anaesthesia for ophthalamic surgery and complications

1. ANESTHESIA FOR
OPHTHALMIC SURGERY
AND COMPLICATIONS
SHADAB

2. INTRODUCTION
 Anesthesia for EYE surgery presents many
unique challenges.
 In addition to possessing technical
expertise, the anesthesiologist must have
detailed knowledge of ocular anatomy,
physiology, and pharmacology.

3. INTRODUCTION
 Ocular anatomy
 Physiology of intraocular pressure and effect
of anesthetic drug on it,
 Systemic effects of ophthalmic drugs
 Technique of anaesthesia: advantage and
limitations
 Pre op evaluation
 General anaesthesia
 Complications
 Oculocardiac reflex and other reflex
 Specific considerations for eye surgeries

4. Ophthalmic Surgery
Challenges for the anaesthesiologist are
 Akinesia
 Analgesia
 Minimal Bleeding
 Awareness of drug interactions
 Regulation of intraocular pressure
 Prevention of the oculocardiac reflex
 Management of oculocardiac reflex
 Control of intraocular gas expansion
 Smooth emergence

5. Ophthalmic Surgery
Why these patient have a particular challenge to
the anesthesiologist?
 The combination of a full stomach and an open-
globe injury, both of which conditions are
problematic for the anesthesiologist.
 Any drug or manoeuvre that raises intra-ocular
pressure (lOP) can cause extrusion of the
vitreous humor and loss of vision.

6. Ocular Anatomy

7. APPLIED ANATOMY OF THE
ORBIT

8. APPLIED ANATOMY OF THE
ORBIT
The orbit
♦ Four-sided bony pyramid
♦ Base pointing anteriorly
♦ Apex posteromedialiy.
♦ The medial wall of the right and left orbits
are parallel to each other
♦ The mean distance from the inferior orbital
margin to The apex is 55 mm. (This has
important implications when injections are
made into the orbit.)

9. APPLIED ANATOMY OF THE
ORBIT
 Movement of the globe is controlled by the six
extra-ocular muscles.
 The eye is hollow sphere with a rigid wall.
 Intraocular pressure 12—20 mmHg
 Ophthalmic surgery can be intraocular or
extraocular procedures, each has different
anaesthetic requirements.

10. APPLIED ANATOMY OF THE
ORBIT
Squeezing and closing of the eyelids
 These are controlled by the zygomatic branch
of the facial nerve (VII), which supplies the
motor innervation to the orbicularis oculi
muscle.
 The facial nerve also supplies secretomotor
parasympathetic fibres to the lacrimal glands,
and glands of the nasal and palatine mucosa.

11. APPLIED ANATOMY OF THE
ORBIT
How is aqueous humor formed and eliminated?
 a clear fluid that occupies the anterior and
posterior chambers of the eye.
 Its total volume is 0.3 ml.
 produced primarily in the posterior chamber
 circulates through the pupil to the anterior
chamber, passes through the Schlemmn’s
canal.
 drains into the episcleral veins and finally into
the cavernous sinus or jugular venous sinus.

12. Physiology of IntraocuIar
Pressure

13. Physiology of IntraocuIar
Pressure
 The eye is hollow
sphere with a rigid
wall.
 intraocular pressure
12—20 mm Hg
 If the contents of the
sphere increase, the
intraocular pressure
rise.

14. Physiology of IntraocuIar
Pressure

15. Physiology of IntraocuIar
Pressure
Any anaesthetic event that alters these
parameters can affect intraocular pressure
 Laryngoscopy
 Intubation
 Airway obstruction
 Coughing
 Trendelenburg position

16. Effect of Anesthetic Drugs
on intraocuIar Pressure

17. Effect of Anesthetic Drugs
 Most anesthetic drugs either lower or
have no effect on intraocular pressure

18. Inhaled Anesthetics
 Inhalational anesthetics decrease
intraocular pressure in proportion to the
depth of anesthesia.
 The decrease has multiple causes:
1. A drop in blood pressure reduces
choroidal volume
2. Relaxation of the extraocular muscles
lowers wall tension
3. pupillary constriction facilitates aqueous
outflow.

19. Intravenous anesthetics
 Intravenous anesthetics drugs decrease
intraocular pressure
 Exception is ketamine, which usually raises
arterial blood pressure and does not relax
extraocular muscles.

