Ventilator Masterclass

Delivers a set tidal volume with each breath (patient-triggered or mandatory). Every breath — whether triggered by the patient or by the machine — delivers the full set Vt. Guarantees minimum minute ventilation.

Delivers mandatory breaths at set rate synchronized to patient effort. Between mandatory breaths, patient breathes spontaneously (with or without pressure support). Mandatory breaths are volume-controlled.

Sets an inspiratory pressure limit; delivers breaths to that pressure, with tidal volume varying based on compliance and resistance. Provides a decelerating flow waveform which improves gas distribution.

Dual-control mode: targets a set Vt while using the lowest possible inspiratory pressure. The ventilator measures compliance each breath and adjusts pressure up or down to hit the target Vt with a 5 cmH2O safety margin from Pmax.

Maintains a high continuous positive airway pressure (P-high) for a long time (T-high, typically 4–6 sec), then briefly releases to a low pressure (P-low ≈ 0) for a short time (T-low, typically 0.4–0.8 sec) to allow CO2 to escape. Patient breathes spontaneously throughout at P-high.

Delivers very small tidal volumes (1–3 mL/kg) at very high frequencies (3–15 Hz) via a piston or diaphragm. Gas moves by convection, diffusion, and asymmetric velocity profiles. Mean airway pressure (MAP) controls oxygenation; amplitude (ΔP) controls CO2 removal.

Delivers high-velocity jets of gas through a small-bore injector cannula at 150–400 breaths/min. Extremely small tidal volumes. Primary use is minimizing airway pressure in pulmonary interstitial emphysema (PIE).

Applies a constant positive pressure throughout the respiratory cycle. No additional ventilatory support — patient does ALL the work. Pressure splints the upper airway open and recruits alveoli.

Applies two levels of pressure: IPAP (higher, during inspiration) and EPAP (lower, during expiration). The difference (IPAP − EPAP) provides pressure support, augmenting tidal volume. EPAP provides PEEP (oxygenation). Can have a backup rate.

Delivers heated, humidified oxygen at flows of 20–60 L/min through a specialized nasal cannula. Mechanisms: meets/exceeds inspiratory flow demand (prevents FiO2 dilution), generates ~1–2 cmH2O PEEP per 10 L/min, flushes dead space (CO2), improves mucociliary clearance.

Applies a set positive pressure during patient-triggered inspiratory effort to augment Vt. The patient triggers EVERY breath — there is no mandatory rate. Flow cycles OFF when flow decreases to 25% of peak (or patient begins to exhale). Used during weaning and as support above PEEP.