Difference between revisions of "Gastric Dilation and Intestinal Obstruction – Rabbit"

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===Introduction: gastric dilation and gut stasis===
 
 
===The difference between gastric dilation and gut stasis===
 
 
Gastric stasis must be differentiated from gastric dilation which is usually associated with intestinal obstruction. Gastric dilation develops rapidly, suddenly and unexpectedly, whereas gut stasis develops slowly and insidiously, usually followed by a painful or stressful episode. Note that a moving foreign body could mimic gut stasis except that the stomach is not impacted (stomach may or may not be impacted).
 
Gastric stasis must be differentiated from gastric dilation which is usually associated with intestinal obstruction. Gastric dilation develops rapidly, suddenly and unexpectedly, whereas gut stasis develops slowly and insidiously, usually followed by a painful or stressful episode. Note that a moving foreign body could mimic gut stasis except that the stomach is not impacted (stomach may or may not be impacted).
 
   
 
   
Line 7: Line 5:
 
*Harcourt Brown F M (2007), Gastric dilation and intestinal obstruction in 76 rabbits. Veterinary Record, 161,  409 – 414, and  
 
*Harcourt Brown F M (2007), Gastric dilation and intestinal obstruction in 76 rabbits. Veterinary Record, 161,  409 – 414, and  
 
*Harcourt Brown T R (2007) Management of Acute Gastric Dilation in Rabbits. Journal of Exotic Pet Medicine, 16, (3) 168 – 174
 
*Harcourt Brown T R (2007) Management of Acute Gastric Dilation in Rabbits. Journal of Exotic Pet Medicine, 16, (3) 168 – 174
 
  
 
===Pathophysiology===
 
===Pathophysiology===
Line 20: Line 17:
 
**note dilation of gut proximal to obstruction
 
**note dilation of gut proximal to obstruction
 
*Non-passage of the blockage leads to devitalisation and necrosis of intestine
 
*Non-passage of the blockage leads to devitalisation and necrosis of intestine
 
  
 
===Clinical Signs of Gastric Dilation===
 
===Clinical Signs of Gastric Dilation===
Line 29: Line 25:
 
*Distended stomach palpable in left epigastric area caudomedial to left last rib and confirmed radiographically
 
*Distended stomach palpable in left epigastric area caudomedial to left last rib and confirmed radiographically
 
*Abdominal pain or flaccidity
 
*Abdominal pain or flaccidity
 
  
 
===Causes of intestinal obstruction===
 
===Causes of intestinal obstruction===
Line 41: Line 36:
 
*Tapeworm cysts
 
*Tapeworm cysts
 
*Diverticulosis
 
*Diverticulosis
 
  
 
===Pellets of compressed hair===
 
===Pellets of compressed hair===
Line 49: Line 43:
 
*Ingestion of hair in caecotrophs                                                               
 
*Ingestion of hair in caecotrophs                                                               
 
*Predisposed by low-fibre diets
 
*Predisposed by low-fibre diets
 
  
 
===Sites and causes of obstruction===
 
===Sites and causes of obstruction===
*Pylorus (Deeb 2000 Jenkins 2003)
+
*Pylorus (Deeb 2000; Jenkins 2003)
 
*Proximal duodenum  
 
*Proximal duodenum  
 
**foreign bodies
 
**foreign bodies
Line 70: Line 63:
  
 
'''NB: Severity of prognosis is directly proportional to closeness of site of obstruction to pylorus.'''
 
'''NB: Severity of prognosis is directly proportional to closeness of site of obstruction to pylorus.'''
 
