As the therapist works with a mechanically ventilated patient, he notices that the ventilator is auto-triggering. What should the therapist do to eliminate this problem? I. Add water to the heated humidifier. II. Check the patient-ventilator system for leaks. III. Scrutinize the breathing circuit for the accumulation of condensate. IV. Ensure that the high-pressure alarm is appropriately set

A. I, II only
B. II, III only
C. I, III, IV only
D, I, II, IV only

?ANS: B
A. Incorrect response: See explanation B.
B. Correct response: Auto-triggering occurs when the triggering system of the ventilator is overly sensitive. Factors that can cause auto-triggering include condensate in the ventilator breathing circuit and a leak in the patient-ventilator system.
Respiratory system depression associated with a low respiratory rate is susceptible to auto-triggering. This condition prevents flow for a certain period. Zero flow through the system for an extended time makes the system vulnerable to triggering from changes in the airway pressure occurring within the ventilator breathing circuit. These vulnerabilities are not related to patient effort;, rather they pertain to pressure changes within the circuit, even an event as subtle as cardiogenic oscillations.
C. Incorrect response: See explanation B.
D. Incorrect response: See explanation B.