Presented by

Dr. Awad Rizk(Mvsc, Ph.D-Tiho-Hannover,Germany)

03.11.2011

Contents IntroductionDefinition of local analgesiaMechanism of actionAdvantages and disadvantages of LAGeneral considerationsDesirable characters of local anestheticsPharmacokinetic of local anestheticsLocal anesthetics adjuvants and combinationsLocal anesthetic toxicityCommon local anesthetic agentsMethods of local analgesia application

The subjects (classification) of anesthesia

1.Local anesthesia (analgesia)

2.Regional anesthesia (analgesia)

3.Tranquilization &sedation

4.Narcosis

5.General anesthesia

OverviewLocal anesthetics produce desensitization and analgesia of the

skin surface (topical anesthesia), tissues( infiltration and field

block) and regional structures( conduction anesthesia,

intravenous regional anesthesia)

Local anesthetic techniques are an alternative or addition to

intravenous and inhalation anesthesia.

A number of anesthetic drugs are available , they vary in

potency, toxicity and cost

The most commonly used Local anesthetic drugs are lidocaine,

mepivacaine and bupivacaine Hcl

Vasoconstrictors (epinephrine) are occasionally incorporated

with or added to lidocaine to increase the intensity of effect and

prolong anesthetic activity

Adding the hyaluronidase increases tissue penetration in the

region of infiltration and hasten the analgesic activity.

Local analgesia: is a loss of sensation in a limited body area through a selective transient paralytic action on the sensory terminal nerve and nerve endings.

Preemptive local analgesia in animals

undergoing general anesthesia :

will reduce the amount of general anesthetic

minimizing the cardiopulmonary depression

leading to quicker recovery.

It provides a useful pain relief, even beyond the

full recovery from general anesthesia.

Definition

Mechanism of action of LA

It acts by interference with transmission of impulses by

preventing the increase in membrane permeability of the

nerve cell to sodium ions.

LAs block nerve conduction by inhibiting influx of sodium ions

through ion-selective sodium channels in nerve membrane

leading to impairment of the generation of action potential.

The sodium channel itself is a specific receptor for local

anesthetic molecules.

Mechanism of membrane and impulse conduction

All clinically used LAA are membrane stabilizing agent

They enter and occupy the membrane channels through which

ions normally moves.

The most immediate and apparent effect is to prevent the

outflow of sodium ions and therefore block all subsequent ionc

flow.

They prevent depolarization and therefore stop or retard

conduction of impulses

+ +

- -

+ +

--

- -

+ + + +

- -

Na+

+ ++ +

- - - -

Resting (Closed**)

Open

(brief)

inactivated

Very slow repolarization in presence of LA

LA receptor

LA have highest

affinity for the inactivated

formRefractory period

**Closed state may exist in various forms as it moves from resting to open. LA have a high affinity for the different closed forms and may prevent them from opening.

Local analgesiaLocal analgesiaAdvantages

1-It is suitable for performing surgery on standing animals,

accordingly injuries associating casting and prolonged

recumbency can be avoided

2-The technique is simple and requires no expensive or

complicated equipment

3-The technique can be performed by the surgeon himself with

no need for anesthetist

Disadvantages

1-Injection shouldn't be performed in infected area to avoid

spreading of infection

2-Direct injection of the drug at seat of incision causes delay of

healing as a result of histotoxic effect of the drug

3-The amount of used local analgesic drug is relatively higher

than other methods like perineural analgesia, accordingly the

cost increases

Use sterile solutions, equipment's, and techniques

Avoid injection into inflamed area (if possible)

Use as small a gauge needle as practical

Aspirate for blood before injecting

Use lowest effective conc. Of LA drug to produce the

desired effect.

Wait for onset of analgesia before proceeding

General considerations

Desirable characters of local AAGood penetrating quality of tissue

High potency (low conc can be used)

Rapid onset

Long duration of action

Low systemic toxicity

No irritation to nerve or other tissue

Reversible action (reversible block of nerve conduction)

Ease to be sterilized

NONE totally meets these optimally yet!!

Local anestheticsLocal anesthetics can be divided chemically into two groups:

Esters: procaine, cocaine, and tetracaine

Amides: lidocaine, mepivacaine, and bupivacaine

Esters: Inactivated quickly by non-specific esterases in the

plasma and tissue

Amides: More stable, longer plasma half-lifes

Factors affecting activity and potency

Lipid solubility

Increased drug lipid solubility tends to slow the rate of onset of

action, increase the duration of action, and increase potency.

