title: Primary Hyperventilation in the Emergency Department: A First Overview.
abstract: BACKGROUND
  Primary hyperventilation is defined as a state of alveolar ventilation in excess of metabolic requirements, leading to decreased arterial partial pressure of carbon dioxide. The primary aim of this study was to characterise patients diagnosed with primary hyperventilation in the ED.
  
  
  METHODS
  Our retrospective cohort study comprised adult (≥16 years) patients admitted to our ED between 1 January 2006 and 31 December 2012 with the primary diagnosis of primary (=psychogenic) hyperventilation.
  
  
  RESULTS
  A total of 616 patients were eligible for study. Participants were predominantely female (341 [55.4%] female versus 275 [44.6%] male respectively, p <0.01). The mean age was 36.5 years (SD 15.52, range 16-85). Patients in their twenties were the most common age group (181, 29.4%), followed by patients in their thirties (121, 19.6%). Most patients presented at out-of-office hours (331 [53.7%]. The most common symptom was fear (586, 95.1%), followed by paraesthesia (379, 61.5%) and dizziness (306, 49.7%). Almost a third (187, 30.4%) of our patients had previously experienced an episode of hyperventilation and half (311, 50.5%) of patients had a psychiatric co-morbidity.
  
  
  CONCLUSIONS
  Hyperventilation is a diagnostic chimera with a wide spectrum of symptoms. Patients predominantly are of young age, female sex and often have psychiatric comorbidities. The severity of symptoms accompanied with primary hyperventilation most often needs further work-up to rule out other diagnosis in a mostly young population. In the future, further prospective multicentre studies are needed to evaluate and establish clear diagnostic criteria for primary hyperventilation and possible screening instruments.
authors.affiliation: Department of Anesthesiology and Intensive Care Medicine, Medical University of Vienna, Vienna, Austria.
authors.forename: Carmen Andrea
authors.initials: CA
authors.lastname: Pfortmueller
authors.affiliation: Department of Emergency Medicine, University Hospital and University of Bern, Bern, Switzerland.
authors.forename: Sandra Elisabeth
authors.initials: SE
authors.lastname: Pauchard-Neuwerth
authors.affiliation: Center of Laboratory Medicine, University Institute of Clinical Chemistry, Inselspital-Bern University Hospital, Inselspital, Bern, Switzerland.
authors.forename: Alexander Benedikt
authors.initials: AB
authors.lastname: Leichtle
authors.affiliation: Center of Laboratory Medicine, University Institute of Clinical Chemistry, Inselspital-Bern University Hospital, Inselspital, Bern, Switzerland.
authors.forename: Georg Martin
authors.initials: GM
authors.lastname: Fiedler
authors.affiliation: Department of Emergency Medicine, University Hospital and University of Bern, Bern, Switzerland.
authors.forename: Aristomenis Konstantinos
authors.initials: AK
authors.lastname: Exadaktylos
authors.affiliation: Department of Emergency Medicine, University Hospital and University of Bern, Bern, Switzerland; Department of Respiratory and Critical Care Medicine, Otto Wagner Hospital Vienna and Ludwig Boltzmann Institute for COPD and Respiratory Epidemiology, Vienna, Austria.
authors.forename: Gregor
authors.initials: G
authors.lastname: Lindner
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004244:Dizziness / Q000150:complications* / Q000175:diagnosis / Q000523:psychology; D004636:Emergency Service, Hospital; D005239:Fear / Q000523:psychology*; D005260:Female; D006801:Humans; D006985:Hyperventilation / Q000150:complications / Q000175:diagnosis* / Q000523:psychology; D008297:Male; D008875:Middle Aged; D010292:Paresthesia / Q000150:complications* / Q000175:diagnosis / Q000523:psychology; D012189:Retrospective Studies; D012720:Severity of Illness Index; D012737:Sex Factors; D063189:Symptom Assessment; D055815:Young Adult