The Science Journal of the American Association for Respiratory Care

2012 OPEN FORUM Abstracts


Susan Gole, Robert L. Chatburn; Respiratory Institute, Cleveland Clinic, Cleveland, OH

ICU ventilators differ drastically in operator interface design. Different designs result in different sequences of steps required to first perform a ventilator operation verification procedure (OVP) and then to enter initial ventilator settings (IVS). The purpose of this study was to define and compare the cognitive load and time investment required for these steps. Our hypothesis was that these metrics will differ among ventilator models. METHODS We evaluated 3 intensive care ventilators; Puritan Bennett 840, Servo S, and Dräger Evita XL with patient circuits attached. The cognitive load was defined as the number of steps (operator actions) from power on to “ready for patient use” for each ventilator. Set-up was divided into OVP and IVS phases. Initial ventilator settings were volume control continuous mandatory ventilation; rate 16 breaths/min, tidal volume 450 mL, FiO2 0.5, PEEP 5 cm H2O, peak flow 60 L/min or inspiratory time 0.9 s and flow trigger 3 L/min. Alarm settings: high pressure 50 cm H2O, low pressure 3 cm H2O, high tidal volume 800 mL and low minute ventilation 3 L/min. Backup ventilation settings: apnea 20 seconds and other settings as above. A single experienced operator recorded (in triplicate) the total time required for each phase of ventilator set-up. Mean values were for OVP and IVS times were compared with ANOVA. Significance was assigned for P values < 0.05. RESULTS The cognitive load was different for each ventilator: Evita XL (33 steps) PB 840 (31 steps) and Servo S (25 steps). Results for OVP and IVS times are shown in the Figure. The Servo S had the shortest total time (OVP + IVS) and the PB 840 the longest (P = 0.004). However, the difference may not be practically important. CONCLUSION Cognitive load and time required for initial set-up are comparable for these ventilators. Sponsored Research - None