Colic - Medical Management

Question 1

What are the following parameters for medical?

1. Degree of pain/response to analgesia
2. Heart rate
3. CRT
4. MM colour
5. Borborygmi
6. Peritoneocentesis
7. TP/colour
8. PCV/TP/Lactate concs
9. Recovery from nasogastric intubation
10. Rectal findings

Answer 1

1. Mid-low pain
2. Responds to analgesia
3. <60
4. <2
5. Normal
6. Present
7. Normal
8. Normal
9. <3-5L fluid
10. Disease dependant – mildy abnormal

Question 2

What are the following parameters for medical?

1. Degree of pain/response to analgesia
2. Heart rate
3. CRT
4. MM colour
5. Borborygmi
6. Peritoneocentesis
7. TP/colour
8. PCV/TP/Lactate concs
9. Recovery from nasogastric intubation
10. Rectal findings

Answer 2

1. High pain
2. No response to analgesia. Depending if pony/donkey/cobb/native breed – stoic (rely on clinical signs)
3. >60
4. 3-4
5. Dark pink (maybe toxic rings around teeth). Congested
6. Absent
7. Serosanguinus
8. Increased TP
9. Increased (lactate >5)
10. TP> 30
11. >5L
12. Abnormal

Question 3

Name 5 exceptions for how you expect colic to act. (7)

Answer 3

• Grass sickness (equine dysautonomia) – high HR (high nasogastric reflux). Alwayss above 60
• Anterior enteritis – high HR and large volumes of NG reflux. Common in other parts of the world.
• Colitis – usually severely hypovolaemic (high HR). Will look like surgical colic. Dark red MM.
• Peritonitis – high HR and hypovolaemic
• Spasmodic colics - can be very painful, often intermittent. Normally respond to analgesia (not always)
• Epiploic foramen entrapments – normal rectal findings. SI gets stuck a long way forward between foramen (stomach and liver). Normal rectal findings as distended is further forward.
• Ponies and donkeys – very stoic, beware

Question 4

Which horse should you refer and where should you refer?

Answer 4

• Surgical cases
• Severe colitis
• Grass sickness (chronic)
• Any horse the client wants you to refer
• Medical cases which need a lot of care

–In an ideal world – refer to a local clinic with appropriate specialisation.

–Depends what it is – relatively local but to the right person

Question 5

How are we going to initially manage a horse with colic?

Answer 5

–Manage pain

•Analgesia – NSAIDs, Opioids, Hyasine (anti-spasmodic not a true analgesia but will help reduce contractions)

–Prevent deterioration

Question 6

What NSAIDs can we use and what are the effects? (3)

Answer 6

• Phenylbutazone – NEED passport
• Flunixin meglumine – won’t affect HR, gut sounds and mm (hypovolaemia). No evidence anti toxin. May mask surgical pain.

–Can use a lower dose if unsure

•Carprofen/meloxicam - £££

Question 7

Name 3 anti-spasmodics (4)

Answer 7

• Butylscopolamine (hyoscine butylbromide) +/- metamizole (works for about 20 minutes)
• Pethidine (only lasts about an hour). Licensed for spasmodic colic
• Buprenorphine
• (Methadone – on cascade, licensed in dogs)

Question 8

What are the alpha 2 agonists?

What are the properties?

Why might you administer this?

What are the benefits?

What are the pitfalls?

Answer 8

•Xylazine/Detomidine/Romifidine

–None licensed in colics but are necessary

–Longest acting - romifidine

–Shortest acting – xylazine

–Give IV to act quickly. If we wanted it to last could give IM larger dose

•What properties do these drugs have?

–Analgesic & sedative

•Why might you administer these?

–Transport

•What are the benefits?

–Very painful horse hard to manage

–Analgesia

–Reduce heart rate – but wont in a hypovolaemic patient!!

–Reeduce gut motility

–Can use in CV collpase

•What are the pitfalls?

–Make them wee! Bad if dehydrated

–Not licensed in colic

Question 9

What opioids can we use?

Answer 9

•Butorphanol a poor analgesic and quite expensive when used at ‘analgesic dose’ – 10 times the ‘sedative dose’

–expensive

Buprenorphine – good analgesia to keep in the car.

