Mindray SV300 - Page 110

7-2
For mainstream CO
2
module, besides the above mentioned CO
2
waveform and EtCO
2
monitored parameter, the measurement also provides:
1. V- CO
2
loop
2. Monitored parameters:
 Vdaw: airway dead space.
 Vdaw/TVe: ratio of airway dead space to tidal volume.
 Vtalv: alveolar tidal ventilation.
 V’alv: alveolar minute ventilation.
 slopeCO
2
: CO
2
rising slope.
 V’CO
2
: CO
2
elimination.
 VeCO
2
: exhaled CO
2
volume.
 ViCO
2
: inspired CO
2
volume.
Some monitored parameters of the mainstream CO
2
module (Vdaw, Vdaw/Tve, Vtalv, V’alv,
slopeCO
2
, V’CO2, VeCO
2
, ViCO
2
) have reference significance only when the patient is in
stable ventilation status. Stable ventilation status refers to the following situations:
 Patient is at rest for at least 30 minutes.
 Mechanical ventilation parameters (RR, TV, and etc) remain unchanged.
 No operations that may affect the patient’s gas exchange or metabolism.
Some monitored parameters of the mainstream CO
2
module may be inaccurate in the
following situations. The affected parameters include Vdaw, Vdaw/Tve, Vtalv, V’alv,
slopeCO
2
, V’CO2, VeCO
2
, ViCO
2
.
 System leakage
 Patient ventilation condition is unstable
 High frequency ventilation (HFV)
 Breathing frequency greater than 35/min
 Neonate patient
 Non-invasive ventilation type
 Other circumstance causing wrong CO
2
and Flow measurements