CHEST PAIN46 General Medical Emergencies
2 Give aspirin 150–300 mg orally unless contraindicated by known hyper -
sensitivity.
(i) Give clopidogrel 300 mg oral loading dose, then 75 mg orally
once daily, if aspirin intolerant or in addition to aspirin if this is
local policy.
3 Maximize pain relief:
(i) Give glyceryl trinitrate (GTN) 150–300 g sublingually,
maintaining systolic blood pressure (BP) above 100 mmHg and
avoiding excessive hypotension.
(ii) Add morphine 2.5–5 mg i.v. with an antiemetic, e.g.
metoclopramide 10 mg i.v., if pain persists.
4 Reperfusion therapy
Consider reperfusion therapy in consultation with the senior ED doctor.
Aim to either commence thrombolysis within a maximum of 30 min of the
patient’s arrival in hospital, without delay by transferring to the CCU, or
arrange for percutaneous coronary intervention (PCI) if this is available in
under 60–90 min.
5 Thrombolysis
This is indicated within 12 h (ideally 6 h) of the onset of myocardial ischaemic
pain in patients with a STEMI, e.g. ECG evidence of ST elevation MI, with ST
elevation of at least 1 mm in two contiguous limb leads or 2 mm in two con-
tiguous precordial chest leads, and for new bundle branch block, particularly
left bundle branch block (LBBB).
(i) Absolute contraindications to thrombolysis:
(a) intracerebral or subarachnoid haemorrhage ever, intracranial
malignancy
(b) thrombotic stroke in previous 3 months
(c) known bleeding diathesis or active bleeding (excluding
menses)
(d) significant head or facial trauma in previous 3 months
(e) aortic dissection (see p. 57).
(ii) Relative contraindications (thrombolysis may still be considered
in those at highest risk of death, or with greatest net clinical
benefit, such as a large anterior infarction presenting within 3 h
of symptom onset):
(a) oral anticoagulant therapy
(b) pregnancy or within 1 week post partum
(c) major surgery in last 3 weeks
(d) non-compressible arterial puncture or central line
(e) refractory hypertension (systolic BP over 180 mmHg,
diastolic BP over 110 mmHg)
(f) history of severe or poorly controlled hypertension
(g) prolonged CPR over 10 min
(h) severe hepatic or renal disease.