6.11 Intrabdominal Hypertension

Question 1

A 52-year-old male is admitted to the intensive care unit with a provisional
diagnosis of intra-abdominal hypertension and oliguria.
a) Define intra-abdominal hypertension (IAH) and abdominal
compartment syndrome.

Answer 1

● Intra-abdominal hypertension —
sustained abdominal pressure above 12mmHg.

● Abdominal compartment syndrome —
sustained intra-abdominal pressure >20mmHg
associated with organ dysfunction/failure.

Question 2

b) Name any four causes of IAH.

Answer 2

● Blunt or penetrating abdominal trauma.

● Haemorrhage — AAA rupture.

● Intestinal obstruction.

● Pregnancy.

● Ascites.

● Ileus.

● Burns.

● Intra-abdominal sepsis.

● Cirrhosis.

● Obesity.

● Intra-abdominal malignancy.

Question 3

c) What are the pathophysiological consequences of abdominal
compartment syndrome?

Answer 3

● Cardiac —
decreased venous return
and increased SVR leading to
decreased cardiac output and hypotension.

● Pulmonary —
decreased thoracic volumes,
a decrease in the P/F ratio and hypercarbia.

● Renal —
decreased GFR and low urine output.

● Abdominal viscera —
decreased perfusion.

● Neurologic symptoms can include
increased ICP and a decrease in
cerebral perfusion pressure (CPP).

Question 4

d) How would you grade the severity of the IAH?

Answer 4

● Grade I — intra-abdominal pressure 12-15mmHg.

● Grade II — intra-abdominal pressure 16-20mmHg.

● Grade III — intra-abdominal pressure 21-25mmHg.

● Grade IV — intra-abdominal pressure >25mmHg.

Question 5

e) What techniques could be used to measure intra-abdominal
pressure?

Answer 5

Direct method:
● Using pressure transducers
(needle or intraperitoneal catheters).

Indirect method:
● Intravesicular catheter pressures
(e.g. Foley catheter).

Question 6

f) How would you manage the IAH in this patient?

Answer 6

Non-invasive:
● NG tube placement for gastric decompression.

● Rectal tube placement for colonic decompression.

● Neuromuscular blockade to decrease
abdominal compartment pressures
in the ventilated ICU patient

Invasive:
● Percutaneous drainage of abscesses, ascites or fluid from the
abdominal compartment.

● Surgical decompression.

The prevention and early treatment of the potential
cause may prevent the
progression of IAH to abdominal compartment syndrome.