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Enrolling by invitationNCT07563842WSACSUpdated May 4, 2026

Updated Abdominal Compartment Society Consensus Definitions

An observational study in Abdominal Hypertension and Abdominal Compartment Syndrome, sponsored by Medical University of Lublin. Enrolling by invitation at 1 site in Poland. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-05-04.

Sponsored by Medical University of Lublin · Observational

From the registry’s dates

  • Primary completion was expected by Jul 2026, 3 months ago, but the record still lists the study as enrolling by invitation.
Study type
Observational
Model
Cohort
Time perspective
Prospective
Enrollment
60
Ages
18 Years and older
Sex
All
01

Study summary

An international team of experts is working on a project called updated WSACS consensus definitions. The goals of this study are to:

  1. To generate expert consensus on the definitions and classification of IAH and ACS.
  2. To generate expert consensus on definitions regarding the pathophysiology of IAH and ACS.
  3. To generate consensus on definitions regarding the methods of measurement of intra-abdominal pressure (IAP).
Read the detailed description

Intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) are frequently encountered in critically ill or injured patients and remain associated with significant morbidity and mortality. IAH is defined as a sustained increase in intra-abdominal pressure (IAP) equal to or above 12 mmHg. It is diagnosed in approximately one-third of mixed medical and surgical intensive care unit (ICU) patients at admission and develops in about half during the first week of ICU stay. IAH has consistently been shown to be an independent predictor of adverse outcomes, including multi-organ dysfunction and death.

Following the original consensus definitions and subsequent guideline updates by the Abdominal Compartment Society (WSACS), the understanding and management of IAH and ACS have evolved substantially. While surgical etiologies such as trauma and ruptured abdominal aortic aneurysm were historically predominant, more recent data highlight that IAH and ACS frequently occur in medical ICU populations as well. Contributing factors include excessive fluid resuscitation, massive transfusion, venous congestion, and capillary leak, which can lead to secondary IAH and subsequent organ failure even in the absence of direct abdominal pathology.

Despite the availability of consensus guidelines and an improved understanding of the pathophysiology, it remains unclear whether prevention or active treatment of IAH directly improves patient outcomes. Furthermore, there is growing recognition of the need to refine the definitions, measurement techniques, and classification systems for IAH and ACS to reflect current clinical knowledge and practice across diverse healthcare settings.

The WSACS - The Abdominal Compartment Society - previously published comprehensive consensus definitions and recommendations in 2013. Since then, new research has provided additional insights into epidemiology, measurement technologies, classification systems, and the broader clinical implications of IAH and ACS. A recent global survey among healthcare professionals identified emerging areas of uncertainty and priority topics for definition updates.

In response, this study will conduct an international modified Delphi process to achieve expert consensus on updated definitions and clinical practice statements for IAH and ACS. The Delphi method will systematically collect and refine expert opinions over several iterative rounds, with the goal of reaching agreement on revised definitions, measurement approaches, pathophysiological frameworks, and classification criteria.

The outcome of this Delphi process will be a set of updated, evidence-informed, and globally endorsed definitions and recommendations for IAH, ACS, and the open abdomen. These consensus statements aim to harmonize terminology, support clinical decision-making, guide future research, and ultimately improve patient care. The target audience includes physicians, surgeons, intensivists, anesthesiologists, nurses, and policymakers involved in the management of critically ill or injured patients across both high- and low-to-middle-income countries.

02

Conditions studied

  • Abdominal Hypertension
  • Abdominal Compartment Syndrome

Keywords

  • abdominal hypertension
  • abdominal compartment syndrome
  • definitions
  • pathophysiology
  • measurement
  • intra-abdominal pressure
  • intra-abdominal volume
03

In context

Intra-Abdominal Hypertension

71 studies on the registry are indexed under Intra-Abdominal Hypertension; 16 are open to participants now.

This study's planned enrollment of 60 is below the median of 98 across 36 observational studies indexed under Intra-Abdominal Hypertension.

