Psychological aspects in the perception of dyspnea in obstructive pulmonary diseases

Significant burden of post-COVID exertional dyspnoea in a South-Italy region: knowledge of risk factors might prevent further critical overload on the healthcare system

Background

Exertional dyspnoea in post-COVID syndrome is a debilitating manifestation, requiring appropriate comprehensive management. However, limited-resources healthcare systems might be unable to expand their healthcare-providing capacity and are expected to be overwhelmed by increasing healthcare demand. Furthermore, since post-COVID exertional dyspnoea is regarded to represent an umbrella term, encompassing several clinical conditions, stratification of patients with post-COVID exertional dyspnoea, depending on risk factors and underlying aetiologies might provide useful for healthcare optimization and potentially help relieve healthcare service from overload. Hence, we aimed to investigate the frequency, functional characterization, and predictors of post-COVID exertional dyspnoea in a large cohort of post-COVID patients in Apulia, Italy, at 3-month post-acute SARS-CoV-2 infection.

Methods

A cohort of laboratory-confirmed 318 patients, both domiciliary or hospitalized, was evaluated in a post-COVID Unit outpatient setting. Post-COVID exertional dyspnoea and other post-COVID syndrome manifestations were collected by medical history. Functional characterization of post-COVID exertional dyspnoea was performed through a 6-min walking test (6-mwt). The association of post-COVID exertional dyspnoea with possible risk factors was investigated through univariate and multivariate logistic regression analysis.

Results

At medical evaluation, post-COVID exertional dyspnoea was reported by as many as 190/318 patients (59.7%), showing relatively high prevalence also in domiciliary-course patients. However, functional characterization disclosed a 6-mwt-based desaturation walking drop in only 24.1% of instrumental post-COVID exertional dyspnoea patients. Multivariate analysis identified five independent predictors significantly contributing to PCED, namely post-COVID-fatigue, pre-existing respiratory co-morbidities, non-asthmatic allergy history, age, and acute-phase-dyspnoea. Sex-restricted multivariate analysis identified a differential risk pattern for males (pre-existing respiratory co-morbidities, age, acute-phase-dyspnoea) and females (post-COVID-fatigue and acute-phase-dyspnoea).

Conclusion

Our findings revealed that post-COVID exertional dyspnoea is characterized by relevant clinical burden, with potential further strain on healthcare systems, already weakened by pandemic waves. Sex-based subgroup analysis reveals sex-specific dyspnoea-underlying risk profiles and pathogenic mechanisms. Knowledge of sex-specific risk-determining factors might help optimize personalized care management and healthcare resources.

Automatic Detection of Dyspnea in Real Human-Robot Interaction Scenarios

A respiratory distress estimation technique for telephony previously proposed by the authors is adapted and evaluated in real static and dynamic HRI scenarios. The system is evaluated with a telephone dataset re-recorded using the robotic platform designed and implemented for this study. In addition, the original telephone training data are modified using an environmental model that incorporates natural robot-generated and external noise sources and reverberant effects using room impulse responses (RIRs). The results indicate that the average accuracy and AUC are just 0.4% less than those obtained with matched training/testing conditions with simulated data. Quite surprisingly, there is not much difference in accuracy and AUC between static and dynamic HRI conditions. Moreover, the beamforming methods delay-and-sum and MVDR lead to average improvement in accuracy and AUC equal to 8% and 2%, respectively, when applied to training and testing data. Regarding the complementarity of time-dependent and time-independent features, the combination of both types of classifiers provides the best joint accuracy and AUC score.

Illness Perceptions, Cognitions, and Beliefs on COPD Patients' Adherence to Treatment - A Systematic Review

Background

Chronic Obstructive Pulmonary Disease (COPD) is a chronic inflammatory lung disease characterized by persistent respiratory symptoms and airflow limitation. Besides its irreversibility, COPD is a treatable condition, and patients would strongly benefit from being adherent to their treatments. However, almost half of them are non-adherent, and, according to several recent studies, the way the patient perceives the disease might influence this variable.

Aim

This systematic review provided a synthesis of studies about the relationships between illness perceptions (IP), cognitions, beliefs, and adherence in COPD.

Methods

English language publications were searched in PubMed, Medline, Scopus, ResearchGate, PsycINFO, and Cochrane Library databases from November 2022 to February 2023, following PRISMA guidelines. The reference lists of eligible studies were also searched. Data extraction and critical appraisal were undertaken by two reviewers working independently.

Results

A total of 14 studies were included. Adherence to treatment in COPD is confirmed to be low, using both self-report questionnaires and objective assessment systems. Most studies concluded that COPD is perceived as a moderate threat destined to last forever, even if many participants referred to little disease knowledge. This perception did not change between adherent and non-adherent groups. Those who considered more necessary to take their medicines and had a caregiver were more adherent and less concerned about their future. On the other side, forgetfulness, lack of trust in medications, and difficulties in understanding how to take them were perceived as the main causes of non-adherence. Other predictors of non-adherence, like depression, low self-efficacy, and severity of disease were confirmed.

Conclusion

The systematic review highlights the variability of the relationship between IP, cognitions and beliefs, and COPD treatment adherence. A new level of awareness of the relationship between patients' subjective point of view and treatment adherence may inform future treatment options and promote a more personalized intervention.

Dyspnea Severity Assessment Based on Vocalization Behavior with Deep Learning on the Telephone

In this paper, a system to assess dyspnea with the mMRC scale, on the phone, via deep learning, is proposed. The method is based on modeling the spontaneous behavior of subjects while pronouncing controlled phonetization. These vocalizations were designed, or chosen, to deal with the stationary noise suppression of cellular handsets, to provoke different rates of exhaled air, and to stimulate different levels of fluency. Time-independent and time-dependent engineered features were proposed and selected, and a k-fold scheme with double validation was adopted to select the models with the greatest potential for generalization. Moreover, score fusion methods were also investigated to optimize the complementarity of the controlled phonetizations and features that were engineered and selected. The results reported here were obtained from 104 participants, where 34 corresponded to healthy individuals and 70 were patients with respiratory conditions. The subjects' vocalizations were recorded with a telephone call (i.e., with an IVR server). The system provided an accuracy of 59% (i.e., estimating the correct mMRC), a root mean square error equal to 0.98, false positive rate of 6%, false negative rate of 11%, and an area under the ROC curve equal to 0.97. Finally, a prototype was developed and implemented, with an ASR-based automatic segmentation scheme, to estimate dyspnea on line.

Breathlessness and exercise with virtual reality system in long-post-coronavirus disease 2019 patients

Long-post-coronavirus disease-2019 (COVID-19) patients tend to claim residual symptomatology from various systems, most importantly the respiratory and central nervous systems. Breathlessness and brain fog are the main complaints. The pulmonary function pattern is consistent with restrictive defects, which, in most cases, are self-resolved, while the cognitive profile may be impaired. Rehabilitation is an ongoing field for holistic management of long-post-COVID-19 patients. Virtual reality (VR) applications may represent an innovative implementation of rehabilitation. We aimed to investigate the effect of exercise with and without the VR system and to assess further breathlessness and functional fitness indicators in long-post-COVID-19 patients with mild cognitive impairment after self-selected exercise duration using the VR system. Twenty long-post-COVID-19 patients were enrolled in our study (age: 53.9 ± 9.1 years, male: 80%, body mass index: 28.1 ± 3.1 kg/m²). Participants' anthropometric data were recorded, and they underwent pulmonary functional test evaluation as well as sleep quality and cognitive assessment. The participants randomly exercised with and without a VR system (VR vs. no-VR) and, later, self-selected the exercise duration using the VR system. The results showed that exercise with VR resulted in a lower dyspnea score than exercise without VR. In conclusion, VR applications seem to be an attractive and safe tool for implementing rehabilitation. They can enhance performance during exercise and benefit patients with both respiratory and cognitive symptoms.

