Presentation on theme: "Implementation of a standards-based anesthesia record compliant with the Health Level 7 (HL7) Clinical Document Architecture (CDA) Martin Hurrell, Terri."— Presentation transcript:
1 Implementation of a standards-based anesthesia record compliant with the Health Level 7 (HL7) Clinical Document Architecture (CDA)Martin Hurrell, Terri Monk, Alan NicolAndrew Norton, David Reich, John Walsh
2 Acknowledgements Thanks to: Todd Cooper , Masaaki Hirai, Melvin Reynolds, John Rhoadsand Jan Wittenber(HL7 Healthcare Devices WG)Bob Dolin and Liora Alshuler(HL7 Stuctured Documents WG)
3 “ We believe that one of the most influential developments for the practice of anaesthesia in this decade will be the introduction of a national (or possibly international) standard XML Schema for computerised anaesthetic records, and that such development should be actively promoted by appropriate professional groups.”Gardner M., Peachey T. A Standard XML Schema for computerised anaesthetic records. Anaesthesia, 2002, 57, pp
4 OpportunitiesData from the anaesthesia record may be an important resource for improving safety and quality of care e.g. NSQIPAnaesthesia Information Management Systems (AIMS) represent a valuable source of such data which is typically more comprehensive in scope and more accurate than manual equivalents.Because AIMS store data in electronic form it is potentially accessible and transferable to other systems but lack of standardisation makes this difficult in practice
5 Meaningful useEHR technology is "meaningful" when it has capabilities including e-prescribing, exchanging electronic health information to improve the quality of care, having the capacity to provide clinical decision support to support practitioner order entry and submitting clinical quality measures - and other measures - as selected by the Secretary of Health and Human Services.
6 The anaesthetic record Purposes and usesMedico-legal‘On-line’ document for decision supportFeed to the EHRAudit & researchRequirements for ‘meaningful use’Common record structure to identify clinical contextCommon terminology: for aggregation and analysisCommon model: to enable AI applications, reasoning and decision supportThe primary purpose of the anaesthetic record is to be a medico-legal record of care. However, with the advent of AIMS there are major opportunities to use information from the anaesthetic record for other purposes and so there are powerful reasons to render the electronic anaesthesia record in such a way that data can be extracted and shared.
7 AIMS in the real worldMost AIMS systems do not currently use a standard vocabulary / terminology and so the representation of information may vendor specific and / or site specificThe representation of data even within a site may not be consistent especially where free text entries are allowedThere are a number of issues surrounding the comparability of automatically recorded vital signs data e.g. pre-processing etc.Data from different systems are not organised with reference to a consistent model of the anaesthetic process
8 Aspects of a solution Issue AIMS systems do not currently use a standard vocabulary / terminology and so the representation of information may be site specific or even specific to individuals making effective aggregation difficult.ResponseDevelop and promote a standard vocabulary / terminology and a data dictionary which, together, provide unambiguous definitions of the individual terms and guidance on their intended context of use.
9 Aspects of a solution Issue There is no standard representation for the anaesthetic record and data from different systems are not organised with reference to a consistent model of the anaesthetic process.ResponseDevelop implementation guidelines tor the anaesthetic record that is based on an international standard (HL7 Clinical Document Architecture). The HL7 Anesthesiology WG is working on an implementation guide in partnership with the Structured Documents WG and Healthcare Devices WG.
