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

Evaluation of bronchial hyperresponsiveness in asthmatic paediatric patients using mannitol challenge test - Impacts of body mass index

BACKGROUND

Increasing epidemiological studies reported that overweight/obese asthma patients had more frequent and severe symptoms and exacerbations, indicating their asthma management may not be sufficient. Airway hyperresponsiveness (AHR), a significant feature of asthma, was found to link with the body mass index (BMI) with mixed findings using the "direct" methacholine challenge test. The objective was to examine the association between BMI and asthma control, as reflected by the "indirect" AHR with the mannitol challenge test in a paediatric asthmatic population.

METHODS

A total of 80 subjects with physician-diagnosed asthma, aged 6-18 years were enrolled in this cross-sectional study. Patients were first asked to complete the Asthma Control Test (ACT) questionnaire to self-evaluate their disease status. A mannitol challenge test was then performed to assess their AHR severity.

RESULTS

Seventy-six patients (96%) rated their asthma as well-controlled with an ACT score ≥ 20, but 42 patients (53%) were tested positive in the mannitol challenge test with mild and moderate AHR. While patients with mild AHR had comparable lung functions to those without AHR, patients with moderate AHR showed slightly but significantly lower FEV1 and FEV1/FVC values. Although no significant difference in the BMI values was noted for patients with different levels of AHR, the trend of increasing BMI with age was steeper for patients with moderate AHR.

CONCLUSION

A high prevalence of AHR (>50%) was found in asthmatic children who self-evaluated with good asthma control. No significant influence of the BMI on the AHR severity could be demonstrated in this population with the "indirect" mannitol challenge test. Since only a small number of overweight/obese subjects were recruited in the present study, further verification of the results with a larger sample size of obese subjects is required.

Sensory interventions to relieve dyspnoea in critically ill mechanically ventilated patients

BACKGROUND

In critically ill patients receiving mechanical ventilation, dyspnoea is frequent, severe and associated with an increased risk of neuropsychological sequelae. We evaluated the efficacy of sensory interventions targeting the brain rather than the respiratory system to relieve dyspnoea in mechanically ventilated patients.

METHODS

Patients receiving mechanical ventilation for ≥48 h and reporting dyspnoea (unidimensional dyspnoea visual analogue scale (Dyspnoea-VAS)) first underwent increased pressure support and then, in random order, auditory stimulation (relaxing music versus pink noise) and air flux stimulation (facial versus lower limb). Treatment responses were assessed using Dyspnoea-VAS, the Multidimensional Dyspnea Profile and measures of the neural drive to breathe (airway occlusion pressure (P 0.1) and electromyography of inspiratory muscles).

RESULTS

We included 46 patients (tracheotomy or intubation n=37; noninvasive ventilation n=9). Increasing pressure support decreased Dyspnoea-VAS by median 40 mm (p<0.001). Exposure to music decreased Dyspnoea-VAS compared with exposure to pink noise by median 40 mm (p<0.001). Exposure to facial air flux decreased Dyspnoea-VAS compared with limb air flux by median 30 mm (p<0.001). Increasing pressure support, but not music exposure and facial air flux, reduced P 0.1 by median 3.3 cmH2O (p<0.001).

CONCLUSIONS

In mechanically ventilated patients, sensory interventions can modulate the processing of respiratory signals by the brain irrespective of the intensity of the neural drive to breathe. It should therefore be possible to alleviate dyspnoea without resorting to pharmacological interventions or having to infringe the constraints of mechanical ventilation lung protection strategies by increasing ventilatory support.

Depressive Symptoms and Overperception of Airflow Obstruction in Older Adults With Asthma

OBJECTIVE

Older adults are at increased risk for depression and poor asthma outcomes. We examined whether depressive symptoms are associated with overperception of airflow obstruction and a pattern of worse asthma control, but not pulmonary function.

METHODS

We recruited a cohort of adults with asthma 60 years and older in East Harlem and the Bronx, New York. Baseline measures included the Geriatric Depression Scale, Asthma Control Questionnaire, and Mini Asthma Quality of Life Questionnaire. Spirometry was conducted at baseline to assess pulmonary function. Perception of airflow obstruction was assessed for 6 weeks following baseline by participants entering estimates of peak expiratory flow (PEF) into a programmable peak flow meter followed by PEF blows. Participants were blinded to actual PEF values. The percentage of time that participants were in the overperception zone was calculated as an average.

