Abdominal Compartment Syndrome

John Hartley

Academic Surgical Unit

The University of Hull

Abdominal Compartment Syndrome (ACS)

Definition

“The adverse physiological consequences of

an acute elevation in intra-abdominal pressure”- Oliguria- Increased airway pressures- Reduced cardiac output

Abdominal Compartment Syndrome

Historical background

The perils of elevated intra-abdominal pressure…• 1890’s elevation of IAP caused death in animal

models• 1911 cardiovascular effects of raised IAP

identified• 1913 effects of raised IAP on renal function• 1980’s abdominal decompression for IAP

Abdominal Compartment Syndrome

Acute elevation IAP >30mmHgPost-op

Acute elevation IAP >30mmHgPost-op

Oliguria in 11 ptsOliguria in 11 pts

7 ptsRe-exploration Decompression

7 ptsRe-exploration Decompression

4 pts Not re-explored

4 pts Not re-explored

Immediate diuresisImmediate diuresisRenal failure

and diedRenal failure

and died

Kron Il, Harman PK, Nolan SP. Ann Surg 1984:199:28-30

Abdominal Compartment Syndrome

abdominal pressure abdominal pressure

Compression of kidneysCompression of kidneys Venous return Venous return Intrathoracic pressures Intrathoracic pressures

Renal blood flow Urine output

Renal blood flow Urine output

CO VEDV SV SVR

Oxygen delivery

CO VEDV SV SVR

Oxygen delivery

Hypoxaemia Airway pressures

Compliance PA pressures CVP readings

Hypoxaemia Airway pressures

Compliance PA pressures CVP readings

ICP

Pathophysiology

Abdominal Compartment SyndromeCauses of raised intra-abdominal pressure (IAP)

Retroperitoneal Intraperitoneal

Oedema in necrotising pancreatitis Haemorrhage

Pelvic haematoma Visceral oedema

Retroperitoneal haematoma Abdominal packing

Bleeding after aortic surgery Bowel dilatation

Oedema related to resuscitation Mesenteric venous obstruction

Pneumoperitoneum

Acute ascites

Abdominal Compartment Syndrome

At risk patients

• Major trauma

• Damage control surgery

• Laparotomy for bleeding, ischaemia etc

• Re-laparotomy for postoperative complications

• Massive volume resuscitation

Abdominal Compartment Syndrome

Clinical features• Abdominal distension• ELEVATED IAP• Consequent organ dysfunction

Importance• Decompression can reverse abnormal physiology• Probable fatal progression if left untreated

Abdominal Compartment Syndrome

Measurement of IAP

• Indirect assessment of IAP by bladder pressure

• 50-100ml saline into bladder

• Manometer readings from symphysis pubis

Abdominal Compartment Syndrome

Problems• What value of IAP should cause concern?• Level beyond which ACS is irreversible?• ABSOLUTE IAP UNHELPFUL

– >20mmHg significant in all pts– >15mmHg significant in many– >12mmHg significant in some

Malbrain ML. Intensive Care Med 1999;25:1453-58

Abdominal Compartment Syndrome

Survey of British practice• 137 of 207 hospitals (66.2% response)• 1.5% (n=2) no knowledge of ACS• Some measurement IAP 76% (n=104)• Upon suspicion of ACS 93% (n=97)• No consensus on frequency of measurement or indication

for decompression

Ravishankar N, Hunter J.Br J Anaesth 2005;94:763-6

Abdominal Compartment Syndrome

Incidence• Prospective measurement of IAP in 9 months

admissions to trauma ICU• 15 of 706 pts IAH (2%)• 6 of 15 pts with IAH developed ACS (1%)• 50% mortality in ACS and 2 of 9 with IAH

Hong JJ, Cohn SM, Perez JM et al Br J Surg2002;89:591-6

Abdominal Compartment Syndrome

Abdominal decompression• Reversal of abnormal parameters in approx 80%• Mean survival approx. 50%• Intervention too late?• Inevitable SIRS and MOF?• PREVENTION BETTER THAN CURE

