neuromechanical Coupling and Mechanical Efficiency of Parasternal Intercostal Muscle during Inspiratory Threshold Loading.

Sensors (Basel) 2021 Mar 4;21(5). Epub 2021 Mar 4.

Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology (BIST), UPC Campus Diagonal-Besòs, Av. d'Eduard Maristany 10-14, 08019 Barcelona, Spain.

This study aims to investigate noninvasive indices of neuromechanical coupling (NMC) and mechanical efficiency (MEff) of parasternal intercostal muscles. Gold standard assessment of diaphragm NMC requires using invasive techniques, limiting the utility of this procedure. Noninvasive NMC indices of parasternal intercostal muscles can be calculated using surface mechanomyography (sMMG) and electromyography (sEMG). However, the use of sMMG as an inspiratory muscle mechanical output measure, and the relationships between sMMG, sEMG, and simultaneous invasive and noninvasive pressure measurements have not previously been evaluated. sEMG, sMMG, and both invasive and noninvasive measurements of pressures were recorded in twelve healthy subjects during an inspiratory loading protocol. The ratios of sMMG to sEMG, which provided muscle-specific noninvasive NMC indices of parasternal intercostal muscles, showed nonsignificant changes with increasing load, since the relationships between sMMG and sEMG were linear (R = 0.85 (0.75-0.9)). The ratios of mouth pressure (P) to sEMG and sMMG were also proposed as noninvasive indices of parasternal intercostal muscle NMC and MEff, respectively. These indices, similar to the analogous indices calculated using invasive transdiaphragmatic and esophageal pressures, showed nonsignificant changes during threshold loading, since the relationships between P and both sEMG (R = 0.84 (0.77-0.93)) and sMMG (R = 0.89 (0.85-0.91)) were linear. The proposed noninvasive NMC and MEff indices of parasternal intercostal muscles may be of potential clinical value, particularly for the regular assessment of patients with disordered respiratory mechanics using noninvasive wearable and wireless devices.
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http://dx.doi.org/10.3390/s21051781DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7961675PMC
March 2021

Three-month follow-up of pulmonary embolism in patients with COVID-19.

Thromb Res 2021 05 26;201:113-115. Epub 2021 Feb 26.

King's Thrombosis Centre, Department of Haematological Medicine, King's College Hospital NHS Foundation Trust, London, UK. Electronic address:

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http://dx.doi.org/10.1016/j.thromres.2021.02.023DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7908844PMC
May 2021

Chest radiography is a poor predictor of respiratory symptoms and functional impairment in survivors of severe COVID-19 pneumonia.

ERJ Open Res 2021 Jan 8;7(1). Epub 2021 Feb 8.

Centre for Human and Applied Physiological Sciences, King's College London, London, UK.

Background: A standardised approach to assessing COVID-19 survivors has not been established, largely due to the paucity of data on medium- and long-term sequelae. Interval chest radiography is recommended following community-acquired pneumonia; however, its utility in monitoring recovery from COVID-19 pneumonia remains unclear.

Methods: This was a prospective single-centre observational cohort study. Patients hospitalised with severe COVID-19 pneumonia (admission duration ≥48 h and oxygen requirement ≥40% or critical care admission) underwent face-to-face assessment at 4-6 weeks post-discharge. The primary outcome was radiological resolution of COVID-19 pneumonitis (Radiographic Assessment of Lung Oedema score <5). Secondary outcomes included clinical outcomes, symptom questionnaires, mental health screening (Trauma Screening Questionnaire, seven-item Generalised Anxiety Disorder assessment and nine-item Patient Health Questionnaire) and physiological testing (4-m gait speed (4MGS) and 1-min Sit-to-Stand (STS) tests).

Results: 119 patients were assessed between June 3, 2020 and July 2, 2020 at median (interquartile range (IQR)) 61 (51-67) days post-discharge: mean±sd age 58.7±14.4 years, median (IQR) body mass index 30.0 (25.9-35.2) kg·m, 62% male and 70% ethnic minority. Despite radiographic resolution of pulmonary infiltrates in 87%, modified Medical Research Council Dyspnoea (breathlessness) scale grades were above pre-COVID-19 baseline in 44%, and patients reported persistent fatigue (68%), sleep disturbance (57%) and breathlessness (32%). Screening thresholds were breached for post-traumatic stress disorder (25%), anxiety (22%) and depression (18%). 4MGS was slow (<0.8 m·s) in 38% and 35% desaturated by ≥4% during the STS test. Of 56 thoracic computed tomography scans performed, 75% demonstrated COVID-19-related interstitial and/or airways disease.

Conclusions: Persistent symptoms, adverse mental health outcomes and physiological impairment are common 2 months after severe COVID-19 pneumonia. Follow-up chest radiography is a poor marker of recovery; therefore, holistic face-to-face assessment is recommended to facilitate early recognition and management of post-COVID-19 sequelae.
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http://dx.doi.org/10.1183/23120541.00655-2020DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7585700PMC
January 2021

Provision of holistic care after severe COVID-19 pneumonia - Authors' reply.

Lancet Respir Med 2021 03 5;9(3):e25. Epub 2021 Feb 5.