RESULTS

Among the 334 participants (51% Hispanic, 25% Black), depressive symptoms were associated with overperception of airflow obstruction (β = 0.14, p = .029), worse self-reported asthma control (β = 0.17, p = .003), and lower asthma-related quality of life (β = -0.33, p < .001), but not with lung function (β = -0.01, p = .82). Overperception was also associated with worse self-reported asthma control (β = 0.14, p = .021), but not lung function (β = -0.05, p = .41).

CONCLUSIONS

Depressive symptoms were associated with greater perceived impairment from asthma, but not pulmonary function. Overperception of asthma symptoms may play a key role in the relationship between depression and asthma outcomes in older adults.

Effects of Chemotherapy-Induced Peripheral Neuropathy in Women With Breast Cancer: A Structural Equation Approach With the Theory of Unpleasant Symptoms

BACKGROUND

Chemotherapy-induced peripheral neuropathy (CIPN) is a common neurotoxic effect. Chemotherapy-induced peripheral neuropathy symptoms have multidimensional characteristics that are associated with various physiologic, psychological, and situational factors and affect individual's abilities to effectively function in performing daily tasks. The theory of unpleasant symptoms mediates the relationships among CIPN symptom experience, reduced performance in daily tasks, and causative factors.

OBJECTIVES

The aim of this study was to examine how influencing factors (physiologic, psychological, and situational) affect CIPN symptoms and the impact of symptom experience on functional interference in daily activities of chemotherapy-treated breast cancer survivors.

METHODS

A cross-sectional survey about causative factors, CIPN symptoms, and functional interference was completed by 190 women treated with adjuvant chemotherapy for nonmetastatic breast cancer. The hypothetical model was tested using structural equation modeling analysis.

RESULTS

The proposed model provided a good fit to the data. Physiologic and psychological factors accounted for 25.5% of the variance in CIPN symptom experience and explained 37.1% of the variance interfering with functional performance through CIPN symptom experience.

CONCLUSION

Disease- and treatment-related physiologic factors and coexisting psychological distress play crucial roles in explaining CIPN symptom experience and daily function in breast cancer survivors.

IMPLICATIONS FOR PRACTICE

The findings help healthcare professionals to improve long-term care for breast cancer survivors in terms of education for self-monitoring, coping, and establishing supportive environment that can contribute to reducing the unmet needs and interference associated with persistent CIPN.

Psychometric evaluation of the Brazilian version of the pediatric asthma control and communication instrument

BACKGROUND

There is a lack of questionnaires capable of evaluating the clinical control of Brazilian children and adolescents with asthma over a wide age range. The Pediatric Asthma Control and Communication Instrument (PACCI) has been validated, but only with English- and Spanish-speaking children in the United States.

OBJECTIVES

To evaluate the psychometric properties of the Brazilian version of the PACCI questionnaire.

METHODS

A cross-sectional psychometric study conducted with children and adolescents aged 01 to 19 years with a clinical diagnosis of asthma, and their respective parents/guardians. The following assessments were conducted: socioeconomic status; clinical control using the Childhood Asthma Control Test (c-ACT), Asthma Control Test (ACT); caregiver quality of life using the Pediatric Asthma Caregivers Quality of Life Questionnaire (PACQLQ); and pulmonary function test (spirometry). Validity was evaluated as follows: exploratory and confirmatory factor analysis; Cronbach's alpha analysis (α); floor and ceiling effects; receiver operator characteristic curve analysis.

RESULTS

A total of 128 participants were included, most of them male (54.7%). The Brazilian version of PACCI had adequate internal consistency (α = .76) and moderate floor and ceiling effects. The internal structure presented acceptable adjustment indices, considering the extraction of four factors. The factors presented adequate α values. Asthma control factor 1 correlated with c-ACT/ACT and PACQLQ. Control domain scores greater than four points (sum of score) and above 1 point (problem index) were indicative of uncontrolled asthma.

CONCLUSION

The Brazilian version of PACCI was able to provide valid and reliable measures in evaluating the clinical control of asthma in Brazilian children and adolescents.