10 Aspects of a solution Issue There are a number of issues surrounding the comparability of automatically recorded vital signs data e.g. detailed information concerning provenance is unavailable, differences in sampling rates, pre-processing etc.ResponseComprehensive and standardised representation in HL7 V3 CDA based on CEN ISO/IEEE standard
11 Different measurement techniques may not yield the same numbers “The objective of the study was assess the utility during anaesthesia of noninvasive continuous blood pressure measurement techniques which use intermittent oscillometric blood pressure measurement for their calibration. The assessment was performed by comparing noninvasive blood pressure with intra-arterial blood pressure.”“Accuracy and agreement of OTBP-IBP and of OTBP-ITBP were not clinically acceptable. Correlation of dynamic behavior was lower for OTBP than for ITBP. A significant effect of site difference between calibration measurements and continuous measurements was not found. It is concluded that the approach of continuous noninvasive blood pressure measurement based on the combination of two different measurement methods, in which the continuous method is calibrated by the oscillometric method, lead to clinically unacceptable accuracy and agreement in the patient group studied.”De Jong JR, Ros HH, De Lange JJ. Int J Clin Monit Comput Feb;12(1):1-10 Noninvasive continuous blood pressure measurement during anaesthesia: a clinical evaluation of a method commonly used in measuring devicesOTBP- oscillometrically calibrated tonometric blood pressureITBP - intra-arterial calibrated tonometric pressureIBP - intra-arterial blood pressure
12 Sampling rate may be important “With the rapid and universal adoption of pulse oximetry and other basic monitoring guidelines in the operating room, there is now a general perception that the practice of anesthesia is completely safe. Unfortunately, this is not true. While patient injuries from unrecognized hypoxemia are now very rare due to the continuous monitoring of patient oxygenation provided by pulse oximetry, patient injuries still occur. The remaining culprit responsible for patient morbidity is unrecognized cardiovascular lability-rapid swings in blood pressure (BP) to dangerously low or high levels.”“The use of blood pressure measurements by cuff presumes that significant alterations in blood pressure occur slowly and at predictable points in the anesthetic care of a patient. Experience with continuous patient oxygenation monitoring by pulse oximetry suggests that dangerous events can occur quickly and without warning. Why should we believe that dangerous alterations in blood pressure behave differently? Gravenstein demonstrated that significant changes in blood pressure could occur in an animal model in as short an interval as 30 seconds. Continuous monitoring of blood pressure removes even this short delay in assessment.”Swedlow DB, Continuous Blood Pressure Monitoring and Patient Safety
13 Sampling rate may be important “This study aims to evaluate possible differences in the values obtained by automated detection of hypertension, bradycardia and arterial blood oxygen desaturation between one minute and five minute automated recordings of physiologic data. The mean arterial pressure (MAP), heart rate (HR) derived from the radial pulse, and the arterial O2 saturation read by pulse oximeter (SpO2) were sampled continually in 20 patients undergoing general anesthesia. Anesthesia was induced and maintained using the same technique in all patients. Each parameter was automatically downloaded at one and five minute intervals to separate electronic spreadsheets. Hypertension was defined as MAP greater than 120 mmHg; bradycardia as HR lower than 50 bpm, and hypoxia as SpO2 < 95%. From the data presented we conclude that the five minute recording rate does not recognize the same number of clinical events as one minute recordings. This source of error must be considered when designing systems for computerized record keeping of anesthesia charts and when interpreting the data stored in electronic databases.”Gregorini P, Gallina A, Caporaloni M. The Internet Journal of Anesthesiology 1997; Vol1N4: Comparison of One Minute Versus Five Minute Sampling Rate of Physiologic Data
14 APSF DDTF / IOTA Around 4,500 specialist terms for anaeshesia - mapped to SNOMED CT
15 Standard Representation of the anaesthetic record
16 “ We believe that one of the most influential developments for the practice of anaesthesia in this decade will be the introduction of a national (or possibly international) standard XML Schema for computerised anaesthetic records, and that such development should be actively promoted by appropriate professional groups.”Gardner M., Peachey T. A Standard XML Schema for computerised anaesthetic records. Anaesthesia, 2002, 57, pp
17 XML: self-defining?XML documents are human readable although depending upon the nature of the information they contain and the way in which they have been authored they may not always be easy to understand without supplementary information. A small fragment of an XML document might look like this:<Anesthesiologist> <Firstname>John</Firstname> <Lastname>Jones</Lastname> </Anesthesiologist>‘Anesthesiologist’, ‘Firstname’ and ‘Lastname’ are tags that identify XML elementsThe elements ‘Firstname’ and ‘Lastname’ are nested within the element ‘Anesthesiologist’Deeper levels of nesting might be used to represent more complex structures.
