ENT And Ophthalmology

Question 1

Name picture 62

Answer 1

South facing preformed et tube

Question 2

Name picture 63

Answer 2

North facing preformed et tube

Question 3

Name picture 64

Answer 3

North facing preformed et tube

Question 4

Name picture 65

Answer 4

South facing preformed et tube or right angled ETT

Question 5

Name picture 66

Answer 5

Endotracheal tube for laser surgery: 2 bulbs ( 1 with water to prevent burn injury and reduce risk explosion)

Question 6

What type of airway is seldom used in ENT surgery?

Answer 6

Jet insufflators for ventilation

Question 7

What 3 type of airway is commonly used in ENT surgery?

Answer 7

• Preformed south facing ETT = tonsillectomy
• preformed north facing ETT
• laser compatible ETT

Question 8

Which anaesthetic agent should be avoided in ear surgery and why?

Answer 8

Nitrous oxide
Expand gas filled spaces so will disrupt suture lines

Question 9

How can an airway fire be prevented in ENT surgery when lasers are used? ( 5)

Answer 9

• low fio2
• saline soaked plegets
• intensity and duration of laser
. ETT bulb saline filled
• airway device resistance to laser

Question 10

What type of airway should be used for tonsillectomies and adenoidectomies?

Answer 10

Oral RAE tube ( south facing) and throat pack to catch soiling at back of throat

Question 11

Name 3 relatively common complications or occurrences during eye surgery under anaesthesia

Answer 11

• Extubation of patient
• bradycardia
• overheating

Question 12

Name 4 cardiac and respiratory variables that increase intraocular pressure

Answer 12

• Increased CvP increase severely!
• increase arterial blood pressure
• increased paco2 (hypoventilation)
• decrease pa02

Question 13

What is the oculo-cardiac reflex? Name 4 causes and presentation

Answer 13

Cardiac arrhythmia (usually Brady) due to:
• traction on ocular muscles
• pressure on eyeball
• admin retrobulbar block
• trauma to eye

Presentation ranges: bradycardia, ventricular ectopy, sinus arrest, v fib.

Question 14

Pathophysiology of oculo-cardiac reflex?

Answer 14

• trigeminal V1 afferent
• vagal efferent

Question 15

Risk group for oculocardiac reflex?

Answer 15

Most commonly Paeds strabismus surgery

Question 16

Management oculocardiac reflex? (4)

Answer 16

• Notify surgeon so they can cease surgical stimulation until heart rate increase
• confirm adequate ventilation, oxygenation, depth of anaesthesia
• administer atropine! 10 micrograms/kg
• infiltrate rectus muscle with local anaesthesia if persist

Question 17

Name 4 ophthalmic drugs with systemic side effects

Answer 17

• Topical phenylephrine: hypertension, bradycardia
• echothiopate: prolong succinylcholine duration (irreversible cholinesterase inhibitor)
• epinephrine adrenaline eye drops: sympathomimetic side effects and arrhthmogenic
• timolol: atropine resistant bradycardia, hypotension, bronchospasm (beta blocker)

Question 18

How perform retrobulbar blockade? (4)

Answer 18

• Inject 2,5 ml ligno/bupiva/ropiva (add hyaluronidase to encourage spread) into cone formed by extra-ocular muscles
• patient look supranasally
• needle advanced 1,5 cm along inferotemporal wall
• needle directed upward and nasally toward apex orbit

Question 19

Name 5 complications retrobulbar blockade?

Answer 19

• Haemorrhage especially retrobulbar (affect optic nerve and intraocular pressure)
. Perforation globe
• intravascular injection
• potent inducer oculocardiac reflex
• respiratory arrest
• acute neurogenic pulmonary oedema

Question 20

How perform peribulbar blockade? (6)

Answer 20

• Patient look straight ahead
• 2 trans conjunctival injections given
• inferotemporal-halfway between lateral canthus and lateral limbus
• needle advance under globe parallel to orbital floor
• directed medial and cephalad
• 5 ml injection of ligno and bupivacaine

Less risk damage to globe and surrounding structures compared to retrobulbar but not as good of a block

Question 21

Best method of induction and airway establishment in patient with large neck mass for exploration?

Answer 21

Mask inhalation induction

Question 22

Which agent must be avoided in ear surgery

Answer 22

Nitrous oxide

Question 23

Name 2 agents that increase intraocular pressure so should be avoided in eye surgery

Answer 23

• Ketamine
• succinylcholine