  
 
===Case assessment===
 
===Case assessment===
Line 82: Line 74:
 
|bgcolor="#FFFFCC"| Unresponsive; collapsed; hypothermic; abdominal pain; +/- gastric dilation
 
|bgcolor="#FFFFCC"| Unresponsive; collapsed; hypothermic; abdominal pain; +/- gastric dilation
 
|bgcolor="#FFFFCC"| Gas in stomach and intestine; free gas in peritoneal cavity
 
|bgcolor="#FFFFCC"| Gas in stomach and intestine; free gas in peritoneal cavity
|bgcolor="#FFFFCC"|
+
|bgcolor="#FFFFCC"| Ruptured gut; explorotomy; euthanasia
 
|-  
 
|-  
|bgcolor="#FFFFCC"|  
+
|bgcolor="#FFFFCC"| Unresponsive; abdominal pain; gastric dilation palpable
|bgcolor="#FFFFCC"|  
+
|bgcolor="#FFFFCC"| Gas/fluid in stomach; minimal gas in intestine
|bgcolor="#FFFFCC"|
+
|bgcolor="#FFFFCC"| Cranial sm int obstruction; gastric decompression and surgery; euthanasia
 
|-
 
|-
|bgcolor="#FFFFCC"|  
+
|bgcolor="#FFFFCC"| Unresponsive; abdominal pain; gastric dilation palpable
|bgcolor="#FFFFCC"|  
+
|bgcolor="#FFFFCC"| Gas/fluid in stomach; much gas in small intestine
|bgcolor="#FFFFCC"|  
+
|bgcolor="#FFFFCC"| Caudal sm int obstruction; repeat rads (30-60 mins) or perform gastric decompression
 
|-
 
|-
|bgcolor="#FFFFCC"|
+
|bgcolor="#FFFFCC"| Depressed; not collapsed; palpably enlarged stomach
|bgcolor="#FFFFCC"|  
+
|bgcolor="#FFFFCC"| Gas in caecum
|bgcolor="#FFFFCC"|
+
|bgcolor="#FFFFCC"| Foreign body has passed through; medical treatment
 
|-
 
|-
 
|}
 
|}
 
 
 +
 +
''Performing surgery only to find that the obstruction has moved is preferable to performing a post-mortem examination on a rabbit that required surgical intervention.'' (Harcourt Brown T R (2007), Journal of Exotic Pet Medicine. 16, (3) 168-174)
 +
 +
===Procedure with a case of gastric dilation===
 +
 +
Radiograph under opiate analgesia - fentanyl/fluanisone ((Hypnorm; Janssen-Cilag) SC once only or buprenorphine (Vetergesic; Alstoe) plus meloxicam (Metacam; Boehringer Ingelheim) or carprofen (Rimadyl; Pfizer).
 +
Prepare orthogonal radiographs - lateral and dorso-ventral with legs extended or ventro-dorsal views. Observe the dilation of the stomach and the presence and distribution of fluid (liquid and gas) in the gastrointestinal tract to identify location of obstruction. Note the degree of contact of the dilated stomach with the ventral abdominal wall. Assess the amount of gas in the small intestine and look for gas in the large intestine. If no gas in hindgut and stomach severely dilated it may be best to go for euthanasia. Free gas in peritoneum indicates rupture of the gastrointestinal tract and justifies euthanasia. A search for other pathology may indicate other problems like bladder stones, spinal arthritis etc and may also indicate euthanasia.
 +
 +
Pit-falls of radiography: Caecum and large intestine generally do not have large amounts of gas in normal rabbits BUT caecum and large intestine generally do not have no gas in obstructed rabbits Caecum and large intestine with gas and dilated stomach seen in cases carrying a better prognosis.
 +
 +
Search for peritoneal gas in rabbits with severe depression If found, this is an indication of rupture of the intestine and indicates euthanasia. Remember euthanasia always an option
 +
 +
Serial radiographs (every 30 – 90 minutes) looking for gas in hindgut. If gas in hind gut this indicates that the obstruction is moving - administer NSAIDs (carprofen or meloxicam) if not already administered (see above) - followed by prokinetics if still anorectic after 2-3 hours.
 +
 +
Fluid accumulation in stomach leads to deficit in intra- and extra-cellular compartments. Parenteral fluids required. Give Hartmann’s/kg /hr IV.
 +
 +
Exploratory surgery may be attempted. Decision of whether to embark on surgery or conservative treatment depends on the time of presentation and on  financial considerations:
 +
*Day => conservative treatment
 +
*Night => surgery more likely
 +
 +
===Surgical Procedure===
 +
*Insert stomach tube to decompress: if it blocks, remove, flush and replace
 +
**Procedure of gastric decompression
 +
***+/- sedation
 +
***mouth to last rib
 +
***gentle gastric massage
 +
***patience
 +
***minimal suction
 +
***intermittent retropulsion
 +
***if tube is placed inadvertently endotracheally there will be
 +
*a change in breathing pattern
 +
*the presence of breath sounds at the free end of the tube
 +
*intraluminal condensation
 +
*Gastric rupture => euthanasia
 +
*Intestinal rupture => euthanasia
 +
*Intestinal neoplasm => euthanasia
 +
*Intestinal FB milked through ileocaecocolic junction into the hind gut or perform an enterotomy.
 +
*Note small omentum so omentalisation may not be possible
 +
*Postoperatively give antibiotics, prokinetics, food (force fed with Oxbow Critical Care Formula and baby cereal)
 +
 +
===Practical approach to exploratory laparotomy in rabbits with intestinal obstruction===
 +
#Opiate premedication, oxygenation, gastric and tracheal intubation and isoflurane maintenance.
 +
#Incision midline, sternum to umbilicus
 +
#Inspect retroperitoneum for fluid/ingesta
 +
#Palpate stomach and descending duodenum
 +
#Palpate ascending duodenum (under caecum)
 +
#Palpate jejunum cranially and caudally
 +
#Look for flattened intestine caudal to obstruction
 +
#Examine site of obstruction for contributive or subsequent pathology: cytology/biopsy?
 +
#Milk obstruction to hindgut or stomach
 +
#Gastrotomy/enterotomy/ectomy???
 +
#Closure with Vicryl (not catgut)
  
