Biomedical subjects

Thomas Ritz

Publications and source records attributed to Thomas Ritz.

At least 19 recordsLinked to original sources

PubMed2006

Reliability and validity of the Asthma Trigger Inventory applied to a pediatric population.

OBJECTIVE: To test the reliability and validity of the Asthma Trigger Inventory (ATI) applied to a pediatric population. METHOD: Children with asthma (N = 272, 56% male, age 7-17) and their primary caregivers answered together an asthma trigger inventory, ATI (Ritz, Steptoe, Bobb, Harris, & Edwards, 2006) developed for adults. Cronbach's alpha, principal component analysis (PCA), hierarchical regression, and correlations of the ATI subscales with skin prick tests, psychological questionnaires, and disease severity were used to assess the psychometric properties of the ATI. RESULTS: The ATI subscales demonstrated excellent reliability regardless of gender, race, socioeconomic status (SES), or age. PCA confirmed and replicated the theoretical structure of the ATI. Hierarchical multiple regressions illuminated the association of ATI subscales with demographics and asthma history. Evidence in support of construct validity was found in associations between ratings of triggering and disease severity and asthma-related quality of life (PAQLQ). Criterion validity for allergy triggering was partially supported by correlations between ATI animal allergens subscale and the cat dander skin prick test, and construct validity for emotional triggering by associations between the emotional trigger subscale score and the anxiety (STAIC) and depression (CDI, CDI-P, CDRS-R, and CBCL-I) scores. CONCLUSION: The ATI holds promise as a reliable, valid, and useful clinical and research tool to assess the type and degree of asthma triggering in a pediatric population (age 7-17) of varied gender, race, and SES.

Asthma↗

PubMed2006

Association of depression and anxiety with health care use and quality of life in asthma patients.

INTRODUCTION: Demographic factors, symptom severity, and psychopathology, in particular anxiety and depression, are known to influence health care use and quality of life in asthma. Because depression and anxiety are typically correlated, we sought to explore whether depression specifically is associated with health care utilization and quality of life when effects of anxiety are controlled for. METHOD: In a cross-sectional questionnaire study, 88 asthma patients (46 women; age range 27-70 years) reported on symptoms and treatment of their disease, as well as anxiety and depression (Hospital Anxiety and Depression Scale, HADS), general quality of life (Short Form 12 Health Survey Questionnaire, SF-12) and asthmatic-specific quality of life (Living with Asthma, LAQ). RESULTS: While no considerable associations between anxiety and health care use were found, the associations between higher scores in depression and hospital visits as well as days of corticosteroid intake were significant. Furthermore, considerable variance in all subscales of quality of life questionnaires was explained by higher scores in depression, even when controlling for anxiety. For anxiety scores these associations were comparable, except for physical well-being. CONCLUSION: Depression is an important issue in asthma, as it is substantially related to quality of life and intake of corticosteroids, and marginally to hospitalization. Routine screening for depression should be considered in hospital and primary care.

Adrenal Cortex Hormones↗

PubMed2006

Prevalence and correlates of asthma in children with internalizing psychopathology.

Our objective was to determine the prevalence rate of parent-reported asthma in children with internalizing disorders seeking psychological treatment, and to study the level of internalizing and externalizing problems in these patients compared to patients without asthma. Participants were 367 children (ages 5-18 years) with internalizing disorders seeking psychological treatment. Children's psychiatric diagnosis was established with the Anxiety Disorders Interview Schedule for DSM-IV-Child and Parent versions. Parents reported on their child's asthma diagnosis, medical history, and medication usage. Child psychopathology was assessed with the Child Behavior Checklist and by child self-report with the Multidimensional Anxiety Scale for Children and the Children's Depression Inventory. We assessed internalizing psychopathology of the mothers with the Depression Anxiety and Stress Scale. An additional diagnosis of parent-reported asthma was established for 15% of the children diagnosed with an Axis I internalizing disorder, a prevalence rate markedly higher than reported for current parent-reported childhood asthma in the U.S. population. Patients with asthma showed higher levels of internalizing problems than their nonasthmatic counterparts. Internalizing psychopathology was not higher for mothers of patients with asthma. Asthma is a significant problem within the population of patients with childhood internalizing disorders. It can be accompanied by a greater severity of internalizing problems and may require specific precautions in the treatment protocol. Though parent report of asthma diagnosis is commonly used in surveys of childhood asthma, our findings have to be viewed in the light of its limitations.

