This guide integrates essential standards for gas supply, circuits, airway management, and protective ventilation strategies.
1. Gas Supply, Safety, and Vaporizers
Pin Index Safety System (PISS) prevents the connection of the wrong gas cylinders.
| Gas | Colour (Int’l) | Pin Index |
|---|---|---|
| Oxygen | White / Green | 2, 5 |
| Nitrous Oxide | Blue | 3, 5 |
| Air | Grey / White | 1, 5 |
Vaporizer Colour Coding:
- Isoflurane (Purple),
- Sevoflurane (Yellow),
- Desflurane (Blue).
2. Breathing Circuits & Airway Management
- Mapleson Circuits: Classified by FGF, bag, and APL valve arrangement. Mapleson D (Bain circuit) is the most common clinical coaxial system.
- ETT Types: PVC (standard), Reinforced (wire-coiled, avoids kinking), Laser-resistant (for airway surgery), and Double-lumen (independent lung ventilation).
- LMA: Supraglottic device, fundamental for both routine use and “cannot intubate, cannot oxygenate” (CICO) rescue algorithms.
- ASA Difficult Airway Protocol: Emphasizes preparation: Videolaryngoscopy, Bougie, Fiberoptic scope, and predefined rescue plans.
3. Ventilation Modes
| Mode | Technical Description |
|---|---|
| VCV | Volume Control: Delivers a fixed tidal volume at a set rate. |
| PCV | Pressure Control: Delivers flow to a set inspiratory pressure. |
| SIMV | Synchronized Intermittent Mandatory Ventilation: Combines machine breaths with patient-triggered breaths. |
| PSV | Pressure Support: Entirely patient-triggered; assists each spontaneous breath. |
Critical Care Note: Lung-Protective Strategy
To prevent VILI (Ventilator-Induced Lung Injury), utilize:
- Low Tidal Volume: 6 ml/kg (Predicted Body Weight).
- PEEP Optimization: To maintain alveolar recruitment without over-distension.
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