• Boluses or infusions of morphine (or methadone*) occasionally useful in a referral environment
• * now has SA license – but not as good re PK/PD as morphine for use in CRI’s

Question 10

• What are the indications for administering fluids?
• What routes can you use?
• When would you not use oral fluids?
• What conditions are oral fluids particularly valuable for?

Answer 10

•What are the indications for administering fluids?

–Hypovolaemia, dehydrated (rare in colic), large colon/caecal impactions

•What routes can you use?

–Enteral, oral, IV, per rectum

–IV – hypovolaemia

–Oral – impaction

–Per rectum – well absorbed but on going work

•When would you not use oral fluids?

–Surgical lesion, ileus, lots of NG reflux, >5% fluid deficit

–Obstruction in the small or large intestine

–Really hypovolaemic – oral fluids, the first place the blood comes from is the GI tract so the fluids wont be absorbed

•What conditions are oral fluids particularly valuable for?

–Large colonic impactions in horses that aren’t hypovolaemic

–Pelvic flexure

Question 11

•NB Horses are not labradors and do not weigh 30 Kg!

–If IV fluids are indicated it is important to try to accurately calculate how much fluid deficit is present. If the horse has to be transported then you need to give fluids. If the referral is close just get them there

–What are the maintenance requirements for an adult horse and foal? How much fluid is that for a 500Kg TB?

–How much fluid is required to replace a 10% deficit in a 500 Kg TB?

Answer 11

–What are the maintenance requirements for an adult horse and foal? How much fluid is that for a 500Kg TB?

• 2ml/kg/hour – adult
• 5ml/kg/hour – young. Made of more fluid so need more
• ~1L/h

–How much fluid is required to replace a 10% deficit in a 500 Kg TB?

•50L (plus maintenance)

Question 12

What is the relationship between exercise and colic?

Answer 12

•Commonly recommended in cases with minimal pain

–e.g. mild large colonic tympany palpable on rectal examination

–Horses with left dorsal displacement (nephrosplenic entrapment) and RDD if not too painful

–Horses can be lunged assuming they have received appropriate analgesia

–Spasmodic colic, displacement (assuming no tight taenia bands)

–DO NOT RECOMMEND OWNER TO WALK UNLESS YOU’VE SEEN

• DO NOT walk horses with severe colic
• Put in deep bedded box and keep quiet

Question 13

•What conditions may cause ileus in the horse and why?

Answer 13

–SIRS, dead gut, kink in SI, inflammation in bowl wall, peritonitis, lack of feeding, trauma in surgery (not careful or slow surgeons), stress, pain

–In horses we starve post surgery – this is something which we may need to change

–Adult horses don’t get cold in surgery like bunnies

Question 14

How do we diagnose ileus?

Answer 14

–Absence of (or very few) gut sounds (low borborygmi), US (absence or non-progressive motility), high HR, pass NGT (fluid back implies no motility), low faecal output

Question 15

How can we manage horses that have ileus secondary to peritonitis?

Answer 15

–Anti-endotoxin drugs (e.g. Polymixin B), BS ABs, put drain into abdomen and lavage (~10L at a time)

–Abdominal lavage

Question 16

•How can we manage horses with post-operative ileus or how can we prevent the development of ileus?

Answer 16

–Try and get them to eat (small amounts of grass), analgesia, prokinetics

Question 17

Discuss the pro-motility agents (4)

Answer 17

•Lidocaine (analgesic & prokinetic)

–Lidocaine IV - blocks inhibitory SENSORY neural pathways thereby inhibiting sns inhibitory activity, and perhaps more importantly appears to have anti-inflammatory properties. The side effects of lidocaine administration are muscle fasciculations and ataxia.