18 Requires pre-agreement … on both However ...XML makes no commitment on:Domain specific ontological vocabularyOntological modelling primitivesOnly feasible for closed collaborationagents in a small & stable communitypages on a small & stable intranetRequires pre-agreement … on both“ In reality, XML just clears away some of the syntactical distractions so that we can get down to the big problem: how we arrive at common understandings about knowledge representation” Jon Bosak
19 Background Terminology: APSF DDTF /IOTA Terminology mainly built on SNOMED CT with new material submitted for inclusion in SNOMED. Authoring done using Protégé-OWL. Vital signs closely aligned with X.73.CDA Implementation Guide: In development by HL7 Anesthesiology WGAn implementation guide for clinicians and IT specialists who wish to create anesthetic records as XML douments that validate against the HL7 V3 R2 (R3) CDA schema. This includes vital signs representation consistent with the ISO standard and guidance on value sets for different elements of the record taken from relevant clinical terminologies (ISO nomenclature standard, IOTA, SNOMED CT)
20 Major elements of the record Record target (patient)AuthorCustodianRelated documentsEncompassing encounterCase informationOperative NoteSafety checksVital signsDrugs, fluidsEventsIntra-operative investigationsNotes
23 Example R-MIM Person Observation subject ... Person Practitioner classCode*: <= PSNdeterminerCode*: <= PSNid: II [1..1]name: EN [0..*]birthTime: TS [0..*]…Person APatientsubjectMedical HistoryPerson BPractitionerperformerThe green box at the top left depicts an entity ‘Person’ who is playing a role, ‘Patient’ and who participates in an act, ‘Observation’ as the ‘subject’. A second person plays the role ‘Practitioner’ and is scoped by (belongs to) an ‘Organization’ (which might be specifically identified). This person participates in the observation act as the performer of the act. Other attributes can be defined for each class to add more information and specificity to the model.1..1 patientPerson1..1 patientPatientclassCode*: <= PATid*: II [1..1]addr: AD [0..1]telecom: TEL [0..*]ObservationclassCode* <= xymoodCode* <= xyid*: II [1..1]...subjecttypeCode*: <= SBJPerson1..1 practitionerPractitionerclassCode*: <= PRTid*: II [1..1]telecom: TEL [0..*]playedByperformertypeCode*: <= PRFtime: IVL<TS>scopedByOrganization
24 XML hierarchy Prescription author subject Patient id addr telecom PersonClassCode*: <=PSNdeterminerCode*: <=PSNName: EN [0..*]birthTime: TS [0..*] …EntryPointidPrescriptionclassCode* <=SBADMmoodCode) <=RQOId*: || [1..1]Text: ED [0..1]statusCode: CS CNE [1..1] <=activeaddr1..1 patientLivingSubjecttelecom1..1 patientPatientClassCode*: <=PATId*: || [1..1]addr: AD [0..*]Telecom: TEL [0..*] …PersonsubjecttypeCode*: <=SBJname1..1 assignedEntityCMET (Assigned)R_AssignedPerson[identified]COCT_MT090101authortypeCode*: <=AUTTime: IVL<TS>
26 What is the CDA?The CDA is a document markup standard for the structure and semantics of exchanged "clinical documents".A clinical document is a documentation of observations and other services with the following characteristics:PersistenceStewardshipPotential for authenticationContextWholenessHuman readabilityA CDA document is a defined and complete information object that can exist outside of a message, and can include text, images, sounds, and other multimedia content.
27 What is the CDA?The CDA Header identifies and classifies the document and provides information on:Authentication,EncounterPatientProviderThe body contains the clinical reportCDA body structuressection, paragraph, list, table, captionstructures, including <body> can have own confidentiality, originatorCDA body entriestext, link, codes, content, images (multi-media)
28 CDA Release 2 Information Model StartHereHeaderBodyParticipantsDoc ID&TypeContextSections/ HeadingsClinical Statements/Coded EntriesExtlRefs
31 Why x.73?“The CEN ISO/IEEE standards are the only coherent standards that address medical device interconnectivity and have resulted in a single set of internationally harmonized standards that (a) have been developed and adopted via clinical and technical contributions from within ISO and CEN member countries and (b) include contributions from the most significant manufacturers”Reynolds M.I. (2008) Device Interfaces. In J. Stonemetz & K. Ruskin (Eds.), Anesthesia Informatics (pp ). Springer-Verlag, London
32 Interoperability Functional Semantic Shared architectures, methods, frameworks and technologiesCEN ISO/IEEE 11073: Domain Information Model (DIM)SemanticShared data types, terminologies and coding systemsCEN ISO/IEEE 11073: Nomenclature
33 x.73 DIM: Medical PackageThe VMO is the base class for all medical-related objects in the model. It provides consistent naming and identification across the Medical Package model.The VMD object is an abstraction for a medical-related subsystem (e.g., hardware or even pure software) of a medical device. Characteristics of this subsystem (e.g., modes, versions) are captured in this object. At the same time, the VMD object is a container for objects representing measurement and status information.The Channel object is used for grouping Metric objects and, thus, allows hierarchical information organization. The Channel object is not mandatory for representation of Metric objects in a VMD.
34 x.73 DIM: Medical Package Patient monitor BP module NIBP values as complex numeric
35 x.73 Nomenclature Nomenclature: general aims The purpose of the device nomenclature is to support an identification scheme for the Channel, VMD, and MDS objects of the DIM.The system provides enough information to support the data from the Metric and Channel objects, without replicating this information. For example, in the case of an airway gas analyzer, such a device may be measuring one, two, or more gases. The exact gases measured can be divined from the Metric object of the DIM that this device will be generating, i.e., O2, CO2, N2O, etc. and to include this level of detail in the device nomenclature is redundant.
