Determining the cause of dyspnoea: linguistic and biological descriptors

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.

Pulse amplitude ratio under noninvasive ventilation as a new method in the diagnosis of left heart failure in patients with acute exacerbation of chronic obstructive pulmonary disease

BACKGROUND

Left heart failure (LHF) is commonly associated with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) but its role is often underestimated.

AIM OF STUDY

To evaluate the performance of a new diagnostic technique based on the measurement of the pulse amplitude ratio (PAR) using non-invasive ventilation (NIV) for the early identification LHF in patients admitted to the emergency department (ED) for AECOPD.

RESULTS

73 patients were included in this study: 32 in LHF group and 41 in non LHF- group. The two groups had comparable demographic and clinical characteristics at admission. The mean values of PAR_NIV was significantly higher among LHF patients (0.86 vs. 0.71; p < 0.01). The area under the receiver operating characteristic curve of PAR_NIV was 0.75. Using the best cut-off (0.6), the sensitivity of PAR_NIV was 93% with a specificity 21%, a positive predictive value of 48%, and a negative predictive value of 81%. Correlation between PAR_NIV and BNP was significant (r = 0.52; p = 0.002).

CONCLUSION

Measurement of PAR_NIV in patients presenting to the ED with AECOPD had a good diagnostic performance for the detection of LHF and could represent an interesting alternative for the currently available methods. Trial registration The study was registered in the Clinical Trial Registration System (clinicaltrials.gov) under the study number NCT05189119, https://register.

CLINICALTRIALS

gov/prs/app/action/SelectProtocol?sid=S000BOO4&selectaction=Edit&uid=U0000QAM&ts=2&cx=qrmluh .

The Importance of Respiratory Rate Monitoring: From Healthcare to Sport and Exercise

Respiratory rate is a fundamental vital sign that is sensitive to different pathological conditions (e.g., adverse cardiac events, pneumonia, and clinical deterioration) and stressors, including emotional stress, cognitive load, heat, cold, physical effort, and exercise-induced fatigue. The sensitivity of respiratory rate to these conditions is superior compared to that of most of the other vital signs, and the abundance of suitable technological solutions measuring respiratory rate has important implications for healthcare, occupational settings, and sport. However, respiratory rate is still too often not routinely monitored in these fields of use. This review presents a multidisciplinary approach to respiratory monitoring, with the aim to improve the development and efficacy of respiratory monitoring services. We have identified thirteen monitoring goals where the use of the respiratory rate is invaluable, and for each of them we have described suitable sensors and techniques to monitor respiratory rate in specific measurement scenarios. We have also provided a physiological rationale corroborating the importance of respiratory rate monitoring and an original multidisciplinary framework for the development of respiratory monitoring services. This review is expected to advance the field of respiratory monitoring and favor synergies between different disciplines to accomplish this goal.

Inspiring change: humanities and social science insights into the experience and management of breathlessness

PURPOSE OF REVIEW

Breathlessness can be debilitating for those with chronic conditions, requiring continual management. Yet, the meaning of breathlessness for those who live with it is poorly understood in respect of its subjective, cultural, and experiential significance. This article discusses a number of current issues in understanding the experience of breathlessness.

RECENT FINDINGS

Effective communication concerning the experience of breathlessness is crucial for diagnosis, to identify appropriate treatment, and to provide patients with the capacity to self-manage their condition. However, there is an evident disconnect between the way breathlessness is understood between clinical and lay perspectives, in terms of awareness of breathlessness, the way symptoms are expressed, and acknowledgement of how it affects the daily lives of patients.

SUMMARY

The review highlights the need for integrated multidisciplinary work on breathlessness, and suggests that effective understanding and management of breathlessness considers its wider subjective and social significance.

Ageism, negative attitudes, and competing co-morbidities--why older adults may not seek care for restricting back pain: a qualitative study

Background

Back pain, the most common type of pain reported by older adults, is often undertreated for reasons that are poorly understood, especially in minority populations. The objective of this study was to understand older adults’ beliefs and perspectives regarding care-seeking for restricting back pain (back pain that restricts activity).

