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Ocular anaesthesia
1. Chairperson:
DR. RUBINA YASMIN
ASSOCIATE PROFESSOR
DEPT. OF ANAESTHESIOLOGY
NIO&H
Moderator:
DR. KANIJUN NAHAR QUADIR
ASSISTANT PROFESSOR
DEPT. OF ANAESTHESIOLOGY
NIO&H
Presenter:
DR. NAFIZ MAHMOOD
DO STUDENT
NIO&H
OCULAR
ANAESTHESIA
2. ANAESTHESIA:
Reversible loss of feeling or sensation, specially the loss of pain
sensation induced to permit to performance of surgery or other
painful procedures.
3. From the page of History
Born:
December 3, 1857
Died:
March 21, 1944
Nationality: Austria
Fields: Ophthalmology
Known for:
Cocaine
(a south american bush ERYTROXYLUM COCA.)
as a local anaesthetic in 1884
Ophthalmic surgeon work in Vienna
Karl Koller
4. From the page of History
Born:
March 17, 1832
Died:
April 30, 1911
Hermann Jakob Knapp
In 1884 used cocaine for retrobulbar block.
van Lint achieved orbicularis akinesia by local injection
5. From the page of History
General anaesthesia:
First used by W.T.G Morton of Boston, US
Used – ETHER at Massachusetts General Hospital on 16th
October 1846 to Gilbert Abbott
6. Types of ocular anaesthesia :
General anaesthesia
Local anaesthesia
Topical
Regional
Peribulbar block
Retrofbulbar block
Parabulbar or sub-tenon block
Intracameral block
Facial block
Frontal block
7. PREFERRED ANAESHETIC TECHNIQUE
LOCAL ANAESTHESIA:
• Pterygium
• Cataract
• Surgery for glaucoma
• Minor extra-ocular plastic surgery
• Keratoplasty
• Dacryocystorhinostomy
• Minor anterior segment procedures
• Refractive surgey
• Vitreo-retinal surgery etc
8. GENERAL ANAESTHESIA:
• Paediatric surgery
• Sqint surgery
• Major oculoplastic surgery
• Orbital trauma repair
• Dacryocystorhinostomy
• Vitreo-retinal surgery
9. GENERAL ANAESTHESIA
FOR OCULAR SURGERY
INDICATION:
1. In children and infant
2. Anxious & uncooperative patient
3. Mentally retarded adult
4. Patient’s preference
OBJECTIVE:
1. Analgesia
2. Amnesia
3. Loss of consciousness
4. Adequate skeletal muscle relaxation
10. Advantages:
I. safe operative environment
II. Complete akinesia
III. Controlled intra-ocular pressure
IV. For bi-lateral surgery
V. Avoiding complications of L/A
11. PRE- ANAESTHETIC CHECKUP
GENERAL:
• Nutritional status
• Retarded growth
• Anaemia
• Jaundice
• Cough
• Temperature
• Oedema
• History of convulsion
12. RESPIRATORY SYSTEM :
• Cyanosis
• Dyspnoea
• Auscultation of lung field
AIRWAY:
• Mouth opening
• Neck movement
• Dentition
CARDIOVASCULAR SYSTEM :
• Pulse
• Blood pressure
• Heart sound (auscultation)
• Dependent oedema
14. OTHER INVESTIGATIONS:
S. electrolytes
Liver function test
Coagulation screening
Echocardiogram – specially for congenital heart disease
(valvular disease) also for adult – if indicated
15. Procedure of General Anaesthesia
1) Pre-medication for anaesthesia
2) Induction & intubation
3) Maintenance & Monitoring
4) Extubation and Recovery
16. Drugs used in G/A
1. Pre-medication for anaesthesia with
• Benzodiazepines (diazepam) –for sedation and reduce
anxiety
• Anti-emetics – metaclorpramide , ondansetron
• Atropine - prevent bradycardia
reduce bronchial and salivary secretion
• Medication for selective patients - hypertensive , diabetic ,
coronary artery disease
17. 2.Induction
Thiopentone ( thiopental sodium) – 5 mg/kg
Propofol – 2.5 mg/kg
3. Maintenance
• Muscle relaxants – suxamethonium, vecuronium etc
• anaesthetic gas – nitrous oxide (N2O) with O2 and
Halothene , isoflurane etc.
