Equine Emergencies: Recognition & Basic Steps Flashcards
what is the definition of emergency
a serious unexpected and often dangerous situation requiring immediate action
what are the body systems that can include emergencies
- alimentary and liver
- respiratory
- cardiovascular, spleen, blood
- nervous system
- special senses
- urinary system
- musculoskeletal
- integumentary
- reproductive
what are emergencies in the alimentary and liver
colic (1 in 10), abdominal trauma (eventration)
what are urgent incidents in the alimentary and liver (4)
- choke (esophageal obstruction)
- colic (potentially)
- poisons/toxins
- concentrate overload
what are respiratory emergencies (2)
- dyspnea (obstruction)
- thoracic trauma (open thorax)
what are cardiovascular, spleen and blood emergencies (3)
- severe hemorrhage
- wound
- guttoral pouch mycosis
what are nervous system emergencies
- trauma/fracture of cranium or spinal
what are urgencies in the nervous system (3)
- tetanus
- pharyngeal paralysis
- vestibular syndromes
what are special senses emergencies
- corneal laceration
what are special senses urgencies
- closed eye
- uveitis
- corneal ulceration
- eyelid laceration
what are urinary system urgencies (2)
- obstruction to urine outflow
- trauma to penis
what are musculoskeletal emergencies (4)
- fractures
- some tendon and ligament injuries
- wounds (laceration or puncture)
- atypical myopathy
what are musculoskeletal urgencies (5)
- wounds (laceration or penetration)
- synovial contamination
- foot penetration
- myopathy
- laminitis
what are integumentary urgencies (2)
- wounds
- burns
what are reproductive emergencies (2)
- dystocia
- red bag delivery
what are reproductive urgencies (2)
- retained placenta
- foal not sucking
how can you prepare for an emergency
- support: have all the phone numbers (colleagues/team, info/contacts)
- facilities: in house, referral options, transport contacts, disposal options
what equipment should be prepared for an emergency (4)
- restraint
- drugs: sedation, anesthesia, analgesia
- equipment: stomach tubes, funnel, rectal gloves, lube, clippers, flash light, scrub, bandages, suture, surgical kit, splints, IV fluids, catheters, sterile gloves, farrier and dental equipment
- euthanasia: somulose
how do you triage and prioritize emergencies
on the phone
- history & signalment
- guidance while they wait
what guidance could you give an owner while they wait for a vet
- remove all food from a choke/colic
- don’t remove if nail in foot
- bleeding wound apply pressure and don’t remove
- red bag delivery –> talk through won’t make it in time
what questions should you ask to triage at the scene (4)
- is this really an emergency?
- are there humans at risk?
- clinical exam - patent airway? vital parameters TPR, hemorrhage?
- prioritize one animal over another?
what are the ABCD
A: establish an airway
B: breathing for patient
C: circulation (chest compressions, right lateral recumbency –> knees in adults and hands in foals)
D: drugs
what can cause upper airway obstruction (3)
- severe trauma/swelling/edema of head/nasal passages
- pharyngeal obstruction (severe strangles, Streptococcus equi)
- severe laryngeal obstruciton: laryngeal swelling/edema, bilateral laryngeal paralysis (traumatic, hepatic encephalopathy, primary neurological, idiopathic)
how do you treat upper resp obstruction
bypass the upper resp tract –> emergency tracheostomy
how is an emergency tracheostomy performed (4)
- usually upper third trachea: 3rd-5th tracheal ring
- midline verticle incision: divide muscles (sternothyrohyoideus) overlying trachea
- stab incision through annular ligament between two rings: extend either side big enough to allow placement of tracheostomy tube
- secure to neck
what is the circulating blood volume of a horse
7-8% of body weight
500kg = 35-40 litres
what volume of blood can horses lose before they decompensate
~30%
what are the clinical signs of hemorrhage
- increased resp rate
- pale mucous membranes
- high heart rate
- poor perfusion
what are external causes of hemorrhage
- wound
- guttural pouch mycosis
what are internal causes of hemorrhage
abdominal/thoracic: broad ligament hematoma in mares post-parturition
what are the clinical signs of significant blood loss (3)
- tachycardia
- tachypnea & hyperpnea indicative of significant hypovolemia and hypoexmia
- mucous membrane colour depends on severity of loss (pale/white)
what should be included in your clinical exam (6)
- is the animal viable?
