Hyperventilation and panic attacks

The role of hyperventilation in the aetiology of panic attacks is still unclear. This paper briefly reviews the role of hyperventilation and abnormal respiration to panic attacks and examines the experimental evidence. Evidence has been found that physiological variables such as paCO2 and pH are involved in the aetiology of panic attacks and panic disorder but the extent and the nature of the involvement of cognitive variables is undetermined. Based on current evidence, there is a need to integrate cognitive variables with the physiological framework proposed by the hyperventilation theory. Until clear experimental evidence is produced about the relationships between cognitive and physiological factors, the applicability of hyperventilation in the aetiology and treatment of panic attacks remains in question.     

Hypoglycemia and panic attacks

Many patients with panic disorder believe hypoglycemia causes their symptoms. Of 10 patients with panic disorder given sodium lactate to induce panic, none had evidence of low blood sugar levels when they began to experience anxiety symptoms.     

Sertraline-induced panic attacks

Sertraline is a selective serotonin reuptake inhibitor that is approved by the U.S. Food and Drug Administration for the treatment of major depression, obsessive-compulsive disorder (in adults and children), and panic disorder. Although numerous studies have found sertraline to be very effective in the treatment of anxiety, there have been few case reports of panic attacks actually being induced by treatment with sertraline. In this article, we present the cases of two patients without any personal or family history of anxiety disorders who developed panic attacks shortly after the initiation of sertraline therapy. We will also review the literature in regard to the development of anxiety symptoms during treatment with the newer antidepressants and discuss the neurochemical basis of these antidepressant-induced panic attacks.     

Hyperventilation and panic attacks

The symptoms of hyperventilation syndrome and panic disorder are very similar. A questionnaire was used to assess the incidence of panic disorder in 274 patients; 35% of the patients with hyperventilation and only 5% of the non-hyperventilating patients showed panic disorder. The authors conclude that hyperventilation plays an important role in panic disorder and in generalized anxiety disorder.     

Duloxetine-related panic attacks

Side-effects arising on the grounds of antidepressant administration pose as a substantial obstacle hindering successful depressive disorder treatment. Side-effects, especially those severe or those manifested through dramatic clinical presentations such as panic attacks, make the treatment far more difficult and shake patients' trust in both the treatment and the treating physician. This case report deals with a patient experiencing a moderately severe depressive episode, who responded to duloxetine treatment administered in the initial dose of 30 mg per day with as many as three panic attacks in two days. Upon duloxetine withdrawal, these panic attacks ceased as well. The patient continued tianeptine and alprazolam treatment during which no significant side-effects had been seen, so that she gradually recovered. Some of the available literature sources have suggested the possibility of duloxetine administration to the end of generalised anxiety disorder and panic attack treatment. However, they are outnumbered by the contributions reporting about duloxetine-related anxiety, aggressiveness and panic attacks. In line with the foregoing, further monitoring of each and every duloxetine-administered patient group needs to be pursued so as to be able to evaluate treatment benefits and weigh them against risks of anxiety or panic attack onset.     

Nocturnal panic attacks

The panic-respiration connection has been presented with increasing evidences in the literature. We report three panic disorder patients with nocturnal panic attacks with prominent respiratory symptoms, the overlapping of the symptoms with the sleep apnea syndrome and a change of the diurnal panic attacks, from spontaneous to situational pattern. The implication of these findings and awareness to the distinct core of the nocturnal panic attacks symptoms may help to differentiate them from sleep disorders and the search for specific treatment.     

