GI bleeding and abdominal emergencies

Intra-abdominal hypertension and compartment syndrome

Reviewed Nov 2026·1 references
New· views rounded down, updated weekly

Measure IAP correctly, grade IAH, and treat ACS with the WSACS stepwise approach up to decompressive laparotomy.

Definition
IAH = sustained IAP ≥ 12 mmHg (grade I 12-15, II 16-20, III 21-25, IV > 25). Abdominal compartment syndrome = sustained IAP > 20 mmHg with new organ dysfunction. APP = MAP - IAP (target ≥ 60 mmHg).

At the bedside

  1. 1

    Who to measure

    Two or more risk factors: massive fluid resuscitation/positive balance, massive transfusion, pancreatitis, abdominal surgery/trauma, ileus, ascites, burns, prone position, high PEEP, obesity, sepsis.

  2. 2

    Measure via bladder

    Supine, end-expiration, transducer zeroed at mid-axillary line at iliac crest, instil ≤ 25 mL sterile saline, wait 30-60 s, read in mmHg. Repeat 4-6 hourly in IAH.

  3. 3

    Evacuate intraluminal contents

    Nasogastric and rectal decompression, prokinetics, enemas, endoscopic decompression.

  4. 4

    Evacuate intra-abdominal fluid

    Percutaneous drainage of ascites/collections (ultrasound-guided).

  5. 5

    Improve wall compliance

    Adequate analgesia/sedation, avoid head-up > 30°, remove tight dressings/binders, neuromuscular blockade trial for refractory cases.

  6. 6

    Optimise fluids

    Avoid positive fluid balance after initial resuscitation; diuretics or ultrafiltration (RRT); use hypertonic/colloid if appropriate.

  7. 7

    Decompressive laparotomy

    For refractory ACS with organ dysfunction; temporary abdominal closure (vacuum).

IAH grading

GradeIAP (mmHg)
I12-15
II16-20
III21-25
IV> 25
ACS> 20 + new organ dysfunction
Red flag · call your senior now
Rising airway pressures, oliguria and falling cardiac output in a tense distended abdomen: measure IAP now.
Pitfall
Measuring IAP with the patient head-up, with active abdominal muscle contraction, or using > 25 mL saline: falsely high.
Pitfall
Treating oliguria from ACS with more fluid boluses.
Pearl
Clinical examination of abdominal tension is unreliable; measure.

Calculators for this topic

Mean arterial pressure

(SBP + 2 × DBP) ÷ 3 (estimate; use the arterial line value when available).

References

  1. 1

    Kirkpatrick AW, Roberts DJ, De Waele J, et al. Intra-abdominal hypertension and the abdominal compartment syndrome: updated consensus definitions and clinical practice guidelines from the World Society of the Abdominal Compartment Syndrome. Intensive Care Med 2013;39:1190-206.

Test yourself

Module quiz · score 70% to complete the module

Previous

Severe acute pancreatitis

Next

Acute mesenteric ischaemia

Educational reference for trained clinicians. Check doses against your hospital protocol and the patient in front of you.