20. EFFECTS OF ANAESTHETIC AGENTS
ON IOP
DRUGS EFFECT ON IOP
INHALED ANAESTHETICS
Volatile agents
Nitrous oxide
Intravenous agents
Barbiturates
Benzodiazepines
Ketamine
Opioids
MUSCLE RELAXENT
Depolarizers (succinylcholine)
Non- depolarizers
21. LOCAL ANAESTHESIA
ADVANTAGES:
Patient is conscious and alert
Drugs used in G/A can be avoided
Systemic complication is less – Post-operative confusion
Nausea , Vomiting
Urinary retention
Stress response to cardiac patient
acts by producing reversible block to the transmission
of peripheral nerve impulses
22. DISADVANTAGES:
• Painful
• Difficult in uncooperative patients
NOT SUITABLE FOR:
• Young patient
• Mentally unstable patient
• Patient with physical disabilities that prevent lying
23. DESIRED PROPERTIES OF L/A
1. Non-irritating , safe and painless
2. Must be water soluable
3. Rapid onset of action
4. Duration of action appropriate to the operation to be performed
5. Non-toxic
6. No local after effects ( nerve damage , necrosis)
7. Must be effective regardless its application to tissue or mucous
membrane
8. Quickly block motor and sensory nerves
25. MECHANISM OF ACTION OF L/A
Binds with protein of Na+ channels (at interior side)
Block voltage dependent Na+ conductance ( prevent Na+ influx)
Block depolarization
Initiation and propagation of action potential fails
Afferent impulses can not go to higher center
No pain sensation
26. Patient preparation for LA
As for GA
Optimal health condition
Friendly rapport
A suitable vein should always be cannulated in all patient
Full cardio-pulmonary resuscitation equipment
Appropriate monitoring
27. Toxicity of LA:
• Light headedness
• Numbness or tingling of circumoral area
• Anxious
• Drowsy
• Tinnitus
• Convulsion ( To prevent- Diazepam or TPS)
• Coma & apnoea develop subsequently (O2)
• Cardiovascular collapse may result due to myocardial depression &
vasodilatation
HYPOXAEMIA APNOEA
28. Types of LA
According to chemical structure
Ester group Amide group
Procaine
Cocaine
Tetracaine
benzocaine
Lidocaine
Bupivacaine
Ropivacaine
mepivacaine
Esters may cause more allergies
29. COMMONLY USED L/A
L/A Onset of
action
Duration of
action
Use
(concentration)
Oxybuprocaine 6-20 sec 15 min Topical (0.4%)
Lignocaine
5-10 min
10- 35 sec
30-60 min
15-20 min
Infiltration
(1%,2%,4%)
Topical (4%)
Bupivacaine Moderate 75-90 min Infiltration (0.25-
0.75%)
30. OTHERS
L/A Onset of
action
Duration of
action
Use
(concentration)
Proparacaine 15-30 sec 15-20 min Topical (0.5%)
Amethocaine 10-25 sec 10-20 min Topical (0.5-1%)
Ropivacaine Moderate 1.5-6hrs Infiltration (1%)
31. TOPICAL ANAESTHESIA
ADVANTAGES:
Cost effective
Immediate visual recovery
Avoidance of complication - globe rupture , nerve damage
DISADVANTAGES:
No akinesia
Not suitable for extended surgery
Well informed and motivated patient is required
32. ADVERSE EFFECT OF TOPICAL ANAESTHESIA
• Epithelial and Endothelial toxicity
• Allergy to drug
• Alteration of lacrimation
• Surface keratopathy
33. USES OF TOPICAL ANAESTHESIA
• Manipulation of superficial cornea and conjunctiva
• Phacoemulsification in cooperative patient
• Prior to regional blocks
34. PERIBULBAR BLOCK
Most popular now a days
AIM:
Injected into peribulbar space
Spreads to lid and other spaces
Produces globe and orbicularis akinesia and anaesthesia.
L/A agent :
o Lignocaine 2%
o Bupivacaine 0.75%
Along with
o Hyaluronidase 5-7.5 IU/ml
o Adranaline 1: 200,000
35. VOLUME :
8-10 ml (approximately)
INSERTION POINT:
• 1st - Junction of medial 2/3rd and lateral 1/3rd of lower lid adjacent
& Parallel to orbital floor
• 2nd - Just infero-medial to supra orbital notch or just medial to
medial canthus
36. POSITION OF PATIENT:
Supine and in primary gaze
USE OF PERIBULBAR BLOCK
1. Cataract
2. Glaucoma
3. Keratoplasty
4. Vitreoretinal surgery
5. Strabismus surgery
37. ADVANTAGES:
• Less chance of globe injury
• Less chance of optic nerve damage
DISADVANTAGES:
• Pain
• Conjunctival chemosis
• Less akinesia than retrobulbar block
38. RETROBULBAR BLOCK
AIM:
Injected in muscle cone to block
• Cilliar nerve and ganglion
• 3rd , 4th & 6th cranial nerves
• provides - akinesia and
anaesthesia of the globe.
