What are Panic Attacks and Panic Disorder
In the United States, over 7M people annually suffer from panic disorder (PD), a condition in which the patient has recurrent, unpredictable panic attacks followed by persistent fears about repeat attacks. Panic attacks and fear of potential attacks can have a profound impact on quality of life – resulting in avoidance behaviors such as missing work, not going out with friends, avoiding public places or fear of leaving the house. Panic attacks are also a common component of other Anxiety Disorders (e.g., Post Traumatic Stress Disorder, Specific Phobias, Social Anxiety Disorder and Generalized Anxiety Disorder), and affect a total of 27M in the US per year. Women are 2-4 times more likely to suffer from PD than men and the most common age group for symptom onset is 25 – 44 years old. PD patients are more likely to commit suicide than depression patients [2,3] and over 25% of them abuse/misuse alcohol . PD patients also consume significantly more healthcare resources than non-PD patients with similar health profiles. A recent analysis conducted by a health economics firm demonstrated that compared with age, gender and health risk-factor matched controls, PD patients:
- Are 5.4 times more likely to have an any-cause emergency room visit,
- Have 3.4 times more physician office visits,
- Have 6 times higher pharmacy claims,
- Are 5.6 times more likely to develop additional mental health disorders or substance abuse.
[* Source: data on file].
Current, evidence-based standards of care to treat PD include Cognitive Behavioral Therapy (CBT) and treatment with benzodiazepines and antidepressants. Limitations of CBT include cost, limited availability of CBT-trained therapists (only 12% of PD patients receive a formal CBT program), high dropout rates and fear of interoceptive exposure. Medication limitations include side effects, especially of SSRI/SNRI, risk of abuse of benzodiazepine-class medications and relapse after discontinuation. Of note, 75% of patients say they do not want to take medications and 47% discontinue taking SSRI/SNRIs within 180 days (of these discontinuations, 84% are in the first 90 days). A recent study published in the Journal of Clinical Psychiatry, reported that when treated with anti-depressants, chronically depressed patients with co-morbid panic disorder experienced greatly increased frequency and intensity of cardiac, gastrointestinal, neurological and genitourinary side effects vs. patients without the co-morbid panic. In addition, the subjects with depression and co-morbid panic showed a greater risk of worsening depressive symptoms associated with multiple side effects. These limitations in treating panic with medication or CBT lead patients to continue misinterpreting their panic symptoms as serious medical events, driving increased emergency department and medical specialist visits.
Costs of Panic Disorder and Panic Attacks to Payers
Patients with panic attacks or panic disorder (PD) often misinterpret their panic symptoms of a racing heart, dizziness, sweating and nausea as a serious life threatening event such as a heart attack or stroke, prompting emergency room visits and multiple primary and specialist doctor visits. Once these individuals are correctly diagnosed with PD, they are typically treated with cognitive behavioral therapy (CBT) and/or prescription medications (typically anti-depressants). If locally available, CBT is burdensome for the patient (12-weeks of weekly sessions) with limited effectiveness. Medication use is frequently discontinued due to adverse side-effects. Adherence with both CBT and the typical medications is poor and the costs of these treatments can be substantial.
A recent analysis conducted by a health economics firm reported that compared with age, gender and health risk-factor matched controls, PD patients:
- Incur an average of $5,300 more expense than matched healthy individuals
- Are 5.4 times more likely to have an any-cause Emergency Room visit
- Are 5.3 times more likely to have an Emergency Room visit related to panic symptoms or other psychiatric diagnosis
- Incur 3.4 times more Professional claims and 6 times more Pharmacy claims
- Over three years, are 5.6 times more likely to develop an additional Mental Health/Substance Abuse Disorder
* Health Lumen Data Analytic Project, 2016, commissioned by PAHS
Physiology of Respiration and Panic Attack
More than 30 years of research has demonstrated that abnormal respiratory function is almost universal in PD patients [4-9]. PD patients chronically hyperventilate and/or exhibit other dysfunctional respiratory patterns leading to lower than normal exhaled carbon dioxide (CO2) levels. While significant efforts at studying the role and relationship between abnormal respiration and panic disorder began in earnest in the 1980’s and 90’s, earlier work in the 1940’s by Finesinger identified abnormal sighing frequency in anxiety disorder subjects . Elements of the respiratory pattern that have been studied in PD patients include: respiratory rate, CO2 levels in blood via venous and arterial blood gas sampling (pCO2) and exhaled CO2 readings (EtCO2), minute ventilation, tidal volume and sighing frequency.
Panic attacks are often accompanied by severe respiratory distress (shortness of breath), rapid or irregular heartbeat, chest pain, GI distress and faintness . Several researchers have shown that hyperventilation (rapid respiratory rate and/or increased tidal volume) is a significant factor in the onset and maintenance of panic attacks [11,12]. Studies have also shown that voluntary hyperventilation can induce panic attacks in panic disorder patients [13,14] and that patients with panic disorder demonstrate slower recovery after hyperventilation and are sometimes hypocapnic (exhibit lower than normal CO2 levels) during baseline recordings . Hyperventilation may occur both before and after the attack itself, and can be a chronic condition of which the patient is not aware. . Finally, Klein’s “suffocation alarm hypothesis”  suggests that the respiratory abnormalities associated with panic disorder may be due to a hypersensitivity to CO2.
Respiratory Physiology Based Treatment
Starting in 2008, results from a series of clinical studies utilizing feedback of exhaled carbon dioxide (CO2) and Respiration Rate (RR) as a therapeutic approach for panic disorder were reported. These studies utilized a capnometer (large handheld device with a small monochrome display) displaying real-time and short-term trend display of CO2 plus analog cassette tape recordings of rising and falling tones at specific rates. Patients followed a three-stage protocol observing their RR and CO2, adjusting breathing rate to be synchronous with the tones and adjusting their inspired air maintain their CO2 in the normal range. This breathing protocol was performed twice-daily for four weeks with the target RR pacing tone rates adjusted weekly from 13 to 11 to 9 and 6 breaths-per-minute and was named capnometry-assisted respiratory training (CART).
Freespira® updates the technology used in the previous studies to include a much smaller, custom sensor and a larger, color display and audible and visual instructions to guide the user. The sensor links to the tablet via Bluetooth and the custom Freespira application (App) displays the CO2 and RR feedback parameters and full breathing sessions. Sessions are uploaded to a secure server for remote web access by clinicians to verify adherence and progress.