II. Epidemiology
- Uncommon
III. Pathophysiology
- Abdominal Compartment Syndrome occurs when intraabdominal pressure (IAP) >20-25 mmHg
- Normal intraabdominal pressure is typically 5-7 mmHg
- Intraabdominal Hypertension is 12 mmHg or greater
- Pregnant patients and the morbidly obese may have intraabdominal pressures 10-15 mmHg
- Abdominal perfusion pressure (APP) = pMeanArterial - pIntraAbdominal
- where pMeanArterial is Mean arterial pressure (MAP)
- where pIntraAbdominal is Intraabdominal Pressure
- Abdominal perfusion pressure (APP) decreases when intraabdominal pressures rapidly rise
- Best outcomes occur when APP is maintained >60 mmHg
- Reduced abdominal perfusion pressure is associated with multiple extraabdominal adverse effects
- Decreased cardiac venous return
- Decreased renal perfusion
- Decreased diaphragm excursion
- Abdominal Compartment Syndrome is a diagnosis at the far end of the spectrum of decreased perfusion pressure
- Occurs when APP drops below adequate level (e.g. <60 mmHg)
IV. Causes
- Abdominal Trauma or hemoperitoneum
- Acute Pancreatitis
- Massive fluid third spacing (e.g. severe Burn Injury, multi-system Trauma, fluid Resuscitation)
- Massive Ascites
- Rapidly increasing free air
- Rapid bowel distention
- Retroperitoneal source (ruptured AAA, Pelvic Fracture with Hemorrhage)
V. Symptoms
- Malaise
- Dyspnea
- Abdominal Pain
- Abdominal Bloating
VI. Signs
-
General
- Critically ill appearing patient
-
Abdomen
- Marked, firm, tense Abdominal Distention
- Mesenteric Ischemia
- Cardiopulmonary findings
- Hypotension, shock state (reduced Preload from IVC compression)
- Dyspnea and Hypoxia (reduced diaphragm excursion)
- Tachycardia
- Peripheral Edema
- Renal findings
- Oliguria and Renal Failure (decreased renal perfusion)
VII. Diagnosis: Abdominal Compartment Pressure Measurement
- Insert Foley Catheter
- Drain the catheter and clamp the tubing
- Instill 25-60 cc sterile water into side port and clamp
- Pressure measurement
- Technique
- Patient lies supine
- Keep head and body in same position each time a measurement is obtained
- Perform measurement at end expiration
- Ensure Abdomen as relaxed as possible (adequate sedation and analgesia)
- Option 1
- Connect Foley Catheter to pressure transducer (via 18 gauge needle or needleless system)
- Connect pressure transducer to Arterial Line, zeroing to the level of the Bladder
- Unclamp foley after obtaining measurement
- Option 2
- Raise the Foley Catheter end vertically and unclamp
- Measure the distance (in cm) from Bladder level to the level of rising water in the catheter
- Each 1.36 cm H2O is equivalent to 1 mmHg (positive if >27.2 to 34 cm H2O)
- Interpretation
- Significant pressure consistent with Abdominal Compartment Syndrome: >=20 mmHg
- Compartment Pressure >=12 mmHg should be rechecked every 4 to 6 hours
- Compartment Pressure <10mmHg is unlikely to be Abdominal Compartment Syndrome
- Compartment Pressure may be inaccurate in neurogenic Bladder
- Technique
VIII. Management
- Emergent surgical decompression with exploratory laparotomy
-
General
- Avoid excessive fluid infusions which may worsen fluid third spacing
- Use adequate Analgesics and sedation (may help relax the abdominal wall)
- Ventilated patients will have falsely elevated plateau pressures
- Increase allowed Ventilator pressures to ensure adequate Tidal Volume
- Position in reverse Trendelenburg
- Temporizing measures while awaiting surgical management
- Nasogastric Tube
- Foley Catheter
- Large volume Paracentesis of Ascites may be attempted if significant surgery delay
- Escharotomy in a burn patient when indicated
- Veno-venous hemofiltration Dialysis
IX. Prognosis
- Mortality: >60%
X. References
- Jhun and Roepke in Herbert (2016) EM:Rap 16(1): 16-7
- Gestring in Sanfrey and Bulger (2015) UpToDate, Wolters-Kluwer, accessed 1/6/2016
- Swaminathan and Hope in Herbert (2019) EM:Rap 19(2): 3
- Weingart and Swaminathan (2023) Critical Care Mailbag: Abdominal Compartment Syndrome, EM:Rap, accessed 8/1/2023