Adolescent↗

PubMed2006

Evaluation of a respiratory muscle biofeedback procedure-effects on heart rate and dyspnea.

Patients with respiratory diseases or anxiety frequently complain about dyspnea, which may be partly related to chronic tension of respiratory muscles and/or dynamic hyperinflation. In two experiments we tested a biofeedback technique that recorded electromyographic (EMG) activity from a bipolar surface electrode placement over the right external intercostal muscles with visual signal feedback. Healthy participants were tested in their ability to alter the signal. Heart rate was measured continuously throughout training trials. In the second experiment, dyspnea was rated on a modified Borg scale after each trial. Participants were able to increase their EMG activity considerably while heart rate and dyspnea increased substantially. Changes in EMG activity were achieved mostly by manipulating accessory muscle tension and/or altering breathing pattern. Thus, the technique is capable of altering respiratory muscle tension and associated dyspnea. Further studies may test the procedure as a relaxation technique in patients with respiratory disease or anxiety.

Adult↗

PubMed2006

Affective modulation of swallowing rates: unpleasantness or arousal?

OBJECTIVE: It has been observed that spontaneous swallowing rates are modulated by the affective state. Affect-induced swallowing may be an important biobehavioral factor in gastrointestinal disorders. However, previous studies failed to distinguish between pleasantness and arousal effects and did not analyze gender effects. METHOD: We analyzed swallowing rates in 42 participants (22 women) who viewed 3 blocks of 12 affective pictures preselected for inducing positive, negative, and neutral affect. Swallowing rate was measured by brief and rapid resistance increases in forced oscillation measurements indicating closure of the glottis. In addition, participants rated pleasantness and arousal for each individual picture. RESULTS: Cumulative swallowing rates were lower during positive and neutral than negative picture blocks. This effect was only observed in women. Ratings confirmed earlier findings with picture material. CONCLUSION: Both pleasantness and arousal interact to modulate swallowing rates. The role of gender in moderating affect-induced swallowing requires further research.

Adult↗

PubMed2005

Panic attack symptom dimensions and their relationship to illness characteristics in panic disorder.

Subtyping panic disorder by predominant symptom constellations, such as cognitive or respiratory, has been done for some time, but criteria have varied considerably between studies. We sought to identify statistically symptom dimensions from intensity ratings of 13 DSM-IV panic symptoms in 343 panic patients interviewed with the Anxiety Disorders Interview Schedule for DSM-IV Lifetime Version. We then explored the relation of symptom dimensions to selected illness characteristics. Ratings were submitted to exploratory maximum likelihood factor analysis with a Promax rotation. A three-factor solution was found to account best for the variance. Symptoms loading highest on the first factor were palpitations, shortness of breath, choking, chest pain, and numbness, which define a cardio-respiratory type (with fear of dying). Symptoms loading highest on the second factor were sweating, trembling, nausea, chills/hot flashes, and dizziness, which defines a mixed somatic subtype. Symptoms loading highest on the third factor were feeling of unreality, fear of going crazy, and fear of losing control, which defines a cognitive subtype. Subscales based on these factors showed moderate intercorrelations. In a series of hierarchical multiple regression analyses, the cardio-respiratory subscale was a strong predictor of panic severity, frequency of panic attacks, and agoraphobic avoidance, while the cognitive subscale mostly predicted worry due to panic. In addition, patients with comorbid asthma had higher scores on the cardio-respiratory subscale. We conclude that partly independent panic symptom dimensions can be identified that have different implications for severity and control of panic disorder.

Adult↗

PubMed2005

Voluntary hyperventilation in the treatment of panic disorder--functions of hyperventilation, their implications for breathing training, and recommendations for standardization.