Methods

We used data from a diverse sample of 93 older adults (median age 83) who reported restricting back pain during the past 3 months. A semi-structured discussion guide was used in 23 individual interviews and 16 focus groups to prompt participants to share experiences, beliefs, and attitudes about managing restricting back pain. Transcripts were analyzed in an iterative process to develop thematic categories.

Results

Three themes for why older adults may not seek care for restricting back pain were identified: (1) beliefs about the age-related inevitability of restricting back pain, (2) negative attitudes toward medication and/or surgery, and (3) perceived importance of restricting back pain relative to other comorbidities. No new themes emerged in the more diverse focus groups.

Conclusions

Illness perceptions (including pain-related beliefs), and interactions with providers may influence older adults’ willingness to seek care for restricting back pain. These results highlight opportunities to improve the care for older adults with restricting back pain.

Respiratory muscle endurance is limited by lower ventilatory efficiency in post-myocardial infarction patients

Background

Reduced respiratory muscle endurance (RME) contributes to increased dyspnea upon exertion in patients with cardiovascular disease.

Objective

The objective was to characterize ventilatory and metabolic responses during RME tests in post-myocardial infarction patients without respiratory muscle weakness.

Method

Twenty-nine subjects were allocated into three groups: recent myocardial infarction group (RG, n=9), less-recent myocardial infarction group (LRG, n=10), and control group (CG, n=10). They underwent two RME tests (incremental and constant pressure) with ventilatory and metabolic analyses. One-way ANOVA and repeated measures one-way ANOVA, both with Tukey post-hoc, were used between groups and within subjects, respectively.

Results

Patients from the RG and LRG presented lower metabolic equivalent and ventilatory efficiency than the CG on the second (50± 06, 50± 5 vs. 42± 4) and third part (50± 11, 51± 10 vs. 43± 3) of the constant pressure RME test and lower metabolic equivalent during the incremental pressure RME test. Additionally, at the peak of the incremental RME test, RG patients had lower oxygen uptake than the CG.

Conclusions

Post-myocardial infarction patients present lower ventilatory efficiency during respiratory muscle endurance tests, which appears to explain their inferior performance in these tests even in the presence of lower pressure overload and lower metabolic equivalent.

Screening for colorectal cancer: how can we maximize uptake?

SUMMARY Screening for colorectal cancer is being introduced in a number of countries, yet uptake remains low. The rationalistic model of screening participation explains low uptake in terms of deficient knowledge and high cost. There is evidence to support this view and remedial actions produce anticipated effects up to a point. However, differential uptake among specific groups suggests that the individual decision to participate in screening is idiosyncratic, and understanding decisions requires interpretation in terms of message framing, reference points, the use of simplifying heuristics and affective or emotional reaction. As these aspects of decisions originate from fundamental personal characteristics, they may be difficult to combat. When decision determinants, such as fear and herding, are manipulated, consequences for uptake can be contradictory.

Provider approaches to palliative dyspnea assessment: implications for informatics-based clinical tools

AIM

To understand provider practices around dyspnea assessment to inform the development of an electronic medical record (EMR)-based dyspnea assessment module in an inpatient palliative care consultation template.

DESIGN

Qualitative analysis of palliative care provider interviews.

RESULTS

Three themes emerged: (1) integration of patient self-report of breathlessness with a clinical observation of dyspnea; (2) identification of patients for dyspnea assessment based on perceived patient need; and (3) variability in preferences for and use of existing severity scales for dyspnea.

CONCLUSIONS

The assessment approaches described by providers underscore the challenge of developing an informatics tool that supports the natural clinical experience and facilitates standardized care. The complexity of the dyspnea assessment process and variation in provider practices necessitate a level of flexibility and choice to be built into a computer-based tool.