Browse Intra-Abdominal Hypertension studies →

Lead sponsor

Medical University of Lublin is the lead sponsor of 62 studies on the registry; 11 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
Yes
Sampling method
Non-probability sample

Study population

Inclusion Criteria: Panellists will be identified based on either of the following criteria At least 5 years of clinical experience as a staff member in Anesthesiology, Surgery or Intensive Care Medicine with involvement in care of patients with postoperative complications Author of at least one publication (observational studies or randomised controlled trials) on intra-abdominal hypertension or abdominal compartment syndrome. For patients and public involvement Individuals who have either personally experienced IAH or ACS following surgery or ICU within the last 5 years or, primary caregivers of such patients will be recruited as patient care representatives. Proficiency in English is required. To mitigate potential bias, patient care representatives mustn't maintain a professional or advisory relationship with the steering committee or panellists. Co-authors from previous WSACS survey published in 2024, former or current WSACS ambassadors, representative from WSES, ESAIC, ES

Eligibility criteria

Inclusion Criteria: Panellists will be identified based on either of the following criteria At least 5 years of clinical experience as a staff member in Anesthesiology, Surgery or Intensive Care Medicine with involvement in care of patients with postoperative complications Author of at least one publication (observational studies or randomised controlled trials) on intra-abdominal hypertension or abdominal compartment syndrome. For patients and public involvement Individuals who have either personally experienced IAH or ACS following surgery or ICU within the last 5 years or, primary caregivers of such patients will be recruited as patient care representatives. Proficiency in English is required. To mitigate potential bias, patient care representatives mustn't maintain a professional or advisory relationship with the steering committee or panellists. Co-authors from previous WSACS survey published in 2024, former or current WSACS ambassadors, representative from WSES, ESAIC, ESICM.

Exclusion Criteria:

  • None
05

Study design

Observational model
Cohort
Time perspective
Prospective
Enrollment
60 participants (estimated)
Target follow-up
6 Months
Patient registry
Yes

Groups and cohorts

  • Panelist

    Other: Delphi study

Interventions

  • OtherDelphi study

    structured interview via online survey

06

What researchers measure

Primary outcomes

  1. Level of consensus on definitions of intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS)

    Proportion of predefined definition statements for IAH and ACS reaching consensus among expert panellists, measured using a structured Delphi process. Consensus is defined a priori as ≥80% agreement on a 5-point Likert scale (ratings of 4-5 indicating agreement). Outcomes will include: Number and percentage of statements reaching consensus Median and interquartile range (IQR) of Likert scores per statement Stability of responses across Delphi rounds

    Time frame: 3-6 months

Secondary outcomes

  1. Level of consensus on pathophysiological concepts of IAH and ACS

    Proportion of predefined pathophysiological statements related to IAH and ACS reaching consensus among expert panellists using a Delphi process. Consensus is defined as ≥80% agreement on a 5-point Likert scale. Outcomes will include: Number and percentage of statements reaching consensus Median and IQR of Likert scores per statement Changes in agreement across Delphi rounds

    Time frame: 3-6 months

  2. Level of consensus on measurement methods for intra-abdominal pressure (IAP)

    Proportion of predefined statements regarding IAP measurement techniques reaching consensus among expert panellists using a Delphi process. Consensus is defined as ≥80% agreement on a 5-point Likert scale. Outcomes will include: Number and percentage of statements reaching consensus Median and IQR of Likert scores per statement Agreement trends across Delphi rounds

