UMEM Educational Pearls

 

With ED-boarding of critically-ill patients becoming more common, it is likely that ED physicians may find themselves caring for a patient who develops ACS – that is, abdominal compartment syndrome. While intraabdominal hypertension (IAH) is common and is defined as intraabdominal pressure > 12 mmHg, ACS is defined as a sustained intraabdominal pressure > 20mmHg with associated organ injury.

 

WHY you need to know it:

ACS → Increased mortality & recognition is key to appropriate management

 

WHO is at risk:

• Decreased abdominal wall compliance (obese, post-surgical)
• Increased intrabadominal contents (hemoperitoneum, ascites, tumor)
• Increased intraluminal contents (gastroparesis, ileus)
• Capillary leak / aggressive fluid resuscitation (sepsis, burns)

 

HOW it kills:

• Decreased blood flow to organs due to extraluminal pressure (mesenteric, renal, hepatic ischemia)
• Decreased diaphragmatic mobility, hypoventilation/oxygenation
• Decreased venous return, decreased cardiac output

→ Lactic acidosis, respiratory acidosis, multisystem organ failure, cardiovascular collapse & death

 

WHEN to consider it:

• Most patients who develop ACS are already intubated or altered – but consider in responsive patients c/o severe abdominal pain, marked distension, and SOB with tachypnea
• Intubated patients – recurrent, ongoing high pressure alarms with relatively low lung volumes, tachypnea
• Abdomen distended and minimally ballotable
• New / worsening oliguria / anuria
• Labs demonstrate increased creatinine, LFTs, lactate elevated “out of proportion” to patient presentation prior to decompensation 
• Imaging may reveal underlying etiology or sequelae of ACS but cannot rule it out

 

WHAT to do:

1. Confirm diagnosis with bladder pressure (via urinary catheter) *see cited paper for how-to in the ED*
2. Emergent surgical consultation (emergent laparotomy → improved hemodynamics, organ function, & survival. 
3. Optimize abdominal perfusion pressure (MAP - intraabdominal pressure; recommended > 60mmHg) as much as possible:

• Adequate analgeisia and sedation, if needed, to avoid agitation
• Avoid intubation if able, to avoid the positive pressure. In intubated patients, aim for low PEEPs and plateau pressures and consider short-term paralytic
• Lower the head of bed (supine to 30mmHg) to minimize abdominal "crunch"
• Aim for intravascular euvolemia. If volume overload is a contributing factor then IVF for hypotension will worsen the ACS -- start vasopressor instaed
• Evacuate intraluminal contents if able (NGT/rectal tube for decompression, consider erythromycin/reglan, or neostigmine for colonic pseudoobstruction)
• Evacuate intraabdominal extraluminal contents if able (therapeutic paracentesis for ascites(
• Burn patients with restrictive abdominal eschar should get escharotomy

 

Bottom Line: Abdominal compartment syndrome is an affliction of the critically ill, is assosciated with worsened mortality, and requires aggressive measures to lower the intraabdominal pressure while obtaining emergent surgical consultation for potential emergent laparotomy. 

 

References

Gottlieb M, Koyfman A, Long B. Evaluation and Management of Abdominal Compartment Syndrome in the Emergency Department. J Emerg Med. 2019.  https://doi.org/10.1016/j.jemermed.2019.09.046