Hyperventilation has numerous theoretical and empirical links to anxiety and panic. Voluntary hyperventilation (VH) tests have been applied experimentally to understand psychological and physiological mechanisms that produce and maintain anxiety, and therapeutically in the treatment of anxiety disorders. From the theoretical perspective of hyperventilation theories of anxiety, VH is useful diagnostically to the clinician and educationally to the patient. From the theoretical perspective of cognitive-behavior therapy, VH is a way to expose patients with panic disorder to sensations associated with panic and to activate catastrophic cognitions that need restructuring. Here we review panic disorder treatment studies using breathing training that have included VH. We differentiate the roles of VH in diagnosis, education about symptoms, training of breathing strategies, interoceptive exposure, and outcome measurement--discussing methodological issues specific to these roles and VH test reliability and validity. We propose how VH procedures might be standardized in future studies.

Anxiety Disorders↗

PubMed2005

Airways, respiration, and respiratory sinus arrhythmia during picture viewing.

Emotional stimuli can cause airway constriction; however, it is uncertain whether a dimensional or categorical model of emotion can better describe airway changes. Also, little is known about the affective modulation of respiration and vagal activity, which can influence airway tone. We studied changes in oscillatory resistance (Ros), respiration, and respiratory sinus arrhythmia (RSA) in asthmatics and controls during viewing of affective pictures eliciting anxiety, depression, disgust, happiness, contentment, erotic tension, or neutral affect. Ros, respiration, cardiac activity, and self-report were measured during picture presentations. Ros increased monotonically with picture unpleasantness mainly due to disgust pictures. RSA and respiratory timing parameters were particularly sensitive to erotic pictures. Differences between asthmatics and controls were minimal, suggesting that airway responses to unpleasant pictures are not specific to asthma.

Adult↗

PubMed2004

Behavioral interventions in asthma: biofeedback techniques.

OBJECTIVES: Biofeedback techniques have long been recommended as an adjunctive treatment for bronchial asthma. Techniques that target lung function directly, or indirectly by altering facial muscle tension, heart rate, heart rate variability (HRV) or inspiratory volume together with accessory muscle tension, have been proposed. We review evidence for the effectiveness of these biofeedback interventions and discuss the psychophysiological rationale behind individual techniques. METHOD: Controlled studies of biofeedback in asthma were retrieved using relevant search engines and reference lists of published articles. Effect sizes comparing intervention with control groups were calculated where appropriate. RESULTS: Most of the studies suffer from methodological inadequacies or poor reporting of methods and results. Interventions targeting respiratory resistance directly have yielded only small and inconsistent changes in lung function and are difficult to implement without producing dynamic hyperinflation. Biofeedback-assisted facial muscle relaxation as an indirect intervention has yielded mixed results across studies, with only half of the studies showing significant albeit very small and clinically irrelevant improvements in lung function. The underlying physiological assumptions of the technique are questionable in the light of current knowledge of respiratory physiology. For other indirect techniques, only preliminary evidence of small effects is available. CONCLUSION: Currently, there is little good evidence that biofeedback techniques can contribute substantially to the treatment of asthma.

Asthma↗

PubMed2004

Probing the psychophysiology of the airways: physical activity, experienced emotion, and facially expressed emotion.

This article reviews research on airway reactivity in health and asthma within a psychophysiological context, including the effects of physical activity, emotion induction, and manipulation of facial expression of emotion. Skeletal muscle activation leads to airway dilation, with vagal withdrawal being the most likely mechanism. Emotional arousal, in particular negative affect, leads to airway constriction, with evidence for a vagal pathway in depressive states and ventilatory contributions in positive affect. Laboratory-induced airway responses covary with reports of emotion-induced asthma and with lung function decline during negative mood in the field. Like physical activity, facial expression of emotion leads to airway dilation. However, these effects are small and less consistent in posed emotional expressions. The mechanisms of emotion-induced airway responses and potential benefits of emotional expression in asthma deserve further study.

Animals↗

PubMed2003

Do asthma patients in general practice profit from a structured allergy evaluation and skin testing? A pilot study.

