Development of a Decision Support System in the Assessment of Patients With Chest Pain in the Prehospital Setting

Prehospital emergency care has undergone dramatic changes in recent decades. From the fact that the ambulance nurse has previously started care at the site of the illness, with the goal of transporting the patient to the nearest emergency room, prehospital care has become increasingly differentiated. This means that "care at the right level of care" has become a watchword and a number of different levels of care have become relevant, ranging from fast track and rapid investigation and treatment in hospital for heart attack, acute myocardial infarctions and strokes to the patient being left at the scene with advice on self-care.

In principle, there is three overall levels of care:1) Need for inpatient resources;2) Need for primary care contact or visit by mobile healthcare team within the next day and 3) Referral to home care, provide support for self-care or treatment on site.

This places competence requirements on the ambulance nurse with requirements for a prehospital assessed condition compatible with a level of care where the patient's needs can be met. This approach puts patient safety in focus in a different way than before. Because with this procedure, patients with time-sensitive conditions (such as stroke, heart attack, acute myocardial infarction and sepsis) run an increased risk of being left at the scene with advice on self-care, due to inappropriate prehospital assessment. In prehospital emergency care, the assessment of the severity of the patient's condition takes place in two stages: 1) At the emergency dispatch centre when the patient has called the national emergency number and 2) At the scene of the illness by the ambulance nurse after arrival at the patients side.

The basis for prehospital decision support is a) identification of time-sensitive conditions, i.e. conditions where the time to initiation of causal treatment can affect the prognosis, and b) identification of predictors, i.e. factors that are already prehospitally characteristic of the condition (disease or accident) itself, but also of the severity of the condition. The classic examples of time-critical conditions are manifestations of cardiovascular diseases such as heart attack ,acute myocardial infarction and stroke, but also serious infectious diseases such as sepsis and severe trauma. Predictors can be identified via measurement of vital parameters such as pulse, blood pressure and oxygen saturation, medical history (previously known diseases and current onset), current symptom picture, clinical manifestations ( pallor) examination findings (ECG) and analysis of biochemical markers by capillary blood test (glucose, troponin).

Current studies indicate that for many patients in contact with the emergency medical service due to acute chest pain, other options than the emergency department, e.g. follow-up in primary care, may be more beneficial for the patient and less resource-intensive for the ambulance and the emergency care. In these cases, a decision support system based on gender, medical history, symptoms and clinical observations including ECG and and biochemical markers, (troponin) could provide support for the ambulance nurse. Chest pain is one of the most common search causes and constitutes about 10% of assignments in the Swedish emergency medical service.