Emergency Medicine

ACUTE ABDOMEN

Surgical Emergencies 265

Ruptured abdominal aortic aneurysm

DIAGNOSIS

1 This classically presents with sudden abdominal pain radiating to the back
or groin, syncope, collapse or unexplained shock. Tachycardia and hypo-
tension occur in 50% of cases.

2 Feel for a tender mass with expansile pulsation on examination, or a vague
fullness with discomfort to the left of the umbilicus.

3 Always consider this diagnosis in men >45 years in particular, even when
only one feature of the ‘classic triad’ of abdominal or back pain, shock, and a
pulsatile or tender abdominal mass is present.
(i) Also consider a ruptured AAA first in the older patient with
apparent ‘ureteric colic’.

4 Gain large-bore i.v. access in both arms and send blood for FBC, U&Es,
blood sugar, lipase/amylase and cross-match up to 10 units of blood.

5 Catheterize the bladder.

6 Record the ECG because ischaemic heart disease is usually associated with
or exacerbated by the hypotension.

7 Request a CXR if there is time.

8 Perform a rapid bedside ultrasound scan to confirm the presence of an
abdominal aneurysm if the patient is haemodynamically unstable and the
diagnosis is uncertain.

9 Or proceed directly to theatre if the patient is moribund.

10 Only request a CT scan if the patient is haemodynamically stable. Remember
to modify the dose of i.v. contrast depending on the renal function.

MANAGEMENT

(^1) Give the patient high-f low oxygen by face mask and commence a slow i.v.
infusion.
(i) Only give minimal amounts of normal saline or Hartmann’s
(compound sodium lactate), aiming for a systolic blood pressure
of no more than 90–100 mmHg (i.e. minimal volume or
hypotense resuscitation).
(ii) Avoid giving massive fluid volumes, as this leads to
coagulopathy, hypothermia, increases the bleeding and causes a
higher mortality.
2 Refer the patient urgently to the vascular surgical team for immediate
laparotomy.
(i) Contact the duty anaesthetist, alert theatre, and inform ICU.