Abdominal compartment syndrome is a complex of pathological changes that occur against the background of a persistent increase in intra-abdominal pressure (IAP) and cause the development of multiple organ failure. It is observed after operations, with severe injuries and diseases of the abdominal cavity, retroperitoneal space, less often – with extraabdominal pathology. It is manifested by cardiac, renal, respiratory insufficiency, liver and gastrointestinal disorders. The basis of early diagnosis is repeated measurements of IAP, additionally data from instrumental and laboratory studies are used. Treatment – urgent surgical decompression, infusion therapy, ventilator.
Abdominal compartment syndrome (ACS) is a formidable complication that occurs in severe diseases, traumatic injuries and surgical interventions. The first reports of the negative effect of increased intraabdominal pressure on the condition of patients appeared at the end of the XIX century, but the pathogenesis of ACS and the significance of the syndrome as a cause of mortality were established only in the 80s of the last century.
According to various data, pathology is diagnosed in 2-30% of patients operated on for abdominal injuries. Among patients who are in critical condition at the time of admission and in need of resuscitation, a significant increase in intra-abdominal pressure is detected in more than 50% of cases, clinical signs of ACS are detected in about 4% of cases. Without treatment, the mortality rate is 100%.
Causes of abdominal compartment syndrome
The abdominal cavity is a closed space limited by bone and soft tissue structures. Normally, the pressure in it is close to zero. With obesity and during pregnancy, this indicator increases, but due to the slow development of changes, the patient’s body gradually adapts to this condition. With a rapid increase in IAP, the patient’s body does not have time to adapt to changes, which entails violations of the activities of various organs. The probability of AKS formation increases in the presence of the following factors:
- Reducing the extensibility of the abdominal wall. It is found with extensive rough scars, intense abdominal pain, muscle spasm, after the plastic surgery of large hernias, with pleuropneumonia, during the ventilator, especially against the background of incorrect settings of artificial respiration parameters.
- An increase in the volume of the contents of the abdominal cavity. It is noted with large neoplasms, intestinal obstruction, large hematomas in the retroperitoneal tissue, abdominal aortic aneurysms.
- Accumulation of liquid or gas. The cause of fluid accumulation can be peritonitis, hemoperitoneum in injuries, ascites in tumors, cirrhosis of the liver and other diseases. Significant pneumoperitoneum usually occurs with thoracoabdominal injuries with a violation of the integrity of the lung and diaphragm. The injection of air into the abdominal cavity during endoscopic interventions may play a certain role.
- Capillary leakage syndrome. It is characterized by an increase in the permeability of capillaries and the release of fluid into the tissues from the vascular bed. It is observed with sepsis, extensive burns, acidosis, coagulopathy, hypothermia, massive transfusion of blood and blood substitutes, solutions for intravenous infusions.
The heterogeneity of provoking factors is the cause of the compartment syndrome in a wide range of diseases and conditions, including those not related to abdominal pathology. The most common causes of ACS are severe abdominal injuries, intra-abdominal bleeding of various genesis, liver transplantation, peritonitis, acute destructive pancreatitis, multiple fractures of the pelvic bones, extensive burns, infusion therapy of shock conditions. Less often, the syndrome is observed with intestinal obstruction, after hernia repair, during peritoneal dialysis.
With an increase in intraabdominal pressure, blood flow in the abdominal cavity is disrupted, this provokes damage to the gastric and intestinal mucosa up to the formation of necrosis sites, perforation of the hollow organ and the development of peritonitis. Circulatory disorders in the vessels of the liver cause necrosis of more than 10% of hepatocytes and corresponding changes in liver samples.
The barrier function of the intestine suffers, which is manifested by contact, lymphogenic and hematogenic spread of bacterial agents. The probability of infectious complications increases. Compression of the operated organs potentiates the failure of anastomoses.
The diaphragm shifts upwards, this causes an increase in pressure in the pleural cavity and air exchange disorders. Respiratory, and subsequently metabolic acidosis occurs. Respiratory distress syndrome is formed. The supply of oxygen to the myocardium is disrupted. Due to compression of large venous trunks, central venous pressure increases, venous return to the heart decreases, intracranial hypertension develops due to difficulty in blood outflow from the brain.
Due to compression of the kidneys, blood circulation in the renal parenchyma worsens, glomerular filtration is disrupted, necrosis foci are formed. Damage to the renal tissue provokes an increase in the content of hormones involved in the regulation of kidney function. Some patients have acute renal failure with oliguria or anuria.
A steady increase in IBD is called intra-abdominal hypertension. To determine the tactics of treatment, the Birch classification with co-authors is used, in which four degrees of this condition are distinguished: 12-15, 16-20, 21-25 and more than 25 mmHg. ACS is associated with intraabdominal pressure of 20 mmHg or more, the exact indicators at which life-threatening changes occur have not yet been established. Taking into account the etiological factor, there are three variants of abdominal compartment syndrome:
- Primary. It is provoked by pathological processes in the abdominal cavity and retroperitoneal space. It is found in injuries, peritonitis, pancreatitis, rupture of an abdominal aortic aneurysm, extensive abdominal operations, large retroperitoneal hematomas.
