Dyspnea

Dyspnea induced by inspiratory loading limits dual-tasking in healthy young adults

OBJECTIVES

Dyspnea is a common and multidimensional experience of healthy adults and those with respiratory disorders. Due to its neural processing, it may limit or interfere with cognition, which may be examined with a dual-task paradigm. The aim of this study was to compare single-task performance of Stroop Colour and Word Test (SCWT) or inspiratory threshold loading (ITL) to their combined dual-task performance. Secondly, whether mood was related to dyspnea or cognitive performance was also evaluated.

MATERIALS & METHODS

A virtual pre-post design examined single (SCWT and ITL) and dual-task (SCWT+ITL) performance. For ITL, a Threshold Trainer™ was used to elicit a "somewhat severe" rating of dyspnea. The SCWT required participants to indicate whether a colour-word was congruent or incongruent with its semantic meaning. The Depression, Anxiety and Stress Scale-21 (DASS-21) was completed to assess mood. Breathing frequency, Borg dyspnea rating, and breathing endurance time were ascertained.

RESULTS

Thirty young healthy adults (15F, 15M; median age = 24, IQR [23-26] years) completed the study. SCWT+ITL had lower SCWT accuracy compared to SCWT alone (98.6%, [97.1-100.0] vs 99.5%, [98.6-100.0]; p = 0.009). Endurance time was not different between ITL and SCWT+ITL (14.5 minutes, [6.9-15.0]) vs 13.7 minutes, [6.1-15.0]; p = 0.59). DASS-21 scores positively correlated with dyspnea scores during ITL (rho = 0.583, p<0.001) and SCWT+ITL (rho = 0.592, p<0.001).

CONCLUSIONS

ITL significantly reduced dual-task performance in healthy young adults. Lower mood was associated with greater perceived dyspnea during single and dual-task ITL. Considering the prevalence of dyspnea in respiratory disorders, the findings of this dual task paradigm warrant further exploration to inform dyspnea management during daily activities.

Dyspnea: perfus?on ?ndex and tr?age status

PURPOSE

To determine the relationship between perfusion index and the emergency triage classification in patients admitted to the emergency department with dyspnea.

METHODS

Adult patients who presented with dyspnea and whose perfusion index values ​​were measured with Masimo Radical-7 device at the time of admission, at the first hour and the second hour of admission were included in the study. The PI and oxygen saturation measured by finger probes were compared and the superiority of their effects on the emergency triage classification was compared.

RESULTS

For the 0.9 cut- off value of the arrival PI level according to the triage status; sensitivity 79.25%; specificity 78.12%; positive predictive value is 66.7 and negative predictive value is 87.2. A statistically significant correlation was found between the triage status and the 0.9 cut- off value of the admission PI level. We can say that the ODDS rate of red triage is 13.63 times (95% CI: 5.99-31.01) times higher in cases with a PI level of 0.9 and below. In the ROC analysis, the cut-off value of 1.1 and above the admission PI level was determined as the most appropriate point for discharge.

CONCLUSION

The perfusion index can help to determine the triage classification in emergency departments for dyspnea.

Respiration Rate Extraction of Moving Subject Using Velocity Change in FMCW Radar

We propose a novel approach to determine the respiration rate of a moving subject, in terms of the velocity change, by using a frequency-modulated continuous-wave radar. In conventional methods, the respiration rate is determined by considering the variation in the distance between the targets and radar; however, these methods are vulnerable to the subject’s movements. The proposed approach estimates the respiration rate by considering the velocity, instead of the distance. An experiment was conducted to measure respiration in several subjects performing various movements. The experimental results demonstrate that the proposed method is more robust to the subject’s movements compared to conventional research methods, and can more accurately estimate the respiration rate.