Unresponsive
+
===Complications of rabbit intestinal surgery===
Collapsed
+
*Insufficient omentum for omentalisation
Hypothermic
+
*Intestine small and thin-walled
Abdominal pain
+
*Food cannot be withheld during post-operative period
+/- gastric dilation
+
**danger of hepatic lipidosis
  
Gas in stomach and intestine
+
===Postoperative care===
Free gas in peritoneal cavity
+
*Warmth, quiet
 +
*Fluid therapy
 +
*Analgesia
 +
*Antibiotics
 +
*Prokinetics
 +
*Food (grass, dandelions)
 +
*Gavage with Oxbow CCF and Baby cereal
  
Ruptured gut
+
{{Learning
Explorotomy
+
|Vetstream = [https://staging.vetstream.com/lapis/Content/Freeform/fre00011#section2 Gastric dilation and stasis]
Euthanasia
+
}}
Unresponsive
 
Abdominal pain
 
Gastric dilation palpable Gas/fluid in stomach
 
Minimal gas in intestine Cranial  sm int obstruction
 
Gastric decompression and surgery
 
?Euthanasia
 
Unresponsive
 
Abdominal pain
 
Gastric dilation palpable Gas/fluid in stomach
 
Much gas in small intestine Caudal  sm int obstruction
 
Repeat rads (30-60 mins) or
 
perform gastric decompression
 
Depressed
 
Not collapsed
 
Palpably enlarged stomach Gas in caecum Foreign body has passed through
 
Medical treatment
 
 
“Performing surgery only to find that the obstruction has moved is preferable to performing a post-mortem examination on a rabbit that required surgical intervention”. Harcourt Brown T R (2007) Journal of Exotic Pet Medicine 16 (3) 168-174
 
