Airway

Question 1

Airway – Manage aspiration with LMA

[18A07] A 60-year-old man is anaesthetised for a rigid cystoscopy.

You notice bile stained fluid in his classic laryngeal mask airway (LMA) during the procedure.

Describe your management.

Answer 1

1. Severity
2. Appr Obs
3. Appr Rx

NAP4
N3Ai4Aw5An6

50% death ~ aspiration
Chemical pneumonitis
Aspiration pneumonia

Cause
1. Pt
- gastric content/delay emptying
- DM, preg, pain, opioid
- Oes dysmo
- -scleroderma
- LOS incom
- - HH, GORD, MO

Mx
1. Stable
- cric, sux 1/kg, RSI, ETT
- suction ETT
- vent 100%
2. Unstable
- O2 +++
- BMV/ETT with 100% O2

After AW secure:
- bronchospasm
- CXR
- bronch
- abandon sx
- NGT
- Once stable, plan ext
- - asym for 2 hrs = good
- sym + CXR = bad –> ICU, supp O2

Question 2

Airway - preoxygenation

[15A15] Describe the physiological principles underlying preoxygenation prior to the induction of anaesthesia (50%).

Discuss the advantages and disadvantages of using a high inspired oxygen concentration (>80%) during maintenance of anaesthesia (50%)

Answer 2

Preoxy
FRC –> O2 –> safe apnoea time
O2 consump = 250mL/min
Additional technique
- HFNP = entrain O2
- head up = inc FRC
- CPAP/PSV

Hi O2 during maintenance
PROS
1. maintain O2 in FRC

CONS
1. Atelectasis - high FiO2 –> post op absorption atelectasis
2. O2 tox
3. inc risk of AW fire (laser)
4. Delayed recog of issue (endobronch intub)

Question 3

Airway – equipment for difficult airway

[15A11]
List the essential equipment currently recommended to management a difficult airway in an adult patient (50%).

Justify supplementary items you would recommend (50%).

Answer 3

*PS55 min facility + PS56 equip to mx DA

PS56
1. Vent device
- OPA NPA
- SIB
- FM
2. SG device
- LMAs - proseal/classic
- iLMA - fastrach
3. Intub devices
-

Question 4

Which PS?

[15A11]

List the essential equipment currently recommended to management a difficult airway in an adult patient (50%).

Justify supplementary items you would recommend (50%).

Answer 4

PS56 - GL on equip to mx diff AW

PS55 - recomm min fac

A) Essential - PS56
1. VENT device
a) OPA 3-6, NPA 6-8
b) Self-infl bag
c) FMs

3. 2. SGA
      a) LMAs 3-5 proseal/classic
      b) iLMA - fastrach
4. Intubation
   a) handles
   b) blades
   c) introducer/bougie
   d) ETT
   e) ETT cuff syringe
   f) VL, special blade, AWEC, special ETT
   flexibroch 2.2mm scope fit 3.0mm ETT

+ Surgical AW - crico
+ Confirm intub –> CO2 det/capno; oseophageal intubation detector

B) Supplementary
- FIBREOPTIC
- suga
- comittube
- retrograde
- rigid bronch

Question 5

Describe the indications for and method of managing the airway during maxilla-facial surgery with a nasal endotracheal tube

Indications / CI rel/con / method /

Answer 5

Ind
1. Dental
2. Intra-oral - mandib
3. Oropharyngeal
4. AFOI with c spine
5. Intraoral mass
6. Limited MO
7. Angiooedema tongue

Abs CI:
1. Mid face instab
2. Coag
3. Susp BOS # / epiglottitis

GC notes

Question 6

STRIVE HI

Answer 6

The STRIVE Hi (SponTaneous Respiration using IntraVEnous anaesthesia and High-flow nasal oxygen) technique is an open-airway approach for endoscopic airway surgery, prioritizing spontaneous breathing while maintaining oxygenation and surgical access. Here’s a concise breakdown:

Key Steps
1. Induction Phase
- Administer propofol via target-controlled infusion (TCI) using a Cp-Ce=1 staircase titration (plasma-to-effect-site concentration differential) to achieve deep anesthesia while preserving spontaneous respiration[4].
- Alternative: Use a manual propofol infusion (e.g., start at 200 mcg/kg/min, increase by 50 mcg/kg/min every 2.5 minutes)[4].
- Apply high-flow nasal oxygen (HFNO) at 70 L/min[4].

2. Airway Preparation
   
   • Perform direct laryngoscopy (DL) at propofol Ce 5 mcg/ml and suspension laryngoscopy (SL) at Ce 6 mcg/ml[4].
   • Apply topical local anesthetic (e.g., lignocaine + phenylephrine spray) to the larynx and trachea[4].
3. Maintenance Phase
   
   • Continue propofol infusion (TCI or manual).
   • Add low-dose remifentanil (0.05 mcg/kg/min) for reflex suppression during procedures like laser surgery[4].
4. Oxygen Management
   
   • Reduce FiO₂ to <0.3 during laser use to mitigate fire risk[4].

Mnemonic: STRIVE
- Spontaneous Respiration
- Titrated Propofol (TCI/manual)
- Remifentanil (as needed)
- Intravenous anesthesia
- Ventilation via HFNO (70 L/min)
- Emergency backup plans

Expert Insights
- HFNO Benefits: Maintains oxygenation even in obesity, emphysema, or pregnancy[4].
- Laser Safety: Use FiO₂ <0.3 and avoid combustible materials[4].
- Troubleshooting:
- Airway reactivity: Increase anesthesia depth, add remifentanil, or reapply local anesthetic[4].
- Apnea: Reduce propofol/remifentanil; escalate to supraglottic intubation or tracheostomy if unresolved[4].
- Complete obstruction: Use airway adjuvants (e.g., nasopharyngeal airway) or surgical rescue[4].

This approach balances surgical access with respiratory safety, particularly in high-risk airways[4].

Citations:
[1] https://academic.oup.com/bja/article/118/3/444/2999638
[2] https://www.shanahq.com/main/sites/default/files/STRIVE_Hi_approach_endoscopic_airway%20surgery.pdf.
[3] https://academic.oup.com/bja/article/118/3/444/2999638
[4] https://www.shanahq.com/main/sites/default/files/STRIVE_Hi_approach_endoscopic_airway%20surgery.pdf

Answer from Perplexity: pplx.ai/share