Centre for Human and Applied Physiological Sciences, King's College London, London WC2R 2LS, UK; Department of Respiratory Medicine, King's College Hospital NHS Foundation Trust, London, UK. Electronic address:

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http://dx.doi.org/10.1016/S2213-2600(21)00014-XDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7906704PMC
March 2021

Parasternal electromyography as a surrogate measure of neural respiratory drive: Practical application and validity of surface and implanted fine wire methods.

Respir Physiol Neurobiol 2021 05 24;287:103602. Epub 2021 Jan 24.

Lane Fox Clinical Respiratory Physiology Research Centre, Guy's and St Thomas' NHS Foundation Trust, London, UK; Centre for Human & Applied Physiological Sciences, King's College London, London, UK. Electronic address:

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http://dx.doi.org/10.1016/j.resp.2020.103602DOI Listing
May 2021

Cough hypersensitivity and suppression in COPD.

Eur Respir J 2021 05 20;57(5). Epub 2021 May 20.

Centre for Human and Applied Physiological Sciences, School of Basic and Medical Biosciences, King's College London, London, UK

Cough reflex hypersensitivity and impaired cough suppression are features of chronic refractory cough (CRC). Little is known about cough suppression and cough reflex hypersensitivity in cough associated with chronic obstructive pulmonary disease (COPD). This study investigated the ability of patients with COPD to suppress cough during a cough challenge test in comparison to patients with CRC and healthy subjects. This study also investigated whether cough reflex hypersensitivity is associated with chronic cough in COPD.Participants with COPD (n=27) and CRC (n=11) and healthy subjects (n=13) underwent capsaicin challenge tests with and without attempts to self-suppress cough in a randomised order over two visits, 5 days apart. For patients with COPD, the presence of self-reported chronic cough was documented, and objective 24-h cough frequency was measured.Amongst patients with COPD, those with chronic cough (n=16) demonstrated heightened cough reflex sensitivity compared to those without chronic cough (n=11): geometric mean±sd capsaicin dose thresholds for five coughs (C5) 3.36±6.88 µmol·L 44.50±5.90 µmol·L, respectively (p=0.003). Participants with CRC also had heightened cough reflex sensitivity compared to healthy participants: geometric mean±sd C5 3.86±5.13 µmol·L 45.89±3.95 µmol·L, respectively (p<0.001). Participants with COPD were able to suppress capsaicin-evoked cough, regardless of the presence or absence of chronic cough: geometric mean±sd capsaicin dose thresholds for 5 coughs without self-suppression attempts (C5) and with (CS5) were 3.36±6.88 µmol·L 12.80±8.33 µmol·L (p<0.001) and 44.50±5.90 µmol·L 183.2±6.37 µmol·L (p=0.006), respectively. This was also the case for healthy participants (C5 CS5: 45.89±3.95 µmol·L 254.40±3.78 µmol·L, p=0.033), but not those with CRC, who were unable to suppress capsaicin-evoked cough (C5 CS5: 3.86±5.13 µmol·L 3.34±5.04 µmol·L, p=0.922). C5 and CS5 were associated with objective 24-h cough frequency in patients with COPD: ρ= -0.430, p=0.036 and ρ= -0.420, p=0.041, respectively.Patients with COPD-chronic cough and CRC both had heightened cough reflex sensitivity but only patients with CRC were unable to suppress capsaicin-evoked cough. This suggests differing mechanisms of cough between patients with COPD and CRC, and the need for disease-specific approaches to its management.
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http://dx.doi.org/10.1183/13993003.03569-2020DOI Listing
May 2021

Provision of holistic care after severe COVID-19 pneumonia: anticipating clinical need and managing resources.

Lancet Respir Med 2020 12 13;8(12):1175-1176. Epub 2020 Nov 13.

Centre for Human and Applied Physiological Sciences, King's College London, London WC2R 2LS, UK; Department of Respiratory Medicine, King's College Hospital NHS Foundation Trust, London, UK. Electronic address:

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http://dx.doi.org/10.1016/S2213-2600(20)30529-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7834100PMC
December 2020

Spatial Distribution of Normal Lung Sounds in Healthy Individuals under Varied Inspiratory Load and Flow Conditions.

Annu Int Conf IEEE Eng Med Biol Soc 2020 07;2020:2744-2747

Respiratory sounds yield pertinent information about respiratory function in both health and disease. Normal lung sound intensity is a characteristic that correlates well with airflow and it can therefore be used to quantify the airflow changes and limitations imposed by respiratory diseases. The dual aims of this study are firstly to establish whether previously reported asymmetries in normal lung sound intensity are affected by varying the inspiratory threshold load or the airflow of respiration, and secondly to investigate whether fixed sample entropy can be used as a valid measure of lung sound intensity. Respiratory sounds were acquired from twelve healthy individuals using four contact microphones on the posterior skin surface during an inspiratory threshold loading protocol and a varying airflow protocol. The spatial distribution of the normal lung sounds intensity was examined. During the protocols explored here the normal lung sound intensity in the left and right lungs in healthy populations was found to be similar, with asymmetries of less than 3 dB. This agrees with values reported in other studies. The fixed sample entropy of the respiratory sound signal was also calculated and compared with the gold standard root mean square representation of lung sound intensity showing good agreement.
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http://dx.doi.org/10.1109/EMBC44109.2020.9175992DOI Listing
July 2020

Performance Evaluation of Fixed Sample Entropy for Lung Sound Intensity Estimation.

