Chapter 86: Peritoneum and Retroperitoneum Flashcards
What is the Cullens sign?
A characteristic ring of SQ haemorrhage around the umbilicus often seen with haemoperitoneum or peritonitis bu direct extension from the abdominal cavity to the SQ
What lines the pelvic and peritoneal cavities?
Transverse fascia and mesothelial cells (peritoneum)
What are omental milky spots?
A source of neutrophils, macrophages and lymphocytes, an important part of the peritoneal defense mechanism
How would you classify peritoneal fluid as normal, transudate, modified transudate and exudate based on cell count and protein concentration?
Transudate < 1500 cells/uL and <2.5 g/dL
Modified 1500-7k and 2.5-5 g/dL
Exudate >5k and >3 g/dL
What is the predominant cell type in normal peritoneal fluid?
Macrophage
What rate of fluid absorption is the peritoneal cavity capable of?
3-8% of bodyweight per hour
What is normal intraabdominal pressure in dogs?
2 - 7.5 cmH2O
What is required for adhesion formation?
Fibrinous exudate (from surgical manipulation or many diseases)
and vascular damage/ischemia
In the absence of ischemia, fibrin undergoes fibrinolysis. When accompanied by vascular damage, fibrin is infiltrated by fibroblasts which produce collagen and form firm adhesions
In addition to ischemia, what else (4) increases the likelihood of adhesion formation?
- Endotoxemia
- Intestinal manipulation
- Bowel distention
- Dessication of the serosal surfaces
What are (6) ways to reduce the likelihood of adhesion formation?
- Prevention of desiccation (moisten tissues regularly)
- Gentle tissue handling
- Meticulous hemostasis
- Precise suture placement
- Complete removal of blood clots and foreign debris
- Thorough lavage
What are the (5) methods the peritoneum uses for defense?
- Release of complement (C3a, C5a) which stimulates neutrophil chemotaxis and degranulation of basophils and mast cells
- Diaphragmatic lymphatics
- Resident leukocytes and macrophages
- Abscess formation
- Resident natural killer cells
What is the major proinflammatory mediator produced by mesothelial cells?
What stimulates its production?
IL-8
- Stimulated by TNFa and IL-1B from macrophages
What is the main anti-inflammatory mediator in septic peritionitis?
IL-10 - protects against lethal shock
SIRS is proportional to the degree of elevation of what proinflammatory cytokines?
IL-1B
TNFa
IL-6
What (5) substances are known adjuvants in septic peritonitis?
(Intraperitoneal substances which enhance bacterial growth)
- Gastric mucin polysaccharide
- Bile salts
- Haemoglobin
- Barium
- Peritoneal fluid volume
What are some broad functions of the omentum?
- Isolate and seal
- Absorbs bacteria and other particulate matter
- Rich blood supply
- Pronounced angiogenic activity
What is the cause of ileus secondary to septic peritonitis?
- Sympathoadrenergic reflex inhibition which completely blocks myenteric cholinergic neurons
What are the broad classifications of peritonitis?
- Primary or secondary
- Acute or chronic
- Localised or generalised
- Septic or aseptic
List some (6) causes of septic secondary peritonitis?
- GI leakage is most common (50%)
- Genitourinary tract
- hepatobiliary
- surgical (postop) peritonitis MOST LETHAL 85% mortality
- Penetrating wounds
- Complication of peritoneal dialysis (klebsiella)
List some (5) causes of aseptic secondary peritonitis?
- mechanical (irritation/gossipyboma)
- starch granulomatous (surgical glove powder)
- chemical (bile, pancreatic enzymes, urine, barium)
- Sclerosing encapsulating
- Parasitic
What is sclerosing encapsulating peritonitis?
What is the recommended treatment?
A chronic form of peritonitis in which abdominal organs become encased in thick cocoon-like layers of collagenous connective tissue
Surgical exploration and biopsy and corticosteroids
List risk factors for post-op dehiscence and septic peritonitis:
- Pre-op septic peritonitis
- Hypoalbuminaemia
- Hypoproteinaemia
- Intraoperative hypotension
What is highly correlated with nonsurvival in bile peritonitis?
Presence of bacteria.
What is early and late mortality in septic peritonitis most associated with?
Early mortality: Gram negative aerobic organisms associated with high circulating concentrations of endotoxin, particularly E.Coli
Late mortality: Presence of anaerobic organisms
What are the two most common bacteria isolated with bowel perforation? What’s scary about them?
E. Coli
Bacteroides fragilis
They have a bacterial synergism that increases their lethality
What volume of intraperitoneal fluid can be detected by ballottement?
10ml/kg
The inflammatory response in peritonitis is associated with a n influx of protein-rich fluid and what two cell types?
Macrophages and neutrophils
What are two examples of primary peritonitis?
FIP in cats
Bacterial peritonitis of unknown cause / translocation without perf
What is the most common type of peritonitis in dogs?
Secondary peritonitis
What allows E. coli to adapt to the peritoneal environment?
Alpha-Hemolysin exotoxin - allows for invasion and destruction
How do you define SIRS in dogs?
Rectal temp <100.6 or >102.6
HR >120 BPM
Resp >20 / min
WBC >18k or <5k
In cats values slightly different also Bands > 5%
Describe the process of acute abdominal compartment syndrome:
Marked increase in abdominal pressure (>20-25 cmH2O) -> MODS
Pulmonary failure
decreased venous return to the heart
intestinal ischemia and translocation
renal failure / oliguria
hepatic ischemia
POOR prognosis
What is normal peritoneal fluid composed of?
Protein < 3g/dL
No fibrinogen / no clotting
<300 cells with macrophages dominant
How can you quickly stop bleeding in the liver?
place a finger in the epiploic foramen and curl it ventrally to occlude the hepatic artery and portal vein
What percentage of the area of the skin is represented by the peritoneal linings?
150%
Parietal (somatic) and visceral (splanchnic) mesoderm combine to make the peritoneal cavity. What forms from each?
Somatic: Body wall
Splanchnic: Viscera/organs
What are the four natural openings (one is paired) of the peritoneal cavity?
Esophageal hiatus (esophagus, vagus)
Caval hiatus (caudal vena cava)
Aortic hiatus (aorta, azygous, hemi-azygous, thoracic duct)
Inguinal canals (femoral a., femoral v. saphenous n., lymphatics)