Bronchial hyperresponsiveness, word descriptors, and ethnicity: women with mild asthma

BACKGROUND

Few studies have examined the ethnic differences in symptom reporting and airway hyperresponsiveness (AHR) for women with mild asthma during a methacholine (McH) challenge.

OBJECTIVE

The purpose of this sub-analysis was to determine: (1) whether AHR to McH varied by the ethnicity of women with mild asthma and (2) whether ethnic word descriptors (EWDs) varied by the ethnicity during induced bronchoconstriction.

METHODS

Specific inclusion criteria included the following: FEV(1) (forced expiratory volume in 1 second) ≥ 70% predicted normal, PC(30) ≤ 8 mg/McH, β(2) inhaler only, and self-reported ethnicity of African American (AFAM), Mexican American-Hispanic-Latino (MexAMLat), Asian-Pacific Islander (Asian PI), or white. Serial pulmonary function testing (PFT) and Borg, visual analogue scale (VAS), and EWDs were collected.

RESULTS

A total of 44 women, mean age of 31.3 years old, with a mean baseline FEV(1) of 2.85 L comprised this sub-analysis. Ethnic-racial diversity included: 12 AFAMs, 5 MexAMLat, 13 Asian-PIs, and 14 whites. All had atopy ≥ 2 pinprick responses of 3 mm. At PC(30), Asian-PI women required a significantly (p < .05) smaller mean dose of McH 1.9 mg/mL. MexAMLat women required an McH dose of 1.6 mg/mL. At PC(30), McH dose was 2.9 mg/mL for AFAMs and 3.0 mg/mL for whites, respectively. Asian-PIs who used only upper airway EWDs at PC(30) vere itchy throat, itchy chin, and constricted throat (p < .001). AFAMs significant EWDs were itchy throat, itchy chin/face, and tight throat (p < .01). Lower airway EWD was used by both MexAMLat and whites. Significant EWD for Whites were tight chest (p < .01) and hard to inhale/lungs tight (p < .001).

CONCLUSION

Asian-PI women required a significantly smaller dose (p < .05) of McH to induce a PC(30). AFAM and whites required a comparable dose of Mch at PC(30). Asian-PI and AFAM women used only upper airway EWD. Asian-PI women may be at a greater risk for acute asthma episodes that are not recognized or treated due to their upper airway symptom reporting.

Effects of inspiratory muscle training in patients with heart failure

AIM

To investigate the effects of inspiratory muscle training (IMT) on functional capacity and balance, respiratory and peripheral muscle strength, pulmonary function, dyspnea, fatigue, depression, and quality of life in heart failure patients.

METHODS

A prospective, randomized controlled, double-blinded study. Thirty patients with heart failure (NYHA II-III, LVEF<40%) were included. Sixteen patients received IMT at 40% of maximal inspiratory pressure (MIP), and 14 patients received sham therapy (15% of MIP) for 6 weeks. Functional capacity and balance, respiratory muscle strength, quadriceps femoris muscle strength, pulmonary function, dyspnea, fatigue, quality of life, and depression were evaluated.

RESULTS

Functional capacity and balance, respiratory and peripheral muscle strength, dyspnea, depression were significantly improved in the treatment group compared with controls; quality of life and fatigue were similarly improved within groups (p < 0.05). Functional capacity (418.59 ± 123.32 to 478.56 ± 131.58 m, p < 0.001), respiratory (MIP = 62.00 ± 33.57 to 97.13 ± 32.63 cmH(2)O, p < 0.001) and quadriceps femoris muscle strength (240.91 ± 106.08 to 301.82 ± 111.86 N, p < 0.001), FEV(1)%, FVC% and PEF%, functional balance (52.73 ± 3.15 to 54.25 ± 2.34, p < 0.001), functional dyspnea (2.27 ± 0.88 to 1.07 ± 0.79, p < 0.001), depression (11.47 ± 7.50 to 3.20 ± 4.09, p < 0.001), quality of life, fatigue (42.73 ± 11.75 to 29.07 ± 13.96, p < 0.001) were significantly improved in the treatment group. Respiratory muscle strength (MIP = 78.64 ± 35.95 to 90.86 ± 30.23 cmH(2)O, p = 0.001), FVC%, depression (14.36 ± 9.04 to 9.50 ± 10.42, p = 0.011), quality of life and fatigue (42.86 ± 12.67 to 32.93 ± 15.87, p = 0.008) were significantly improved in the control group.

