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Chapter18
Measurement of Anesthetic Gases
18.1
Overview
Anesthetic gas (AG) is used to measure the anesthetic gases and breathing gases for the patients under
anesthesia. This module provides the end-tidal value (et) and inhalation value (in) of the following gases:
CO2 —— measure EtCO2 (maximum exhalation value – measured in respiration).
N2O —— laughing gas.
O2 —— optional.
AwRR —— respiration per minute (rpm)
The system can display four waveforms for an anesthetic gas at a time, including CO2 waveform, O2
waveform, N2O waveform, and anesthetic agent gas waveform. By default, the CO2 waveform is
displayed.
The system can display such parameters as CO2, N2O, O2, and AA (the anesthetic agent being monitored:
DES, ISO, ENF, SEV, or HAL), including both the inhalation and exhalation value, and also display the
MAC (minimum alveolar concentration), BAL (balance gas), and AwRR.
Names of Parameters:
CO2: carbon dioxide.
N2O: nitrous oxide (laughing gas).
O2: oxygen.
AwRR: airway respiration rate (respiration per minute: rpm).
Halothame: HAL.
Isoflurane: ISO.
Enflurane: ENF.
Sevoflurane: SEV.
Desflurane: DES.
Caution
Only the waveform and value of a single anesthetic agent are displayed at a time.
18.2
Measurement Principle and Work Process
Measurement Principle for Anesthetic Gases:
Measure the AG concentration based on the AG ability of absorbing infrared rays. All gases to be measured