Annu Int Conf IEEE Eng Med Biol Soc 2020 07;2020:2740-2743

Lung sound (LS) signals are often contaminated by impulsive artifacts that complicate the estimation of lung sound intensity (LSI) using conventional amplitude estimators. Fixed sample entropy (fSampEn) has proven to be robust to cardiac artifacts in myographic respiratory signals. Similarly, fSampEn is expected to be robust to artifacts in LS signals, thus providing accurate LSI estimates. However, the choice of fSampEn parameters depends on the application and fSampEn has not previously been applied to LS signals. This study aimed to perform an evaluation of the performance of the most relevant fSampEn parameters on LS signals, and to propose optimal fSampEn parameters for LSI estimation. Different combinations of fSampEn parameters were analyzed in LS signals recorded in a heterogeneous population of healthy subjects and chronic obstructive pulmonary disease patients during loaded breathing. The performance of fSampEn was assessed by means of its cross-covariance with flow signals, and optimal fSampEn parameters for LSI estimation were proposed.
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http://dx.doi.org/10.1109/EMBC44109.2020.9176215DOI Listing
July 2020

The Relationship Between Cough Reflex Sensitivity and Exacerbation Frequency in Chronic Obstructive Pulmonary Disease.

Lung 2020 08 19;198(4):617-628. Epub 2020 Jun 19.

Centre for Human and Applied Physiological Sciences, School of Basic and Medical Biosciences, King's College London, London, UK.

Background: Cough is predictive of exacerbations of chronic obstructive pulmonary disease (COPD). Little is known about cough reflex sensitivity during exacerbation of COPD and whether it is associated with exacerbation frequency. This pilot study aimed to investigate cough reflex sensitivity during and following recovery from exacerbation of COPD, and its association with the frequency of future exacerbations. In addition, the repeatability of cough reflex sensitivity in stable COPD was investigated.

Methods: Twenty participants hospitalised with exacerbation of COPD underwent inhaled capsaicin challenge during exacerbation and after 6 weeks of recovery. The frequency of future exacerbations was monitored for 12 months. The repeatability of cough reflex sensitivity was assessed in separate participants with stable COPD, who underwent 2 capsaicin challenge tests, 6 weeks apart.

Results: Cough reflex sensitivity was heightened during exacerbation of COPD. Geometric mean (SD) capsaicin concentration thresholds to elicit 5 coughs (C5) during exacerbation and after 6 weeks of recovery were 1.76 (3.73) vs. 8.09 (6.25) μmol L, respectively (p < 0.001). The change in C5 from exacerbation to 6-week recovery was associated with the frequency of future exacerbations (ρ = - 0.687, p = 0.003). C5 was highly repeatable over 6 weeks in stable COPD, and intraclass correlation coefficient was 0.85.

Conclusion: Cough reflex sensitivity is heightened during exacerbation of COPD and reduces after recovery. The persistence of cough reflex hypersensitivity at recovery was associated with the frequency of future exacerbations.
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http://dx.doi.org/10.1007/s00408-020-00366-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7374441PMC
August 2020

Heroin-induced respiratory depression and the influence of dose variation: within-subject between-session changes following dose reduction.

Addiction 2020 10 11;115(10):1954-1959. Epub 2020 Mar 11.

King's College London, National Addiction Centre, Institute of Psychiatry, Psychology and Neuroscience, London, UK.

Background And Aims: Globally, more than 100 000 people die annually from opioid overdose. Opportunities to study physiological events in at-risk individuals are limited. This study examined variation of opioid dose and impact on respiratory depression in a chronic injecting heroin user at separate time-points during his long-term diamorphine maintenance treatment.

Design: A single-subject study over 5 years during which participant underwent experimental studies on diamorphine-induced respiratory depression, at changing maintenance doses.

Setting: A clinical research facility. Participant Male subject on long-term injectable diamorphine (pharmaceutical heroin) maintenance treatment for heroin addiction.

Measurements: Physiological measures of oxygen saturation (SpO ), end-tidal carbon dioxide (ETCO ) and respiratory rate (RR) were used to indicate severity of respiratory depression.

Findings: (1) After diamorphine injection, respiratory regulation became abnormal, with prolonged apnoea exceeding 20 sec (maximum 56 sec), elevated ETCO (maximum 6.9%) and hypoxaemia (minimum SpO 80%). (2) Abnormalities were greater with highest diamorphine dose: average SpO was 89.3% after 100 mg diamorphine versus 93.6% and 92.8% for the two 30-mg doses. (3) However, long apnoeic pauses and high levels of ETCO % were also present after lower doses.

Conclusions: With marked inter-session variability, these findings corroborate observations of inconsistent relationships between opioid dose and overdose risk.
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http://dx.doi.org/10.1111/add.15014DOI Listing
October 2020

Control of exercise hyperpnoea: Contributions from thin-fibre skeletal muscle afferents.

Exp Physiol 2019 11 6;104(11):1605-1621. Epub 2019 Oct 6.

School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, UK.

New Findings: What is the topic of this review? In this review, we examine the evidence for control mechanisms underlying exercise hyperpnoea, giving attention to the feedback from thin-fibre skeletal muscle afferents, and highlight the frequently conflicting findings and difficulties encountered by researchers using a variety of experimental models. What advances does it highlight? There has been a recent resurgence of interest in the role of skeletal muscle afferent involvement, not only as a mechanism of healthy exercise hyperpnoea but also in the manifestation of breathlessness and exercise intolerance in chronic disease.

