CareFusion AVEA - Imposed Work of Breathing (Wobi)

230 Appendix G: Advanced Pulmonary Mechanics Monitored Parameters Operator's manual
L2786 Rev. M
Imposed Work of Breathing (WOB
I
)
Imposed Work of Breathing (WOB
I
), is defined as the work performed by the patient to breathe
spontaneously through the breathing apparatus, i.e. the E.T. tube, the breathing circuit, and the demand
flow system.
Imposed work is assessed by integrating the change in tracheal pressure and tidal volume, and
normalizing the integrated value to the total inspiratory tidal volume (V
ti
). (Requires the use of an optional
tracheal catheter.) Based on the following formula:
WOBI =
( )
∫
−
tiV
TRAW
dt
dV
PPEEP
0
*
,
where PEEP
AW
= airway baseline pressure
P
TR
= tracheal pressure
V
ti
= inspired tidal volume
Range: 0.00 to 20.00 Joules/L
Resolution: 0.01 Joules/L
Accuracy: ± 10%
Note:
Requires a tracheal catheter