Interaction of panic and episodic breathlessness among patients with life-limiting diseases: a cross-sectional study.

Background: Episodic breathlessness is often accompanied by panic. A vicious cycle of breathlessness-panic-breathlessness leads to emergencies with severe breathlessness and/or fear of dying. However, the interaction between episodic breathlessness and panic is poorly understood. Thus, the aim is a better understanding of the interaction between panic and episodic breathlessness to develop appropriate support for patients suffering from this symptom.
Methods: Patients suffering from episodic breathlessness due to life-limiting diseases answered questions on the characteristics of episodic breathlessness and panic-spectrum psychopathology, including underlying mechanisms. Using the Patient Health Questionnaire and the Structured Clinical Interview for DSM-IV Diagnoses (SCID), patients were screened for panic disorder. An open-ended question captured the patients' descriptions of panic during breathlessness episodes.
Results: Forty-six patients [52% women, mean age =66 years; standard deviation (SD) 7.3 years] provided information: 61% suffered from panic during the entire breathlessness episode, 39% experienced panic in every episode, and 25% were diagnosed with panic disorder. Exploratory data analysis was conducted. Patients with high scores in breathlessness catastrophizing thoughts experienced more panic in a breathlessness episode (P<0.001) and considered themselves more panic than low-scorers (P=0.024). There was a significant indirect effect of episodic breathlessness intensity on the panic experienced in an episode, and this effect was mediated by catastrophizing thoughts regarding breathlessness (b=0.164; 95% CI: 0.105, 0.222). Patients described in the open-ended question experiencing only panic or breathlessness, or a combination of both. Some patients managed to differentiate panic from episodic breathlessness, and used strategies to avoid panic in an episode.
Conclusions: Research on treatment options for episodic breathlessness should not only focus on panic in breathlessness episodes, but also on underlying mechanisms such as catastrophizing thoughts, as they aggravate the burden.