Abstract: The ventilatory response to dynamic submaximal exercise is immediate and proportional to metabolic rate, which maintains isocapnia. How these respiratory responses are controlled remains poorly understood, given that the most tightly controlled variable (arterial partial pressure of CO /H ) provides no error signal for arterial chemoreceptors to trigger reflex increases in ventilation. This review discusses evidence for different postulated control mechanisms, with a focus on the feedback from group III/IV skeletal muscle mechanosensitive and metabosensitive afferents. This concept is attractive, because the stimulation of muscle mechanoreceptors might account for the immediate increase in ventilation at the onset of exercise, and signals from metaboreceptors might be proportional to metabolic rate. A variety of experimental models have been used to establish the contribution of thin-fibre muscle afferents in ventilatory control during exercise, with equivocal results. The inhibition of afferent feedback via the application of lumbar intrathecal fentanyl during exercise suppresses ventilation, which provides the most compelling supportive evidence to date. However, stimulation of afferent feedback at rest has no consistent effect on respiratory output. However, evidence is emerging for synergistic interactions between muscle afferent feedback and other stimulatory inputs to the central respiratory neuronal pool. These seemingly hyperadditive effects might explain the conflicting findings encountered when using different experimental models. We also discuss the increasing evidence that patients with certain chronic diseases exhibit exaggerated muscle afferent activation during exercise, resulting in enhanced cardiorespiratory responses. This might provide a neural link between the well-established limb muscle dysfunction and the associated exercise intolerance and exertional dyspnoea, which might offer therapeutic targets for these patients.
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http://dx.doi.org/10.1113/EP087649DOI Listing
November 2019

Physical Inactivity in Pulmonary Sarcoidosis.

Lung 2019 06 19;197(3):285-293. Epub 2019 Mar 19.

Centre for Human and Applied Physiological Sciences, School of Basic and Medical Biosciences, King's College London, London, UK.

Purpose: Reduced physical activity in many chronic diseases is consistently associated with increased morbidity. Little is known about physical activity in sarcoidosis. The aim of this study was to objectively assess physical activity in patients with pulmonary sarcoidosis and investigate its relationship with lung function, exercise capacity, symptom burden, and health status.

Methods: Physical activity was assessed over one week in 15 patients with pulmonary sarcoidosis and 14 age-matched healthy controls with a tri-axial accelerometer (ActivPal™) and the International Physical Activity Questionnaire (IPAQ). All participants underwent pulmonary function tests, 6-min walk test (6MWT) and completed the Fatigue Assessment Scale (FAS), Medical Research Council (MRC) Dyspnoea Scale and the King's Sarcoidosis Questionnaire (KSQ).

Results: Patients with sarcoidosis had significantly lower daily step counts than healthy controls; mean (SD) 5624 (1875) versus 10,429 (2942) steps (p < 0.01) and a trend towards fewer sit-to-stand transitions each day (p = 0.095). Only two patients (13%) self-reported undertaking vigorous physical activity (IPAQ) compared to half of healthy individuals (p < 0.01). Daily step count was significantly associated with 6MWT distance in sarcoidosis (r = 0.634, p = 0.01), but not with forced vital capacity (r = 0.290), fatigue (r = 0.041), dyspnoea (r = -0.466) or KSQ health status (r = 0.099-0.484). Time spent upright was associated with fatigue (r = -0.630, p = 0.012) and health status (KSQ Lung scores r = 0.524, p = 0.045), and there was a significant correlation between the number of sit-to-stand transitions and MRC dyspnoea score (r = -0.527, p = 0.044).

Conclusion: Physical activity is significantly reduced in sarcoidosis and is associated with reduced functional exercise capacity (6MWD). Fatigue, exertional symptoms and health status were more closely associated with time spent upright and the number of bouts of physical activity, as compared to step counts. Further studies are warranted to identify the factors that determine different physical activity profiles in sarcoidosis.
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http://dx.doi.org/10.1007/s00408-019-00215-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6520325PMC
June 2019

Impaired cough suppression in chronic refractory cough.

Eur Respir J 2019 05 2;53(5). Epub 2019 May 2.

Centre for Human and Applied Physiological Sciences, School of Basic and Medical Biosciences, King's College London, London, UK.