- respiratory, CV, musculoskeletal (evidence of poor peripheral perfusion, dehydration, sepsis, endotoxemia), organ systems
- shock, exhaustion, trauma
- injuries that are immediately life threatening (open body cavity)
- what injuries will be exacerbated by moving/rescue/extraction (stabilization)
- history
what are the reasons for sedation
- human safety
- animal safety
when would chemical sedation be used
any procedure: assess risks - how can they be mitigated? (environment or handler? other restraint? PPE?)
before you sedate what should you do first
- clinical exam: focus on CV system due to side effects
- quite environment: avoid excitement, minimize stimulation
- choice of sedation and dose and route
what factors determine what sedation should be used
- age, breed and temperament
- clinical findings
- procedure to be performed (duration, expected pain level)
- previous sedation history
what is the duty of care when administering sedation
to horse, owner, farrier even for sedate to clip
horse is still dangerous
how are alpha-2 adrenoreceptor agonists as sedatives
reliable, dose-dependent
what are alpha-2 adrenoreceptor agonists usually combined with and why
opioid to decrease the likelihood of being kicked but doesn’t eliminate it
ex. butorphanol
do alpha-2 agonists provide analgesia
yes
visceral (for colic) and somatic
do alpha-2 adrenoreceptor agonists cause muscle relaxation
yes
may assist in treatment of choke
what else are alpha-2 adrenoreceptor agonists used for
anesthesia as pre-medication
what are licensed alpha-2 agonists in the UK
how long does xylazine IV last
20-30 mins
how long is the onset of action of xylazine IM
15-20 min
what are the disadvantages of xylazine
not as reliable, shorter duration and more expensive
what is xylazine useful for
assessment of fractious colic on its own
permits exam and allows reassessment of pain at end of this time, allows full assessment before use longer acting analgesia
obtain heart rate before administer
what is the duration of detomidine
45-60 mins IV
what routes can detomidine be used
IV
IM (30 min onset)
oral transmucosal gel
when is detomidine used
routine work
what is detomidine combined with typically
butorphanol
how does detomidine compare with romifidine (4)
- romifidine with butorphanol “plants” feet to ground better
- greater muscle relaxation: greater instability and ataxia
- greater sedation at lower dose range
- greater analgesia
can detomidine be used with colic
use with care, usually on its own
potent analgesic (10x xylazine) with longer duration
reserve for horses with severe, unrelenting pain (can mask escalating pain)
what is the duration of romifidine
60-120 mins IV
when is romifidine used
routine work in combo with butorphanol
can romifidine be used for colic
yes but not particularly useful
what is the route of choice for alpha-2 agonists
IV
what is the onset of action following IV of alpha-2 agonists
2-5 mins
allow time to take effect
what is the “ceiling effect”
further increasing dose increases duration but has no effect on intensity
improve intensity using a combo with opioid
what are minor side effects/disadvantages of alpha-2 agonists (5)
- hyperglycemia
- diuresis
- sweating
- decreases in PCV and total protein
- no food until awake - esophageal choke
why do alpha 2 agonists cause diuresis
not clear why
low renal threshold for glucose and produces glucosuria
alpha 2 receptors on renal tubules antagonize ADH
how do alpha 2 agonists cause sweating
vasodilation, increased blood supply to skin
what are important side effects of alpha 2 agonists (5)
- bradycardia
- arrhythmogenicity
- reduce GI motility (and secretions)
- upper airway obstructions
- care in pyrexic horses –> can induce tachypnea
how do alpha 2 agonists cause bradycardia
reduce cardiac output and respiratory depressants (care in foals)
interpretation of colics –> heart rate
how do alpha 2 agonists reduce GI motility (and secretions)
impair assessment of colic
repeated doses or CRI –> can cause colic (large colon impactions)
how can alpha 2 agonists cause upper airway obstructions
muscle relaxation can exacerbate pre-existing obstructions
impairs endoscopic assessment of upper respiratory tract
why do you need to take care in pyrexic horses when giving alpha 2 agonists
can induce tachypnea and can be antipyretic
what can be used to reverse a2 agonists
a2 antagonist –> atipamezole
what opiods can be used for sedation
butorphanol is licensed for use in horses
when does butorphanol cause sedation
in combo with alpha2 agonist
what kind of analgesia does butorphanol provide
relatively poor, has claim for visceral analgesia
what are the side effects of butorphanol (2)
- reduces SI activity but minimal effect on pelvic flexure
- CV and resp depression
what are the sedation protocols
alpha 2 agonist (sedation & analgesia) + opioids (augments sedation & analgesia)
ex. detomidine and butorphanol
romifidine and butorphanol
common to mix in same syringe
what is the dose of sedation dependent on
size, age, temperament, procedure and excitement
heavy breeds more easily sedated than a fractious arab
keep stimulation to a minimum
what is an example dosage for heavy sedation of standing castration
- 9ml/100kg romifidine and 0.2ml/100kg butorphanol
- 1ml/100kg detomidine and 0.25ml/100kg butorphanol
what is an example dosage for mild to moderate sedation of a calm pony for a dental exam
total volume: 0.2ml detomidine and 0.3ml butorphanol
total volume: 1ml romifidine and 0.5ml butorphanol
what is a top up dose of sedatives
typically 1/4 to1/3 of initial dose
when would CRI of sedatives be used and how would you do this
- prolonged procedure
place catheter and add loading dose (detomidine and butorphanol)
ex. add detomidine to 500ml bag 0.9% NaCl and start set rate for 5-10 mins then slow and titrate to effect
how would you sedate a difficult horse
IM alpha 2 agonist or remote injection using length of tubing
dart gun?