BACKGROUND: Although allergy is central to the pathophysiology of asthma, little is known about the benefits of a structured approach to allergen diagnosis and management in primary care asthma patients. OBJECTIVES: We studied effects of a structured allergen evaluation and allergen avoidance advice combined with or without additional allergy skin testing on health status, illness perception, and lung function of asthma patients treated in general practice. METHOD: Fifty-four asthma patients were randomly assigned to three groups: (i) Standard asthma care with information on the stepwise treatment approach, a written action plan, and inhaler technique training; (ii) Additional structured allergen evaluation and avoidance advice; (iii) Additional structured allergen evaluation and avoidance advice based on skin prick test results. Patients were seen for one initial appointment at a primary care asthma clinic and a follow-up examination 3 months later. On both occasions, questionnaire measures of symptoms, illness perception, and the perceived control of asthma were administered. Lung function was measured by spirometry (PEF, FEV1). Perceived allergic asthma triggers, the trigger impact, and the trigger control were assessed in both intervention groups. RESULTS: Following intervention, a decrease in beta-adrenergic inhaler use, an increase in the perceived control of asthma, and a decrease in the bothering from asthma symptoms were observed for all three groups. Intervention groups showed a higher awareness of animal-allergic triggers, and the perceived control of asthma triggers was increased in the group receiving no skin tests. FEV1 showed an improvement in both intervention groups. CONCLUSION: Structured allergy evaluation and avoidance advice can improve lung function and the control of asthma in primary care. Further research is needed on the additional benefits of allergy skin testing.

Adolescent↗

PubMed2003

Behavioral interventions in asthma. Breathing training.

Breathing exercises are frequently recommended as an adjunctive treatment for asthma. A review of the current literature found little that is systematic documenting the benefits of these techniques in asthma patients. The physiological rationale of abdominal breathing in asthma is not clear, and adverse effects have been reported in chronic obstructive states. Theoretical analysis and empirical observations suggest positive effects of pursed-lip breathing and nasal breathing but clinical evidence is lacking. Modification of breathing patterns alone does not yield any significant benefit. There is limited evidence that inspiratory muscle training and hypoventilation training can help reduce medication consumption, in particular beta-adrenergic inhaler use. Breathing exercises do not seem to have any substantial effect on parameters of basal lung function. Additional research is needed on the psychological and physiological mechanisms of individual breathing techniques in asthma, differential effects in subgroups of asthma patients, and the generalization of training effects on daily life.

Asthma↗

PubMed2003

Breathing training for treating panic disorder. Useful intervention or impediment?

Breathing training (BT) is commonly used for treatment of panic disorder. We identified nine studies that reported the outcome of BT. Overall, the published studies of BT are not sufficiently compelling to allow an unequivocal judgment of whether such techniques are beneficial. This article discusses problems with the underlying rationale, study design, and techniques used in BT, and it identifies factors that may have determined therapy outcomes. The idea that hypocapnia and respiratory irregularities are underlying factors in the development of panic implies that these factors should be monitored physiologically throughout therapy. Techniques taught in BT must take account of respiration rate and tidal volume in the regulation of blood gases (pCO2). More studies are needed that are designed to measure the efficacy of BT using an adequate rationale and methodology. Claims that BT should be rejected in favor of cognitive or other forms of intervention are premature.

Breathing Exercises↗

PubMed2002

Airway response of healthy individuals to affective picture series.

We studied the effects of viewing pictures in three series of homogeneous affects on respiratory resistance. Results from prior studies had been equivocal with respect to modulation of resistance by affective valence or arousal. Forty-two healthy participants viewed three series of affective slides preselected for global categories of positive, neutral and negative valence. Oscillatory resistance (R(os)), time, volume and flow parameters of respiration, cardiac interbeat-interval, respiratory sinus arrhythmia, and skin conductance were measured throughout the picture series, and individual pictures were rated in pleasure, arousal and interest. During the slide presentation, R(os) increased with decreasing picture valence. Other physiological parameters did not parallel these changes. R(os) changes were restricted to the expiratory portion of the breathing cycle, thus suggesting a contribution of upper airway sites to the response. It is concluded that R(os) is modulated by affective valence when pictures are selected in global categories of positive, neutral and negative affect. Observed airway responses are probably less informative with respect to affect-induced exacerbation in lower airway disease.

Adult↗

PubMed2002

Guidelines for mechanical lung function measurements in psychophysiology.

Studies in psychophysiology and behavioral medicine have uncovered associations among psychological processes, behavior, and lung function. However, methodological issues specific to the measurement of mechanical lung function have rarely been discussed. This report presents an overview of the physiology, techniques, and experimental methods of mechanical lung function measurements relevant to this research context. Techniques to measure lung volumes, airflow, airway resistance, respiratory resistance, and airflow perception are introduced and discussed. Confounding factors such as ventilation, medication, environmental factors, physical activity, and instructional and experimenter effects are outlined, and issues specific to children and clinical groups are discussed. Recommendations are presented to increase the degree of standardization in the research application and publication of mechanical lung function measurements in psychophysiology.

