Intra-Abdominal Pressure Monitor

Reviewed and revised 15 August 2014


  • device used to assess intra-abdominal pressure (IAP)
  • intra-abdominal pressure is the steady state pressure concealed within the abdominal cavity


  • measurement of intra-abdominal pressure in patients at risk of, or suspected of having, abdominal compartment syndrome


  • can be performed using proprietary devices
  • requires pressure transducer set up connected to indwelling urinary catheter
  • one approach is to cross-clamp the tubing of the drainage bag and insert a 16-gauge needle through the aspiration port, which is connected to a pressure transducer
  • Alternatively, a T-piece connector or a three- way stopcock is inserted between the catheter and the drainage bag


Intra-abdominal pressure measurement (IAP) = bladder pressure (mmHg) when the following criteria fulfilled:

  • end of expiration
  • supine
  • zeroed at iliac crest in the mid-axillary line (WSACS recommendation; other sources suggest using the pubic symphysis)
  • instillation of 25mL of saline into the bladder (1ml/kg for children up to 25 kg, minimum of 3 mL)
  • measured  60 seconds after instillation to allow detrusor muscle relaxation
  • in absence of active abdominal muscle contraction

Usually measured every 4 hours (more frequent if IAP >12mmHg or otherwise concerned)


  • as for IDC
  • falsely high readings from chronic or radiation cystitis or pelvic haematoma
  • falsely low readings if there is a leak in the system



  • IAP is normally ~ 5–7 mmHg in critically ill adults
  • intra-abdominal hypertension (IAH) is defined by a sustained or repeated pathological elevation in IAP ≥ 12 mmHg
  • abdominal compartment syndrome (ACS) is defined as a sustained IAP > 20 mmHg (with or without an abdominal perfusion pressure (APP) < 60 mmHg) that is associated with new organ dysfunction/failure

Grades of IAH

  • Grade I = IAP 12–15 mmHg
  • Grade II = IAP 16–20 mmHg
  • Grade III = IAP 21–25 mmHg
  • Grade IV = IAP > 25 mmHg

References and Links


Journal articles

  • Kirkpatrick AW, 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 Jul;39(7):1190-206. PMC3680657.

FOAM and web resources

CCC 700 6

Critical Care


Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also a Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.

After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.

He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE.  He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.

His one great achievement is being the father of three amazing children.

On Twitter, he is @precordialthump.

| INTENSIVE | RAGE | Resuscitology | SMACC

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