what routes of ACP are used
IV
IM
oral gel
what are the effects of ACP
anti-anxiety (sedation but no analgesia)
what is the duration of ACP
4-6 hours
when is ACB used on its own
to calm an anxious, but cooperative horse (clipping)
not good enough for invasive procedures/difficult horses
what else is ACP used for
- premedication for anesthesia
- difficult horse prior to sedation with alpha 2 agonist and butorphanol
- sometimes used in combo with a2 agonist and butorphanol to aid exam of a gelding penis
when is ACP contraindicated
breeding stallions –> priapism and paraphimosis (rare)
what is the approach in assessing wounds
anatomy: bone, soft tissues, synovial
how do you plan treatment of musculoskeletal injuries
- functional and cosmetic
- management at home
- management at your clinic
- cost
when would musculoskeletal injuries be referred
extensive
synovial structure
fracture
what are steps to do before musculoskeletal injury referral (6)
- plan a good referral: once assessed wound talk to referral hospital, first aid and preapre horse for transport
- bandage plus/minus splint: stabilization is key
- immobilization is essential: for fractures, many wounds, foot injuries, radial paralysis
- prophylactic antimicrobials
- analgesia
- tetanus
what are uses for antimicrobials
- existing infection
- prophylactic use or pending the above
how do you select which antimicrobial to use (7)
- does it need it?
- what bacteria are likely to be involved?
- select drug that will reach effective concentrations at site of interest
- pharmacodynamics: mode of action against bacteria - are bacteria of interest susceptible?
- pharmacokinetics: dose, route, frequency - maintain effective concentration at site of interest for duration
- effective in local environment?
- adverse reactions/toxicities? licensed?
what are the main options of analgesia used in the horse (7)
- NSAIDs
- alpha 2 adrenoreceptor agonists
- opioids
- paracetamol
- lidocaine infusions
- ketamine including infusion
- gabapentin
what are the classical signs of colic
- pawing
- flank watching
- rolling
- distressed
- increased resp rate
- sweating
- odd stance
- dull demeanour
- not eating
what is central to colic management
analgesia
where are most colics located
GI tract
what types of colic will have an impact on CV and resp systems
strangulating obstruction of SI that causes ischemia
what are other types of colic (8)
- urogenital,
- liver
- spleen
- ovulation
- uterine torsion
- dystocia
- broad ligament hematoma
- calculi (renal, urethral, cystci, urethral)
what other things can look like colic (8)
- laminitis
- peritonitis
- myopathy
- esophageal disease including primary choke
- neurological
- pneumonia/pleuropneumonia
- cardiovascular
- pyrexia of unknown origin
what are further diagnostic tests of colic (7)
- rectal exam
- nasogastric intubation
- response to analgesia
- blood analysis
- abdominocentesis
- ultrasonography
- exploratory laparotomy
what are the classifications of colic
- spasmodic
- impactive
- flatulent/tympanic
- obstructive
- non-strangulating infarction
- enteritis
- idiopathic
what are the types of obstructions
- mechanical
- paralytic ileus
what are the two types of mechanical obstruction and name some examples of them
- simple obstruction: intraluminal; mural; extraluminal
- strangulating obstruction: internal and external hernias, pedunculated lipomas, intussusception, volvulus, fibrous bands and adhesions, arterial thrombosis
what are primary and secondary paralytic ileus
primary: gass sickness
secondary: post-operative, anterior enteritis, peritonitis
what is a simple large intestinal obstruction (6)
- congenital abnormalities
- impaction
- intraluminal concentrations
- foreign bodies
- displacement of large colon
- strictures
what are examples of large intestinal strangulating obstruction (4)
- volvulus
- intussusception
- pedunculated lipoma (small colon)
- vascular disease
where is the NG tube placed
via ventral meatus
warn the owner it can cause nosebleed
what are the diagnostics of NG tube
>2 litres reflux –> SI obstruction
OR
tube can’t be placed –> choke
how is an NG therapeutic and for treatment
- short term for SI obstruction to prevent gastric rupture
- analgesia - dilated stomach is painful
- admin of fluid or medication
what analgesics can be administered for colic
