Association of dysfunctional breathing with health-related quality of life: A cross-sectional study in a young population

Symptomatic hyperventilation (SH) is a pathological condition that manifests with breathlessness, dyspnea, light-headedness, anxiety, and paresthesia. However, little is known about the prevalence of SH and its association with health-related quality of life (HRQoL) in a young population. The Nijmegen questionnaire (NQ), which measures severity of SH, had not previously been cross-culturally translated into Korean. In this study, the NQ was cross-culturally translated into Korean (KNQ), using translation and back-translation methods. To examine the reliability and validity levels of the KNQ, as well as its association with HRQoL, 237 college students (21.38 ± 2.45 years) were asked to complete the KNQ, the Korean version of the general health questionnaire (K-GHQ-30) and the short form-36 (K-SF-36). The KNQ showed satisfactory reliability (Cronbach's α = 0.878). In the construct validity test, four factors (neuropsychological, respiratory, neurogastrointestinal, and neuromuscular) were extracted (% of total variance = 59.8). Using a KNQ cut-off score of 23 points, the prevalence of SH was 22.8%. Physical and mental HRQoL levels estimated by the K-GHQ-30 score and the 8 subscale scores of the K-SF-36 were lower in the SH group than in those of the non-SH group. It is concluded that the cross-culturally translated KNQ is reliable and valid, and management of SH may prevent a reduction in physical and mental HRQoL in a young population.

Role of the Nurse Counsellor in Managing Patients with the Hyperventilation Syndrome

A hyperventilation clinic was established specifically to deal with patients referred from the accident and emergency department with the hyperventilation syndrome. This was run by a staff nurse, who counselled the patients and taught abdominal breathing techniques and relaxation. In 30 patients so managed, 63% said their symptoms were much better or had completely gone and in only 6% was there no improvement; 43% had previously had more than one attendance at the A&E department, but following treatment only 2 patients represented during 5 months of follow up. The use of a nurse counsellor seems to be a simple and effective approach to managing these patients and considerably reduces both casualty and outpatient physician time.

Pitt-Hopkins Syndrome: A Review of Current Literature, Clinical Approach, and 23-Patient Case Series

Pitt-Hopkins syndrome (PTHS) is a rare, genetic disorder caused by a molecular variant of TCF4 which is involved in embryologic neuronal differentiation. PTHS is characterized by syndromic facies, psychomotor delay, and intellectual disability. Other associated features include early-onset myopia, seizures, constipation, and hyperventilation-apneic spells. Many also meet criteria for autism spectrum disorder. Here the authors present a series of 23 PTHS patients with molecularly confirmed TCF4 variants and describe 3 unique individuals. The first carries a small deletion but does not exhibit the typical facial features nor the typical pattern of developmental delay. The second exhibits typical facial features, but has attained more advanced motor and verbal skills than other reported cases to date. The third displays typical features of PTHS, however inherited a large chromosomal duplication involving TCF4 from his unaffected father with somatic mosaicism. To the authors' knowledge, this is the first chromosomal duplication case reported to date.

Failure of Perception of Hypocapnia: Physiological and Clinical Implications

Hyperventilation causes hypocapnia and respiratory alkalosis and thereby predisposes to coronary vasoconstriction and cardiac arrhythmia. Diagnostic methods for use between episodes have not been established.

In this study of 100 patients and 25 control subjects the resting end-tidal PCO2 (Pet CO2) levels and the results of a forced hyperventilation test did not show a significant difference between the groups. However the patients hyperventilated more profoundly in response to emotional stimulation, and were less aware of inappropriate breathing and hypocapnia.

It is suggested that these differences should be accommodated in cardiac rehabilitation.

Is Chronic Fatigue Syndrome Synonymous with Effort Syndrome?

Chronic fatigue syndrome (CFS), including myalgic encephalomyelitis (ME) and postviral syndrome (PVS), is a term used today to describe a condition of incapacity for making and sustaining effort, associated with a wide range of symptoms. None of the reviews of CFS has provided a proper consideration of the effort syndrome caused by chronic habitual hyperventilation. In 100 consecutive patients, whose CFS had been attributed to ME or PVS, the time course of their illness and the respiratory psychophysiological studies were characteristic of chronic habitual hyperventilation in 93. It is suggested that the labels ‘CFS’, ‘ME’ or TVS' should be withheld until chronic habitual hyperventilation - for which conventional rehabilitation is available - has been definitively excluded.