Interventions for palliative symptom control in COVID-19 patients

BACKGROUND

Individuals dying of coronavirus disease 2019 (COVID-19) may experience distressing symptoms such as breathlessness or delirium. Palliative symptom management can alleviate symptoms and improve the quality of life of patients. Various treatment options such as opioids or breathing techniques have been discussed for use in COVID-19 patients. However, guidance on symptom management of COVID-19 patients in palliative care has often been derived from clinical experiences and guidelines for the treatment of patients with other illnesses. An understanding of the effectiveness of pharmacological and non-pharmacological palliative interventions to manage specific symptoms of COVID-19 patients is required.

OBJECTIVES

To assess the efficacy and safety of pharmacological and non-pharmacological interventions for palliative symptom control in individuals with COVID-19.

SEARCH METHODS

We searched the Cochrane COVID-19 Study Register (including Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (PubMed), Embase, ClinicalTrials.gov, World Health Organization International Clinical Trials Registry Platform (WHO ICTRP), medRxiv); Web of Science Core Collection (Science Citation Index Expanded, Emerging Sources); CINAHL; WHO COVID-19 Global literature on coronavirus disease; and COAP Living Evidence on COVID-19 to identify completed and ongoing studies without language restrictions until 23 March 2021. We screened the reference lists of relevant review articles and current treatment guidelines for further literature.

SELECTION CRITERIA

We followed standard Cochrane methodology as outlined in the Cochrane Handbook for Systematic Reviews of Interventions. We included studies evaluating palliative symptom management for individuals with a confirmed diagnosis of COVID-19 receiving interventions for palliative symptom control, with no restrictions regarding comorbidities, age, gender, or ethnicity. Interventions comprised pharmacological as well as non-pharmacological treatment (e.g. acupressure, physical therapy, relaxation, or breathing techniques). We searched for the following types of studies: randomized controlled trials (RCT), quasi-RCTs, controlled clinical trials, controlled before-after studies, interrupted time series (with comparison group), prospective cohort studies, retrospective cohort studies, (nested) case-control studies, and cross-sectional studies. We searched for studies comparing pharmacological and non-pharmacological interventions for palliative symptom control with standard care. We excluded studies evaluating palliative interventions for symptoms caused by other terminal illnesses. If studies enrolled populations with or exposed to multiple diseases, we would only include these if the authors provided subgroup data for individuals with COVID-19. We excluded studies investigating interventions for symptom control in a curative setting, for example patients receiving life-prolonging therapies such as invasive ventilation.  DATA COLLECTION AND ANALYSIS: We used a modified version of the Newcastle Ottawa Scale for non-randomized studies of interventions (NRSIs) to assess bias in the included studies. We included the following outcomes: symptom relief (primary outcome); quality of life; symptom burden; satisfaction of patients, caregivers, and relatives; serious adverse events; and grade 3 to 4 adverse events. We rated the certainty of evidence using the GRADE approach.  As meta-analysis was not possible, we used tabulation to synthesize the studies and histograms to display the outcomes.  MAIN RESULTS: Overall, we identified four uncontrolled retrospective cohort studies investigating pharmacological interventions for palliative symptom control in hospitalized patients and patients in nursing homes. None of the studies included a comparator. We rated the risk of bias high across all studies. We rated the certainty of the evidence as very low for the primary outcome symptom relief, downgrading mainly for high risk of bias due to confounding and unblinded outcome assessors. Pharmacological interventions for palliative symptom control We identified four uncontrolled retrospective cohort studies (five references) investigating pharmacological interventions for palliative symptom control. Two references used the same register to form their cohorts, and study investigators confirmed a partial overlap of participants. We therefore do not know the exact number of participants, but individual reports included 61 to 2105 participants. Participants received multimodal pharmacological interventions: opioids, neuroleptics, anticholinergics, and benzodiazepines for relieving dyspnea (breathlessness), delirium, anxiety, pain, audible upper airway secretions, respiratory secretions, nausea, cough, and unspecified symptoms.  Primary outcome: symptom relief All identified studies reported this outcome. For all symptoms (dyspnea, delirium, anxiety, pain, audible upper airway secretions, respiratory secretions, nausea, cough, and unspecified symptoms), a majority of interventions were rated as completely or partially effective by outcome assessors (treating clinicians or nursing staff). Interventions used in the studies were opioids, neuroleptics, anticholinergics, and benzodiazepines.  We are very uncertain about the effect of pharmacological interventions on symptom relief (very low-certainty evidence). The initial rating of the certainty of evidence was low since we only identified uncontrolled NRSIs. Our main reason for downgrading the certainty of evidence was high risk of bias due to confounding and unblinded outcome assessors. We therefore did not find evidence to confidently support or refute whether pharmacological interventions may be effective for palliative symptom relief in COVID-19 patients. Secondary outcomes We planned to include the following outcomes: quality of life; symptom burden; satisfaction of patients, caregivers, and relatives; serious adverse events; and grade 3 to 4 adverse events. We did not find any data for these outcomes, or any other information on the efficacy and safety of used interventions. Non-pharmacological interventions for palliative symptom control None of the identified studies used non-pharmacological interventions for palliative symptom control.

AUTHORS' CONCLUSIONS

We found very low certainty evidence for the efficacy of pharmacological interventions for palliative symptom relief in COVID-19 patients. We found no evidence on the safety of pharmacological interventions or efficacy and safety of non-pharmacological interventions for palliative symptom control in COVID-19 patients. The evidence presented here has no specific implications for palliative symptom control in COVID-19 patients because we cannot draw any conclusions about the effectiveness or safety based on the identified evidence. More evidence is needed to guide clinicians, nursing staff, and caregivers when treating symptoms of COVID-19 patients at the end of life. Specifically, future studies ought to investigate palliative symptom control in prospectively registered studies, using an active-controlled setting, assess patient-reported outcomes, and clearly define interventions. The publication of the results of ongoing studies will necessitate an update of this review. The conclusions of an updated review could differ from those of the present review and may allow for a better judgement regarding pharmacological and non-pharmacological interventions for palliative symptom control in COVID-19 patients.

The breathing brain: The potential of neural oscillations for the understanding of respiratory perception in health and disease

Dyspnea or breathlessness is a symptom occurring in multiple acute and chronic illnesses, however, the understanding of the neural mechanisms underlying its subjective experience is limited. In this topical review, we propose neural oscillatory dynamics and cross-frequency coupling as viable candidates for a neural mechanism underlying respiratory perception, and a technique warranting more attention in respiration research. With the evidence for the potential of neural oscillations in the study of normal and disordered breathing coming from disparate research fields with a limited history of interdisciplinary collaboration, the main objective of the review was to converge the existing research and suggest future directions. The existing findings show that distinct limbic and cortical activations, as measured by hemodynamic responses, underlie dyspnea, however, the time-scale of these activations is not well understood. The recent findings of oscillatory neural activity coupled with the respiratory rhythm could provide the solution to this problem, however, more research with a focus on dyspnea is needed. We also touch on the findings of distinct spectral patterns underlying the changes in breathing due to experimental manipulations, meditation and disease. Subsequently, we suggest general research directions and specific research designs to supplement the current knowledge using neural oscillation techniques. We argue for the benefits of interdisciplinary collaboration and the converging of neuroimaging and behavioral methods to best explain the emergence of the subjective and aversive individual experience of dyspnea.

