Equine Tx + Procedures Flashcards
Local anaesthesia
- Procaine (+ adrenaline)
- Lidocaine
- Lidocaine (+ adrenaline)
- Mepivicaine
- Bupivicaine
- Local infiltration
- Intra-abdominal infiltration
- Para-vertebral
Increasing duration of local anaesthetic
- Combine w/ vasoconstricting drug e.g. Epinephrine (adrenaline)-> slower systemic uptake
Use of morphine
- Epidural
- Intra-articular
- Horses only
Local anaesthetic injection sites in head - equine
- Mandibular foramen
- Mental foramen
- Infraorbital
- Mental
Epidural - horse
- Co1 - Co2
- Lidocaine 0.2 mg/kg + Xylazine 0.17 mg/kg
OR - Morphine 0.1 mg/kg diluted to 10 - 30 mL w/ saline
Open castration
- Standing sedation
- Parietal tunic is incised to expose testis, epididymis + cord structures before any haemostatic procedure
- Grab both testes + squeeze caudally so scrotal skin is tight + median raphe is visible
- Make bold (8 cm) scrotal skin incision(s), 2 cm either side + parallel to medial raphe
- Prolapse testis through incision + incise parietal tunic
- Release testis away from body + find ligament of tail of epididymis
- Cut/emasculate ligament of tail of epididymis (place emasculators 90 degrees to cord, nut to nut) - don’t suture up
- Apply emasculator nut to nut + leave for 2 min
- Repeat for other side
- Sx wound left to heal by second intention
Closed castration
- Surgical incision not made through parietal tunic
- Hospital conditions - sterile environment - dorsal recum
- On field - lateral recum, hind limbs restrained
- Make bold scrotal skin incision (not through parietal tunic)
- Exteriorise testicle as much as possible
- Use dry swab to strip fascia back
- Place transfixing ligature around whole cord - vicryl (not always put)
- Emasculate distal to ligature - closure of parietal tunic optional (suture)
- Close skin - intradermals
- Repeat for other testicle
- Can do in one or two initial incisions
Semi-closed castration
- Like closed, but parietal tunic is opened to allow inspection inside parietal tunic - better ligature placement = gold standard
- Make incision in scrotum + exteriorise/prolapse testis + place ligature of 5 metric vicryl (around parietal tunic - may need to make window between parietal + cremastor m.)
- Make 5 cm incision in parietal tunic to expose testis -> evert
- Sharp transection of ligament of the tail of the epididymis
- Optional - second ligature - double ligated w/ transfixing + circumferential - around vas deferens + blood vessels
- Emasculate distal to ligature - check for bleeding
- Close parietal tunic w/ monocryl or can leave to heal by 2nd intention on field when opened parietal tunic to inspect for herniation then emasculate everything from cremastor m.
Henderson castration
- Closed castration
- Low-speed cordless drill w/ sterile clamp attachment
- Place on testicle + twists at high speed until it tears
Castration local anaesthesia
- 10 - 20 mL along planned incision sites under skin (cranially + caudally)
- 5 - 10 mL into each testis (will diffuse up into spermatic cord)
Standing sedation
- Alpha-2 agonist + butorphanol
- Consider nose twitch
Donkey castration
- GA + closed or semi-closed
- Has larger than normal vessels, require ligation -> inc risk of infection + FB reaction
Sx patient prep
- Clean
- Tail tied/bandaged
- Long hair trimmed/clipped
- Povidone-iodine or Chlorhexidine scrub
- IV catheter if GA
- Mouth washed if GA
Pre-op therapeutics
- IV sedatives
- IV induction if GA
- IV NSAIDs
- Prophylactic AB?
- Tetanus antitoxin?
