Dyspnea, respiratory function and sputum profile in asthmatic patients during exacerbations

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.

Measuring Pain. Visual Analog Scale Versus Numeric Pain Scale: What is the Difference?

Outcome measures are helpful in demonstrating patient response to care and therefore an important part of providing best care for our patients. Using paper scoring systems is one way that doctors of chiropractic can document patient progress. This update provides a brief review of the characteristics and applications of the visual analog scale (VAS) and numeric pain scale (NPS).

Dyspnea perception in asthma: role of airways inflammation, age and emotional status

OBJECTIVES

Dyspnea perception in asthmatics differs between subjects. Poor perception is usually associated with increased risk of asthma attack/exacerbation. The advanced stage of the disease and the presence of eosinophilic airways inflammation have been recently recognized as being responsible for poor dyspnea perception. However, few studies are available on this topic.

DESIGN

The aim of this study was to analyse the influence of inflammatory pattern, age and affective status on dyspnea perception in asthmatic subjects.

SUBJECTS AND INTERVENTIONS

Seventy-one consecutive asthmatic patients were recruited and underwent induced sputum, exhaled NO measurement and breath condensate collection. Perception of dyspnea was evaluated as a BORG-VAS/FEV(1) slope before and after the broncho-reversibility test and correlated with the stage of asthma, inflammatory markers, age and depression scale.

RESULTS

Dyspnea perception decreases with the worsening of asthma, with the advance of age and of depression status. Furthermore, airways inflammation plays a key role in the decline of dyspnea perception as proved by the negative correlation observed between inflammatory cells in sputum, exhaled pH and NO and BORG-VAS/FEV(1) slope.

CONCLUSIONS

The results of our study suggested that airways inflammation, depression status, advance age and severity of asthma influence dyspnea perception and suggest a straight control to identify and better manage poor preceptor asthmatics.

Relation between inflammation and symptoms in asthma

Asthma symptoms are the main reason for healthcare utilization and are a fundamental parameter for the evaluation of asthma control. Currently, asthma is defined as a chronic inflammatory disease. A French expert group studied the association between inflammation and asthma symptoms by carrying out a critical review of the international literature. Uncontrolled asthmatics have an increased number of polynuclear eosinophils in the induced sputum and an increased production of exhaled NO. Control by anti-inflammatory treatment is accompanied by a reduction in bronchial eosinophilia and exhaled NO. Asthma symptoms are the result of complex mechanisms and many factors modify their perception. Experimental data suggest that there is a relationship between the perception of symptoms and eosinophilic inflammation and that inhaled corticoid therapy improves this perception. Although they are still not applicable in routine practice, follow-up strategies based on the evaluation of inflammation are thought to be more effective in reducing exacerbations than those usually recommended based on symptoms and sequential analysis of respiratory function. Inhaled corticosteroid therapy is the reference disease-modifying therapy for persistent asthma. Recent studies demonstrated that adjustment of anti-inflammatory treatment based on symptoms is an effective strategy to prevent exacerbations and reduce the total number of doses of inhaled corticosteroids.

[The relationship between inflammation and symptoms in asthma]

In asthma, symptoms are the main reason for recourse to healthcare and are a fundamental parameter for the evaluation of asthma control. Currently, asthma is defined as a chronic inflammatory disease. Uncontrolled asthmatics have an increased number of eosinophils in induced sputum and an increased production of exhaled NO. Control by anti-inflammatory treatment is accompanied by a reduction in bronchial eosinophilia and exhaled NO. Asthma symptoms are the result of complex mechanisms and many factors modify their perception. Experimental data suggests that there is a relationship between the perception of symptoms and eosinophilic inflammation, and that inhaled corticoid therapy improves this perception. Although they are still not applicable in routine practice, follow-up strategies based on the evaluation of inflammation are thought to be more effective in reducing exacerbations than those usually recommended based on retrospective evaluation of symptoms and sequential analysis of respiratory function. Inhaled corticosteroid therapy is the reference maintenance therapy for persistent asthma and adjustment of anti-inflammatory treatment based on symptoms is an effective strategy to prevent exacerbations and reduce the total dose of inhaled corticosteroids. A French expert group has undertaken a study of the association between inflammation and asthma symptoms by carrying out a critical review of the international literature.

[Exacerbation in asthma: definitions and immunopathology]

There is no unequivocal definition of exacerbation in asthma. These are defined as episodes of increased or aggravated respiratory symptoms or as use of oral corticosteroid therapy. Viral infection is the most frequent cause of exacerbations. Inflammation during exacerbations is heterogeneous. It may be associated with bronchial hypereosinophilia, which is used as a predictive marker for exacerbation, and with neutrophilia, which is more resistant to corticosteroids. During viral infection, an inappropriate Th1 antiviral inflammation develops, associated with the intrinsic Th2 activity that leads to an aberrant immune response. Exacerbations secondary to allergen exposure are classically described as due to a Th2-type inflammation; but Th1 response also seems to play a role. Exposure to air pollutants appears able not only to induce bronchial inflammation but also to potentiate the inflammatory reactions of patients with exacerbations.

