Prehospital Triage of Patients With Severe Shortness of Breath Using Biomarkers
Prehospital Triage of Patients With Severe Shortness of Breath Using Biomarkers
Breathlessness is a dangerous symptom. Preliminary data from national and regional Danish
 databases show, that patients with shortness of breath in the ambulance have a very high
 mortality. Breathlessness can be caused by many different conditions - but heart diseases and
 lung diseases are dominant. The mortality is especially high in patients with breathlessness
 caused by heart disease.

 Distinguishing these different causes of breathlessness is a classical, often difficult,
 discipline in medicine. Visitation and guidance of treatment in patients with breathlessness
 in the prehospital setting relies on medical history and physical examination and as a
 consequence prehospital treatment for breathlessness is often non-specific. The use of
 heart-failure specific biomarkers may improve prehospital visitation and treatment of
 patients with breathlessness.

 We hypothesize, that

 1. Supplementing the routine examination by prehospital anesthesiologist with measurement
 of a biomarker for heart failure increases the proportion of patients with severe
 shortness of breath caused by heart disease triaged directly to department of cardiology

 2. This strategy does not increase the proportion of patients with severe shortness of
 breath caused by non-heart disease triaged directly to department of cardiology
Measurement of the biomarker for heart failure N-terminal pro-Brain Natriuretic Peptide
 (NT-proBNP):

 In patients randomized to the strategy with supplementary measurement of NT-proBNP, a blood
 sample will be drawn from the peripheral venous catheter that is routinely inserted. This
 will be analyzed point-of-care in the ambulance.

 Interpretation of NT-proBNP:

 Cut-off values based on bootstrap-validated optimal cut-points for heart failure on will be
 used.

 Confirmatory ('rule in') cut point

 < 50 years: 450 pg/mL

 50-75 years: 900 pg/mL

 > 75 years: 1800 pg/mL

 Exclusionary ('rule out') cut point

 All patients: 300 pg/mL

 The emergency physicians will be thoroughly informed about these cut-points, but told not to
 triage to department of cardiology or other department strictly according to NT-proBNP, but
 according to clinical assessment AND NT-proBNP.
Inclusion Criteria:

 All patients requiring dispatch of emergency physician because of severe dyspnea.

 Severe dyspnea is defined by dyspnea plus at least ONE of the following

 -  Respiration frequency > 20 or < 8

 -  Saturation < 96 without supplementary oxygen

 -  Heart rate > 100 or < 50

 -  Systolic blood pressure < 100 or > 200

 -  Difficulty talking

 -  Central or peripheral cyanosis

 -  Use of accessory muscles of respiration

 -  Glasgow coma scale score < 15

 AND because of the physical condition, the patient is not able to give informed consent

 Exclusion Criteria Age < 18