  
Procedure with a case of gastric dilation
+
==References==
• Radiograph under opiate analgesia - fentanyl/fluanisone ((Hypnorm; Janssen-Cilag) 0.2-0.3ml/kg SC once only or buprenorphine 0.01-0.05mg/kg SC/IM/IV q 6-12hrs (Vetergesic; Alstoe) plus meloxicam (Metacam; Boehringer Ingelheim) 0.1-0.3mg/kg SC/IM q24h or carprofen (Rimadyl; Pfizer) 2-4mg/kg SC/IM q24hr. Prepare orthogonal radiographs - lateral and dorso-ventral with legs extended or ventro-dorsal views. Observe the dilation of the stomach and the presence and distribution of fluid (liquid and gas) in the gastrointestinal tract to identify location of obstruction. Note the degree of contact of the dilated stomach with the ventral abdominal wall. Assess the amount of gas in the small intestine and look for gas in the large intestine. If no gas in hindgut and stomach severely dilated it may be best to go for euthanasia. Free gas in peritoneum indicates rupture of the gastrointestinal tract and justifies euthanasia. A search for other pathology may indicate other problems like bladder stones, spinal arthritis etc and may also indicate euthanasia.
+
*Deeb, B. (2000) Digestive System and Disorders in '''Manual of Rabbit Medicine and Surgery''', ed. Paul Flecknell pub BSAVA  Cheltenham Glos Pages 39 - 46
• Pit-falls of radiography: Caecum and large intestine generally do not have large amounts of gas in normal rabbits BUT caecum and large intestine generally do not have no gas in obstructed rabbits Caecum and large intestine with gas and dilated stomach seen in cases carrying a better prognosis.
+
*Harcourt Brown, F. M. (2007) '''Gastric dilation and intestinal obstruction in 76 rabbits'''. Veterinary Record, 161, 409 – 414
• Search for peritoneal gas in rabbits with severe depression If found, this is an indication of rupture of the intestine and indicates euthanasia. Remember euthanasia always an option
+
*Harcourt Brown, T. R. (2007) '''Management of Acute Gastric Dilation in Rabbits'''. Journal of Exotic Pet Medicine, 16, (3) 168 – 174
• Serial radiographs (every 30 – 90 minutes) looking for gas in hindgut. If gas in hind gut this indicates that the obstruction is moving - administer NSAIDs (carprofen or meloxicam) if not already administered (see above) - followed by prokinetics if still anorectic after 2-3 hours.
 
• Fluid accumulation in stomach leads to deficit in intra- and extra-cellular compartments. Parenteral fluids required. Give 10-20 ml Hartmann’s/kg /hr IV
 
• Exploratory surgery may be attempted. Decision of whether to embark on surgery or conservative treatment depends on
 
o the time of presentation:
 
• Day => conservative treatment
 
• Night=> surgery more likely
 
o and on  financial considerations
 
  
Surgical Procedure
 
• Insert stomach tube to decompress: if it blocks, remove, flush and replace
 
o Procedure of gastric decompression
 
 +/- sedation
 
 mouth to last rib
 
 gentle gastric massage
 
 patience
 
 minimal suction
 
 intermittent retropulsion
 
 if tube is placed inadvertently endotracheally there will be
 
• a change in breathing pattern
 
• the presence of breath sounds at the free end of the tube
 
• intraluminal condensation
 
• Gastric rupture => euthanasia
 
• Intestinal rupture => euthanasia
 
• Intestinal neoplasm => euthanasia
 
• Intestinal FB milked through ileocaecocolic junction into the hind gut or perform an
 
enterotomy.
 
• Note small omentum so omentalisation may not be possible
 
• Postoperatively give antibiotics, prokinetics, food (force fed with Oxbow Critical Care Formula and baby cereal)
 
  
Practical approach to exploratory laparotomy in rabbits with intestinal obstruction
+
[[Category:Rabbit Digestion]]
1. Opiate premedication, oxygenation, gastric and tracheal intubation and isoflurane maintenance.
 
2. Incision midline, sternum to umbilicus
 
3. Inspect retroperitoneum for fluid/ingesta
 
4. Palpate stomach and descending duodenum
 
5. Palpate ascending duodenum (under caecum)
 
6. Palpate jejunum cranially and caudally
 
7. Look for flattened intestine caudal to obstruction
 
8. Examine site of obstruction for contributive or subsequent pathology
 
 Cytology/biopsy?
 
9. Milk obstruction to hindgut or stomach
 
10. Gastrotomy/enterotomy/ectomy???
 
11. Closure with Vicryl (not catgut)
 
Complications of rabbit intestinal surgery
 
• Insufficient omentum for omentalisation
 
• Intestine small and thin-walled
 
• Food cannot be withheld during post-operative period
 
o danger of hepatic lipidosis
 
Postoperative care
 
• Warmth, quiet
 
• Fluid therapy
 
• Analgesia
 
• Antibiotics
 
• Prokinetics
 
• Food (grass, dandelions)
 
• Gavage with Oxbow CCF and Baby cereal
 
[[Category:Digestive_Disorders_-_Rabbit]]
 

Latest revision as of 17:55, 25 August 2015

Introduction: gastric dilation and gut stasis

Gastric stasis must be differentiated from gastric dilation which is usually associated with intestinal obstruction. Gastric dilation develops rapidly, suddenly and unexpectedly, whereas gut stasis develops slowly and insidiously, usually followed by a painful or stressful episode. Note that a moving foreign body could mimic gut stasis except that the stomach is not impacted (stomach may or may not be impacted).