Anxiety sensitivity and respiratory disease outcomes among individuals with chronic obstructive pulmonary disease

OBJECTIVE

Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality worldwide. Depression and anxiety worsen COPD and lead to greater respiratory symptom severity and health care utilization. Fear of physical sensations of anxiety (AS-P) is known to exacerbate respiratory symptoms. The current study investigated the unique contribution of AS-P in respiratory symptom exacerbations, emergency department visits, hospitalizations, and COPD-related functional health status, controlling for medical characteristics, depression, and anxiety.

METHOD

The sample included 535 adults with COPD (M_age = 56.57; 58.1% male). Participants were recruited from a web-based panel of adults with chronic respiratory disease and completed an online battery of self-report measures.

RESULTS

Consistent with hypotheses, AS-P significantly increased the likelihood of acute symptom exacerbations by 12% and respiratory-related emergency department visits and hospitalizations by 7% during the prior 12 month period. Additionally, AS-P demonstrated a unique, large effect (f² = 0.37) on COPD-related functional health status.

CONCLUSION

Fear of physical sensations contributed to worse respiratory outcomes and health care utilization among adults with COPD. Screening for AS-P may effectively identify at-risk COPD patients, while reducing AS-P through targeted interventions may result in decreased symptom severity, functional limitations, and burden on the health care system.

Cross-modal relationships of neural gating with the subjective perception of respiratory and somatosensory sensations

Neural gating is a phenomenon whereby the response to a stimulus in the electroencephalogram (EEG) is attenuated when preceded by an identical stimulus. Attenuation of paired auditory clicks has repeatedly been shown to be affected in mental disorders, for example, schizophrenia. Neural gating has also been measured for respiratory and somatosensory sensations, however the attenuation of bodily relevant stimuli has not yet been systematically related to the subjective perception of bodily sensations. This research direction is potentially relevant to explaining disease trajectories in psychosomatic conditions characterized by chronic breathlessness and/or pain. In the present study, we recorded high-density EEG from 85 healthy young adults while they experienced brief paired respiratory occlusions and brief paired electrocutaneous stimulation of the wrist. The event-related potential N1 was measured centro-laterally in response to the second relative to the first stimulus to quantify neural gating in both sensory domains. Participants experienced resistive loaded breaths and electrocutaneous stimuli of various intensities, rated their perceived intensity and unpleasantness, and performed magnitude estimation. Relationships of respiratory and somatosensory neural gating to the subjective intensity and unpleasantness of sensations, as well as the ability to discriminate sensations of varying intensities, were investigated intra-modally and cross-modally. We report significant relationships of the somatosensory neural gating to perceived intensity and unpleasantness of respiratory and somatosensory sensations, with the stronger neural gating relating to a stronger subjective intensity and unpleasantness. We discuss these unexpected findings through the lens of individual differences and different theoretical accounts on the origins of cortical attenuation of repetitive stimuli.

Factors associated with discrepancies between poor dyspnea perception and abnormal lung function in 65 asthmatic patients

Background

Dyspnea is a subjective symptom of asthma whose perception is characterized by an interindividual variability. Poor dyspnea perception is usually associated with increased risk of exacerbation and may lead to inappropriate asthma management and under-treatment. We sought to identify factors associated with discrepancies between poor dyspnea perception and abnormal lung function in patients with moderate persistent asthma.

Methodology

65 patients, who attended their scheduled follow-up pulmonology consultation at Ibn Sina Hospital (Rabat - Morocco), underwent interrogation including modified Medical Research Council (mMRC) scale for dyspnea, physical examination and spirometry. Two groups, those with mMRC < 2 (poor dyspnea perceivers) and those with mMRC scale ≥ 2 were compared.

Results

Poor dyspnea perception was found in 21 patients (32.3%). Associated factors were male sex (p : 0.03), low socio-economic income (p : 0.01), an onset of symptoms greater than 10 years (p : 0.01), BMI ≥ 25 Kg/m2 (p : 0.04) and depression (p : 0.04).

Conclusion

The results revealed factors significantly associated with poor dyspnea perception despite an obstructive ventilatory disorder. These factors could usefully be considered to successfully manage asthma as well as the regular prescription of an objective test like spirometry.

Low-intensity educational interventions supporting self-management to improve outcomes related to chronic breathlessness: a systematic review

Chronic breathlessness is debilitating and frightening, often resulting in emergency department presentations with acute-on-chronic breathlessness. Self-management is complex, involving 14 components as identified by the Practical Systematic Review in Self-Management Support (PRISMS). Low-intensity educational interventions that support breathlessness self-management through written/visual educational materials, alongside limited health professional support, are available. Our aim was to describe components of low-intensity educational interventions that support and improve self-management for adults with chronic breathlessness and evaluate their efficacy for improving breathlessness-related outcomes. A systematic review was conducted, including RCTs that compared these interventions with usual care in adults with chronic disease. Synthesis took a narrative approach utilizing the PRISMS taxonomy and Template for Intervention Description and Replication (TIDieR) checklist. Of the 1948 articles identified, 7 met criteria reporting 7 RCTs using 6 interventions. Studies utilized 12 out of 14 PRISMS components, the most frequent being training/rehearsal for psychological strategies. Evidence for effectiveness was inconsistent and attempts to identify beneficial components were confounded by intervention complexity and heterogeneity. The optimal content and delivery of low-intensity educational interventions that support self-management to improve chronic breathlessness-related outcomes in adults cannot be defined from current published literature. Future research should incorporate more detailed, standardized reporting to enable comparison and meta-analysis.

Respiratory modulation of intensity ratings and psychomotor response times to acoustic startle stimuli

Respiratory interoception may play an important role in the perception of respiratory symptoms in pulmonary diseases. As the respiratory cycle affects startle eye blink responses, startle modulation may be used to assess visceral-afferent signals from the respiratory system. To ascertain the potential impact of brainstem-relayed signals on cortical processes, we investigated whether this pre-attentive respiratory modulation of startle (RMS) effect is also reflected in the modulation of higher cognitive, evaluative processing of the startle stimulus. Twenty-nine healthy volunteers received 80 acoustic startle stimuli (100 or 105 dB(A); 50 ms), which were presented at end and mid inspiration and expiration, while performing a paced breathing task (0.25 Hz). Participants first responded to the startle probes by 'as fast as possible' button pushes and then rated the perceived intensity of the stimuli. Psychomotor response time was divided into 'reaction time' (RT; from stimulus onset to home button release; represents stimulus evaluation) and 'movement time' time (MT; from home button release to target button press). Intensity judgments were higher and RTs accelerated during mid expiration. No effect of respiratory cycle phase was found on eye blink responses and MTs. We conclude that respiratory cycle phase affects higher cognitive, attentional processing of startle stimuli.

Symptoms and perception of airway obstruction in asthmatic patients: Clinical implications for use of reliever medications

BACKGROUND

Asthma causes the unpleasant sensation of breathlessness (dyspnea) caused by airway obstruction. Patients with poor perception of airway obstruction are at risk of delay in seeking medical attention and undertreatment, which can lead to avoidable deaths. Conversely, those with heightened perception are at risk of overtreatment and iatrogenic adverse effects with reliever medications, anxiety, and unnecessary use of health care resources.

