Colic critical decision making and case management Flashcards
Decisions
▪ What sort of treatment is required?
→ medical
→ surgical
→ euthanasia
▪ Where should treatment / management take place?
→ at home
→ at a veterinary clinic / surgical facility
▪ Decisions can be changed (apart from euthanasia)
Influencing Factors for decision making
▪ Cause / severity of colic
▪ Prognosis following treatment
▪ Finances / insurance cover
▪ Owner’s wishes
▪ Availability & ease of transport
▪ Intrinsic factors e.g. age, concurrent disease
Conditions that always require medical management
- Spasmodic colic
- Gaseous colic
- Anterior enteritis
- Colitis
- Gastric ulceration
- Grass sickness (ileus)
Conditions that are sometimes medical, sometimes surgical
- Colon displacement
- Colon impactions (ingesta/sand)
- Peritonitis
- Non-GI lesions (e.g. kidney dz)
- SI simple obstruction
- Parasites
Conditions that are require surgical tx (or euthanasia)
- SI/small colon incarceration
- SI/small colon volvulus
- Colon torsion
How do we assess colic severity / achieve diagnosis?
1) History
2) Pain level and response to analgesia
3) Mucous membrane colour and capillary refill time – perfusion
4) Hydration status
5) Heart rate & pulse strength
6) Respiratory rate
7) Gut sounds
8) Abdominal distension
9) Temperature
10) Rectal findings
11) Volume of naso-gastric reflux
12) Abdominal fluid analysis
13) Ultrasound findings
14) Blood analysis
Not all diagnostic tests will be used in every case
History
▪ Signalment – age, breed, sex (stallion), pregnant, recently foaled?
▪ Normal management / feeding?
▪ Recent management / feeding changes?
▪Duration of signs?
▪ What behaviours have been occurring?
▪ Progression – improving / deteriorating?
▪ Previous colic incidence?
▪ Passed droppings today / last few days? Normal number & consistency?
▪ Concurrent disease?
▪ Recent medication (wormers)?
Signs of abdominal pain
- Standingquietly
- Reduced appetite
- Lip curling
- ‘Pained’ facial expression
- Restlessness
- Bruxism (teeth grinding)
- Pawing the ground
- Lookingatflanks
- Kicking at abdomen
- Repeatedly getting up and down **
11.Lying flat out or on back** - Rolling**
** = severe
Response to analgesia
▪ Response to analgesia is usually predictable.
– E.g. flunixin 1.1mg / kg should provide analgesia within 10 minutes and last about 12 hours.
▪ If colic signs do not improve following analgesia or return within a few hours something more significant is occurring.
Mucous membrane colour and capillary refill time
▪ Normal colour is ‘salmon pink’
▪ Normal capillary refill (CRT) is 1-2s
▪ Pale or dark injected membrane and prolonged CRT suggest poor peripheral perfusion
→ endotoxaemia? (esp if dark and injected)
Hydration Status
▪ Dry / tacky mucous membranes?
▪Prolonged CRT?
▪Prolonged skin tent?
▪ Not hugely accurate - a guide only
▪ Age affects skin tent
– Elasticity of skin decreases with age
Heart rate & pulse strength
▪ Elevated due to pain, toxic shock and dehydration
▪ Pulse may be weak and ‘thready’
– Facial artery pulse
▪ Transient heart murmur not uncommon with colic
– Due to flow disturbances in the CV system
HR 20-44 = normal
HR 44-60 = mild
HR 60-80 = moderate
HR >80 = severe
Respiratory rate
▪ Elevated due to pain or concurrent respiratory disease
RR 8-12 = normal
RR 12-20 = mild
RR 20-30 = moderate
RR >30 = severe
Gut sounds
▪ Gut sounds (borborygmi) occur constantly
→ Low grade constant grumbling – peristalsis in S.I. and colon
→ Caecal emptying 1-3x / minute – sounds like a toilet flushing
– Listen to RHS
▪ During colic, sounds may be normal, decreased or increased
▪ Listen in all 4 quadrants and grade separately
▪ Abnormal sounds may also be heard e.g. sand
Interpretation of normal gut sounds
- doesn’t mean the horse doesn’t have colic
Interpretation of increased gut sounds
- Guts are hypermobile, e.g. spasmodic colic
Interpretation of decreased gut sounds
- Guts are hypomobile e.g. colon impaction
Interpretation of absent gut sounds
- Guts are non-motile, e.g. SI incarceration
Abdominal distension
▪ Difficult for us to tell between fat / distended– ask owner
▪ May expand between examinations
▪ May get a ‘ping’ following abdominal percussion
▪ Indicates gas distension with large intestinal lumen
→ excess gas production or blockage passage of gas?
