ABDOMINAL COMPARTMENT SYNDROME (ACS)Leor Arbel, MS-3

Source: DeCou, JM et al. Abdominal compartment syndrome in children: Experience with three cases. Journal of Pediatric Surgery, Volume 35, Issue 6, 840-842.

What is Abdominal Compartment Syndrome (ACS)?

Refers to organ dysfunction caused by intraabdominal hypertension Tx can improve organ dysfunction, so it’s important to consider this diagnosis Primarily affects pts who are already very ill – thus, S/Sx of ACS can be mistakenly

attributed to progression of the primary illness → heightened awareness of ACS is needed!

Intra-Abdominal Hypertension (IAH) is not the same thing as ACS; IAH = sustained Intra-abdominal Pressure (IAP) ≥ 12 mmHg

Note: IAP in critically ill pts between 5 – 7 mmHg is considered normal

For research purposes, ACS = sustained IAP > 20 mmHg Clinically, however, there is no IAP value that reliably diagnoses ACS in all

pts. Therefore, it is more helpful to think of ACS as IAH-induced new organ dysfunction

That said, pts w/IAP < 10 mmHg generally do not have ACS and pts w/IAP > 25 mmHg usu do have ACS

Primary vs Secondary ACS

Primary ACS Secondary ACS

▪ Due to abdominopelvic injury or disease ▪ Examples: Trauma, Hemoperitoneum, Pancreatitis

▪ Due to conditions that do NOT originate in abdominopelvic region but which require extensive fluid resuscitation (→ splanchnic reperfusion)▪ Examples: Fluid resuscitation, Burns, Sepsis

Who gets ACS?

ACS is MC seen in pts who are critically ill, but there is a wide variety in their underlying medical/surgical conditions. Examples include:

TRAUMA – Injured pts in shock who need aggressive fluid resuscitation BURNS – Pts with burns involving >30% of body surface area

ACS vs NEC vs Ischemic bowel SEPSIS – Along with other medical conditions that require extensive fluid

resuscitation and are a/w 3rd spacing of fluids & tissue edema LIVER TRANSPLANTATION RETROPERITONEAL PATHOLOGIES – Eg ruptured AAA (8% of these pts develop

ACS), pelvic fractures, pancreatitis POST-SURGICAL – Pts undergoing operations in which they are given large volume

resuscitation, esp with crystalloid in the face of hemorrhagic or septic shock

Physiologic Manifestations of ACS

Intra-abdominal Hypertension (IAH) can cause dysfunction in nearly every organ system, thereby causing ACS

Table shows a summary of the key physiologic effects a/w elevated intra-abdominal pressure

Physiologic deterioration frequently manifests as end-organ sequelae eg:

↓ urine output ↑ pulmonary inspiratory pressure ↓ cardiac preload ↑ cardiac afterload

Source: UpToDate

Physiologic Manifestations of ACS (cont’d)

This is a better visual representation of the effects discussed on the previous slide

Source: Brunicardi FC, Andersen DK, Billiar TR, Dunn DL, Hunter JG, Matthews JB, Pollock RE. Trauma. Schwartz's Principles of Surgery, 10e (2014)

Signs & Symptoms

Pt is usually critically ill, unable to communicate. Rarely, the pt is verbal & conveys symptoms of malaise, weakness, abdominal pain and

bloating.

Tensely distended abdomen Progressive oliguria Increased ventilatory requirements, acute pulmonary decompensation Hypotension Tachycardia Elevated JVP, JVD Hypoperfusion → cool skin, obtundation, lactic acidosis

Diagnosis

Dx requires that IAP be measured. IAP cannot be reliably determined via physical exam, and S/Sx and imaging findings are also insufficient for Dx.

IAP can be approximated by measuring the patient’s bladder pressure

50 mL saline instilled into bladder via aspiration port of Foley catheter with the drainage tube clamped

3-way stopcock and water manometer are placed at level of pubic symphysis Bladder pressure can then be viewed (in cm of water) on the manometer

Management

No specific bladder pressure prompts therapeutic intervention (unless the pressure is > 35 mmHg)

Emergent decompression is warranted when IAH reaches a level at which end-organ dysfunction is observed

Decompression is usu performed operatively (decompressive laparotomy) In operative decompression with egress of the abdominal contents → temporary

coverage using a subfascial sterile drape and Ioban application is placed over the abdominal viscera

If significant intra-abdominal fluid is a primary component of the pt’s ACS (as opposed to bowel or retroperitoneal edema), decompression can be achieved non-operatively via Percutaneous Drain

Most applicable to pts with major liver injuries

Mortality is directly affected by the timing of decompression: 60% mortality if presumptive decompression 70% mortality if delayed decompression Nearly 100% mortality if no decompression

Operative Decompression

Images from: Smith WR, Stahel P. Management of Musculoskeletal Injuries in the Trauma Patient.

Complications & Other Surgical Considerations

Recognition of ACS and performance of damage control surgery have ↑ pt survival, but at the cost of an open abdomen

Pts with an open abdomen lose btwn 500-2500 mL per day of abdominal effluent (albumin rich fluid). Appropriate volume compensation for this loss remains controversial, both wrt amount and type of replacement (crystalloid vs colloid).

Interestingly, despite having a widely open abdomen, pts can develop recurrent ACS (this ↑ morbidity & mortality)

Therefore, recommended to monitor bladder pressure q4hr. Significant increases in pressure may warrant repeat operative decompression

Following resuscitation & management of specific injuries where applicable, goal of operative team is to close the abdomen as quickly as possible! Doing so promotes fascial closure and minimizes morbidity as well as cost of care.

Delayed abdominal wall reconstruction = greater pt morbidity & resource invasive

Advent of wound VAC technology has revolutionized fascial closure Authors used a sequential closure technique with the wound VAC device on constant fascial

tension with return to the OR every 48 hrs until closure is complete with a success rate of 95%

Mgmt requires frequent operative/percutaneous drainage of abscesses, fistula control and prolonged TPN

Sequential Closure Technique for Open Abdomen with Wound VAC

Source: Brunicardi FC, Andersen DK, Billiar TR, Dunn DL, Hunter JG, Matthews JB, Pollock RE. Trauma. Schwartz's Principles of Surgery, 10e (2014)

Authors’ sequential closure technique for the open abdomen

References DeCou, JM et al. Abdominal compartment syndrome in children: Experience with three cases. Journal of

Pediatric Surgery, Volume 35, Issue 6, 840-842.

Burlew Cn, Moore EE. Trauma. In: Brunicardi F, Andersen DK, Billiar TR, Dunn DL, Hunter JG, Matthews JB, Pollock RE. eds. Schwartz's Principles of Surgery, 10e New York, NY: McGraw-Hill; 2015. http://accessmedicine.mhmedical.com/content.aspx?bookid=980&sectionid=59610848. Accessed March 04, 2017.

Gestring, M. Abdominal Compartment Syndrome in Adults. In: UpToDate, Post TW (Ed), UpToDate, Waltham, MA. (Accessed on March 4, 2017).