Incidence and Prevalence of Abdominal Compartment Syndrome
Abdominal compartment syndrome occurs with an incidence of approximately 2% and prevalence ranging from 0% to 36.4% depending on the patient population studied 1.
Population-Specific Incidence
The frequency of ACS varies substantially based on the underlying clinical condition and patient population:
- Severe acute pancreatitis: Approximately 15% of patients with severe AP develop intra-abdominal hypertension or ACS 2
- General critically ill populations: The wide prevalence range (0-36.4%) reflects significant variation across different ICU settings and patient risk profiles 1
Mortality Considerations
The mortality associated with ACS is catastrophic, ranging from 50% to nearly 100% depending on the urgency and success of rescue interventions 3, 2. This extraordinarily high mortality rate underscores why recognition and prevention are critical:
- Severe acute pancreatitis with ACS: Mortality rate approximately 50% 2
- Untreated ACS: Universally lethal if not decompressed 4
- Treated ACS: High morbidity and mortality persist even with surgical decompression, with case series showing mortality rates of 29% (2 of 7 patients) despite intervention 4
Risk Factor Prevalence
Understanding which patients are at highest risk helps contextualize when to expect ACS 3:
- Diminished abdominal wall compliance: Major trauma, major burns, abdominal surgery, prone positioning 3
- Increased intra-abdominal contents: Acute pancreatitis, hemoperitoneum, intra-abdominal infection/abscess, ascites 3
- Capillary leak/fluid resuscitation: Massive fluid resuscitation, positive fluid balance, polytransfusion, damage control laparotomy 3
- Other high-risk factors: Sepsis, increased APACHE-II or SOFA scores, hypothermia, acidosis 3
Clinical Context
IAH (the precursor to ACS) is described as a "ubiquitous feature of critical illness/injury" that should be equated with visceral ischemia 3. This suggests that while frank ACS with the 2% incidence is relatively uncommon, the underlying pathophysiology of elevated intra-abdominal pressure is far more prevalent in critically ill patients.
The progression from IAH (IAP ≥12 mmHg) to ACS (IAP ≥20 mmHg with organ dysfunction) represents a continuum, with the World Society of the Abdominal Compartment Syndrome establishing graded severity levels to capture this spectrum 3, 5.
Measurement and Detection Implications
Because clinical examination is inaccurate for detecting raised IAP, the true incidence may be underestimated in settings without protocolized IAP monitoring 3. The WSACS recommends measuring IAP when any known risk factor for IAH/ACS is present in critically ill or injured patients 3, suggesting that systematic surveillance would likely identify more cases than currently reported incidence figures suggest.