Ch 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 by direct extension from the abdominal cavity to the SQ
What lines the pelvic and peritoneal cavities?
Transversalis 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?
What is the predominant cell type in normal peritoneal fluid?
Macrophage
What rate of fluid absorption is the peritoneal cavity capable of?
3-8% BW 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/ischaemia
In the absense of ischaemia, fibrin undergoes fibrinolysis. When accompanied by vascular damage, fibrin is infiltrated by fibroblasts while produce collagen and form firm adhesions
In addition to ischaemia, what else increases the liklihood of adhesion formation?
- Endotoxaemia
- Intestinal manipulation
- Bowel distention
- Dessication of serosal surfaces
List some methods of reducing the liklihood of adhesion formation
- Prevention of dessication
- Gentle tissue handling
- Meticulous haemostasis
- Precise suture placement
- Complete removal of blood clots anf foreign debris
- Thorough lavage
List some methods of peritoneal defense
- Release of complement (C3a, C5a) which stimulates neutrophil chemotaxis and degranulation of basophils and mast cells
- Diaphragmatic lymphatics
- Resident leucocytes 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
SIRS is proportional to the degree of elevation of what proinflammatory cytokines?
- IL-1B
- TNFa
- IL-6
What substances are know 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 causes of aseptic and septic secondary peritonitis
What is sclerosing encapsulating peritonitis?
What is the recommened 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 dehiscense and septic peritonitis
- Pre-op septic peritonitis
- Hypoalbuminaemia
- Hypoproteinaemia
- Intraop hypotension
What is highly correlated with survival in bile periotonitis
Presense 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: Presense of anaerobic organisms
What are the two most common bacteria isolated with bowel perforation?
- E.Coli
- Bacteroides fragilis
What volume of intraperitoneal fluid can be detected by ballottement?
10ml/kg
How much fluid is instilled for diagnostic peritoneal lavage?
20-22ml/kg warmed sterile isotonic saline
What are some reasonable empirical ABx options?
Bactericidal drugs effective against gram positive and gram negative aerobes and anaerobes
What is the minimal amount of lavage fluid recommended?
200-300ml/kg or until the fluid is returning clear
What is the reasoning behind serosal patching in septic peritonitis?
Strong proteolytic activity in peritonitis degrades collagen and extracellular matrix which may predispose to dehiscense
List broad options of coeliotomy closure after treatment of septic peritonitis?
- Primary closure
- Open peritoneal drainage
- Closed peritoneal drainage
What is considered a conditionally essential amino acid during catabolic illness?
Glutamine
What intraop drug has been significantly associated with a greater short term survival?
Lidocaine
List some negative prognostic indicators of septic peritonitis
- Refractory hypotension
- Elevated ALT, GGT
- Plasma lactate over 2.5mmol/L or inability to normalise
- Ionised hypocalcaemia
- Multiorgan dysfunction
What is the most common bacteris isolated from dog and cate bite wounds?
Pasteurella multocida
What are the most common bacteria isolated from gun shot wounds?
- Staphylococcus spp
- Clostridium spp
What is the most common organism isolated from intraabdominal abscesses?
Bacteroides fragilis
What was the mortality rate of traumatic haemoperitoneum cases which required a blood transfusion?
Mortality 27%
What is the most common primary retroperitoneal tumour?
Lipoma
What are the most common causes of retroperitonitis?
- FB migration
- Ovarian pedicle granuloma
What is a mesothelioma?
To what exposure is it often seen in relation to?
Neoplasms arising from the mesothelial lining of the coeliomic cavities (peritoneal, pleural, pericardial)
- Often seen in relation to asbestos exposure
