BrAVO 2006 EAG Ophthalmic Treasures

7/30/2019 BrAVO 2006 EAG Ophthalmic Treasures

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Regional Anesthesia as anRegional Anesthesia as an

Adjunct to Eyelid SurgeryAdjunct to Eyelid Surgery

Elizabeth Giuliano, DVM, MSElizabeth Giuliano, DVM, MS

Diplomate, ACVODiplomate, ACVO


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Local AnesthesiaLocal Anesthesia

Produce desensitization and analgesia of local tissuesProduce desensitization and analgesia of local tissues

May be used as an adjunct to intravenousMay be used as an adjunct to intravenous

and inhalation anesthesiaand inhalation anesthesia

My personal uses in ophthalmic surgery:My personal uses in ophthalmic surgery:

EnucleationEnucleation

Eyelid surgeryEyelid surgery

CanthoplastyCanthoplasty, entropion/ectropion, wedge resection,, entropion/ectropion, wedge resection,

laceration repairlaceration repairEspecially helpful in entropion repairs where anatomicEspecially helpful in entropion repairs where anatomic

component is minimal butcomponent is minimal but spasticspastic component greatcomponent great

PostPost--operative cataract patient IOP checks whereoperative cataract patient IOP checks where

canthotomy was performedcanthotomy was performed

Lidocaine + Bupivicaine


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Local AnesthesiaLocal Anesthesia -- DrugsDrugs

Chemical Group:Chemical Group:

AmideAmide (lidocaine, mepivicaine, bupivicaine)(lidocaine, mepivicaine, bupivicaine)

Reversible depression of nerve conduction by blockingReversible depression of nerve conduction by blockingsodium channelssodium channels

Prevents rapid influx of sodium ions into nerve axonPrevents rapid influx of sodium ions into nerve axonand production of action potentialand production of action potential local musclelocal muscleparalysis and analgesiaparalysis and analgesia

Metabolized by the liverMetabolized by the liver

EstersEsters (procaine, cocaine,(procaine, cocaine, chloroprocainechloroprocaine,,tetracainetetracaine))

Metabolized by enzyme calledMetabolized by enzyme calledpp--aminobenzoicaminobenzoic acidacid

Caution in patients with reduced cholinesterase activityCaution in patients with reduced cholinesterase activity(newborn, pregnant)(newborn, pregnant)


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Local AnesthesiaLocal Anesthesia -- ToxicityToxicity

Toxicity:Toxicity:

CNSCNS

Most common in areas with large blood vesselsMost common in areas with large blood vessels(i.e. epidurals)(i.e. epidurals)

CNS toxicity (e.g. seizures) usually occur beforeCNS toxicity (e.g. seizures) usually occur beforecardiovascular toxicitycardiovascular toxicity

TxTx: diazepam for seizures & oxygen/supportive: diazepam for seizures & oxygen/supportive

measures until drugs metabolizedmeasures until drugs metabolized

CardiovascularCardiovasculararrhythmias, vasodilation,arrhythmias, vasodilation,hypotension, cardiac arresthypotension, cardiac arrest

Wound healingWound healingdelayed with large volumesdelayed with large volumes


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Local AnesthesiaLocal Anesthesia -- ToxicityToxicity

Do not exceed toxic doseDo not exceed toxic dose

Lidocaine (Abbott Laboratories, other sources alsoLidocaine (Abbott Laboratories, other sources alsoavailable)available) Rapid onset (2 minutes)Rapid onset (2 minutes)

Short duration of action (20 minutesShort duration of action (20 minutes2 hours)2 hours) Can be prolonged by addition of epinephrine at 1:200,000 orCan be prolonged by addition of epinephrine at 1:200,000 or

1:400,0001:400,000

Toxic IV dose: 10Toxic IV dose: 10--20 mg/kg ( I use 5 mg/kg )20 mg/kg ( I use 5 mg/kg )

Bupivicaine (Bupivicaine (MarcaineMarcaine, Abbott Laboratories), Abbott Laboratories) Slow onset (3Slow onset (3--6 minutes)6 minutes)

