Mechanical Ventilation & ARDS
Understand protective ventilation, bedside reassessment and liberation from support.
Quick revision ↓ Medical Dictionary
01Understand the ventilator
Mechanical ventilation supports gas exchange while the cause of failure is treated. Review mode, oxygen concentration, pressure, volume, rate and patient interaction. Changes should be made by trained staff with assessment of gas exchange, haemodynamics and synchrony rather than a number in isolation.
02Protect the lung
Excessive stretch and pressure can injure the lung. Lung-protective strategies use tidal volume related to predicted body weight, appropriate pressure limits and individualised PEEP. Actual body weight alone is not the basis for setting tidal volume in an obese patient.
03Recognise ARDS
ARDS involves acute inflammatory lung injury with hypoxaemia and bilateral abnormalities not fully explained by cardiac failure or fluid overload. Diagnose using an accepted current definition and clinical context. Treat the precipitating illness while applying a protective respiratory strategy.
04Respond to deterioration
A sudden alarm or desaturation requires assessment of the patient, airway, circuit and chest. Consider displacement, obstruction, pneumothorax and equipment failure. Call experienced help promptly; do not simply silence an alarm or raise settings without identifying the cause.
05Wean and rehabilitate
Review daily whether the cause is improving and whether sedation and support can safely decrease. Spontaneous breathing assessment is only part of extubation readiness: airway protection, cough and secretion burden also matter. Mobilisation and communication help recovery during prolonged support.
High-Yield Revision
- Use predicted body weight for protective tidal-volume planning.
- Assess the patient before treating an alarm as a device problem.
- Extubation needs airway protection as well as breathing ability.
Common Pitfalls
- Using actual weight alone to set tidal volume.
- Equating a breathing-trial pass with automatic safe extubation.
References & Further Reading
Read the relevant guideline sections alongside these original clinical teaching cases. Local pathways, available services and individual patient factors determine care.
Reference review: 29 September 2026. Consult current local protocols for prescribing, procedures and escalation.