Biomedical subjects

B Garssen

Publications and source records attributed to B Garssen.

At least 19 recordsLinked to original sources

PubMed1997

Hyperventilation syndrome: an elegant but scientifically untenable concept.

The concept of hyperventilation and the principle of a vicious circle provide an elegant explanation for the development of a wide range of somatic and psychological symptoms, the so-called hyperventilation syndrome (HVS). The model has a high degree of credibility and has led to the development of therapeutic interventions that appeared beneficial. However, recent investigations dismiss hyperventilation as an important symptom-producing mechanism. First, the hyperventilation provocation test appears to be invalid as a diagnostic test. Second, studies using ambulant monitoring of pCO2 demonstrate that the vast majority of real-life attacks are not attended by decreases in pCO2. Third, the evaluation of therapy outcome studies indicate that the beneficial effect of breathing retraining is probably not mediated by reducing the tendency to hyperventilate. We conclude that a diagnosis of HVS should be avoided.

Humans↗

PubMed1996

Double-blind placebo-controlled study of the hyperventilation provocation test and the validity of the hyperventilation syndrome.

BACKGROUND: Hyperventilation syndrome (HVS) describes a set of somatic and psychological symptoms thought to result from episodic or chronic hyperventilation. Recognition of symptoms during the hyperventilation provocation test (HVPT) is the most widely used criterion for diagnosis of HVS. We have investigated the validity of the HVPT and of the concept of HVS. METHODS: In a randomised, double-blind, crossover design, the ability of 115 patients with suspected HVS to recognise symptoms during the HVPT was compared with the ability to recognise symptoms during a placebo test (isocapnic overbreathing, with carbon dioxide levels maintained by manual titration). 30 patients who had positive results on the HVPT underwent ambulatory transcutaneous monitoring of pCO2 to ascertain whether they hyperventilated during spontaneous symptom attacks. FINDINGS: Of the 115 patients who underwent the HVPT and the placebo test, 85 (74%) reported symptom recognition during the HVPT (positive diagnosis HVS). Of that subset, 56 were also positive on the placebo test (false-positive), and 29 were negative on the placebo test (true-positive). False-positive and true-positive patients did not differ in symptom profile or in physiological variables. During ambulatory monitoring (15 true-positive, 15 false-positive) 22 attacks were registered. Transcutaneous end-tidal, pCO2 decreased during only seven. The decreases were slight and apparently followed the onset of the attack, which suggests that hyperventilation is a consequence rather than a cause of the attack. There were no apparent differences between false-positive and true-positive patients. INTERPRETATION: The HVPT is invalid as a diagnostic test for HVS. Hyperventilation seems a negligible factor in the experience of spontaneous symptoms. The term HVS should be avoided.

Adult↗

PubMed1996

Continuing pain education in nursing: a literature review.

Twelve studies on the effects of pain programmes for nurses were reviewed. Most of the programmes focused on aspects of pain, pain medication or pain assessment. Only two programmes (Ferrell et al., 1993, J. Pain Symptom Management, Vol. 8, No. 8, pp. 549-556; Sofaer, 1983, Nurs. Times, Vol. 79, No. 47, pp. 38-42; 1984, Ph.D. Thesis, University of Edinburgh) also paid attention to non-pharmacological nursing interventions. Randomized control groups, established measurement instruments, testing statistics, and long-term follow-up measurements, were not often used in the effect evaluation of the programmes. Effects reported on both nurses and patients were for the most part positive. Given the small number of studies and their methodological limitations, further research into the effectiveness of continuing pain education in nursing is indicated.

Data Interpretation, Statistical↗

PubMed1996

Adjustment to breast cancer: the psychobiological effects of psychosocial interventions.

This review focuses on the effects of psychosocial interventions on psychological and biological functioning of breast cancer patients. Once in their lifetime, one out of eleven women receive a diagnosis of breast cancer. A diagnosis of breast cancer is a severe stressful life event with profound consequences on all aspects of human life. Whether a woman will regain emotional balance and accept the idea of living with a potentially life threatening disease depends on her psychological resiliency. Provision of psychosocial interventions can improve these women's coping abilities and reduce emotional distress and feelings of isolation, and improve psychosexual functioning. Additionally, there exists some evidence that psychotherapy may prolong survival. Prolongation of survival may be related, in part, to an increase in certain aspects of immune function (e.g., natural killer cell activity). This is plausible because the function of the immune system seems to be related to mammary tumor growth. Therefore, future research should examine the degree to which the effects on mammary tumor growth relate to immune system changes.