Blood-Injection-Injury (B-I-I) Specific Phobia Affects the Outcome of Hypoxic Challenge Testing

BACKGROUND

Blood-injection-injury (B-I-I) phobia is capable of producing inaccurate hypoxic challenge testing results due to anxiety-induced hyperventilation.

CASE REPORT

A 69-yr-old woman with a history of hypersensitivity pneumonitis, restrictive spirometry, exercise desaturation requiring supplementary oxygen on mobilizing, reduced DLco, and B-I-I phobia was referred for hypoxic challenge testing (HCT) to assess in-flight oxygen requirements. HCT was performed by breathing a 15% FIo2 gas mixture, simulating the available oxygen in ambient air onboard aircraft pressurized to an equivalent altitude of 8000 ft. Spo2 fell to a nadir value of 81% during HCT, although it rapidly increased to 89% during the first of two attempts at blood gas sampling. A resultant blood gas sample showed an acceptable Po2 outside the criteria for recommending in-flight oxygen and a reduced Pco2. Entering the nadir Spo2 value into the Severinghaus equation gives an estimated arterial Po2 of 6 kPa (45 mmHg), which was felt to be more representative of resting values during HCT, and in-flight oxygen was recommended.

DISCUSSION

While hyperventilation is an expected response to hypoxia, transient rises in Spo2 coinciding with threat of injury are likely to be attributable to emotional stress-induced hyperventilation, characteristic of B-I-I specific phobia and expected during the anticipation of exteroceptive threat, even in normal subjects. In summary, should excessive hyperventilation be detected during HCT and coincide with transient increases in Spo2, HCT should be repeated using Spo2 only as a guide to the level of hypoxemia, and Spo2 maintained using supplementary oxygen in accordance with alternative methods described in guidelines.Spurling KJ, McGoldrick VP. Blood-injection-injury (B-I-I) specific phobia affects the outcome of hypoxic challenge testing. Aerosp Med Hum Perform. 2017; 88(5):503-506.

Fatal and nonfatal drowning outcomes related to dangerous underwater breath-holding behaviors - New York State, 1988-2011

Drowning is an important cause of preventable injury and mortality, ranking fifth among leading causes of unintentional injury death in the United States. In 2011, two healthy young men died in a drowning incident at a New York City (NYC)-regulated swimming facility. The men became unconscious underwater after performing intentional hyperventilation before submersion. The phenomenon of healthy swimmers becoming unconscious underwater has been described elsewhere as hypoxic blackout. Prompted by this incident, the NYC Department of Health and Mental Hygiene (DOHMH) in collaboration with the New York State Department of Health (SDOH) conducted a case review of New York state fatal and nonfatal drownings reported during 1988-2011 to investigate similar behaviors in other incidents. DOHMH identified 16 cases, three in NYC, with a consistent set of voluntary behaviors associated with unintentional drowning and designated this class of behaviors as "dangerous underwater breath-holding behaviors" (DUBBs). For this small sample, the frequency of different DUBBs varied by age and swimming level, and practicing more than one DUBB increased the risk for fatality. This research contributes to the literature on drowning by focusing on contributing behaviors rather than drowning outcomes. NYC recently enacted public health education and regulations that discourage DUBBs; these interventions have the potential to effectively reduce unintentional drowning related to these behaviors and could be considered by other municipalities and jurisdictions.

Functional somatic syndromes: asking about exclusionary medical conditions results in decreased prevalence and overlap rates

BACKGROUND

The diagnosis of functional somatic syndromes (FSS) requires 1) presence of somatic symptoms, and 2) absence of medical conditions potentially accounting for these symptoms. Due to the limited feasibility of medical examinations, epidemiological research on FSS has neglected to assess the second criterion. Our objective was therefore to evaluate the implications of considering information on exclusionary medical conditions in epidemiological research on FSS.

METHODS

A survey among 3'054 students was conducted. We compared prevalence rates and overlap of 17 FSS obtained by: 1) a symptom-based strategy and 2) a symptom-and-exclusion-based strategy including information on exclusionary medical conditions.

RESULTS

The symptom-and-exclusion-based strategy led to a marked decrease in prevalence rates compared to the symptom-based strategy. Furthermore, it resulted in fewer individuals who were affected by multiple FSS.

CONCLUSIONS

Adding self-reported information on exclusionary medical conditions leads to a significant decrease in the prevalence and overlap of FSS. More rigorous approaches to studying FSS should be adopted.

Cardiovascular activity in blood-injection-injury phobia during exposure: evidence for diphasic response patterns?