20. Muscle relaxants
 Succinylcholine increases intraocular
pressure by 5—10 mm Hg for 5—10
minutes principally through prolonged
contracture of the extraocular muscles.
 Nondepolarizing muscle relaxants do not
increase intraocular pressure.

21. The effect of anesthetic agents
on intraocular pressure (lOP).

22. SYSTEMIC EFFECTS
OF OPHTHALMIC DRUGS

23. SYSTEMIC EFFECTS
OF OPHTHALMIC DRUGS
 Topical ophthalmic drugs can be
absorbed through the conjunctiva, or they
drain through the nasolacrimal duct and
be absorbed through the nasal mucosa.
 Usage of topical medications can have
implications for the anesthesiologist.

24. SYSTEMIC EFFECTS
OF OPHTHALMIC DRUGS
Atropine
 Used to produce mydriasis and
cyclopiegia.
 The 1% solution contains 0.2 to 0.5 mg of
atropine per drop.
 Systemic reactions, include tachycardia,
flushing, thirst, dry skin, and agitation.
 Atropine is contraindicated in closed-angle
glaucoma.

25. SYSTEMIC EFFECTS
OF OPHTHALMIC DRUGS
Scopolamine
 One drop of the 0.5% solution has 0.2 mg of
scopolamine.
 CNS excitement can be treated with
physostigmine, 0.015 mg/kg IV, repeated
one or two times in a 15- minute period.
 It is contraindicated in closed-angle
glaucoma.

26. SYSTEMIC EFFECTS
OF OPHTHALMIC DRUGS
Phenylephrine Hydrochloride
 Phenylephrine hydrochloride is used to
produce capillary decongestion and
pupillary dilatation.
 Applied to the cornea, it can cause
palpitations, nervousness, tachycardia,
headache, nausea and vomiting, severe
hypertension, reflex bradycardia, and
subarachnoid hemorrhage.
 Solutions of 2.5%, 5%, and 10% (6.25 mg
phenylephrine per drop) are available.

27. SYSTEMIC EFFECTS
OF OPHTHALMIC DRUGS
Epinephrine
 Topical 2% epinephrine will decrease
aqueous secretion, improve outflow, and
lower intraocular pressure in open-angie
glaucoma.
 Side-effects include hypertension,
palpitations, fainting, pallor, and
tachycardia.
 The effects last about 15 minutes.
 One drop of 2% solution contains 0.5 to 1
mg of epinephrine.

28. SYSTEMIC EFFECTS
OF OPHTHALMIC DRUGS
Timolol Maleate (Tinwptic)
 Timolol maleate is a beta-blocker used in
the treatment of chronic glaucoma.
 Side- effects include light-headedness,
fatigue, disorientation, depressed CNS
function, and exacerbation of asthma.
Bradycardia, bronchospasm, and
potentiation of systemic beta-blockers can
occur.

29. SYSTEMIC EFFECTS
OF OPHTHALMIC DRUGS
Acetylcholine
 Acetylcholine can be injected
intraoperatively into the anterior chamber
to produce miosis.
 Side-effects are due to its parasympathetic
action they include hypotension,
bradycardia, and bronchospasm.

30. SYSTEMIC EFFECTS
OF OPHTHALMIC DRUGS
Echothiophate Iodide (Phosplzolfne Iodide)
 A cholinesterase inhibitor, echothiophate
iodide is used as a miotic agent.
 prolong the effect of both succinyicholine
and ester-type local anesthetics.
 Levels of pseudocholinesterase decrease
by 80% after 2 weeks on the drug.
 Succinyicholine and ester-type local
anesthetics should be avoided.

31. Anesthesia for
Ophthalamic Surgery

32. TECHNIQUES OF ANESTHESIA
 Facial nerve block
 Retrobulbar block
 Peribulbar block
 Sub Tenon block
 Topical anesthesia
 General anesthesia

33. GENERAL VERSUS LOCAL
ANESTHESIA
 The choice of general versus local
anesthesia is made on the basis of
the duration of the surgery,
the relative risks and benefits of each
technique for the patient,
patient preference.
 Neither technique has been shown to be
safer.