Pre-med sedation
- IV Alpha-2 agonist + butorphanol
Induction GA
- Alpha-2 pre-med
- Ketamine + Diazepam IV
IV pre-op NSAIDs
- Flunixin or Phenylbutazone
Pre-op prophylactic AB
- IM procaine penicillin or IV oxytetracycline
(Cheap, safe, licensed, first line, correct dose)
Prevention of tetanus pre-op
- Tetanus antitoxin + toxoid vacc
- Should vacc + do procedure later
Open castration post-op management
- Confinement in clean stable for 24 h to allow stabilisation of clots
- Excercise - start after 24 h, turn out in paddock
- Oral NSAID administration for 3 d
- O observe castration site (leave site, don’t manually clean)
- Maybe oral antimicrobials - TMPS
Closed/semi-closed post-op management
- Confinement in clean stable for several days
- Return to restricted exercise over next week
- Oral NSAID admin for at least 3 d
- O observe castration site (leave site, don’t manually clean)
- Maybe oral antimicrobials - TMPS
Cryptorchid Sx techniques
- Para-inguinal
- Inguinal
- Laparoscopic Sx = standing or GA, more expensive, gold standard when testes abdominal
H+ prevention in castration
- Keep hold of the spermatic cord until assessed H+ w/ Allis tissue forceps
- Larger/older horses + donkeys - do closed/semi-closed under GA + ligatures
Blood transfusion
- When PCV < 20% in acute bleeding episode
H+
- Don’t panic, give time
- Try clamping vessel w/ Mixter right angle forceps
- Packing w/ unrolled bandage
- GA + clamp/ligate a. - referral if possible
Seroma prevention - open castration
- Big surgical incisions
- Lots of movement post-Sx = important factor
- Ligatures not used, risk of H+ + swelling
- (Stretching incisions will improve drainage)
Seroma prevention - closed castration
- Reduce dead space
- Good Sx technique
- Rest + slow return to exercise post Sx
Seroma - open castration
- Re-open wound w/ sterile gloved finger
- Focus on re-establishing drainage
- Pos antimicrobials
Seroma - closed castration
- Don’t open wound if not believed to be infected
- Focus on reducing risk of 2y infection
- Pos antimicrobials
- Wound care
Scrotal infection - open castration
- Swab first -> C&S
- Clean wound w/ antiseptic
- Thoroughly open wound (gloved finger) + lavage
- Systemic AB - TMPS, Procaine Penicillin
- Systemic NSAID - Flunixin meglumine
Scrotal infection - closed castration
- Culture if pos
- Broad spectrum AB - TMPS
- Systemic NSAID - Flunixin meglumine
Emasculation of root of penis (iatrogenic penile trauma) from castration
- Emergency referral -> repair or phallectomy
Septic funiculitis (‘Scirrhous Cord’) (castration)
- C&S
- First line = antimicrobials (recurrent failure of appropriate antimicrobials = Dx)
- Bold Sx excision of thickened avascular + necrotic tissue
Peritonitis (castration)
- Referral for intensive care - IVFT, supportive care, injectable AB, anti-inflams, +/- peritoneal lavage)
Things protruding from incision site / evisceration of omentum (castration)
- High degree of sterility
- Pull out as far as possible
- Emasculate
- Monitor closely
Evisceration of SI (castration)
- Initial aim to protect bowel from further damage + further contamination + prepare for transportation
- Make protective sling + urgent transport to clinic w/ Sx facilities
- Pos - field anaesthetic, lavage, place back in scrotum + suture skin if possible
GA
- General anaesthetic
- Recum - horses don’t cope well in recum, particularly dorsal, dome of diaphragm, a lot of weight of gut contents on lungs - won’t perfuse blood as well, ventilation problem
- Full anaesthetic kit
- GA recovery facilities
- Accessibility/versatility
- Evidence base
Standing Sx
- Local anaesthetic - local infiltration of body wall + ligaments that hold structures; intra-abdo infiltration; paravertebral
- Standing in stocks = safer
- Specialist Sx kit
- Specialist approaches
- New
- No GA needed
- In a field - owner’s stables
- No anaesthetic equipment needed
- Ovariectomy/Cryptorchidectomy - better Sx access - hanging dorsally
- Quicker return to work/exercise
- Better ventilation
Laparoscopic cryptorchidectomy / orchiectomy
