BeneVision N1 Patient Monitor Operator’s Manual
15 - 1
15
Monitoring Carbon Dioxide (CO
2
)
15.1
CO
2
Introduction
CO
2
monitoring is a continuous, non-invasive technique for determining the concentration of CO
2
in the
patient’s airway by measuring the absorption of infrared (IR) light of specific wavelengths. CO
2
has its own
absorption characteristic and the amount of light passing the gas probe depends on the concentration of the
measured CO
2
. When a specific band of IR light passes through respiratory gas samples, some of IR light will be
absorbed by the CO
2
molecules. The amount of IR light transmitted after it has been passed through the
respiratory gas sample is measured with a photodetector. From the amount of IR light measured, the
concentration of CO
2
is calculated.
CO
2
measurement are used to monitor the patient’s respiratory status. The following two methods are used for
measuring CO
2
:
■
Mainstream CO
2
measurement
Directly insert a CO
2
sensor into the patient's breathing system.
■
Sidestream/Microstream CO
2
measurement
Take a sample of the respiratory gas with a constant sample flow from the patient's airway and analyzes it
with a remote CO
2
sensor built into the Sidestream or Microstream CO
2
module.
The sidestream CO
2
module can be configured with a paramagnetic oxygen sensor. The paramagnetic oxygen
sensor measures oxygen relying on its paramagnetic properties.
CO
2
monitoring is intended for adult, pediatric and neonatal patients.
WARNING
•
N1 monitor does not support the CO
2
measurement when it is used for transporting patient though
the rotary or fixed-wing ambulance.
•
It is recommended not to measure O
2
when you’re transferring patient with the N1 monitor. Shaking
the CO
2
module during O
2
measurement may lead to distorted O
2
waveform or inaccurate O
2
measurement.
To measure CO
2
, you can use either the internal CO
2
module or the external CO
2
module. The external CO
2
module is connected to the N1 through the Modular Rack. For the connection of the N1 and the external CO
2
module, see section
2.7.1Installing the N1 or External Parameter Module into the Modular Rack
In sequence, the follows are sidestream CO
2
module, microstream CO
2
module, mainstream CO
2
module and N1
monitor.
(1)
(2)
(4)
(3)
(1)
(5)
(4)
(1)
(6)
(2)
(2)
