A patient’s WOB is minimal during mechanical ventilation
with an appropriate VT and rate. As the ventilator support is gradually discontinued
and the patient is expected to take over more of WOB, airway resistance
associated with breathing through an endotracheal tube may become clinically
important. The RT must be able to recognize this problem readily and know how
to correct it.
A patient has received mechanical ventilation in volume
controlled CMV mode for the past week. The patient’s condition is now
clinically stable, and ventilation is provided by PSV. As the PSV pressure
level is reduced to 8 cm H2O, the patient begins using accessory
muscles to breathe, the spontaneous respiratory rate increases to 30
breaths/min, and the patient reports shortness of breath. Blood gas values are
acceptable, and no abnormal lung sounds are present. What is the problem, and
what should the RT do?