- Standing sedation + local block
- Secure haemostasis - by ligasure
- Excellent wound healing
- Rapid return to exercise - flank - within 2 - 4 w
(Ventral midline - out of work for long time) - Can aspirate fluid from ovary if enlarged to make smaller + remove from smaller lateral body wall incision
Old method of ovariectomy / non-laparoscopic
- Colpotomy - incision along ventral midline of cervix through vagina -> access to abdo - surgeon carries Ecraseur through - twists ovaries off ovarian ligament
- Ventral midline approach
- Flank approach
Ovariectomy aftercare
- 4 d AB + NSAIDs
- 1 w box rest + hand-walking
- 3 w paddock rest
- Gradual return to exercise
Prevention of recurrence of NSE (nephrosplenic entrapment)
- Laparoscopic closure of nephrosplenic space
- Place sutures between dorsal aspect of spleen and body wall
- Stops colon slipping into nephrosplenic space
- (V rare to have NSE colics)
Ventriculectomy
- By endoscope
- Excision of saccule - grasping forceps/transnasal burr
- Ablation of laryngeal saccule - scar tissue forms within saccule
- Laryngeal ventricles - blind-ended sacs of larynx
- Removal - dec noise
- Turn mucosa inside-out and remove - ventrally
- Clean-contaminated sx - leave incisions to heal by 2nd intention
Laser vocal cordectomy
- Laser used to excise vocal cord
- Grasping forceps
- H+
Dorsal displacement of soft palate
- Laser cautery of caudal part of soft palate
- Repeated application at 2 - 4 mm intervals
- Total = 1000J
Baseline post-op care of colic patient/abdo Sx
- Analgesia = Flunixin, 1.1 mg/kg/day IV divide into smaller doses
- CRI IVFT - isotonic, 40 - 60 mL/kg/24 h) - dehydrated, if endotoxaemic, losing fluid from vascular space
- Intestinal obstruction - still secreting fluid more proximal (SI) from obstruction but cannot be absorbed, fluid absorbed from distal intestinal tract (large colon)
- Monitor C/V status - HR inc, PCV inc, TP inc, membrane colour - check q 2 - 4 h
- Protect Sx site - belly bandage
- Manage - IV cannula
- Gut motility - don’t feed until normal
Restoration of gut motility post-op colic Sx
- Monitor signs of gut motility
- Movement, gentle walking
- Oral fluids + food - fluid by mouth after 12 h, offer small amounts of feed early (12 - 24 h post-op)
- (Average onset of ileus = 24 h) - inc intestinal secretions, if ileus -> dehydration
Gut motility signs
- US
- HR + PCV
- Gastric reflux (q 3 - 4 h)
- Auscultation
- Faeces - but still produce w/ ileus
Post-op colic (colic Sx)
- Relaparotomy
Incisional hernia avoidance
- Avoid wound infection
- Minimise movement/exercise strain - reduce strain on abdo wound
- Box rest 8 w
- Paddock rest 8 w
- Belly band
- Hernia belt
Post-op ileus
- Decompression - pass stomach tube to decompress stomach
- IV fluids
- Walk-out in-hand
- Prokinetic drugs - metoclopramide
- Lidocaine - anti-inflam/prokinetic?
Long-term colic Sx post-op management - once gut motility returned
- Remove cannulas as soon as redundant
- Re-introduction of oral fluids + feed
- Small vols of feed given regularly
- Monitor for signs of colic
- Monitor for CS BID
- Maintain belly bandage
- Frequent walks ‘in-hand; - can graze on lead-rope
Long-term colic Sx post-op management - following hospital discharge
- 8 w box rest
- 8 w paddock turnout before return to exercise
- Remove skin sutures/stables 10 d post-op
- Maintain belly bandage, first 2 - 3 w
- Low energy diet
- Monitor signs of colic
Long-term colic prevention
- Minimise amount of CHO fed
- Maintain regular feeding + management
- Monitor gut parasite status + Tx
- Maintain good dental care
- Early referral before endotoxaemia -> severe CVS parameters
- Early detection + Tx
- Anastomosis choice
- Dec stereotypies - wind-sucking/crib-biting
Osteochondritis dissecans/Chip fractures
Arthroscopy
- Removal of OCD fragments
- Debridement of cartilage lesions
- Lavage
Synovial sepsis
Arthroscopy
- Removal of bacterial debris
- Debridement of contaminated or traumatised tissue
- Lavage
Arthroscopy technique
- GA
- Dorsal recum
- Sterile prep
- Drape = imperviously (no gaps)