Exposure to feared stimuli in blood-injection-injury (BII)-phobia is thought to elicit a diphasic response pattern, with an initial fight-flight-like cardiovascular activation followed by a marked deactivation and possible fainting (vasovagal syncope). However, studies have remained equivocal on the importance of such patterns. We therefore sought to determine the prevalence and clinical relevance of diphasic responses using criteria that require a true diphasic response to exceed cardiovascular activation of an emotional episode of a negative valence and to exceed deactivation of an emotionally neutral episode. Sixty BII-phobia participants and 20 healthy controls were exposed to surgery, anger and neutral films while measuring heart rate, blood pressure, respiratory pattern, and end-tidal partial pressure of carbon dioxide (as indicator of hyperventilation). Diphasic response patterns were observed in up to 20% of BII-phobia participants and 26.6% of healthy controls for individual cardiovascular parameters. BII-phobia participants with diphasic patterns across multiple parameters showed more fear of injections and blood draws, reported the strongest physical symptoms during the surgery film, and showed the strongest tendency to hyperventilate. Thus, although only a minority of individuals with BII phobia shows diphasic responses, their occurrence indicates significant distress. Respiratory training may add to the treatment of BII phobia patients that show diphasic response patterns.

Alcohol use history and panic-relevant responding among adolescents: a test using a voluntary hyperventilation challenge

Given the onset of alcohol use, neurological sensitivity, and enhanced panic-relevant vulnerability, adolescence is a key period in which to study the documented linkage between alcohol and panic-related problems. The current study was designed to build upon and uniquely extend extant work via (a) utilization of well-established experimental psychopathology techniques and (b) evaluation of unique associations between alcohol use and panic symptoms after controlling for theoretically relevant behavioral, environmental, and individual difference variables (i.e., age, gender, negative affectivity, anxiety sensitivity, child and parent tobacco use, and parental panic disorder). Participants were 111 community-recruited adolescents ages 12-17 years (M = 15.76 years; n = 50 girls). Youth completed a battery of well-established questionnaires and a voluntary hyperventilation challenge, and parents present at the laboratory completed a structured clinical interview. Adolescent alcohol use was categorized as Non-Users, Experimenters, or Users. Panic symptoms were indexed via retrospective self-report and adolescents' response to a biological challenge procedure (i.e., voluntary hyperventilation). After controlling for theoretically relevant covariates, Users evidenced elevated panic-relevant symptoms and responding compared with Non-Users; Experimenters did not differ from Non-Users. Findings suggest alcohol use history is uniquely associated with panic symptomatology among youth, including "real-time" reactivity elicited by a laboratory challenge. Although there is significant work yet to be done, these data advance extant work and lay the groundwork for the types of sophisticated designs that will be needed to answer the most pressing and complex questions regarding the link between alcohol use and panic symptoms among adolescents.

[Hyperventilation syndrome and bronchial asthma: role of verbal dyspnea characteristics in differential diagnosis]

AIM

To investigate verbal dyspnea characteristics in patients with bronchial asthma (BA) and hyperventilation syndrome (HVS).

MATERIAL AND METHODS

The trial covered 52 patients with BA, 10 patients with BA combination with HVS and 18 patients with HVS. Verbal dyspnea characteristics were studied with PM. Simon questionnaire. The examination of the patients was made using scale HADS. Naimigen questionnaire, body plethysmography, bronchodilation test, capnography with spontaneous hyperventilation test, analysis of arterial blood gas composition.

RESULTS

Most commonly BA patients characterized dyspnea with such words as "I am breathless" (n = 8, 33.3%), "I breathe with effort" (n = 6, 25%) and "I feel suffocation" (n = 6, 25%). HVS patients characterized their dyspnea most often as "air shortage" (n = 14, 77.8%), "I can't take a deep breath" (n = 10, 55.6%), "breathing needs concentration" (n = 6, 33.3%) and "I have to grasp air with mouth" (n = 5, 17.9%). The latter description correlated with capnometric markers of HVS and responses to Naimigen questionnaire. The description "I feel suffocation" directly correlated with BA stage by GINA and bronchial obstruction severity.

CONCLUSION

Verbal dyspnea characteristics differ in BA and HVS patients and this can be used in differential diagnosis of these conditions.

[Device diagnosis and combined treatment of hyperventilation syndrome]

Hyperventilation syndrome is a separate disease and a symptom of other psychosomatic diseases. A variant of device diagnosis of the disease is proposed--integral rheoplethysmography by M. I. Tischenko and cardiointervalography by R. M. Baevsky. Hyper- and asthenic courses of the disease are described, the pathological psychoemotional pattern is recognized. The proposed treatment combines physiohemotherapy (laser treatment) and pharmacotherapy.

