Colic - LI Flashcards
Where is the large intestine attched to the body wall? (2)
- Caecum
- Right dorsal colon
What shape does the large colon form in the abdomen?
U - shape
What allows the entire large colon to move, twist or displace?
The lack of attachments
What presents a site for formation of LI impactions?
The anatomical 180 degree bend
How many taenia bands does the RDC have?
3
What can altered intestinal motility patterns cause? (2)
Localised impaction, or anatomic displacement
Large colon diseases can be grouped together as the are likely to have a similar aetiopathogenesis, what can these be denoted as?
SCOD
Simple colonic obstruction and distension
Define SCOD
Effectively SCOD is all forms of large colon disease except those causing vascular obstruction
Group together impactions and distensions
Intestine doesn’t die just compromised
Ultimately the colon is healthy
Name risk factors for SCOD (8)
- crib-biting/wind-sucking
- stabling 24 hours per day
- history of travel in previous 24 hours
- recent change in exercise program
- absence of use of moxidectin/ivermectin in previous 12 months
- increasing hours in stable
- history of previous colic episode
- less regular dental care
What is the major difficuty of reassuring yourself when you have a pelvic felxure impaction?
Reassue yourself there are no other anatomic displacements
What does a pelvic felxure impaction feel like?
Doughy/raltively firm – too much ingesta and cant move through properly.
How can you medically manage a pelvic flexure impaction?
Pain relief, a small number cant be managed so will need surgery where everything is essentially emptied out
When do secondary pelvic flexure impactions occur?
To sequestration of fluid in the small intestine in.
Name 3 things which cause secondry PF impaction (4)
–Ileal impaction
–Anterior enteritis (infectious)
–Equine grass sickness
–occasionally in other strangulating lesions depending on duration of clinical signs
What is actually happening in a secondary PF impaction?
•The fluid is stuck and the fluid has never got to the colon where it is to be absorbed
What is this?
Primary PF impaction– huge amount of ingesta
All food material built up
Dough like
What is this? What would it feel like?
Secondary PF impaction – grass sickness Fluid not getting through. Colon can do its job, just no more fluid going in
Shrink wrapped ingesta
How can we treat a PF impaction?
•Generally treatment consists of hydration of the impacted ingesta to soften and allow the body to move it on
–Most easily achieved by nasogastric intubation of fluids
–Aim to exceed to absorptive capacity of the large intestine. So need to put in more than the 4 litres needed.
How much of the ileal outflow does the caecum absorb?
70%
What is the effect of paraffin?
Facecal softening
What is the risk of administering paraffin?
Inadvertently administering paraffin into the trachea will kill a horse (slowly and distressingly)
What is the main benefit of using paraffin?
Hint: If you see oil staining
If you see oil staining around the tail you know the horse is passing something
The colon single point of fixation of the colon allows it to move freely within the abdomen, what may this result in? (3)
–left dorsal displacement (nephrosplenic entrapment)
–simple left colon displacement (retroflexion of the pelvic flexure)
- Twist back on itself
- Absence of the PF
–right dorsal displacement
- Colon between the caecum and the right body wall
- Spleen may be moved abaxially
What are the clinical signs of a displacement? (5)
- Abdominal distension (especially on the left for left dorsal displacement)
- Reduced gut sounds - things aren’t moving like they should
- Varying degrees of pain
- Usually cardiovascularly stable
–We haven’t killed any guy. No anaeorobic respiration
–Normal PCV, lactate etc.
•Heart rate often normal even when relatively severe signs of pain
How can you treat displacments?
•Generally medical treatment is attempted initially
–usually pain is the indication for surgical management to correct
•Cant keep them in pain
–treatment methods will be discussed further in the practical session tomorrow
What is the prognosis of a displacement
Generally very good; however, there is a possibility that some horses may be predisposed to displacement-type colics
What is one of the most catastrphic colic lesions?
LC volvulus
What is essential with a LC volvulus?