Functional brain imaging in individuals with chronic cough demonstrates reduced activation in cortical regions associated with voluntary cough suppression. Little is known about the ability of patients with chronic cough to suppress cough. This study aimed to compare the ability to voluntarily suppress cough during inhaled capsaicin challenge in participants with chronic refractory cough with that in healthy controls. In addition, this study aimed to assess the repeatability of capsaicin challenge test with voluntary cough suppression.Participants with chronic refractory cough and healthy controls underwent inhaled capsaicin challenge tests while attempting to suppress their cough responses. After 5 days, either a conventional capsaicin challenge test with no cough suppression attempt, or a repeat test with an attempt at cough suppression was performed. Threshold capsaicin concentrations required to elicit one, two and five coughs were calculated by interpolation. Objective 24-h cough frequency was measured in individuals with chronic refractory cough.Healthy controls were able to suppress capsaicin-evoked cough while participants with chronic refractory cough were not. Geometric mean±sd capsaicin dose thresholds for five coughs with (CS5) and without (C5) suppression attempts were 254.40±3.78 45.89±3.95 µmol·L, respectively, in healthy controls (p=0.033) and 3.34±5.04 3.86±5.13 µmol·L, respectively, in participants with chronic refractory cough (p=0.922). Capsaicin dose thresholds for triggering five coughs with self-attempted cough suppression were significantly lower in participants with chronic refractory cough than in healthy controls; geometric mean±sd 4.94±4.43 261.10±4.34 µmol·L, respectively; mean difference (95% CI) 5.72 (4.54-6.91) doubling doses (p<0.001). Repeatability of cough suppression test in both patients and healthy controls was high; intraclass correlation coefficients of log(CS5) values 0.81 and 0.87, respectively. CS5 was associated with objective cough frequency (ρ=-0.514, p=0.029).Participants with chronic refractory cough were less able to voluntarily suppress capsaicin-evoked cough compared to healthy controls. This may have important implications for the pathophysiology and treatment of chronic cough.
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http://dx.doi.org/10.1183/13993003.02203-2018DOI Listing
May 2019

Surface mechanomyography and electromyography provide non-invasive indices of inspiratory muscle force and activation in healthy subjects.

Sci Rep 2018 11 16;8(1):16921. Epub 2018 Nov 16.

King's College Hospital NHS Foundation Trust, King's Health Partners, London, United Kingdom.

The current gold standard assessment of human inspiratory muscle function involves using invasive measures of transdiaphragmatic pressure (P) or crural diaphragm electromyography (oesEMG). Mechanomyography is a non-invasive measure of muscle vibration associated with muscle contraction. Surface electromyogram and mechanomyogram, recorded transcutaneously using sensors placed over the lower intercostal spaces (sEMG and sMMG respectively), have been proposed to provide non-invasive indices of inspiratory muscle activation, but have not been directly compared to gold standard P and oesEMG measures during voluntary respiratory manoeuvres. To validate the non-invasive techniques, the relationships between P and sMMG, and between oesEMG and sEMG were measured simultaneously in 12 healthy subjects during an incremental inspiratory threshold loading protocol. Myographic signals were analysed using fixed sample entropy (fSampEn), which is less influenced by cardiac artefacts than conventional root mean square. Strong correlations were observed between: mean P and mean fSampEn |sMMG| (left, 0.76; right, 0.81), the time-integrals of the P and fSampEn |sMMG| (left, 0.78; right, 0.83), and mean fSampEn oesEMG and mean fSampEn sEMG (left, 0.84; right, 0.83). These findings suggest that sMMG and sEMG could provide useful non-invasive alternatives to P and oesEMG for the assessment of inspiratory muscle function in health and disease.
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http://dx.doi.org/10.1038/s41598-018-35024-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6240075PMC
November 2018

Assessment of Inspiratory Muscle Activation using Surface Diaphragm Mechanomyography and Crural Diaphragm Electromyography.

Annu Int Conf IEEE Eng Med Biol Soc 2018 Jul;2018:3342-3345

The relationship between surface diaphragm mechanomyography (sMMGdi), as a noninvasive measure of inspiratory muscle mechanical activation, and crural diaphragm electromyography (oesEMGdi), as the invasive gold standard measure of diaphragm electrical activation, had not previously been examined. To investigate this relationship, oesEMGdi and sMMGdi were measured simultaneously in 6 healthy subjects during an incremental inspiratory threshold loading protocol, and analyzed using fixed sample entropy (fSampEn). A positive curvilinear relationship was observed between mean fSampEn sMMGdi and oesEMGdi (r = 0.67). Accordingly, an increasing electromechanical ratio was also observed with increasing inspiratory load. These findings suggest that sMMGdi could provide useful noninvasive measures of inspiratory muscle mechanical activation.
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http://dx.doi.org/10.1109/EMBC.2018.8513046DOI Listing
July 2018

A Cost-Effectiveness Analysis of Stop Smoking Interventions in Substance-Use Disorder Populations.

Nicotine Tob Res 2019 04;21(5):623-630

Addictions Department, Institute of Psychiatry, Psychology & Neuroscience, King's College London, UK.

Background: Tobacco smoking is highly prevalent among people attending treatment for a substance-use disorder (SUD). In the United Kingdom, specialist support to stop smoking is largely delivered by a national network of stop smoking services, and typically comprises of behavioral support delivered by trained practitioners on an individual (one-to-one) or group basis combined with a pharmacological smoking-cessation aid. We evaluate the cost-effectiveness of these interventions and compare cost-effectiveness for interventions using group- and individual-based support, in populations under treatment for SUD.

Methods: Economic modeling was used to evaluate the incremental cost-per-quality-adjusted-life-years (QALYs) gained for smoking-cessation interventions compared with alternative methods of quitting for the SUD treatment population. Allowance was made for potentially lower abstinence rates in the SUD population.

Results: The incremental cost-per-QALY gained from quit attempts supported through more frequently provided interventions in England ranged from around £4,700 to £12,200. These values are below the maximum cost-effectiveness threshold adopted by policy makers in England for judging whether health programs are a cost-effective use of resources. The estimated cost-per-QALY gained for interventions using group-based behavioral support were estimated to be at least half the magnitude of those using individual support due to lower intervention costs and higher reported quit rates. Conclusions reached regarding the cost-effectiveness of group-based interventions were also found to be more robust to changes in modeling assumptions.