An examination of the relation between traumatic event exposure and panic-relevant biological challenge responding among adolescents

The current study uniquely extended research that has linked traumatic event exposure to panic-spectrum problems among adolescents. It was hypothesized that among 127 adolescents (age range: 10 to 17 years; M = 14.63, SD = 2.24), those who endorsed a history of traumatic event exposure would evidence significantly greater anxious and fearful reactivity to a well-established 3-min voluntary hyperventilation procedure compared to nonexposed individuals. Results were consistent with hypotheses, suggesting traumatic event exposure is associated with anxious and fearful reactivity to abrupt increases in bodily arousal among adolescents. Moreover, consistent with hypotheses, anxiety sensitivity significantly mediated the relations between traumatic event exposure and both self-reported panic symptoms and panic symptoms elicited by the challenge. Future prospective research is now needed to better understand temporal relations between traumatic event exposure and indices of panic and related vulnerability.

[Hyperventilation syndrome]

Hyperventilation syndrome is a disorder affecting children and adults, mostly women. It is frequently associated with anxiety disorders, and greatly affects quality of life. Diagnosis, which unfortunately is most often established late, is a diagnosis of elimination. It rests on a wide range of non-specific signs, on Nijmegën's clinical scale as well as on a hyperventilation provocative test. In most cases, specialized therapeutic interventions allow for an adequate control of ventilation and symptom relief.

The interactive effect of anxiety sensitivity and frequency of marijuana use in terms of anxious responding to bodily sensations among youth

Marijuana use is associated with anxiety, particularly among those anxiety conditions in which panic is common. It may therefore be that risk factors for panic increase the likelihood that marijuana users will experience problematic anxiety symptoms. The current study investigated the role of one such risk factor, anxiety sensitivity (AS), or the extent to which an individual is frightened of anxiety symptoms. We examined whether AS interacts with frequency of marijuana use to increase anxious responding (using a three-minute voluntary hyperventilation procedure). The sample consisted of 153 adolescents (46.4% female) ages 11-17 (M=14.92, S.D.=1.49). As predicted, AS moderated the link between lifetime marijuana use frequency and both post-challenge physiological anxiety (as indexed by skin conductance) and post-challenge subjective anxiety in female (but not male) adolescents such that those with high AS and more frequent marijuana use demonstrated the highest level of challenge-induced fear response. This effect remained even after controlling for relevant variables (e.g., age, trait anxiety, lifetime alcohol and cigarette use). Present findings suggest AS appears to serve as an important and potentially specific anxiety-related variable that deserves serious attention as a potential vulnerability factor among frequent marijuana-using females.

Respiratory irregularity and stress hormones in panic disorder: exploring potential linkages

Dysregulation within both respiratory control systems and the hypothalamic-pituitary adrenal (HPA) axis has been implicated in the pathophysiological of panic disorder. However, potential linkages between respiration and the HPA axis have rarely been examined in panic patients. We have previously published neuroendocrine and psychophysiological response data from a laboratory panic model using the respiratory stimulant doxapram. We now present a new, theoretically driven re-examination of linkages between HPA axis and respiratory measures in this model. Previous analyses showed elevated corticotropin (ACTH) and persistent tidal volume irregularity in panic patients, due to a high frequency of sighs. Regression analyses now show that tidal volume irregularity and sigh frequency were strongly predicted by pre-challenge ACTH levels, but not by subjective distress or panic symptoms. We predicted this relationship on the basis of our hypothesis that both the HPA axis and respiratory control systems may be reactive to contextual cues such as novelty or anticipation of future challenge. Follow-up work is needed to directly test this hypothesis.

[The hyperventilation syndrome]

The hyperventilation syndrome is a disease affecting children as well as adults. It predominates in female and may be debilitating. It is frequently associated with anxiety. The diagnosis, that is unfortunately often belated, is a diagnosis of exclusion and relies on the anamnesis, various non specific signs, on the Nijmegens score and on a hyperventilation provocation test. A specialized treatment allows, in most cases, a good control of ventilation and the disappearance of symptoms.

