Surgery 2 Flashcards
Hoof bandage
Can be wet or dry
After surgical procedures-softening
Extends under fetlock
3-5 days
Distal limb bandage
Surgical sites or intraarticular injections
From coronary band to carpus or tarsus
Fixed to hoof capsule by impermeable tape
Robert-Jones bandage
Immobilization of the limb and joints!
Standard bandage with additional sheet cotton
1.5x the circumference of the limb
Split can be applied to strengthen
Carpal bandaging
From coronary/fetlock to above the carpus
Hole/pressure releasing pads over acc carpal bones to prevent pressure sores or pressure necrosis of skin
Normal bandage plus strengthening additional layers
Splints can be applied for more restriction of movements
Carpal splint
When need stabilization of the limb- luxation, fracture, tendon rupture
On top of Robert-Jones
Proper protection of acc!!!
Split from coronary band/fetlock to under the elbow
Tarsal bandaging
Same as carpal but this time pressure releasing pads over the common calcaneal tendon
Common problems of bandages
Slipping/rotation of bandage and splint Too tight or too loose Pressure necrosis of skin Uneven tension of bandage Contamination
What is neuroleptanalgesia
sedatives and analgesic
for standing position procedures and diagnosis
head comes down to carpal level- head support may be needed
Partial unconsciousness and muscle relax– can add analgesia for surgical procedures
Combos for neuroleptanalgesia
ACP and Butorphanol
Xylazine and Butorphanol
Detomidin and Butorphanol
ACP and Xylazine and Butorphanol
Cardiopulmonary effects of alpha2 agonists
- Vagal tone incr– bradycard– decr CO
- Hypertension at beginning.. then hypotension
- if give IV– temp grade I and II AV block
- Dysrhythmia or arrhythmia
- Central resp depression
GI effects of alpha2 agonists
Block the swallow reflex
Reduced visceral motility and perfusion to the organs
Hyperglycaemia
Are good visceral analgesics– therefore good for colic
Cardiopulmonary effect of opioids
Resp depression
Hypotension
Bradycardia
Opioid drugs used: agonists
Methadone: 3-4x more potent than morphine
Morphine
Morphinum hydrochlorium
Fentanyl- lipophilic so use a patch
Opioid drugs used: agonists-antagonist
Butorphanol
Pentazocin
Opioid drugs used: antagonist
Naloxon
Nalorphin
Local anaestheisa: physical methods
Ties and tourniquets: nerve press and anaemia
Cool: at 4degrees- stops the potency of nerve stim
Local anaesthesia: chemical
Esters: cocaine, procaine and tetracaine.. are hydrolysed by plasma pseudo-cholinesterase
Amides: lidocaine, mepivacaine and bupivacaine- are metab by the liver and so are better
Cannot be absorbed through intact skin
Local anaesthetic used in optho
Oxibuprocaine and proparacaine
These are 10-15x more effective than procaine
Can be toxic for the corneal epithelium
Local anaesthetics for mucus membranes and skin
Lidocaine: most stable, good penetration: 1.5-2hrs
Bupivacaine: 4-6 hrs
Mepivacaine: fast effect! only lasts 1-2hrs
Methods of local anesthesia
Topical Infiltration Regional IV Intrasynovial Perineural Paravertebral Epidural
Local anaesthesia: Infiltration
Safest
2% lidocaine
SE: hematoma
Local anaesthesia: Regional IV
IV catheter and Esmarch tourniquet
2% lidocaine (same as for infiltration)
Local anaesthesia: Intrasynovial
Intraarticular
Intrathecal bursa
Tendon sheath: Mepivacaine, bupivacaine, lidocaine
Local anaesthesia: Perineural uses and types
Lameness diagnosing
Palliative- laminitis hoof cast
Surgery of the head
Periorbital
Dental and muzzle
Corneal
Local anaesthesia: Paravertebral anaesthesia