OBJECTIVE

We sought to review evidence about symptom misperception in asthmatic patients and how to identify and manage affected patients, particularly with regard to reliever medications.

METHODS

We conducted a systematic literature search for studies of perception of airway function in asthmatic patients. We searched the OVID (Medline and Medline [R] in process [PubMed]), Embase, and Adisearch/Odyssey databases, restricting our search to human studies published in English from 1990-2018, with no restrictions on age, sex, or racial origin.

RESULTS

We found that both underperception and overperception assessed during induced bronchoconstriction or bronchodilation or during changes in airway resistance were common across all age groups and that aging, disease severity, smoking, sex, ethnicity, psychologic factors, and medication are all associated with differences in perception. Importantly, airway inflammation was associated with impaired perception and a history of severe or near-fatal asthma. We also identified knowledge gaps, such as whether an individual patient's perception varies over time and the influence perception has on patients' use of reliever medication.

CONCLUSION

We found that abnormal perception of airway obstruction has important clinical implications for the management of patients with asthma.

Implementation of a depression screening protocol among respiratory insufficiency patients

INTRODUCTION

Unnoticed and untreated depression is prevalent among patients with chronic respiratory insufficiency. Comorbid depression causes suffering and worsens patients' outcomes.

OBJECTIVES

The objective of this evaluation was to assess preliminary outcomes of a depression screening protocol among chronic respiratory insufficiency patients at a tertiary care pulmonary outpatient clinic.

METHODS

In the depression screening protocol, the patients filled the Depression Scale (DEPS) questionnaire. Patients whose scores suggested depression were offered the opportunity of a further evaluation of mood at a psychiatric outpatient clinic. The outcomes of the protocol were evaluated retrospectively from the patient records.

RESULTS

During the period of evaluation, 238 patients visited the outpatient clinic. DEPS was administered to 176 patients (74%), of whom 60 (34%) scored ≥9 (out of 30), thus exceeding the cut-off for referral. However, only 13 patients were referred, as the remainder declined the referral. Finally, seven patients were evaluated at the psychiatric clinic, and they all were deemed depressive. Symptoms of depression were most prevalent among patients with a long smoking history, refractory dyspnoea and a history of depression.

CONCLUSION

Depression screening was positive in a third of the patients. The depression screening protocol improved the detection of depression symptoms, but the effects on the patients' treatment and clinical course were small. Rather than referring patients to a psychiatric unit, the evaluation and management of depression should be undertaken at the pulmonary unit.

The Impact of Unpredictability on Dyspnea Perception, Anxiety and Interoceptive Error Processing

Dyspnea is a prevalent interoceptive sensation and the aversive cardinal symptom in many cardiorespiratory diseases as well as in mental disorders. Especially the unpredictability of the occurrence of dyspnea episodes has been suggested to be highly anxiety provoking for affected patients. Moreover, previous studies demonstrated that unpredictable exteroceptive stimuli increased self-reports and electrophysiological responses of anxiety such as the startle probe N100 as well as amplified the processing of errors as reflected by greater error-related negativity (ERN). However, studies directly examining the role of unpredictability on dyspnea perception, anxiety, and error processing are widely absent. Using high-density electroencephalography, the present study investigated whether unpredictable compared to predictable dyspnea would increase the perception of dyspnea, anxiety and interoceptive error processing. Thirty-two healthy participants performed a respiratory forced choice reaction time task to elicit an interoceptive ERN during two conditions: an unpredictable and a predictable resistive load-induced dyspnea condition. Predictability was manipulated by pairing (predictable condition) or not pairing (unpredictable condition) dyspnea with a startle tone probe. Self-reports of dyspnea and affective state as well as the startle probe N100 and interoceptive ERN were measured. The results demonstrated greater dyspnea unpleasantness in the unpredictable compared to the predictable condition. Post hoc analyses revealed that this was paralleled by greater anxiety, and greater amplitudes for the startle probe N100 and the interoceptive ERN during the unpredictable relative to the predictable condition, but only when the unpredictable condition was experienced in the first experimental block. Furthermore, higher trait-like anxiety sensitivity was associated with higher ratings for dyspnea unpleasantness and experimental state anxiety ratings. The present findings suggest that unpredictability increases the perception of dyspnea unpleasantness. This effect seems related to increased state and trait anxiety and interoceptive error processing, especially when upcoming dyspnea is particularly unpredictable, such as in early experimental phases. Future studies are required to further substantiate these findings in patients suffering from dyspnea.

The impact of disease-specific fears on outcome measures of pulmonary rehabilitation in patients with COPD

Anxiety is a highly prevalent psychological comorbidity in patients with chronic obstructive pulmonary disease (COPD) and has detrimental effects on pulmonary rehabilitation (PR) outcomes. It has been suggested that disease-specific fears could play an even more important role in COPD patients' disease progression. However, little is known about how different disease-specific fears impact COPD. This study examined how different disease-specific fears relate to different PR outcome measures in COPD patients and how these relationships evolve over the course of PR. Before and after a 3-week inpatient PR program, COPD patients (N = 104) underwent a 6-min walking test to measure functional exercise capacity. Disease-specific fears (fear of physical activity, fear of dyspnea, fear of disease progression, fear of social exclusion) were assessed with the COPD-Anxiety-Questionnaire-Revised. Health-related quality of life (HQoL), COPD health status, dyspnea in daily life, depression, and anxiety were measured using validated questionnaires. Multiple regression showed that greater disease-specific fears at the start of PR were associated with worse functional exercise capacity, HQoL, health status, and depression at the start and end of PR (controlling for age, sex, lung function, smoking status, and general anxiety). Patients who showed a stronger decrease in disease-specific fears improved more in PR outcome measures over the course of PR. Furthermore, different disease-specific fears were related to different PR outcome measures. The results show that disease-specific fears are associated with treatment outcome measures, both cross-sectionally and prospectively. Therefore, disease-specific fears should be addressed in COPD patients as they might play a significant role in disease progression.

Visceral-afferent signals from the cardiovascular system, but not urinary urge, affect startle eye blink

The aim of the current study was to investigate if startle methodology is suitable to reflect urinary urgency. Eighteen healthy men were tested on two separate days, each including an ingestion of fluid until 80% of the subjective urge to micturate was reached. EMG responses to acoustic startle stimuli were assessed before and after micturition, as well as in the early and late cardiac cycle phases (230 vs. 530 ms after a cardiac R-wave). Sonographic assessment confirmed bladder-filling status. Emotional arousal, stress, urge and unpleasantness ratings, as well as mean blood pressure were higher before than after micturition. Startle eye blink responses were lower during the early than during the late cardiac cycle phase, but were not affected by bladder filling status. We conclude that startle methodology is suitable for the investigation of afferent signals from the cardiovascular system, but not to reflect urinary urgency. This result may be due to different neurophysiological mechanisms underlying afferent signals from the bladder compared to other visceral organs or interference with affective states or sympathetic activation associated with bladder filling. Notwithstanding, the present research protocol of fluid intake, sonographic assessment of the bladder, and subjective reports, can be applied to examine effects of urinary urge on physiological and psychological processes.

The interrelations among aspects of dyspnea and symptoms of depression in COPD patients - a network analysis

BACKGROUND

Depression is a frequent comorbidity in COPD. COPD symptoms such as dyspnea may play an important role in the causal relationship between COPD and depression. We investigated the interrelations among different aspects of dyspnea and other COPD parameters and symptoms of depression in COPD patients.