- +/- Distend joint prior to making skin portal for insertion of arthroscope
- Insufflate joint w/ sterile fluid
- Equipment
- Triangulation technique - bringing one or more operating instruments through separate portals into visual field of arthroscope w/ tips of instrument arthroscope forming apex of triangle
- Three holes, two for instruments, one for arthroscope
Fx
- Conservative
- Sx removal
- Sx repair - fixation
- Euthanasia
Fx fixation
- GA
- Strict Sx asepsis
- Pre-op planning
- AO/ASIF fixation systems
- Intra-op radio
- Bandage/cast for recovery
Arthrodesis
- Fusion of bones to a joint
- Best outcomes in low-motion joints, hind limbs have less weight, lighter horses
- Salvage procedure
- Pastern arthrodesis - low motion joint, return to modest athletic activity, better Px in hind > fore leg
- Tarsal arthrodesis - when medication not effective, chemical (kill chondrocytes, articular cartilage) or mechanical (drill across joint surface) arthrodesis, must be no communication w/ PIT (proximal intertarsal) joint - do contrast study
Impingement/overriding of dorsal spinous processes (kissing spines)
- Sx ostectomy
- Interspinous ligament desmotomy
Impingement/overriding of dorsal spinous processes (kissing spines) - Sx osectomy
- Bone removal
- Positioning - standing under sedation + local anaesthetic
- Spinous process resection - resection of summit of dorsal spinous process impinging
- Subtotal ostectomy - resection of portion of DSP (dorsal spinal process)
- 6 m recovery (more invasive)
- Px = good, 79% return to work
Impingement/overriding of dorsal spinous processes (kissing spines) - interspinous ligament desmotomy
- Ligament removal
- Positioning - standing under sedation + local anaesthetic
- Resection of interspinous ligament between adjacent impinging DSP
- 6 - 8 w recovery time (minimally invasive)
- Px = good, 82% return to work
Annular ligament constriction
- Annular ligament desmotomy
- Open or endoscopically-guided technique
- Px = excellent
DIP flexural deformity of the forelimb
- Inferior check ligament desmotomy
- Stretches muscle, allows DIP joint to come back to normal
- Open technique
- Px = good (w/ hoof trimming)
Periosteal transection - angular limb deformity
- ‘Release’ of periosteal tissue on the epiphysis to stimulate growth (growth plate)
- Transection of periosteum - allows bones to correct w/ bone growth - will compensate for flexion deformities
- Earlier, the better, foals
- Releases periosteal constriction - bone grows out after Sx
Tendon repair
- Various suture patterns
- Apposition of severed edges
- Support in cast for extended period post-op
- Px = poor, salvage (procedure only)
Post-op care of orthopaedic patients - Sx-specific
- Dressings/bandage to protect surgical site
- Monitor for swelling or discharge indicative of infection
- Post-op AB - may not be necessary
- Analgesia - phenylbutazone (NSAID)
- Removal of sutures/staples 7 d post-op
Post-op care of orthopaedic patients - husbandry
- Consider effect of movement on injury repair
- Controlled return to exercise
- Low-energy diet
- Risk of colic
- Weight-bearing?
- Analgesia?
- Foot support?
- Risk of contralateral laminitis
Orthopaedic cast management
- Inspection - integrity, heat (warmer over joints), discharge above?, seal top w/ bandage, early removal if signs of discharge or severe discomfort
- Duration - maintain for 2 w of comfortable/weight-bearing, remove standing, may need GA to replace half-limb cast
Surgical site infection - ventral abdo
- Wound cleaning + lavage - drain -> improve appetite
- Natural drainage - gravity
- Once open + draining
- AB use only if oedema + cellulitis (infection spread in tissues)
- Most infections in subcut
Synovial sepsis
- Rapid < 24 h surgical lavage
- Intensive AB Tx
- If left late -> euth
Restricting movement of lesion during wound healing
- Stable
- Even less, maintain standing - cross tying - head collar, lead ropes attached to wall, stopping sitting down, when gets up, puts strain on Fx site
- Bandage
- Robert jones bandage - inc layers
- External support - if suspect Fx, add splint to bandage