Cardiopulmonary Exercise Testing with Echocardiography to Identify Mechanisms of Unexplained Dyspnea

Little data is available about the pathophysiological mechanisms of unexplained dyspnea and their clinical meaning. Consecutive patients with unexplained dyspnea underwent prospective standardized cardiopulmonary exercise testing with echocardiography (CPETecho). Patients were grouped as having normal exercise capacity (peak VO₂ > 80% with respiratory exchange [RER] > 1.05), reduced exercise capacity (peak VO₂ ≤ 80% with RER > 1.05), or a submaximal exercise test (RER ≤ 1.05). From 307 patients, 144 (47%) had normal and 116 (38%) reduced exercise capacity, and 47 (15%) had a submaximal exercise test. Patients with reduced versus normal exercise capacity had significantly more mechanisms for unexplained dyspnea (2.3±1.0 vs 1.5±1.0, respectively; p<0.001). Exercise PH (42%), low heart rate reserve (51%), low stroke volume reserve (38%), low diastolic reserve (18%), and peripheral muscle limitation (17%) were most common. Patients with more mechanisms for dyspnea displayed poorer peak VO₂ and had an increased risk for cardiovascular hospitalization (p=0.002). Patients with unexplained dyspnea display multiple coexisting mechanisms for exercise intolerance, which relate to the severity of exercise limitation and risk of subsequent cardiovascular hospitalizations.

Iron Deficiency Is Associated With Impaired Biventricular Reserve and Reduced Exercise Capacity in Patients With Unexplained Dyspnea

BACKGROUND

Iron deficiency (ID) is frequent and associated with diminished exercise capacity in heart failure (HF), but its contribution to unexplained dyspnea without a HF diagnosis at rest remains unclear.

METHODS AND RESULTS

Consecutive patients with unexplained dyspnea and normal echocardiography and pulmonary function tests at rest underwent prospective standardized cardiopulmonary exercise testing with echocardiography in a tertiary care dyspnea clinic. ID was defined as ferritin of <300 µg/L and a transferrin saturation of <20% and its impact on peak oxygen uptake (peakVO₂), biventricular response to exercise, and peripheral oxygen extraction was assessed. Of 272 patients who underwent cardiopulmonary exercise testing with echocardiography, 63 (23%) had ID. For a similar respiratory exchange ratio, patients with ID had lower peakVO₂ (14.6 ± 7.6 mL/kg/minvs 17.8 ± 8.8 mL/kg/min; P = .009) and maximal workload (89 ± 50 watt vs 108 ± 56 watt P = .047), even after adjustment for the presence of anemia. At rest, patients with ID had a similar left ventricular and right ventricular (RV) contractile function. During exercise, patients with ID had lower cardiac output reserve (P < .05) and depressed RV function by tricuspid s' (P = .004), tricuspid annular plane systolic excursion (P = .034), and RV end-systolic pressure-area ratio (P = .038), with more RV-pulmonary artery uncoupling measured by tricuspid annular plane systolic excursion/systolic pulmonary arterial pressure ratio (P = .023). RV end-systolic pressure-area ratio change from rest to peak exercise, as a load-insensitive metric of RV contractility, was lower in patients with ID (2.09 ± 0.72 mm Hg/cm² vs 2.58 ± 1.14 mm Hg/cm²; P < .001). ID was associated with impaired peripheral oxygen extraction (peakVO₂/peak cardiac output; P = .036). Cardiopulmonary exercise testing with echocardiography resulted in a diagnosis of HF with preserved ejection fraction in 71 patients (26%) based on an exercise E/e' ratio of >14, with equal distribution in patients with (28.6%) or without ID (25.4%, P = .611). None of these findings were influenced in a sensitivity analysis adjusted for a final diagnosis of HFpEF as etiology for the unexplained dyspnea.

CONCLUSIONS

In patients with unexplained dyspnea without clear HF at rest, ID is common and associated with decreased exercise capacity, diminished biventricular contractile reserve, and decreased peripheral oxygen extraction.

A comprehensive analysis of factors related to lung function in older adults: Cross-sectional findings from the Canadian Longitudinal Study on Aging

Maintenance of lung function is an often underappreciated, yet critical component of healthy aging. Given the unprecedented shift in the average age of Canadians over the next half century, it will be important to investigate the determinants of lung function in the elderly. In the following study, we estimated the association between lung function and a broad array of factors related to sociodemographics, lifestyle, chronic medical conditions and psychosocial factors in older adults aged 45-86 years old using cross-sectional data from the Canadian Longitudinal Study of Aging (n = 21,338). In addition to examining the entire cohort, we also performed stratified analyses within men/women, adults aged 45-64/65+, and healthy/comorbid. In multivariable regression, our explanatory factors (excluding age, sex, height and ethnicity) were able to explain 17% and 11% of the total variance in FEV₁ and FEV₁/FVC, respectively. Notable and significant contributions were observed for respiratory disease, smoking, obesity, income, and physical activity, while psychosocial factors mainly exhibited non-significant associations. Generally, these associations were stronger for males than females, and adults 65 and older as compared to those aged 45-64. Our findings indicate that there are pervasive and generally under-recognized sociodemographic and lifestyle factors that exhibit significant associations with FEV₁ and FEV₁/FVC in older adults. While implication of causality in these relationships is not possible due to the cross-sectional nature of the study, future work aiming to investigate determinants of lung health in older adults may choose to target these factors, given that many are modifiable.