METHODS

This is a secondary analysis of N = 590 COPD patients. At the beginning (T0) and the end (T1) of a 3-week inpatient pulmonary rehabilitation, dyspnea aspects intensity (BORG scale), frequency (2 CCQ items), functioning (CCQ-function) and cognitive/emotional response (2 SGRQ items) as well as cough (2 CCQ items), functional capacity (6MWD), lung function (FEV1) and symptoms of depression (PHQ-9) were assessed. Regression analyses with PHQ-9 sum score as dependent variable as well as network analysis using PHQ-9 single items were performed. Structural invariance over time was examined.

RESULTS

Dyspnea frequency, function, and cognitive/emotional response showed conditional independent relationships with PHQ-9 sum score. Network analysis showed that dyspnea frequency and dyspnea functioning were primarily associated with somatic depression symptoms (for example, sleep problems, loss of energy), while cognitive/emotional response was primarily related to cognitive-affective depression symptoms (for example, feeling down/depressed/hopeless). Regression parameters, network structure and network global strength did not differ between T0 and T1.

LIMITATIONS

Models are based on between-person relationships. Results should be confirmed using time-series data.

CONCLUSIONS

Dyspnea and depression seem to be interrelated through a variety of different and complex pathways in COPD patients. Results may be used to explain intervention effects and develop new intervention strategies to reduce depression in COPD.

Characterization and Triggers of Dyspnea in Patients with Chronic Obstructive Pulmonary Disease or Chronic Heart Failure: Effects of Weather and Environment

BACKGROUND AND OBJECTIVES

Dyspnea is one of the most disturbing symptoms for patients with chronic obstructive pulmonary disease (COPD) or heart failure (HF). This study investigated dyspnea triggers and factors associated with worsening dyspnea in patients with COPD or HF.

METHODS

COPD support group members and HF patients with reduced ejection fraction (HFrEF) and no airway obstruction answered a questionnaire describing different weather conditions (rising/falling air pressure, sunny, foggy, rainy, windy, snowy, hazy, high ozone levels, and airborne pollen) and environmental circumstances (cooking, grilling, perfumes, cigarette smoke, gasoline odor, and flower scents) and were asked to estimate the occurrence and severity of dyspnea under these conditions using predefined scales.

RESULTS

230 patients with COPD and 90 with HFrEF (left ventricular ejection fraction 34 ± 10%, Tiffeneau index > 70%) were analyzed. COPD patients reported dyspnea more often than HF patients in almost all weather and environmental conditions (p = 0.004 to p < 0.001), with the exception of outdoor floral scents and cigarette smoke. Severe to very severe dyspnea was reported more in COPD versus HF in all weather and environmental conditions except sunny weather (p = 0.01 to p < 0.001). COPD was associated with more severe dyspnea than HF in all conditions (all p < 0.001).

CONCLUSIONS

Dyspnea was triggered by a variety of weather and other environmental triggers in patients with COPD and occurred more often than in HF patients under the same conditions. Foggy weather and exposure to perfumes were associated with severe dyspnea in the majority of COPD patients, but only a minority of HF patients.

Evaluation of Dyspnea in the Elderly

Dyspnea is due to an imbalance between the demand to breathe and the ability to breathe. The prevalence is ∼30% for those 65 years or older with walking on a level surface or up an incline. Dyspnea is a strong predictor of mortality in elderly individuals. Anemia, cardiovascular disease, deconditioning, psychological disorders, and respiratory diseases are common causes of dyspnea. Initial treatments to relieve breathing discomfort should be directed toward improving the pathophysiology of the underlying disease. Simple and inexpensive strategies to relieve dyspnea are available. This article provides an update on the evaluation of chronic dyspnea in elderly individuals.

Association of anxiety sensitivity-physical concerns and FVC with dyspnea severity in sarcoidosis

OBJECTIVE

The purpose of the study was to evaluate the relationship of an objective functional lung parameter (FVC) and a subjective psychological factor (physical symptom concerns) with dyspnea in sarcoidosis. Dyspnea constitutes one of the most common and burdensome symptoms in sarcoidosis, yet little is known about its mechanisms and, in particular, psychological.

METHOD

A total of 107 hospitalized sarcoidosis patients (Female=50, M_age=45.3years) volunteered to take part in the correlational research study. Participants underwent spirometry and completed the MRC Dyspnea Scale and the Anxiety Sensitivity Index-3 (ASI) questionnaire. Linear hierarchical regression analysis was used to determine the relationship between the studied predictors and dyspnea severity.

RESULTS

The best fitting model predicted 18% of variance in dyspnea severity. Physical symptom concerns subscale of ASI (β=0.24) and FVC (β=-0.23) were significantly related to dyspnea MRC severity, but only physical concerns remained significantly related to dyspnea when both predictors were in the model.

CONCLUSIONS

The current results suggest that both psychological and physiological factors should be taken into account when explaining subjective dyspnea severity in sarcoidosis. More specifically, these findings call for including cognitive vulnerability factors related to anxiety (physical symptom concerns) into the diagnostic procedures and management of dyspnea in sarcoidosis.

Breathing SPACE-a practical approach to the breathless patient

Breathlessness is a common symptom that may have multiple causes in any one individual and causes that may change over time. Breathlessness campaigns encourage people to see their General Practitioner if they are unduly breathless. Members of the London Respiratory Network collaborated to develop a tool that would encourage a holistic approach to breathlessness, which was applicable both at the time of diagnosis and during ongoing management. This has led to the development of the aide memoire “Breathing SPACE”, which encompasses five key themes—smoking, pulmonary disease, anxiety/psychosocial factors, cardiac disease, and exercise/fitness. A particular concern was to ensure that high-value interventions (smoking cessation and exercise interventions) are prioritised across the life-course and throughout the course of disease management. The approach is relevant both to well people and in those with an underling diagnosis or diagnoses. The inclusion of anxiety draws attention to the importance of mental health issues. Parity of esteem requires the physical health problems of people with mental illness to be addressed. The SPACE mnemonic also addresses the problem of underdiagnosis of heart disease in people with lung disease and vice versa, as well as the systematic undertreatment of these conditions where they do co-occur.

Singing for Lung Health-a systematic review of the literature and consensus statement

There is growing interest in Singing for Lung Health (SLH), an approach where patients with respiratory disease take part in singing groups, intended to improve their condition. A consensus group was convened in early 2016 to address issues including: the specific features that make SLH distinct from other forms of participation in singing; the existing evidence base via a systematic review; gaps in the evidence base including the need to define value-based outcome measures for sustainable commissioning of SLH; defining the measures needed to evaluate both individuals' responses to SLH and the quality of singing programmes. and core training, expertise and competencies required by singing group leaders to deliver high-quality programmes. A systematic review to establish the extent of the evidence base for SLH was undertaken. Electronic databases, including Pubmed, OVID Medline and Embase, Web of Science, Cochrane central register of controlled trials and PEDro, were used. Six studies were included in the final review. Quantitative data suggest that singing has the potential to improve health-related quality of life, particularly related to physical health, and levels of anxiety without causing significant side effects. There is a significant risk of bias in many of the existing studies with small numbers of subjects overall. Little comparison can be made between studies owing to their heterogeneity in design. Qualitative data indicate that singing is an enjoyable experience for patients, who consistently report that it helps them to cope with their condition better. Larger and longer-term trials are needed.