Long duration of action (4Long duration of action (4--6 hours)6 hours) Can be prolonged by addition of epinephrine at 1:200,000 orCan be prolonged by addition of epinephrine at 1:200,000 or

1:400,0001:400,000

Toxic dose: 2Toxic dose: 2--3 mg/kg ( I use 1.5 mg/kg )3 mg/kg ( I use 1.5 mg/kg )


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How much? Examples:How much? Examples:

45 mg

9 ml

6 ml

15 mg

3 ml

2 ml

7.5 mg

1.5 ml

1 ml

Bupivicaine

(1.5 mg/kg) *

0.5%=5mg/ml

0.75%=7.5 mg/ml

150 mg

7.5 ml

50 mg

2.5 ml

25 mg

1.25 ml

Lidocaine

(5 mg/kg) *

2%=20 mg/ml

30 kg10 kg5 kg

Weight

vs

Dose


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Enucleation Surgery

Retrobulbar block (JAVMA paper)

Regional eyelid infusion & splash block


8/22

Local AnesthesiaLocal Anesthesia Retrobulbar BlockRetrobulbar Block

Development of a retrobulbar injection technique forDevelopment of a retrobulbar injection technique for

ocular surgery and analgesia in dogs.ocular surgery and analgesia in dogs.

AccolaAccola PJ, Bentley E, Smith LJ, et al.PJ, Bentley E, Smith LJ, et al.

J Am Vet Med Assoc.J Am Vet Med Assoc. 2006 Jul 15;229(2):2202006 Jul 15;229(2):220--5.5.

OBJECTIVE: To develop and compare 3 techniques forOBJECTIVE: To develop and compare 3 techniques for

retrobulbar injection of local anesthetic agents forretrobulbar injection of local anesthetic agents for

ocular surgery and analgesia in dogs.ocular surgery and analgesia in dogs.

DESIGN: Prospective study.DESIGN: Prospective study.

ANIMALS: 17 dogs (including 9 cadavers).ANIMALS: 17 dogs (including 9 cadavers).


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Local AnesthesiaLocal Anesthesia Retrobulbar BlockRetrobulbar Block

Development of a retrobulbar injection technique for ocular surgDevelopment of a retrobulbar injection technique for ocular surgery andery and

analgesia in dogs.analgesia in dogs. AccolaAccola PJ, Bentley E, Smith LJ, et al.PJ, Bentley E, Smith LJ, et al. J Am Vet Med Assoc.J Am Vet Med Assoc.2006 Jul 15;229(2):2202006 Jul 15;229(2):220--5.5.

PROCEDURES: InferiorPROCEDURES: Inferior--temporal palpebral (ITP),temporal palpebral (ITP),

perimandibularperimandibular, and combined superior, and combined superior--inferiorinferiorperibulbarperibulbar

injection techniques were compared by assessing theinjection techniques were compared by assessing the

distribution of latex after injection into the orbits of 5distribution of latex after injection into the orbits of 5

canine cadavers;canine cadavers;


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analgesia in dogs.analgesia in dogs. AccolaAccola PJ, Bentley E, Smith LJ, et al.PJ, Bentley E, Smith LJ, et al. J Am Vet Med Assoc.J Am Vet Med Assoc.

2006 Jul 15;229(2):2202006 Jul 15;229(2):220--5.5.

PROCEDURES:PROCEDURES: magnetic resonance imaging (MRI)magnetic resonance imaging (MRI)

evaluation of the distribution of contrast agent after injectionevaluation of the distribution of contrast agent after injectionin the retrobulbar space of 4 canine cadavers; & assessmentin the retrobulbar space of 4 canine cadavers; & assessment

of the efficacy and MRI evaluation of the anatomicof the efficacy and MRI evaluation of the anatomic

distribution of injections of a lidocaine contrast agentdistribution of injections of a lidocaine contrast agent

mixture in 4 anesthetized,mixture in 4 anesthetized, nonrecoverynonrecovery dogs.dogs.


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analgesia in dogs.analgesia in dogs. AccolaAccola PJ, Bentley E, Smith LJ, et al.PJ, Bentley E, Smith LJ, et al. J Am Vet Med Assoc.J Am Vet Med Assoc.

