Beneath the Surface: Navigating Abdominal Compartment Syndrome and the Open Belly Dilemma

Beneath the Surface: Navigating Abdominal Compartment Syndrome and the Open Belly Dilemma

First described in the late 1800s, abdominal compartment syndrome (ACS) is a potentially life-threatening condition that affects critically ill patients. It was not long ago that patients with ACS due to trauma or intra-abdominal emergencies were cared for only in surgical/trauma units. But critical care processes have surely changed! Many types of units see patients with ACS and those who require an open abdomen to manage this condition.

Intra-abdominal hypertension (IAH) develops in the abdominal cavity and may ultimately lead to ACS. The abdominal cavity/intra-abdominal space is a confined location. When bleeding, tissue edema or other fluid collects in this space, it cannot get out. ACS occurs when bleeding or swelling causes dangerously increased pressure in the abdomen. If this pressure is not released, it can continue to increase. With a continuing increase, other organ systems can be negatively affected by the pressure, compressing the renal circulation and venous return from the inferior vena cava, and reducing lung volume due to decreased capacity in the thoracic cavity.

The result is the potential for acute kidney injury (AKI), decreased cardiac output and impaired ventilation and oxygenation. Signs of these complications may include a tense, distended abdomen, decreased urine output and hypotension.

Following is a case study to illustrate how we identified and treated a patient with IAH and ACS.

Case Study

An adult patient with gallstone-induced severe acute pancreatitis was admitted to the ICU from the emergency department. The patient, who required aggressive fluid resuscitation to support hemodynamic status, had received 19 liters of crystalloid within the first 24 hours of admission. We began measuring compartment (bladder) pressures due to the ongoing fluid requirements and our assessments that the patient’s abdominal girth appeared to be increasing. Initial hourly pressures ranged from 15 to 17 mm Hg. Here’s how we identified IAH and made sure to accurately measure that pressure:

Intra-abdominal Hypertension Grading

IAH is measured and graded by severity:

• IAH is defined as a persistent IAP greater than 12 mm Hg.
• IAH should be measured at end-expiration and when the patient is supine.
• IAH is graded according to the IAP level:
• Grade I 12-15 mm Hg
• Grade II 16-20 mm Hg
• Grade III 21-25 mm Hg
• Grade IV greater than 25 mm Hg
• Acute IAH is a sustained elevation of IAP.
• Acute IAH can progress to ACS, which develops when organ failure occurs due to an increase in IAP.

As the condition progresses, critical care nurses need to be concerned, because the mortality rate of increasing IAP is associated with the grade of IAH. If ACS develops, it leads to a mortality risk of 75%-90%. IAP higher than 20 mm Hg is associated with organ failure as blood flow is compromised. IAH with new signs of organ dysfunction is considered ACS.

Measurement of IAP

The measurement of IAP can be accomplished in several ways, including directly accessing the abdominal cavity with a catheter. It is a very accurate method. Indirect estimates of IAP include:

1. Intravesical-standard technique that is effective, minimally invasive, simple and low cost
• Instillation volume of 25 mL
• Cannot be used with traumatic bladder injury or surgery
2. Intragastric
3. Intrauterine
4. Rectal

The measurements should be taken when the patient is in a flat position or at various elevations, but these measurements should be consistent. The pressure should be read at end-expiration with the transducer zeroed and leveled to the iliac crest in the midaxillary line. These positioning recommendations are based on evidence conducted by the World Society of Abdominal Compartment Syndrome.

Case Study Continues

Approximately 32 hours after admission, the patient began to have decreasing urine output, and peak inspiratory pressures were rising on the ventilator.

The patient’s abdomen became more tense, and the abdominal compartment pressure at that time was 30 mm Hg. Along with these newly developing symptoms, likely related to the increasing IAP, I knew this patient was experiencing IAH and now ACS. I notified the surgeon, and after being examined, the patient was immediately taken to the operating room for a decompressive laparotomy.

Types of ACS

The potentially fatal syndrome of ACS has three different types:

1. Primary ACS is due to a primary intra-abdominal cause such as a major traumatic injury, especially from a penetrating mechanism, pancreatitis, mesenteric venous obstruction, ascites, hemorrhage or abdominal aortic aneurysm.
2. Secondary ACS develops due to an extra-abdominal (cavity) cause such as massive bowel edema from sepsis, capillary leak or massive fluid resuscitation as needed during a cardiopulmonary arrest or from a severe burn. Patients may present with ACS in a variety of different critical care units. Therefore, information on this topic is valuable for nurses working in many clinical areas.
3. Recurrent ACS develops after the resolution of a primary or secondary type of ACS. These entities, which can result in ACS, are seen in recurrent ACS and can be due to an abdominal closure in patients who are edematous with an open abdomen.