Conclusions: Smoking-cessation interventions were found to be cost-effective when applied to the SUD population, particularly when group-based behavioral support is offered alongside pharmacological treatment.

Implications: This analysis has shown that smoking-cessation interventions combining pharmacological treatment with behavioral support can offer a cost-effective method for increasing rates of smoking cessation in populations being treated for a substance-use disorder. This is despite evidence of lower comparative success rates in terms of smoking abstinence in populations with SUD. Our evaluation suggests that medication combined with group-based behavioral support may offer better value for money in this population compared with interventions using individual support, though further evidence on the comparative effectiveness and cost of interventions delivered to SUD treatment populations would facilitate a more robust comparison.
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http://dx.doi.org/10.1093/ntr/nty087DOI Listing
April 2019

Increased respiratory neural drive and work of breathing in exercise-induced laryngeal obstruction.

J Appl Physiol (1985) 2018 02 2;124(2):356-363. Epub 2017 Nov 2.

Department of Respiratory Medicine, Royal Brompton Hospital , London , United Kingdom.

Exercise-induced laryngeal obstruction (EILO), a phenomenon in which the larynx closes inappropriately during physical activity, is a prevalent cause of exertional dyspnea in young individuals. The physiological ventilatory impact of EILO and its relationship to dyspnea are poorly understood. The objective of this study was to evaluate exercise-related changes in laryngeal aperture on ventilation, pulmonary mechanics, and respiratory neural drive. We prospectively evaluated 12 subjects (6 with EILO and 6 healthy age- and gender-matched controls). Subjects underwent baseline spirometry and a symptom-limited incremental exercise test with simultaneous and synchronized recording of endoscopic video and gastric, esophageal, and transdiaphragmatic pressures, diaphragm electromyography, and respiratory airflow. The EILO and control groups had similar peak work rates and minute ventilation (V̇e) (work rate: 227 ± 35 vs. 237 ± 35 W; V̇e: 103 ± 20 vs. 98 ± 23 l/min; P > 0.05). At submaximal work rates (140-240 W), subjects with EILO demonstrated increased work of breathing ( P < 0.05) and respiratory neural drive ( P < 0.05), developing in close temporal association with onset of endoscopic evidence of laryngeal closure ( P < 0.05). Unexpectedly, a ventilatory increase ( P < 0.05), driven by augmented tidal volume ( P < 0.05), was seen in subjects with EILO before the onset of laryngeal closure; there were however no differences in dyspnea intensity between groups. Using simultaneous measurements of respiratory mechanics and diaphragm electromyography with endoscopic video, we demonstrate, for the first time, increased work of breathing and respiratory neural drive in association with the development of EILO. Future detailed investigations are now needed to understand the role of upper airway closure in causing exertional dyspnea and exercise limitation. NEW & NOTEWORTHY Exercise-induced laryngeal obstruction is a prevalent cause of exertional dyspnea in young individuals; yet, how laryngeal closure affects breathing is unknown. In this study we synchronized endoscopic video with respiratory physiological measurements, thus providing the first detailed commensurate assessment of respiratory mechanics and neural drive in relation to laryngeal closure. Laryngeal closure was associated with increased work of breathing and respiratory neural drive preceded by an augmented tidal volume and a rise in minute ventilation.
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http://dx.doi.org/10.1152/japplphysiol.00691.2017DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5867370PMC
February 2018

New drug targets for chronic cough: research you can literally sink your teeth into!

Eur Respir J 2017 09 20;50(3). Epub 2017 Sep 20.

Dept of Respiratory Medicine, King's College Hospital NHS Foundation Trust, King's Health Partners, London, UK.

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http://dx.doi.org/10.1183/13993003.01571-2017DOI Listing
September 2017

Observational Study of Neural Respiratory Drive During Sleep at High Altitude.

High Alt Med Biol 2017 Sep 19;18(3):242-248. Epub 2017 Jun 19.

1 Faculty of Life Sciences and Medicine, King's College London , London, United Kingdom .

Steier, Joerg, Nic Cade, Ben Walker, John Moxham, and Caroline Jolley. Observational study of neural respiratory drive during sleep at high altitude. High Alt Med Biol. 18:242-248, 2017.

Aims: Ventilation at altitude changes due to altered levels of pO, pCO and the effect on blood pH. Nocturnal ventilation is particularly exposed to these changes. We hypothesized that an increasing neural respiratory drive (NRD) is associated with the severity of sleep-disordered breathing at altitude.

Methods: Mountaineers were studied at sea level (London, United Kingdom), and at altitude at the Aconcagua (Andes, Argentina). NRD was measured as electromyogram of the diaphragm (EMGdi) overnight by a transesophageal multi-electrode catheter; results were reported for sea level, 3,380 m, 4,370 m, and 5,570 m.

