Management of pulmonary embolism

You are asked to see a 65-year-old patient on the ICU who had been admitted 24 hours

previously following emergency laparotomy for a bleeding duodenal ulcer. He had

been extubated 24 hours previously. His haematology, coagulation and biochemistry

profiles are normal and he was on 30% oxygen but has suddenly become very short of

breath with some pleuritic central chest pain. He is cardiovascularly stable. You suspect

a possible pulmonary embolism (PE) and start him on high-flow oxygen. Which of the

following statements represents your BEST immediate management plan?

a) 12-lead electrocardiogram (ECG), blood for cardiac troponin, computerised

tomography pulmonary angiogram (CTPA) and therapeutic dose unfractionated

heparin if the CTPA shows a significant PE

b) 12-lead ECG, CTPA and thrombolytic therapy if the CTPA shows a significant PE

c) 12-lead ECG, CTPA and therapeutic dose unfractionated heparin if the CTPA

shows a significant PE

d) CTPA and therapeutic dose enoxaparin sodium if the CTPA shows a significant PE

e) 12-lead ECG, D-dimer and if both are normal no further immediate interventions

Answer: C

Explanation

There is a great deal of information in this question that takes some sifting through.

Option (a) is incorrect because cardiac troponin taken at the onset of chest pain is of little

prognostic significance, particularly in a patient who has been critically ill. Option (e) is

incorrect because a combination of a negative 12-lead ECG and D-dimer is not sensitive

enough to exclude a diagnosis of PE. Option (d) can be discounted because an ECG

should be done to exclude any obvious ST elevation or other evidence of myocardial

ischaemia, and it would be unwise to start a low molecular weight heparin rather than

unfractionated heparin in a patient on critical care following recent surgery, due to the

risk of bleeding. Of note the often-quoted, classic ‘S1, Q3, T3’ pattern seen on an ECG in

pulmonary embolus is extremely uncommon. This leaves Options (b) and (c). A 2006

Cochrane Review showed that, based on the limited available evidence, it was unclear

whether thrombolytic therapy was better than heparin for pulmonary embolism. The

reviewers felt that more double-blind randomised controlled trials, with subgroup

analysis of patients presenting with haemodynamically stable acute pulmonary embolism

compared to those patients with a haemodynamic unstable condition, were

required. In addition, thrombolytic therapy in a patient who has recently undergone

laparotomy for a bleeding duodenal ulcer may be potentially hazardous.

Reference

Dong BR, Hao Q, Yue J, Wu T, Liu GJ. Thrombolytic therapy for pulmonary embolism.

Cochrane Database of Systematic Reviews 2009, 3. CD004437. Summary online at www.

cochrane.org/reviews/en/ab004437.html (Accessed 30 October 2009)