Primary assessment of colic Flashcards
What is colic?
- colic describes the clinical signs of abdominal pain
Broad causes of colic
▪Many different diseases can cause colic
▪Most are caused by gastrointestinal disease, but can also be caused by pathology of other abdominal structures (liver, spleen, urogenital system)
Intestinal causes of colic
- Impaction/obstruction
- Strangulation (loss of blood supply)
- Ulcers
- Enteritis
- Displacement
- Herniated intestine
- Intussusception (rare unless young animal)
- Ileus (common after surgery)
- Spasmodic colic (moves too much)
- Gas/tympanic colic (excess gas)
Clinical signs associated with severe/critical cases
▪ Severe unrelenting pain (including signs of self trauma)
▪ Dullness and depression (can indicate septicaemia, rupture)
▪ Abdominal distension
▪ Heart rate >60bpm
▪ Discoloured mucous membranes or delayed capillary refill time
– Horses mm are smoked salmon, more yellowy cf other spp
▪ Absence of gut sounds in one or more quadrants
▪ Relate to obstruction or strangulation +/- cardiovascular compromise
Approach to colic - horse: signalment, behaviour, attitude
- Age
- Gender/reproductive status
- History of crib biting or wind sucking
- Recent changes in weight/condition
- Attitude to pain (stoic or expressive)
Approach to colic - management/yard environment
- Recent changes in:
i. Stabling/pasture turn-out
ii. Forage feed
iii. Exercise regime
iv. Hard feed
v. Access to water - Previous episodes of colic on the yard
- Whether horse has access to sand
Approach to colic - Owner factors
Is surgical tx/referral an option?
Approach to colic - Preventative healthcare
- Whether any parasite control/treatment is used
- Whether strategic parasite control (e.g., faecal egg counts and strategic worming) is used
- Date horse last received anthelmintic (de- wormer)
Approach to colic - Previous medical history
- Previous history of colic
i. If yes, frequency and nature of colic episodes - Previous abdominal surgery
- Current medication
- Other medical issues
- Recent history of sedation or anaesthesia
Approach to colic - Current episode
- When horse last seen behaving normally
- When horse last passed faeces; appearance of faeces
- Signs horse has been exhibiting and whether they have changed over time
- If colic has occurred previously, comparison with previous episodes
- Management since vet contacted
- Administration of any
treatment/analgesics
Basic assessment
(must be performed in all cases)
* Heartrate
* Mucous membranes
o Capillary refill time
o Colour
o Moistness
* Gut sounds
* Rectal temperature
Assessment of pain
- Pawing
- Attempting to lie down
- Flank-watching
- Box-walking/circling
- Sweating
- Rolling
- Kicking
- Demeanour
- Facial expression
- Pain scoring - Colorado pain socre
How to approach a severe/critical case
Basics of history
▪ Age, duration of signs, previous history, recent changes
Basics of physical examination
▪ Pain assessment
▪ Heart and respiratory rate
▪ Mucous membrane colour and CRT
▪ Gut sounds
Analgesia or sedation to control situation and allow more thorough examination
Shared decision making with owner
How are critical cases of colic defined?
Those in which the horse requires:
* Euthanasia on humane grounds
OR
* Hospitalisation for intensive medical or surgical treatment
Signs of a critical case of colic - pain
- Pain despite analgesia
- Abrasions
– Result from rolling/thrashing/being cast
– Typically found above the eyes and on other bony prominences - Thrashing
- Unresponsive
- Rolling continuously/throwing
themselves to the ground - Continuous box walking
- Sudden alleviation of signs
– This usually indicates gastric or intestinal rupture
Signs of a critical case of colic - the CV system
- Tachycardia (>60 bpm)
- Abnormal mucous membranes
– Colour: Red, purple, blue, grey
– Moistness: Dry
– ‘Toxic ring’ (red or purple line above teeth) - Capillary refill time >2.5 seconds
- Weak pulse character
- Elevated packed cell volume
Signs of a critical case of colic - the GIT
- Significant (>4 L in a 500 kg horse) or spontaneous NG reflux, and/or foul mouth odour
- Identification per rectum of:
– Distended Sl loops
– Severe LI distension
– LI displacement - Peritoneal fluid discoloured or turbid
- Abnormal abdominal ultrasound
- Severe abdominal distension on
visual observation - No gut sounds in ≥1 quadrant
- Peritoneal lactate >2 mmol/L
Signs of a critical case of colic - case progression
- Rapid deterioration of signs
Diagnostic tests
- Response to analgesia
- Rectal examination
- Nasogastric intubation
Safe approach for diagnostic tests
▪Identify a suitable area for examination and procedures in a
colicing horse
▪Make sure the owner/handler is working safely and understands what you will be doing
▪Make sure you are in a safe position and protected where possible
▪Consider use of sedation (alpha-2 agonists) and GI relaxants (hyoscine)
▪See resources on safety and restraint, and analgesia and sedation
Reasons for performing a rectal exam
- Key diagnostic test for horses with suspected colic
- May allow you to rule various diagnoses in or out
Indications for performing a rectal exam
Any horse with:
o Clinical signs of colic
o Recent history of colic
Particularly indicated if the horse:
* Demonstrates severe pain
* Has a high heart rate (>60 bpm)
* Has other critical signs, and requires a decision around referral for surgical or intensive medical treatment
Contraindications for performing a rectal exam
- Risk to vet, handler, or horse which cannot be managed by restraint/sedation
- Unacceptable risk of rectal tear