34. General versus Local
Anesthesia
General
Anesthesia:
Patient
refusal
Children /
movement
disorders
Major /
lengthy
procedures
Inability to
lie still / flat
Local
Anesthesia:
No Physio-
logical
distur-
bance ,
PONV
Economic,
Day care
Regional
Anesthesia:
Good
akinesia
and
anaesthe
sia
Minimal
effect on
IOP
Minimal
equipme
nt
required
Topical
Anesthesia:
no risk of
hemorrhage,
brainstem
anesthesia,
optic nerve
damage or
globe
perforation

35. LIMITATIONS…
General Anesthesia:
Eye surgery
necessitates
positioning the
anesthesiologist
away from the
patient’s airway
Patients at extremes
of age
Pediatric patients :
associated
congenital disorders
(eg: rubella
syndrome, Down
syndrome).
Co-morbidity in
elderly: esp. Diabetes,
hypertension and
coronary artery
disease
Ophthalmic drugs
Local Anesthesia:
Complications ,
Allergy to drug
Skill of
anaesthetist
Shortness of
breath on lying
down, chronic
cough
Parkinson’s
disease
Eye Trauma
Topical
Anesthesia:
lack of eye
akinesis
treatment
of
uncomplic
ated
cataracts
only

36. PREOPERATIVE EVALUATION
 Eye surgery patients are a high-risk group
 Extremes of Age
 Other risk factors, such as diabetes,
hypertension, and atherosclerosis
 The anesthesiologist's goal is to prepare
the patient to present an acceptable risk
at surgery.
 Acceptable risk is determined by the
medical care team with the informed
consent of the patient.

37. HISTORY
 Previous hospitalizations and surgical
procedures Allergies and drug
sensitivities
 A current list of medications
 Patient factors that could influence
anesthetic management include
dementia, deafness, language difficulty,
restless legs syndrome, obstructive sleep
apnea, tremors, dizziness, and
claustrophobia.

38. PHYSICAL EXAMINATIONS
 Check for signs of major cardiac or
pulmonary decompensation.
 Particular attention should be paid to
positioning issues, such as severe
scoliosis or orthopnea.

39. CARDIOVASCULAR
EVALUATION
 The American Heart Association and
American College of Cardiology published
guidelines for perioperative cardiovascular
evaluation for noncardiac surgery.
 Ophthalmic procedures such as cataract
extraction are specifically identified as
low-risk procedures.
 For these procedures, evaluation is focused
on patients with major clinical predictors of
risk.

40. HYPERTENSION
 Severe hypertension may lead to
perioperative complications.
 It would be prudent to reschedule elective
procedures in patients with sustained stage
3 hypertension until after 2 weeks of
antihypertensive therapy.

41. PULMONARY
CONSIDERATIONS
 Ophthalmic procedures generally require
that the patient lie flat comfortably and
quietly.
 Preoperative risk reduction strategies include
cessation of cigarette smoking, treatment of
airflow obstruction with bronchodilators or
steroids, and administration of antibiotics for
respiratory infections.
 Patients should be assessed for sleep apnea.
Intravenous sedation is often contraindicated
in these patients.

42. ENDOCRINE
CONSIDERATIONS
 Severe hyperglycemia and hypoglycemia
should be avoided.
 A fasting blood glucose should be
checked preoperatively.
 Insulin therapy should be used, if needed,
to maintain blood glucose at 150 to
250 mg/dL.
 The potential for autonomic neuropathy
needs to be considered, especially when
elevating the patient from the supine
position.

43. ENDOCRINE
CONSIDERATIONS
 Patients on long-term steroid therapy
generally do not require “stress-dose”
steroid treatment for ophthalmic surgery.
 The patient should be given his or her
normal steroid dose on the day of
surgery.
 Unexpected hypotension, fatigue, and
nausea may be signs of a patient who
needs additional steroid

44. ANTICOAGULATION
 Perioperative management of anticoagulants
involves weighing the relative risks of
thrombotic against possible hemorrhagic
complications. That depends on the
following:
The degree of anticoagulation.
 The hemorrhagic potential of the surgical
procedure as in orbital and oculoplastic
surgery; of intermediate probability in
vitreoretinal, glaucoma, and corneal
transplant surgery; and least likely in
cataract surgery.

45. INVESTIGATIONS
 Electrocardiogram: New chest pain,
decreased exercise tolerance, palpitations,
near-syncope, fatigue, or dyspnea.
Tachycardia, bradycardia, or irregular
pulse on examination.
 Serum electrolytes: History of severe
vomiting or diarrhea, poor oral intake,
changes in diuretic management, or
arrhythmia. Critical results: Sodium less than
120 mEq/L or greater than 158 mEq/L.
Potassium less than 2.8 mEq/L or greater
than 6.2 mEq/L.

