ⓘEducational use only — not medical advice. This is a teaching example and must not be used to guide care of any individual patient.Learn more →
Late Cycle in APV
The late inspiratory pressure peak of late cycling is shown.
APVLate cycleM2M5
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Fig 1.Late cycling happens when the cycle variable, the variable that controls the duration of inspiration, is set longer than the duration of patient’s inspiratory effort. Looking at the pressure versus time waveform, we can see that, through most of inspiration, airway pressures are relatively low and rise at its very end. This late peak, classic of late cycling, may happen for two reasons. First, it may be secondary to the relaxation of inspiratory muscles, which were previously expanding the chest and lowering airway pressures. Second, occasionally, the contraction of expiratory muscles may raise airway pressures. Treatment of this dyssynchrony involves shortening inspiratory time by manipulating the cycle variable (on APV, one would lower iTime).