•Early diagnosis and referral essential for survival
–Don’t do quick enough = die or a large colon compromise
What happens with a LC volvulus?
•Usually entire large colon twists around long axis, involving both dorsal and ventral colons
Involves both as they are stuck together
What is the risk of transporting a LC volvulus?
Colic really bad = more injuires e.g. fractures
Where is there a higher incidence of LCV?
Older mares
What are the 3 different degrees of torsion with a LCV?
–180° torsions present similarly to other displacements (gut just flipped over)- not ischaemic or vascular compromise. Pain is from the gas. Manage medically and hope for it to untwist
–Greater than 360° causes complete obstruction and vascular compromise
•Vascular compromise – start the timer as the gut is dying
–270° torsion generally implies a complete rotation but no vascular compromise
•Gone 360 degrees, unravelling it has meant that the gut hasn’t died. So a full rotation just not dead (needed a name less than 360 but more than 180)
What are the clinical signs of a LCV dependant on?
Degree of torsion
What are the clinical signs o an LCV torsion greater than 270°? (4)
–Severe, uncontrollable pain
–Signs of vascular compromise (tachycardia, dehydration, congested mucous membranes)
–Abdominal distension
–Rectal exam: distended, tympanitic, oedematous large intestine, abnormal position and taenial bands
What is the roblem with a 360 degree LCV?
What pre op treatment should we give for LCV?
•In most cases immediate surgery is required therefore focus is on analgesia and arranging immediate transportation
–similar situation at the referral practice
–best way of improving cardiovascular status is to relieve distension and pressure on diaphragm
How do you approach surgical treatment ofa LCV?
- Standard midline laparotomy incision
- Correct torsion
Distended and heavy (40kg) – need to get to the normal position
Try and get as light as possible (evacuate) – work out where the twist is and get in the normal position
What do we do if the bowel is non viable with a LCV?
- If bowel is non viable at surgery horse will be euthanased
- Colon resection is possible, but rarely performed in the UK, due to the population we have. They get to facilities too late.
Whats the risk with this?
Moderate compromise – but thick
What should we do with this?
Needs euthanasing
What is the post operative care for LCV?
- As for small intestine
- Particular care over hydration and serum protein
What may require plasma transfusion with LCV?
Severe protein loss through compromised bowel and endotoxaemia
Complications for LCV are as for SI surgery but name 2 in particular(4)
–SIRS, diarrhoea/colitis, laminitis, hypoproteinaemia
What is the prognosis for a 360degree LCV?
What is survival directly correlated with?
•Generally prognosis for 360° torsions is poor
–survival directly correlated with cardiovascular status before surgery
–epidemiological data shows that horses suffering from strangulating torsions are at a much higher risk of developing post-operative colic - as you cant take it out
–often present the most challenging cases of colic post-operative care
–important to maintain honest assessment with owner
How are caecal disease identified
Rectal exam
Name 3 caecal disease (4)
–impactions; a serious concern, often seen in orthopaedic patients following box rest
–intussusception, usually younger horses; high association with tapeworm burden (may not feel this exactly but will feel changes)
–local infarction
–often also involved in large colon torsions
What is the prognosis for caecal disease requiring surgery?
Poor
–unless there is no ischaemia
–or if there is focal ischaemia of the caecal apex
Why is caecal impaction such a major concern? (3)
–Failure of treatment may lead to caecal rupture
–Often not diagnosed until late in the disease course
–Clinical indicators of caecal impaction often relatively non-specific
Are small colon disease more or less common?
Less
What small colon disease may be seen? (3)
–can be strangulated by lipomas
–can become impacted (remember meconium impactions on foals)
–intussusception also occurs (small colon may become exteriorised in Grade 4 rectal prolapse)
What is the presumptive cause of colic in miniature ponies and horses? why?
–small colon impactions are often a presumptive cause of colic in miniature ponies and horses (too small to rectal to confirm diagnosis)
What is the prognosis of small colon compared to large intestinallesions?
Surgical prognosis excellent compared to other LI lesions