36 x.73 Nomenclature: Coding [context-free] Nomenclature Code == (Code Block number * 216 ) + [contextsensitive]Term Code, where Term Code has the range 216.Example: the context-free nomenclature code for a term in code block number 1 whose term code=4100is equal to (( 1 * 216 ) ) = = (which uniquely identifies the SpO2 monitor term
37 x.73 Nomenclature Attributes Description/DefinitionPurposeInterpretabilityPresenceSystematic, or DIMnameAn organization of differentiating, relational descriptorsFormal or semiformal but human-readable derivationShall be unambiguousMandatoryCommon termA brief description of the nameHuman-readable identification or efficient lookupShould be unambiguousOptionalAcronymAn abbreviated form of the nameMnemonic or parametric abbreviationDescription/ DefinitionA long, or sentence, form of the nameHuman-readable and as understandable as possibleShall be unambiguous with the exception of synonymsReference IDA symbolic, programmatic form of the termDevelopment of application program interfaces (APIs)Code[Alpha]numeric identifierHuman- and machine- read-able and efficiently processable by machinesShall be unique, but context-sensitive parts are permitted; see 7.2
38 x.73 Nomenclature Base concepts Analyzer : devices that manipulate or interpret acquired data in order to produce derivative resultsCalculator: devices that perform calculations upon raw or derived dataFilter: physical particle or chemical filtersGenerator: devices that generate physical quantities such as heat, moisture, electrical activity, etc.Meter : devices that perform measurement functions on physical properties such as current, electrical potential, flow, etc.)Monitor : devices that both acquire data and analyze itStimulator: devices that generate physical quantities such as heat, moisture, electrical activity, etc.System: instruments that consist of transducive, analytical, and therapeutic components. An anesthesia system and most ventilators would fall into this device class
39 x.73 Nomenclature Mapping to IOTA & SNOMED CT SNOMED IDSystematic nameCommon termAcronymDescription/DefinitionReference IDCodeRate | Beats | Heart | CVSHeart rateHRRate of cardiac beatsMDC_ECG_HEART_RATE16770An organization of differentiating, relational descriptorsA symbolic, programmatic form of the termFormal or semiformal but human-readable derivationDevelopment of application program interfaces (APIs)
40 ModellingUse Case(s)Activity Diagram(s)GlossaryUML Model (X73 and Drug Modelling, included) MDHT (Model Drive Health Tools)Constrained CDA ModelImplementation GuideJava Library
41 ConclusionsIn order to facilitate / ensure interoperability with EMRs and to allow data from anesthetic records to be fully utilised for audit the pre-requisites are:A standard nomenclature that fully and unambiguously describes data collected from patient-connected devices during anaesthesiaA standard way to represent the anaesthetic record that provides full contextual information that will allow data derived from devices to be analysed and interpreted correctlyIt is hoped that the combination of the IOTA / SNOMED CT terms for anaesthesia, the CEN ISO/IEEE standard and the implementation of the HL7 V3 CDA-compliant anaesthesia record specification proposed by the HL7 Anesthesiology WG will support these aims
43 HL7 WG GAS“Out of cycle” meeting, London, 16th. / 17th. February
44 HL7 WG GAS Projects Pre-operative assessment domain analysis model Anesthetic record domain analysis modelCDA Implementation Guide for Anaesthetic Record including references to IHE technical frameworkProof of concept – transfer of data from MGH AIMS to US NSQIP database via generic representation
45 APSF DDTF / IOTA Around 4,500 specialist terms for anaeshesia - mapped to SNOMED CT
46 Challenges of information transfer - Devices - Output is often specific to the device manufacturer reflecting an internal information modelParameters may be named in different ways rather than being taken from a standard nomenclature
49 x.73 Nomenclature First set of differentiating criteria Semantic link "has measured property: "Applicable descriptors include the following:ConcentrationElectricalPotentialFlowMulti-ParameterNegativePressureRateResistanceTemperatureVolume
50 x.73 Nomenclature Second set of differentiating criteria Semantic link "has target: "Applicable descriptors include the following:AirwayBloodBodyBrainGasHeartInfusionIntra-AortaLungMulti-GasMusclePhysiologic (for devices that are very general and not body-system-specific)RenalRespSkin/TissueUrine
51 x.73 Nomenclature Third set of differentiating criteria Semantic link “device type: "Applicable descriptorsinclude the following:ChannelMDSNon-specificVMDVMD Attributes (optional)AcousticChemicalElectricalImpedanceMagneticNuclearOpticalThermal