Breathlessness amplifies amygdala responses during affective processing

Breathlessness is an aversive symptom in many prevalent somatic and psychiatric diseases and is usually experienced as highly threatening. It is strongly associated with negative affect, but the underlying neural processes remain poorly understood. Therefore, using fMRI, the present study examined the effects of breathlessness on the neural processing of affective visual stimuli within candidate brain areas including the amygdala, insula, and anterior cingulate cortex (ACC). During scanning, 42 healthy volunteers, mean (SD) age: 29.0 (6.0) years, 14 female, were presented with affective picture series of negative, neutral, and positive valence while experiencing either no breathlessness (baseline conditions) or resistive-load induced breathlessness (breathlessness conditions). Respiratory measures and self-reports suggested successful induction of breathlessness and affective experiences. Self-reports of breathlessness intensity and unpleasantness were significantly higher during breathlessness conditions, mean (SD): 45.0 (16.6) and 32.3 (19.8), as compared to baseline conditions, mean (SD): 1.9 (3.0) and 2.9 (5.5). Compared to baseline conditions, stronger amygdala activations were observed during breathlessness conditions for both negative and positive affective picture series relative to neutral picture series, while no such effects were observed in insula and ACC. The present findings demonstrate that breathlessness amplifies amygdala responses during affective processing, suggesting an important role of the amygdala for mediating the interactions between breathlessness and affective states.

Mechanisms, measurement and management of exertional dyspnoea in asthma: Number 5 in the Series "Exertional dyspnoea" Edited by Pierantonio Laveneziana and Piergiuseppe Agostoni

Asthma is a heterogeneous condition, with dyspnoea during exercise affecting individuals to a variable degree. This narrative review explores the mechanisms and measurement of exertional dyspnoea in asthma and summarises the available evidence for the efficacy of various interventions on exertional dyspnoea. Studies on the mechanisms of dyspnoea in asthma have largely utilised direct bronchoprovocation challenges, rather than exercise, which may invoke different physiological mechanisms. Thus, the description of dyspnoea during methacholine challenge can differ from what is experienced during daily activities, including exercise. Dyspnoea perception during exercise is influenced by many interacting variables, such as asthma severity and phenotype, bronchoconstriction, dynamic hyperinflation, respiratory drive and psychological factors. In addition to the intensity of dyspnoea, the qualitative description of dyspnoea may give important clues as to the underlying mechanism and may be an important endpoint for future interventional studies. There is currently little evidence demonstrating whether pharmacological or non-pharmacological interventions specifically improve exertional dyspnoea, which is an important area for future research.

Arginine Vasopressin Alters Both Spontaneous and Phase-Locked Synaptic Inputs to Airway Vagal Preganglionic Neuron via Activation of V1a Receptor: Insights into Stress-Related Airway Vagal Excitation

The airway vagal preganglionic neurons (AVPNs) in the external formation of the nucleus ambiguus (eNA) play a major role in the vagal control of tracheobronchial smooth muscle tone and maintenance of airway resistance. The eNA receives vasopressinergic projection from the hypothalamic paraventricular nucleus (PVN), the key node for the genesis of psychological stress. Since airway vagal excitation is reportedly to be associated with the psychological stress-induced/exacerbated airway hyperresponsiveness in asthmatics, arginine vasopressin (AVP) might be involved in stress-related airway vagal excitation. However, this possibility has not been validated. This study aimed to test whether and how AVP regulates AVPNs. In rhythmically active medullary slices of newborn rats, retrogradely labeled AVPNs were identified as inspiratory-activated and inspiratory-inhibited AVPNs (IA- and II-AVPNs) using patch-clamp techniques according to their inspiratory-related firing behavior and synaptic activities. The results show that under current clamp, AVP depolarized both IA- and II-AVPNs, and significantly increased their spontaneous firing rate. Under voltage clamp, AVP elicited a slow inward current, and significantly increased the frequency of spontaneous excitatory postsynaptic currents (sEPSCs) in both types of AVPNs. In addition, AVP significantly enhanced the phase-locked excitatory inspiratory inward current in inspiratory-activated airway vagal preganglionic neurons (IA-AVPNs), but significantly suppressed the phase-locked inhibitory inspiratory outward current in II-AVPNs. In both types AVPNs, AVP significantly increased the frequency and amplitude of pharmacologically isolated spontaneous GABAergic and glycinergic inhibitory postsynaptic currents (IPSCs). All of the AVP-induced effects were prevented by SR49059, an antagonist of V_1a receptors, but unaffected by SSR149415, an antagonist of V_1b receptors. AVP did not cause significant changes in the miniature excitatory postsynaptic currents (mEPSCs), miniature inhibitory postsynaptic currents (mIPSCs) and membrane input resistance of either type of AVPNs. These results demonstrate that AVP, via activation of V_1a receptors, enhanced the spontaneous excitatory and inhibitory inputs similarly in the two types of AVPNs, but differentially altered their phase-locked inspiratory excitatory and inhibitory inputs. The overall effects of AVP are excitatory in both types AVPNs. These results suggest that increased central AVP release may be involved in the stress-induced augmentation of airway vagal activity, and, consequently, the induction or exacerbation of some airway diseases.

