ENT & Ophtho
Special Surgeries
Emergencies & Crisis Management
Pharm
100
Normal range of intraocular pressure (IOP) in mmHg?
What is 10–22 mmHg
100
Which surgical manipulation during neck dissection can cause sudden severe bradycardia, and what block prevents this?
Carotid sinus pressure → vagal bradycardia; carotid sinus local infiltration with lidocaine prevents it.
100
Immediate action for airway compromise from neck hematoma?
Open wound at bedside to evacuate hematoma.
100
Ophthalmic drug that prolongs succinylcholine effect?
Echothiophate
200
Why discontinue nitrous oxide ≥15 min before tympanic graft placement?
What is To prevent ↑ middle ear pressure disrupting graft.
200
Which electrolyte abnormality after parathyroidectomy can precipitate laryngospasm, and what is its mechanism?
Hypocalcemia → increased neuromuscular excitability (low threshold potential).
200
Describe the exact sequence for airway fire management during laser surgery, including re-establishment of ventilation.
Stop gases → remove ETT → extinguish fire (saline) → mask ventilate with air → inspect airway for damage → re-intubate once safe
200
Succinylcholine effect on IOP?
↑ IOP by ~9 mmHg for 1–4 min.
300
Cranial nerve afferent limb of oculocardiac reflex
CN V (ophthalmic division).
300
In thyroidectomy, how can ETT cuff pressure monitoring help detect a critical intraoperative nerve injury?
EMG ETT electrodes detect recurrent laryngeal nerve stimulation; sudden loss of signal may indicate nerve injury.
300
In epiglottitis, what airway approach carries highest mortality, and what is the preferred strategy?
Awake direct laryngoscopy in child; preferred: inhalational induction with spontaneous ventilation, surgeon prepared for surgical airway.
300
Two drugs to treat persistent OCR-induced bradycardia?
Atropine (0.01–0.02 mg/kg IV) or glycopyrrolate.
400
In middle ear surgery, how can nitrous oxide cause delayed postoperative vertigo, and what is the mechanism?
N₂O diffuses into closed middle ear spaces → pressure changes displace ossicular chain and labyrinth fluids → postoperative vertigo.
400
Two cranial nerves most at risk in neck dissection?
CN XI (shoulder weakness), recurrent laryngeal (vocal cord dysfunction).
400
In foreign body aspiration of the right mainstem bronchus in a child, why is muscle relaxation contraindicated before bronchoscope insertion?
Muscle relaxation and PPV can push object distally; maintain spontaneous ventilation until surgeon controls airway.
400
Which ophthalmic drug is a carbonic anhydrase inhibitor and what is its metabolic side effect?
Acetazolamide; metabolic acidosis with hypokalemia.
500
Why is PONV risk particularly high in strabismus surgery beyond OCR, and what intraoperative agents are evidence-based to reduce it?
Extraocular muscle manipulation stimulates vestibular system; prophylaxis: ondansetron, dexamethasone, propofol maintenance, scopolamine patch.
500
What are two physiologic risks of venous air embolism during neck dissection, and how can they be minimized intraoperatively?
Hypotension & hypoxemia from air entrainment; prevent by head-down positioning, maintain venous pressure, avoid open non-compressed neck veins.
500
During Endoscopic Sinus Surgery, sudden severe bradycardia and hypotension occur. What’s the likely cause and immediate management?
Likely trigeminocardiac reflex from nasal/sinus manipulation → stop stimulus, give 100% O₂, deepen anesthesia, administer anticholinergic if persistent.
500
List two systemic cardiovascular effects of topical timolol, and why these can be severe in elderly patients.
Bradycardia, bronchospasm; elderly more sensitive due to comorbid conduction disease and ↓ β-receptor reserve.