Equine GI Surgery 1

Question 1

What is colic?

Answer 1

A symptom - abdominal pain.
- mostly GI origin.
- peritoneal.
- URT.
- splenic pain.
- hepatic pain.
- repro organ pain.
- generalised, multifactorial.
- radiating pain.
Presentations of colic variable.

Question 2

What behaviours may horses with colic show?

Answer 2

Rolling.
Pawing at ground.
Looking at belly or flank.
Laying down/recumbency.
Kicking up at belly and out.
Agitated/restless.
Reluctance to perform.
Sweating — severe cases.
Stretching.
Head down.
Anorexia.
Yawning.
Urination.

Question 3

Investigating colic - “the P’s of colic”.

Answer 3

Pain.
Progression.
Pulse - quality and rate.
Pass a tube.
Palpate per rectum.
Peritoneal fluid.
PCV.
Pyrexia.
Per abdominal ultrasound.

Question 4

Investigating colic - the body systems.

Answer 4

GI - for indicators of nature and site of problem.
CV/respiratory - for indicators of severity of systemic disturbance produced by GIT problem.

Question 5

Investigating colic - taking a history.

Answer 5

Gauge history according to client and horse in front of you.
Comprehensive general background (if appropriate):
- BIOP.
- Normal use and routine.
- recent changes — housing, exercise, diet, competing.
- prophylaxis — dental (esp. in donkeys), vaccination (tetanus important for surgery).
Colic-specific:
- time last seen normal?
- time 1st colic signs?
- signs of pain.
- progression.
- treatment so far.
- response to treatment.
- when last DUDE.

Question 6

Investigating colic - core basic parameters.

Answer 6

HR, pulse quality, RR and effort/nature, temperature, MM colour and CRT, abdo auscultation and percussion, rectal palpation?, NG reflux (pass a tube)?.

Question 7

Investigating colic - extra parameters / explorations.

Answer 7

Rectal palpation?, NG reflux (pass a tube)?, haem/biochem (PCV and TP or percentage dehydration), per abdominal U/S, abdominal paracentesis, gastroscopy, ex lap.

Question 8

1. Why might HR increase in a horse with coli.
2. HR ranges and reasons.
3. Pulse qualities and reasons.

Answer 8

1. Pain.
   Shock.
   Congestion (reduced VR).
   Dehydration.
   Stress.
   Compensating for pH disturbance.
2. 20-40 - normal.
   40-60 - mild pain.
   60-80 - pain with like circulatory collapse.
   80+ - likely surgical.
3. Hyper-metric bounding — circulatory shock.
   Weak thready pulse — circulatory failure.

Question 9

Reasons for respiratory rate increases.

Answer 9

Pain.
Attempt to correct metabolic disturbances.
- run blood gas if available.
WATCH EFFORT TOO!

Question 10

Body temperature and colic.

Answer 10

Horses don’t tend to run a fever within colic.
May be a mild pyrexia due to pain.
Marked pyrexia with infection:
- e.g. Salmonellosis.
- e.g. aspiration pneumonia.
- e.g. peritonitis.
Hypothermia in profound circulatory shock.

Question 11

MMs and colic.

Answer 11

Colour:
- salmon pink = normal.
- red = congested or circulatory shock,
- purple rings = endotoxaemia (terminal).
- pale = anaemia (unlikely) — esp. cyathostome involvement.
CRT:
- <2 sec normal.
- >2 sec circulatory compromise.

Question 12

Abdominal auscultation when investigating colic.

Answer 12

Assess all 4 abdominal quadrants.
Increased sounds = hyper-peristalsis/spasm.
Decreased sounds = hypo-peristalsis.
No sounds = ileus.
Tinkling = tympany - look at size and shape of horse in case of bloat.
“Toilet flushing” = caecal emptying.
- right dorsal.

Question 13

Rectal palpation when investigating colic.

Answer 13

Thorough exam of caudal abdomen.
Important to know normal anatomy.
Identify pathology including:
- distended SI — “sausages”.
- impaction — often at pelvic flexure.
- displacement — taenial band orientation.
- tympany — taught, balloon-like.
- mesenteric mass/other masses.

Question 14

Where per rectum can you palpate the pelvic flexure of the horse?

Answer 14

Left ventral quadrant.

Question 15

Considerations for rectal palpation if the colic patient.

Answer 15

Indications.
Rectal safety - vet, horse, handler.
Minimising risks.
Normal findings.
Abnormal findings.
Subsequent actions.

Question 16

NG intubation in the colic patient.

Answer 16

Normally get 1-2L.
- anything over this is abnormal.
— large quantity of discoloured and malodorous fluid is indicative of SI obstruction.
— large quantities of brown and very odorous fluid is dire.
Also releases gas.
Decompression helps to reduce pain.
CAN BE LIFE SAVING IN THE SHORT TERM!

Question 17

Haematology and biochemistry in the colic patient.