46. INVESTIGATIONS
 Urea nitrogen: Signs or symptoms of renal
decompensation. Critical result: Greater than
104 mg/dL.
 Serum glucose: Polydipsia, polyuria, or weight
loss. Critical results: Less than 46 mg/dL or
greater than 484 mg/dL.
 Hematocrit/hemoglobin: History of bleeding,
poor oral intake, fatigue, decreased exercise
tolerance, or tachycardia. Critical results:
Hematocrit less than 18% or greater than 61%.
Hemoglobin less than 6.6 mg/dL or greater than
19.9 mg/dL

47. GENERAL ANESTHESIA
PREMEDICATION
 An effective antiemetic should be used to
decrease PONV. Eg- Ondansetron
 Opioids are avoided as they contribute to
PONV.
 Benzodiazepines are given.

48. Pretreatment regimens to
control the sympathetic
response to tracheal intubation:
 i.v. lidocaine (1.5 mg/kg)
 i.v. remifentanil(0.5 to 0.1 µg/kg)
 i.v. fentanyl (1 to 3 µg/kg) 3 to 5 minutes
before induction.
 i.v alfentanil (20 µg/kg)
 Oral clonidine (5 µg/kg) 2 hours before
induction

49. GENERAL ANESTHESIA
INDUCTION
 The choice of induction technique for
eye surgery usually depends more on
the patient’s medical problems
the patient’s eye disease
the type of surgery contemplated.

50. GENERAL ANESTHESIA
 Intravenous agents: Propofol , Thiopental
and Etomidate.
 Volatile Agents: can be used, minimal
PONV.
 Coughing during intubation: avoided by a
deep level of anesthesia and profound
paralysis.
 The IOP response: to laryngoscopy and
endotracheal intubation can be blunted.
 LMA: can also be used. Less changes in
IOP.

51. AIRWAY MANAGEMENT
 For measurement of intraocular pressure
(IOP)- maintenance of spontaneous
respiration via a facemask should be used,
as intubation will raise the intraocular
pressure.
 Examination under anaesthesia (EUA)-
spontaneous respiration through a
reinforced laryngeal mask airway (LMA)
 It has the advantages of reduced coughing
at the end of the surgery and controlled
ventilation with the use of muscle relaxants
is possible.

52. AIRWAY MANAGEMENT
 Intraocular surgery requires a still eye with
low intraocular pressure and the airway is
best managed by intubation with paralysis
and controlled ventilation.
 Access to the airway will be restricted during
the surgery so it is important to secure the
tracheal tube firmly.
 A preformed south facing RAE tube is ideal,
but this may be too long in neonates; a
reinforced flexible tracheal tube (ETT) may
be preferable in this situation.

53. GENERAL ANESTHESIA
RELAXATION-
 A nondepolarising muscle relaxant is used
instead of succinylcholine because the
latter increases intraocular pressure.
 However, the rise in IOP is small by
succinylcholine than the fall caused by
intravenous induction agent, and also
considering risk of aspiration
succinylcholine can be used in an
emergency case.

54. MAINTENANCE
 Where halothane is used there is an increased
risk of dysrhythmias, particularly where eye
preparations containing atropine or
adrenaline are used, and in the presence of
hypercapnia.
 Isoflurane or sevoflurane may be preferable.
 Total intravenous anaesthesia (TIVA) with
propofol has advantages in reducing the risk
of postoperative nausea and vomiting (PONV)
since propofol has anti-emetic effects.
 Remifentanil can reduce volatile
requirements.

55. USE OF NITROUS OXIDE
 The use of nitrous oxide in eye surgery is
limited by two factors.
 Increase the risk of PONV, and in
ophthalmic procedures there is a high
incidence of PONV
 Secondly, nitrous oxide diffuses from the
blood into gas filled spaces in the body.
 It should be avoided in vitreoretinal
detachment surgery where intraocular gas
bubbles of sulphur hexachloride or
perfluropropane are introduced into the
eye to tamponade detached surfaces.