Protein binding

Increased plasma protein binding tends to be associated with

increased duration of action.

Pharmacokinetics of local anesthetics

A. Absorption

Systemic absorption of a local anesthetic is dependent on a

number of factors:

1. Dose

• The greater the dose injected, the greater the systemic

absorption and peak blood concentration

2. Injection site

• Administration into a highly vascular area (e.g. mucosal,

pleural or peritoneal surfaces) results in rapid absorption and

higher blood concentrations compared with injection into less

perfused areas (e.g. subcutaneous tissue, perineural fat).3. Drug–tissue binding• The more potent local anesthetics with greater lipid solubility and protein binding are associated with lower systemic absorption .4. Vasoconstrictors• Decrease rate of systemic absorption .

B. Distribution

LA can be widely distributed to all parts of the body including CNS

Distribution is a means of terminating local drug action ........ not

metabolism!!

Due to their rapid metabolism and short plasma half-lives,

distribution of ester-type agents is limited.

Conversely, amide local anesthetics are widely distributed after

intravenous administration.

C. Metabolism and excretion

• Biotransformation of local anesthetics depends on the chemical

structure of the drug.

Aminoester metabolism

• These agents are rapidly hydrolyzed in the blood (and to a lesser

extent in the liver) by non-specific pseudocholinesterases.

• The rate of hydrolysis varies (chloroprocaine > procaine >

tetracaine), but clearance is generally rapid and half-lives are

measured in minutes.

• Para-aminobenzoic acid (PABA) is a breakdown product of ester

metabolism.

Aminoamide metabolism

• These agents are hydrolyzed by the liver cytochrome enzyme

system.

• The rate of hepatic metabolism varies (lidocaine > mepivacaine >

bupivacaine), but clearance is slower than that of the esters, and

half-lives are measured in hours.

– Reduced hepatic biotransformation and clearance of amide local

anesthetics may prolong duration of action and increase the risk of

toxicity.

Local anesthetic adjuvants and combinations

A. Vasoconstrictor (Epinephrine)

5 μg/ml (1:200,000) may be added to a local anesthetic solution

to decrease local perfusion, delay absorption, and prolong

anesthetic action.

When administered into the epidural or subarachnoid spaces,

epinephrine may enhance analgesia through interaction with α-

adrenergic receptors in the spinal cord and brain.

Effects of vasoconstriction Delay absorption

Reducing toxicity

Increase the margin of safety

Increase intensity

Prolong anesthetic activity (up to 5 times)

It may cause disturbance in circulation( teats, distal limbs, penis)

Can increase risk of cardiac arrhythmia and ventricular fibrillation

B. Alpha2 agonists

Effects on peripheral nerve blocks

Studies suggest that the addition of an α2 agonist may

potentiate peripheral nerve blocks with local anesthetics in

human patients.

Effects on epidural anesthesiaAdding xylazine to lidocaine potentiates and prolongs

anesthesia when administered into the caudal epidural space

in horses.

This synergism is due to activation of α2 adrenergic receptors

in the spinal cord dorsal horn.

This combination is used commonly in clinical equine practice

for caudal epidural anesthesia.

C. Hyaluronidase

This enzyme may be added to a local anesthetic solution to break

down hyaluronic acid which functions as mesenchymal tissue cement.

increases tissue penetration in the region of infiltration and hasten

the onset of analgesic activity

D. Carbon dioxide

• Carbonation of LA solutions causes local intracellular acidosis which,,

increases the amount of intracellular ionized drug available to bind

Na+ channel receptors and accelerates the onset of action.

• This practice does not appear to significantly improve block quality in

equine patients.

F. Combinations of local anesthetics

• The combination of a quick-onset, short-acting, local anesthetic with a

slow-onset, long-acting, local anesthetic has theoretical benefit.

Local anesthetic toxicity

When used correctly, local anesthetics have proven to be

safe, and adverse effects are not common.

Toxicities can be divided into three categories:

systemic

local tissue toxicity

allergic

A. Systemic toxicity

• This is most often the result of inadvertent and

rapid intravenous infusions producing a dose-

dependent continuum of effects on the brain and

heart.

Central nervous system

In horses, procaine is an exception to this rule, demonstrating a

low anesthetic potency but a high propensity to cause CNS

stimulation .