POSITION OF PATIENT:
Supine and in primary gaze
SITE OF INJECTION:
In the lower lid margin just above a point between medial
2/3rd & lateral 1/3rd of lower orbital margin
39. DIRECTION OF NEEDLE:
backward , upwards and medially towards apex of orbit
VOLUME:
2 – 4 ml usually
ADVANTAGES:
• Complete akinesia
• Dilatation of pupil
• Adequate and quicker anaesthesia
• Minimal amount of agent required
42. Contraindication :
• Bleeding disorder ( risk of retrobulbar haemorrhage)
• Extreme myopia ( globe perforation)
• An open eye injury (may cause expulsion of intraocular contents)
• Posterior staphyloma
43. PARABULBAR OR SUB-TENON BLOCK
Conjunctival incision 2-3 mm
Halfway between inf. limbus & fornix
to open sub-tenon space
Blunt canulla or needle is inserted to post. Sub-tenon space
Bathing the nerves & muscles within the cone
DRUG : LIGNOCAINE
45. ADVANTAGES:
• Avoid vascular and optic nerve injury
• Requires lower volume of anaesthetics
• Better anaesthesia to iris and ant.segment
DISADVANTAGES:
• Subconjunctival haemorrhage
• More post-operative morbidity
46. FRONTAL BLOCK
AIM: to block supra-orbital and supra-trochlear nerve
supplying the upper lid.
USE: ptosis surgery
SITE OF INSERTION: just below mid-point of supra- orbital
margin transcutaneously
directed towards roof of orbit
VOLUME: about 2 mlw
48. FACIAL BLOCK
AIM: blocking the action
of orbicularis oculi.
USE : as an adjunct to
retrobulbar block.
TYPES:
1. Van lint
2. O’Brien
3. Nadbath & Rehman
4. Atkinson
49. Major sight and life-threatening complications
A. Retrobulbar orbital haemorrhage
SIGNS & SYMPTOMS
• rapid intraorbital and intraocular pressure elevation
• increasing proptosis
• marked pain
• ecchymoses in the eyelids
• Chemosis
• vision down to poor perception or no perception of light
50. MANAGEMENT:
Evaluation:
Indirect ophthalmoscopy - for evidence of central retinal artery
perfusion compromise.
Immediate medical treatment:
intravenous osmotic agents such as –
• acetazolamide
• mannitol
52. B. Globe perforation:
(Exceptionally soft eye ; myopic eye is more prone)
• Occurred with retrobulbar and peribulbar anaesthesia
• suspected if –
marked pain during the delivery of local an aesthesia
hypotony with inability to secure a stable globe - intraoperative signs of
perforation
reduced red reflex due to vitreous haemorrhage
Serious sight threatening vitreoretinal complications may result
**** seek the advice of a specialist vitreoretinal surgeon
53. C. Nerve Injury
Optic nerve may be damaged by:
●● direct trauma by needle
●● ischaemic damage from intrasheath injection or haemorrhage
●● pressure from retrobulbar haemorrhage
●● pressure from excess local anaesthetic injection into the
retrobulbar space
●● excessive applied external pressure.
54. NEED TO CARE :
• avoiding deep injections into the orbit and
• injecting with the eye in the primary position
55. D. Brain stem anaesthesia
Due to spread of local anaesthetic along the optic nerve sheath
SYMPTOMS & SIGNS:
• drowsiness
• light-headedness
• confusion
• loss of verbal contact
56. • cranial nerve palsies
• convulsions
• respiratory depression or respiratory arrest
• cardiac arrest
ONSET OF SYMPTOMS: within 10-20 mins of LA injection
SYMPTOMS LASTS FOR: Hours
57. E. Muscle palsy
Diplopia and ptosis are common for 24–48 hours post-operatively
when large volumes of long-acting local anaesthetics are used.
If this persists or fails to recover, it may be due to muscle damage
as a result of :
• intramuscular injection of local anaesthetics
• local anaesthetic myotoxicity
• ischaemic contracture following haemorrhage/trauma
58. F. Oculocardiac Reflex (Trigeminovagal reflex)
Trigeminal nerve – afferent and vagal efferent pathway
CAUSES:
• Traction on extra-ocular muscle
• Pressure on globe
RESULT:
Bradycardia
Ventricular ectopy
Ventricular fibrilation
59. AFFERENT PATHWAY
Impulses
Long & short cilliary nerve
Cilliary ganglion
Trigeminal gasserian ganglion
main trigeminal sensory nucleus
in the floor of the 4th ventricle
61. Treatment
• Stop the surgical stimulus immediately.
• Ensure adequate ventilation .
• Ensure sufficient anesthetic depth.
Atropine / Glycopyrrolate (anti-cholinergic):
often helpful immediately or prior surgery
62. TAKE HOME MESSAGES
• All local anaesthetic agents are myotoxic
• Direct injection into a muscle should be avoided
• No LA technique is entirely free of severe systemic adverse events
• short, fine needle should be used
• the eye in the primary gaze position (looking straight ahead)
• Gentle aspiration after insertion of needle should be done to
alleviate possible entry to blood vessel.
• Bevel of the needle facing the globe and tangenital to sclera.
• All occular surgery with LA should be treated as GA.