56. Effect of intraocular gas
expansion
 If nitrous oxide is used for a patient who has
had recent vitreoretinal surgery (the bubble
may last several weeks), or if it is commenced
mid procedure, it can cause a significant rise
in intraocular pressure with resultant
ischaemic damage.
 Alternatively, if nitrous oxide was used from
the start of the anaesthetic, prior to
placement of the gas bubble, it will diffuse out
of the bubble on completion of the
anaesthetic, and the bubble will shrink and
risk re-detachment

57. Intraocular gas expansion
Prevention:
 discontinue nitrous 15-20 mins prior to
injection.
 Avoid nitrous oxide 5 days after air and 10
days after sulfur hexachloride injection.
 In case of perfluoropropane avoid nitrous
for atleast a month, or until the bubble is
resorbed.

58. GENERAL ANESTHESIA
MONITORING & MAINTENANCE
 Eye surgery necessitates positioning the
anesthesiologist away from the patient’s
airway, making pulse oximetry mandatory
for all ophthalmologic procedures.
 Continuous monitoring for breathing-circuit
disconnections or unintentional extubation is
also crucial.
 The possibility of kinking and obstruction of
the endotracheal tube can be minimised by
using a reinforced or preformed right-angle
endotracheal tube.

59. GENERAL ANESTHESIA
MONITORING & MAINTENANCE
 The possibility of dysrhythmias caused by
the oculocardiac reflex increases the
importance of constantly scrutinizing the
electrocardiograph.
 most pediatric surgery, infant body
temperature often rises during ophthalmic
surgen’ because of head- to-toe draping
and insignificant body-surface exposure.
 End-tidal CO2 analysis helps differentiate
this from malignant hyperthermia.

60. GENERAL ANESTHESIA
EXTUBATION & EMERGENCE
 A smooth emergence from general
anesthesia
 Deep level of anesthesia.
 Intravenous lidocaine (1.5 mg/kg) prior to
extubation.
 Severe postoperative pain is unusual.

61. COMPLICATIONS

62. COMPLICATIONS OF
REGIONAL ANAESTHESIA
 Retrobulbar hemorrhage
 Stimulation of OC reflex
 Puncture of posterior globe
 IV injection of LA
 brainstem anesthesia - (delayed onset
LOC and resp. depression)
 Optic nerve trauma.

63. RETROBULBAR
HAEMORRHAGE
 Venous hemorrhages - spread slower
 Arterial hemorrhages - rapid and taut
orbital swelling with marked proptosis.
 incidence-1% to 3%.
 Clinical suspicion: stained conjunctiva
and a proptotic globe

64. RETROBULBAR
HAEMORRHAGE
MANAGEMENT
 Determine IOP
 Ophthalmoscopy
TREATMENT
 reduce orbital compartment pressure,
thereby IOP
 Osmotic diuretics
 Lateral canthotomy
 Orbital decompression

65. OCULOCARDIAC REFLEX
The Oculocardiac Reflex(OCR) is manifested
by
 Bradycardia
 Bigeminy
 Ectopics
 Nodal rhythm
 Atrioventricular block
 Cardiac arrest

66. OCULOCARDIAC REFLEX
Caused By:
 Traction on the extraocular muscles
(medial rectus)
 Ocular manipulation
 Manual pressure on the globe
The OCR is seen during:
 Eye muscle surgery
 Detached retina repair
 Enucleation

67. OCULOCARDIAC REFLEX
 Factors contributing to the incidence of
the oculocardiac reflex:
Preoperative anxiety
Hypoxia
Hypercarbia
Increased vagal tone owing to age

68. OCULOCARDIAC REFLEX
Management
 stop stimulation by the surgeon before the
arrhythmia progresses to sinus arrest
 Atropine (0.01 mg/kg IV)
 local injection of lidocaine near the eye
muscle
Ensure
 depth of general anesthesia
 normocapnia
 surgical manipulation is gentle.

69. OCULORESPIRATORY REFLEX
 may cause shallow breathing, reduced
respiratory rate and even full respiratory
arrest.
 Trigemino vagal reflex- connection exists
between the trigeminal sensory nucleus
and the pneumotactic centre in the pons
and medullary respiratory centre.
 Commonly seen in strabismus surgery
 Atropine has no effect.