Laparoscopy and flank laparotomy
If successful block– vasodilation, sweating– Horner’s syndrome like
Local anaesthesia: Epidural
Sedation Btw Cc1 and Cc2 Drugs used: 2%lidocaine Xylazine (and saline) Detomidne and morphine Morphine
ASA classification of risk categories for surgery
- Healthy horse
- Mild systemic disease– mild anemia, RAO
- Severe systemic disease– severe RAO
- Severe systemic that is life-threatening– colic, polytrauma
- Moribound horse, not expected to survive for more than 24hrs– foal with uroperitoneum
E. Emergency
Preoperative evaluation
Goal: to define the risk for the owner
To select the best strategy to minimize the risks
- Free airway- intubation
- O2 supply
- IPPV= intermittent Postive Pressure Ventilation
- Venous Pressure Catheter
- CPR= cardio pulmonary resuscitation
Patient prep for surgery
- History- prev anaesthesia
- Physical exam- focus on resp, CV, musculoskeletal and CNS
- For emergency cases- first treat shock and stabilize
- Lab tests: elective selection: PCV, TPP sometimes hematology
- Fasting– no water for 6 hrs prev–lung function, decr chance of stomach rupture and decr risk of postop ileus
- Body weight- drug dosages
Surgical Complications and emergencies
Cardiopulmonary resuscitation Anaphylaxis Intraoperative hypotension During maintenance Hypoxemia and Hypoxia Hypercapnia Postop myopathy Postop neuropathy Postop laryngeal edema
Cardiopulmonary resusitation
Intraop mortality 30% due to cardiac arrest
Caused by deep hypotension and the anesthesia
Signs: EtCO2 decreases Weak pulse Cyanotic mm Dilated pupils Kussmaul type breathing
Tx: discontinue anesthetic admin IPPV Chest compression 60x/min O2 supply IV drugs
Anaphylaxis
Causes:
vasoD and incr vessel permeability
AB’s- penicillin and aminoglycosides
Just after drug admin there is: spO2 decr, weak pulse, bronchospasm, pulmonary edema
Tx: Stop giving the drug IPPV O2 Give epinephrine, AH's etc
Intraoperative hypotension: what it is and causes:
Happens with inhalational more so than TIVA or PIVA
Make sure ABP is over 70mmHg, foals should be lower
Myocardial depression- endotoxaemia
Bradycard
Hypovolemia, acidosis and electrolyte imbalance–shock
Intraoperative hypotension: consequences
Poor tissue perfusion Postop myopathy SC ischaemia Cerebreal necrosis Myocardial dysfunction
Intraoperative hypotension: treatment
Infusion– electrolyte, colloid, hypertonic
(+)inotrop– dobutamin
calcium
During maintenance
hypovent– V/Q mismatch– hypoxemia
decr CO
Hypoxemia and hypoxia: what it is and causes
Hypoxemia: paCO2 is less than 60mmHg
Hypoxia: inadequate tissue oxygenation
Causes: Failure in O2 supply Hypoventilation Problems with endotracheal tube Distended abdomen putting pressure on thorax RAO Acute pulmonary edema Shunt
Hypoxemia and hypoxia: Methods of improving
Early vent–IPPV
Increase FiO2
Albuterol bronchoD
Pulsed delivered NO
Hypercapnia: What it is, causes, effects and treatment
When paCO2 is greater than 45mmHg
Causes:
Resp centre depression
Hypovent
Incr CO2 prod
Effects:
Symp stim
Arrhythmia, resp acidosis
Intracranial P incr
Tx:
IPPV– get to anesthesia depth
Postop myopathy: causes and treatment
Causes: Large body Long anesthesia time Inadequate padding Intraop hypotension and hypoxemia
Tx: Adequate padding Assistance in standing Mild cases- exercise and walking Mannitol infusion Vit E and selenium Massage
Postop neuropathy
Caused by inadequate padding and conditioning, overextension of limbs
Radial, femoral and facial nerve injury
Treatment similar to myopathy
