AS11.5-6 | Advanced Airway Indications and Mechanical Ventilation Settings — Summary & Reflection

KEY TAKEAWAYS

Advanced airway management is indicated when basic manoeuvres fail due to: inability to oxygenate (SpO₂ <90% despite NRM), inability to ventilate (progressive hypercapnia with acidosis), failed airway protection (GCS ≤8, absent reflexes), or anticipated deterioration. Endotracheal intubation requires three-axis alignment (sniffing position), laryngoscopy to identify the glottis, tube passage under vision, and confirmation by capnography (gold standard) plus auscultation, chest rise, and CXR. Mallampati class III/IV predicts difficult laryngoscopy; ASA class grades systemic disease, not airway difficulty — these are different scales. Mechanical ventilation controls oxygenation (via FiO₂ and PEEP) and ventilation (via VT and RR). Lung-protective settings: VT 6–8 mL/kg IBW; initial RR 12–16/min; PEEP 5 cmH₂O baseline (higher in ARDS); FiO₂ titrated to minimum maintaining SpO₂ ≥94%. Plateau pressure must be kept ≤30 cmH₂O; elevated peak with normal plateau indicates airway resistance problem; elevated both indicates compliance problem. ABG guides adjustment: high PaCO₂ → increase minute ventilation; low PaO₂ → increase FiO₂ or PEEP.

REFLECT

In your next clinical posting in the operating theatre or ICU, ask your supervising anaesthetist or intensivist to explain the ventilator settings for one patient you are observing. Before they speak, read the screen yourself and try to interpret: Is the VT appropriate for the IBW? Is the PEEP appropriate for the diagnosis? What does the plateau pressure tell you about lung compliance? Then compare your reasoning with the consultant's explanation. After the encounter, write a brief note (in your clinical logbook or journal) identifying: one thing the consultant knew that you did not, one thing you got right, and one question you want to research before your next session. This cycle of deliberate observation, prediction, and reflection is the engine of clinical learning.