Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0085383 (hypocapnia)
 1,697 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The Asthma Symptom Checklist (ASC), describing the subjective symptoms reported to occur during asthmatic attacks, has been developed previously. In the present study, the ASC key cluster solution was replicated and refined within a sample of 374 asthmatic inpatients. All of the original symptom categories were reporduced, including two mood categories, Panic-Fear and Irritability, a Fatigue category, and two somatic categories. Hyperventilation-Hypocapnia and Airway Obstruction. Two refinements were notable: (1) The Airway Obstruction category was empirically divided into two conceptually clear components, Dyspnea anc Congestion, and (2) three secondary mood categories, Worry, Loneliness, and Anger, were identified, which describe a continuum of mood between the polar extremes of panic and irritability. Of the symptom categories, only Panic-Fear was related to the intensity of the discharge drug regimens recommended 2 to 6 mouths after ASC administration. Panic-Fear scores were independent of pulmonary function measurements. A combined index based on pulmonary functions and panic-fear yielded the best prediction of discharge steroid regiments. Finally, those physicians rated highest in "sensitivity" to their patients by their supervisors prescribed less steroids overall, but most frequently prescribed discharge steriod regimens in relation to their patients' Panic-Fear scores. In contrast, physicians rated lower on sensitivity prescribed higher steroid regimens overall, but based these drug recommendations more cleary on objective pulmonary functioning, and not in relation to their patients' Panic-Fear scores. The results strongly suggest that the ASC Panic-Fear scale is associated with coping behaviors that importantly affect the patient's overall clinical picture by increasing the apparent severity of the asthma, thereby leading to intensified treatment. The findings stress the need to evaluate independently the objective medical condition and subjective symptomatology with its related coping behavior, in order to direct appropriate modes of therapy to each.
 ...
PMID:Obervations on subjective symptomatology, coping behavior, and medical decisions is asthma. 40 66

The purpose of this study was to compare psychologic and physiologic variables during intense dyspnea to those at times of no or low dyspnea in people with asthma. Thirty-six adults ranging from 19 to 76 years old were tested when they first came to the emergency department in acute dyspnea and again when they had no or low dyspnea just prior to discharge. Clinical signs found to be higher during high dyspnea than low dyspnea were respiratory rate, pulse, wheezing, and accessory muscle use. Peak expiratory flow rates and oxygen saturation were significantly lower, while anxiety, depression, somatization, and hostility were higher during times of high dyspnea. The panic/fear, fatigue, dyspnea, hyperventilation/hypocapnia, congestion, and rapid breathing subscales of the Asthma Symptom Checklist were also higher during high dyspnea compared to low dyspnea.
 ...
PMID:Psychologic and physiologic aspects of acute dyspnea in asthmatics. 185 43

Many physicians believe that the hyperventilation syndrome is invariably associated with anxiety or undiagnosed organic disease such as asthma and pulmonary embolus, or both. Twenty one patients referred by specialist physicians with unexplained somatic symptoms and unequivocal chronic hypocapnia (resting end tidal Pco2 less than or equal to 4 kPa (30 mm Hg) on repeated occasions during prolonged measurement) were investigated. All but one complained of inability to take a satisfying breath. Standard lung function test results and chest radiographs were normal in all patients, but histamine challenge showed bronchial hyper-reactivity in two of 20 patients tested, and skin tests to common allergens were positive in three of 18. Ventilation-perfusion scanning was abnormal in a further three of 15 patients studied, with unmatched perfusion defects in two and isolated ventilation defects in one. None of the 21 had thyrotoxicosis, severe coronary heart disease, or other relevant cardiovascular abnormalities. Ten of the 21 patients were neurotic and suffered from chronic psychiatric disturbance characterised by anxiety, panic, and phobic symptoms. The remainder had no detectable psychiatric disorders but reported proportionately more somatic than anxiety symptoms. Severe hyperventilation can occur in the absence of formal psychiatric or detectable respiratory or other organic abnormalities. Asthma and pulmonary embolus must be specifically excluded.
 ...
PMID:Respiratory and psychiatric abnormalities in chronic symptomatic hyperventilation. 392 4