- Secondary. It is formed during extraabdominal pathological processes. It is diagnosed with severe burns, sepsis, massive infusions.
- Tertiary. It is characterized by the recurrence of symptoms in patients who have undergone primary or secondary variants of the syndrome. The reason is usually a change in factors affecting the IAP, for example, suturing of the laparostomy. Mortality rates are higher than in other forms.
Symptoms of abdominal compartment syndrome
Clinical manifestations of pathology are nonspecific, include disorders on the part of various organs and systems, indicating the development and progression of multiple organ failure. Data on the first symptoms vary. Some researchers indicate that the syndrome manifests tension of the abdominal muscles, an increase in abdominal volume, which are combined with respiratory disorders, a decrease in diuresis. Other experts believe that respiratory disorders and oliguria are ahead of abdominal symptoms.
Breathing is frequent, shallow. Oliguria is replaced by anuria. There is a rapid heartbeat, a decrease in blood pressure with unchanged or increased central venous pressure (CVP). The phenomena of respiratory, cardiac and renal insufficiency are rapidly increasing, with independent breathing, it becomes necessary to transfer the patient to a ventilator, stimulation of diuresis is required, but the use of diuretics often does not provide the desired result. In the absence of decompression, death occurs from a progressive violation of the activity of vital organs.
Typical complications of the compartment syndrome that arose after surgical interventions are the failure of sutures and anastomoses, suppuration of wounds. The probability of formation of intra-abdominal abscesses, peritonitis, sepsis increases. After decompression laparotomy, hernias and intestinal fistulas form in 90% of patients, and multiple ligature fistulas form in 22%.
Due to impaired lung function, the risk of pneumonia increases. Some patients with acute kidney failure in the long term develop chronic renal failure. The duration of treatment of major diseases is increasing, and worse functional outcomes are noted for injuries.
Due to the non-specific manifestations and other possible causes of multiple organ failure, the diagnosis of this condition on the basis of clinical symptoms causes significant difficulties. Taking into account the severity of the pathology and its threat to the patient’s life, periodic preventive measurement of IAP in persons at risk of developing compartment syndrome is considered the best option.
In the case of laparostomy, abdominal drainage, peritoneal dialysis or laparoscopy, direct measurements of the indicator are possible, but due to the complexity and invasiveness, these methods are rarely used. The following diagnostic procedures are commonly used:
- Measurement of pressure in the bladder. Is the most common study. It is performed by catheterization after urine excretion and administration of 20-25 ml of warm solution.
- Other options for measuring IAP. To assess the indicator, the stomach (through a nasogastric probe) and the inferior vena cava are used. The measurement indicators may differ somewhat from the actual IAP, however, correctly repeated procedures allow us to obtain a fairly accurate picture of changes in intra-abdominal pressure.
- Laboratory tests. When analyzing arterial blood gases, acute respiratory alkalosis is determined. The blood shows an increase in the level of lactate, urea, creatinine, alanine aminotransferase, alkaline phosphatase, and a decrease in blood pH. In urine tests, proteinuria, erythrocyturia, and cylindruria are detected.
- Chest X-ray. The radiographs show the rise of the diaphragm domes.
Treatment of abdominal compartment syndrome
Surgical decompression is considered to be the main method of treating ACS, but the indications for intervention have not yet been precisely determined. In clinical practice, an algorithm is often used, according to which, with 1 and 2 degrees of intraabdominal hypertension, monitoring and correction of infusion therapy is recommended, with 3 – decompressive laparotomy against the background of intensive therapy, with 4 – urgent surgical decompression and resuscitation measures.
In the presence of ascites at the initial stage, it is possible to perform abdominal puncture, laparocentesis or laparoscopy with subsequent drainage. Surgical decompression is performed in the operating room or intensive care unit. A transverse or median incision is used. In the future, the management is carried out by the “open belly” method. With the normalization of IAP, the absence of edema of internal organs and surrounding tissues, the wound is sutured for 1-8 days. In other cases, delayed closure of the laparostomy is performed. To reduce the risk of hernias, mesh grafts are installed.
Operative measures are carried out against the background of monitoring vital signs, ventilation, stimulation of diuresis, correction of metabolic disorders, prevention of cardiovascular collapse due to a decrease in peripheral vascular resistance, prevention of cardiac disorders caused by the intake of lactate and potassium into the bloodstream after elimination of ischemia.
Prognosis and prevention
The prognosis for abdominal compartment syndrome is determined by the timeliness of therapeutic measures. With operative decompression during the first 6 hours after the appearance of signs of ACS (before the formation of a detailed picture of multiple organ failure), the survival rate is 80%. With late interventions, 43-65% of patients die. In the absence of decompression measures, the mortality rate reaches 100%.
Prevention includes medical alertness at admission of patients at risk of ACS formation, regular measurement of IOP, adequate respiratory support, correct infusion therapy. Some authors suggest not to suture aponeurosis in severe abdominal injuries and other pathologies that provoke ACS, but this measure is not always effective.