Low doses of local anesthetics tend to produce CNS depression,

while higher doses cause CNS excitation.

Significant CNS excitation is evident after IV boluses of

approximately 2.5 mg/kg of procaine in horses (50 ml for 400 kg)

and is characterized by deep, rapid and forced inhalations, fine

muscle tremors and pawing at the ground.

• Skeletal muscle tremors are usually the first signs of toxicity in

horses, and progress to seizures, unconsciousness, coma, and

respiratory arrest.

– Muscle tremors are evident at serum lidocaine concentrations of

approximately 3 μg/ml in horses, or with IV boluses of

approximately 4–6 mg/kg (80 ml for 400 kg).

– Seizures are induced with IV boluses of approximately 6–8

mg/kg.

Skeletal muscle cont.…

Adult horses safely tolerate up to 250 ml of 2% lidocaine ( 11

mg/kg) for infiltration of the paralumbar fossa for abdominal

surgery.

Benzodiazepines, barbiturates, inhalational anesthetics, and

potentially propofol are effective in treating local anesthetic

induced seizures and oxygen supplementation are indicated in

cases of toxicity.

(Cardiovascular system (CVS• Significantly higher serum concentrations of local anesthetic are

required to produce CVS toxicity compared with CNS toxicity.

• Characteristics of CVS toxicity :

All may decrease myocardial contractility.

The less potent agents (lidocaine, mepivacaine) cause bradycardia

and hypotension.

The more potent agents (bupivacaine, ropivacaine) cause

malignant ventricular dysrhythmias that are resistant to

treatment.

B. Local tissue toxicity

When applied in excessively high concentrations, all local

anesthetics have the potential to be toxic to nerve tissue,

especially when administered via the spinal route.

Reports of adverse neurologic sequelae after subarachnoid

administration

C. Allergic reactions

• Allergic reactions to aminoamide local anesthetics are extremely rare.

• Aminoester local anesthetics are metabolized to para-aminobenzoic

acid (PABA) derivatives which may induce Type I hypersensitivity

reactions in a small percentage of patients.

Limiting the total quantity of drugs

Use of dilute solution

Retarding absorption

Administration of CNS depressant

Repeated aspiration before injection

of local AA How to avoid toxicity

1.Cocaine the original local anesthetic (Isolated in 1860 from Coca leaves(

is the only one to cause vasoconstriction.

It is now not used as a local anesthetic because of its potential

for abuse (Schedule II).

Local anesthetic agents commonly used in vet. practice

2.Procaine hydrochloride(novocaine)

Procaine (novocaine) largely replaced cocaine (First synthetic local

anesthetic), and has in turn been displaced by lignocaine.

It presents as white powder and it used as freshly prepared watery

solution.

It causes local vasodilation and poorly absorbed from the surface of

the MM or skin so it is not used for topical analgesia.

Combined with adrenaline hydrochloride, procaine absorption

is slow, solutions may be sterilized by boiling and there is

minimal tissue irritation.

• Has an intermediate onset (10–15 min) and short duration

(45–60 min).

• A 2% solution has been used for local infiltration, peripheral

nerve blocks, and intra-articular anesthesia.

3.Lidocaine (xylocaine or Lignocaine)

Lidocaine has largely replaced procaine as it has the advantage of:

• extreme stability

• more rapid diffusion

• longer duration of action

• useful surface analgesic activity on mucous membranes and cornea as

it has the ability to penetrate the MM

• The most commonly used local anesthetic in clinical equine practice.

• Rapid onset (5–10 min) and intermediate duration (60–90 min).

• Available as:

– An aqueous solution in various concentrations (0.5–5%) with or

without epinephrine.

– A gel in concentrations of 2–5%.

– A 10% lignocaine spray.

– A transdermal preparation.

•Effective doses for peripheral nerve blocks and caudal epidural

anesthesia in horses typically do not exceed 0.2–0.3 mg/kg (i.e.

approximately 5–8 ml of the 2% solution in an average adult horse).

it is used as topical anesthesia in the form of jell or oint.

Commonly used for induction of local infiltration and epidural

analgesia.

Most common conc. 1- 2%

Doesn’t cause vasodilation

Studies in human patients indicate that

systemic lidocaine has a beneficial effect on

bowel motility, and this makes it an

attractive analgesic adjuvant for the equine

colic patient

4.Bupivacaine hydrochloride (Marcaine)

• Is a potent local anesthetic.

