Multiple dimensions of cardiopulmonary dyspnea / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The current theory of dyspnea perception presumes a multidimensional conception of dyspnea. However, its validity in patients with cardiopulmonary dyspnea has not been investigated.</p><p><b>METHODS</b>A respiratory symptom checklist incorporating spontaneously reported descriptors of sensory experiences of breathing discomfort, affective aspects, and behavioral items was administered to 396 patients with asthma, chronic obstructive pulmonary disease (COPD), diffuse parenchymal lung disease, pulmonary vascular disease, chronic heart failure, and medically unexplained dyspnea. Symptom factors measuring different qualitative components of dyspnea were derived by a principal component analysis. The separation of patient groups was achieved by a variance analysis on symptom factors.</p><p><b>RESULTS</b>Seven factors appeared to measure three dimensions of dyspnea: sensory (difficulty breathing and phase of respiration, depth and frequency of breathing, urge to breathe, wheeze), affective (chest tightness, anxiety), and behavioral (refraining from physical activity) dimensions. Difficulty breathing and phase of respiration occurred more often in COPD, followed by asthma (R(2) = 0.12). Urge to breathe was unique for patients with medically unexplained dyspnea (R(2) = 0.12). Wheeze occurred most frequently in asthma, followed by COPD and heart failure (R(2) = 0.17). Chest tightness was specifically linked to medically unexplained dyspnea and asthma (R(2) = 0.04). Anxiety characterized medically unexplained dyspnea (R(2) = 0.08). Refraining from physical activity appeared more often in heart failure, pulmonary vascular disease, and COPD (R(2) = 0.15).</p><p><b>CONCLUSIONS</b>Three dimensions with seven qualitative components of dyspnea appeared in cardiopulmonary disease and the components under each dimension allowed separation of different patient groups. These findings may serve as a validation on the multiple dimensions of cardiopulmonary dyspnea.</p>

Diagnostic specificity of dynamic assessment and monitoring of spirometry in asthma / 中国医学科学院学报

<p><b>OBJECTIVE</b>To evaluate the diagnostic specificity of dynamic assessment and monitoring using a portable spirometer in diagnosis and differential diagnosis of asthma.</p><p><b>METHODS</b>We retrospectively reviewed the results of dynamic monitoring of spirometry in 145 symptomatic patients with physician-diagnosed asthma. Flow-volume curve and simultaneous symptoms and mood were measured in a fixed-time thrice-daily assessment schedule for 2 weeks. Patients were allowed to make additional measurements in case of symptom exacerbations.</p><p><b>RESULTS</b>The clinical data of 51 males and 94 females with a mean age of (39.1 +/- 13.0) years (ranged from 10 to 65 years) were analyzed. Duration of asthma before study was (6.7 +/- 9.9) years. Of 145 patients with physician-diagnosed asthma, 126 (87%) could be conclusively confirmed for a diagnosis of asthma. Asthma was misdiagnosed in 14 patients (9.7%). Overdiagnosis of asthma was observed in 5 patients (3.4%).</p><p><b>CONCLUSION</b>Dynamic assessment and monitoring using a portable spirometer by revealing variability and reversibility of airway obstruction may provide an additional tool for diagnosis and differential diagnosis of asthma.</p>

Fearful imagery induces hyperventilation and dyspnea in medically unexplained dyspnea / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Medically unexplained dyspnea refers to a condition characterized by a sensation of dyspnea and is typically applied to patients presenting with anxiety and hyperventilation without underlying cardiopulmonary pathology. We were interested to know how anxiety triggers hyperventilation and elicits subjective symptoms in those patients. Using an imagery paradigm, we investigated the role of fearful imagery in provoking hyperventilation and in eliciting symptoms, specifically dyspnea.</p><p><b>METHODS</b>Forty patients with medically unexplained dyspnea and 40 normal subjects matched for age and gender were exposed to scripts and asked to imagine both fearful and restful scenarios, while end-tidal PCO(2) (PetCO(2)) and breathing frequency were recorded and subjective symptoms evaluated. The subject who had PetCO(2) falling more than 5 mmHg from baseline and persisting at this low level for more than 15 seconds in the imagination was regarded as a hyperventilation responder.</p><p><b>RESULTS</b>In patients with medically unexplained dyspnea, imagination of fearful scenarios, being blocked in an elevator in particular, induced anxious feelings, and provoked a significant fall in PetCO(2) (P < 0.05). Breathing frequency tended to increase. Eighteen out of 40 patients were identified as hyperventilation responders compared to 5 out of 40 normal subjects (P < 0.01). The patients reported symptoms of dyspnea, palpitation or fast heart beat in the same fearful script imagery. Additionally, PetCO(2) fall was significantly correlated with the intensity of dyspnea and palpitation experienced during the mental imagery on one hand, and with anxiety symptoms on the other.</p><p><b>CONCLUSIONS</b>Fearful imagery provokes hyperventilation and induces subjective symptoms of dyspnea and palpitation in patients with medically unexplained dyspnea.</p>

Clinical application of portable spirometry in asthma / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the clinical applications of portable spirometry in asthma.</p><p><b>METHODS</b>Twenty patients with asthma were recruited from Peking Union Medical College Hospital. Flow-volume loop, simultaneous asthma symptoms, and mood were monitored three times a day for consecutive 14 days.</p><p><b>RESULTS</b>In patients with a normal daytime spirometry, marked decline of forced expiratory volume in one second (FEV1) and peak expiratory flow (PEF) were observed at night and/or in the early morning. A within subject correlation analysis between FEV1, PEF, and asthma symptoms showed that the correlation between symptoms and airway obstruction was found only in seven out of twenty patients (35%). Four patients (20%) reported many symptoms with nearly normal portable spirometry. Accordingly, their symptoms were not correlated with FEV1 and PEF. This group of patients was defined as over-perceivers. On the contrary, another two patients (10%) did not report any symptoms while obvious airways obstruction was recorded by a portable spirometry. These patients were defined as under-perceivers.</p><p><b>CONCLUSIONS</b>Dynamic monitoring of flow-volume loop with a portable spirometry is more accurate than routine lung function test in assessment of asthma severity. In addition, combined with simultaneous monitoring of symptoms, it would be of particularly helpful in identifying two specific types of asthma patients, e.g. over-perceivers and under-perceivers.</p>

