User's Manual Part 3

6-15
6.3. Respiration, Carbon Dioxide and Multi-Gas (Anesthetic Agents) Monitoring
Capnography (CO2) and Respiration or Capnography, Respiration and Multi-Gas Anesthetic
Agent sidestream options, can be equipped with the 3880. Both options feature automatic
barometric pressure compensation.
The CO2/Respiration only unit is a built in, integrated option to the 3880 MRI monitor unit and
operable to the full 30,000 gauss rating of the 3880. This built in CO2/Respiration only unit is
not for use with anesthetic agents as such gases may affect the accuracy of the CO2
measurements.
The Multi-Gas unit (P/N 3886) is a separate external unit to the 3880 monitor which connects to
the 3880 unit for display of CO2/Respiration, O2 (Fast Paramagnetic), N2O, and anesthetic
agents. The 3886 Multi-Gas unit is rated for up to 600 Gauss operation.
Side-stream gas analysis is a continuous, non-invasive technique for determining the
concentration of CO
2
and other gases in the patient’s airway by measuring (non-dispersive)
absorption of infrared (IR) light of specific wavelengths. CO
2
has its own IR absorption
characteristic and the amount of IR absorbed depends on the concentration of the sampled gas.
When a specific band of IR light is passed through respiratory gas samples, some of IR light will
be absorbed by the gas molecules. The amount of IR light transmitted after it has been passed
through the respiratory gas sample is measured with an IR detector. From the amount of IR
light measured, the concentration of gases is calculated. The built in CO2 only option utilizes
two IR filters, one for reference and one for detection of CO2.
With the Multi-Gas option, other gases, such as N2O, and anesthetic agent(s) likewise have
known specific IR absorption wavelengths. The Multi-Gas agent/N2O analyzer includes nine IR
filters for each of five agents, N2O, a CO2 specific filter and two reference filters. This allows the
detection and measurement of all seven gases via IR absorption. Please see Appendix E for
further technical details.
Respiration rate is the frequency of peak (end tidal) CO
2
measurements per minute. A breath is
defined as a change in the CO
2
signal which exceeds 1% (8 mmHg). All concentrations are
measured and displayed breath by breath.
! WARNING
• Do not measure CO
2
or Multi-Gasses in the presence of aerosol pharmaceuticals.
• Anesthetic agents may be flammable and explosive. Use extreme caution and follow all
of your hospitals policy for working with and around Anesthetic Agents.
• Leakages in the sampling system or breathing circuit may cause the displayed values to
be significantly low.
• Nasal cannulas can display values significantly low when a patient is breathing through
the mouth.
• Always allow the system to warm up prior to connecting the sampling line and cannula
to the patient.
• Connect the scavenging exhaust tubing when patients receive inhalation anesthetics.
• Too high of a scavenge vacuum level can result in inaccurate readings or internal
damage.
• Mainstream cyclical pressure of 10 kPa can damage the 3880 since this system uses
sidestream technology as the measurement technique.
• Do not allow the tubing to become kinked or altered in a manner that would reduce flow.
• CO
2
patient tubing and its associated components are intended for single-patient use