Disease of the Caecum & reperfusion injury Flashcards
what side of the abdominal cavity does the caecum lie on
RIght abdominal wall - between ileum & ventral colon
what is the volume of the caecum
30L
what is the Haustrae
The caecum has 4 bands of smooth muscle (taenia) which form pouches know has the haustrae
it is responsible for mixing contents and delays transport
What is responsible for caecal motility
Pacemaker in ventral caecal wall, 10-15cm from apex - generates the neural impulses that cause caecal motility
what are the two types of contractions of the caecum
- segmental contraction: mixes ingesta; mainly towards the apex
- Progressive contractions - large caecal segements contract at 3-5 minute intervals, produces mass movements which force the caecal content into the colon
What factors inhibit the contraction of the caecum
Alpha agonist (xylazine, detomidine) & opioids
what factors stimulate the contraction of the caecum
Parasympathominetics (neostigmine, bethanechol, erythromycin)
What are the functions of the caecum
- water reabsorption
- Electrolyte resorption (na, Cl)
- initiates microbial digestion of complex carbohydrates (fibre)
what is the most common caecal disease
Caecal impaction (40-50%) Dehydrated faecal material accumulating at caecal BASE
What are the risk factors for caecal impaction
Hospitalization/surgery - esp MUSCULOKELETAL & OPTHALMOLOGY CASES poor dentition poor quality hay/access water Parasites - thromboembolism Anoplocephal perfoliata
what are the Cs of caecal impaction
often very mild & intermittent colic - Hr normal to slight increase
May rupture caecum with no significant signs of abdominal pain
Decreased faecal production
Decreased borborygmi
How do you diagnose caecal impaction
RECTAL PALPATION
- tight ventral caecal band palbale on RIGHT side of the abdomen
ABDOMINOCENTESIS - Normal
What medical txm can be used for caecal impaction
provide analgesia
NGT if relfux due to concurrent SI distension
Softens digesta (laxatives)
Prevent further caecal filling - withhold feed
Motility stimulants not used as may potentiate rupture
Address any risk factors
what is the surgical options for a caecal impaction
Typhlectomyn
Caecocolostomy, Jejunocolostomy
what is Caecal tympany
Gaseous distension of the colon
what is primary caecal tympany
Rapid gass production (lush pasture, high grain diets) or reduced caecal motility
what us secondary caecal tympany
More common
Outflow obstrcution aboral to caecum (i.e colon displacement)
what are the Cs of caecal tympany
Abdominal distension (1 R flank) intermittent ==> severe pain tachycardia tachypnoea decrease borborygmi Abdominal percussion: PING R DORSAL FLANK
what is a clinical path finding that can reflect primary caecal tympany
Corticosteroid (stress) leukogram
what is the txm for caecal tympany
Visceral analgesia -Xyalazine Gastric decompression fluid therapy: IV +/- NGT laxatives withold food surgica; decompression trocarisation if severe but beware as risk of leakage, peritonitis, cellulitis
what is the difference between primary and secondary caecal perforation
primary = broodmares after parturition without evidence of caecal outflow obstruction
secondary (more common) - caecal outflow obstruction
Rupture of caecal base most common with relatively empty ventral colon and ingested filled caecum
what is the main risk factors for caecal intussusception
tapeworm infestation
How do you diagnose caecal intussusception
adbominocentesis; normal if acute ==> serosanguineous as disease progressed
clin path; normal ==> dehydration & metabolic acidosis
ULTRASOUND: THICKENED CAECAL WALL (‘DOUBLE DONUT’)
what is a reperfusion injury
Damage to tissue caused when blood supply returns to tissue after a period of ischaemia
