5Gas Measurement Refids for Partial Pressure and Concentration

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_AWAYfor 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 prefixis 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 ‘überpartition’ method).

Deployment of gas partial pressure and concentration and consumption information

Agents/Gases / Agent / Desflurane / Enflurane / Halothane / Isoflurane / Sevoflurane / N2O / Xe / O2 / CO2 / Air / N2 / Ar / He / NO / NO2 / CO / Ethanol / CH4
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 /  /  /  /  / 

The table below lists the REFIDs for the concentration (or partial pressure) and utilization of desflurane:

CF_CODE10 / REFID / SysName / CommonTerm / Description
152024 / MDC_CONC_AWAY_DESFL / Concentration |PartialPressure | Desflurane, Gas | Airway / Concentration airway desflurane / Concentration of desflurane in airway gas
152084 / MDC_CONC_AWAY_DESFL_ET / Concentration | PartialPressure,EndTidal | Desflurane, Gas | Airway / Concentration airway desflurane end tidal / Concentration of desflurane in airway gas measured at the end of expiration
152112 / MDC_CONC_AWAY_DESFL_EXP / Concentration | PartialPressure, Expiration | Desflurane, Gas | Airway / Concentration airway desflurane expiratory / Concentration of desflurane in airway gas measured during expiration
152168 / MDC_CONC_AWAY_DESFL_INSP / Concentration | PartialPressure, Inspiration | Desflurane, Gas | Airway / Concentration airway desflurane inspiratory / Concentration of desflurane in airway gas measured in inspiration
{152052} / MDC_CONC_GASDLV_DESFL / Concentration | PartialPressure| Desflurane, Gas | Gas Delivery System / Concentration desflurane (gas delivery system) / Concentration of desflurane in airway gas in the system conducting gas to and from the patient
{152140} / MDC_CONC_GASDLV_DESFL_EXP / Concentration | PartialPressure, Expiration | Desflurane, Gas | Gas Delivery System / Concentration airway desflurane expiratory (gas delivery system) / Concentration of desflurane in airway gas measured during expiration in the system conducting gasfrom the patient
{152200} / MDC_CONC_GASDLV_DESFL_INSP / Concentration | PartialPressure, Inspiration | Desflurane, Gas | Gas Delivery System / Concentration airway desflurane inspiratory (gas delivery system) / Concentration of desflurane in airway gas measured during inspiration in the system conducting gas to the patient
0 / MDC_VOL_DELIV_DESFL_LIQUID_CASE / Volume | Case, Delivered | Desflurane, Liquid / x / Volume (liquid) of desflurane delivered during a case
0 / MDC_VOL_DELIV_DESFL_LIQUID_TOTAL / Volume | Total, Delivered | Desflurane, Liquid / x / Total volume (liquid) of desflurane delivered

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. TheREFID 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 anoptional 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 patientobtained 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.

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 qualifiedby 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.

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.

Change Summary (since 2013-05-20 preliminary distribution)

From: Wiley Stan [mailto:
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:
2. 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

1. Forward looking updates (marked in green):
2. 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):
4. 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
5. Removals (marked in red):
6. 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.]

Column Definitions

Column / New / Exist / Column Description
Tbl_ID /  /  / IEEE 11073-10101-2004 table identifier
Tbl_Desc /  / Short mnemonic for table identifier
Group /  /  / Group identifier (required for RTM but not IEEE 11073)
CF_CODE10 /  /  / Context-free numeric identifier
REFID /  /  / Reference ID
SysName /  /  / Systematic Name
CommonTerm /  /  / Common Term
Acronym /  /  / Acronym
Description /  /  / Description
Vendor_Descriptions /  / Vendor descriptions (from RTM)
Vendor_Mnemonics /  / Vendor mnemonics (from RTM)
Notes /  / Paul’s editorial notes
ID /  / Temporary numeric record id (from Jan’s Dec 2012 NIST table)
JR /  / Original table row number (from Jan’s Dec 2012 NIST table)
Tbl_ID_0 /  / Original Tbl_ID (from Jan’s Dec 2012 NIST table)
Tbl_Desc_0 /  / Original Tbl_Desc (from Jan’s Dec 2012 NIST table)
ROW /  / Original row number from IEEE 11073-10101-2004 Table A.7.4.1
Extra / A computed “extra” (indicating measurement source)

GasREFIDs.5c.docx- 1 -2013-08-05T14

[1] The MDC_CONC_AWAY_ REFID prefix is already defined in ISO/IEEE 11073-10101-2004 and has been extended to support additionalgases. The new MDC_CONC_GASDLV_ prefix has been defined as a ‘synonym’ to the existing MDC_VENT_CONC_ REFID prefix.

[2] Most observation identifiers in the SCADA partition support the two-bit discriminator for _MIN, _MAX and _MEAN.

[3] ‘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).