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Critical Care / ICU · Ward Pathways · Locked — free with a referral
By Dr Javed Akhtar · Last reviewed 2 October 2026
Presentation Exhausted, SpO₂ 82% on 15 L, PaCO₂ 68 mmHg and climbing — type I vs type II failure, NIV or tube, and the first safe ventilator settings.
Red flags Silent chest or rising PaCO₂ in asthma GCS falling with hypoxia Post-intubation hypotension (auto-PEEP, tension PTX, sedation) Tube at 18 cm in a tall adult (too high) — 21–23 cm typical Differential diagnosis COPD/asthma exacerbation Pneumonia, pulmonary oedema Pneumothorax Metabolic acidosis with respiratory compensation (DKA, sepsis) When to admit, call ICU or discharge Intubate: GCS <8, exhaustion, refractory hypoxia, or failing pH despite NIVVT: 6–8 mL/kg predicted (not actual) body weightPlateau: Keep <30 cmH₂O; driving pressure <15Key points Predicted body weight: men = 50 + 2.3 kg per inch over 5 ft; women = 45.5 + 2.3 Post-intubation hypotension is common — preload, pressors ready, and check for auto-PEEP ETCO₂ confirms the tube; a normal SpO₂ does not exclude oesophageal intubation Never Ventilate to a 'normal' PaCO₂ in a chronic CO₂ retainer — aim for their baseline pH Use actual body weight for tidal volume Give a long-acting paralytic then struggle to assess neurology Common mistakes Bagging too fast pre-intubation → gastric insufflation High tidal volumes 'to improve the ABG' Sedating without analgesia Missing oesophageal intubation because SpO₂ lagged Disposition and follow-up ICU for all ventilated patients; daily SAT/SBT paired trials; tracheostomy if ventilated >7–10 days anticipated.
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