Biological challenge procedures used to study co-occurring nicotine dependence and panic disorder

A wide array of biological challenge procedures - including carbon dioxide inhalation, hyperventilation, and breath holding - have been used to model panic in laboratory settings. Originally used to study developmental processes in panic disorder (PD), these procedures, along with nicotine patch administration and self-administered smoking, have recently been applied to help understand the etiology of co-occurring nicotine dependence and PD. The goals of the present paper are to review studies that have employed biological challenges to study the comorbid condition, identify the advantages and limitations of the various procedures, describe desirable outcome measures for use in biological challenges, and present recommendations for future challenge studies in this field. We argue that biological challenges, though in need of standardization, are useful for studying the development, maintenance, prevention, and treatment of comorbid nicotine dependence and PD.

Panic reactivity to voluntary hyperventilation challenge predicts distress tolerance to bodily sensations among daily cigarette smokers

The present investigation examined the extent to which panic reactivity to bodily sensations is related to distress tolerance (DT) among daily smokers. It was hypothesized that panic reactivity to an initial voluntary hyperventilation (i.e., whether participants met criteria for a DSM-IV panic attack; PA) would predict the relative degree of task persistence on a second hyperventilation trial (DT) above and beyond the variance accounted for by anxiety sensitivity (AS), negative affectivity (NA), cigarette smoking rate, and self-reported discomfort intolerance (DI). Participants were 95 daily smokers (58% women; M-sub(age) = 29.0, SD = 12.2) who completed a battery of questionnaires and two voluntary hyperventilation procedures. Results indicated PA status significantly predicted DT, above and beyond the theoretically relevant covariates of AS, NA, cigarettes per day, and DI ( p < .05). Such a result is consistent with theoretical models and empirical findings on emotional reactivity that suggest panic responsivity to internal cues may represent a key explanatory construct in terms of level of DT to interoceptive stimuli.

Psychophysiological reactions to two levels of voluntary hyperventilation in panic disorder

Panic disorder (PD) patients usually react with more self-reported distress to voluntary hyperventilation (HV) than do comparison groups. Less consistently PD patients manifest physiological differences such as more irregular breathing and slower normalization of lowered end-tidal pCO(2) after HV. To test whether physiological differences before, during, or after HV would be more evident after more intense HV, we designed a study in which 16 PD patients and 16 non-anxious controls hyperventilated for 3 min to 25 mmHg, and another 19 PD patients and another 17 controls to 20 mmHg. Patients reacted to HV to 20 mmHg but not to 25 mmHg with more self-reported symptoms than controls. However, at neither HV intensity were previous findings of irregular breathing and slow normalization of pCO(2) replicated. In general, differences between patients and controls in response to HV were in the cognitive-language rather than in the physiological realm.

Panic disorder subtypes: further clinical differences

Panic disorder (PD) is a heterogeneous phenomenon with respect to symptom profile. Most studies agree that a group of patients with prominent respiratory symptoms emerged as a distinct PD subtype. In this study we compared a range of clinical features associated with PD and agoraphobia in patients with respiratory (RS) and nonrespiratory (NRS) subtypes of PD. The participants were 124 patients with PD (79 women and 45 men), with or without agoraphobia, diagnosed by DSM-IV criteria. Following the observer-rated Panic Disorder Severity Scale assessment, subjects completed self-report measures, including the Anxiety Sensitivity Index (ASI), Panic-Agoraphobia Scale; the Beck Anxiety Inventory; and the Panic-Agoraphobic Spectrum Scale (PAS-SR). Multivariate analysis of variance (MANOVA) showed significant group differences [Pillai's trace = 0.95, F (5, 118)(=)2.48, P = .036]. Patients in RS group had higher mean total scores on the ASI (F = 5.00, df = 1, P = .027) and PAS-SR (F = 11.23, df = 1, P = .001) than patients in NRS group. Also, patients with RS attained higher scores than patients with NRS on four domains of PAS-SR (panic-like symptoms, agoraphobia, separation sensitivity, and reassurance seeking). A descriptive discriminant analysis of the data correctly identified 69.4% of the patient group in general and 86.1% of RS group (Wilks's lambda = 0.87, df = 8, P = .048). The significant discriminating factors of the RS and NRS groups were domains of panic-like symptoms, agoraphobia, separation sensitivity, and reassurance seeking. Our findings suggest that anxiety sensitivity and panic-agoraphobic spectrum symptoms might be particularly relevant to understanding subtypes of PD.