70. OCULOEMETIC REFLEX
 It is likely responsible for the high incidence
of vomiting after squint surgery (60-90%).
 Trigemino-vagal reflex with traction on the
extraocular muscles stimulating the
afferent arc.
 Antiemetics may reduce the incidence, a
regional block technique provides the best
prophylaxis

71. BRAINSTEM ANAESTHESIA
 Amaurosis
 Gaze Palsy
(Ductional Defects),
 Apnea
 Shivering
 Tachycardia and
Hypertension
 Dysphagia
 Loss Of
Consciousness
 Cardiac Arrest

72. BRAINSTEM ANAESTHESIA
 The onset of symptoms -delayed 2 to 40
minutes after injection.
Management:
 Early and prompt treatment
 100% oxygen
 maintenance of vital signs
 tracheal intubation and controlled
ventilation

73. OCULAR PENETRATION AND
PERFORATION
 most common in the myopic, elongated
globes.
 Myopics with staphyloma.
 associated with the use of large, dull
needles.
 a sensation of "poking through ”during the
placement of the needle.
 sudden appearance of hypotony, vitreous
hemorrhage or a diminished red reflex

74. OCULAR PENETRATION AND
PERFORATION
 Diagnosis -Indirect fundoscopy
 The most common sequelae- Retinal
detachment
 Appropriate retinal surgery-to prevent
the loss of vision.

75. FACIAL NERVE BLOCK
COMPLICATIONS
 Blocked at several points after exiting from the
base of the skull from the stylomastoid foramen
 Nadbath block, O'Brien procedure, Atkinson
procedure
 Disturbances of swallowing and respiratory
difficulties
 Horner's syndrome
 permanent facial nerve paralysis-longer
needles and hyaluronidase
 use of a single injection of a large volume of LA

76. COMPLICATIONS ASSOCIATED
WITH GENERAL ANAESTHESIA
 PONV
 Increase in IOP-extrusion of
intraocular contents
 Intraocular gas expansion
 Pulmonary embolism

77. POST OPERATIVE NAUSEA
AND VOMITING
 Most common complication associated
with outpatiet
 The incidence in patients undergoing
strabismus surgery -85%.
MANAGEMENT
 Metoclopromide i.v (10 mg)
 5HT3 antagonists
 Dexamethasone i.v

78. Pulmonary Embolus
 chief cause of postoperative ophthalmic
surgery death
 particularly a problem with long
procedures (retinal and oculoplastic
surgery) in the elderly.
 from a leg deep venous thrombosis
 Pneumatic leg compression devices

79. INTRAOCULAR GAS
EXPANSION
 Intravitreal air/SF6 injection: to flatten a
detached retina and allow anatomically
correct healing
 Nitrous oxide:expansion of air bubble and
rise in IOP
 Prevention: discontinue nitrous 15-20 mins
prior to injection

80. CONTROL OF INTRAOCULAR
PRESSURE
 Management of anesthesia for ophthalmic
surgery requires control of IOP before, during,
and after the procedure
 Any anesthetic event that alters the following
parameters can affect intraocular pressure
laryngoscopy
Intubation
airway obstruction
Coughing
Trendelenburg position

81. Strategies to Prevent Increases
in Intraocular Pressure
Avoid direct pressure on the globe
 Patch eye with Fox shield
 No retrobulbar or peribulbar injections
Avoid increases in central venous pressure
 Prevent coughing during induction and intubation
 deep level of anesthesia and relaxation
 Avoid head-down positions
 Extubate deeply asleep
Avoid pharmacological agents that increase IOP
 Succinylcholine
 Ketamine (?)

82. Specific Clinical Situations
and Complications

83. Penetrating Eye Injuries
 Balancing the need to prevent aspiration
of gastric contents…
 and prevention of sudden significant
increases in IOP.

84. Penetrating Eye Injuries
Strategies to Prevent Increases in Intraocular
Pressure (IOP).
 Avoid direct pressure on the globe
 No retrobulbar or peribulbar injections
 Careful face mask technique
 Prevent coughing during induction and
intubation
 Avoid head-down positions
 Avoid pharmacological agents that
increase IOP - Succinylcholine, Ketamine
(?)

85. PENETRATING EYE INJURIES
Strategies to Prevent Aspiration Pneumonia.
 Premedication by Metoclopramide and Histamine H2-
receptor antagonists
 Nonparticulate antacids
 Evacuation of gastric contents by Nasogastric tube1
 Rapid-sequence induction
 Cricoid pressure
 A rapid-acting induction agent like
Succinylcholine,1rocuronium
 Avoidance of positive-pressure ventilation
 Intubation as soon as possible
 Extubation awake

86. Pediatric Eye Injuries
 Regional eye anesthesia- not suitable
 Topical anesthetic cream:to start an
intravenous line OR
 Rapid, gentle induction of anesthesia by
mask (with 7% to 8% sevoflurane).

