1. Update on Abdominal Compartment Syndrome Joint Hospital Surgical Grand Round Dr. Leung Tak Lun Canice Prince of Wales Hospital

3. Definition Abdominal compartment syndrome (ACS) – adverse physiological consequences that occur as a result of an acute increase in IAP Burch et al. Surg Clin North Am 1996;76:834-422 – increased abdominal pressure with increased airway pressure, hypoxia, and oliguria Ivatury et al. Surg Clin North Am 1997;77:783-99

4. Definition Primary ACS – abdominal injury is present Secondary ACS –In patients with severe shock requiring massive resuscitation –Without abdominal injury

5. Risk Factors Severe penetrating and blunt abdominal trauma Ruptured abdominal aortic aneurysm Retroperitoneal haemorrhage Pneumoperitoneum Neoplasm Pancreatitis Massive ascites Liver transplantation Abdominal wall burn eschar Crit Care 2000, 4:23-29

6. Pathophysiology Pulmonary function –Mechanical –Decreased lung compliance –Increased pulmonary vascular resistance –Manifest as hypoxia, hypercapnia, increasing ventilatory pressure

7. Renal –Reduction in renal plasma flow –Direct pressure effect on the parenchyma –Activation of renin-angiotension system –In a prospective study u/o < 0.5mL/kg/min in 65% patient with IAP between 16-25mmHg Oliguric in 100% of patient with IAP > 35mmHg Meldrum et al Am J Surg 1997:174:667-72

8. Cardiovascular –Reduction in CO Decreased venous return Reduction in end-diastolic volume Splanchnic blood flow decreased –Decreased cardiac output –Abnormal mucosal barrier, bacterial translocation, septic complication

9. CNS dysfunction –Elevation in ICP –Impaired venous outflow

10. Measurement?

11. Techniques Direct –Catheter in the peritoneum Indirect –Bladder –Stomach –Rectal pressure –Uterine pressure –Inferior vena cava pressure

12. Intravesical pressure measurement –First described by Kron in 1984 Foley catheter Instillation of 50ml normal saline Clamped distal to the culture aspiration port A 16G needle inserted into the aspiration port and connected to a 3-way connector or pressure tranducer Pubic symphysis is used as the zero point

13. Management Definitive treatment is decompressive laparotomy

14. Abdominal compartment syndrome grading system Grade Bladder pressure (mmHg)Recommendation I10-15 Maintain normovolaemia II16-25 Hypervolaemic resuscitation III26-35Decompression IV>35 Decompression and re-exploration Meldrum et al. Am J Surg.1997;174:667-672

15. Management Decompress when –IAP persistently > 20mmHg Ivatury et al Sury Clinic North Am 1997;77:783-800 –IAP > 20mmHg with U/O < 0.5ml/kg/min PIP > 45mmHg Oxygen delivery < 600 –IAP > 26mmHg Meldrum et al. Surg Clinic North Am 1997;77/801-11

16. Complications Reperfusion Syndrome –Occurs when IAH is suddenly relieved –Sudden increase in tidal volume, causing respiratory alkalosis –Sudden increase of products of anaerobic metabolism –Arrhythmia and asystole

17. How to management the open abdomen?

18. Towel Clip closure

19. Bogota bag

20. Vacuum-assisted wound closure G.B. Garner et al. Am J Surg 2001;182:630-638

21. After the acute phase…………..

22. Primary closure could be carried out in 50- 60% patient after 7-10days Absorbable mesh and skin graft –Large ventral hernia –Require repair later

23. Bring Home Messages ACS is a life-threatening condition Mortality 10.6 -68% Crit care 2000, 4:23-29 Early recognition and treatment is essential for improving outcome Decompress when IAP > 20mmHg with deranged physiological parameter