    Time frame: 3-6 months

07

Study locations

1 site
08

References and documents

Publications

  • Alhazzani W, Lewis K, Jaeschke R, Rochwerg B, Moller MH, Evans L, Wilson KC, Patel S, Coopersmith CM, Cecconi M, Guyatt G, Akl EA. Conflicts of interest disclosure forms and management in critical care clinical practice guidelines. Intensive Care Med. 2018 Oct;44(10):1691-1698. doi: 10.1007/s00134-018-5367-6. Epub 2018 Sep 27. PubMed 30264380 ↗
  • Traversy G, Barnieh L, Akl EA, Allan GM, Brouwers M, Ganache I, Grundy Q, Guyatt GH, Kelsall D, Leng G, Moore A, Persaud N, Schunemann HJ, Straus S, Thombs BD, Rodin R, Tonelli M. Managing conflicts of interest in the development of health guidelines. CMAJ. 2021 Jan 11;193(2):E49-E54. doi: 10.1503/cmaj.200651. No abstract available. PubMed 33431547 ↗
  • Schunemann HJ, Al-Ansary LA, Forland F, Kersten S, Komulainen J, Kopp IB, Macbeth F, Phillips SM, Robbins C, van der Wees P, Qaseem A; Board of Trustees of the Guidelines International Network. Guidelines International Network: Principles for Disclosure of Interests and Management of Conflicts in Guidelines. Ann Intern Med. 2015 Oct 6;163(7):548-53. doi: 10.7326/M14-1885. PubMed 26436619 ↗
  • Gattrell WT, Logullo P, van Zuuren EJ, Price A, Hughes EL, Blazey P, Winchester CC, Tovey D, Goldman K, Hungin AP, Harrison N. ACCORD (ACcurate COnsensus Reporting Document): A reporting guideline for consensus methods in biomedicine developed via a modified Delphi. PLoS Med. 2024 Jan 23;21(1):e1004326. doi: 10.1371/journal.pmed.1004326. eCollection 2024 Jan. PubMed 38261576 ↗
  • Nasa P, Jain R, Juneja D. Delphi methodology in healthcare research: How to decide its appropriateness. World J Methodol. 2021 Jul 20;11(4):116-129. doi: 10.5662/wjm.v11.i4.116. eCollection 2021 Jul 20. PubMed 34322364 ↗
  • Nasa P, Azoulay E, Khanna AK, Jain R, Gupta S, Javeri Y, Juneja D, Rangappa P, Sundararajan K, Alhazzani W, Antonelli M, Arabi YM, Bakker J, Brochard LJ, Deane AM, Du B, Einav S, Esteban A, Gajic O, Galvagno SM Jr, Guerin C, Jaber S, Khilnani GC, Koh Y, Lascarrou JB, Machado FR, Malbrain MLNG, Mancebo J, McCurdy MT, McGrath BA, Mehta S, Mekontso-Dessap A, Mer M, Nurok M, Park PK, Pelosi P, Peter JV, Phua J, Pilcher DV, Piquilloud L, Schellongowski P, Schultz MJ, Shankar-Hari M, Singh S, Sorbello M, Tiruvoipati R, Udy AA, Welte T, Myatra SN. Expert consensus statements for the management of COVID-19-related acute respiratory failure using a Delphi method. Crit Care. 2021 Mar 16;25(1):106. doi: 10.1186/s13054-021-03491-y. PubMed 33726819 ↗
  • Page MJ, McKenzie JE, Bossuyt PM, Boutron I, Hoffmann TC, Mulrow CD, Shamseer L, Tetzlaff JM, Akl EA, Brennan SE, Chou R, Glanville J, Grimshaw JM, Hrobjartsson A, Lalu MM, Li T, Loder EW, Mayo-Wilson E, McDonald S, McGuinness LA, Stewart LA, Thomas J, Tricco AC, Welch VA, Whiting P, Moher D. The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. BMJ. 2021 Mar 29;372:n71. doi: 10.1136/bmj.n71. PubMed 33782057 ↗
  • Nasa P, Wise RD, Smit M, Acosta S, D'Amours S, Beaubien-Souligny W, Bodnar Z, Coccolini F, Dangayach NS, Dabrowski W, Duchesne J, Ejike JC, Augustin G, De Keulenaer B, Kirkpatrick AW, Khanna AK, Kimball E, Koratala A, Lee RK, Leppaniemi A, Lerma EV, Marmolejo V, Meraz-Munoz A, Myatra SN, Niven D, Olvera C, Ordonez C, Petro C, Pereira BM, Ronco C, Regli A, Roberts DJ, Rola P, Rosen M, Shrestha GS, Sugrue M, Velez JCQ, Wald R, De Waele J, Reintam Blaser A, Malbrain MLNG. International cross-sectional survey on current and updated definitions of intra-abdominal hypertension and abdominal compartment syndrome. World J Emerg Surg. 2024 Nov 29;19(1):39. doi: 10.1186/s13017-024-00564-5. PubMed 39609850 ↗
