5Gas measurement REFIDs for partial pressure and concentration
Paul Schluter August 5, 2013
Essential Concepts
1. Two top-level vocabulary branches for gas concentration and partial pressure measurements are defined:
MDC_CONC_AWAY for measurements obtained at the patient connector port and MDC_CONC_GASDLV
for measurements obtained in the system supplying the gas to and from the patient, with or without a
mechanical ventilator.1 The vocabulary branch REFID prefix is followed by the gas identifier and measurement
phase on the waveform, similar to convention already adopted in ISO/IEEE 11073-10101-2004.
2. For both MDC_CONC_AWAY and MDC_CONC_GASDLV, the gas measurement site may be specified by a
separate attribute in cases where greater semantic precision is required, such as OBX-20 in an HL7 V2.6
message. One of the enumerated values is identified as the ‘default’ value is OBX-20 is empty.
3. Since the delineation of the expiratory _EXP and inspiratory _INSP breath phases may be ambiguous,
additional precision can be specified by an enumerated value (that also has a specified default value).
4. The units-of-measure are conveyed by a separate attribute, e.g. OBX-6 in an HL7 V2.6 message. This may be
either a partial pressure (e.g. kPa or mm[Hg]) or concentration (% or {vol}%).
5. Gas setting identifiers are derived from the corresponding observation identifiers by appending ‘_SETTING’ to
the REFID and adding 0x01000000 to the CF_CODE10 (using the ‘über-partition’ method).
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CH4
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Ethanol
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CO