Respiratory modulation of startle eye blink: a new approach to assess afferent signals from the respiratory system

Current approaches to assess interoception of respiratory functions cannot differentiate between the physiological basis of interoception, i.e. visceral-afferent signal processing, and the psychological process of attention focusing. Furthermore, they typically involve invasive procedures, e.g. induction of respiratory occlusions or the inhalation of CO₂-enriched air. The aim of this study was to test the capacity of startle methodology to reflect respiratory-related afferent signal processing, independent of invasive procedures. Forty-two healthy participants were tested in a spontaneous breathing and in a 0.25 Hz paced breathing condition. Acoustic startle noises of 105 dB(A) intensity (50 ms white noise) were presented with identical trial frequency at peak and on-going inspiration and expiration, based on a new pattern detection method, involving the online processing of the respiratory belt signal. The results show the highest startle magnitudes during on-going expiration compared with any other measurement points during the respiratory cycle, independent of whether breathing was spontaneous or paced. Afferent signals from slow adapting phasic pulmonary stretch receptors may be responsible for this effect. This study is the first to demonstrate startle modulation by respiration. These results offer the potential to apply startle methodology in the non-invasive testing of interoception-related aspects in respiratory psychophysiology.This article is part of the themed issue 'Interoception beyond homeostasis: affect, cognition and mental health'.

Common causes of dyspnoea in athletes: a practical approach for diagnosis and management

Key points

Educational aims

Dyspnoea during exercise is a common chief complaint in athletes and active individuals. It is not uncommon for dyspnoeic athletes to be diagnosed with asthma, “exercise-induced asthma” or exercise-induced bronchoconstriction based on their symptoms, but this strategy regularly leads to misdiagnosis and improper patient management. Dyspnoea during exercise can ultimately be caused by numerous respiratory and nonrespiratory conditions, ranging from nonpathological to potentially fatal in severity. As, such it is important for healthcare providers to be familiar with the many factors that can cause dyspnoea during exercise in seemingly otherwise-healthy individuals and have a general understanding of the clinical approach to this patient population. This article reviews common conditions that ultimately cause athletes to report dyspnoea and associated symptoms, and provides insight for developing an efficient diagnostic plan.

Dyspnoea, fatigue and underperformance are often interrelated symptoms in athletes, and may have various causeshttp://ow.ly/4nsYnk

A proportional assist ventilator to unload respiratory muscles experimentally during exercise in humans

What is the central question of this study? Can a modern proportional assist ventilator (PAV) function sufficiently well to unload the respiratory muscles during exercise? What is the main finding and its importance? A PAV can be constructed with contemporary hardware and software and be used at all exercise intensities to unload the respiratory muscles by up to 70%. Previously, PAVs have allowed researchers to address many fundamental physiological problems in clinical and healthy populations, but those versions are no longer functional or available. We describe the creation of a PAV that permits researchers to use it as an experimental tool. Manipulation of the normally occurring work of breathing (WOB) during exercise can provide insights into whole-body regulatory mechanisms in clinical patients and healthy subjects. One method to reduce the WOB uses a proportional assist ventilator (PAV). Suitable commercially available units are not capable of being used during heavy exercise. This investigation was undertaken in order to create a PAV and assess the degree to which the WOB could be reduced during exercise. A PAV works by creating a positive mouth pressure (Pm ) during inspiration, which consequently reduces the WOB. Spontaneous breathing patterns can be maintained, and the amplitude of Pm is calculated using the equation of motion and predetermined proportionality constants. We generated positive Pm using a breathing apparatus consisting of rigid tubing, solenoid valves to control the airflow direction and a proportional valve connected to compressed gas. Healthy male and female subjects were able to use the PAV successfully while performing cycling exercise over a range of intensities (50-100% of maximal workload) for different durations (from 30 s to 20 min) and different protocols (constant versus progressive workload). Inspiratory WOB was reduced up to 90%, while total WOB was reduced by 70%. The greatest reduction in WOB (50-75%) occurred during submaximal exercise, but at maximal ventilations (>180 l min(-1) ) a 50% reduction was still possible. The calculated change in WOB and subsequent reduction in respiratory muscle oxygen consumption resulted in equivalent reductions in whole-body oxygen consumption. With adequate familiarization and practice, our PAV can consistently reduce the WOB across a range of exercise intensities.

Being Anxious, Thinking Positively: The Effect of Emotional Context on Respiratory Sensory Gating

Respiratory sensory gating function has been found decreased by induced negative emotion in healthy adults. The increased ratio of the respiratory-related evoked potential (RREP) N1 peak amplitude for the second occlusion (S2) vs. the first occlusion (S1), S2/S1, is indicative of such decreased respiratory sensory gating. In this study, we tested the hypothesis that a positive emotional context would enhance respiratory sensory gating function in healthy individuals. In addition, we tested the modulating role of individual anxiety levels. We compared respiratory sensory gating in 40 healthy individuals by the paired inspiratory occlusion paradigm in a positive and neutral emotional context induced by emotional picture viewing. The results showed that the group averaged RREP N1 peak amplitudes S2/S1 ratios were significantly smaller in the positive compared to neutral context (0.49 vs. 0.64; p < 0.01). Further, analysis showed that the ratio decrease was due to a reduced response to the S2 and an enhanced response to S1 in the positive emotional context (p < 0.05). The subgroup analyses showed that in the positive emotional context, both individuals with low-moderate anxiety levels and those with no anxiety demonstrated a significant decrease of their S2/S1 ratio, but only those with low-moderate anxiety levels showed reduced S2 amplitudes compared to the neutral context (p < 0.01). In conclusion, our results suggest that a positive emotional context is related to better brain inhibitory mechanisms by filtering out repetitive respiratory stimuli in healthy individuals, especially in the presence of low-moderate anxiety levels. Further, investigation on how positive emotional contexts might contribute to improved respiratory sensory gating ability in clinical populations is necessary.

Prospective use of descriptors of dyspnea to diagnose common respiratory diseases

BACKGROUND

Although patients may find it difficult to describe their breathing discomfort, most are able to select statements among a list to describe their experience. The primary objective of this study was to examine sensitivity and specificity of descriptors of breathing discomfort prospectively in patients with common respiratory conditions as well as those patients who had refractory dyspnea.

METHODS

Outpatients answered "Yes" or "No" for each of 15 statements describing breathing discomfort, next selected the best three that most closely applied, and then completed the Hospital Anxiety Depression Scale-Anxiety subscale. Sensitivity, specificity, and predictive values were calculated for the descriptors by diagnosis.

RESULTS

"Work/effort" descriptors were selected as the best three by patients with COPD (n = 68), respiratory muscle weakness (n = 11), and refractory dyspnea (n = 17). Along with "work/effort" descriptors, "My chest feels tight" was among the best three in asthma (n = 22), with 38% sensitivity and 88% specificity. Along with "work/effort" descriptors, "My breathing is shallow" was among the best three in interstitial lung disease (n = 8), with 33% sensitivity and 84% specificity. Affective descriptors "frightening" (61% vs 31%, P = .002) and "awful" (66% vs 37%, P = .004) were reported more frequently in those with high anxiety scores compared with low anxiety scores.

CONCLUSIONS

Although no descriptor achieved satisfactory sensitivity and specificity for identifying a particular condition, chest "tightness" was unique for asthma, whereas "shallow breathing" was unique for interstitial lung disease. Affective descriptors were associated with high anxiety scores.

Development of a dyspnoea word cue set for studies of emotional processing in COPD

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The first cue-based task to explore recall of dyspnoea and dyspnoea-related anxiety in COPD.