Hypoxia and hypocapnia can cause broncho-constriction in human subjects, and this could have a bearing on performance at high altitude. The object of this study was to examine how pulmonary ventilatory functions during high-altitude trekking. This study is a cohort study on spirometric parameters at different altitudes. Fifty six healthy male volunteers from a university student population were enrolled in the study (ages 22.9+/-5.3 years). Pulmonary function was assessed with a Spirolab II in all participants before ascending at baseline (1150 meter), after ascending at different altitudes (2850, 4150 meter), and after descending at sea level during a 3-day trek in Sialan Mount. This study indicates that in an actual trek, ascending results in significant decrease in forced vital capacity (FVC). FVC significantly decreased with increasing altitude from baseline level and at the sea level it was significantly less than baseline level. Peak flow increased with increasing altitude from baseline (1150 m) to 2850 m and decreased with decreasing altitude (p<0.01). Maximal midexpiratory flow rate (FEF 25-75%) and forced expiratory volume in 1 second to forced expiratory volume ratio (FEV1.0%) significantly increased with increasing and decreasing altitude from baseline level (p<0.001). There was no significant change in FEV1. It could be concluded that changes in some pulmonary ventilatory parameters were proportional to the magnitude of change in altitude during a high-altitude trek. These changes are significant at the beginning of ascending.
Iran J Allergy Asthma Immunol 2008 Jun
PMID:Pulmonary function parameters changes at different altitudes in healthy athletes. 1855 9

In the absence of other explanations, exercise-induced dyspnea is often labeled as a manifestation of asthma. The aim of this study was to use exercise provocation in cold air among patients with exercise-induced dyspnea, but without any bronchoconstriction, in order to study induced symptoms and different physiological parameters and to measure the possible influence of exercise in cold air on capsaicin cough sensitivity. Eleven patients with exercise-induced dyspnea but no asthma, along with 11 healthy controls, performed a capsaicin inhalation provocation on two occasions. One of these provocations was preceded by an exercise provocation in a cold chamber. Number of coughs, airway symptoms, spirometry, respiratory rate, pulse rate, end-tidal CO(2), and PSaO(2) were registered. During exercise, the patients coughed more than the controls and also had more airway symptoms. After exercise provocation, spirometry values remained unchanged, but capsaicin cough sensitivity was increased and end-tidal CO(2) decreased among the patients, both in comparison to the controls and in comparison to the patients themselves prior to exercise. Exercise-induced dyspnea may be associated with hypocapnia from hyperventilation and increased capsaicin cough sensitivity. The diagnosis of exercise-induced asthma should be questioned when the patient has no signs of bronchoconstriction.
J Asthma 2008 Oct
PMID:Dyspnea from exercise in cold air is not always asthma. 1895 Dec 64

We present a woman with heterozygous carnitine palmitoyl transferase 2 (CPT-2) deficiency who in the last 6 months suffered from episodic dyspnea and choking. Symptoms could not be attributed to her muscular energy defect, since heterozygous CPT-2 deficiency is usually asymptomatic or causes only mild muscle fatigability. Myopathy is usually triggered by concurrent factors, either genetic (additional muscle enzymes defects) or acquired (metabolic stress). The patient was referred to our respiratory clinic for suspect bronchial asthma. Spirometry showed mild decrease in inspiratory flows. Methacholine challenge was negative. Dyspnea was triggered by hyperventilation-induced hypocapnia, which produced marked decrease in airflow rates, particularly in inspiratory flows, consistent with laryngospasm. Nutritional assessment of the patient showed low serum level of calcium and vitamin D, attributable to avoidance of milk and dairy products for lactose intolerance and to insufficient sunlight exposure. After calcium and vitamin D supplementation episodic laryngospasm disappeared and hypocapnic hyperventilation test induced very mild change in airflow rates. Calcium and vitamin D deficiency may favour laryngeal spasm mimicking asthma, particularly in subjects with underlying myopathy.
Allergy Asthma Immunol Res 2014 May
PMID:Laryngeal spasm mimicking asthma and vitamin d deficiency. 2484 4

Asthma is a common illness throughout the world that affects the respiratory system function, i.e., a system whose operational adequacy determines the respiratory gases exchange. It is therefore expected that acute severe asthma will be associated with respiratory acid-base disorders. In addition, the resulting hypoxemia along with the circulatory compromise due to heart-lung interactions can reduce tissue oxygenation, with a particular impact on respiratory muscles that have increased energy needs due to the increased workload. Thus, anaerobic metabolism may ensue, leading to lactic acidosis. Additionally, chronic hypocapnia in asthma can cause a compensatory drop in plasma bicarbonate concentration, resulting in non-anion gap acidosis. Indeed, studies have shown that in acute severe asthma, metabolic acid-base disorders may occur, i.e., high anion gap or non-anion gap metabolic acidosis. This review briefly presents studies that have investigated acid-base disorders in asthma, with comments on their underlying pathophysiology.
 ...
PMID:Acid-Base Disturbances in Patients with Asthma: A Literature Review and Comments on Their Pathophysiology. 3102 65