NO
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

NO2


He
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Ar
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N2
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Air
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CO2
Sevoflurane
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O2
Isoflurane
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Xe
Halothane
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
N2O
Enflurane
Volatile Agents
MAC Gas
Balance Gas
Metabolically Useful
Metabolically Consumed
Metabolically Produced
Unwanted Gas
MDC gas and phase
MDC_CONC_AWAY_gas
MDC_CONC_AWAY_gas_ET
MDC_CONC_AWAY_gas_INSP
MDC_CONC_AWAY_gas_EXP
MDC_CONC_GASDLV_gas
MDC_CONC_GASDLV_gas_INSP
MDC_CONC_GASDLV_gas_ET
MDC_FLOW_gas_FG
MDC_VOL_DELIV_gas_CASE
MDC_VOL_DELIV_gas_TOTAL
MDC_VOL_DELIV_gas_LIQUID_CASE
MDC_VOL_DELIV_gas_LIQUID_TOTAL
Desflurane
Agents/Gases
Agent
Deployment of gas partial pressure and concentration and consumption information
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1
The MDC_CONC_AWAY_ REFID prefix is already defined in ISO/IEEE 11073-10101-2004 and has been extended to support
additional gases. The new MDC_CONC_GASDLV_ prefix has been defined as a ‘synonym’ to the existing
MDC_VENT_CONC_ REFID prefix.
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The table below lists the REFIDs for the concentration (or partial pressure) and utilization of desflurane:
CF_CODE10 REFID
152024
MDC_CONC_AWAY_DESFL
152084
MDC_CONC_AWAY_DESFL_ET
152112
MDC_CONC_AWAY_DESFL_EXP
152168
MDC_CONC_AWAY_DESFL_INSP
{152052}
MDC_CONC_GASDLV_DESFL
{152140}
MDC_CONC_GASDLV_DESFL_EXP
{152200}
MDC_CONC_GASDLV_DESFL_INSP
0
MDC_VOL_DELIV_DESFL_LIQUID_CASE
0
MDC_VOL_DELIV_DESFL_LIQUID_TOTAL
SysName
Concentration | PartialPressure |
Desflurane, Gas | Airway
Concentration | PartialPressure,
EndTidal | Desflurane, Gas |
Airway
Concentration | PartialPressure,
Expiration | Desflurane, Gas |
Airway
Concentration | PartialPressure,
Inspiration | Desflurane, Gas |
Airway
Concentration | PartialPressure |
Desflurane, Gas | Gas Delivery
System
Concentration | PartialPressure,
Expiration | Desflurane, Gas |
Gas Delivery System
Concentration | PartialPressure,
Inspiration | Desflurane, Gas |
Gas Delivery System
Volume | Case, Delivered |
Desflurane, Liquid
Volume | Total, Delivered |
Desflurane, Liquid
CommonTerm
Concentration airway
desflurane
Description
Concentration airway
desflurane end tidal
Concentration of desflurane in airway gas
measured at the end of expiration
Concentration airway
desflurane expiratory
Concentration of desflurane in airway gas
measured during expiration
Concentration airway
desflurane inspiratory
Concentration of desflurane in airway gas
measured in inspiration
Concentration of desflurane in airway gas
Concentration of desflurane in airway gas
in the system conducting gas to and from
the patient
Concentration airway
Concentration of desflurane in airway gas
desflurane expiratory (gas measured during expiration in the system
delivery system)
conducting gas from the patient
Concentration airway
Concentration of desflurane in airway gas
desflurane inspiratory (gas measured during inspiration in the system
delivery system)
conducting gas to the patient
Volume (liquid) of desflurane delivered
x
during a case
Total volume (liquid) of desflurane
x
delivered
Concentration desflurane
(gas delivery system)
Notes (informative)
1. The MDC_CONC_AWAY_ REFID prefix is already defined in ISO/IEEE 11073-10101-2004 and has been extended to
support additional gases. The new MDC_CONC_GASDLV_ prefix has been defined as a ‘REFID synonym’ to the existing
MDC_VENT_CONC_ terms and includes gas measurements obtained from the system supplying the gas to the patient,
regardless of whether a ventilator is used or not. The new MDC_CONC_GASDLV_ terms will use the same CODE10 and
CF_CODE10 numeric codes. The REFID synonym relationship is indicated by {wavy braces} around either code.
Notes (normative)
1. The REFID prefix MDC_CONC_AWAY_ denotes gas concentration and partial pressure measurements obtained at the
patient connection port (MDC_GAS_MSMT_SITE_AIRWAY) unless otherwise specified by an optional measurement
location attribute, e.g. OBX-20 in an HL7 V2.6 message, using one of the following enumerated values listed below:
MDC_GAS_MSMT_SITE_UNKNOWN
MDC_GAS_MSMT_SITE_AIRWAY=
MDC_GAS_MSMT_SITE_YPIECE
MDC_GAS_MSMT_SITE_ENDOTRCH
… other breathing circuits::sites
unknown
airway adaptor (default)
Y-piece
Endotracheal
Listed under the Rosetta _GAS_MEAS_SITE_AWAY enumeration group.
2. The REFID prefix MDC_CONC_GASDLV_ denotes gas concentration and partial pressure measurements in the system
conducting the gas to and from the patient obtained at the fresh gas port (MDC_GAS_MSMT_SITE_FRESHGAS) unless
otherwise specified by an optional measurement location attribute, e.g. OBX-20 in an HL7 V2.6 message, using one of the