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Patients’ dyspnoea and dyspnoea-anxiety ratings agreed with established measures of dyspnoea.

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Patients’ dyspnea-anxiety ratings changed in accordance with clinical improvement.

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The task was reliable and well tolerated.

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The task is suitable for FMRI use and may aid dyspnoea neuroimaging research.

Patients with chronic dyspnoea may learn to fear situations that cue dyspnoea onset. Such dyspnoea-specific cues may then cause anxiety, and worsen or trigger dyspnoea even before commencement of physical activity. We therefore developed an experimental tool to probe emotional processing of dyspnoea for use with neuroimaging in COPD. The tool consists of a computerised task comprising multiple presentations of dyspnoea-related word cues with subsequent rating of dyspnoea and dyspnoea-anxiety with a visual analogue scale. Following 3 development stages, sensitivity to clinical change was tested in 34 COPD patients undergoing pulmonary rehabilitation. We measured internal consistency, sensitivity to clinical change and convergence with established dyspnoea measures (including Dyspnoea-12). Cronbach’s alpha was 0.90 for dyspnoea and 0.94 for dyspnea-anxiety ratings. Ratings correlated with Dyspnoea-12 (dyspnoea: r = 0.51, P = 0.002; dyspnea-anxiety: r = 0.54, P = 0.001). Reductions in dyspnea-anxiety ratings following pulmonary rehabilitation correlated with reductions in Dyspnoea-12 (r = 0.51, P = 0.002). We conclude that the word-cue task is reliable, and is thus a potentially useful tool for neuroimaging dyspnoea research.

Respiratory sensory gating measured by respiratory-related evoked potentials in generalized anxiety disorder

The perception of respiratory sensations plays an important role both in respiratory diseases and in anxiety disorders. However, little is known about the neural processes underlying respiratory sensory perception, especially in patient groups. Therefore, the present study examined whether patients with generalized anxiety disorder (GAD) would demonstrate altered respiratory sensory gating compared to a healthy control group. Respiratory-related evoked potentials (RREP) were measured in a paired inspiratory occlusion paradigm presenting two brief occlusion stimuli (S1 and S2) within one inspiration. The results showed a significantly greater S2/S1 ratio for the N1 component of the RREP in the GAD group compared to the control group. Our findings suggest altered respiratory sensory processing in patients with GAD, which might contribute to altered perception of respiratory sensations in these patients.

Cognitive behaviour therapy reduces dyspnoea ratings in patients with chronic obstructive pulmonary disease (COPD)

There is evidence that psychological factors contribute to the perception of increased difficulty of breathing in patients with chronic obstructive pulmonary disease (COPD), and increase morbidity. We tested the hypothesis that cognitive behaviour therapy (CBT) decreases ratings of perceived dyspnoea in response to resistive loading in patients with COPD. From 31 patients with COPD, 18 were randomised to four sessions of specifically targeted CBT and 13 to routine care. Prior to randomisation, participants were tested with an inspiratory external resistive load protocol (loads between 5 and 45cmH2O/L/s). Six months later, we re-measured perceived dyspnoea in response to the same inspiratory resistive loads and compared results to measurements prior to randomisation. There was a significant 17% reduction in dyspnoea ratings across the loads for the CBT group, and no reduction for the routine care group. The decrease in ratings of dyspnoea suggests that CBT to alleviate breathing discomfort may have a role in the routine treatment of people with COPD.

Anxiety and depression are related to dyspnea and clinical control but not with thoracoabdominal mechanics in patients with COPD

OBJECTIVE

To investigate the relationship between the presence of symptoms of anxiety or depression with breathing pattern and thoracoabdominal mechanics at rest and during exercise in COPD.

METHODS

Cross-sectional study enrolled 54 patients with COPD ranked according to Hospital Anxiety and Depression Scale (HAD) score and compared to dyspnea, clinical control, hypercapnia, breathing pattern and thoracoabdominal mechanics at rest and during exercise.

RESULTS

Seventeen patients with COPD had no symptoms, 12 had anxiety symptoms, 13 had depressive symptoms and 12 had both symptoms. COPD with depressive symptoms presented greater degree of dyspnea (p<0.01). Poor clinical control was observed in COPD with anxious and/or depressive symptoms (p<0.05). Breathing pattern and thoracoabdominal mechanics were similar among all groups at rest and during exercise.

CONCLUSIONS

COPD with symptoms of depression report more dyspnea. Anxiety and depression are associated with poor clinical control without impact on breathing pattern and thoracoabdominal mechanics in COPD.

The effect of tracheal occlusion on respiratory load compensation: changes in neurons containing inhibitory neurotransmitter in the nucleus of the solitary tract in conscious rats

Respiratory load compensation volume-time (Vt-T) relationships have been extensively studied in anesthetized animals. There are only a few studies in conscious animals although consciousness and behavior play a critical role in modulation of breathing. The aims of the study were to determine the effect of intermittent and transient tracheal occlusions (ITTO) elicited load compensation responses and the changes in activation of inhibitory glycinergic neurons in the nucleus of solitary tract (NTS) in conscious rats. The results showed that ITTO elicited an increase in expiratory time (T(e)) but did not affect inspiratory time (T(i)) and diaphragm activity (EMG(dia)). An increase in total breathing time (Ttot) was due exclusively to the increase in T(e). In addition, glycinergic neurons were activated in the intermediate NTS (iNTS) but not in the caudal NTS (cNTS). These results suggest that the activated glycinergic neurons in the iNTS may be important for the neurogenesis of load compensation responses in conscious animals.

Patients with COPD with higher levels of anxiety are more physically active

BACKGROUND

Physical activity (PA) has been found to be an excellent predictor of mortality beyond traditional measures in COPD. We aimed to determine the association between depression and anxiety with accelerometry-based PA in patients with COPD.

METHODS

We performed a cross-sectional analysis of baseline data from 148 stable patients with COPD enrolled in an ongoing, longitudinal, observational study. We measured PA (total daily step count) with a Stepwatch Activity Monitor over 7 days, depression and anxiety with the Hospital Anxiety and Depression Scales (HADSs), dyspnea with the Shortness of Breath Questionnaire, and functional capacity with the 6-min walk test.

RESULTS

Increased anxiety was associated with higher levels of PA such that for every one-point increase in the HADS-Anxiety score there was a corresponding increase of 288 step counts per day (β=288 steps, P<.001), after adjusting for all other variables. Higher levels of depressive symptoms were associated with lower PA (β=-176 steps, P=.02) only when anxiety was in the model. The interaction term for anxiety and depression approached significance (β=26, P=.10), suggesting that higher levels of anxiety mitigate the negative effects of depression on PA.

CONCLUSIONS

The increased PA associated with anxiety in COPD is, to our knowledge, a novel finding. However, it is unclear whether anxious patients with COPD are more restless, and use increased psychomotor activity as a coping mechanism, or whether those with COPD who push themselves to be more physically active experience more anxiety symptoms. Future studies should evaluate for anxiety and PA to better inform how to improve clinical outcomes.

TRIAL REGISTRY

Clinicaltrials.gov; No.: NCT01074515; URL: www.clinicaltrials.gov.

The prospective association of perceived criticism with dyspnea in chronic lung disease

OBJECTIVE

Perceived criticism from family members influences mental health. The link between perceived criticism and physical health has not been thoroughly investigated. The objective of this study was to examine the association of perceived criticism with dyspnea in chronic obstructive pulmonary disease (COPD).