Airway Resistance↗

PubMed2002

Effects of affective picture viewing and imagery on respiratory resistance in nonasthmatic individuals.

We studied the modulation of oscillatory resistance (R(os)) by viewing and imagery of affective pictures. Thirty nonasthmatic participants viewed 36 affective slides precategorized as positive, neutral, and negative in valence. Each picture was presented for 15 s, followed by an imagery epoch of 15 s. R(os), facial EMGs, respiration, skin conductance response, heart period, and respiratory sinus arrhythmia were measured throughout the session, as well as viewing time and ratings of pleasure, arousal, and interest. Increases of R(os) were observed for negative pictures, and little changes for positive or neutral pictures. Other physiological parameters did not mirror this response pattern, leaving no clear indication for a ventilatory or vagal origin of R(os) changes. Overall differences between behavioral contexts of visual processing and imagery revealed evidence for a coupling of cardiac and respiratory responses, which included changes in R(os). The findings in R(os) are discussed in the light of earlier discrepant findings on the affective modulation of airway resistance and cardiac activity.

Adult↗

PubMed2001

Experimentally induced emotions, facial muscle activity, and respiratory resistance in asthmatic and non-asthmatic individuals.

We studied the effects of emotion induction on total respiratory resistance, and their relationship with cardiac vagal activity and facial muscle activity in asthma. Groups of 20 asthmatic and 20 non-asthmatic participants were exposed to series of happy and depressing pictures or self-referent Velten statements. Facial electromyographic activity over corrugator supercilii, orbicularis oculi, and zygomaticus major regions was recorded during periods of presentation and imagery of each stimulus. Following each stimulus series, mood, respiratory resistance, ventilation, and cardiac activity including respiratory sinus arrhythmia (RSA) were recorded. Significant increases of respiratory resistance were observed in asthmatic patients following depressing stimulation. Resistance increases were positively correlated with RSA and heart period. No substantial group differences were found in facial response to emotional stimuli. Changes in facial target muscle sites during positive stimulation were inversely correlated with RSA following stimulation. We conclude that respiratory resistance increases in asthmatics following depressing stimulation are dependent on vagal activity. Greater facial muscle activation during emotional stimulation can reduce vagal activation, which is consistent with claims in the clinical literature of the benefits of emotional expression in asthma.

Journal Article↗

PubMedDate not supplied

End-tidal pCO2 in blood phobics during viewing of emotion- and disease-related films.

OBJECTIVE: Many patients with blood, injection, and injury (BII) phobia respond to specific stimuli with vasovagal dysregulation and fainting. However, little is known about the role of hyperventilation in the distress of these patients. Hyperventilation, defined by subnormal arterial pCO2 levels, induces anxiety and may promote the development of fainting. We studied end-tidal pCO2 in 12 patients with BII phobia and 14 nonanxious controls during presentation of emotional films. METHOD: Ten film clips were shown, two in each of 5 categories: pleasant, unpleasant, neutral, BII-related (surgery), and asthma-related (portraying labored breathing). For each subject, two subsets were created, each containing one clip from each category. For one subset, the instruction was simply to view the film, and for the other subset, to view the film while tensing the leg muscles. PCO2, heart rate, blood pressure, and leg electromyogram were recorded continuously during viewing, and self-report of symptoms and emotion was collected after each film. RESULTS: Patients reported the greatest anxiety and disgust during surgery films. PCO2 was relatively stable throughout all categories except surgery films, during which minima were below 30 mm Hg, indicating significant hypocapnia. Cardiovascular variables suggested biphasic patterns in two patients with BII phobia. These patients, together with one additional patient and one control who were close to fainting after or during one surgery film, also showed a marked fall in pCO2) Leg muscle tension raised heart rate and systolic blood pressure for all films, but was not related to near-fainting or endurance in surgery film viewing. CONCLUSION: Hyperventilation is part of the fear response of patients with BII phobia, but was transitory in experimental fear induction using surgery films. Its role in real-life exposure and fainting deserves further study.

Adult↗