Author
Burton W. Lee, MD
Pulmonary Critical Care Section
Medstar Washington Hospital Center
Associate Professor of Medicine
Georgetown University School of Medicine
Case
Consider a patient with massive intracerebral hemorrhage on volume cycled AC mode as follows: 30% FIO2 / Vt 0.5 L / rate 12 / PEEP 5 / flow 55 lpm decelerating pattern / flow triggering 2 lpm. Patient has fixed dilated pupils, exhibits no brainstem reflexes and is unresponsive to all stimuli. However, it appears she is breathing at a rate of 20 when the set ventilator rate is 12. Therefore an apnea test is being deferred. Below are the pressure-time (top) and flow-time (bottom) curves for the patient.
Question
What is happening to this patient?
A. Delayed Expiratory Cycling - Prolonged inspiration due to an inappropriately low inspiratory flow setting.
B. Inspiratory Flow Starvation.
C. Ineffective Triggering
D. Autotriggering