44 General Medical Emergencies

DIFFERENTIAL DIAGNOSIS

Always consider the life-threatening diagnoses first:

● Acute coronary syndrome (ACS), such as myocardial infarction or unstable

angina.

● Pulmonary embolus.

● Aortic dissection.

Other causes to consider include:

● Pericarditis.

● Pleurisy.

● Pneumonia.

● Pneumothorax.

● Abdominal – oesophagitis, oesophageal rupture, gall bladder disease, etc.

● Musculoskeletal and chest wall pain.

Acute coronary syndrome

The term acute coronary syndrome encompasses the spectrum of patients

presenting with chest pain or other symptoms due to myocardial ischaemia

that ranges from ST elevation myocardial infarction (STEMI), non-ST

elevat ion myoca rd ia l i n fa rc t ion (NSTEM I) to u nstable a ng i na pec tor is (UA). T he

common pathophysiology of ACS is rupture or erosion of an atherosclerotic

plaque.

ST ELEVATION MYOCARDIAL INFARCTION (STEMI)

DIAGNOSIS

1 Predisposing factors include cigarette smoking, hypertension, diabetes,

hypercholesterolaemia, male sex, increasing age and a positive family

history.

2 There may be a prior history of angina, myocardial infarction or heart

failure, or alternatively the condition may arise de novo.

3 ‘Typical’ pain is central, heavy, burning, crushing or tight retrosternal,

usually lasting for several minutes or longer, unrelieved by sublingual

nitrates, and is associated with anxiety, dyspnoea, nausea and vomiting.

CHEST PAIN

Warning: patients with these can present initially with few physical signs

and or a non-diagnostic chest radiograph (CXR) and electrocardiogram

(ECG), so may have to be managed on clinical suspicion alone. Attach a

cardiac monitor and pulse oximeter to the patient, establish venous access

and give 35% oxygen.

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