WSACS Consensus Guidelines Summary

Education

Date	April 7, 2021
Modified	April 7, 2021
Author	WSACS

The following tables summarize the WSACS consensus definitions and recommendations statements as published in Intensive Care Medicine. Further details and the evidence-based medicine support for these guidelines may be found in the published douments. The evidentiary grading utilizes the GRADE system. Details of the GRADE approach can be found at the GRADE Working Group.

Definitions

Definition 1	Intra-abdominal pressure (IAP) is the pressure concealed within the abdominal cavity.
Definition 2	Abdominal perfusion pressure (APP) = mean arterial pressure (MAP) – IAP.
Definition 3	Filtration Gradient (FG) = glomerular filtration pressure (GFP) – proximal tubular pressure (PTP) = MAP – 2 * IAP.
Definition 4	IAP should be expressed in mmHg and measured at end-expiration in the complete supine position after ensuring that abdominal muscle contractions are absent and with the transducer zeroed at the level of the mid-axillary line.
Definition 5	The reference standard for intermittent IAP measurement is via the bladder with a maximal instillation volume of 25 mL of sterile saline.
Definition 6	Normal IAP is approximately 5-7 mmHg in critically ill adults.
Definition 7	IAH is defined by a sustained or repeated pathologic elevation of IAP >= 12 mmHg.
Definition 8	IAH is graded as follows: Grade I: IAP 12-15 mmHg, Grade II: IAP 16-20 mmHg, Grade III: IAP 21- 25 mmHg, Grade IV: IAP > 25 mmHg
Definition 9	Abdominal compartment syndrome (ACS) is defined as a sustained IAP > 20 mmHg (with or without an APP < 60 mmHg) that is associated with new organ dysfunction / failure.
Definition 10	Primary ACS is a condition associated with injury or disease in the abdomino-pelvic region that frequently requires early surgical or interventional radiological intervention.
Definition 11	Secondary ACS refers to conditions that do not originate from the abdomino-pelvic region.
Definition 12	Recurrent ACS refers to the condition in which ACS redevelops following previous surgical or medical treatment of primary or secondary ACS.

Recommen-dations

Risk Factors for IAH / ACS	Patients should be screened for IAH / ACS risk factors upon ICU admission and in the presence of new or progressive organ failure (GRADE 1B).
IAP Measurement	If two or more risk factors for IAH / ACS are present, a baseline IAP measurement should be obtained (GRADE 1B). If IAH is present, serial IAP measurements should be performed throughout the patient?s critical illness (GRADE 1C). Studies should adopt the standardized IAP measurement method recommended by the consensus definitions OR provide sufficient detail of the technique utilized to allow accurate interpretation of the IAP data presented (GRADE 2C).
Abdominal Perfusion Pressure	APP should be maintained above 50-60 mmHg in patients with IAH / ACS (GRADE 1C).
Sedation & Analgesia	Insufficient data exist to make recommendations at this time.
Neuromuscular Blockade	A brief trial of neuromuscular blockade may be considered in selected patients with mild to moderate IAH while other interventions are performed to reduce IAP (GRADE 2C).
Body Positioning	The potential contribution of body position in elevating IAP should be considered in patients with moderate to severe IAH or ACS (GRADE 2C).
Gastric/colonic Decompression	Insufficient data exist to make recommendations at this time.
Fluid Resuscitation	Fluid resuscitation volume should be carefully monitored to avoid over-resuscitation in patients at risk for IAH / ACS (GRADE 1B). Hypertonic crystalloid and colloid-based resuscitation should be considered in patients with IAH to decrease the progression to secondary ACS (GRADE 1C).
Diuretics / Hemofiltration	Insufficient data exist to make recommendations at this time.
Percutaneous Decompression	Percutaneous catheter decompression should be considered in patients with intraperitoneal fluid, abscess, or blood who demonstrate symptomatic IAH or ACS (GRADE 2C).
Abdominal Decompression	Surgical decompression should be performed in patients with ACS that is refractory to other treatment options (GRADE 1B). Presumptive decompression should be considered at the time of laparotomy in patients who demonstrate multiple risk factors for IAH / ACS (GRADE 1C).
Definitive Abdominal Closure	Insufficient data exist to make recommendations at this time.
Future Research	Incidence and prevalence estimates of IAH / ACS should be based upon the consensus definitions (GRADE 1C). Mean, median, and maximal IAP values should be provided both on admission and during the study period (GRADE 2C).