- Cast material
Types of wound dressings
- Dry, semi-occlusive e.g. Melolin - sterile, limited absorption capacity - only absorb bit of blood/serum from Sx wound/minimally contaminated, clean traumatic wound
- Poultices - anything wet to apply hoof wall -> softens hoof wall, keeping moisture in, allowing drainage of e.g. solar abscess
Wound management - dealing w/ infection, minimising bacterial load
- Lavage - high-pressure fluid
- Drainage (passive/active) - incision stays open + pus material drained out
- Sx debridement
Wound suturing
- First intention healing mixed in w/ second intention - be selective about cases
Colic - relief of intestinal obstruction
- Enterotomy
- Evacuation of obstruction
- Lavage
- Closure of enterotomy
Colic - large colon evacuation
- DV pos
- Tapwater for external lavage - don’t want to contaminate serosa of intestine, flushing it away
- Pelvic flexure enterotomy
- Ingesta into bucket
Colic - small intestinal enterotomy
- Use inverting suture pattern
Small colon - Faecolith
- Enterotomy
Colon displacement correction
- Decompress gas w/ needle
- Evacuate ingesta - enterotomy incision
- Manipulate + reposition colon
Nephrosplenic entrapment
- Starvation + patientence
- Gentle exercise e.g. trotting
- Phenylephrine (40 mg in 1 L saline) + lunge, vasoconstriction causes spleen to contract to dislodge colon from nephrosplenic space -> intestines move out
- GA + roll - rarely needed
- GA + laparotomy - only if persistent - any evidence of ischaemia
Enterotomy closure
Inverting suture patterns: to minimise adhesion formation
- Lembert
- Cushing
Intestinal strangulation - intestinal resection
- Ligate mesenteric vessels
- Cut mesentery - remove ischaemic gut -> secure ligation
- Section aborally (away from mouth)
- Decompress via ischaemic gut
- Section orally
- Anastomosis - of healthy bowl
- Aim to restore continuity of gut
- If > 50% of SI resected, will need diet modification
- > 60% - consider euth
- Most important component of post-op care = IVFT for restoration of CVS func
End-to-end anastomosis
- Equal diameter ends
- Two layer technique - mucosal continuous suture, inverting oversew (cushing)
- 3M absorbable material
- Close mesentery
- Lower complication rate
Side-to-side (stapled) anastomosis
- Jejuno-caecal anastomosis
- Minimises risk of contamination
- Time saving
- Reinforce ends w/ sutures
- Can perform hand-sewn equivalent
Sampling for histology
- Small piece of full thickness intestine
- Single layer closure
- Pot = formalin/Bouin’s
No wound contraction below carpus/tarsus
- Skin graft - to provide epithelial tissue to keep granulation tissue in check
Proud flesh (exuberant granulation tissue)
- Granulation tissue not sensitive, doesn’t contain nerves
- V vascular, drapes unerneath
- Resect/cut
Anaesthetic nasal oedema prevention
- Use lateral recum (if pos)
- Intra-nasal phenylephrine - vasoconstriction to eliminate oedema
- ET or nasopharyngeal tube for recovery
- Should correct quickly when horse stands up, but horse has to recovery, only remove ET tube when standing + swallowing - replace epiglottis returns to soft palate
- If bad acute airway obstruction + attempts to place tubs then tracheostomy
Anaesthetic neuropathy + myopathy prevention
- Reduce pressure on all points - remove head collar; padding; lateral: dependent forelimb pulled forward, upper limbs supported; dorsal: don’t allow stifles to lock -> inc muscle perfusion
- Ensure Major veins unobstructed
- Avoid tension of nerves – don’t overextend neck or limbs - support neck - if hyperextend can stretch recurrent laryngeal n. + cause laryngeal paralysis
- Need to allow surgical access
Anaesthetic hyopxaemia prevention
- Prevention of V / Q mismatching - low inspired gas conc (30 - 50%) - prevent absorption atelectasis
- Inc FiO2 if PaO2 is below 100 mmHg
- Positive-end-expiratory pressure (PEEP) of 5 - 10 cm H2O w/ Intermittent positive pressure ventilation (IPPV)
- Pre-med w/ ACP to reduce pul shunt
- [Beta-agonists - clenbuterol injection - too many side effects; salbutamol (albuterol) by inhalation]
