Abdominal compartment syndrome (ACS) occurs when the

abdomen The abdomen (colloquially called the gut, belly, tummy, midriff, tucky, or stomach) is the front part of the torso between the thorax (chest) and pelvis in humans and in other vertebrates. The area occupied by the abdomen is called the abdominal ...

becomes subject to increased pressure reaching past the point of intra-abdominal hypertension (IAH). ACS is present when intra-abdominal pressure rises and is sustained at > 20 mmHg and there is new organ dysfunction or failure. ACS is classified into three groups: Primary, secondary and recurrent ACS. It is not a disease and as such it occurs in conjunction with many disease processes, either due to the primary illness or in association with treatment interventions. Specific cause of abdominal compartment syndrome is not known, although some causes can be

sepsis Sepsis is a potentially life-threatening condition that arises when the body's response to infection causes injury to its own tissues and organs. This initial stage of sepsis is followed by suppression of the immune system. Common signs and s ...

and severe abdominal trauma. Increasing pressure reduces blood flow to abdominal organs and impairs

pulmonary The lungs are the primary organs of the respiratory system in many animals, including humans. In mammals and most other tetrapods, two lungs are located near the backbone on either side of the heart. Their function in the respiratory syste ...

cardiovascular In vertebrates, the circulatory system is a system of organs that includes the heart, blood vessels, and blood which is circulated throughout the body. It includes the cardiovascular system, or vascular system, that consists of the heart a ...

renal In humans, the kidneys are two reddish-brown bean-shaped blood-filtering organs that are a multilobar, multipapillary form of mammalian kidneys, usually without signs of external lobulation. They are located on the left and right in the retrop ...

, and gastro-intestinal (GI) function, causing

obstructive shock Obstructive shock is one of the four types of shock, caused by a physical obstruction in the flow of blood. Obstruction can occur at the level of the great vessels or the heart itself. Causes include pulmonary embolism, cardiac tamponade, and ten ...

multiple organ dysfunction syndrome Multiple organ dysfunction syndrome (MODS) is altered organ function in an acutely ill patient requiring immediate medical intervention. There are different stages of organ dysfunction for certain different organs, both in acute and in chronic ...

and death.

Causes

* Peritoneal tissue edema secondary to diffuse peritonitis,

abdominal trauma Abdominal trauma is an injury to the abdomen. Signs and symptoms include abdominal pain, tenderness (medicine), tenderness, rigidity, and bruise, bruising of the external abdomen. Complications may include blood loss and infection. Diagnosis ma ...

* Fluid therapy due to massive volume resuscitation * Retroperitoneal hematoma secondary to trauma and

aortic rupture Aortic rupture is the breakage of all walls of the aorta, the largest artery in the body. Aortic rupture is a rare, extremely dangerous condition that is considered a medical emergency. The most common cause is an abdominal aortic aneurysm that ...

* Peritoneal trauma secondary to emergency abdominal operations *

Reperfusion injury Reperfusion injury, sometimes called ischemia-reperfusion injury (IRI) or reoxygenation injury, is the tissue damage caused when blood supply returns to tissue ('' re-'' + ''perfusion'') after a period of ischemia or lack of oxygen (anoxia or hy ...

following bowel ischemia due to any cause * Retroperitoneal and mesenteric inflammatory edema secondary to acute

pancreatitis Pancreatitis is a condition characterized by inflammation of the pancreas. The pancreas is a large organ behind the stomach that produces digestive enzymes and a number of hormone A hormone (from the Ancient Greek, Greek participle , "se ...

* Ileus and bowel obstruction * Intra-abdominal masses of any cause * Abdominal packing for control of bleeding * Closure of the abdomen under undue tension *

Ascites Ascites (; , meaning "bag" or "sac") is the abnormal build-up of fluid in the abdomen. Technically, it is more than 25 ml of fluid in the peritoneal cavity, although volumes greater than one liter may occur. Symptoms may include increased abdo ...

(intra-abdominal fluid accumulation) * Acute pancreatitis with abscesses formation

Pathophysiology

Abdominal compartment syndrome occurs when tissue fluid within the

peritoneal The peritoneum is the serous membrane forming the lining of the abdominal cavity or coelom in amniotes and some invertebrates, such as annelids. It covers most of the intra-abdominal (or coelomic) organs, and is composed of a layer of mesotheli ...

and

retroperitoneal space The retroperitoneal space (retroperitoneum) is the spatium, anatomical space (sometimes a potential space) behind (''retro'') the peritoneum. It has no specific delineating anatomical structures. Organs are retroperitoneal if they have peritoneum ...

(either

edema Edema (American English), also spelled oedema (British English), and also known as fluid retention, swelling, dropsy and hydropsy, is the build-up of fluid in the body's tissue (biology), tissue. Most commonly, the legs or arms are affected. S ...

