Chapter 86: Peritoneum and Retroperitoneum

Question 1

What is the Cullens sign?

Answer 1

A characteristic ring of SQ hemorrhage around the umbilicus often seen with hemoperitoneum or peritonitis by direct extension from the abdominal cavity to the SQ

Question 2

What lines the pelvic and peritoneal cavities?

Answer 2

Transverse fascia and mesothelial cells (peritoneum)

Question 3

What are omental milky spots?

Answer 3

A source of neutrophils, macrophages and lymphocytes, an important part of the peritoneal defense mechanism

Question 4

How would you classify peritoneal fluid as normal, transudate, modified transudate and exudate based on cell count and protein concentration?

Answer 4

Normal < 300 cells/uL and < 3 g/dL
Transudate < 1500 cells/uL and <2.5 g/dL
Modified 1500-7k and 2.5-7.5 g/dL
Exudate >5k and >3 g/dL

Question 5

What is the predominant cell type in normal peritoneal fluid?

Answer 5

Macrophage

Question 6

What rate of fluid absorption is the peritoneal cavity capable of?

Answer 6

3-8% of bodyweight per hour

Question 7

What is normal intraabdominal pressure in dogs?

Answer 7

2 - 7.5 cmH2O

Question 8

What is required for adhesion formation?

Answer 8

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

Question 9

In addition to ischemia, what else (4) increases the likelihood of adhesion formation?

Answer 9

• Endotoxemia
• Intestinal manipulation
• Bowel distention
• Dessication of the serosal surfaces

Question 10

What are (6) ways to reduce the likelihood of adhesion formation?

Answer 10

• Prevention of desiccation (moisten tissues regularly)
• Gentle tissue handling
• Meticulous hemostasis
• Precise suture placement
• Complete removal of blood clots and foreign debris
• Thorough lavage

Question 11

What are the (5) methods the peritoneum uses for defense?

Answer 11

• Release of complement (C3a, C5a) which stimulates neutrophil chemotaxis and degranulation of basophils and mast cells
• Diaphragmatic lymphatics
• Resident macrophages and leukocytes
• Resident natural killer cells
• Abscess formation

Question 12

What is the major proinflammatory mediator produced by mesothelial cells?
What stimulates its production?

Answer 12

IL-8
- Stimulated by TNFa and IL-1B from macrophages

Question 13

What is the main anti-inflammatory mediator in septic peritionitis?

Answer 13

IL-10 - protects against lethal shock

Question 14

SIRS is proportional to the degree of elevation of what proinflammatory cytokines?

Answer 14

IL-1B
TNFa
IL-6

Question 15

What (5) substances are known adjuvants in septic peritonitis?
(Intraperitoneal substances which enhance bacterial growth)

Answer 15

• Gastric mucin polysaccharide
• Bile salts
• Haemoglobin
• Barium
• Peritoneal fluid volume

Question 16

What are some broad functions of the omentum?

Answer 16

• Isolate and seal
• Absorbs bacteria and other particulate matter
• Rich blood supply
• Pronounced angiogenic activity

Question 17

What is the cause of ileus secondary to septic peritonitis?

Answer 17

• Sympathoadrenergic reflex inhibition which completely blocks myenteric cholinergic neurons

Question 18

What are the broad classifications of peritonitis?

Answer 18

• Primary or secondary
• Acute or chronic
• Localised or generalised
• Septic or aseptic

Question 19

List some (6) causes of septic secondary peritonitis?

Which is most common?

Which is most lethal?

Answer 19

1. GI leakage is most common (50%)
2. Genitourinary tract
3. hepatobiliary
4. surgical (postop) peritonitis MOST LETHAL 85% mortality
5. Penetrating wounds
6. Complication of peritoneal dialysis (klebsiella)

Question 20

List some (6) causes of aseptic secondary peritonitis?

Answer 20

1. mechanical (irritation/gossipyboma)
2. starch granulomatous (surgical glove powder)
3. chemical (bile, pancreatic enzymes, urine, barium)
4. Sclerosing encapsulating
5. Parasitic
6. Protozoal

*last two in text, not table

Question 21

What is sclerosing encapsulating peritonitis?
What is the recommended treatment?

Answer 21

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

Question 22

List risk factors for post-op dehiscence and septic peritonitis:

Answer 22

• Pre-op septic peritonitis
• Hypoalbuminaemia
• Hypoproteinaemia
• Intraoperative hypotension

Question 23

What is highly correlated with nonsurvival in bile peritonitis?

Answer 23

Presence of bacteria.

Question 24

What is early and late mortality in septic peritonitis most associated with?

Answer 24

Early mortality: Gram negative aerobic organisms associated with high circulating concentrations of endotoxin, particularly E.Coli

Late mortality: Presence of anaerobic organisms

Question 25

What are the two most common bacteria isolated with bowel perforation? What's scary about them?

Answer 25

E. Coli Bacteroides fragilis They have a bacterial synergism that increases their lethality

Question 26

What volume of intraperitoneal fluid can be detected by ballottement?

Answer 26

10ml/kg

Question 27

The inflammatory response in peritonitis is associated with an influx of protein-rich fluid and what two cell types?

Answer 27

Macrophages and neutrophils

Question 28

What are two examples of primary peritonitis?

Answer 28

FIP in cats Bacterial peritonitis of unknown cause / translocation without perf

Question 29

What is the most common type of peritonitis in dogs?

Answer 29

Secondary peritonitis

Question 30

What allows E. coli to adapt to the peritoneal environment?

Answer 30

Alpha-Hemolysin exotoxin - allows for invasion and destruction

Question 31

How do you define SIRS in dogs? What Temp, HR, Resp, WBC #?

Answer 31

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%

Question 32

Describe the process of acute abdominal compartment syndrome:

Answer 32

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

Question 33

What is normal peritoneal fluid composed of? Primary cell? What's not in it?

Answer 33

<300 cells & protein < 3g/dL Primarily macrophages No fibrinogen / no clotting

Question 34

How can you quickly stop bleeding in the liver? Bonus: how long can you occlude it for?

Answer 34

place a finger in the epiploic foramen and curl it ventrally to occlude the hepatic artery and portal vein 10-15 minutes (CH 18)

Question 35

What percentage of the area of the skin is represented by the peritoneal linings?

Answer 35

150%

Question 36

Parietal (somatic) and visceral (splanchnic) mesoderm combine to make the peritoneal cavity. What forms from each?

Answer 36

Somatic: Body wall Splanchnic: Viscera/organs

Question 37

What are the five natural openings (two are paired) of the peritoneal cavity?

Answer 37

1)Esophageal hiatus (esophagus, vagus) 2)Caval hiatus (caudal vena cava) 3)Aortic hiatus (aorta, azygous, hemi-azygous, thoracic duct) 4)Inguinal canals (spermatic cord, vaginal process, round ligament, external pudendal vessels, genital n.) 5)Right/left vascular lacunae (femoral a., femoral v. saphenous n., lymphatics)