Anaesthetic hypotension
- Dobutamine
- IVFT - as infusion
- Controlled mechanical ventilation
Sedatives/antagonists (not licensed but 6 m withdrawal times for FPAs)
- ACP
- Atipamezole - romifidine antagonist
Muscle relaxants (not licensed but 6 m withdrawal times for FPAs)
- GGE (Glyceryl Guaicolate Ether)
- Diazepam
- Midazolam
GA (not licensed but 6 m withdrawal times for FPAs)
- Propofol
- Sevoflurane
Opioids (not licensed but 6 m withdrawal times for FPAs)
- Buprenorphine
- Morphine (not licensed)
- Pethidine
- Butorphanol
Inotropes/vasopressors (not licensed but 6 m withdrawal times for FPAs)
- Dobutamine
- Dopamine
- Ephrdrine
Local anaesthetics (not licensed but 6 m withdrawal times for FPAs)
- Bupivacaine
- Prilocaine (EMLA cream)
Anaesthesia patient prep
- IV catheter
- Rinse mouth
- If using padded induction box - remove shoes or cover
Pre-medication for anaesthesia (neuroleptanalgesia)
(Sedation - ACP)
- Alpha-2 agonist (in order of inc duration) - xylazine, detomidine, romifidine
- Opioid - butorphanol, buprenorphine, pethidine, morphine
Induction of anaesthesia
- Ketamine + central muscle relaxant (midazolam (licensed)/diazepam IV or GGE (guaifenesin) IV to effect
- Encourage head to dog-sit
Maintenance anaesthesia (TIVA)
- Ketamine induction dose gives ~ 10 minutes of surgical anaesthesia
- Short procedures: maintain
with intermittent bolus doses of ketamine - Long procedures: variable rate infusion (e.g.‘Triple Drip’)
Intermittent IV bolus
- Ketamine (1/3 induction dose q 8 min, 2 min onset)
OR - Thiopental 1 - 2 mg/kg when patient moves not licensed, accum may affect recovery
- Xylazine 1/2 pre-med dose w/ every top up
- Detomidine 1/2 pre-med dose every other top up
Variable rate infusion (triple drip)
- Guaifenesin 10% in 500 mL, Ketamine 100 mg/mL 10 mL + detomidine 10 mg/mL 1 mL or xylazine 100 mg/mL 5 mL / 20 mg/mL 25 mL
- 1 mL/kg/hr, 2 - 3 drops/s
- Adv - more stable plant of anaesthesia
- Disadv - relative cost, 90 min max
Anaesthesia monitoring
Field
- Physiological parameters - pulse – facial artery; respiratory rate (HR may not change when light)
- Eye pos - unreliable w/ ketamine (doesn’t depress cranial reflex)
Hospital
- Eye Position - central with sluggish palpebral reflex for surgical anaesthesia; too light: eye rotates, palpebral brisk; too deep: eye central, no palpebral
- Pulse Oximeter, Blood pressure, capnography, blood gas analysis, etc
Anaesthesia recovery
- Minimise noise/light stimulation - towel over upper eye, pack ears with cotton wool
- Keep quiet - observe from a distance if in recovery box
- Usually stay with horse if recovering in field
- Keep in lateral as long as possible - head collar + lead rope
- Additional sedation - w/ inhalational if pre-med worn off, unlikely to need in field, shouldn’t need w/ Romifidine - wears off
- Catheterise bladder
Post-anaesthesia analgesia
- Phenylbutazone IV at time of Sx
- PO for 5 d
Standing sedation therapeutics
- Acepromazine 0.03 mg/kg - dec dose, less ataxic
- Alpha-2 agonist
- Opioid
- IV in same syringe (can sometimes exclude ACP)
Extending standing sedation duration
- 1). Top-up IV bolus of alpha-2 agonist
- 2). Alpha-2 agonist infusion
Sedation in foals (< 2 w/o)
- Cardiac output directly related to heart rate; hypotension occurs quickly
- Avoid alpha-2 agonists due to cardiovascular effects
- Benzodiazepines and opioid combination readily cause recumbency -> short procedures e.g. imaging
- Sedation: Diazepam/MIDAZOLAM (0.2 mg/kg) + morphine (01. - 0.1 mg/kg)/butorphanol (0.2 mg/kg)
Multimodal anaesthesia
- NSAID - Phenylbutazone, Suzibutazone, Flunixin, Firocoxib, Meloxicam, Carprofen etc
- Opioid - Butorphanol, Buprenorphine, Pethidine or Morphine
- Local - Lidocaine, Mepivacaine or Bupivacaine
- Adjunct - MLK (Morphine, Lidocaine and Ketamine) Infusions α-2 agonists, paracetamol, gabapentin
Jugular vein catheterisation
- Teflon (angiocath) - short stay, max use 3 d, advanced imaging
- Polyurethane (Mila) + silicone - longer stay, 3 - 4 w if maintained properly, less rigid, e.g. fluids post-colic Sx