Other factors to consider before performing a rectal exam
- Lubrication must always be used prior to insertion of your arm into the rectum
- The owner should be informed immediately about any complications or rectal tears
- Assess potential risks to the horse, yourself, and the handler
- Rectal examination allows palpation of the caudal third of the abdomen only
– Clinically significant lesions may not be palpable - Tell the owner what you’re planning to do and explain the rationale for the procedure
Reasons for performing nasogastric intubation
- For horses with colic, nasogastric intubation is both diagnostic and therapeutic
Diagnostic value
o Allows you to determine whether the stomach contains excessive fluid
o >4L of nasogastric reflux from a 500kg horse indicates that the case is probably critical
Therapeutic value
o Failure to remove excessive fluid from the stomach may lead to gastric rupture, with fatal consequences
o If there is no excessive fluid, and parenteral medication or fluid is indicated, these can be administered via the tube
Indications for performing nasogastric intubation
- Spontaneous nasogastric reflux
– Perform nasogastric intubation first in these cases - Distended small intestine (requires rectal or US for diagnosis)
- Suspected critical case of
colic - Severe pain
- Requirement for enteral fluids
- High heart rate (>60 bpm)
- Primary impaction†
- High respiratory rate (>20 brpm) associated with abdominal pain or distension
Other factors to consider before performing nasogastric intubation
- It is important to create a siphon in the tube; without this, fluid that is present may not flow
- You may have to manipulate the tube within the stomach to start the flow of reflux
- Epistaxis is a common complication; the volume of blood can be considerable
- Owners may find nasogastric intubation
distressing, especially if it causes epistaxis
– Explain the procedure and potential complications before starting
Potential complications
Injury to vet or handler
▪ Assess situation
▪ Consider yours and handlers safety first
▪ Sedate when needed
▪ Ask for help / refer when needed
▪ Euthanasia is realistic option if horse is uncontrollable and dangerous
Rectal examination ▪Rectal tear
Nasogastric intubation
▪ Epistaxis
▪Inadvertent administration of treatment into lungs
Why do rectal tears occur?
▪ Most occur as a result of a contraction around the hand or forearm
▪ Less commonly as a result of finger tip penetration
▪ Can occur as a result of external trauma, impaction, or
spontaneously
Grading rectal tears
▪ Grade I – mucosa and submucosa torn
▪ Grade II – muscular layer only torn
▪ Grade IIIa and b – all layers torn except serosa or mesorectum
▪ Grade IV – all layers torn
Grade I & II - some barrier between bacteria and blood stream
1st aid for rectal tears
- Identify it, acknowledge it and inform owner
- Perform essential first aid to reduce straining and contamination
- Phone for help (senior partner and VDS)
First actions:
▪ Sedate horse, administer spasmolytic (if not done already)
▪ Repalpate carefully with ungloved hand to identify extent of injury
▪ Gently remove faeces from tear and rectum
▪ Treat septic shock and peritonitis (NSAIDs and broad
spectrum antibiotics)
▪ If able to, administer epidural and pack rectum
▪ Refer
Outcome of rectal tears
▪Grade I and II – most will heal with medical treatment (antibiotics, laxatives and dietary changes)
▪Grade III – require careful monitoring and most will require surgery
▪Grade IV – many euthanased, some can be managed surgically
▪Surgical options are direct suturing if possible, plus temporary indwelling rectal liner and colostomy
Nasogastric intubation complications 1st aid/tx
- Epistaxis
▪ Common and messy, prewarn owner before procedure, normally self limiting – bleed from pharynx or turbinates, so packing nostrils does not reach site of origin - Incorrect tube placement
▪ Check that tube is in oesophagus – watch left side of neck during placement, check for tracheal ‘rattle’, suck back on tube (oesophagus closes round tube end, trachea does not), listen and smell contents to check in stomach, administer small amount of water first
▪ Presence or absence of coughing does not confirm correct tube placement
▪ Do not use liquid paraffin – no evidence of benefits, higher risk of complications (lipid pneumonia which they can’t shift)
▪ Risk of pneumonia – treat with NSAIDs and broad spectrum
antibiotics (flunixin, pencillin and gentamicin)
Why should you not be misled by a quiet horse?
- Could be septic or have ruptured
What is the most important risk factor? Why?
- If anything has changed with their management recently
- Important for prevention in the future
Prognosis for a case that does not respond to analgesia
- poorer
- critical case
What is a common sign of a rupture?
- Thrashing around then suddenly quiet (when you haven’t done or given anything)
Why is NG tubing so important?
- If the SI is blocked or their is no gastric outflow it will rupture
- NG removes the fluid/gas/pressure
Example of unacceptable risk of a rectal tear
- a small pony (12h minimum?)
- a foal
- repeatedly straining
What to do if straining before rectal exam?
- give more drugs
How far in should you be able to feel during a rectal exam?
- Up to the right kidney (in small ponies)
- Up to the caecum
Indications of a SI blockage
- High HR
- Distended SI on rectal
- Looking painful and sick
Why stomach tube after rectalling?
- If there’s an impaction you’ll use the stomach tube to give fluids
- Need rectal to know whether there’s an impaction