Invasive cardiopulmonary exercise testing in the evaluation of unexplained dyspnea: Insights from a multidisciplinary dyspnea center

Background Unexplained dyspnea is a common diagnosis that often results in repeated diagnostic testing and even delayed treatments while a determination of the cause is being investigated. Through a retrospective study, we evaluated the diagnostic efficacy of a multidisciplinary dyspnea evaluation center (MDEC) using invasive cardiopulmonary exercise test to diagnose potential causes of unexplained dyspnea. Methods We reviewed the medical records of all patients referred with unexplained dyspnea to the MDEC between March 2011 and October 2014. We assessed the diagnostic efficacy before and after presentation to the MDEC. Results During the study period a total of 864 patients were referred to the MDEC and, of those, 530 patients underwent further investigation with invasive cardiopulmonary exercise test and constituted the study sample. The median age was 57 (44-68) years, 67.2% were women, and median body mass index was 26.22 (22.78-31.01). A diagnosis was made in 530 patients including: exercise pulmonary arterial hypertension of 88 (16.6%), heart failure with preserved ejection fraction of 94 (17.7%), dysautonomia 112 (21.1%), oxidative myopathy of 130 (24.5%), primary hyperventilation of 43 (8.1%), and other 58 (10.9%). The time from initial presentation to referral was significantly longer than time to diagnosis after referral for non-standardized conventional methods versus diagnosis through MDEC using invasive cardiopulmonary exercise test (511 days (292-1095 days) vs. 27 days (13-53 days), p < 0.0001). In a subgroup analysis, we reviewed that patients referred from cardiovascular clinics were more likely to have a greater number of diagnostic tests performed and, conversely, patients referred from pulmonary clinics were more likely to have a greater number of treatments prescribed before referral to MDEC. Conclusions As a result of this retrospective study, we have evaluated that a multidisciplinary approach that includes invasive cardiopulmonary exercise test dramatically reduces the time to diagnosis compared with traditional treatment and testing methods.

A breath sampling system assessing the influence of respiratory rate on exhaled breath composition

This work presents a computerized system to monitor mouth pressure, tidal volume, exhaled airflow, respiration rate and end-tidal partial pressure of CO2 during breath collection. The system was used to investigate the effect of different respiratory rates on the volatile organic compounds (VOCs) concentrations in exhaled breath. For this purpose, VOCs with well-defined biochemical pathways and different chemical and physical properties were selected as biomarkers related to metabolism (acetone and isopropyl alcohol), cholesterol synthesis (isoprene) and intestinal microflora activity (ethanol). Mixed breath was collected from a nominally healthy volunteer in resting conditions by filling a Nalophan bag. The subject followed a regimented breathing pattern at different respiratory rates (10, 30 and 50 breaths per minute). Results highlight that ventilation pattern strongly influences the concentration of the selected compounds. The proposed system allows exhaled breath to be collected also in patients showing dyspnea such as in case of chronic heart failure, asthma and pulmonary diseases.

Dyspnea related to reversibly-binding P2Y12 inhibitors: A review of the pathophysiology, clinical presentation and diagnostics

Dyspnea is a common symptom physiologically associated with strenuous exercise and pathologically reflecting well-known diseases and conditions that are predominantly pulmonary, cardiovascular, and weight-related in origin. Dyspnea improves with appropriate measures that enhance physical performance and treatment of the underlying diseases. Dyspnea is less commonly triggered by other causes such as the environment (e.g., ozone), drugs, and others, some of which do not seem to affect bronchopulmonary function as evidenced by normal results of comprehensive pulmonary function testing. In cardiovascular medicine, dyspnea has recently attracted attention because it has been reported that this symptom occurs more frequently with the administration of the new oral reversibly-binding platelet P2Y12 receptor inhibitors ticagrelor [1-6], cangrelor [7-10], and elinogrel [11]. This paper succinctly addresses the current understanding of the pathophysiology, clinical presentation, and diagnostics of dyspnea, associated either with bronchopulmonary function impairment, as triggered mainly by pulmonary and cardiovascular diseases, or without bronchopulmonary function impairment, as induced by endogenous or external compounds such as drugs in order to provide a context for understanding, recognizing and managing P2Y12 inhibitor-induced dyspnea.