2006 Jul 15;229(2):2202006 Jul 15;229(2):220--5.5.

PROCEDURES: By use of the preferred technique (ITP), thePROCEDURES: By use of the preferred technique (ITP), the

ocular effects of lidocaine anesthesia were evaluated in 4ocular effects of lidocaine anesthesia were evaluated in 4

dogs; during a 2dogs; during a 2--week period after treatment, dogsweek period after treatment, dogs

underwent ophthalmic examination, Schirmer tear testingunderwent ophthalmic examination, Schirmer tear testing

(STT), intraocular pressure (IOP) measurement, and(STT), intraocular pressure (IOP) measurement, andCochetCochet--

BonnetBonnet esthesiometryesthesiometry..


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Development of a retrobulbar injection technique for ocular surgDevelopment of a retrobulbar injection technique for ocular surgery and analgesia in dogs.ery and analgesia in dogs.

AccolaAccola PJ, Bentley E, Smith LJ, et al.PJ, Bentley E, Smith LJ, et al. J Am Vet Med Assoc.J Am Vet Med Assoc. 2006 Jul 15;229(2):2202006 Jul 15;229(2):220--5.5.

RESULTS: Of the 3 techniques, the ITP technique was theRESULTS: Of the 3 techniques, the ITP technique was the

preferred method for because it was efficacious (pupilpreferred method for because it was efficacious (pupil

dilation and central rotation of the globe achieved in alldilation and central rotation of the globe achieved in alleyes), easiest to perform, and provided thorough coverage ofeyes), easiest to perform, and provided thorough coverage of

the intraconal retrobulbar space without complication.the intraconal retrobulbar space without complication.

During the 2During the 2--week followweek follow--up period, the ITP injection didup period, the ITP injection did

not significantly affect STT, IOP, ornot significantly affect STT, IOP, orCochetCochet--BonnetBonnet

esthesiometryesthesiometry values in dogs.values in dogs.


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Development of a retrobulbar injection technique for ocular surgDevelopment of a retrobulbar injection technique for ocular surgery and analgesia in dogs.ery and analgesia in dogs.

AccolaAccola PJ, Bentley E, Smith LJ, et al.PJ, Bentley E, Smith LJ, et al. J Am Vet Med Assoc.J Am Vet Med Assoc. 2006 Jul 15;229(2):2202006 Jul 15;229(2):220--5.5.

CONCLUSIONS AND CLINICAL RELEVANCE: InCONCLUSIONS AND CLINICAL RELEVANCE: In

dogs, retrobulbar administration of anesthetic agents viadogs, retrobulbar administration of anesthetic agents viathe ITP technique is a potential alternative to systemicthe ITP technique is a potential alternative to systemicadministration of neuromuscular blocking agents foradministration of neuromuscular blocking agents forophthalmic surgery and provides the additional benefit ofophthalmic surgery and provides the additional benefit oflocal ocular analgesia.local ocular analgesia.

******

TF Evans, PDTF Evans, PD dada Costa.Costa.

MedialMedial PeribulbarPeribulbar(MPB) Nerve Block for Corneal and(MPB) Nerve Block for Corneal andIntraocular Surgery in the Dog.Intraocular Surgery in the Dog.

ACVO 37ACVO 37thth Annual Conference, 2006,Annual Conference, 2006, ProceedingsProceedingspg 1pg 1


14/22

Enucleation Surgery

Retrobulbar block (JAVMA paper)

Regional eyelid infusion & splash block


15/22

Enucleation Surgery


16/22

Annabella, 2 y.o. Shar Pei with entropion OU


17/22

Annabella, 2 y.o. Shar pei with entropion OU, intra-op


18/22

Annabella, 2 y.o. Shar pei with entropion OU, intra-op

Small gauge needle: 25 or 27


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5 hours post-opRepaired via an upper and lower Hotz-Celsus,

arrow-head modification and lateral canthal

tendonotomy OU


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5 hours post-op

Useful space occupying effect for spastic component

Important to keep ocular surface well lubricated


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BrAVO 2006 EAG Ophthalmic Treasures