following enumerated values listed below:
MDC_GAS_MSMT_SITE_UNKNOWN
MDC_GAS_MSMT_SITE_FRESHGAS=
MDC_GAS_MSMT_SITE_EXHAUST
MDC_GAS_MSMT_SITE_INSP
MDC_GAS_MSMT_SITE_EXP
unknown
fresh gas (default)
exhaust
inspiratory port
expiratory port
Listed under the Rosetta _GAS_MEAS_SITE_GASDLV enumeration group.
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Notes (normative, continued)
3. The _INSP suffix denotes a numeric value representative of the entire inspiratory phase of a breath and may be further
qualified by an optional attribute that specifies the calculation method.2
MDC_METHOD_CALC_UNKNOWN
MDC_METHOD_CALC_MAX
MDC_METHOD_CALC_MIN
MDC_METHOD_CALC_MEAN
MDC_METHOD_CALC_MEAN_FLOW_WEIGHTED
MDC_METHOD_CALC_MEDIAN
MDC_METHOD_CALC_BEGIN_INSPIRATION=
not otherwise specified
maximum
minimum
mean value, time-weighted
mean value, flow weighted
median value
beginning of inspiration (default)
Listed under the Rosetta _GAS_MEAS_AOI_INSP enumeration group.3
4. The _EXP suffix denotes a numeric value representative of the entire expiratory phase of a breath and may be further
qualified by an optional attribute that specifies the calculation method.
MDC_METHOD_CALC_UNKNOWN
MDC_METHOD_CALC_MAX
MDC_METHOD_CALC_MIN
MDC_METHOD_CALC_MEAN
MDC_METHOD_CALC_MEAN_FLOW_WEIGHTED
MDC_METHOD_CALC_MEDIAN
MDC_METHOD_CALC_END_EXPIRATION=
not otherwise specified
maximum
minimum
mean value, time-weighted
mean value, flow weighted
median value
end of expiration (default)
Listed under the Rosetta _GAS_MEAS_AOI_EXP enumeration group.
5. The suffix _ET denotes ‘end tidal’, obtained at the end of the expiratory phase where the observed gas concentration and most
closely approximates the alveolar concentration, which, in turn, most closely reflects the anesthetic concentration in the
systemic blood.
6. Default values: A single default value may be identified within a list of individual enumerations and/or enumeration groups by
appending a ‘=’ after the REFID.4 If a default value is not specified, the enumerated value is considered ‘unknown’ or ‘not
otherwise specified’ if the value is not provided or the attribute is missing from the message payload.
2
Most observation identifiers in the SCADA partition support the two-bit discriminator for _MIN, _MAX and _MEAN.
‘AOI’ is the acronym for ‘Area of Interest’, first used in the FDA HL7 V3 aECG and IEEE Std 11073-10102 nomenclature.
4 Rosetta allows enumerated value sets to be constructed from zero-or-more individual enumerated values and zero-or-more
enumeration groups (e.g. _GAS_MEAS_AOI_EXP).
3
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Questions and issues:
1.
In the current proposal, the MDC_CONC_GASDLV_ is defined as a ‘REFID synonym’ to the existing
corresponding MDC_VENT_CONC_ terms, using the same numeric CODE10 and CF_CODE10. Should we
assign new numeric codes for the MDC_CONC_GASDLV terms, at the cost of consuming the remaining few
numeric codes currently left in the SCADA partition?
Norman Jones, in his 5/8 email, would prefer to see CONC_GASDLV replace VENT_CONC rather than make it a synonym.
Paul’s response: Let’s see what others who have had implementation experience using the original VENT_CONC have to
say about their semantic equivalence.
2.
In the normative notes #1 and #2 above, the measurement site was left as ‘optional’ with a pre-defined default
value defined in the standard. An alternative approach would be to make the measurement site location
mandatory. Preferences? [If we decide on ‘optional’ with a pre-defined default value, the default value will be
specified in the RTMMS.]
Norman Jones, in his 5/8 email, prefers using pre-defined default values, i.e. the non-default values are only brought in by
an optional attribute such as OBX-20 in an HL7 V2 message.
3.
During our discussion on Wednesday, the case of where ‘no gas delivery’ occurs when intravenous anesthetics
are used. What is the best way to specify that?
Norman Jones, in his 5/8 email, re-expresses this as ‘how do we represent the additional case of ‘no gas measurement
module installed’.
Paul: IEEE 11073 and PCD-01 allow ‘null-flavors’ to describe why a measurement is not available, such as ‘NAV’ for
‘(temporarily) not available’. Another approach is to omit the entire gas module (OBX VMD and descendants) in the
message if the module is not present.
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Change Summary (since 2013-05-20 preliminary distribution)
From: Wiley Stan [mailto:Stan.Wiley@draeger.com]
Sent: Thursday, July 18, 2013 7:57 AM
To: Schluter, Paul (GE Healthcare)
Cc: Schlichting, Stefan; Heesch, Ralf
Subject: RE: PCD Rosetta Terminology Mapping: Draeger Ventilator/Anesthesia Terms Checking
Hello Paul,
Please find attached our updates to the terminology spreadsheet for Draeger Medical ventilation and anesthesia products. Here are
a few comments regarding our changes:
1. Sections (marked in yellow) of the table that require further explanation from you on the term meaning:

