Question 1

a)    Define intra-abdominal hypertension (IAH) and intra-abdominal compartment syndrome (ACS). (20% marks)

b)    Describe how intra-abdominal pressure (IAP) is commonly measured.    (40% marks)

c)    Briefly outline the management principles of intra-abdominal compartment syndrome (ACS). (40% marks)

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College answer

Not available.


a)  Definitions

  • Intra-abdominal hypertension is a sustained or repeated pathological elevation in IAP≥12 mmHg.
  • Abdominal Compartment Syndrome is defined as a sustained IAP>20 mmHg that is associated with new organ dysfunction.
    (normal intraabdominal pressure ranges from subatmospheric to 0 mmHg in normal healthy adults, and around 5-7 mmHg in the prostrate ventilated critically ill patient)

b) Measurement

  • Empty the bladder
  • Clamp IDC
  • Attach noncompressible tubing and transducer
  • Inject 20ml of fluid into the bladder
  • Wait for the detrusor to relax (60 seconds)
  • Zero the transducer to atmosphere, at mid-axillary line and at the level of the iliac crest
  • Measure the pressure at end-expiration
  • The measurement is valid under the following conditions:
    • Patient is supine
    • Muscle contraction is eliminated (eg. NMJ blockers)

c) Management of abdominal compartment syndrome:

  • Prevention:
    • Avoid overvigorous fluid resusictation
    • Patients at risk of ACS should perhaps remain open-abdomen after largescale abdominal surgery
    • monitor the compartment pressure
  • Management
    • Staged closure of abdominal defect
    • Vasopressors to maintain MAP within a certain range (some aim for an abdominal perfsion pressure of >60mmHg)
    • Titrate PEEP to optimise V-Q matching, to maintain normoxia and normocapnea
    • If compartment pressure remains elevated, neuromuscular blockade can be considered
    • If pressure remains high in spire of NMJ blockade, may consider opening the abdomen (if it is closed)


Malbrain, Manu LNG, et al. "Results from the international conference of experts on intra-abdominal hypertension and abdominal compartment syndrome. I. Definitions." Intensive care medicine 32.11 (2006): 1722-1732.

Cheatham, Michael L., et al. "Abdominal perfusion pressure: a superior parameter in the assessment of intra-abdominal hypertension." Journal of Trauma-Injury, Infection, and Critical Care 49.4 (2000): 621-627.

Bailey, Jeffrey, and Marc J. Shapiro. "Abdominal compartment syndrome."Critical Care 4.1 (2000): 23.

Cheatham, Michael Lee. "Abdominal compartment syndrome." Current opinion in critical care 15.2 (2009): 154-162.

Maerz, Linda, and Lewis J. Kaplan. "Abdominal compartment syndrome."Critical care medicine 36.4 (2008): S212-S215.

Saggi, Bob H., et al. "Abdominal compartment syndrome." Journal of Trauma-Injury, Infection, and Critical Care 45.3 (1998): 597-609.