CONCLUSION

The IMT improves functional capacity and balance, respiratory and peripheral muscle strength; decreases depression and dyspnea perception in patients with heart failure. IMT should be included effectively in pulmonary rehabilitation programs.

Mechanisms of dyspnea

The mechanisms and pathways of the sensation of dyspnea are incompletely understood, but recent studies have provided some clarification. Studies of patients with cord transection or polio, induced spinal anesthesia, or induced respiratory muscle paralysis indicate that activation of the respiratory muscles is not essential for the perception of dyspnea. Similarly, reflex chemostimulation by CO₂ causes dyspnea, even in the presence of respiratory muscle paralysis or cord transection, indicating that reflex chemoreceptor stimulation per se is dyspnogenic. Sensory afferents in the vagus nerves have been considered to be closely associated with dyspnea, but the data were conflicting. However, recent studies have provided evidence of pulmonary vagal C-fiber involvement in the genesis of dyspnea, and recent animal data provide a basis to reconcile differences in responses to various C-fiber stimuli, based on the ganglionic origin of the C fibers. Brain imaging studies have provided information on central pathways subserving dyspnea: Dyspnea is associated with activation of the limbic system, especially the insular area. These findings permit a clearer understanding of the mechanisms of dyspnea: Afferent information from reflex stimulation of the peripheral sensors (chemoreceptors and/or vagal C fibers) is processed centrally in the limbic system and sensorimotor cortex and results in increased neural output to the respiratory muscles. A perturbation in the ventilatory response due to weakness, paralysis, or increased mechanical load generates afferent information from vagal receptors in the lungs (and possibly mechanoreceptors in the respiratory muscles) to the sensorimotor cortex and results in the sensation of dyspnea.

A review of dyspnea in acute heart failure syndromes

In acute heart failure syndrome (AHFS), dyspnea is one of the most common but least understood presenting symptoms for hospitalization. For this reason, dyspnea relief is increasingly becoming a focus in the development of therapies for the treatment of AHFS, and currently stands as an acceptable primary end point for regulatory approval by governmental agencies. This raises the question of how best to measure such a subjective symptom. In this review, we will describe the basis for dyspnea, provide a detailed description of the strengths and weaknesses of the current best tools used to measure it, and describe future directions for future development of dyspnea measurement in AHFS.

Physician vs patient assessment of dyspnea during acute decompensated heart failure

This study assessed agreement between physician and patient self-reported measures of dyspnea severity during acute decompensated heart failure (ADHF). Both the physician and patient measured the change in dyspnea severity over 1 hour using 2 methods: (1) the difference of two static dyspnea measures (STATIC) and (2) a single transitional measure (TRANS). Likert scales and visual analog scales (VASs) were used. Data on 112 patients were analyzed. The mean difference between physician and patient VAS scores was 1 mm (limits of agreement: -54 to 56 mm) using the STATIC data. For TRANS data, the mean difference was 5 mm (limits of agreement: -75 to 86 mm). For the Likert scales, the weighted kappa was 0.13 and 0.23 for STATIC and TRANS data, respectively. The wide limits of agreement restrict our ability to substitute physician assessment for patient self-assessment of dyspnea in patients with ADHF.

