Acute ruptured abdominal aortic aneurysm

Theory

Seventy-five per cent mortality: 50 per cent prior to reaching hospital; 25 per cent after reaching hospital and undergoing surgery.

Best prognostic indicator is level of consciousness at time of arrival to hospital or at time of diagnosis.

Immediate intern management

Suspect and make the diagnosis by examining the abdomen. It’s in your hands.

Sudden onset abdominal and back pain with collapse equals ruptured AAA until proven otherwise. Most have a tender, pulsatile mass to feel.

Large bore x2 IV access.
Basic set bloods (FBE, U&E, INR, X-Match six units).
Nil orally.
IV fluids with caution – aim to maintain urine output, but remember hypotension helps the abdominal muscles to tamponade the bleeding.
Contact the surgical registrar or consultant urgently.

Organise appropriate definitive investigations (depending on advice of surgical registrar and patient’s stability).

CT scan with IV contrast.

If the patient is too haemodynamically unstable for CT scan, has hypotension not responding to IV fluid challenge and persistent tachycardia, an immediate exploratory laparotomy is indicated.

Clinical features

History

Middle aged to elderly
Presents with sudden onset severe epigastric pain with collapse
Pain radiates to back and sometimes into groin
Vascular risk factors

Examination

Tachycardic
Hypotensive
Pale, sweaty (SHOCK)
Conscious/moribund
Tender expansile pulsatile mass in epigastrium
May feel tense or may be hard to feel
Weak or absent peripheral pulses
Cool peripheries

Differential diagnosis

Perforated viscus
Acute pancreatitis
Aortic dissection
Enlarging aortic aneurysm
Ruptured splenic artery aneurysm

Investigations (urgent) diagnostic

Abdominal CT scan with IV contrast
The patient may not be stable enough following rupture to undergo CT scan. Persistent hypotension and tachycardia not responding to fluid challenge is an indication for urgent surgical exploration.
X-Match six units
Routine set blood tests

Definitive management

Once diagnosis is made, definitive management rests with emergency laparotomy and clamping aorta above site of rupture.

The patient may be stable enough for transfer to a specialist vascular unit. Otherwise surgical management focuses on:

Transfer urgently to operating theatre
Organise invasive monitoring: pulse oximetry, arterial line, IDC, central venous line (some of these may be done in theatre)
Prep skin and theatre team ready
Crash induction and intubation while surgical team performs laparotomy, confirm diagnosis and clamp aorta proximal to site of rupture

Patients being transferred require the above invasive monitoring

Practical tips

The diagnosis rests with a history of sudden onset abdominal and back pain with collapse
The abdominal findings are your chance to save time and life by clinching the diagnosis clinically. Distension or tense muscles may mask the tender pulsatile mass.
If the patient is too unstable for a CT scan then they need an urgent exploratory laparotomy
Inform superiors early

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