Surg - Abdominal Compartment Syndrome Flashcards
Normal IAP
5-7 mmHg
Define Abdominal Perfusion Pressure
APP = MAP - IAP
Define Intra-abdominal hypertension
IAH - sustained or repeated pathologival elevation in IAP above 12 mmHg
Define Abdo compartment syndrome
Sustaned IAP >20mmHg with or without APP<60mmHg associated with NEW organ dysfunction
Grading of ACS
1 - 12-15mmHg
2 - 16-20mmHg
3 - 21-25 mmHg
4 > 26mmHg
How to classify ACS
Primary:Due to pathology of abdomen
Secondary:Extra-abdominal process
Catergorise the risk factors for ACS:
Diminished wall compliance –> surgery, tight closure, trauma, burns, proned
Increased abdominal contents –> Intra-luminal –> ileus, gastroparesis extraluminal –> ascites, haemoperitoneum/pneumo
Capillary leak –> sepsis, trauma, burns, pancreatisis hypothermia, acidosis massive transfusion, positive fluid balance
Other: mechanical vent, PEEP>10, increased head angle, hypotension
Measure IAP
Direct or indirect
Direct - Needle into abdomen - trochar at laparoscopy
Indirect - Intra-vesicle pressure - urinary bladder catheter25mls into catheter, attach drainage bag, cross clamp16g needle to a transducer is attached to culture port site
Resp issues with IAH
Basal atelectasis, collapse, diaphragm splints
Reduced chest wall compliance
V/Q mismatch, hypoxeamia, hypercapnoea
PEEP - worsens venout return and CO
CVS effects of IAH
Raised IAP transmits to vasculature
Reduced CO –> reduced venous return
Leads to reduced APP
Neuro effects of IAH
Raised ICP as cerebral venous return impeded due to raised thoracic pressure
Hypoxaemia causes cerebral vasodilation and worsens ICP
Renal effects
Direct compression of renal vessels, reduces RBF
Pressure on tubules, reduces filtration gradient
Compensatory activates RAAS - worsening insultin
GI/hepatic IAH
Hypoperfusion and venous hypertension - bowel oedema
Ischaemia and translocation
Reduced hep art. flow
Bilary stasis
Principles of management
ABCDE approach treating specific abnromalities as found:
Principles:
Serial monitoring
Medical: Improve wall compliance, sedate, paralyse, analgesia, positioning Fluid - avoid excess resus, consider RRT
Evacuate intra-lumen - gastric decompression, laxatives, pro-kinetics Evacutae extra lumen - collections drained, paracentesis
Organ support - APP>60 with vasopressors
Surgical - laparotostomy negative pressure wound dressing
Complications of IAH
Untreated, 100% mortality
Multi organ failure
