CareFusion AVEA - Patient Work of Breathing (Wobp); Ventilator Work of Breathing (Wobv)

AVEA ventilator systemsAppendix G: Advanced Pulmonary Mechanics Monitored Parameters 229
L2786 Rev. M
Ventilator Work of Breathing (WOB
V
)
Ventilator Work of Breathing (WOB
V
), is defined as the summation of airway pressure (P
AW
) minus the
baseline airway pressure (PEEP
AW
) times the change in tidal volume to the patient (∆V) during
inspiration, and normalized to the total inspiratory tidal volume (V
ti
).
If P
AW
> PEEP
AW
,
WOB
V
=
ti
Insp
AWAW
V
VPEEPP
∑
∆− )(
Range: 0.00 to 20.00 Joules/L
Resolution: 0.01 Joules/L
Accuracy: ± 10%
Patient Work of Breathing (WOB
P
) (Normalized to Delivered Tidal Volume)
Patient Work of Breathing (WOB
P
), normalized to the total inspiratory tidal volume. Patient work of
breathing is defined as the summation of two work components: work of the lung and work of the chest
wall.
WOB
P
= WOB
LUNG
+ WOB
CW
where WOB
LUNG
=
∑
∆−
Tiend
Testart
ESES
VPPEEP )(
(if PEEP
ES
> P
ES
and V > 0)
and WOBCW =
CW
P
C
V
2
2
(if PEEP
ES
> P
ES
)
Work of the lung (WOB
LUNG
) is calculated using esophageal pressure when the baseline esophageal
pressure (PEEP
ES
) is greater than the esophageal pressure (P
ES
), indicating patient effort.
Work of the chest wall (WOB
CW
) for a spontaneously breathing patient is calculated using only the portion
of the total tidal volume delivered due to a patient effort (V
P
) and the chest wall compliance (C
CW
).
Range: 0.00 to 20.00 Joules/L
Resolution: 0.01 Joules/L
Accuracy: ± 10%
Note:
Requires an esophageal balloon catheter.