Adaptation, Psychological↗

PubMed1996

Effects of a pain programme on nurses' psychosocial, physical and relaxation interventions.

The effectiveness of a continuing education programme on pain assessment and management was investigated in 106 surgical cancer nurses. It was found that the programme led to a more positive attitude towards physical and relaxation interventions (such as the use of relaxation, distraction and massage techniques). In addition, an increase in the duration and quality of psychosocial interventions (provision of information, emotional support, and promotion of autonomy) was established. Furthermore, the programme resulted in an increase in the quality of physical and relaxation interventions. However, the programme did not lead to more positive attitudes towards psychosocial interventions, or to increases in the numbers of psychosocial, physical and relaxation interventions.

Adult↗

PubMed1996

The low specificity of the Hyperventilation Provocation Test.

The Hyperventilation Provocation Test (HVPT) has become a routine procedure in the diagnosis of hyperventilation syndrome (HVS). During an HVPT the patient voluntarily overbreathes for several minutes to produce hypocapnia. The test is considered positive if the induced symptoms are recognized by the patient as similar to those experienced in daily life. The present study tests the assumption that hypocapnia is the primary trigger for symptoms during an HVPT. In a randomized double-blind crossover design. 115 patients suspected of HVS and 40 healthy controls performed an HVPT and a placebo test (PT, isocapnic overbreathing). The HVPT induced more symptoms than the PT, especially more neuromuscular symptoms, cerebral symptoms, paresthesias, and temperature sensations. However, the absolute difference between the number of symptoms induced by the HVPT and PT was small. In patients, the PT induced 66% of symptoms induced by the HVPT. In the control group this percentage was 60%. The low specificity of the HVPT implies that symptom recognition during the HVPT is invalid as a diagnostic criterion for HVS.

Adult↗

PubMed1996

Application of the multidimensional fatigue inventory (MFI-20) in cancer patients receiving radiotherapy.

In this paper the psychometric properties of the multidimensional fatigue inventory (MFI-20) are established further in cancer patients. The MFI is a 20-item self-report instrument designed to measure fatigue. It covers the following dimensions: general fatigue, physical fatigue, reduced activity, reduced motivation and mental fatigue. The instrument was used in a Dutch and Scottish sample of cancer patients receiving radiotherapy. The dimensional structure was assessed using confirmatory factor analyses (Lisrel's unweighted least-squares method). The hypothesised five-factor model appeared to fit the data in both samples (adjusted goodness of fit; AGFI: 0.97 and 0.98). Internal consistency of the separate scales was good in both the Dutch and Scottish samples with Cronbach's alpha coefficients ranging from 0.79 to 0.93. Construct validity was assessed by correlating the MFI-20 to activities of daily living, anxiety and depression. Significant relations were assumed. Convergent validity was investigated by correlating the MFI scales with a visual analogue scale measuring fatigue and with a fatigue-scale derived from the Rotterdam Symptom Checklist. Results support the validity of the MFI-20. The highly similar results in the Dutch and Scottish sample suggest that the portrayal of fatigue using the MFI-20 is quite robust.

Adolescent↗

PubMed1996

Hyperventilation and panic attacks.

OBJECTIVE: Hyperventilation has been posed as an important symptom-producing mechanism in panic attacks. Some arguments and experimental findings, such as the possibility of inducing panic symptoms by voluntary hyperventilation in panic disorder patients, seem to favor this suggestion. This study was undertaken to clarify the role of hyperventilation in panic disorder. Long-term ambulatory measurement of transcutaneous arterial CO2 pressure (PCO2) offers an opportunity to test directly the co-occurrence of panic and hyperventilation under natural conditions. METHOD: Transcutaneous PCO2 was measured during three to four sessions of approximately 7 hours each in 28 panic disorder patients. Patients were instructed to expose themselves to fear-provoking situations and to press a button as soon as they experienced panic. One-half of the patients experienced one or more panic attacks during these sessions. RESULTS: A decrease in PCO2 was observed during only one of the 24 registered panic attacks that lasted at least 3 minutes. Even during this particular attack, the degree of hyperventilation was not impressive. CONCLUSIONS: These findings indicate that the hypothesis that hyperventilation is an important symptom-producing mechanism in panic may be dismissed.