- NSAIDs: phenylbutazone, funixin meglumine, ketoprofen, meloxicam
- alpha-2 agonists: xylazine, detomidine (care 10x potency), romifidine (least analgesia)
- opioids: butorphanol (relatively poor analgesia, duration ~1.5 hours) or pethidine (rarely used), morphine, buprenorphine (duration ~8-12 hours)
- antispasmodics: anticholinergic not true analgesia –> buscopan or buscopan compositum (butylscopolamine and metamizole)
how do NSAIDs provide analgesia
inhibit COX enzymes preventing prostaglandin synthesis –> peripheral effect, COX 1 and COX 2
what are possible adverse effects of NSAIDs
- nephrotoxicity
- right dorsal colitis - more significant morbidity in the horse
- gastric ulceration
what analgesia does phenylbutazone provide
moderate analgesia
what is the duration of bute
short action ~ 2 hours
what is bute not licensed for
colic or visceral pain
what analgeisa does meloxicam provide
moderate similar to phenylbutazone
what COX selectivity does meloxicam have
COX 2 > COX 1 (selective)
what is ketoprofen licensed for
alleviation of visceral pain
what is the most potent NSAID
flunixin meglumine
how long does fluniximin meglumine last
long duration of 6-8 hours
what other effect does flunixin meglumine have
ant-endotoxic effect
why do you need to take care when administering flunixin meglumine
potent analgesic so could mask deterioration in colic
when should you use flunixin meglumine
definitive diagnosis
prior to referral
what considerations should you make when you are coming up with treatment and management plan
- don’t need a diagnosis
- can you do it?
- do you need additional resources?
- best treatment option?
- referral?
- is the client on board?
what are the owner factors when referring a patient (6)
- clear communication
- offer options
- finance: insurance
- referral an option?
- what was/is this horse expected to do
- emotional attachment
what considerations need to be made when referring (4)
- ask for advice from referrel centre
- transport to centre?
- support for horse: bandage, immobilization, analgesia, refulx - travel with NG tube, foals need their mares
- support for owner: directions, contact numbers
how should you communicate euthanasia
“take” owner with you
what methods are there for euthanasia
- somulose
- pentobarbitone (Euthatal)
- free bullet
what is the criteria for humane desctruction
responsibility is on the vet based on their assessment of the clinical signs at time of exam, regardless of whether or not the horse is insured
the vet’s primary responsibility is to ensure the welfare of the horse
what are some examples for criteria for immediate destruction (7)
- catastrophic injury
- open fractures
- gross and unstable comminuted fracture
- proximal long bone fracture
- axial skeleton/cranium fracture
- sustained recumbency (>24 hours)
- owner request
what should you discuss with the owner before euthanasia
- empathy
- insurance
- what will happen during and just after
- disposal and possible post-mortem, mane, tail, shoes
what should you consider about location during euthanasia (3)
- privacy and noise
- surface and hazards
- extraction for disposal
what can go wrong during euthanasia
- spare bottle of somulose etc
- catheter could come out
- bystanders?
what is somulose
quinalbarbitone and cinchocaine combo
what does somulose cause
CNS depression and cardiac conduction depression
how is somulose administered
IV jugular cathete, secured
what gives optimal results with somulose
alpha 2 sedation prior to euthanasia
what is the dose of somulose
1ml/10kg over 10-15 seconds
what is somulose classified as
schedule 2 controlled drug
kept in register, locked container
what are the safety considerations with somulose
absorbed through skin or mucosa –> avoid self injection
what are the steps to euthanize using somulose
- inject over 10-15 seconds
- take horse off owner/handler and they step away behind you
- firm downward pressure on head (apply pressure on shoulder and guide horse down)
- horse recumbent: ensure everyone stays out of kicking zone
what should occur within 5 mins of somulose administration
agonal breathing, other reflexes, no heartbeat, lack of corneal reflex, pupils dilated and fixed
how are horses injected with somulose disposed of
fallen stock
cremation
burial on own land but there are some resitrictions