The patient with dyspnea. Rational diagnostic evaluation

Dyspnea is the uncomfortable awareness of difficult breathing. It is a common symptom in primary and nonprimary care settings. Although multiple disorders and diseases may cause breathlessness, the majority of the conditions are of cardiac or pulmonary origin. The challenge is to establish the diagnosis timely and with minimized investigations. Frequently, information about onset, progression, and circumstances of occurrence considerably narrow the underlying etiology. In most cases, a carefully taken history and a comprehensive physical examination lead to the correct diagnosis. Nevertheless, one should be aware of concomitant conditions and not be satisfied with a diagnosis if comorbidity may still be a candidate in causing dyspnea. Otherwise, it has been observed that chronic obstructive pulmonary disease was over-diagnosed in patients with systolic heart failure and dyspnea. A prudential use of investigating modalities for confirmation and exclusion of a questionable diagnosis is the key for allocating the correct therapy and achieving fast symptom relief in patients with dyspnea.

Revisiting signs, strengths and weaknesses of Standard Chest Radiography in patients of Acute Dyspnea in the Emergency Department

Dyspnoea, defined as an uncomfortable awareness of breathing, together with thoracic pain are two of the most frequent symptoms of presentation of thoracic diseases in the Emergency Department (ED). Causes of dyspnoea are various and involve not only cardiovascular and respiratory systems. In the emergency setting, thoracic imaging by standard chest X-ray (CXR) plays a crucial role in the diagnostic process, because it is of fast execution and relatively not expensive. Although radiologists are responsible for the final reading of chest radiographs, very often the clinicians, and in particular the emergency physicians, are alone in the emergency room facing this task. In literature many studies have demonstrated how important and essential is an accurate direct interpretation by the clinician without the need of an immediate reading by the radiologist. Moreover, the sensitivity of CXR is much impaired when the study is performed at bedside by portable machines, particularly in the diagnosis of some important causes of acute dyspnoea, such as pulmonary embolism, pneumothorax, and pulmonary edema. In these cases, a high inter-observer variability of bedside CXR reading limits the diagnostic usefulness of the methodology and complicates the differential diagnosis. The aim of this review is to analyze the radiologic signs and the correct use of CXR in the most important conditions that cause cardiac and pulmonary dyspnoea, as acute exacerbation of chronic obstructive pulmonary disease, acute pulmonary oedema, acute pulmonary trombo-embolism, pneumothorax and pleural effusion, and to focus indications and limitations of this diagnostic tool.

Dyspnea as the reason for encounter in general practice

Background

Dyspnea is a common reason for consulting a physician. Data from the primary care setting on the epidemiology, management, and underlying causes of dyspnea have seldomly been published. The present study is aimed to explore the consultation prevalence of dyspnea, frequency of diagnostic and therapeutic procedures, accompanying symptoms and results of encounter or diagnoses of patients with dyspnea in a day-to-day primary care setting.

Methods

Cross-sectional data were collected from randomly selected patients during the SESAM 2 study (October 1, 1999 to September 30, 2000). Unpublished but publicly available data from the Dutch Transition Project were also analysed.

Results

One (n = 93; SESAM 2) and 3.9% (n = 7,855; Transition Project) of the patients consulted the practioner for dyspnea. The male to female ratio was almost 1 : 1. Half of the patients sought medical advice for not previously known dyspnea (Transition Project). Dyspnea occurs more frequently among small children (0 to 4 years) and elderly adults (> 64 years of age). Nearly all patients received a physical examination. Many causes were examined with the help of electrocardiograms but spirometry and laboratory tests were also used. Drug prescription was the most frequent (79.6%) therapeutic procedure. Acute bronchitis was the most common diagnosis. Dyspnea was significantly associated to cough, dysphagia, abnormal sputum, airway pain, sweating, and thoracic pain. There was also a significant association to chronic obstructive pulmonary disease.