• Variable onset (10–30 min, depending on the route of administration).

• Long duration (180–480 min) of action.

• It is available as an aqueous solution in various concentrations (0.25–

0.75%).

• The 0.5% (5 mg|ml) formulation is most commonly used .

•Doses for peripheral nerve blocks and caudal epidural anesthesia are

in the range 0.05–0.08 mg/kg (i.e. 5–8 ml of the 0.5% solution in an

average adult horse).

Not effective topically.

• Due to its extended duration of action, caution is advised when

administering it into the caudal epidural space, as overdose could result

in very prolonged periods of hindlimb weakness and motor deficits.

• More cardiotoxic than lidocaine and IV administration is

contraindicated.

• Available as a single optical isomer (levo-bupivacaine).

– Levo-bupivacaine appears to be associated with 30–40% less systemic

toxicity .

5.Cinchocaine (Nupercaine™, Dibucaine®)

is more toxic than procaine, but concentrations for epidural block and surface analgesia are lower (0.5%).

Other properties include:

longer analgesia than with procaine

drug readily decomposed by action of alkalis and therefore syringes

and needles should, if not sterile, be boiled in bicarbonate-free water.

6.Mepivacaine hydrochloride(Carbocaine)

• Is similar to lidocaine in its activity profile.

• It has a rapid onset (5–10 minutes).

• Has a somewhat longer duration than lidocaine (120–180 minutes).

• A 2% solution is the most commonly used preparation for infiltration

anesthesia, intra-articular anesthesia, peripheral nerve blocks and

epidural anesthesia.

• It is administered at doses similar to those for lidocaine.

• It is less effective than lidocaine for topical anesthesia.

7.Proparacaine hydrochloride(Ophthaine)

The local anesthetic of choice for topical corneal anesthesia in

horses.

Available as a 0.5% aqueous solution .

When dropped on the cornea it has a rapid onset of action

(within 1 minute) and lasts for about 15-30 minutes.

It is non-irritant

does not affect the size of the pupil.

Intravenous lidocaine

Intravenously administered lidocaine has anesthetic and

analgesic properties.

Lidocaine can be administered IV during anesthesia or to the

awake horse, or in combination with drugs such as ketamine

for analgesia.

The mechanisms underlying systemic lidocaine’s analgesic and

anesthetic actions are not fully understood but it may has a

direct action on spinal transmission

Physiological effects of intravenous lidocaine

• Lidocaine has a number of properties which indicate that it

may be a beneficial drug to administer in association with

general anesthesia or in the awake horse. These include:

Analgesia.

minimum alveolar concentration (MAC )reduction of

volatile anesthetics.

Anti-inflammatory actions. MAC is the concentration of the vapour in the lungs that is

needed to prevent movement (motor response) in 50% of

subjects in response to surgical (pain) stimulus.

Physiological effects of intravenous lidocaine cont..…

Anti-dysrhythmogenic effect.

Reduction of risk of postoperative ileus.

A protection against endotoxemia

A protection against ischemic and reperfusion injury.

Clinical use of intravenous lidocaine

A-As an adjunct to general anesthetics

Used with volatile agents to improve analgesia.

Decrease in MAC is dose-dependent.

Infusion rates of 50 μg/kg/min reduce MAC by ~ 25%.

Infusion rates of 100 μg/kg/min reduce MAC by 40–50%.

Can be infused concurrently with ketamine or alpha2 agonists.

MAC ↓ (60–80%) with ketamine (50 μg/kg/min) and lidocaine

(75 μg/kg/min).

Clinical use of intravenous lidocaine cont.…

B. To provide analgesia in the awake horse

Can be safely infused at 50 μg/kg/min for up to 72 h.

A loading dose (1.5 mg/kg, IV) can be infused over 5 minutes.

A dose of 50 μg/kg/min can be safely infused with ketamine

(0.2 mg/kg/h).

Adverse effects

• The likelihood of systemic toxicity with intravenous

lidocaine is related to its plasma concentration.

A. CNS effects

Low concentrations of lidocaine are sedating.

Increasing concentrations result in muscle twitching

and ataxia.

The horse may become recumbent temporarily.

Administration of sedatives causes a right shift in dose–

response curve.

.

B. Cardiovascular effects

Occur at higher plasma concentrations than do CNS effects.

Result from a delay in impulse transmission by Na channel

blockade. This leads to:

Decreased myocardial contractility.

