Loredana Stendardi

Understanding dyspnoea by its language

Dyspnoea is a general term used to characterise a range of qualitatively distinct descriptors that vary in intensity. Based on the hypothesis that various qualities of respiratory discomfort result from different pathophysiological abnormalities, language could help to define one or more of the abnormalities responsible for breathing discomfort. The use of descriptors of dyspnoea may contribute to the understanding of the mechanisms of dyspnoea, and assist in identifying or predicting a specific diagnosis. Symptoms that can be reliably discriminated imply different pathophysiological mechanisms, whereas symptoms that cannot be reliably discriminated imply similar pathophysiological mechanisms. Since dyspnoea is a fundamental part of patients clinical history, physicians should become more fluent in the language of dyspnoea.

Mechanisms of dyspnoea and its language in patients with asthma

This study hypothesises that regardless of the global score of dyspnoea intensity, different descriptors may be selected by asthmatic patients during short cardiopulmonary exercise test (sCPET) and methacholine (Mch) inhalation. It also examines whether different qualitative dyspnoea sensations can help explain the underlying mechanisms of the symptom. Minute ventilation (V′E), tidal volume (VT) and inspiratory capacity (IC) were measured in 22 stable asthmatic patients, and the sensation of dyspnoea during Mch inhalation and sCPET was quantitatively (Borg scale) and qualitatively (descriptors) assessed. The work rate and oxygen uptake (V′O2) were also measured during sCPET. Airway obstruction and hyperinflation, as measured by IC reduction, were the best correlates for dyspnoea with Mch. During sCPET, changes in WR, V′O2, V′E and VT significantly correlated with Borg score, with V′E being the best predictor of dyspnoea; IC decreased in eight patients. Furthermore, chest tightness (68%) was the highest reported descriptor during Mch inhalation, whereas work/effort (72%) was the highest during sCPET. In conclusion, obstruction/hyperinflation and work rate are highly reliable predictors of Borg rating of dyspnoea during methacholine inhalation and short cardiopulmonary exercise testing, respectively. Regardless of the global score of intensity dyspnoea, different descriptors may be selected by patients during short cardiopulmonary exercise testing and methacholine inhalation. Various qualities of dyspnoea result from different pathophysiological abnormalities.

Early oral presentation of lues maligna in a patient with HIV infection. A case report

We present a case of a patient infected with the human immunodeficiency virus who developed syphilis manifested by atypical early oral and skin ulcerations. The profound immune defects associated with human immunodeficiency virus may lead to an altered clinical presentation and a more aggressive course in patients infected with Treponema pallidum. The unusual clinical manifestations observed in this case emphasize the importance of considering secondary syphilis in the differential diagnosis of any inflammatory mucosal and skin disorder in patients with the human immunodeficiency virus.

Chest wall kinematics, respiratory muscle action and dyspnoea during arm vs. leg exercise in humans

Aim:  We hypothesize that different patterns of chest wall (CW) kinematics and respiratory muscle coordination contribute to sensation of dyspnoea during unsupported arm exercise (UAE) and leg exercise (LE).

Do obstructive and restrictive lung diseases share common underlying mechanisms of breathlessness

This review tries to answer two main questions: (i) What are the neurophysiological underpinnings of the most commonly selected cluster descriptors which define the qualitative dimension of dyspnea in patients? (ii) How do mechanical constraints affect dyspnea? (iii) Do obstructive and restrictive lung diseases share some common underlying mechanisms? Qualitative dimensions of dyspnea, which allude to increased respiratory work/effort breathing, reflect a harmonious coupling between increased respiratory motor output and lung volume displacement in healthy subjects. Descriptors that allude to unsatisfied inspiration are the dominant qualitative descriptors in patients with a variety of respiratory diseases. It is possible that sensory feedback from a multitude of mechanoreceptors throughout the respiratory system (in the muscle, chest wall, airways and lung parenchyma) collectively convey information to the consciousness that volume/flow or chest wall displacement is inadequate for the prevailing respiratory drive. The data would lend support to the idea that: (i) an altered afferent proprioceptive peripheral feedback signals that ventilatory response is inadequate to the prevailing motor drive, reflecting neuromechanical uncoupling (NMU), (ii) mechanical constraints on volume expansion (dynamic restriction) play a pivotal role in dyspnea causation in patients with a variety of either obstructive or restrictive respiratory disorders, and (iii) all of the physiological adaptations that optimize neuromechanical coupling in obstructive and restrictive disorders are seriously disrupted so that an NMU underpins cluster descriptors of dyspnea which are similar in obstructed and in restricted patients.