Sugrue MD’Amour S. J Trauma 2001;51:419

Abdominal Compartment Syndrome

Grade IAP

(mmHg) (cmH2O)

Signs Treatment

I 10-15 13-20 No signs ACS Maintain normovolaemia

II 16-25 21-34 PAWP + oliguria ? Volume resuscitation

III 26-35 35-48 Anuria, CO PAWP Consider decompression

IV >35 >48 Anuria, CO PAWP Mandatory decompression

Proposed grading for ACS based on IAP

Burch JM, Moore EE, Moore FA et al. Surg Clin North Am 1996;76:833-842

Abdominal Compartment Syndrome

Abdominal Compartment Syndrome

Conclusions

• Concept of ACS important

• True incidence and significance unclear

• Increasing awareness and measurement of IAP may lead to:

- Better understanding of pathophysiology

- Evidence based management

Abdominal Compartment Syndrome

• World Society on Abdominal

Compartment Syndrome

• www.wsacs.org

• Antwerp 24th-27th March 2007

Abdominal Compartment Syndrome

Renal effects• IAP 15-20mmHg RBF and GFR with anuria when

>30mmHg• No effect of stenting• Parenchymal compression and renal vascular resistance• Reversible by decompression

Harman PK, Kron IL, McLachlan HD et al Ann Surg1982;196:594-7

Abdominal Compartment Syndrome

Gut and hepatic effects splanchnic and hepatic blood flow flow in animal models with IAP>10mmHg• Ischaemia at >40mmHg• Gastric mucosal acidosis with IAP improves

with decompressionIvatury RR, Porter JM, Simon RJ et al J Trauma1998,44:1016-21

Abdominal Compartment Syndrome

Other means of detection• CT changes

- Narrowing of IVC- Direct renal compression- Bowel wall thickening- “Rounded abdomen”

• Splanchnic hypoperfusion and acidosis• Abdominal perfusion pressure

Abdominal Compartment Syndrome

Management of ACS – the issues

• Indication for decompression

• Timing of decompression

• “point of no return”

• Subsequent laparostomy management

Abdominal compartment syndrome

• Definition

• The adverse physiological consequences that occur as a result of an acute increase in IAP

Abdominal compartment syndrome

• Management of ACS

• Indication for decompression

• Timing of decompression

• “point of no return”

• Subsequent laparostomy management

Abdominal Compartment Syndrome

Effects of intra-abdominal hypertension (IAH)

• Gut and hepatic effects

• Renal effects

• Cardiovascular effects

• Respiratory effects

• CNS

• Abdo wall

Abdominal Compartment Syndrome

Cardiovascular effects venous return by compression of IVC and

portal vein intra-thoracic pressure, LV compliance,

cardiac contractility and CO peripheral oxygen delivery

Abdominal Compartment Syndrome

Respiratory effects

• Elevation of diaphragm, thoracic volume and compliance, intra-pleural pressure

airway pressures to maintain ventilation

• Compressive atelectasis and V/Q mismatch, hypoxia, hypercarbia, acidosis

Abdominal Compartment Syndrome

• Acute elevation of IAP above 30mmHg caused oliguria in 11 postoperative pts

• Re-exploration and decompression in 7 pts resulted in immediate diuresis.

• 4 pts not re-explored developed renal failure and died.• If IAP > 25mmHg in the early post period is assoc. with

oliguria and normal blood pressure and cardiac index, the patient should undergo re-exploration and decompression of the abdomenKron Il, Harman PK, Nolan SP. Ann Surg 1984:199:28-30

Abdominal Compartment Syndrome

CNS effects• Impaired venous return and cerebral pooling intra-cranial pressure

Ertel W, Oberholzer A, Platz A et al Crit CareMed 2000; 28:1747-53

Abdominal Compartment Syndrome

Early detection

• Survey trauma surgeons USA

• 6% measured IAP routinely

• 59% selectively

Mayberry JC, Goldman RK, Mullins RJ.

J Trauma 1999;47:509-513