For more information, see:

  • Harcourt Brown F M (2007), Gastric dilation and intestinal obstruction in 76 rabbits. Veterinary Record, 161, 409 – 414, and
  • Harcourt Brown T R (2007) Management of Acute Gastric Dilation in Rabbits. Journal of Exotic Pet Medicine, 16, (3) 168 – 174

Pathophysiology

(Pathological) obstruction of small intestine accompanied by (physiological) continuous production of saliva which leads to:

  • Accumulation of fluid in stomach and small intestine cranial to obstruction
  • Fermentation => gas production
  • Painful gastrointestinal dilation
  • Reduced gut motility
  • Secondary ileus.
  • Sequestration of fluid => electrolyte and acid-base imbalances and hypovolaemia (and the necessity of fluid therapy.
  • Passage of blockage to hind gut
    • note dilation of gut proximal to obstruction
  • Non-passage of the blockage leads to devitalisation and necrosis of intestine

Clinical Signs of Gastric Dilation

  • Anorexia
  • Depression
  • Moribund/unresponsive
  • Death (due to peritonitis or shock)
  • Distended stomach palpable in left epigastric area caudomedial to left last rib and confirmed radiographically
  • Abdominal pain or flaccidity

Causes of intestinal obstruction

  • Compressed hair
  • Intestinal neoplasia
    • Lymphoma
  • Foodstuff
  • Post-spay adhesions
  • Post-castration strangulated hernia
  • Foreign fibre
  • Tapeworm cysts
  • Diverticulosis

Pellets of compressed hair

They are acquired by:

  • grooming/moulting
  • Ingestion of matted hair
  • Ingestion of hair in caecotrophs
  • Predisposed by low-fibre diets

Sites and causes of obstruction

  • Pylorus (Deeb 2000; Jenkins 2003)
  • Proximal duodenum
    • foreign bodies
    • mid-small intestine
    • foreign bodies
    • neoplasia
    • strangulated hernia
    • diverticulosis
  • Ileocaecocolic junction
    • foreign bodies
    • neoplasia
  • Large intestine
    • neoplasia
    • carpet fibre at fusus coli
    • postspay adhesions
    • tapeworm cysts along attachment with small intestine

NB: Severity of prognosis is directly proportional to closeness of site of obstruction to pylorus.

Case assessment

Clinical signs Radiographic signs Conclusion
Unresponsive; collapsed; hypothermic; abdominal pain; +/- gastric dilation Gas in stomach and intestine; free gas in peritoneal cavity Ruptured gut; explorotomy; euthanasia
Unresponsive; abdominal pain; gastric dilation palpable Gas/fluid in stomach; minimal gas in intestine Cranial sm int obstruction; gastric decompression and surgery; euthanasia
Unresponsive; abdominal pain; gastric dilation palpable Gas/fluid in stomach; much gas in small intestine Caudal sm int obstruction; repeat rads (30-60 mins) or perform gastric decompression
Depressed; not collapsed; palpably enlarged stomach Gas in caecum Foreign body has passed through; medical treatment


Performing surgery only to find that the obstruction has moved is preferable to performing a post-mortem examination on a rabbit that required surgical intervention. (Harcourt Brown T R (2007), Journal of Exotic Pet Medicine. 16, (3) 168-174)

Procedure with a case of gastric dilation

Radiograph under opiate analgesia - fentanyl/fluanisone ((Hypnorm; Janssen-Cilag) SC once only or buprenorphine (Vetergesic; Alstoe) plus meloxicam (Metacam; Boehringer Ingelheim) or carprofen (Rimadyl; Pfizer). Prepare orthogonal radiographs - lateral and dorso-ventral with legs extended or ventro-dorsal views. Observe the dilation of the stomach and the presence and distribution of fluid (liquid and gas) in the gastrointestinal tract to identify location of obstruction. Note the degree of contact of the dilated stomach with the ventral abdominal wall. Assess the amount of gas in the small intestine and look for gas in the large intestine. If no gas in hindgut and stomach severely dilated it may be best to go for euthanasia. Free gas in peritoneum indicates rupture of the gastrointestinal tract and justifies euthanasia. A search for other pathology may indicate other problems like bladder stones, spinal arthritis etc and may also indicate euthanasia.

