Local Analgesia and Anesthesia Flashcards
What are the types of local anesthetic agents?
Ester-type local anesthetic agents
Amide-type local anesthetic agents
What are the ester-type local anesthetic agents?
Procaine
Tetracaine
What is the onset of action for procaine?
Rapid
What is the duration of procaine?
Short
What is procaine used for?
Infiltration
Regional blocks
What is the onset of action for tetracaine?
Slow
What is the duration of tetracaine?
Long
What is tetracaine used for?
Topical anesthesia
What increases the potency of a drug?
Increased lipophilic
What are examples of amide-type local anesthetic agents?
Lidocaine
Mepivacaine
Bupivacaine
What is the onset of action for lidocaine?
Rapid
What is the duration of lidocaine?
Intermediate
What is lidocaine used for?
Local blocks
Regional blocks
Antiarrhythmic (IV)
What is the onset of action of mepivacaine?
Rapid
What is the duration of mepivacaine?
Intermediate (> than lidocaine)
What is mepivacaine used for?
Local blocks
Regional blocks
Intrarticular (horses-diagnostic)
What is the onset of action of bupivacaine?
Intermediate
What is the duration of bupivacaine?
Long
What is bupivacaine used for?
Regional blocks
Epidural anesthesia/analgesia
Intraarticular analgesia (small animals)
What are complications and toxicity of local anesthetic agents?
Local anesthetic overdose IV administration Cardiovascular and CNS toxicity CNS excitation, depression, inconsciousness Centrally mediated muscle contraction/seizures Respiratory center depression = apnea Peripheral vasodilation = hypotension Decreased CO Bradycardia Ventricular fibrillation Cardiac arrest Allergic reaction Methemoglobinemia Tissue damage Infection
What is toxicity dependent on?
Potency
What is topical anesthesia?
On theucous membranes
What is used in topical anesthesia?
Tetracaine or lidocaine 2%
Avoid Benzocaine
Total dose <5 mg/kg
What is used for infiltration anesthesia?
Lidocaine, Mepivacaine, or Procaine
Epinephrine
What does epinephrine cause in infiltration anesthesia?
Prolongs block
Ischemia
Cardiac arrhythmias
What is used in regional anesthesia of the head?
Bupivacaine 0.5%; lidocaine 2% (0.1-0.2 ml per site)
Combine with sedation or general anesthesia
What is used for a brachial plexus block?
Bupivacaine 0.5% or Ropivacaine 0.5% +/- dexmedetomidine 0.5 μg/ml
What should a brachial plexus block be avoided in?
Conscious animals
What is used in sciatic and femoral nerve block?
Bupivacaine 0.5% or Ropivacaine 0.5% +/- dexmedetomidine 0.5 μg/ml
What should a sciatic and femoral nerve block be avoided in?
Conscious animals
What is used in IV anesthesia (Bier Block)?
Lidocaine 1% or 2%
What happens if an IV block is used for >90 minutes?
Ischemia, pain, sepsis
What is IV anesthesia used for?
Sutures or biopies, and digit amputation
What is used for an intraarticular block?
Bupivacaine (or Ropivacaine) 0.5%
Usually combine with opioids
What is used in a ring block?
Infiltration technique with lidocaine or bupivacaine
What is used in lumbosacral epidural anesthesia?
0.5% bupivacaine (0.1-0.2 ml/kg) +/- preservative free morphine 0.1 mg/kg
What does lumbosacral epidural anesthesia do?
Regional block of the spinal nerves
What is used in intrapleural and intercostal blocks?
Bupivacaine 0.5%
What do intrapleural and intercostal blocks do?
Pain management of thoracic injury or surgery
What is used in the auriculopalpebral nerve block in horses?
Lidocaine 2% or Mepivacaine 2%
What is auriculopalpebral nerve block used for in horses?
Motor block of the eyelids
eye examination
Corneal foreign body removal
What is used for a supraorbital nerve block in horses?
Lidocaine 2% or Mepivacaine 2%
What does a supraorbital nerve block do in horses?
Blocks motor and sensory innervation of the upper eyelid
Eye exam
What is used for an infraorbital nerve block in horses?
Lidocaine 2% of mepivacaine 2%
What does an infraorbital nerve block do in horses?
Sensory block of nostrils, roof of nasal cavity, maxillary sinus, upper lip, skin up to the medial canthus of the eye, upper teeth to the first molar
Adjunct to general anesthesia for trephination of maxillary sinus and upper teeth extraction
What is used for a mental nerve block in horses?
Lidocaine 2% or Mepivacaine 2%
What is a mental nerve block used for in horses?
Sensory block of the lower lip
Rostrally to the mental foramen
What is used for a mandibular alveolar nerve block in horses?
Lidocaine 2% or Mepivacaine 2%
What is a mandibular alveolar nerve block used for in horses?
Mandibular alveolar nerve into the mandibular canal
Supplement to general anesthesia for lower incisors or premolar extraction
What is used for a retrobulbar ocular block in horses?
Lidocaine 2%
What is a retrobulbar nerve block used for in horses?
Adjunct to general anesthesia during eye surgery to prevent oculocardiac reflex
What is used for epidural anesthesia in horses?
Lidocaine 2% +/- xyalzine
Where is epidural anesthesia done in horses?
First coccygeal interspace
What are indications for epidural anesthesia in horses?
Surgery of the tail, perineum, rectum, vulva, vagina, inguinal region
Obstetrical procedures
Relieve tenesmus
What is used for proximal paravertebral thoracolumbar anesthesia in horses?
Lidocaine 2%
What is paravertebral thoracolumbar anesthesia used for in horses?
Standing exploratory lapratomy
Desensitizes spinal nerves T18, L1, and L2
What is used for a cornual nerve block in ruminants and swine?
Lidocaine 2%
What is a cornual nerve block in ruminants and swine used for?
Dehorning cattle and goats
Cattle: cornual nerve block and infiltration of the caudal aspect of the horn
Goats: Nerve block of cornual branches of zygomatocetemporal and infratrochlear nerve
What is used for a retrobulbar block in ruminants and swine?
Lidocaine 2%
What is a retrobulbar block used for in ruminants and swine?
Neuromuscular desensitization of the eye and eyelid
Enucleation, eye, or eyelid surgery
What is the peterson block used for in ruminants and swine?
Sensory and motor block of the eye
What is the ring block used for in ruminants and swine?
Infiltration around the limb
What is the indication for IV regional anesthesia in ruminants and swine?
Digit surgery
What is blocked with IV regional anesthesia in ruminants and swine?
Venous and arterial blood flow
What should be selected to use for IV regional anesthesia in ruminants and swine?
A superficial vein as distal as possible
What does proximal paravertebral thoracolumbar anesthesia do in ruminants and swine?
Desensitizes the spinal nerves T13, L1, and L2
What indicates a successful paravertebral thoracolumbar anesthesia technique?
Increased skin temperature and hemilateral scoliosis
What is the indication for line block anesthesia in ruminants and swine?
Flank laparotomy
What is the volume of anesthethic related to in line block anesthesia?
Incision length
Where is a caudal epidural done in cattle?
Sacrococcygeal of first interoccygeal space
What should be used in caudal epidurals in small ruminants and why?
Lidocaine 2% 1-2 ml to avoid prolonged paralysis