Question 21

College Answer

Causes:

Abdominal trauma
Massive retroperitoneal hematomas

Major burns following fluid resuscitation

Massive intra-abdominal hemorhage

Major Consequences:
a)  Decrease in Qt because of a decrease in venous return

b)  Decreased renal perfusion

c)  Impaired thoracic compliance

d)  Bowel ischemia

Management
a)  Monitoring intra-abdominal pressure

b)  Abdominal decompression

c)  Adequate decompression of GI tract

d)  Avoiding excess fluid resuscitation

Discussion

A slightly more formal-looking exploration of abdominal compartment syndrome can be found in Question 8 from the first paper of 2013. Brief notes on the pathophysiology of abdominal compartment pressure and its measurement are available, with references for the time-rich exam candidate.

Causes of abdominal compartment syndrome:

Primary ACS: increased compartment pressure due to abdominal pathology

• Massive ascites, eg. portal vein thrombosis
• Retroperitoneal hematoma
• Abdominal trauma with crush injury

Secondary ACS: increased compartment pressure due to fluid resuscitation

• Abdominal infection eg peritonitis
• Pancreatitis
• Major trunk burns with massive fluid resusicitation (thus, restriction of abdominal expansion)

Consequences of abdominal compartment syndrome:

• Hypotension due to decreased preload
• Renal failure due to decreased renal blood flow (venous and arterial)
• Lactic acidosis due to impared hepatic blood flow
• Gastric erosions and ulceration due to impaired gastric blood flow
• Intestinal ischaemia due to impaired intestinal blood flow
• Poor gut transit, ileus, and decreased tolerance of NG feeds
• Decreased FRC and therfore increased atelectasis, worsening gas exchange, decreased compliance of the respiratory system, leading to hypoxia and hypercapnea
• Raised intracranial pressure

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)

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.

 

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.