Management of ACS

The management of ACS includes proactive measurement of abdominal compartment pressure and a decompressive laparotomy to release increasing pressure in the intra-abdominal compartment. Patients who are candidates for this management strategy include:

• All patients with ACS (IAP greater than 20 mm Hg) with signs of organ dysfunction
• Those with abdominal distention
• Patients who have cardiac, pulmonary and/or renal dysfunction
• Patients with an acute increase of IAP to greater than 25 mm Hg

If an emergent laparotomy is performed for any reason, there are five indications to leave the abdomen open:

• Severe abdominal infection
• Acute mesenteric ischemia
• Necrotizing infection of the abdominal wall
• Damage control laparotomy for trauma
• IAH

An open abdomen is maintained at operation due to bowel edema and aggressive volume resuscitation, rendering fascial closure impossible, so the fascia is left open. Skin is closed over the viscera if possible. If skin closure is not feasible, a temporary abdominal closure will be required, using a variety of commercially available products such as those using negative pressure wound therapy. This type of closure provides several advantages, such as:

• Removal of infected or toxic fluid from the peritoneal cavity
• Prevention of evisceration/tamponade bleeding
• Prevention of the formation of enteroatmospheric fistulas
• Preserving the fascia and abdominal wall domain
• Facilitating reoperation
• Improving the likelihood of early definitive closure

When negative pressure wound therapy is used, there are some added advantages, such as:

• Stimulating cell reproduction and tissue expansion
• Possibly offering protection against IAH and multiple organ dysfunction syndrome (MODS) due to removal of inflammatory mediators/cytokines
• Applying negative pressure to the sponge that facilitates fluid collection/measurement
• Exerting continuous medial traction on fascial edges of the wound pulling them toward the midline to facilitate closure
• Reducing edema in the wound and accelerating wound healing by increasing granulation

Case Study Continued

After surgery, I knew this patient would require a skilled nursing assessment and numerous interventions, such as the following:

Nursing Assessment and Interventions

There are several important nursing assessments and interventions to perform when patients have an open abdomen with temporary wound coverage, including:

• Monitoring for bleeding due to negative pressure (suction).
• Continuing to monitor IAP routinely after applying negative pressure dressing, because edema or bleeding may cause the dressing to become too occlusive. If this occurs, the dressing will need to be removed.
• Monitoring the amount and characteristics of the drainage.
• Protecting the skin from any drainage.

Refer to your organization’s policies and procedures for all the above.

Outcomes of IAH and Open Abdomen

Outcomes of IAH and an open abdomen range from complete fascial closure, which is best accomplished within the first week of its creation, to fascia that cannot be closed. If the fascia cannot be closed, the wound will heal by secondary intention with granulation tissue covering the defect. If a large defect cannot be closed, a large ventral hernia may be the outcome and will require coverage with mesh and a possible skin graft. There is a risk of enteroatmospheric fistula due to the potential for an intestinal wall breakdown from exposure of the tissue to the atmosphere and to leakage of intestinal contents. This complex and challenging complication can result in significant fluid, electrolyte and protein losses from exposed viscera, impaired wound healing and infection. Treating a patient with ongoing intestinal drainage from an open fistula requires complex wound management with the involvement of wound care nurses and other specialists to contain the drainage, protect the skin and optimize nutrition. Surgical interventions to close a fistula are often delayed for months in an effort to decrease the inflammatory response and optimize nutrition.

Patients experiencing ACS who require an open abdomen will need intensive nursing assessments and interventions. Other essential components in the care of patients with ACS and an open abdomen include the provision of early, aggressive, goal-directed nutritional support to decrease the extreme morbidity and mortality associated with these conditions. These patients are critically ill, and anxiety often accompanies the physiologic compromise they experience. The emotional support that critical care nurses provide in these situations is also of the utmost importance.

Case Study Continued

This patient's hospital stay was complicated by other organ dysfunction. However, after a long ICU stay, subsequently being transferred to intermediate care and then to a rehabilitation facility, ultimately the patient made it home.

Was there a time you cared for a patient with ACS?