  • Roberts DJ, Zygun DA, Kirkpatrick AW, Ball CG, Faris PD, Bobrovitz N, Robertson HL, Stelfox HT. A protocol for a scoping and qualitative study to identify and evaluate indications for damage control surgery and damage control interventions in civilian trauma patients. BMJ Open. 2014 Jul 7;4(7):e005634. doi: 10.1136/bmjopen-2014-005634. PubMed 25001397 ↗
  • Higa G, Friese R, O'Keeffe T, Wynne J, Bowlby P, Ziemba M, Latifi R, Kulvatunyou N, Rhee P. Damage control laparotomy: a vital tool once overused. J Trauma. 2010 Jul;69(1):53-9. doi: 10.1097/TA.0b013e3181e293b4. PubMed 20622578 ↗
  • Miller RS, Morris JA Jr, Diaz JJ Jr, Herring MB, May AK. Complications after 344 damage-control open celiotomies. J Trauma. 2005 Dec;59(6):1365-71; discussion 1371-4. doi: 10.1097/01.ta.0000196004.49422.af. PubMed 16394910 ↗
  • van Brunschot S, Schut AJ, Bouwense SA, Besselink MG, Bakker OJ, van Goor H, Hofker S, Gooszen HG, Boermeester MA, van Santvoort HC; Dutch Pancreatitis Study Group. Abdominal compartment syndrome in acute pancreatitis: a systematic review. Pancreas. 2014 Jul;43(5):665-74. doi: 10.1097/MPA.0000000000000108. PubMed 24921201 ↗
  • Strang SG, Van Lieshout EM, Breederveld RS, Van Waes OJ. A systematic review on intra-abdominal pressure in severely burned patients. Burns. 2014 Feb;40(1):9-16. doi: 10.1016/j.burns.2013.07.001. Epub 2013 Sep 17. PubMed 24050978 ↗
  • Karkos CD, Menexes GC, Patelis N, Kalogirou TE, Giagtzidis IT, Harkin DW. A systematic review and meta-analysis of abdominal compartment syndrome after endovascular repair of ruptured abdominal aortic aneurysms. J Vasc Surg. 2014 Mar;59(3):829-42. doi: 10.1016/j.jvs.2013.11.085. Epub 2014 Jan 16. PubMed 24439324 ↗
  • Malbrain ML, Chiumello D, Cesana BM, Reintam Blaser A, Starkopf J, Sugrue M, Pelosi P, Severgnini P, Hernandez G, Brienza N, Kirkpatrick AW, Schachtrupp A, Kempchen J, Estenssoro E, Vidal MG, De Laet I, De Keulenaer BL; WAKE-Up! Investigators. A systematic review and individual patient data meta-analysis on intra-abdominal hypertension in critically ill patients: the wake-up project. World initiative on Abdominal Hypertension Epidemiology, a Unifying Project (WAKE-Up!). Minerva Anestesiol. 2014 Mar;80(3):293-306. Epub 2013 Dec 12. PubMed 24603146 ↗
  • Moll V, Khanna AK, Kurz A, Huang J, Smit M, Swaminathan M, Minear S, Parr KG, Prabhakar A, Zhao M, Malbrain MLNG. Optimization of kidney function in cardiac surgery patients with intra-abdominal hypertension: expert opinion. Perioper Med (Lond). 2024 Jul 12;13(1):72. doi: 10.1186/s13741-024-00416-5. PubMed 38997752 ↗
  • Reintam Blaser A, Regli A, De Keulenaer B, Kimball EJ, Starkopf L, Davis WA, Greiffenstein P, Starkopf J; Incidence, Risk Factors, and Outcomes of Intra-Abdominal (IROI) Study Investigators. Incidence, Risk Factors, and Outcomes of Intra-Abdominal Hypertension in Critically Ill Patients-A Prospective Multicenter Study (IROI Study). Crit Care Med. 2019 Apr;47(4):535-542. doi: 10.1097/CCM.0000000000003623. PubMed 30608280 ↗
  • Regli A, Reintam Blaser A, De Keulenaer B, Starkopf J, Kimball E, Malbrain MLNG, Van Heerden PV, Davis WA; IROI Study Investigators; Palermo A, Dabrowski W, Siwicka-Gieroba D, Barud M, Grigoras I, Ristescu AI, Blejusca A, Tamme K, Maddison L, Kirsimagi U, Litvin A, Kazlova A, Filatau A, Pracca F, Sosa G, Santos MD, Kirov M, Smetkin A, Ilyina Y, Gilsdorf D, Ordonez CA, Caicedo Y, Greiffenstein P, Morgan MM, Bodnar Z, Tidrenczel E, Oliveira G, Albuquerque A, Pereira BM. Intra-abdominal hypertension and hypoxic respiratory failure together predict adverse outcome - A sub-analysis of a prospective cohort. J Crit Care. 2021 Aug;64:165-172. doi: 10.1016/j.jcrc.2021.04.009. Epub 2021 Apr 17. PubMed 33906106 ↗