Adult↗

PubMed1995

The Multidimensional Fatigue Inventory (MFI) psychometric qualities of an instrument to assess fatigue.

The Multidimensional Fatigue Inventory (MFI) is a 20-item self-report instrument designed to measure fatigue. It covers the following dimensions: General Fatigue, Physical Fatigue, Mental Fatigue, Reduced Motivation and Reduced Activity. This new instrument was tested for its psychometric properties in cancer patients receiving radiotherapy, patients with the chronic fatigue syndrome, psychology students, medical students, army recruits and junior physicians. We determined the dimensional structure using confirmatory factor analyses (LISREL's unweighted least squares method). The hypothesized five-factor model appeared to fit the data in all samples tested (AGFIs > 0.93). The instrument was found to have good internal consistency, with an average Cronbach's alpha coefficient of 0.84. Construct validity was established after comparisons between and within groups, assuming differences in fatigue based on differences in circumstances and/or activity level. Convergent validity was investigated by correlating the MFI-scales with a Visual Analogue Scale measuring fatigue (0.22 < r < 0.78). Results, by and large, support the validity of the MFI.

Adult↗

PubMed1995

Voluntary hyperventilation: the influence of duration and depth on the development of symptoms.

Hyperventilation is considered an important factor in the development of somatic symptoms or even panic attacks, though its role has recently been disputed. Arguments are often based on findings from the so-called Hyperventilation Provocation Test (HVPT), which is a procedure consisting of voluntarily overbreathing. The HVPT has been widely used for diagnosing Hyperventilation Syndrome and for experimentally eliciting panic attacks. Almost no attention, however, has been paid to standardizing the test and determining critical values with respect to depth and duration of hyperventilation. In the present study, symptom development was examined in 16 healthy subjects who underwent four HVPTs that differed in depth of hyperventilation (end-tidal PCO2 < 2.4 kPa or < 1.9 kPa), as well as duration of hyperventilation (2 or 5 min). Both depth and duration appeared to have an independent effect on the development of symptoms. In the 5-min condition, symptoms appeared mainly within the first 3 min. To be sure that the HVPT is long enough and deep enough to elicit symptoms in most people, a minimum duration of 3 min is advised, with end-tidal PCO2 decreasing to at least 1.9 kPa or dropping well over 50% of baseline.

Adult↗

PubMed1995

Determinants of changes in nurses' behaviour after continuing education: a literature review.

Nursing continuing-education programmes may differ in the extent to which they affect nursing practice. Differences may be explained by characteristics of the participants' background, the programme itself, teacher(s), relationship between participants, relationship between participants and teacher(s), physical environment during the programme, participants' social system, knowledge, skills and attitudes, and intention to change. In this literature review, a model is presented which integrates these variables and which may be used to explain why continuing-education programmes have no, little or considerable effect. On the basis of current scientific knowledge, colleagues' and superiors' support emerges as the most important determinant of behavioural changes in nursing practice.

Clinical Competence↗

PubMed1994

Continuous monitoring of panic.

Data on naturally occurring panic attacks were gathered through continuous self-monitoring for 94 patients suffering from panic disorder with agoraphobia. A total of 1276 panic attacks were collected. In this article various aspects of panic attacks, including severity, duration and time of onset and situations in which panic occurs are addressed. In addition, the symptoms of panic were investigated, examining the (in)variability of attacks within each patient and the patterning of symptoms in the entire group of patients. The most important findings were as follows: attacks occurred predominantly in nonphobic situations; nocturnal panic attacks were generally more severe than attacks during the day; symptom patterns across various attacks, stemming from the same patient, were rather variable; and finally, a substantial number of the attacks (40%) did not meet the DSM-III-R criteria for number of symptoms.

Adult↗

PubMed1993

Fatigue in cancer patients.