Results: Four healthy subjects (3 men, age 31(3)years, body mass index 23.6(0.9)kg/m, neck circumference 37.0(2.7)cm, forced expiratory volume in 1 second 111.8(5.1)%predicted, and forced vital capacity 115.5(6.3)%predicted) were studied. No subject had significant sleep abnormalities at sea level. Time to ascent to 3,380 m was 1 day, to 4,370 m was 5 days, and the total nights at altitude were 21 days. The oxygen desaturation index (4% oxygen desaturation index [ODI] 0.8(0.4), 22.0 (7.2), 61.4 (26.9), 144.9/hour, respectively) and the EMGdi (5.2 (1.9), 12.8 (5.1), 14.1 (3.4), 18.5%, respectively) increased with the development of periodic breathing at altitude, whereas the average SpO declined (97.5 (1.3), 84.8 (0.5), 81.0 (4.1), 68.5%, respectively). The average EMGdi correlated well with the 4%ODI (r = 0.968, p = 0.032).

Conclusion: NRD sleep increases at altitude in relation to the severity of periodic breathing.
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http://dx.doi.org/10.1089/ham.2016.0097DOI Listing
September 2017

ACE and response to pulmonary rehabilitation in COPD: two observational studies.

BMJ Open Respir Res 2017 8;4(1):e000165. Epub 2017 Mar 8.

NIHR Respiratory Biomedical Research Unit , Royal Brompton and Harefield NHS Foundation Trust and Imperial College , London , UK.

Introduction: Skeletal muscle impairment is an important feature of chronic obstructive pulmonary disease (COPD). Renin-angiotensin system activity influences muscle phenotype, so we wished to investigate whether it affects the response to pulmonary rehabilitation.

Methods: Two studies are described; in the first, the response of 168 COPD patients (mean forced expiratory volume in one second 51.9% predicted) to pulmonary rehabilitation was compared between different ACE insertion/deletion polymorphism genotypes. In a second, independent COPD cohort (n=373), baseline characteristics and response to pulmonary rehabilitation were compared between COPD patients who were or were not taking ACE inhibitors or angiotensin receptor antagonists (ARB).

Results: In study 1, the incremental shuttle walk distance improved to a similar extent in all three genotypes; DD/ID/II (n=48/91/29) 69(67)m, 61 (76)m and 78 (78)m, respectively, (p>0.05). In study 2, fat free mass index was higher in those on ACE-I/ARB (n=130) than those who were not (n=243), 17.8 (16.0, 19.8) kg m vs 16.5 (14.9, 18.4) kg/m (p<0.001). However change in fat free mass, walking distance or quality of life in response to pulmonary rehabilitation did not differ between groups.

Conclusions: While these data support a positive association of ACE-I/ARB treatment and body composition in COPD, neither treatment to reduce ACE activity nor ACE (I/D) genotype influence response to pulmonary rehabilitation.
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http://dx.doi.org/10.1136/bmjresp-2016-000165DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5353252PMC
March 2017

Variations in the cost of formal and informal health care for patients with advanced chronic disease and refractory breathlessness: A cross-sectional secondary analysis.

Palliat Med 2017 04 13;31(4):369-377. Epub 2017 Feb 13.

1 Cicely Saunders Institute, Department of Palliative Care, Policy and Rehabilitation, King's College London, London, UK.

Background: Refractory breathlessness in advanced chronic disease leads to high levels of disability, anxiety and social isolation. These result in high health-resource use, although this is not quantified.

Aims: To measure the cost of care for patients with advanced disease and refractory breathlessness and to identify factors associated with high costs.

Design: A cross-sectional secondary analysis of data from a randomised controlled trial.

Setting/participants: Patients with advanced chronic disease and refractory breathlessness recruited from three National Health Service hospitals and via general practitioners in South London.

Results: Of 105 patients recruited, the mean cost of formal care was £3253 (standard deviation £3652) for 3 months. The largest contributions to formal-care cost were hospital admissions (>60%), and palliative care contributed <1%. When informal care was included, the total cost increased by >250% to £11,507 (standard deviation £9911). Increased patient disability resulting from breathlessness was associated with high cost (£629 per unit increase in disability score; p = 0.006). Increased breathlessness on exertion and the presence of an informal carer were also significantly associated with high cost. Patients with chronic obstructive pulmonary disease tended to have higher healthcare costs than other patients.

Conclusion: Informal carers contribute significantly to the care of patients with advanced disease and refractory breathlessness. Disability resulting from breathlessness is an important clinical cost driver. It is important for policy makers to support and acknowledge the contributions of informal carers. Further research is required to assess the clinical- and cost-effectiveness of palliative care interventions in reducing disability resulting from breathlessness in this patient group.
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http://dx.doi.org/10.1177/0269216317690994DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5405827PMC
April 2017

Breathlessness during daily activity: The psychometric properties of the London Chest Activity of Daily Living Scale in patients with advanced disease and refractory breathlessness.

Palliat Med 2017 Oct 15;31(9):868-875. Epub 2016 Dec 15.

1 Department of Palliative Care, Policy and Rehabilitation, Cicely Saunders Institute, King's College London, London, UK.

Background: The London Chest Activities of Daily Living Scale measures the impact of breathlessness on both activity and social functioning. However, the London Chest Activities of Daily Living Scale is not routinely used in patients with advanced disease.

Aim: To assess the psychometric properties of the London Chest Activities of Daily Living Scale in patients with refractory breathlessness due to advanced disease.