Answer 17

PCV/TP - 31-43% = normal.
- 53-73 g/dl = normal.
— to be interpreted in light of individual horse.
— both elevate with dehydration and shock.
Lactate in the circulation
- demonstrates tissue ischaemia.
- <1mmol/L = normal.
Blood gas
- before or during GA to identify acidosis and electrolyte disturbances.
Basic profile
- if suspect alternative or concurrent pathology.
- e.g. WBC or muscle / liver enzymes.

Question 18

1. Abdominal ultrasound of the colic patient.
2. Where can you visualise the duodenum in the horse?

Answer 18

1. Useful to determine:
   - gut position — entrapment?
   - gut wall thickness.
   - gut distension.
   - gut motility.
   - gut content.
   - free fluid.
2. Right dorsal quadrant.

Question 19

1. Abdominal paracentesis of the colic patient.
2. Normal sample appearance?
3. Amber/orange indicative of?
4. Red/black indicative of?
5. Gut content in sample indicative of?
6. Transparent/clear?
7. Opaque/cloudy?

Answer 19

1. At ventral midline.
   Sterile prep.
   4 inches caudal to sternum or most dependent part of abdomen.
   Either use a test cannula with LA (25G needle) and stab into linea alba (11 blade).
   OR
   18G and 2 inches long needle (go off to side to miss the spleen).
   Catch fluid in EDTA and plain to send some for white cell count and cellularity and some for culture.
2. Transparent, straw-coloured, clear.
3. Vascular compromise.
4. Necrosis.
5. Rupture or accidental lumen penetration during abdominal paracentesis.
6. Acellular.
7. Cellular.

Question 20

1. Normal TP of abdominal fluid.
2. Normal complete cell count of abdominal fluid.
3. Normal lactate levels in abdominal fluid .
4. White cells and their normal percentages in abdominal fluid?

Answer 20

1. <20g/L.
2. < 2x10^9 cells/L
3. <2mmol/L.
4. 20-90% polymorphonuclear neutrophils.
   5-60% mononuclear and mesothelial.
   0-35% lymphocytes.
   0-5% eosinophils.

Question 21

Failure to achieve a diagnostic sample
- problems and solutions.

Answer 21

Dehydration - rehydrate and repeat.
Splenic tap - use U/S guidance.
Extensive fat layer - U/S and long cannula.
Enterocentesis - consider U/S.
Not penetrated peritoneum - sharper movement needed.

Question 22

Gastroscopy.

Answer 22

Useful in cases of gastric impaction.
Particularly in recurrent or chronic colic cases.
May evidence gastric ulceration:
- significance doubtful if single episode.
- more likely significant of chronic recurrent case.

Question 23

Exploratory laparotomy.

Answer 23

Diagnostic tool and treatment tool.
- allows to confirm aetiology and hopefully manage it

Question 24

“Good” findings that indicate a case that can be managed medically.

Answer 24

Only mild/intermittent behavioural signs.
Some faeces passed.
HR < 50.
Normal pulse quality, MM colour, CRT.
Gut sounds present on auscultation.
Rectal - NAD and no palpable impaction.
Normal PCV, protein, lactate on bloods.
No reflux with NG tubing.
U/S normal with no distended SI.
Normal peritoneal fluid on paracentesis.

Question 25

“Bad” findings that may suggest a case needs surgery.

Answer 25

Moderate-severe and persistent behavioural signs despite analgesia. No faeces passed. HR >60. Poor MM colour. Reduced or no gut sounds on auscultation. Distension +/- displacement of intestine (SI or LI) on rectal exam. Increased PCV, protein, lactate. Positive reflux on NG intubation w/ >5L net. U/S shows distended SI or displaced LI. Discoloured and turbid peritoneal fluid on paracentesis.

Question 26

Considerations for the owner before emergency colic referral.

Answer 26

Cost - likely £4000-£10,000. - insurance limit £3000-£5000 commonly. - may need to pay up-front. - chance of being unsuccessful. - may need revision surgeries. Transport. Prognosis - duration of signs critical. - severity of systemic disturbance also gives clues. Complications are variable, many and common. - need to be aware of these before signing consent form. Duration - likely 1-2hrs surgery. - likely 1-5 days ICU and 6-15 days hospitalisation.

Question 27

Reasons for euthanasia of colic patients.

Answer 27

Many reasons for euthanasia before, during and after surgery. These may change with time. Financial constraints. Poor prognosis. Perceived need for additional surgery. Repeat colic episodes. Post op complications. Concurrent issues. Anticipated behaviour non-compliant for box rest. Other perceived viability - age does not impact survival!

Question 28

Referring colic cases from practice.

Answer 28

Build good relationship with local referral hospital. - get to know who is there and how they work. To refer emergencies: - phone call while still with client. - clearly present Hx and clinical findings, drugs administered, incl. time and case progression. — agree on other drugs they may like you to give. - Estimate ETA — load and travel time, — remember to decompress prior to travel if SI lesion (may leave NG tube in situ). — ensure sufficient analgesia to travel safely —> flung is great, sedation too. They will repeat much of exam before surgery unless violent behaviour . Expect a call after surgery or following morning with an update.