Vasodilation.

Cardiac dysrhythmias.

Treatment

• Treatment of cardiac toxicity can be

unrewarding.

• It is fairly unresponsive to inotropes (e.g.

dobutamine) and parasympatholytic drugs

(e.g. atropine).

Common methods of producing local anesthesia

1. Surface (topical) anesthesia.

2. Intrasynovial anesthesia.

3. Infiltration anesthesia.

4. Intravenous regional local anesthesia.

1. Topical or surface analgesia

freezing of the superficial layer of the skin by ethyl chloride spray,

carbon dioxide snow or ice.

application of lidocaine oint. on painful eczematous area

instillation of the eye by LA soln as ophthaine or xylocaine 2%

application of lubrication jell contain LAA on the glans penis, vulva and

during urethral catheterization.

instillation in the nasal chamber of the horses

intrasynovial analgesia

-

Instillation analgesiaIndications:Examination of the eyeRemoval of foreign bodiesConjunctival scrapingRemoval of hypertrophied glands of the third eyelidSubconjunctival injectionTopical anesthetics for instillation:Lidocaine 2-5% ,Proparacaine 0.5%Tetracaine 0.5%, Butacaine 0.5%It gives 15 min anesthesia after single instillation and 2hrs after

3-5 series of instillation with one min intervals.

Intrasynovial analgesiaIndicationsDiagnosis of lameness caused by joint disorderTo relief pain caused by arthritisTechnique

Preparation of the site of arthrocentesis for aseptic injection

Insertion of the injection needle intraarticularly

Aspiration of the excessive synovial fluid to prevent excessive

dilution of the LA

Inj of LA dose 5-10 ml according to the size of the joint

The onset of effect begin after 10 min and persist for 60 min.

3.Infiltration anesthesia

1. By this method the nerve endings are affected at the actual site

of operation.

2. Most minor surgery can be done this way, excluding surgery on

teats in cattle or small animal digits.

Indications

Indicated with or without sedation for surgical interference in

ruminant for rumenotomy, C- section, removal of neoplasms,

repair of hernia…

Surgical operations require standing position such as medial

patellar desmotomy.

Diffuse infiltration of the operative area

1.Sensitive tissues: skin, nerve trunks, blood vessels,

periosteum, synovial membrane, mm,near

orifices( mouth, nose, rectum, anus).

2.Insensitive tissues: subcuits, fat, muscles, tendons,

fascia, bone, cartilage, visceral peritoneum.

Advantages

Require no greater skill or the knowledge of the anatomy of the

site.

muscle relaxation and no interference to healing.

Disadvantages

Large volume of LAA in the tissue to be incised and sutured.

Epinephrine in the anesthetic solution may be interfering with the

blood supply and retard healing.

If the flank laparotomy is being done the LA must not only

infiltrated SC but into the fascia and the muscle as well.

Types of infiltration analgesia

1.linear infiltration

2.Inverted "L" or "T" or inverted "V "block

3.field block

4.Ring block

Preparation of the area to be anaesthetized for aseptic

interference.

Define the intended line of the incision by one of the following

methods:

1. scratching of the skin by the tip of the injectable needle

2. intradermal injection of 1 ml of the LA at both ends of the

line to make blebs.

3. using of surgical marker

1.linear infiltration

Area blocked: skin and muscles layers of the flank and parietal

peritoneum along the line of incisions.

Needle: 18 G, 7-10 cm

Anesthetic: 10-100 ml of 2% lidocaine

Methods: make multiple SC injections of 0.5 to 1 ml of AA, 1-2

cm apart then infiltrate the muscle layer and the partial

peritoneum through the desensitized skin.

The inverted red L is the site of inverted L block and the green line is the site of linear infiltration for rumenotomy

Although sensation is mainly confined to the skin, but

in some circumstances it is recommended to

infiltrate the muscular layer beneath the skin as

sensory nerves pass through it and this will achieve

better analgesia,

moreover, involvement of motor nerves that passes

through the muscles reduces movement of the

muscles during incision.

A clear example of this is the linear infiltration of the

left flank in cattle that involves both subcutaneous

tissue and underlying muscles for induction of

rumenotomy or cesarean section.