, retroperitoneal blood or free fluid in the abdomen) accumulates in such large volumes that the abdominal wall compliance threshold is crossed and the abdomen can no longer stretch. Once the abdominal wall can no longer expand, any further fluid leaking into the tissue results in fairly rapid rises in the pressure within the closed space. Initially this increase in pressure does not cause organ failure but does prevent organs from working properly – this is called intra-abdominal hypertension and is defined as a pressure over 12 mmHg in adults. ACS is defined by a sustained IAP(intra-abdominal pressure) above 20 mmHg with new-onset or progressive organ failure. Severe organ dysfunctionent syndrome. These pressure measurements are relative. Small children get into trouble and develop compartment syndromes at much lower pressures while young previously healthy athletic individuals may tolerate an abdominal pressure of 20 mmHg very well. The underlying cause of the disease process is capillary permeability caused by the

systemic inflammatory response syndrome In immunology, systemic inflammatory response syndrome (SIRS) is an inflammation, inflammatory state affecting the whole body. It is the body's Immune response, response to an infectious or noninfectious Insult (medical), insult. Although the ...

(SIRS) that occurs in every critically ill patient. SIRS leads to leakage of fluid out of the capillary beds into the interstitial space in the entire body with a profound amount of this fluid leaking into the gut wall, mesentery and retroperitoneal tissue. Abdominal compartment syndrome follows a destructive pathway similar to

compartment syndrome Compartment syndrome is a serious medical condition in which increased pressure within a Fascial compartment, body compartment compromises blood flow and tissue function, potentially leading to permanent damage if not promptly treated. There are ...

of the extremities. When increased compression occurs in such a hollow space, organs will begin to collapse under the pressure. As the pressure increases and reaches a point where the

can no longer be distended it starts to affect the cardiovascular and pulmonary systems. When abdominal compartment syndrome reaches this point without surgery and help of a silo the patient will most likely die. There is a high mortality rate associated with abdominal compartment syndrome.

Diagnosis

Abdominal compartment syndrome is defined as an intra-abdominal pressure above 20 mmHg with evidence of organ failure. Abdominal compartment syndrome develops when the intra-abdominal pressure rapidly reaches certain pathological values, within several hours (intra-abdominal hypertension is observed), and lasts for 6 or more hours. The key to recognizing abdominal compartment syndrome is the demonstration of elevated intra-abdominal pressure which is performed most often via the urinary bladder, and it is considered to be the "

gold standard A gold standard is a backed currency, monetary system in which the standard economics, economic unit of account is based on a fixed quantity of gold. The gold standard was the basis for the international monetary system from the 1870s to the ...

". The increased intra-abdominal pressure leads to compression of the renal veins, which, in turn, to an oliguria that is unresponsive to fluid resuscitation. Diagnosis should be based on clinical findings in conjunction with a measurement of a bladder pressure. The trend of the bladder pressure may be more helpful than the absolute number. Multiorgan failure includes damage to the cardiac, pulmonary, renal, neurological, gastrointestinal, abdominal wall, and ophthalmic systems. The gut is the most sensitive to intra-abdominal hypertension, and it develops evidence of end-organ damage before alterations are observed in other systems. In a recent systematic review, Holodinsky et al. described 25 risk factors associated with IAH (intra-abdominal hypertension) and 16 with ACS (abdominal compartment syndrome). These can be roughly categorized in three categories, which may be more helpful at the bedside to identify patients at risk (Table 1). Especially noteworthy is the potential role of fluid resuscitation in the development of IAH and ACS. Recognizing the pivotal role of fluid resuscitation in the pathogenesis of IAH and ACS supplies the clinician with a target for preventive measures. Large volume resuscitation with crystalloids should be avoided in patients with or at risk of ACS.

Treatment

Operative decompression

The mortality rate associated with abdominal compartment syndrome is significant, ranging between 60% and 70%. The poor outcome relates not only to abdominal compartment syndrome itself but also to concomitant injury and hemorrhagic shock. The surgical decompression of the abdomen remains the treatment of choice of abdominal compartment syndrome; this usually improves the organ changes and is followed by one of the temporary abdominal closure techniques in order to prevent secondary intra-abdominal hypertension. Surgical decompression can be achieved by opening the abdominal wall and abdominal fascia anterior in order to physically create more space for the abdominal viscera. Once opened, the fascia can be bridged for support and to prevent loss of domain by a variety of medical devices ( Bogota bag, artificial bur, and vacuum devices using negative pressure wound therapy).

References

External links

openabdomen.org

wsacs.org
{{Portalbar, Medicine Syndromes affecting the gastrointestinal tract