Ethnic differences in methacholine responsiveness and word descriptors in African Americans, Hispanic-Mexican Americans, Asian-Pacific Islanders, and Whites with mild asthma

OBJECTIVE

There is little asthma research that compares ethnic differences in airway responsiveness and word descriptors among African Americans, Hispanic-Mexican Americans, Asian-Pacific Islanders, and Whites. Thus, identifying ethnic differences in symptom descriptors and airway responsiveness may improve health outcomes by educating health professionals about treatment decisions that are culturally and ethnically sensitive.

METHODS

Specific Inclusion criteria-forced expiratory volume in one second (FEV(1)) >or= 70% predicted normal; provocative concentration causing a 30% fall in FEV(1) (PC(30)) <or= 8 mg/ml for methacholine (MCh), using only a beta(2)- inhaler, and self-reported ethnicity of African American, Hispanic-Mexican American, Asian-Pacific Islander, or White. Serial pulmonary function test (PFT) and Borg, Visual Analogue Scale (VAS), and Ethnic Word Descriptors (EWDs) were collected.

RESULTS

One hundred eighteen consented, 106 completed procedures, and 90 had a positive PC(30) and were enrolled. Asian-Pacific Islanders had significantly greater airway responsiveness (p <.02). Baseline FEV(1), MCh dose, and PC(30) correlated with race (p <.001); baseline FEV(1) and ethnicity predicted airway responsiveness (p <.001). EWDs differed significantly by ethnicity. Upper airway EWDs for Asian-Pacific Islanders: itchy throat (p < .04), itchy (p <.02), itchy back throat (p <.04), voice tight, tight throat (p <.001), and cough (p <.04). Upper airway EWDs for African Americans: add itchy throat (p <.002), itchy neck (p <.001), tight throat (p <.003), voice tight (p <.02), and cough (p <.04). Hispanic-Mexican Americans used both upper and lower airway EWDs; Whites used only lower airway EWDs.

CONCLUSION

This study provides new insights about ethnic differences in airway responsiveness and EWDs. Asian-Pacific Islanders required a significantly smaller dose of MCh to achieve a PC(30) compared to the other three ethnic groups. The upper airway EWDs used by African Americans, Asian-Pacific Islanders, and Hispanic-Mexican Americans indicate a shared language of symptoms. A new language of breathlessness that incorporates both cultural and ethnic differences is needed to address the present disparity in the management of asthma symptoms.

Uptake of colorectal cancer screening: system, provider and individual factors and strategies to improve participation

Colorectal cancer (CRC) accounts for 9% of all new cancer cases worldwide and affects over 1 million people each year. Screening can reduce the mortality associated with the disease, yet participation rates are suboptimal. Compliers with CRC screening are less deprived; they have higher education than noncompliers and tend to be male, white and married. Likely reasons for nonparticipation encompass several 'modifiable' factors that could be targeted in interventions aimed at increasing participation rates. Successful intervention strategies include organizational changes, such as increasing access to fecal occult blood test (FOBT) kits, providing reminders to healthcare providers or users about screening opportunities, and educational strategies to improve awareness and attitudes towards CRC screening. Multifactor interventions that target more than one level of the screening process are likely to have larger effects. The biggest challenge for future research will be to reduce inequalities related to socio-economic position and ethnicity in the uptake of screening.

Tiotropium and exercise training in COPD patients: effects on dyspnea and exercise tolerance

BACKGROUND

Exercise training improves exercise tolerance in chronic obstructive pulmonary disease (COPD). Tiotropium 18 microg once daily induces sustained bronchodilation throughout the day and reduces hyperinflation, one of the pathophysiological factors contributing to exertional dyspnea in COPD patients.

AIM

To determine whether tiotropium enhances the effects of exercise training in patients with COPD.

DESIGN

Multicenter, 25 week randomized, double-blind, placebo-controlled, parallel-group study.

SETTING

Twelve Italian Pulmonary Units practicing pulmonary rehabilitation.

