Hypoxia during OLV is common: optimise FiO2, ventilation, and perfusion (PEEP, position, CPAP to operative lung if needed). Confirm tube position with fibreoptic bronchoscope.
Indications
- Thoracic surgery (lobectomy, VATS)
- Lung isolation for haemoptysis or infection (selected)
- DLT or bronchial blocker depending on case
Setup checks
- Correct side DLT (left default for most)
- FOB after positioning for tracheal and bronchial cuffs
- Clamp correct lumen after test ventilation
Stable OLV
- Saturations maintained, tube confirmed
- Lung-protective settings
- Position checked with FOB
Desaturation
- FiO2 1.0, recruit dependent lung
- PEEP 5 to 10, ensure cardiac output
- Recheck tube and clamp side
Refractory hypoxia
- CPAP to the operative lung
- Intermittent two-lung ventilation
- Pause surgery or abort if unsafe
Hypoxia on OLV
1
1. Confirm
Tube position, clamp on correct side, no circuit leak.
Tube position, clamp on correct side, no circuit leak.
↓
2
2. Optimize
FiO2 1.0, recruit dependent lung, PEEP 5 to 10 cmH2O, ensure adequate CO.
FiO2 1.0, recruit dependent lung, PEEP 5 to 10 cmH2O, ensure adequate CO.
↓
3
3. CPAP
Low CPAP (1 to 5 cmH2O) to non-dependent (operative) lung if tolerated surgically.
Low CPAP (1 to 5 cmH2O) to non-dependent (operative) lung if tolerated surgically.
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4
4. Last resort
Intermittent two-lung ventilation, clamp release with surgeon, or abort if unsafe.
Intermittent two-lung ventilation, clamp release with surgeon, or abort if unsafe.
DLT sizes (guide)
- Choose by height and airway; have alternate size
- Right DLT needs care with upper lobe ventilation
Pitfalls
- Wrong-sided clamp
- No FOB after patient turn
- Ignoring shunt from atelectasis
MedPrep - www.medprep.uk - Educational revision aid only. Not clinical guidance. Doses are adult examples; check the BNF, current guidelines and local policy, and seek senior advice. Nov 2026