•Metaclopramide (dopamine receptors)

–Has to be CRI (only lasts ~20m)

–Neurological side effects

–Metaclopramide – dopamine receptor blockade, cholinergic stimulation and adrenergic blockade. Gastroduodenal junction and along entire si. Metoclopramide does have some clinical efficacy, but the neurological side effects, including hyperexcitability and agitation, can be a problem. Although these can be rapidly reversed by decreasing the rate of metoclopramide administration (it should also be given as a CRI) and sedation, horses on this medication require very close monitoring. Minimally effective when used as boluses in horses

•Erythromycin (motilin receptors)

–Maybe better for LI motility disorders

–Erythromycin is administered at the sub-therapeutic antibiotic dose of 0.5-1mg/kg in 1L saline, infused over 60-minutes, and repeated every 6-hours. The most frequent complication is colic, although there are also some reports of diarrhea. Acts on motilin receptors. Distal si, caecum and pelvic flexure

•(Neostigmine acetylcholine esterase)

Question 18

What factors may predispose horses to colic? (8)

Answer 18

1. Change in diet
2. Changes in housing/managament
3. State of teeth – have they been rasped?
4. Parasites- do they have a high worm burden?
5. Seasonality (not grazed in winter)
6. Stable-vices
7. Previous history of colic or surgery
8. Stress

Question 19

What are the survival rates of:

A) Strangulating lesions?

B) LI displacements?

C) LI Torsions?

Answer 19

A) 60-80%

B) &0-85%

C) 25-50%

Question 20

• 6 year old TB brood mare that foaled 4 weeks ago
• Acutely painful for last 90 minutes

–Wall of death around stable

–Sweating

–Pawing

–Rolling

• HR=100 BPM, CRT 4 secs, MM dark pink and tacky
• No borborygmi
• No reflux
• Could not perform peritoneocentesis
• No ability to perform blood gas/PCV/TP

Do you think that this horse has a medical or surgical form of abdominal pain?

How would you try to facilitate rectalling this horse?

Rectal exam revealed a large distended viscous in the pelvic inlet that had palpable taenial bands and resulted in pain when manipulated. What might this be?

What analgesic regime would you attempt to use in this case?

Answer 20

•Do you think that this horse has a medical or surgical form of abdominal pain?

–Surgical

•How would you try to facilitate rectalling this horse?

–Sedation (IM + IV)

•Rectal exam revealed a large distended viscous in the pelvic inlet that had palpable taenial bands and resulted in pain when manipulated. What might this be?

–Colon torsion (brood mare)

•What analgesic regime would you attempt to use in this case?

–Needs to get to referral centre (30m away)

–Flunixin

–Detomidine

–Pethidine/buprenorphine

Question 21

• 10 year old Cob gelding
• Horse has recently been purchased and has no worming history and last had his teeth rasped 2 years ago
• 2 hours of intermittent colic

–Rolling

–Pawing

–Flank-watching during the times he is up

• HR=48-65 BPM, CRT <2secs, MM pink
• Increased borborygmi in all quadrants – you can hear them without your stethoscope
• You decide not to perform NG intubation and peritoneocentesis

Do you think that this horse has a medical or surgical form of abdominal pain?

• How could you manage this horse so that it is safe to rectal?
• Rectal exam revealed a large distended viscous beyond the pelvic inlet that had palpable taenial bands. What might this be and what are the differentials?
• What management changes and analgesic regime would you attempt to use in this case and why?

Answer 21

•Do you think that this horse has a medical or surgical form of abdominal pain?

–Medical

•How could you manage this horse so that it is safe to rectal?

–Sedate

•Rectal exam revealed a large distended viscous beyond the pelvic inlet that had palpable taenial bands. What might this be and what are the differentials?

–Spasmodic colic

–Displacement

•What management changes and analgesic regime would you attempt to use in this case and why?

–Rasp teeth

–Check diet

–Worm horse (moxidectin + praziquantel) +/- FWEC

–Buscopan

–NSAIDs

Question 22

• The horse that we discussed in the last lecture (case 1) had a strangulating SI lesion due to a pedunculated lipoma.
• At surgery 25 feet of SI were resected and an anastomosis was performed

How can you manage this case post-operatively?

What regime could be implemented to try and prevent ileus and how will you evaluate the animal to check that he doesn’t have this condition?

Answer 22

Management:

–ABs (penicillin, gentamycin)

–Analgesia (flunixin)

–Fluids

–Stomach tube

–Polymixin (anti-endotoxic)

–SC heparin (to prevent microthrombi)

Regime:

–Lidocaine (for prokinetic properties)