Perception of airway obstruction and airway inflammation in asthma: a review

Dyspnea has a multifactorial nature and the exact mechanism that causes breathlessness in asthma is not fully understood. There is compelling evidence that factors other than merely mechanical ones take part in the pathophysiology of breathlessness. Some recent reports attribute airway inflammation, which may contribute to the unexplained variability in the perception of dyspnea associated with bronchoconstriction. Eosinophil airway inflammation has been proposed as a determinant of breathlessness via mechanisms affecting either the mechanical pathways that control breathlessness or the afferent nerves involved in perception of dyspnea. In this review, data on the interrelation between inflammation and dyspnea sensation and the impact of treatment on dyspnea sensation are discussed. We conclude that regardless of whether mechanical or chemical inflammatory factors are involved, much variability in dyspnea scores remains unexplained.

Perception of dyspnea during exacerbation and histamine-related bronchoconstriction in patients with asthma

BACKGROUND

Numerous studies have been performed concerning the perception of dyspnea during changes in airway caliber provoked in the laboratory setting, but studies of asthma exacerbation are scarce.

OBJECTIVE

To investigate whether the perception of dyspnea during histamine-induced bronchoconstriction might be used to identify patients with asthma who sense dyspnea poorly during exacerbation.

METHODS

The perception of dyspnea in 50 patients (45 female, 5 male) with asthma was evaluated at admission with exacerbation and during a stable period. Perceived intensity of dyspnea was estimated using a modified Borg scale. The perception of dyspnea in the stable period 4 to 6 weeks after exacerbation was measured with the histamine challenge test. Perception parameters were defined as the change in Borg score divided by the change in forced expiratory volume in 1 second (FEV1) as a percentage of the baseline FEV1 (deltaBorg/deltaFEV1) and as the Borg score at 20% decrease (PS20Histamine) or increase (PS20Exacerbation) in FEV1.

RESULTS

The perception of dyspnea during asthma exacerbation was unrelated to the perception of dyspnea during histamine-induced bronchoconstriction (for deltaBorg/deltaFEV1, beta = .08, P = .50; for PS20, beta = -.11, P = .40). The kappa value for the agreement of poor perceivers at exacerbation and during the stable period was -0.21 (P = .10). However, the intensity of dyspnea caused by histamine-induced bronchoconstriction was lower than that caused by asthma exacerbation (PS20: 1.6 +/- 1.1 vs 2.8 +/- 2.5, respectively, P = .004; deltaBorg/deltaFEV1: 0.08 +/- 0.05 vs 0.21 +/- 0.28, respectively, P = .001).

CONCLUSION

The perception of dyspnea during asthma exacerbation is not correlated with the perception of dyspnea during histamine-induced bronchoconstriction. Therefore, the perception of dyspnea during histamine-induced bronchoconstriction cannot be used to identify the asthmatic patients who perceive dyspnea poorly.

Severe asthma: an overview

Severe asthma represents less than 10% of all asthma, but these patients are responsible for a disproportionate share of the health care costs and morbidity associated with the disease. A significant challenge in the diagnosis and management of severe asthma is the ability to identify accurately the patients most at risk for adverse outcomes, such as medication side effects, emergency department visits, hospitalization, near-fatal events, or disability from persistent symptoms or chronic lung function abnormalities. To improve the treatment of these patients, we must improve our understanding of the mechanisms responsible for severe disease. To achieve this goal, it is imperative to develop a common definition of severe asthma to allow adequate characterization of the disease clinically and provide the opportunity to compare results from many studies. Several severe asthma phenotypes have been described in the literature on the basis of the age of patients, age of disease onset, corticosteroid resistance, chronic airflow obstruction, and evidence for eosinophilic airway inflammation on biopsy. These phenotypes have led to an emerging interest in the use of noninvasive methods to monitor airway inflammation in severe asthma. Treatment algorithms based on markers of airway inflammation may decrease measures of health care utilization in severe asthma.

Asthma severity and asthma control: symptoms, pulmonary function, and inflammatory markers

PURPOSE OF REVIEW

Asthma severity and asthma control are distinct yet related concepts. Asthma severity describes the underlying disease in the absence of therapy and is ideally defined without concurrent treatment confounding its assessment. Asthma control describes the clinical status of disease in the face of intervention. However, the individual parameters by which we define asthma severity and asthma control overlap significantly. A MEDLINE search between July 1, 2002, and June 30, 2003, was performed using keywords related to concepts of asthma severity of illness and asthma control. From these articles the author selected the articles most relevant for discussion.

RECENT FINDINGS

Asthma is a complex syndrome. Although correlations exist between the various parameters used in clinical assessment, no single parameter can accurately classify all individuals. Assessment of multiple parameters including physiologic measures, symptoms, and activity limitation are necessary to categorize asthma clinical status accurately. In addition, the role biomarkers play in the assessment of disease status is an area of increasing interest. Several validated multidimensional measures for assessing asthma control are now available. Each of these measures includes the parameters of symptoms, activity limitation, and rescue medication use, yet they vary on inclusion of other important components such as physiologic measures and biomarkers.

SUMMARY

Asthma is a complex syndrome. Currently available instruments demonstrate an improved understanding of the multidimensional approach required to assess asthma control accurately. However, debate continues on the optimal parameters to be included and the role biomarkers play in the clinical assessment of asthma.