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Biomedical subjects

K Verburg

Publications and source records attributed to K Verburg.

9 recordsLinked to original sources
PubMed1998

Reliability of the 35% carbon dioxide panic provocation challenge.

The objective of this study was to determine the test-retest reliability of the 35% carbon dioxide (CO2) panic provocation challenge. Thirty patients with panic disorder were included in this study. Twenty-four patients were challenged twice, with 1 week between the two challenges. Six patients dropped out after the first test. The 35% CO2 challenge appeared to have a good test-retest reliability; both on induced subjective anxiety, measured on a Visual Analogue Scale for Anxiety (VAS-A), and induced panic symptoms, measured with a Panic Symptom List. Assessing the state of anxiety immediately after the challenge gave the most reliable results. Calculating increase in anxiety from the pre- and post-scores on the VAS-A rendered less reliable scores. This study completes a series of studies in which the criteria for an ideal model of panic are tested for the 35% CO2 challenge. Apart from an absolute specificity for panic disorder, the challenge meets these criteria.

Adult↗
PubMed1998

Comorbid depressive disorder increases vulnerability to the 35% carbon dioxide (CO2) challenge in panic disorder patients.

BACKGROUND: The hypothesis of this study was that panic disorder patients with a comorbid depressive disorder would be less vulnerable to the 35% CO2 panic provocation challenge than panic disorder patients without a comorbid depressive disorder. This hypothesis was based on findings from ventilatory response studies in depressive patients. METHODS: Twelve panic disorder patients with and 23 panic disorder patients without a comorbid depressive disorder were challenged. RESULTS: Panic disorder patients with a comorbid depressive disorder scored significantly higher on ratings of subjective anxiety and panic symptoms induced by the challenge. CONCLUSIONS: A comorbid depressive disorder appeared to increase the vulnerability of panic disorder patients to this panic provocation. LIMITATION: We did find significant differences, but these differences did not confirm the original hypothesis. CLINICAL RELEVANCE: Our results support clinical data that show that a comorbid depressive disorder correlates with an increased severity of panic disorder.

Adult↗
PubMed1996

Alprazolam premedication and 35% carbon dioxide vulnerability in panic patients.

A group of 20 patients who met the DSM-III-R criteria for panic disorder with or without agoraphobia underwent a 35% carbon dioxide (CO2) challenge after either 1 mg alprazolam or placebo in a double-blind, randomized, cross-over design. Despite the anxiolytic potential of alprazolam, it produced no significant effects on CO2-induced anxiety and panic symptomatology when compared to placebo.

Adult↗
PubMed1996

Fluvoxamine attenuates panic induced by 35% CO2 challenge.

BACKGROUND: The authors investigated whether 6 weeks of treatment with fluvoxamine would decrease the anxiogenic response to the 35% CO2 challenge in 11 patients with DSM-III-R panic disorder with agoraphobia. METHOD: The patients underwent a 35% CO2 challenge at baseline and again after 6 weeks of fluvoxamine treatment. RESULTS: The anxiogenic effect of CO2 was significantly (p < .05) reduced during fluvoxamine treatment. CONCLUSION: The results suggest a relationship between the anxiogenic effect of CO2 and the therapeutic effect of fluvoxamine.

Adult↗
PubMed1995

Respiratory disorders as a possible predisposing factor for panic disorder.

150 consecutive anxiety patients completed a specially designed questionnaire which asked for the occurrence of respiratory and other somatic disorders before the onset of their anxiety disorder. The sample was divided into 82 panic disorder patients and 68 other anxiety patients serving as controls. Panic disorder patients had a significantly higher prevalence of respiratory diseases before the onset of their anxiety disorder than controls (42.7 vs. 16.2%). This higher prevalence was mainly due to a higher prevalence of bronchitis (26.8 vs. 8.8%). Differences in numbers of respiratory disorders mentioned appeared not to result from a tendency to hypochondria.

Adult↗
PubMed1995

Discrimination between panic disorder and generalized anxiety disorder by 35% carbon dioxide challenge.

OBJECTIVE: The authors' goal was to determine whether 35% carbon dioxide (CO2) challenge would discriminate between patients with panic disorder and patients with other anxiety disorders. METHOD: Nine patients with panic disorder and nine with generalized anxiety disorder underwent the 35% CO2 challenge. RESULTS: Patients with panic disorder experienced a significantly stronger increase in subjective anxiety than patients with generalized anxiety disorder. However, increases in panic symptom scores were high in both groups. CONCLUSIONS: These results suggest that a large increase in subjective anxiety due to the CO2 challenge is specific for patients with panic disorder but that an increase in panic symptoms is not.

Adult↗
PubMed1994

Yohimbine premedication and 35% CO2 vulnerability in healthy volunteers.

A group of 20 healthy volunteers underwent a 35% carbon dioxide/65% oxygen air-placebo controlled challenge test twice, premedicated 1 h before with either 20 mg yohimbine or placebo, following a double-blind randomized crossover design. Contrary to expectation the anxiety response to carbon dioxide was not higher when premedicated with yohimbine compared to premedication with placebo. Possible implications of this finding are discussed, with reference to general chemical models of panic.

Adolescent↗