The effect of cognitive load and hyperarousal on negative intrusive memories

Clinical theories of post-traumatic stress suggest that encoding processes at the time of a trauma are critical in determining whether intrusive memories will develop. Potential mechanisms that might influence the development of intrusive memories were studied, as was objective memory performance. In an analogue design, 65 participants were randomised to three conditions (cognitive load, hyperventilation, and control), and then watched a film of traumatic content. Intrusive memories were recorded during the experimental phase and at 1-week follow-up. Support was found for the prediction that verbal cognitive load and hyperventilation would facilitate intrusion development immediately following exposure to the trauma film; however, this was not maintained at follow-up. Consistent with cognitive models of post-traumatic stress, thought suppression and the distress associated with intrusive experiences mediated the relationship between distress caused by the film and intrusions at 1-week follow-up. Objective memory testing indicated that the three experimental groups showed similar recall and recognition performance for the content of the film; however, relative to the control group, individuals in the cognitive load condition were significantly less able to place film scenes in the correct order.

Hyperventilation in patients with chronic fatigue syndrome: the role of coping strategies

Hyperventilation has been suggested as a concomitant and possible maintaining factor that may contribute to the symptom pattern of chronic fatigue syndrome (CFS). Because patients accepting the illness and trying to live with it seem to have a better prognosis than patients chronically fighting it, we investigated breathing behavior during different coping response sets towards the illness in patients with CFS (N=30, CDC criteria). Patients imagined a relaxation script (baseline), a script describing a coping response of hostile resistance, and a script depicting acceptance of the illness and its (future) consequences. During each imagery trial, end-tidal PCO2 (Handheld Capnograph, Oridion) was measured. After each trial, patients filled out a symptom checklist. Results showed low resting values of PetCO2 overall, while only imagery of hostile resistance triggered a decrease and deficient recovery of PetCO2. Also, more hyperventilation complaints and complaints of other origin were reported during hostile resistance imagery compared with acceptance and relaxation. In conclusion, hostile resistance seems to trigger both physiological and symptom perception processes contributing to the clinical picture of CFS.

The role of hyperventilation: hypocapnia in the pathomechanism of panic disorder

OBJECTIVE: The authors present a profile of panic disorder based on and generalized from the effects of acute and chronic hyperventilation that are characteristic of the respiratory panic disorder subtype. The review presented attempts to integrate three premises: hyperventilation is a physiological response to hypercapnia; hyperventilation can induce panic attacks; chronic hyperventilation is a protective mechanism against panic attacks. METHOD: A selective review of the literature was made using the Medline database. Reports of the interrelationships among panic disorder, hyperventilation, acidosis, and alkalosis, as well as catecholamine release and sensitivity, were selected. The findings were structured into an integrated model. DISCUSSION: The panic attacks experienced by individuals with panic disorder develop on the basis of metabolic acidosis, which is a compensatory response to chronic hyperventilation. The attacks are triggered by a sudden increase in (pCO2) when the latent (metabolic) acidosis manifests as hypercapnic acidosis. The acidotic condition induces catecholamine release. Sympathicotonia cannot arise during the hypercapnic phase, since low pH decreases catecholamine sensitivity. Catecholamines can provoke panic when hyperventilation causes the hypercapnia to switch to hypocapnic alkalosis (overcompensation) and catecholamine sensitivity begins to increase. CONCLUSION: Therapeutic approaches should address long-term regulation of the respiratory pattern and elimination of metabolic acidosis.

Carbon dioxide provocation of anxiety and respiratory response in bipolar disorder

BACKGROUND

Frequent bipolar/panic comorbidity implies bipolar individuals may experience CO2-provoked anxiety and changes in respiratory patterns similar to those experienced by individuals with panic disorder.

METHODS

16 euthymic bipolar individuals breathed air and air combined with 5% CO2 for 15 min each. Respiratory and subjective anxiety measures were collected.

RESULTS

On CO2 subjects were more anxious and breathed more deeply and rapidly than with air; the degree of increase in anxiety attributable to CO2 was directly correlated with the degree of increase in minute ventilation. Five individuals were assessed as having a panic attack. Panic response to CO2 was predicted by the degree of anxiety experienced with air alone.

CONCLUSIONS

Comparison with the results of similar panic studies shows bipolar disorder is associated with enhanced respiratory response to CO2. Hypersensitivity to CO2 among bipolar individuals suggests a possible pathological mechanism common to both bipolar and panic disorders. These preliminary data support the expanded application of CO2 challenges in bipolar subjects.