Design: A cross-sectional secondary analysis of data from a randomised controlled parallel-group, pragmatic, single-blind fast-track trial (randomised controlled trial) investigating the effectiveness of an integrated palliative and respiratory care service for patients with advanced disease and refractory breathlessness, known as the Breathlessness Support Service (NCT01165034). All patients completed the following questionnaires: the London Chest Activities of Daily Living Scale, Chronic Respiratory Questionnaire, the Palliative care Outcome Scale, Palliative care Outcome Scale-symptoms, the Hospital Anxiety and Depression Scale and breathlessness measured on a numerical rating scale. Data quality, scaling assumptions, acceptability, internal consistency and construct validity of the London Chest Activities of Daily Living Scale were determined using standard psychometric approaches.

Setting/participants: Breathless patients with advanced malignant and non-malignant disease.

Results: A total of 88 patients were studied, primary diagnosis included; chronic obstructive pulmonary disease = 53, interstitial lung disease = 17, cancer = 18. Median (range) London Chest Activities of Daily Living Scale total score was 46.5 (14-67). No floor or ceiling effect was observed for the London Chest Activities of Daily Living Scale total score. Internal consistency was good, and Cronbach's alpha for the London Chest Activities of Daily Living Scale total score was 0.90. Construct validity was good with 13 out of 15 a priori hypotheses met.

Conclusion: Psychometric analyses suggest that the London Chest Activities of Daily Living Scale is acceptable, reliable and valid in patients with advanced disease and refractory breathlessness.
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http://dx.doi.org/10.1177/0269216316680314DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5613804PMC
October 2017

Physiological markers of exercise capacity and lung disease severity in cystic fibrosis.

Respirology 2017 05 24;22(4):714-720. Epub 2016 Nov 24.

Division of Asthma, Allergy and Lung Biology, Department of Respiratory Medicine (Chest Unit), King's College London, London, UK.

Background And Objective: Peak aerobic capacity (VO peak) is an important outcome measure in cystic fibrosis (CF), but measurement is not widely available and can be influenced by patient motivation, pain and fatigue. Alternative markers of disease severity would be helpful. Neural respiratory drive, measured using parasternal intercostal muscle electromyography (EMGpara), reflects the load to capacity balance of the respiratory system and provides a composite measure of pulmonary function impairment in CF. The aim of the study was to investigate the relationship between exercise capacity, EMGpara and established measures of pulmonary function in clinically stable adult CF patients.

Methods: Twenty CF patients (12 males, median (range) age: 22.3 (17.0-43.1) years) performed the 10-m incremental shuttle walk test (ISWT) maximally with contemporaneous measures of aerobic metabolism. EMGpara was recorded from second intercostal space at rest and normalized using peak electromyogram activity obtained during maximum respiratory manoeuvres and expressed as EMGpara%max (EMGpara expressed as a percentage of maximum).

Results: VO peak was strongly correlated with ISWT distance (r = 0.864, P < 0.0001). Lung gas transfer (T CO) % predicted was best correlated with VO peak (r = 0.842, P < 0.0001) and ISWT distance (r = 0.788, P < 0.0001). EMGpara%max also correlated with VO peak (-0.757, P < 0.0001), while the relationships between exercise outcome measures and forced expiratory volume in 1 s (FEV ) % predicted and forced vital capacity (FVC) % predicted were less strong. A T CO% predicted of <70.5% was the strongest predictor of VO peak <32 mL/min/kg (area under the curve (AUC): 0.96, 100% sensitivity, 83.3% specificity). ISWT distance and EMGpara%max also performed well, with other pulmonary function variables demonstrating poorer predictive ability.

Conclusion: T CO% predicted and EMGpara%max relate strongly to exercise performance markers in CF and may provide alternative predictors of lung disease progression.
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http://dx.doi.org/10.1111/resp.12954DOI Listing
May 2017

Dignity Through Integrated Symptom Management: Lessons From the Breathlessness Support Service.

J Pain Symptom Manage 2016 10 17;52(4):515-524. Epub 2016 Sep 17.

Department of Palliative Care, Policy & Rehabilitation, King's College London, Cicely Saunders Institute, London, UK.

Context: Dignity is poorly conceptualized and little empirically explored in end-of-life care. A qualitative evaluation of a service offering integrated palliative and respiratory care for patients with advanced disease and refractory breathlessness uncovered an unexpected outcome, it enhanced patients' dignity.

Objectives: To analyze what constitutes dignity for people suffering from refractory breathlessness with advanced disease, and its implications for the concept of dignity.

Methods: Qualitative study of cross-sectional interviews with 20 patients as part of a Phase III evaluation of a randomized controlled fast-track trial. The interviews were transcribed verbatim, imported into NVivo, and analyzed through constant comparison. The findings were compared with Chochinov et al.'s dignity model. The model was adapted with the themes and subthemes specific to patients suffering from breathlessness.

Results: The findings of this study underscore the applicability of the conceptual model of dignity for patients with breathlessness. There were many similarities in themes and subthemes. Differences specifically relevant for patients suffering from severe breathlessness were as follows: 1) physical distress and psychological mechanisms are interlinked with the disability and dependence breathlessness causes, in the illness-related concerns, 2) stigma is an important component of the social dignity inventory, 3) conditions and perspectives need to be present to practice self-care in the dignity-conserving repertoire.

Conclusion: Dignity is an integrated concept and can be affected by influences from other areas such as illness-related concerns. The intervention shows that targeting the symptom holistically and equipping patients with the means for self-care realized the outcome of dignity.
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http://dx.doi.org/10.1016/j.jpainsymman.2016.04.010DOI Listing
October 2016
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