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EN2.7 | ENT Surgical Instruments — SDL Guide (Part 3)
Self-Assessment: ENT Instrument Competency Check
Test your instrument knowledge against these direct identification questions. For each, attempt the full answer (name + description + surgical use + important anatomical or safety point) before reading.
Q1: An instrument described as a rigid telescope with a 30° angle of view, used in nasal endoscopy and FESS. Answer: Hopkins rod rigid nasal endoscope (30°). Used in FESS to view the middle meatus and ethmoid bulla (the 30° angle brings these into view without requiring the endoscope to be bent). Connected to a camera and monitor. 0° for the nasal cavity; 30° and 45° for the sinuses; 70° for the frontal recess.
Q2: An instrument with one blade inside the nose and one externally, used to manipulate fractured nasal bones. Answer: Walsham's forceps (or Ash's forceps). Used for closed reduction of a fractured nasal bone. The internal blade is placed along the nasal cavity lateral wall; the external blade over the displaced nasal bone fragment. Squeezing the blades together levers the fragment back into position.
Q3: A very small, curved blade on a handle, designed for making a single incision in the antero-inferior quadrant of the TM. Answer: Myringotomy knife (Beaver blade for myringotomy). The antero-inferior quadrant is the safe site — ossicles are postero-superior and the jugular bulb is postero-inferior. After myringotomy, pus or fluid is aspirated and a grommet (ventilation tube) is inserted to maintain middle ear ventilation.
| Instrument | Procedure | Key feature |
|---|---|---|
| Boyle-Davis gag | Adenotonsillectomy | Central ET tube channel; suspended from Draffin bipod |
| Trousseau dilator | Tracheostomy | Spreads tracheal incision; blunt — safe near posterior wall |
| Hopkins rod endoscope | FESS, nasal endoscopy | 0°, 30°, 45°, 70° angles available |
| Myringotomy knife | Myringotomy | Used in antero-inferior quadrant (safe site) |
| Rosen needle | Tympanoplasty | Elevates tympanomeatal flap |
| Walsham's forceps | Nasal bone reduction | One blade inside nose, one external |
| Killian speculum | Septoplasty | Long-bladed; distinguishable from short Thudichum |
| Beckmann curette | Adenoidectomy | Ring-shaped, sharp edge; avoids Eustachian tube orifice |
SELF-CHECK
The standard tracheostomy site is between which tracheal rings, and why is the first tracheal ring avoided?
A. Between 1st and 2nd rings; the 1st ring is thin and may be injured
B. Between 2nd and 3rd rings; incision at the 1st ring risks subglottic stenosis
C. Between 4th and 5th rings; higher incisions risk the thyroid gland
D. Between 2nd and 3rd rings; incision here avoids the cricothyroid membrane
Reveal Answer
Answer: B. Between 2nd and 3rd rings; incision at the 1st ring risks subglottic stenosis
The standard tracheostomy site is between the 2nd and 3rd tracheal rings. The 1st tracheal ring is avoided because an incision through or adjacent to the cricoid cartilage (which connects with the 1st ring superiorly) risks subglottic stenosis — a serious complication causing airway narrowing below the vocal cords. Going too low (below the 4th ring) risks injury to the innominate artery (brachiocephalic trunk), which can cause fatal haemorrhage. The cricothyroid membrane (between thyroid and cricoid cartilages) is used for emergency cricothyroidotomy only — not for elective tracheostomy.