Catheter maintenance
- Adequately secured
- Regularly inspected for kinking, bung/extension secure, skin around catheter kept clean
- Flushed with heparinised saline at least 4 times daily
- Injection port wiped with spirit or removed prior to injection
- ALWAYS check for patency prior to injection
- Do not leave in longer than necessary or recommended
Catheter complications - placement
- Haematoma - puncture of jugular v gone through other side - reposition/apply pressure to area to stop blood flow if hit carotid
- Catheter tip extravascular
- Catheter embolism
Catheter complications - in-dwelling
- Occlusion of catheter - ensure patency, kinking
- Thrombus
- Thrombophlebitis
- Septic thrombophlebitis
- Air embolism
Common problems encountered in hospitalised horse
- GI problems
- Unexplained fever
- Hyperlipaemia
- Jugular vein thrombophlebitis
- Unwillingness to drink + inappetence
GI hospital issues
- Hospital environment unnatural for horse - used to being turned out + fresh grass
- Inc susceptibility to - colic, D+ + gastric ulceration
Colic - hopitalised
- Stall confinement linked to large colon impactions, 53.7% of horses had increased stall confinement prior to developing large colon impaction
- Caecal impactions - can develop very quickly, reduced faecal output and mild depression
- Most at risk: Thoroughbred in training (reduction in exercise), hospitalised for orthopaedic injury, confined to a stall and on NSAID
- NSAIDs/analgesia - can mask early signs of colic, need to monitor!
D+ hospitalised
- Isolate (barrier nursing -> isolation) - pyrexic, systemic signs, suspicious of infection, profuse watery diarrhoea +/- foul smell
- Identify cause (not always possible!) - Hx, blood, faecal samples - Salmonella (PCR or culture-repeat samples advised, required neg result for 5 d to leave isolatioin) C. difficile toxin analysis, abdominal US
- Treat symptomatically - restore + maintain circulating blood volume → Intra venous fluid therapy
- Control systemic inflammation - analgesia/anti-inflam +/- anti-endotoxic therapy
- Antimicrobial therapy
- Nutritional support - encourage to eat correct diet
Thrombophlebitis
- Immediately remove IV catheter
- Collect catheter tip and send for culture & sensitivity
- Avoid catheterising other JV due to risk of bilateral JV thrombosis
- Hot pack site several times daily
- Systemic antimicrobial therapy if infection suspected
- NSAID
In addition - Topical anti-inflammatories e.g DMSO, Compagel
- Anti-thrombotic: aspirin administered every other day
Thrombophlebitis - prevention
- Minimise vein trauma in critical horses
- Sterility during placement
- Use minimally thrombogenic catheters
- Long catheters less complications that short catheters
- Consider how at risk a patient is – hypercoagulable state?
- Flush with heparinised saline q 4 - 6 hrs at least
- Keep catheter site clean and dry
- Check patency before catheter flushed and drugs administered
- Monitor for heat, swelling or discharge at catheter site
Unwillingness to eat (hospitalised)
- Treat underlying cause
- Offer a variety of feeds
- Fresh grass – appetite stimulant
If no clinical reason to explain unwillingness to drink - If horse receiving IVFT then likely sufficiently hydrated
Fussy horses - Bring in water bucket/water from home
- Flavour the water - apple juice, electrolyte mix
- Oral salt (30 - 60 g NaCl) to stimulate intake
- Soak hay and feed to increase fluid intake
- Place small bore indwelling nasogastric feeding tube for ongoing fluid delivery
Hyperlipaemia
- Resolution of underlying disease process
- Establish positive energy balance
- Reduce stress to limit anxiety and encourage appetite
- Most patients inappetent - enteral or parenteral nutrition often required
- Horse: glucose/dextrose infusion 1-2 mg/kg/min of 50% solution
- Ponies/miniature horses/donkeys - may also require tube feeding or parenteral nutrition containing amino acids
- Daily monitoring of triglyceride levels in blood until they have returned to normal limits
- Px guarded unless diagnosed and treated early