Modeling panic attacks

The isomorphism of dorsal periaqueductal gray-evoked defensive behaviors and panic attacks was appraised in the present study. Thresholds of electrically induced immobility, trotting, galloping, jumping, exophthalmus, micturition and defecation were recorded before and after acute injections of anxiolytic, anxiogenic and antidepressant drugs. Antidepressant effects were further assessed 24 h after injections of 7–14- and 21-day treatments. Chronic administration of clomipramine (CLM, 5–10 mg/kg) a clinically effective antipanic drug increased the thresholds of immobility (24%), trotting (138%) galloping (75%), jumping (45%) and micturition (85%). The 21-day treatment with fluoxetine (FLX, 1 mg/kg) virtually abolished galloping without changing the remaining responses. Galloping thresholds were also increased by 5 mg/kg acute injections of CLM (19%) and FLX (25%). In contrast, chronically administered maprotiline (10 mg/kg), a noradrenaline (NE) selective reuptake inhibitor, selectively increased the thresholds of immobility (118%). Diazepam (1.8 mg/kg) and midazolam (MDZ, 2.5 mg/kg) failed in attenuating the somatic defensive responses. Yet, the sedative dose of MDZ (5 mg/kg) attenuated immobility. The panicogenic drug, pentylenetetrazole (50 mg/kg), markedly decreased the thresholds of galloping (−51%) and micturition (−66%). These results suggest that whereas immobility is a NE-mediated attentional response, galloping is the panic-like behavior best candidate.     

Insulin-induced hypoglycemia and panic attacks

To investigate whether hypoglycemia might trigger panic attacks, the authors administered intravenous insulin to 10 patients with panic disorder. All subjects developed hypoglycemia but no panic anxiety. They reported symptoms of adrenergic hyperactivity but differentiated them from spontaneous panic attacks.     

Sleep apnea and panic attacks

A survey of 301 sleep apnea patients demonstrated that obstructive sleep apnea may cause nocturnal panic attack symptoms. Sleep apnea should be considered in the differential diagnosis of nocturnal panic disorder.     

Sleep disorders and panic attacks

The aim of this work is to describe the clinical and polisomnographical characteristics of patients suffering prevailing night panic attacks. The most usual therapeutics are also briefly mentioned. The Polisomnography and especially the EGG are mentioned as the methods which allow the most accurate diagnosis since the night panic attack produces patognomonical disturbances.     

Epinephrine-induced panic attacks and hyperventilation

To assess the effects of epinephrine on ventilation in patients with panic disorder and in social phobics, analyses were performed on pooled data from two previous infusion studies. Throughout the infusion, changes in transcutaneous PCO2 (tcPCO2), subjective anxiety, heart rate and blood pressure were recorded continuously. Twenty-nine patients received epinephrine, ten patients received placebo. Thirteen patients (45%) had a panic attack during epinephrine. The fall in tcPCO2 and the cardiovascular response was greater in panicking patients than patients who did not panic. Although the fall in tcPCO2 associated with panic was not substantial and did not indicate clinically significant acute hyperventilation, it appears to be a sensitive index for epinephrine-induced panic. The fall in tcPCO2 was predicted rather by the frequency of occurrence of anxiety-related somatic symptoms than by the fear of these symptoms. These findings further reduce a role for fear of bodily sensations in epinephrine-induced panic attacks and favor a biological sensitivity to sympathetic stimulation.     

Frequency of panic attacks and panic disorder in adolescents

By using data from the Bremer Adolescent Study, this report presents findings on the frequency, comorbidity, and psychosocial impairment of panic disorder and panic attacks among 1,035 adolescents. The adolescents were randomly selected from 36 schools in the province of Bremen, Germany. Panic disorder and other psychiatric disorders were coded based on DSM-IV criteria using the computerized-assisted personal interview of the Munich version of the Composite International Diagnostic Interview. Panic disorder occurred rather rare, with only 0.5% of all the adolescents met the DSM-IV criteria for this disorder sometimes in their live. Panic attack occurred more frequently, with 18% of the adolescents reported having had at least one panic attack. Slightly more girls than boys had panic attack and panic disorder. The occurrence of panic attack and panic disorder were the greatest among the 14–15 year olds. The experience of having a panic attack was associated with a number of problems, the most frequent being avoiding the situation for fear of having another attack. Four most common symptoms associated with a panic attack were that of palpitations, trembling/shaking, nausea or abdominal distress, and chills or hot flushes. Panic disorder comorbid highly with other psychiatric disorders covered in our study, especially with that of major depression. Among those with a panic disorder, about 40% of them were severely impaired during the worst episode of their illness. Only one out of five adolescents with panic disorder sought professional help for emotional and psychiatric problems. The implication of our findings for research and clinical practice are discussed. Depression and Anxiety 9:19–26, 1999. © 1999 Wiley-Liss, Inc.