Inappropriate ventilator triggering caused by an in-line suction catheter.

OBJECTIVE: To examine the phenomenon of inappropriate triggering caused by an in-line suction catheter. DESIGN: We used a test lung to assess inappropriate triggering in four ventilators with both pressure and flow triggering. RESULTS: With pressure triggering, inappropriate triggering occurred only in the presence of PEEP. However, with flow triggering, inappropriate triggering occurred both with and without PEEP. Inappropriate triggering did not occur in a model of severe airflow obstruction. CONCLUSION: In-line suction catheters may lead to inappropriate triggering and potentially dangerous increases in delivered ventilation.