01Risk Stratification
Airway risk factors: - Known difficult airway - Airway deterioration (bleeding, edema, trauma, prone/Trendelenburg, large-volume resuscitation) - Restricted airway access - Obesity, OSA - Aspiration risk
General risk factors: - Cardiovascular, respiratory, neuromuscular disease - Metabolic derangements - Special surgical requirements (e.g. neck immobility post-fusion)
DAS Guidelines (2012): - Low risk: awake vs deep extubation - High risk: awake + advanced strategies (airway exchange catheter, LMA exchange, remifentanil technique) vs postpone vs tracheostomy
02Routine Extubation Criteria
- Vital signs stable
- - BP/HR within acceptable range on minimal pressors
- - Temperature > 35.5 °C
- - Spontaneous RR 6–30, SpO₂ > 90%
- Reasonable ABG with FiO₂ ≤ 40%
- - pH ≥ 7.30, PaO₂ ≥ 60 mmHg, PaCO₂ ≤ 50–60, normal lytes
- - EtCO₂ < 60 as surrogate
- Adequate NMB reversal
- - TOF 4/4, ratio > 0.7–0.9, tetany > 5 s
- - Direct palpation cannot determine ratio > 0.9
- - Sustained head lift / hand grasp > 5 s (sensitive but not specific)
- Respiratory mechanics adequate
- - Spontaneous TV > 5 mL/kg, VC > 15 mL/kg
- Protective reflexes (gag, swallow, cough) returned*
- Awake, alert, follows commands*
- Optimize: 100% O₂, slight reverse Trendelenberg, suction oropharynx, ± IV lidocaine to reduce coughing
Not required for deep extubation.
03Deep Extubation
Pros: ↓ tachycardia, HTN, coughing → ↓ wound dehiscence, bleeding, bronchospasm.
Cons: Risk of laryngospasm during emergence in transport or PACU.
Criteria: adequate depth — no response to pharyngeal suction or jaw thrust, no breath-holding.
Avoid in: difficult airway, full stomach / aspiration risk, OSA.
04Causes of Failed Extubation
| Cause | Pre-extubation checklist |
|---|---|
| Failure to oxygenate | TV > 5 mL/kg & VC > 15 mL/kg; SpO₂ > 90% on FiO₂ < 0.4 |
| Failure to ventilate | Same TV; reversed NMB; RR 6–30; EtCO₂ < 50–60 |
| Poor secretion clearance | Oropharynx suctioned; gag intact; cough; awake; lateral decubitus if aspiration risk |
| Loss of airway patency | Bite block; alert; cuff leak > 10–15% if edema concern; sniffing/head-up; reduced laryngospasm risk; AEC if high-risk |
05Cuff Leak Test
- On volume-control mode, deflate ETT cuff
- In absence of significant edema, you should hear/see a leak
- Calculate leak = programmed TV − observed expiratory TV
- Leak < 10–15% of TV → significant airway edema → defer extubation or use AEC + steroid pretreatment
06Delayed Emergence — DDx
Residual drugs: opioids, benzodiazepines, NMBA (always recheck TOF), volatile (especially if FiO₂ low / low FGF), reversal incomplete.
Metabolic / electrolyte: - Hypoglycemia (esp. peds, diabetics, liver failure) - Hyperglycemia (HHS, DKA) - Hyponatremia (TURP syndrome) - Hypothyroid / hypoadrenal - Hypothermia - Hypoxemia, hypercarbia
Neurologic: - Stroke (esp. cardiac/carotid surgery) - Intracranial hemorrhage - Seizure with prolonged postictal state - Central anticholinergic syndrome (atropine, scopolamine) — treat with physostigmine
Workup: check TOF, ABG, glucose, lytes, temperature; consider reversal trials (naloxone, flumazenil); if persistent → neuro exam, CT head.