Evidence for respiratory and nonrespiratory subtypes in panic disorder

Recently researchers have posited a "respiratory" subtype of panic disorder (PD), which differs from "nonrespiratory" subtypes in phenomenology and perhaps treatment response. This study was designed to further examine evidence for the existence of a respiratory subtype in PD. Individuals with PD with prominent respiratory symptoms (PD-R; n=10) and without prominent respiratory symptoms (PD-NR; n=23), as well as healthy controls (n=27), underwent a standardized 5% CO(2) rebreathing challenge. Ventilatory response and subjective sensation of suffocation were continuously recorded. The PD-R group exhibited greater subjective suffocation levels, rates of respiration, and propensity to terminate the procedure voluntarily than did the other two groups, which in turn did not differ on these measures. Findings are consistent with the existence of a respiratory subtype of PD, which differs from nonrespiratory subtypes in CO(2) sensitivity.

Pubertal status and emotional reactivity to a voluntary hyperventilation challenge predicting panic symptoms and somatic complaints: a laboratory-based multi-informant test

The main and interactive effects of pubertal status and emotional reactivity to bodily sensations elicited by a voluntary hyperventilation challenge were examined in relation to panic symptoms and self- and parent-reported somatic complaints among 123 (56 females) adolescents between the ages of 12 and 17 years (M(age) = 15.05; SD = 1.50). As expected, after controlling for baseline anxiety, age, and gender, there was a significant interaction between pubertal status and challenge response in predicting the outcome variables. Specifically, adolescents reporting more advanced pubertal status and greater reactivity to the challenge evidenced greater levels of panic symptoms and somatic complaints, whereas pubertal status had relatively less of an effect on these variables among adolescents who did not respond as fearfully to the challenge. Results are discussed in terms of extant theory and research on anxiety vulnerability among adolescents.

US-inflation in a differential odor-conditioning paradigm is not robust: relevance for medically unexplained symptoms

Reported somatic symptoms without clear relation to physiological processes are studied. A learning paradigm was used with two odors (CSs) and the inhalation of CO(2)-enriched air (US), while measuring symptom levels and respiratory behavior. After paring one odor with the CO(2)-enriched air and the other odor with air, half of the participants received a US-inflation manipulation (information manipulation and enhanced US). Subsequently, all participants received both odors with air (test). A difference between the odor previously paired with CO(2)-enriched air and the odor previously paired with air was found for the symptom measure, US-expectancy ratings, and, to a lesser extent, for respiratory volume. No differences, however, were found between the group receiving the US-inflation manipulation and a group not receiving this manipulation. The results indicate that, despite a successful learning of reported symptoms, US-inflation does not seem to be robust.

Affect intensity: association with anxious and fearful responding to bodily sensations

The present investigation evaluated affect intensity in regard to anxious and fearful responding to a voluntary hyperventilation paradigm. Participants were 90 young adults without a history of Axis I psychopathology or nonclinical panic attacks. The incremental validity of affect intensity was examined relative to gender, negative affectivity, anxiety sensitivity, and anticipatory anxiety. As hypothesized, affect intensity significantly and incrementally predicted the perceived intensity of post-challenge panic-relevant physical and cognitive symptoms but not physiological arousal. Findings are discussed in relation to better understanding the role of affect intensity as a potential risk factor for panic-related problems.

Cyanotic episodes in a male child with fragile X syndrome

A 9-year-old male with a diagnosis of fragile X syndrome (FXS) was evaluated for cyanotic episodes of unknown etiology. Clinical observation revealed frequent episodes of hyperventilation lasting several minutes, only while the patient was awake. This was followed by apnea associated with cyanosis and oxygen desaturation. Polysomnogram confirmed episodic central apnea temporally associated with hypocapnia, only during the awake state. Extensive evaluation failed to reveal other neurological, cardiac, gastrointestinal, or pulmonary etiologies for the events. The clinical observations and investigations allowed us to conclude that the patient's cyanotic episodes were caused by primary behavioral hyperventilation in the awake state. Similar behaviors have been reported in children with a variety of diagnoses but to our knowledge have not been previously reported in children with FXS. Treatment for this unusual behavior in FXS consists of reassurance and behavior modification to decrease the frequency and severity of the cyanotic episodes.

Comparison between hyperventilation and breath-holding in panic disorder: patients responsive and non-responsive to both tests

Our aim was to compare the demographic and psychopathological features of panic disorder (PD) patients who underwent hyperventilation and breath-holding challenge tests, and to describe the features of patients who had a panic attack after both tests versus those patients who did not experience panic after either test. Eighty-five PD patients were induced to hyperventilate (30 breaths/min) for 4 min, and a week later to hold their breath for as long as possible four times with a 2-min interval in between. Anxiety scales were applied before and after the tests. Patients who responded with a panic attack to both tests (BPA, n = 25) were compared with patients who experienced spontaneous panic attacks but did not panic in response to the two tests (NPA, n = 16). The BPA group had a significantly higher presence of respiratory symptoms during a panic attack. The criteria for the respiratory PD subtype were fulfilled in 18 (72.0%) BPA patients and in 6 (37.5%) NPA patients. The BPA patients had a later onset of panic disorder and a higher familial prevalence of PD. Our data suggest that there is a distinction between PD patients who were sensitive to both hyperventilation and breath-holding tests and PD patients who were not affected by the challenge tests. The panic attack may be a final common pathway for different types of stimuli, and respiratory tests may characterize different PD subgroups.