Pit-falls of radiography: Caecum and large intestine generally do not have large amounts of gas in normal rabbits BUT caecum and large intestine generally do not have no gas in obstructed rabbits Caecum and large intestine with gas and dilated stomach seen in cases carrying a better prognosis.

Search for peritoneal gas in rabbits with severe depression If found, this is an indication of rupture of the intestine and indicates euthanasia. Remember euthanasia always an option

Serial radiographs (every 30 – 90 minutes) looking for gas in hindgut. If gas in hind gut this indicates that the obstruction is moving - administer NSAIDs (carprofen or meloxicam) if not already administered (see above) - followed by prokinetics if still anorectic after 2-3 hours.

Fluid accumulation in stomach leads to deficit in intra- and extra-cellular compartments. Parenteral fluids required. Give Hartmann’s/kg /hr IV.

Exploratory surgery may be attempted. Decision of whether to embark on surgery or conservative treatment depends on the time of presentation and on financial considerations:

  • Day => conservative treatment
  • Night => surgery more likely

Surgical Procedure

  • Insert stomach tube to decompress: if it blocks, remove, flush and replace
    • Procedure of gastric decompression
      • +/- sedation
      • mouth to last rib
      • gentle gastric massage
      • patience
      • minimal suction
      • intermittent retropulsion
      • if tube is placed inadvertently endotracheally there will be
  • a change in breathing pattern
  • the presence of breath sounds at the free end of the tube
  • intraluminal condensation
  • Gastric rupture => euthanasia
  • Intestinal rupture => euthanasia
  • Intestinal neoplasm => euthanasia
  • Intestinal FB milked through ileocaecocolic junction into the hind gut or perform an enterotomy.
  • Note small omentum so omentalisation may not be possible
  • Postoperatively give antibiotics, prokinetics, food (force fed with Oxbow Critical Care Formula and baby cereal)

Practical approach to exploratory laparotomy in rabbits with intestinal obstruction

  1. Opiate premedication, oxygenation, gastric and tracheal intubation and isoflurane maintenance.
  2. Incision midline, sternum to umbilicus
  3. Inspect retroperitoneum for fluid/ingesta
  4. Palpate stomach and descending duodenum
  5. Palpate ascending duodenum (under caecum)
  6. Palpate jejunum cranially and caudally
  7. Look for flattened intestine caudal to obstruction
  8. Examine site of obstruction for contributive or subsequent pathology: cytology/biopsy?
  9. Milk obstruction to hindgut or stomach
  10. Gastrotomy/enterotomy/ectomy???
  11. Closure with Vicryl (not catgut)

Complications of rabbit intestinal surgery

  • Insufficient omentum for omentalisation
  • Intestine small and thin-walled
  • Food cannot be withheld during post-operative period
    • danger of hepatic lipidosis

Postoperative care

  • Warmth, quiet
  • Fluid therapy
  • Analgesia
  • Antibiotics
  • Prokinetics
  • Food (grass, dandelions)
  • Gavage with Oxbow CCF and Baby cereal


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References

  • Deeb, B. (2000) Digestive System and Disorders in Manual of Rabbit Medicine and Surgery, ed. Paul Flecknell pub BSAVA Cheltenham Glos Pages 39 - 46
  • Harcourt Brown, F. M. (2007) Gastric dilation and intestinal obstruction in 76 rabbits. Veterinary Record, 161, 409 – 414
  • Harcourt Brown, T. R. (2007) Management of Acute Gastric Dilation in Rabbits. Journal of Exotic Pet Medicine, 16, (3) 168 – 174