Mindray V12 User Manual

MAC Values Gases (Optional)
2 - 8 Addendum to V Series Operating Instructions
2.3 MAC Values
Minimum alveolar concentration (MAC) is the minimum concentration of the agent in the alveoli. It is
a basic index to indicate the depth of anesthesia. The standard ISO 80601-2-55: 2011 defines MAC as
this: alveolar concentration of an inhaled anesthetic agent that, in the absence of other anesthetic
agents and at equilibrium, prevents 50% of patients from moving in response to a standard surgical
stimulus.
TABLE 2-3 lists 1MAC of various inhaled anesthetic agents
NOTE: The data shown in TABLE 2-3 are from ISO 80601-2-55: 2011, which are
all for a healthy 40-year-old male patient.
NOTE: Des 1MAC compensated to a healthy 25-year-old patient is 7.3%.
NOTE: In actual applications, the MAC value may be affected by age, weight
and other fact
ors.
When one or more than one anesthetic agents are used, the formula for calculating MAC is:
MAC = ∑
Where N is the number of all agents (including N
2
O) that the AG module can measure, EtAgenti is the
concentration of end-tidal anesthetic agent and AgentVol
age
i is the 1MAC value corresponding to
the anesthetic agent after age correction. The value of MAC has one number after decimal, namely
one decimal place.
The formula for calculating age correction of 1MAC is:
MAC
age
= MAC
40
× 10
(-0.00269 × (age-40))
The formula above is only suitable for patients who are older than one year old. If the patient is less
than one year old, the system shall use one year to do age correction.
For example, if the patient is 60 years old, for purposes of this example, 10
(-0.00269x(60-40))
= 0.88. If the
Gas module detects 0.9% Iso and 50% N
2
O in the patient end-tidal mixed gas, the 1MAC of Iso is
1.01% and 1MAC of N
2
O is 92.4% of the 60-year-old patient based on the above age correction
formula. The MAC value is calculated as follows:
+ = 1.4
TABLE 2-3
Agent Des Iso Enf Sev Hal N
2
O
1MAC 6.65% 1.15% 1.7% 2.1% 0.77% 105%
N-1
i=0
EtAgent
i
AgentVol
i
0.9%
1.01%
50%
92.4%

Mindray V12 Specifications

General

Brand	Mindray
Model	V12
Category	Medical Equipment
Language	English