The respiratory therapist is called to a patient's room because the "alarms are ringing." When the respiratory therapist arrives at the bedside, the high pressure limit, low exhaled tidal volume, and low exhaled minute volume alarms are active

Question

The cause of these alarms is which of the following?
a. Disconnection from the ventilator.
b. Critical leak in the ventilator circuit.
c. Lung compliance has improved.
d. Airway resistance has increased.

Answer 1

ANS: D
The low exhaled tidal volume and minute volume alarms are active when the high pressure limit alarm is active. This occurs because reaching the set high pressure limit setting will end inspiration immediately by pressure cycling and thereby will decrease the volume delivered to the patient. When the high pressure limit alarm is active for several breaths, the low exhaled tidal volume and then the minute ventilation alarms will become active. The high pressure alarm will sound when airway resistance is elevated (e.g., asthma). A disconnect from the ventilator or a critical leak would cause the low peak inspiratory pressure alarms to ring. Improved lung compliance will lower the peak inspiratory pressure and may trigger a low pressure alarm.