Interoceptive dimensions across cardiac and respiratory axes

Interoception refers to the sensing of signals concerning the internal state of the body. Individual differences in interoceptive sensitivity are proposed to account for differences in affective processing, including the expression of anxiety. The majority of investigations of interoceptive accuracy focus on cardiac signals, typically using heartbeat detection tests and self-report measures. Consequently, little is known about how different organ-specific axes of interoception relate to each other or to symptoms of anxiety. Here, we compare interoception for cardiac and respiratory signals. We demonstrate a dissociation between cardiac and respiratory measures of interoceptive accuracy (i.e. task performance), yet a positive relationship between cardiac and respiratory measures of interoceptive awareness (i.e. metacognitive insight into own interoceptive ability). Neither interoceptive accuracy nor metacognitive awareness for cardiac and respiratory measures was related to touch acuity, an exteroceptive sense. Specific measures of interoception were found to be predictive of anxiety symptoms. Poor respiratory accuracy was associated with heightened anxiety score, while good metacognitive awareness for cardiac interoception was associated with reduced anxiety. These findings highlight that detection accuracies across different sensory modalities are dissociable and future work can better delineate their relationship to affective and cognitive constructs.This article is part of the themed issue 'Interoception beyond homeostasis: affect, cognition and mental health'.

On the Origin of Interoception

Over the course of a century, the meaning of interoception has changed from the restrictive to the inclusive. In its inclusive sense, it bears relevance to every individual via its link to emotion, decision making, time-perception, health, pain, and various other areas of life. While the label for the perception of the body state changes over time, the need for an overarching concept remains. Many aspects can make any particular interoceptive sensation unique and distinct from any other interoceptive sensation. This can range from the sense of agency, to the physical cause of a sensation, the ontogenetic origin, the efferent innervation, and afferent pathways of the tissue involved amongst others. In its overarching meaning, interoception primarily is a product of the central nervous system, a construct based on an integration of various sources, not per se including afferent information. This paper proposes a definition of interoception as based on subjective experience, and pleas for the use of specific vocabulary in addressing the many aspects that contribute to it.

Could FEV₁ decline have a role in daily clinical practice for asthma monitoring?

OBJECTIVE

The aim of this review was to understand whether FEV1 decline measured during the follow-up of asthmatic subjects (FEV1 variation between two different measurements at a distance of at least 5 years) may have a role in their management.

METHODS

Articles, commentaries and reviews relating to the topic were searched in PubMed.

RESULTS

Patients with an accelerated FEV1 decline (>30 ml/year) may be either steroid-resistant/difficult-to-treat asthmatics or not adequately treated because they are either under-perceivers or poorly adherent to their therapy. Sometimes they may be unable to use devices correctly. Untreated rhinitis and incorrect lifestyle (obesity status, a high-fat diet and lack of exercise) must be considered when facing a pulmonary function decline. Identifying asthmatics with an accelerated FEV1 decline, even with well controlled symptoms, may allow us to make possible treatment adjustments or to remove potentially harmful environmental exposure and suggest a correct lifestyle. Depending on FEV1 decline severity, we may detect different asthma phenotypes. One type is characterized by no/low lung function reduction. Among moderate/severe 'declining' subjects, there may be a group that might be responsive to treatment and a second one with a quicker loss in lung function that may be unresponsive to therapy.

CONCLUSION

FEV1 decline calculation should be assessed early in clinical practice over the course of time in order to make all possible variations in treatment, environmental exposure and lifestyle more efficacious overall for declining subjects responsive to anti-inflammatory therapy. Further studies are necessary to validate this approach to asthma.