→ usually large intestine
Rectal temp of >37C (interpretation, relevance)
- hypothermic
- suggests CV compromise/shock
Rectal temp of 37-37.5C (interpretation, relevance)
- mildly hypothermic
- important in foals
- probably irrelevant in adults
Rectal temp of 37.5-38.5C (interpretation, relevance)
- normal
- doesn’t rule out colic
Rectal temp of 38.5-39C (interpretation, relevance)
- mildly hyperthermic
- may be due to pain
Rectal temp of >39C (interpretation, relevance)
- significantly hyperthermic
- suggests infectious/inflammatory condition
Rectal findings
▪ Normal rectal is soft and without tension or distension
▪ Abnormal findings include hard ingesta, gas distended intestines, abnormally
located structures and tight taenial bands.
▪Can palpate small intestine, caecum, large colon, spleen, ovaries, uterus, bladder.
Naso-gastric reflux (normal stomach content, max volume, what large volumes suggest)
▪ The stomach normally holds 2-3L of green non- malodourous fluid and will empty quickly after drinking.
▪ Larger volumes of fluid in stomach suggest S.I. obstruction
→ fluid backs up behind a blocked pipe.
▪ Maximum volume of horse stomach is 8-15L.
▪ Large volumes (>7-12L) foul smelling gastric fluid can be retrieved in small intestine is obstructed
Normal abdominal fluid analysis
Colour:
- Yellow
Clarity:
- Clear
Volume:
- Small
WBCc:
- <5000cells/µl
Total protein:
- <30g/L
Lactate:
- <2.5mmol/L
Compromised intestine abdominal fluid analysis
Colour:
- Pink/brown (serosanguinous)
Clarity:
- Opaque
Volume:
- Slightly increased
WBCc:
- Slightly elevated
Total protein:
- Slightly elevated
Lactate:
- Elevated
Ruptured intestine abdominal fluid analysis
Colour:
- Green/brown (ingesta)
Clarity:
- Opaque (can see food particles)
Volume:
- Large
WBCc:
- Elevated
Total protein:
- Elevated
Lactate:
- Elevated
Peritonitis abdominal fluid analysis
Colour:
- White/yellow
Clarity:
- Turbid
Volume:
- Large
WBCc:
- Elevated
Total protein:
- Elevated
Lactate:
- Elevated
Abdominal Ultrasound - Q’s to ask
▪ Peritoneal fluid – increased volume?
▪ Small intestine – motility, distended?
▪ Stomach – full of fluid?
▪ Colon – distended, displaced?
▪ Intestinal wall thickness – increased?
Blood analysis - PCV and TP
- increased in dehydration/shock
Blood analysis - WBC & differential
- increased or decreased in infectious processes (depending on time frame)
Blood analysis - SAA or Fibrinogen
- increased if inflammatory/infectious process present
Blood analysis - lactate
- increase if compromised bowel present
Blood analysis - electrolytes
- electrolyte abnormalities
Medical management (at home) for gaseous/spasmodic/idiopathic (mild) colic
▪ Analgesic – flunixin meglumine IV (Flunixin / Finadyne / Banamine)
▪ Spasmolytic – hyoscine butylbromide IV (Buscopan)
▪ No food but allow water
▪ Possibly oral fluids (isotonic electrolytes)
▪ Monitoring by owner
▪ Gradually return to normal diet the following day
▪Re-examination if doesn’t improve or colic recurs
Medical management (at home) of pelvic flexure impaction
▪ Analgesic – flunixin meglumine IV (Flunixin / Finadyne / Banamine)
▪ Oral laxative fluids (MgSO4 / liquid paraffin)
→ may be repeated later in the day
▪ No food but allow water
▪ Monitoring by owner
▪ Definite re-examination 12-24hrs later
→ still showing mild colic signs
→ has only passed 1 small dropping
→ impaction still palpable on rectal exam
Medical management (at clinic) of pelvic flexure impaction
▪ Analgesic – flunixin meglumine IV (Flunixin / Finadyne / Banamine)
▪ Oral laxative fluids (MgSO4 / liquid paraffin / water / isotonic electrolytes)
→ may be repeated up to 6 times during a day
▪ IV isotonic fluids (Hartman’s) at twice maintenance
▪ No food but allow water
▪ Monitoring by vets, nurses and students
▪ Regular re-examinations until:
→ large volume of faeces produced
→ colic signs resolve
→rectal exam confirm impaction has cleared
▪ Gradually return to normal feeding (and check the teeth)
– Soft food with short stem, e.g. grass or mashes if not grass season
Pre-referral management of SI obstruction / incarceration / strangulation
▪ Analgesia – flunixin & opiate (butorphanol) IV
▪ Spasmolytic - hyoscine butylbromide IV
▪ Sedation – long acting a2 agonist (detomodine / romifidine) IV +/- IM ▪Decompress stomach – reflux and possibly leave tube in place
▪ IV fluid bolus isotonic (Hartmann’s) or hypertonic (7% NaCl)
– Hypertonic good for bringing circulating volume up quickly, needs to be followed with isotonic
▪ Contact referral centre – give details of presentation and management
▪ Assist owner to arrange immediate transport
▪ Try to keep owner calm
Pre-surgical management of SI obstruction / incarceration / strangulation
▪ Broad spectrum antibiotic (usually penicillin & gentamicin)
– Gram positive and anaerobic cover with penicillin
– Gram negative cover with gentamicin
▪ Further anti-inflammatories?