87. Pediatric Eye Injuries
 stomach decompression-during surgery
 To facilitate tolerance of the
endotracheal tube and minimize
bucking
1.narcotic: 10 to 20 minutes before the
end of surgery
2.lidocaine (1.5 mg/kg) 5 minutes before
extubation

88. Syringing and probing of
nasolacrimal ducts
Anaesthetic considerations:
 The surgical team may require placement of a topical
vasoconstrictor onto the child’s nasal mucosa.
 Hypotensive anaesthesia may be required to reduce
bleeding.
 The airway should be protected from blood, ideally with a
throat pack, and the nasopharynx should be adequately
suctioned out before extubation.
 Opioids may be required for analgesia for this procedure.
 The use of antimicrobial prophylaxis for those at risk of
infective endocarditis is no longer routinely
recommended for this procedure

89. STRABISMUS SURGERY
Problem
 the possible increased risk of malignant
hyperthermia
 the high incidence (PONV)
 the likelihood of an OCR
Solution
 avoid succinylcholine and halothane
 i.v lidocaine (1.5 mg/kg)
 low-dose ondansetron (50 µg/kg)
 dexamethasone (150 µg/kg) regimen

90. STRABISMUS SURGERY
 Induction technique, method of airway control
and choice of ventilation according to the
preference of the anaesthetist.
 Maintenance of anaesthesia is usually
achieved with a volatile anaesthetic agent
and air;
 The use of total intravenous anaesthesia (TIVA)
has been shown to reduce PONV.
 Consider atropine 20mcg/kg IV or
glycopyrolate 10mcg/kg IV as high incidence
of oculocardiac reflex.

91. STRABISMUS SURGERY
 PONV is common postoperatively, up to 50
– 75%.
 Giving two anti-emetic agents such as
ondansetron 0.1 mg/kg IV and
dexamethasone 0.1-0.2 mg/kg IV can
reduce this to 10%.
 Ideally extubate in deep plane.
 Analgesia should include topical tetracaine
or oxybuprocaine, NSAIDS such as
ibuprofen or diclofenac and paracetamol,
unless contraindicated.

92. STRABISMUS SURGERY
 Intraoperative opioids should be avoided due
to the high incidence of PONV, but where
necessary, consider the use of fentanyl.
 A peribulbar block is effective for analgesic
requirements and reduces PONV, possibly by
blocking the ophthalmic division of the
trigeminal nerve that passes to the vomiting
centre in the medulla.
 A sub-Tenon block performed intraoperatively
by the surgeon can be very effective for
analgesia.

93. VITREORETINAL SURGERY
 Avoid nitrous oxide if an intraocular gas
bubble is used.
 Avoid nitrous oxide in patients who have
had an intraocular bubble placed for
several weeks after the procedure.
 Controlled ventilation and paralysis should
be considered for maintaining a still eye
and avoiding raised IOP during the
procedure.

94. VITREORETINAL SURGERY
 This procedure is painful and analgesia
including opioids should be considered.
 Anti-emesis should be used routinely
 Avoid raised IOP during extubation –
extubate deep.

95. CONCLUSION
 Anesthesia for eye surgery posses unique
challenges.
 Knowledge of ocular anatomy is important to
prevent retrobulbar hemorrhage and other
complications.
 With intraocular procedures, profound
akinesia and meticulous control of IOP are
requisite.
 However, with extraocular surgery, the
significance of IOP fades, whereas concern
about elicitation of the oculocardiac reflex
assumes prominence.

96. CONCLUSION
 Intraocular pressure are affected by
physiological factors, anaesthetic drugs and
technique. The regulation of IOP is important
as increase in it can cause extrusion of the
vitreous humor and loss of vision.
 Ophthalmic drugs may significantly alter the
patient’s reaction to anesthesia.
 Regardless of the technique, ventilation and
oxygenation must be monitored, and
equipment to provide positive pressure
ventilation must be immediately available .

97. CONCLUSION
 Goal of general anaesthesia is to provide:
Smooth intubation, Stable IOP, Avoidance
of severe oculocardiac reflexes, A
motionless field and Smooth emergence
 The complications of ophthalmic
anesthesia are rare and can be both vision-
and life-threatening.
 Complications involving the intraocular
expansion of gas bubbles can be avoided
by discontinuing nitrous oxide at least 15
min prior to the injection of air or SF6, or by
avoiding the use of nitrous oxide entirely .