Conclusions

Dyspnea is a common reason for seeking medical advice. Emergency cases (e.g. myocardial infarction) are rarely present in the general practitioner’s consultation. The majority of underlying causes are respiratory tract infections and exacerbated, previously known chronic diseases.

Keywords

Dyspnea; General practice; Primary care; Reason for encounter

Excess fluid volume: clinical validation in patients with decompensated heart failure

This cross-sectional study aimed to clinically validate the defining characteristics of the Nursing Diagnosis Excess Fluid Volume in patients with decompensated heart failure. The validation model used follows the model of Fehring. The subjects were 32 patients at a university hospital in Rio Grande do Sul. The average age was 60.5 ± 14.3 years old. The defining characteristics with higher reliability index (R): R ≥ 0.80 were: dyspnea, orthopnea, edema, positive hepatojugular reflex, paroxysmal nocturnal dyspnea, pulmonary congestion and elevated central venous pressure, and minor or secondary, R> 0.50 to 0.79: weight gain, hepatomegaly, jugular vein distention, crackles, oliguria, decreased hematocrit and hemoglobin. This study indicates that the defining characteristics with R> 0.50 and 1 were validated for the diagnosis Excess Fluid Volume.

Evaluation of the acutely dyspneic elderly patient

Dyspnea is among the most frequent complaints in the elderly. The prevalence of comorbid medical conditions and the physiologic changes of aging present significant challenges in determining the cause. The initial approach to the elderly dyspneic patient mandates consideration of a broad range of diagnoses. Failure to diagnose life-threatening medical conditions presenting with dyspnea such as pulmonary embolus, acute coronary syndromes, congestive heart failure, asthma, obstructive pulmonary disease, pneumothorax, and pneumonia can lead significant morbidity and mortality. This article focuses on the rapid assessment and approach to the acutely dyspneic elderly patient.

Personality profiles and pulmonary function of children with sighing dyspnoea

AIM

This study compared the personality profiles of children with sighing dyspnoea with healthy children and tested the hypothesis of heightened anxiety scores in sighing dyspnoeic subjects using the Childhood Behavior Check List for Ages 4 to 18 (CBCL/4-18). The pulmonary function tests of these two groups of children were also compared.

METHODS

This prospective study enrolled paediatric patients with sighing dyspnoea presented to a paediatric pulmonary clinic but free from apparent cardiopulmonary diseases, and age-matched healthy children were recruited for comparison. The psychological profiles of the patients were collected by the CBCL/4-18, which was completed by the parents. Spirometry was performed on sighing children as well as volunteer healthy children, before and after bronchodilator.

RESULTS

Twenty patients complained of sighing dyspnoea and 31 healthy children were included in the study. Both groups of children scored consistently within the normal ranges of all subscales including anxiety, somatic complaints or internalising behaviour on CBCL/4-18. The t-scores were not significant different between children with sighing dyspnoea and age-matched controls. Baseline forced vital capacity in the sighing patients appeared to be lower than the healthy children, but was not statistically significant.

CONCLUSIONS

The CBCL/4-18 scores of children with sighing dyspnoea were not significant different from age-matched healthy children and a heightened anxiety score was not confirmed in this study. Office spirometric values in patients with sighing dyspnoea were normal.

Molecular characterization of Arabidopsis PHO80-like proteins, a novel class of CDKA;1-interacting cyclins

Cyclins are regulatory proteins that interact with cyclin-dependent kinases (CDKs) to control progression through the cell cycle. In Arabidopsis thaliana, 34 cyclin genes have been described, grouped into five different types (A, B, D, H, and T). A novel class of seven cyclins was isolated and characterized in Arabidopsis, designated P-type cyclins (CYCPs). They all share a conserved central region of 100 amino acids ("cyclin box") displaying homology to the corresponding region of the PHO80 cyclin from Saccharomyces cerevisiae and the related G1 cyclins from Trypanosoma cruzi and T. brucei. The CYCP4;2 gene was able to partially re-establish the phosphate-dependent expression of the PHO5 gene in a pho80 mutant strain of yeast. The CYCPs interact preferentially with CDKA;1 in vivo and in vitro as shown by yeast two-hybrid analysis and co-immunoprecipitation experiments. P-type cyclins were mostly expressed in proliferating cells, albeit also in differentiating and mature tissues. The possible role of CYCPs in linking cell division, cell differentiation, and the nutritional status of the cell is discussed.