An examination of worry in relation to anxious responding to voluntary hyperventilation among adolescents

This study examined the association between worry and fearful responding to a 3-min voluntary hyperventilation procedure. Participants were 160 adolescents (71 females) between the ages of 12 and 17 years (M=14.92 years). After accounting for the significant effects of state anxiety and anxiety sensitivity, results indicated that pre-challenge levels of worry indexed by the Penn State Worry Questionnaire-Child Version predicted post-challenge anxiety and intensity of panic symptoms. Results are discussed in terms of the role of worry in relation to panic-relevant emotional vulnerability among youth.

Breath-holding spells in somatoform disorder

Breath-holding spells (BHS) are commonly seen in childhood. However, there are no case reports of BHS occurring in adolescents or young adults. We report two young adult cases and discuss the pathogensis, both physically and psychologically. BHS occurred for 1-2 minutes after hyperventilation accompanied by cyanosis in both cases. Oxygen saturation was markedly decreased. Each patient had shown distress and a regressed state psychologically. These cyanotic BHS occurred after hyperventilation, and we considered that a complex interplay of hyperventilation followed by expiratory apnea increased intrathoracic pressure and respiratory spasm. Breath-holding spells can occur beyond childhood.

Differential sensitivity of the three ASI factors in predicting panic disorder patients' subjective and behavioral response to hyperventilation challenge

The overall aim of the present investigation was to examine the association between the subscales of the ASI and emotional responding to voluntary hyperventilation challenge in a panic disorder population. Based on findings from [J. Abnorm. Psychol. 110 (2001) 372.], we predicted that the AS-Physical Concerns subscale would best predict the fear response to hyperventilation. We also examined the relative contribution of each of the three ASI subscales in predicting behavioral tolerance to hyperventilation. Participants (N = 192) meeting DSM-IV criteria for panic disorder with or without agoraphobia completed the Anxiety Sensitivity Index (ASI) and underwent a voluntary hyperventilation challenge. Consistent with prediction, the AS-Physical subscale significantly predicted subjective fear during the hyperventilation challenge (12% of variance accounted for); whereas only the AS-Social subscale accounted for significant variance (4%) in patients' behavioral tolerance to the hyperventilation challenge.

Clinical features of panic patients sensitive to hyperventilation or breath-holding methods for inducing panic attacks

Our aim was to compare the clinical features of panic disorder (PD) patients sensitive to hyperventilation or breath-holding methods of inducing panic attacks. Eighty-five PD patients were submitted to both a hyperventilation challenge test and a breath-holding test. They were asked to hyperventilate (30 breaths/min) for 4 min and a week later to hold their breath for as long as possible, four times with a 2-min interval. Anxiety scales were applied before and after the tests. We selected the patients who responded with a panic attack to just one of the tests, i.e., those who had a panic attack after hyperventilating (HPA, N = 24, 16 females, 8 males, mean age +/- SD = 38.5 +/- 12.7 years) and those who had a panic attack after breath holding (BHPA, N = 20, 11 females, 9 males, mean age +/- SD = 42.1 +/- 10.6 years). Both groups had similar (chi(2) = 1.28, d.f. = 1, P = 0.672) respiratory symptoms (fear of dying, chest/pain discomfort, shortness of breath, paresthesias, and feelings of choking) during a panic attack. The criteria of Briggs et al. [British Journal of Psychiatry, 1993; 163: 201-209] for respiratory PD subtype were fulfilled by 18 (75.0%) HPA patients and by 14 (70.0%) BHPA patients. The HPA group had a later onset of the disease compared to BHPA patients (37.9 +/- 11.0 vs 21.3 +/- 12.9 years old, Mann-Whitney, P < 0.001), and had a higher family prevalence of PD (70.8 vs 25.0%, chi(2) = 19.65, d.f. = 1, P = 0.041). Our data suggest that these two groups--HPA and BHPA patients--may be specific subtypes of PD.