▪ Tetanus prophylaxis?
▪ IV catheterisation
▪ IV fluid bolus isotonic (Hartmann’s) or hypertonic (7% NaCl)
▪ Correct acid-base and electrolyte abnormalities
▪ Naso-gastric intubation to empty stomach of reflux
– Keep it in for surgery so it can continue to drain
▪ Clip and scrub ventral abdomen
▪Don’t delay
Surgical management of SI obstruction / incarceration / strangulation
▪ Immediate ventral midline exploratory laparotomy under G.A
▪ Incision normally starts at the umbilicus and moves forward
– Incision length depends on what the suspected problem is
▪ Systematic examination of abdomen
→ for small intestine start at caecum, work through proximally through ileum, jejunum & duodenum
– Body of duodenum lies agains the ventral body wall
▪ Identify and correct lesion
▪ Viable bowel is left in situ
▪ Necrotic bowel is removed by resection & anastomosis
→ jejuno-jejunal or jejuno-ileal - end to end
→ jejuno-caecal – side to side
▪ Abdominal lavage
▪ 3 layer closure – linear alba, sub-cutis, skin
Post-surgical management of SI obstruction / incarceration / strangulation
▪ 5-7 days broad spectrum antibiotics – usually penicillin & gentimicin
▪ 5-7 days analgesia / anti-inflammatories as required – usually flunixin
▪ Regular clinical examination and adjustment of management
▪ Regular naso-gastric intubation to decompress stomach
→ post operative ileus is common following S.I. surgery
▪ IV fluids to correct dehydration, acid base imbalance and electrolyte deficits
▪ Gradual re-introduction of food and water after a few days
▪ Sometimes repeat laparotomy required
▪ Stable rest for approx. 8 weeks, then gradual turn out and return to exercise ▪ Lots of other things as well – every case is different
▪ Often put hay or feed outside the stable so they can smell it
– Hoping to induce gut motility
– Don’t know if this actually works
Clinical assessment of bowel viability - viable vs necrotic bowel
Viable bowel:
- Pink / red colour
- Colour improves as time passes
- Mild oedema
- Strong pulse in mesenteric arteries
- Serosa is shiny
- Motile
Necrotic bowel:
- Purple / green colour
- Colour does not improve
- Severe oedema
- Weak / absent pulse in mesenteric arteries
- Serosa is dull
- Non-motile
Surgical management of colon displacement/torsion
▪ Immediate ventral midline exploratory laparotomy under G.A
▪ Systematic examination of abdomen
→ for large intestine exteriorise caecum and entire colon (will require long incision)
▪ Identify and correct lesion, replace colon into correct location
→ gas removed with suction
→ ingesta may be emptied through pelvic flexure enterotomy
▪ Abdominal lavage
▪ 3 layer closure – linear alba, sub-cutis, skin
▪ Post surgical care similar to small intestinal disease, but ileus much less likely
Post surgical outcome
- ~70% go home from hospital
- ~50% long term survival
Pre-surgical factors predicting / affecting post surgical outcome
- Duration of signs prior to surgery
- Level of dehydration (TP & PCV)
- Level of endotoxaemia (MM colour, HR)
- SAA
- Lactate (circulating v peritoneal)
Intra-operative / post-surgical factors predicting / affecting post surgical outcome
- Specific lesion
- Length of bowel involved
- If resection & anastomosis required
- Expertise of veterinary staff
- Owner financial position
Post surgical complications (in increasing likelihood)
- laminitis
- repeat colic surgery
- d+
- reflux
- ileus
- incisional hernia
- jugular vein thrombosis
- wound infection
- colic
Enteritis vs colitis vs gastritis
enteritis = inflammation of the SI
colitis = inflammation of the LI
gastritis = inflammation of the stomach
Which horses/ponies are most likely to get strangulating lipomas?
- older horses
- fat ponies
What type/cause of colic can stallions get (that mares/geldings can’t)?
- scrotal hernias -> entrapment of the intestines
Why is recent foaling relevant to colic?
- recently foaled mares had a big gravid uterus that has now shrunken down -> lots of room that wasn’t there previously -> colon twist potentially could happen
Why can recent worming cause colic?
- if they had a high burden it can cause abdominal pain for a few days after worming
Why can horses lie down or on their back with colic?
- if reduces the weight/pull of the intestines on the mesentery
Are oral or IV fluids better for impaction?
- oral
