Mechanical Ventilation Basics Medical Slides

Present modes by clinical context: volume-controlled ventilation (AC-VC) for initial resuscitation — guarantees minute ventilation; pressure-controlled ventilation (AC-PC) for ARDS with high peak pressures — decelerating flow improves distribution; pressure support (PSV) for weaning — patient-triggered with flow cycling. Include APRV for refractory ARDS. Emphasize that no single mode has proven mortality benefit — operator familiarity and appropriate settings matter more than mode selection.

Present the daily awakening (SAT) plus spontaneous breathing trial (SBT) protocol from the ABC trial (Girard 2008) — combined SAT/SBT reduced ventilator days and mortality. Reference the rapid shallow breathing index (RSBI = RR/VT, threshold <105), SBT methods (T-piece vs low PSV — both acceptable per 2017 ATS/ACCP guidelines), and the A2F bundle. Include predictors of extubation failure: cough strength, secretion volume, mental status.

Teach the three fundamental waveforms with abnormal patterns: (1) pressure-time — elevated plateau pressure (>30 cmH2O) indicates reduced compliance, high peak-plateau gradient indicates increased resistance; (2) flow-time — failure to return to zero baseline indicates auto-PEEP/air trapping; (3) volume-time — failure to return to zero indicates air leak. Include trigger asynchrony (ineffective efforts seen as negative pressure deflections without triggering breath) and its correction strategies.