Advantages:

1-Simple and easy technique

2-It consumes smaller amount of anesthetic and shorter time

than inverted-L technique

Disadvantages:

1-Dealyed healing

2-Changes in the anatomical features

3-Consumption of large amount of drug than paravertebral

4- lack of muscle relaxation

5-incomplete blocking of the deeper layer of the abdominal wall

6-formation of haematoma along the incision line

7-high cost

8-toxicity after inj to peritoneal cavity( more than 250 ml (5g) of 2%

lidocaine.

Linear infiltration analgesia for rumenotomy

2.Field block analgesia1-Cup shape field block:

It is an inverted pyramidal shape analgesic area that is created by two punctures, and can be used when the pass of nerve supply is not exactly known. Usually it is applied to an area of bulky musculature.

Advantages: -

1-Absence of anatomical distortion at seat of incision

2-When the drug contains vasoconstrictor, it will produce efficient ischemia

3-Complete muscular relaxation

4-No retardation of healing

2-Inverted-L block:

It is a field block technique through which only the dorsal and

anterior aspects of the flank region are injected

subcutaneously with LA solution to produce complete

analgesia of the flank ( for rumenotomy or cesarean).

The main point of neglecting the posterior aspect is that the

nerves pass to the flank from the dorsal and anterior aspects

while is passes caudo-ventrally.

Area blocked: flank caudal and ventral to site of injection

Site : a line along the caudal border of the last rib and a long

a line ventral to the lumber transverse process from the last

rib to the 4th lumber vertebra.

Needle: 18 G, 7 cm

Anesthetic: up to 100 ml of 2% lidocaine in adult cattle

The inverted red L is the site of inverted L block and the green line is the site of linear infiltration for rumenotomy

Inverted-L block..cont…

Advantages:

1-Seat of injection is far from incision line (not interfere with healing)

2-Simple technique and requires no technical skills or complicated equipment's

3-It does not cause change of the anatomical features at seat of incision

Disadvantages:

1-It consumes larger amount of anesthetic than linear infiltration and paravertebral

2-It consumes longer time than linear infiltration

3. incomplete block of the deeper layer of the abdominal wall(particularly the

peritoneum).

Inverted-L block

It is a technique used for induction of analgesia by injection of

analgesic drug in a ring manner at one level like in teat or

digit.

INDICATION: The technique is useful for surgical repair of

presternal bursitis in buffalo calves, umbilical hernia,

amputation of digit ,operations of cows teats.

3.Ring block

Vasoconstrictors should not be added on solutions used to

produce ring block in teats, for prolonged vasoconstriction

may results in ischemic necrosis of the end of the teat.

Ring block (olecranon bursitis in buffalo)

( Ring block (umbilical hernia

Intravenous regional local anesthesia(IVRA)1. In this technique, a limb vein is catheterized.

2. The limb is then exsanguinated (Esmarchs bandage), and a tourniquet placed around the limb.

3. Local anesthetic (preferably without epinephrine) is then injected into the vein.

4. After a period of 15 minutes the area distal to the tourniquet is anesthetized until the tourniquet is removed.

5. Intravenous regional anesthesia is commonly used in cattle for amputation of a digit.

6. The analgesic technique is particularly effective in the hind limb.

7. It is also used to a lesser extent for dogs to enable amputation of the digit combined with systemic sedation.

Advantages

No special knowledge of anatomy is needed.

Only one injection is required

Little risk of introducing bacteria

Rapid onset of analgesia( 5-10 min)

Rapid recovery after removal of tourniquet(5-10 min).

IVRAPotential problems of IVRA

1. Difficulty in finding the vein .2. Cardiac arrhythmias or even arrest. This is due to an

inadequate tourniquet.3. Failure to take effect. Common reasons are inadequate

tourniquet, inadequate time, and lack of exsanguinations .4. Collapse when tourniquet is removed. This is because of

anoxic waste products re-entering circulation. It is preferable if the animal is recumbent at this time.

5. Damage as a result of the tourniquet being left on too long. This is rare. It can be left on for 1-1.5 hours on the limb of

cattle and dogs

IVRA (teat surgery)

IVRA

IVRA

Local anesthesia for standing laparotomy in cattle1. infiltration analgesia2. proximal paravertebral anesthesia3. distal paravertebral anesthesia4. segmental dorsolumber epidural anesthesiaAbdominal surgeries in which these anesthetic techniques can be used:

Rumentomy, cecotomy, correction of abomasal

displacement, intestinal obstruction, volvulus,

cesarean section, ovariectomy and liver or kidney

biopsy.

Do you have any questions???