  • Strang SG, Van Lieshout EM, Van Waes OJ, Verhofstad MH. Prevalence and mortality of abdominal compartment syndrome in severely injured patients: A systematic review. J Trauma Acute Care Surg. 2016 Sep;81(3):585-92. doi: 10.1097/TA.0000000000001133. PubMed 27398983 ↗
  • Kirkpatrick AW, Roberts DJ, De Waele J, Jaeschke R, Malbrain ML, De Keulenaer B, Duchesne J, Bjorck M, Leppaniemi A, Ejike JC, Sugrue M, Cheatham M, Ivatury R, Ball CG, Reintam Blaser A, Regli A, Balogh ZJ, D'Amours S, Debergh D, Kaplan M, Kimball E, Olvera C; Pediatric Guidelines Sub-Committee for the World Society of the Abdominal Compartment Syndrome. 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. doi: 10.1007/s00134-013-2906-z. Epub 2013 May 15. PubMed 23673399 ↗
  • De Waele JJ, Cheatham ML, Malbrain ML, Kirkpatrick AW, Sugrue M, Balogh Z, Ivatury R, De Keulenaer B, Kimball EJ. Recommendations for research from the International Conference of Experts on Intra-abdominal Hypertension and Abdominal Compartment Syndrome. Acta Clin Belg. 2009 May-Jun;64(3):203-9. doi: 10.1179/acb.2009.036. PubMed 19670559 ↗
  • Cheatham ML. Nonoperative management of intraabdominal hypertension and abdominal compartment syndrome. World J Surg. 2009 Jun;33(6):1116-22. doi: 10.1007/s00268-009-0003-9. PubMed 19363690 ↗
  • Cheatham ML, Malbrain ML, Kirkpatrick A, Sugrue M, Parr M, De Waele J, Balogh Z, Leppaniemi A, Olvera C, Ivatury R, D'Amours S, Wendon J, Hillman K, Wilmer A. Results from the International Conference of Experts on Intra-abdominal Hypertension and Abdominal Compartment Syndrome. II. Recommendations. Intensive Care Med. 2007 Jun;33(6):951-62. doi: 10.1007/s00134-007-0592-4. Epub 2007 Mar 22. PubMed 17377769 ↗
  • Malbrain ML, De Laet I, Cheatham M. Consensus conference definitions and recommendations on intra-abdominal hypertension (iah) and the abdominal compartment syndrome (acs) - the long road to the final publications, how did we get there? Acta Clin Belg. 2007;62 Suppl 1:44-59. doi: 10.1179/acb.2007.62.s1.007. PubMed 24881700 ↗
  • Malbrain ML, Cheatham ML, Kirkpatrick A, Sugrue M, Parr M, De Waele J, Balogh Z, Leppaniemi A, Olvera C, Ivatury R, D'Amours S, Wendon J, Hillman K, Johansson K, Kolkman K, Wilmer A. Results from the International Conference of Experts on Intra-abdominal Hypertension and Abdominal Compartment Syndrome. I. Definitions. Intensive Care Med. 2006 Nov;32(11):1722-32. doi: 10.1007/s00134-006-0349-5. Epub 2006 Sep 12. PubMed 16967294 ↗
  • Murphy PB, Parry NG, Sela N, Leslie K, Vogt K, Ball I. Intra-Abdominal Hypertension Is More Common Than Previously Thought: A Prospective Study in a Mixed Medical-Surgical ICU. Crit Care Med. 2018 Jun;46(6):958-964. doi: 10.1097/CCM.0000000000003122. PubMed 29578878 ↗
  • Blaser AR, Sarapuu S, Tamme K, Starkopf J. Expanded measurements of intra-abdominal pressure do not increase the detection rate of intra-abdominal hypertension: a single-center observational study. Crit Care Med. 2014 Feb;42(2):378-86. doi: 10.1097/CCM.0b013e3182a6459b. PubMed 24145841 ↗

Related links

Individual participant data

Plan to share: No — The IPD is available to investigators and can be shared with appropriate requests.

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on May 4, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT07563842
Lead sponsor
Medical University of Lublin
Responsible party
Manu Malbrain (Professor Critical Care Research, Medical University of Lublin) — Principal investigator
First posted
May 4, 2026
Start date
Oct 13, 2025
Primary completion
Jul 31, 2026 (estimated)
Completion
Jul 31, 2026 (estimated)
Last update
May 4, 2026

Study contacts

Prashant Nasa, MD
principal investigator · The Royal Wolverhampton NHS Trust Wolverhampton, UK

Oversight

Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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