Abdominal Compartment Syndrome

Educational Objectives

The goal of this program is to improve management of abdominal compartment syndrome. After hearing and assimilating this program, the clinician will be better able to:

1. Measure intra-abdominal pressures.

Summary

Definitions: intra-abdominal hypertension (IAH) — sustained pathologic elevation in intra-abdominal pressure (IAP) >12 mmHg in adults and >10 mmHg in children; abdominal compartment syndrome (ACS) — IAH causes organ dysfunction; occurs with IAP >20 mmHg; respiratory dysfunction occurs when elevation of the diaphragm increases peak airway pressures and hinders oxygenation and ventilation; renal dysfunction occurs with compression of the renal vasculature, hindering renal blood flow and decreasing glomerular filtration rate; hemodynamic instability occurs when the inferior vena cava is compressed, increasing central venous pressure and decreasing cardiac output; increased intrathoracic pressure decreases venous drainage from the head and leads to intracranial hypertension; compression of bowel vasculature causes hypoperfusion, compromises the mucosal barrier, and leads to translocation of intestinal bacteria and toxins

Types of ACS: primary ACS — cause is intra-abdominal (eg, trauma, pancreatitis, mesenteric venous obstruction, ascites, small-bowel obstruction, retroperitoneal hemorrhage); secondary ACS — edema occurs due to an extra-abdominal process (eg, sepsis, capillary leak, massive fluid resuscitation [FR], burns); recurrent ACS — ACS recurs following medical or surgical treatment

Grading of IAH: ranked from grades I to IV; grade I IAH occurs in ≈30% of critically ill patients; occurrence decreases and mortality increases with increasing grade severity; normal IAP is 0 mmHg; IAP is 5 mmHg to 7 mmHg in patients with critical illness; IAP between 10 mmHg and 15 mmHg is associated with decreased organ perfusion; IAP >20 mmHg is associated with organ dysfunction and ACS

Measurement of IAP: insertion of a peritoneal dialysis or pigtail catheter into the peritoneal cavity is preferable, though invasive; pressure from intra-abdominal organs can be measured with a nasogastric (NG) or rectal tube or Foley catheter (FC)

Bladder pressure (BP) measurement: the gold standard, as FCs are widely available, low cost, simple to use, and minimally invasive; cannot be performed with bladder trauma, neurogenic bladder, benign prostatic hyperplasia, or pelvic hematoma; contracted abdominal muscles or states of chronically elevated IAP (eg, obesity, pregnancy, radiation cystitis, peritoneal dialysis) create measurement inaccuracy; ensure correct setup of the transducer, as leaks can cause falsely low readings; measure BP every 4 hr to 6 hr; procedure — the FC is initially flushed to remove air bubbles and obstructions with ≤25 cc saline (assumes the bladder is empty); BP is measured at the end of expiration in the supine position, with the transducer zeroed at the level of the iliac crest and midaxillary line; wait 30 sec to 60 sec after saline flush to record the IAP

Suggestions for treatment: the goal is to prevent progression of IAH to ACS; decrease muscle contraction, increase sedation, or induce paralysis to increase abdominal wall compliance; use NG and rectal tubes to evacuate luminal intestinal contents; drain abdominal fluid collections; use diuresis or dialysis to correct a positive fluid balance and maintain net even fluid balance; use of abdominal perfusion pressure ([mean arterial pressure - IAP]; 50-60 mmHg is optimal) to measure FR is controversial; perform early decompressive laparotomy to decrease IAP; this leaves the abdomen open, causes fluid and protein loss, and induces a state of catabolism; prolonged open abdomen causes loss of abdominal wall domain and increases the risk of developing an enteroatmospheric fistula; closure in 4 to 7 days is ideal and can be hastened by restrictive FR and negative-pressure wound therapy; use a bridging mesh if closure is not possible despite clinical improvement

World Society of Abdominal Compartment Syndrome: recommends protocolized BP measurement; treat colonic ileus with NG tube or colonic decompression with promotility agents (eg, neostigmine); has no comment regarding use of diuretics or renal replacement therapy

Readings

Cheatham ML. Abdominal compartment syndrome: pathophysiology and definitions. Scand J Trauma Resusc Emerg Med. 2009;17:10. doi:10.1186/1757-7241-17-10; Kirkpatrick AW, Roberts DJ, De Waele J, et al. Intra-abdominal hypertension and the abdominal compartment syndrome: updated consensus definitions and clinical practice guidelines from the World Society of the Abdominal Compartment Syndrome. Intensive Care Med. 2013;39(7):1190-1206. doi:10.1007/s00134-013-2906-z; Leon M, Chavez L, Surani S. Abdominal compartment syndrome among surgical patients. World J Gastrointest Surg. 2021;13(4):330-339. doi:10.4240/wjgs.v13.i4.330.

Disclosures

For this program, members of the faculty and planning committee reported nothing relevant to disclose.

Acknowledgements

Dr. Lee was recorded at the 27th Annual USC National Trauma, Critical Care and Acute Care Surgery Symposium, held June 17-18, 2021, in Pasadena, CA, and presented by the Keck School of Medicine of the University of Southern California. For information about CME activities from this presenter, please visit www.keck.usc.edu/cme. Audio Digest thanks the speakers and presenters for their cooperation in the production of this program.

ABS Continuous Certification

Successful completion of this CME activity, which includes participation in the evaluation component, enables the learner to earn credit/s toward the CME [and Self-Assessment] requirements of the American Board of Surgery’s Continuous Certification pro

CME/CE INFO

Accreditation:

The Audio- Digest Foundation is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.

The Audio- Digest Foundation designates this enduring material for a maximum of 0.25 AMA PRA Category 1 Credits™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

Audio Digest Foundation is accredited as a provider of continuing nursing education by the American Nurses Credentialing Center's (ANCC's) Commission on Accreditation. Audio Digest Foundation designates this activity for 0.25 CE contact hours.

Lecture ID:

GS692304

Expiration:

This CME course qualifies for AMA PRA Category 1 Credits™ for 3 years from the date of publication.

Instructions:

To earn CME/CE credit for this course, you must complete all the following components in the order recommended: (1) Review introductory course content, including Educational Objectives and Faculty/Planner Disclosures; (2) Listen to the audio program and review accompanying learning materials; (3) Complete posttest (only after completing Step 2) and earn a passing score of at least 80%. Taking the course Pretest and completing the Evaluation Survey are strongly recommended (but not mandatory) components of completing this CME/CE course.

Estimated time to complete this CME/CE course:

Approximately 2x the length of the recorded lecture to account for time spent studying accompanying learning materials and completing tests.