METHODS

401 individuals with alpha-1 antitrypsin deficiency-associated COPD completed questionnaires at baseline, 1- and 2-year follow-up. Perceived criticism at baseline was examined as a predictor of dyspnea at all three time points using a linear mixed model that adjusted for demographic and health characteristics.

RESULTS

There was an interaction between perceived criticism and psychological distress (p=0.038). Perceived criticism was associated with dyspnea only among individuals with elevated psychological distress (b=0.32, SE=0.13, p=0.018).

CONCLUSION

Further research is needed to replicate these findings and determine the extent to which they apply to other common subjective physical symptoms such as pain.

Emotions and neural processing of respiratory sensations investigated with respiratory-related evoked potentials

OBJECTIVE

Patients with respiratory diseases such as asthma and chronic obstructive pulmonary disease frequently experience respiratory sensations, which are often perceived as unpleasant or threatening. However, the accurate perception of respiratory sensations is important for the management and treatment of these diseases. Emotions can substantially influence the perception of respiratory sensations and might affect the course of respiratory diseases, but the underlying neural mechanisms are poorly understood. The respiratory-related evoked potential (RREP) recorded from the electroencephalogram is a noninvasive technique that allowed first studies to examine the impact of emotions on the neural processing of respiratory sensations.

METHODS

In this review, we will briefly introduce the importance of the perception of respiratory sensations and the influence of emotions on respiratory perception. We then provide an overview on the technique of RREP and present a systematic review on recent findings using this technique in the context of emotions.

RESULTS AND CONCLUSIONS

The evidence currently available from studies in healthy individuals suggests that short-lasting emotional states and anxiety affect the later RREP components (N1, P2, P3) related to higher-order neural processing of respiratory sensations, but not the earlier RREP components (Nf, P1) related to first-order sensory processing. We conclude with a discussion of the implications of this work for future research that needs to focus on respiratory patient groups and the associated clinical outcomes.

Psychosocial factors and behavioral medicine interventions in asthma

OBJECTIVE

This review examines the evidence for psychosocial influences in asthma and behavioral medicine approaches to its treatment.

METHOD

We conducted a systematic review of the literature on psychosocial influences and the evidence for behavioral interventions in asthma with a focus on research in the past 10 years and clinical trials. Additional attention was directed at promising new developments in the field.

RESULTS

Psychosocial factors can influence the pathogenesis and pathophysiology of asthma, either directly through autonomic, endocrine, immunological, and central nervous system mechanisms or indirectly through lifestyle factors, health behaviors, illness cognitions, and disease management, including medication adherence and trigger avoidance. The recent decade has witnessed surging interest in behavioral interventions that target the various pathways of influence. Among these, self-management training, breathing training, and exercise or physical activation programs have proved particularly useful, whereas other essential or promising interventions, such as smoking cessation, dietary programs, perception and biofeedback training, and suggestive or expressive psychotherapy, require further, more rigorous evaluation. Given the high comorbidity with anxiety and mood disorders, further evaluation of illness-specific cognitive behavior therapy is of particular importance. Progress has also been made in devising community-based and culturally tailored intervention programs.

CONCLUSION

In concert with an essential medication treatment, behavioral medicine treatment of asthma is moving closer toward an integrated biopsychosocial approach to disease management.

Neuromodulation and Palliative Medicine

The palliative care population is generally vulnerable to experiencing medication-induced adverse effects and drug–drug interactions. Neuromodulation may offer particular advantages over systemic medications in this population. Spinal cord stimulation and peripheral nerve stimulation have long been utilized in efforts to provide analgesia for various painful conditions. More recently, deep brain stimulation/motor cortex stimulation has anecdotally been utilized for certain intractable pain states. Although brain electrical stimulation has not been adequately trialed or in some cases even tried at all for management of a variety of symptoms, it is conceivable that in the future it may be a potential therapeutic option in efforts to palliate various severe refractory symptoms (eg, intractable pain, nausea, dyspnea, delirium).

The impact of emotion on the perception of graded magnitudes of respiratory resistive loads

Emotional state can modulate the perception of respiratory loads but the range of respiratory load magnitudes affected by emotional state is unknown. We hypothesized that viewing pleasant, neutral and unpleasant affective pictures would modulate the perception of respiratory loads of different load magnitudes. Twenty-four healthy adults participated in the study. Five inspiratory resistive loads of increasing magnitude (5, 10, 15, 20, 45 cm H(2)O/L/s) were repeatedly presented for one inspiration while participants viewed pleasant, neutral and unpleasant affective picture series. Participants rated how difficult it was to breathe against the load immediately after each presentation. Only at the lowest load, magnitude estimation ratings were greater when subjects viewed the unpleasant series compared to the neutral and pleasant series. These results suggest that negative emotional state increases the sense of respiratory effort for single presentations of a low magnitude resistive load but high magnitude loads are not further modulated by emotional state.

Dyspnea in hospitalized advanced cancer patients: subjective and physiologic correlates

BACKGROUND AND OBJECTIVE

It is unclear if physiologic measures are useful for assessing dyspnea. We examined the association among the subjective rating of dyspnea according to patients with advanced cancer, caregivers and nurses, and various physiologic measures.

METHODS

We conducted a cross-sectional survey of patients with cancer hospitalized at MD Anderson Cancer Center. We asked patients, caregivers, and nurses to assess the patients' dyspnea at the time of study enrollment independently using a numeric rating scale (0=none, 10=worst). Edmonton Symptom Assessment Scale (ESAS) ratings, causes of dyspnea, vitals, and Respiratory Distress Observation Scale [RDOS] ratings were collected.

RESULTS

A total of 299 patients were enrolled in the study: average age 62 (range 20-98), female 47%, lung cancer 37%, and oxygen use 57%. The median RDOS rating was 2/16 (interquartile range 1-3) and the number of potential causes was 3 (range 2-4), with pleural effusion (n=166, 56%), pneumonia (n=144, 48%), and lung metastasis (n=125, 42%) being the most common. The median intensity of patients' dyspnea at the time of assessment was 3 (interquartile range 0-6) for patients, 4 (interquartile range 1-6) for caregivers, and 2 (interquartile range 0-3) for bedside nurses. Patients' expression of dyspnea correlated moderately with caregivers' (r=0.68, p<0.001) and nurses' (r=0.50, p<0.001) assessments, and weakly with RDOS (r=0.35, p<0.001), oxygen level (r=0.32, p<0.001), and the number of potential causes (r=0.19, p=0.001). In multivariate analysis, patients' dyspnea was only independently associated with ESAS dyspnea (p=0.002) and dyspnea as assessed by caregivers (p<0.001).

CONCLUSION

Patients' level of dyspnea was weakly associated with physiologic measures. Caregivers' perception may be a useful surrogate for dyspnea assessment.

The impact of emotions on symptom perception in patients with asthma and healthy controls

Accurate perception of respiratory symptoms is highly important for course and treatment of asthma. Recent findings suggest that emotions can greatly impact respiratory symptom perception. This study compared the impact of emotions on respiratory symptom perception between patients with asthma and matched healthy controls. Pleasant and unpleasant emotional states were elicited by viewing emotional picture series while symptom reports and respiratory parameters were measured. Greater symptom report was observed for the unpleasant compared to the pleasant emotional state that was not related to respiratory parameters. Notably, this effect was comparable between patients with asthma and healthy controls. The present results suggest that the impact of emotions on respiratory symptom perception is a rather general phenomenon and not dependent upon previous experiences with asthma symptoms.