O2 and Air as "liquid per case"
I will remove both entries. I consulted with the person who originally proposed this and he could not identify
anyone who actually did this nor preferred to use the liquid phase as a more convenient expression of O2
and/or Air use. DONE
2. Forward looking updates (marked in green):

all gases delivered TO the patient could make sense to be monitored as "delivery per case" AND "delivery
total",
I will add these terms. DONE
3. Concerns (marked in blue):

Ar may also be an unwanted gas (accumulation of Argon when a rebreathing/closed system is used in
combination with supply by O2-concentrators that have approx. 93% O2 only and approx. 5% Ar)
I will include the “dot” that you added to the chart. DONE
4. Removals (marked in red):

Remove "to" for EXP and "from" for INSP in the DES-example table (red mark) to have to explanation precise
I will make these corrections. DONE, implemented using XSLT.
With these exceptions, all other content appears ok.
Summary of specific changes to chart on first page: [changed cells highlighted with light yellow]
 Indicate that Ar is an ‘Unwanted Gas’.
 Added all AAs for MDC_VOL_DELIV_gas_CASE and MDC_VOL_DELIV_gas_TOTAL
 Removed MDC_VOL_DELIV_gas_LIQUID_CASE and MDC_VOL_DELIV_gas_LIQUID_TOTAL for N2O, O2 and Air.
 Removed He and NO for MDC_VOL_DELIV_gas_CASE and MDC_VOL_DELIV_gas_TOTAL.
Also, all Systematic Names for gas concentration now start with “Concentration | PartialPressure, … | … to indicate that they
can either express ‘concentration’ (e.g. ‘%’) or ‘partial pressure’ (e.g. ‘kPA’, ‘mm[Hg]’). [See Table on page 2.]
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Column Definitions
Column
Tbl_ID
Tbl_Desc
Group
CF_CODE10
REFID
SysName
CommonTerm
Acronym
Description
Vendor_Descriptions
Vendor_Mnemonics
Notes
ID
JR
Tbl_ID_0
Tbl_Desc_0
ROW
Extra
GasREFIDs.5c.docx
New
Exist
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Column Description
IEEE 11073-10101-2004 table identifier
Short mnemonic for table identifier
Group identifier (required for RTM but not IEEE 11073)
Context-free numeric identifier
Reference ID
Systematic Name
Common Term
Acronym
Description
Vendor descriptions (from RTM)
Vendor mnemonics (from RTM)
Paul’s editorial notes
Temporary numeric record id (from Jan’s Dec 2012 NIST table)
Original table row number (from Jan’s Dec 2012 NIST table)
Original Tbl_ID (from Jan’s Dec 2012 NIST table)
Original Tbl_Desc (from Jan’s Dec 2012 NIST table)
Original row number from IEEE 11073-10101-2004 Table A.7.4.1
A computed “extra” (indicating measurement source)
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Gas Parameter Usage
Exhaust
Exp
Fresh Gas
Insp
Ken Marks
GE Healthcare
October 12, 2009
Gas/Agent parameter measurement locations

Fresh Gas

Exhaust

Insp Limb

Exp Limb

Y-Piece

Endotracheal

Alveolar
Gas/Agent parameter measurement time spans & points

Insp Phase

Exp Phase

End Tidal

End Insp

Breath Cycle
Fresh Gas Ctrl
Insp Ctrl
Exp Ctrl
End Tidal Ctrl
Note: Titration mechanisms are
dependent upon the capabilities of the
gas delivery system. Purely pneumatic
delivery systems are only capable of
setting the fresh gas and cannot
provide closed loop compensation due
to the absence of sensing and
electronic/electro-mechanical control.
Electronic gas delivery systems (i.e.
electronic mixers and vaporizers) are
capable of all these mechanisms
because they have the ability for
remote control of gas settings via an
electronic interface and can be
controlled based on compensation from
measurements.
GasREFIDs.5c.docx
Gas/Agent Delivered
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CH4


Ethanal

CO


end
start
flow  conc dt

end
flow dt
Note: Concentrations are measured as
partial pressures. Accuracy is affected
by barometric pressure, temperature,
and humidity.
NO2
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NO
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He
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Ar
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
N2
Isoflurane


Air
Enflurane
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
CO2
Sevoflurane
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
O2
Halothane

M A C Gas
B alance Gas
M et ab o lically
U sef ul
M et ab o lically
C o nsumed
M et ab o lically
Pr o d uced
U nwant ed Gas


start
Consumption
Production
Xe
Desflurane


V o lat ile A g ent s
conc dt
Case Delivery
Total Delivery
Gas Physiological Parameters
A g ent / Gasses
end
start
conc flow
N2O




conctime  
Gas/Agent Parameter Calculations

Mean

- time wt

- flow wt

Min

Max
Gas/Agent parameter setting mechanisms
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
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