Chest wall kinematics and Hoover's sign

BACKGROUND No attempt has been made to quantify the observed rib cage distortion (Hoovers sign) in terms of volume displacement. We hypothesized that Hoovers sign and hyperinflation are independent quantities. METHODS Twenty obstructed stable patients were divided into two groups according to whether or not they exhibited Hoovers sign during clinical examination while breathing quietly. We evaluated the volumes of chest wall and its compartments: the upper rib cage, the lower rib cage and the abdomen, using optoelectronic plethysmography. RESULTS The volumes of upper rib cage, lower rib cage and abdomen as a percentage of absolute volume of the chest wall were similar in patients with and without Hoovers sign. In contrast, the tidal volume of the chest wall, upper rib cage, lower rib cage, their ratio and abdomen quantified Hoovers sign, but did not correlate with level of hyperinflation. CONCLUSIONS Rib cage distortion and hyperinflation appear to define independently the functional condition of these patients.

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.

The respiratory muscles in eucapnic obesity: Their role in dyspnea

Regular exercise appears to be one of the best predictors of successful weight maintenance. Although physical activity and exercise are important components in the prevention and treatment of obesity, many obese adults without coexisting disorders are unable to exercise due to dyspnea on exertion. As a result they may not participate in regular physical activity. Therefore exertional dyspnea in obese adults is also an obstacle to the prevention and treatment of obesity and coexisting comorbidities. The available data suggest that increased respiratory muscle force generation, and the concomitant increase in respiratory neural drive associated with increased ventilation are an important source of sensation of respiratory effort in obese subjects. Whether activity-related breathlessness is due to either abnormal respiratory mechanical factors (flow limitation and/or chest elastic loading) or the increased metabolic demand of locomotion in obesity, or both of these together, the available data indicate that intensity of dyspnea at any given ventilation and oxygen uptake does not increase in obese subjects as compared with normal weight control subjects. Does this mean that respiratory mechanical factors are unlikely to be contributory? Nonetheless, the component of metabolic cost of breathing may not be accounted for in the measured mechanical work of breathing because of the number of included complex variables. That a decrease in efficiency of the respiratory muscles during exercise contributes to dyspnea in hyperinflating obese subjects should not be disregarded.

Chest wall kinematics and breathlessness during unsupported arm exercise in COPD patients

We hypothesised that chest wall displacement inappropriate to increased ventilation contributes to dyspnoea more than dynamic hyperinflation or dyssynchronous breathing during unsupported arm exercise (UAE) in COPD patients. We used optoelectronic plethysmography to evaluate operational volumes of chest wall compartments, the upper rib cage, lower rib cage and abdomen, at 80% of peak incremental exercise in 13 patients. The phase shift between the volumes of upper and lower rib cage (RC) was taken as an index of RC distortion. With UAE, no chest wall dynamic hyperinflation was found; sometimes the lower RC paradoxed inward while in other patients it was the upper RC. Phase shift did not correlate with dyspnoea (by Borg scale) at any time, and chest wall displacement was in proportion to increased ventilation. In conclusions neither chest wall dynamic hyperinflation nor dyssynchronous breathing per se were major contributors to dyspnoea. Unlike our prediction, chest wall expansion and ventilation were adequately coupled with each other.

Optoelectronic Plethysmography has Improved our Knowledge of Respiratory Physiology and Pathophysiology

It is well known that the methods actually used to track thoraco-abdominal volume displacement have several limitations. This review evaluates the clinical usefulness of measuring chest wall kinematics by optoelectronic plethysmography [OEP]. OEP provides direct measurements (both absolute and its variations) of the volume of the chest wall and its compartments, according to the model of Ward and Macklem, without requiring calibration or subject cooperation. The system is non invasive and does not require a mouthpiece or nose-clip which may modify the pattern of breathing, making the subject aware of his breathing. Also, the precise assessment of compartmental changes in chest wall volumes, combined with pressure measurements, provides a detailed description of the action and control of the different respiratory muscle groups and assessment of chest wall dynamics in a number of physiological and clinical experimental conditions.