PATIENTS AND INTERVENTION

Two hundred thirty four COPD patients (196 males; mean age: 67.4 +/- 7.6; forced expiratory volume at 1 second (FEV1): 41.4 +/- 13.0% predicted) were randomised to tiotropium 18 microg or placebo inhalation capsules taken once daily. Both groups underwent a 8 week pulmonary rehabilitation program (PR) consisting of 3 exercise training session per week.

MEASUREMENTS

Baseline, at the end of PR and after 12 weeks, patients completed pulmonary function testing, six minute walking test (6MWT), the Baseline and Transition Dyspnea Index (BDI and TDI), and the St. George's Respiratory Questionnaire (SGRQ).

RESULTS

Relative to placebo, tiotropium had larger trough and post-study drug FEV1 responses on all test days. At the end of and 12 weeks following PR, patients on tiotropium showed no statistically significant differences in 6MWT compared to patients on placebo. Compared to the period immediately prior to PR, the mean improvement in 6MWT was only 29.7 meters (7.1%) for the combined cohort. Mean TDI focal scores at the end of PR were 3.60 for tiotropium and 2.25 for placebo (p < 0.01). At 12 weeks after PR, TDI focal scores were 2.71 for tiotropium and 2.11 for placebo (p = 0.16). Reduction in all four SGRQ component scores, indicating an improvement in health-related quality of life, was observed for the tiotropium group over the duration of the study compared to placebo but the differences were not statistically significant. During the study period, there were fewer exacerbations and exacerbation days in the tiotropium group.

CONCLUSION

Although significant improvements were observed with perceived dyspnea, compared to placebo, the addition of tiotropium to pulmonary rehabilitation did not improve the 6MWT.

New Approaches in Pulmonary Rehabilitation

Patients who have mild to severe chronic obstructive pulmonary disease may obtain improvement in dyspnea, exercise capacity, and health-related quality of life as a result of exercise training. The type and intensity of training is of key importance in determining outcomes. High-intensity aerobic training leads to physiologic gains in aerobic fitness. Nevertheless, extreme breathlessness or peripheral muscle fatigue may prevent some patients from performing high-intensity exercise; therefore, new tools are needed to improve the effectiveness of pulmonary rehabilitation.

The relationship between dyspnea and blood pressure in chronic obstructive pulmonary disease

BACKGROUND AND RESEARCH OBJECTIVE

Although dyspnea is a frequently encountered clinical symptom, precise clinical evaluation of this sensation remains illusive. Dyspnea has been difficult to evaluate empirically, as severity of mechanical pulmonary impairment does not appear to correlate with subjectively reported levels of dyspnea. The purpose of this study was to describe changes in dyspnea and blood pressure with the use of an incentive spirometry and to examine the relationship of such changes in patients with chronic obstructive pulmonary disease.

SUBJECTS AND METHODS

A convenience sample of 60 adults diagnosed with chronic obstructive pulmonary disease was recruited from ambulatory outpatient clinics at a large Veterans hospital. A quantitative single-group, within-subjects repeated-measure design was used to investigate the relationship between the variables following incentive spirometry. Dyspnea levels were recorded with the visual analog scale and arterial blood pressures (beat-to-beat systolic, mean, and diastolic) were continuously recorded with tonometry.

RESULTS AND CONCLUSIONS

The first 4 periods following use of the incentive spirometer were found to have statistically significant increases from dyspnea baseline scores (F = 77.4, P < .001). The baseline of each of the arterial blood pressure measurements, systolic, mean, and diastolic, were found to have significant differences with all of the 6 postintervention time points (systolic F = 8.0, P < .001; mean F = 7.1, P < .001; diastolic F = 7.2, P < .001). The changes in dyspnea scores and blood pressure measurements were found to have significant inverse correlations at the immediate postintervention time point (r = -0.32 to -0.35, P < .01). Results provide evidence of an inverse relationship between dyspnea and blood pressure patterns and may indicate significant clinical associations to add to the body of knowledge about the symptom of dyspnea.