WSACS Algorithms
The primary mission of the WSACS is to promote research, foster education, and improve the survival of patients with intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) by sharing information on effective management strategies. The following instructional materials are provided to aid in the education of physicians, nurses, respiratory therapists, and other healthcare providers.
The WSACS has created three algorithms detailing the current state-of-the-art diagnosis and management of IAH / ACS.
The IAH/ACS Management, and IAH/ACS Medical Management algorithms may be freely downloaded for educational and patient care purposes. Reproduction of the algorithms in either print or electronic publications requires copyright permission from the WSACS. Please contact the WSACS Executive Committee to secure permission for reproduction.
 |
1. The IAH/ACS Management Algorithm describes an evidence-based approach to the management of patients with elevated IAP and organ dysfunction. Download and print this PDF file to ensure that your management follows the WSACS Consensus Recommendations. Download IAH/ACS Management Algorithm |
 |
2. The IAH/ACS Medical Management Algorithm describes an evidence-based approach to the management of patients with elevated IAP and organ dysfunction. Download and print this PDF file to ensure that your management follows the WSACS Consensus Recommendations. |
WSACS Consensus Guidelines Summary
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. |
Recommendations
| 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). |
WSACS Consensus Definitions and Recommendations
The primary mission of the WSACS is to promote research, foster education, and improve the survival of patients with intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) by sharing information on effective management strategies. The following instructional materials are provided to aid in the education of physicians, nurses, respiratory therapists, and other healthcare providers.
The WSACS has recently updated the two consensus documents from 2006 and 2007 detailing the current state-of-the-art diagnosis and management of IAH / ACS. The updated document can be downloaded from the Intensive Care Medicine website:
WSACS 2013 updated IAH and ACS consensus definitions and clinical practice guidelines