In this paper an overview is presented on what is currently known of fatigue in cancer. Fatigue is considered to be a multi-dimensional concept, that should be measured as such. However, fatigue has been assessed mostly by single items in general symptom checklists. The few specific instruments that have been used in cancer patient populations are discussed. The majority of cancer patients, about 70%, report feelings of fatigue during radio- or chemotherapy. Follow-up results show that, at least for some diagnoses, patients remain fatigued long after treatment has ended. Somatic and psychological mechanisms that have been proposed to explain fatigue are discussed. It is argued that the significance of the results obtained on fatigue as a symptom in cancer depends on comparison with other patient and non-patient populations. Also the occurrence of a response-shift has to be considered, leading to under reporting of fatigue. Finally, possible interventions to decrease feelings of fatigue are presented.

Fatigue↗

PubMed1993

[When is continuing education useful? A literature analysis of determinants for behavioral change in nurses who finished continuing education].

Nursing continuing education programmes may differ in the extent in which they affect nursing practice. Differences may be explained by: background characteristics of the participant; characteristics of the programme itself; characteristics of the teacher(s); characteristics of the relationship between the participant and the teacher(s); characteristics of the relationship between the participant and the other participants; characteristics of the social system; knowledge, skills and attitudes; and intention of the participant to change behavior. In this literature review, a model is presented in which these variables are integrated and which may be used to explain why continuing education programmes have no, little or much effect. On the basis of the present scientific knowledge, support from colleagues, supervisors and administrators (a characteristic of the social environment) emerges as a very important determinant of positive behavior changes in nursing practice.

Attitude of Health Personnel↗

PubMed1992

The role of hyperventilation in panic disorder: a response to Ley (1991)

Ley (Behaviour Research and Therapy, 29, 301-304, 1991) provided a reinterpretation of experimental findings on the efficacy of breathing retraining plus cognitive restructuring in reducing the symptomatology of patients with panic disorder with agoraphobia which were presented in a 1989 article in this journal. On the basis of his reinterpretation, they concluded that our findings supported the central role of hyperventilation in panic attacks. Ley's arguments are discussed and we conclude that his reinterpretation provides new arguments against a hyperventilation theory of panic. Furthermore, recent evidence from empirical studies does not support a central role for hyperventilation in panic attacks.

Arousal↗

PubMed1992

A follow-up study on short-term treatment of agoraphobia.

The differential effectiveness of three treatment packages for agoraphobia was tested. Patients received one of three short-term treatments: Breathing Retraining and Cognitive Restructuring, graded Self-Exposure in vivo, or a combination of both. No differential effects were found between the treatment conditions at posttest and at an 18 months follow-up. Improvement at follow-up assessment was associated with whether patients had further treatment during the follow-up period. No relationship was found between further improvement and demographic variables, pre- and posttest scores on psychological questionnaires or the use of medication at follow-up. Implications of these findings are examined.

Adult↗

PubMed1990

[Criteria for differential diagnosis in cardial symptoms; left- or right-sided chest pain?].

We studied the localization of pain in the acute phase of myocardial infarction in comparison with localization in non-cardiac chest pain. Myocardial infarction patients could not be differentiated from patients with non-cardiac chest pain in localization of pain on mid-chest, left side of the chest and left arm. However, myocardial infarction patients reported pain on the right side of the chest and in the right arm twice as often as non-cardiac chest pain patients. Results are similar when patients indicated the localization of the pain symptoms on attending the Emergency Coronary Care Unit, or when asked five days later. Pain symptoms on the right side of the chest and the right arm differentiate better between myocardial infarction and non-cardiac chest pain than the 'classical' symptom pattern.

Acute Disease↗

PubMed1990

Symptom reporting during voluntary hyperventilation and mental load: implications for diagnosing hyperventilation syndrome.

Hyperventilation is considered an important factor in the production of a variety of somatic symptoms. This complex of symptoms is called the Hyperventilation Syndrome (HVS). Recognition of symptoms during the hyperventilation provocation test (HVPT) is a widely used criterion for diagnosing HVS. The validity of this criterion is tested in the present study. Twenty-three patients suspected of HVS performed a HVPT (hyperventilation during 3 min) and a mental load task (Stroop Color Word Test; CWT). It appeared that about the same number of patients (61%) recognized symptoms during the HVPT as during the CWT (52%), despite severe hypocapnia in the first test and normocapnia in the second. Reporting of symptoms was significantly related to psychological state and trait measures (SCL-90 and STAI scores) and unrelated to the degree of hypocapnia. These data have far reaching consequences, as they not only undermine the validity of the HVPT, but also question the tenability of the concept of HVS.

Agoraphobia↗