Describe the effects of the Intra-abdominal Compartment Syndrome.  Outline your method for measuring intra-abdominal pressure and explain the pitfalls of this method.

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College Answer

Discussion on the effects of the ICS should include:

•    renal effects – capillary compression, decreased GFR/UO, ATN,

•    bowel – decreased SMA/coeliac flow, decreased pHi, bowel ischaemia

•    hepatic – decreased portal blood flow, lactate clearance

•    cardiac –decreased venous return/cardiac output, elevated PAOP/CVP/afterload

•    respiratory –increased PIP, shunt, Paw,

•    cerebral – increased ICP, decreased CPP

Description of a simple, sterile and practical technique for measurement of intra-vesical pressure was expected.

Pitfalls include:

•    using the wrong zero point

•    allowing a leak in the system to produce a falsely low reading

•    chronic cystitis, radiation cystitis producing a small contracted bladder with low compliance which gives a falsely high reading

•    pelvic haematoma producing a tight pelvic compartment with falsely elevated IAP.

Discussion

The majority of this question is answered by the discussion of Question 8 from the first paper of 2013. A slightly less formal discussion of abdominal compartment syndrome takes place in Question 21 from the second paper of 2006: "Outline the causes, consequences and the management of abdominal  compartment syndrome. "

The "pitfalls" section is not addressed anywhere else.

Briefly, the following are reasons as to why one's intrabdominal measurements may be wrong:

  • Failure of technique
    • Improper setup of the measuring set
    • Improperly calibrated transducer
    • Inappropriate zero point
    • Leaking transducer system
  • Confounding factors
    • Increased pelvic pressure
    • High detrusor tone
    • Detrusor fibrosis
    • Incompletely paralysed patient