Diagnosis and treatment of medically unexplained dyspnea / 中国医学科学院学报

Medically unexplained dyspnea refers to a group of patients presenting marked dyspnea without structural alterations of organs/systems after thorough examinations. This clinically neglected group of patients accounts for about 14% of patients with dyspnea in secondary health care. They appear very difficult to manage clinically. In this paper an organized approach used to diagnose medically unexplained dyspnea is presented. Breathing re-training is recommended as a therapy for those "difficult to treat patients".

Medically unexplained dyspnea in children: a review of 34 cases / 中华儿科杂志

<p><b>OBJECTIVE</b>Medically unexplained dyspnea is common in adult and accounts for 14% patients complaining of dyspnea. Its occurrence in children is seldom recognized. In the present paper, 34 children with medically unexplained dyspnea (age 10 to 18 years) seen in Peking Union Medical College Hospital from 1996 to 2002 are reported.</p><p><b>METHODS</b>The diagnosis of medically unexplained dyspnea was clinical: it was based on the presence of dyspnea and other complaints which cannot be explained by an organic disease. The patients answered Nijmegen questionnaire and state and trait anxiety (STAI), and performed hyperventilation provocation test. Twenty sessions of breathing therapy were applied and 13 out of 34 children were followed up after the therapy.</p><p><b>RESULTS</b>Among the children, 75% started to have symptoms at the age of 13 to 16 years, though the age of first episode could be as early as 8 years. In most of the cases, the course was chronic clinically. In addition to marked dyspnea, their clinical profile included symptoms of hyperventilation i.e. blurred vision, dizziness, tingling, stiff fingers or arm. The symptoms of anxiety were less frequent in children and accordingly the level of anxiety evaluated by means of STAI was lower in children compared to adult patients. The precipitating psychological factors appeared to be related to middle school competition. Pressure from exams, reprimand from stern and unsympathetic teachers coupled with high parental expectation could be emotionally damaging to psychologically susceptible children. Thirteen patients were followed up after 2-3 months of breathing therapy with emphasis on abdominal breathing and slowing down of expiration. After therapy, the sum score of the Nijmegen Questionnaire was markedly decreased. Dyspnea and symptoms of hyperventilation were improved. The level of anxiety was minimally modified.</p><p><b>CONCLUSION</b>The cases illustrated the need for careful diagnostic evaluation and treatment because of the high rate of chronicity of the disorder.</p>

Medically unexplained dyspnea: psychophysiological characteristics and role of breathing therapy / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Medically unexplained dyspnea occurs commonly in medical settings and remains poorly understood. This study was conducted to investigate the psychophysiological characteristics of medically unexplained dyspnea and the efficacy of breathing retraining for these patients.</p><p><b>METHODS</b>A group of patients with medically unexplained dyspnea were compared to patients with a variety of organic lung diseases and healthy subjects. In another group of patients, the influence of breathing therapy on complaints, anxiety, and breath-holding was evaluated for an average of 1.5 years.</p><p><b>RESULTS</b>Patients with medically unexplained dyspnea reported more intense dyspnea than patients with a variety of organic lung diseases. Additionally, they were anxious and presented a broad range of symptoms in daily life and under challenge, for instance voluntary hyperventilation. More than one third of them qualified for panic disorder. They had shorter breath-holding time at rest, less increase in breath-holding time and higher chances of showing a "paradoxical" decrease of breath-holding time after hyperventilation. A combination of PaO2, forced expiratory volume in one second (FEV1), and anxiety measures distinguished them from organic dyspnea. Breathing retraining profoundly improved their symptoms and decreased the level of state and trait anxiety. Moreover, they better tolerated the voluntary hyperventilation and the symptoms induced were also markedly decreased after therapy. Breath-holding time was prolonged and PetCO2 in a representative group of patients increased.</p><p><b>CONCLUSIONS</b>Patients with medically unexplained dyspnea appear to have the feature of a "psychosomatic" patient: an anxious patient with a wide variety of symptoms of different organ systems that do not have an organic basis. They can be distinguished from organic dyspnea using a small set of physiological and psychological measures. Breathing retraining turns out to be an effective therapy for those "difficult to treat patients".</p>

Assessment of pulmonary function in SARS patients during the convalescent period / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the pulmonary function in severe acute respiratory syndrome (SARS) patients during the convalescent period.</p><p><b>METHODS</b>Followup 89 outpatients of SARS. The follow-up study included interview, physical examination, and pulmonary function test.</p><p><b>RESULTS</b>The interval between hospital discharge and functional assessment was 1.75 +/- 0.53 months (0.5-3.4 months). Mild to moderate abnormalities in pulmonary function were found in 48 patients (53.9%). Diffusion capacity for carbon monoxide (DLco) was impaired in 38 patients (42.7%); in 7 patients (7.9%), lung function was restrictive defect combined DLco impairment; Other patterns of impairment were revealed in 3 patient. Dyspnea during acute phase and CT during the convalescent period were found to have significant influences on DLco and total lung capacity (TLC).</p><p><b>CONCLUSIONS</b>Diffusing capacity impairment as well as restrictive defect persist in convalescence SARS.</p>