‘Mechanical Ventilation Modes’ seeks to shed light on this hotly debated topic, one that is complicated by ventilator manufacturers’ non-standardized terminology. The chapter looks at conventional modes, adaptive modes, and biphasic modes, which it classifies based on the mechanical breath types in each mode. It includes a comparison chart of the terminology used for common modes on popular IPPV ventilators. Using their signature waveforms, the author describes the assist/control, SIMV, and pressure support ventilation or PSV modes. It defines the modes by their application of spontaneous breaths and mandatory breaths. It continues with a discussion of adaptive modes and biphasic modes. It ends by discussing how to select the appropriate ventilation mode.