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VitalSigns IG

terjebless edited this page Sep 26, 2022 · 1 revision

About the Norwegian national vital signs profiles

The Norwegian national vital signs profiles have been designed for exchange of the most important vital signs between systems, devices, and healthcare organizations in the national Norwegian healthcare system.

The initiative for the development of the profiles came from the regional health authority for Northern Norway (Helse Nord RHF) for the use case of exchanging the most commonly needed vital signs between an electronic charting and medication system, and the core electronic healthcare record (EHR) and patient management system. Additional initial use cases included exchanging vital signs between the EHR and the radiology system (RIS/PACS), neonatal and neonatal intensive care (NICU) system, the pharmacy and medication production system, and entry and lookup through multiple specialized mobile applications for bedside use. In the subsequent development of the profiles uses cases for home monitoring of patients, patient-provided data (e.g. from smartwatches or other personal health devices), and exchange between healthcare organizations (primary care, specialists, hospitals, and care homes, etc.) have been considered. National quality and research registries have been identified as a possible future use case.

The profiles have been developed limited by the principle that all profiles should derive from the international vital signs profiles provided by HL7 International and then constrain or extend these as needed. Additionally, as Norway has adopted SNOMED CT as the standard healthcare related terminology system, the development has adopted the constraint that all ValueSets, "Magic Value", and model bindings should be expressed as SNOMED CT pre-coordinated codes.

Since the EHR system in question (DIPS Arena) uses OpenEHR archetypes as its internal information model, and there are both international and Norwegian national archetypes for vital signs that are clinically validated, the Norwegian national archetypes for the relevant vital signs were chosen as the logical model for the profiles. The electronic charting and medication system (IMDsoft Metavision) uses a proprietary information model which will need to be mapped to the logical model expressed in the FHIR profiles, but was consulted in order to identify any impedances in the models.[^1]

Other information models for these vital signs have been consulted, and while there are several different approaches none have been identified that have the capability to express any concept or relationship that the current profiles are not capable of expressing. Of particular interest here are the CIMI revised vital signs profiles [TODO: link] and the NHS profiles [TODO: link]. CIMI have entirely independently taken an approach remarkably similar to these profiles (which we take as validating this approach), while the NHS has developed their propfiles in conjunction with, and seemingly as a primary use case, profiles for the NEWS2 score [TODO: link]. NEWS2 is a standard screening tool in Norwegian hospitals and it is likely that a future revision of these profiles will need to be adapted to work well in this context.

[ TODO: SNOMED CT, CodeSystem, ValueSet, "Model of meaning" bindings … ]

Profiles

The use case-derived vital signs covered are:

  • Body height
  • Body weight
  • Body temperature
  • Blood pressure
  • Pulse
  • Heart rate
  • Respiration rate
  • Oxygen saturation

Body height

Name Description
Concept Height/Length
Description Height, or body length, is measured from crown of head to sole of foot. Height is measured with the individual in a standing position and body length in a recumbent position.
Keywords shrinkage, increase, decrease, height loss, height, length, growth
Purpose To record the length of the body from crown of head to sole of foot of an individual - either measured or approximated, and either in a standing or recumbent position.
Use To be used for recording the measured height or body length of an individual at any point in time. A statement identifying the physical incompleteness of the body can be recorded in the 'Confounding factors' protocol element, if required. This is the usual archetype to be used for a typical measurement of height or body length, independent of the clinical setting.

Can also be used for recording an approximation of height or body length measurement in a clinical scenario where it is not possible to measure an accurate height or length - for example, measuring an uncooperative child. This is not modelled explicitly in the archetype as the openEHR Reference model allows approximations for any Quantity data type by setting the attribute Magnitude_status to the value '~'. [ TODO: How to express this in FHIR? ] At implementation, for example, an application user interface could allow clinicians to select an appropriately labelled check box adjacent to the Height data field to indicate that the recorded height is an approximation, rather than actual.

In general, length measurements are recommended for children under 2 years of age and individuals who cannot stand; height measurements for all others.

When recording the first length of an infant shortly after birth, "birth length", use the event "Birth". [ TODO: How to express this in FHIR? ]
Misuse Not to be used to record an adjusted height, a calculation of the full height of a person who for example are missing parts or all of the lower limbs, or has contractures. A calculated body weight may be based on measurements of other body parts and an algorithm. Use specific profiles for this purpose.

Not to be used to record growth velocity.

Not to be used to record the length of an object or specific body part.

Body weight

Name Description
Concept Body weight
Description Measurement of the body weight of an individual.
Keywords weight, gain, loss, increase, decrease, mass, estimate, actual
Purpose To record the body weight of an individual - both actual and approximate.
Use To be used for recording the actual measurement of body weight, including when the individual is missing a body part due to a congenital cause or after surgical removal. A statement identifying the physical incompleteness of the body can be recorded in the 'Confounding factors' data element, if required. This is the usual archetype to be used for a typical measurement of weight, for example self-measured by the individual at home, a clinician measurement in a clinic/hospital, or a fitness instructor in a gymnasium.

Can also be used for recording an approximation of body weight measurement in a clinical scenario where it is not possible to measure accurately body weight - for example, weighing an uncooperative child, or estimating the weight of an unborn fetus (where the 'subject of data' is the Fetus and recording occurs within the mother's health record). This is not modelled explicitly in the archetype as the openEHR Reference model allows approximations for any Quantity data type by setting the attribute Magnitude_status to the value '~'. [ TODO: How to express this in FHIR? ] At implementation, for example, an application user interface could allow clinicians to select an appropriately labelled check box adjacent to the Weight data field to indicate that the recorded weight is an approximation, rather than actual.

To be used for recording weight change, that is, either weight loss or weight gain. This can currently be modelled by constraining the 'any event' to an interval with associated mathematical function of increase or decrease, as appropriate. [ TODO: Can this be expressed in FHIR? ]
Misuse Not to be used to record a calculated body weight, such as an estimation of the body weight of a person with one or more limbs missing. A calculated body weight may be based on, some or all of, the measured body weight, other body measurements and an algorithm. Use other profiles for this purpose.

Not to be used to record the weight of a body part or other object.

Body temperature

Name Description
Name Body temperature
Description A measurement of the body temperature, which is a surrogate for the core body temperature of the individual.
Keywords temperature, body, core, fever, hypothermia, hyperthermia
Purpose To record the measured temperature of a person - as a surrogate for the core body temperature.
Use Used for recording the measurement of an individual's body temperature, which is a surrogate for the core body temperature of the individual.

Additional clusters can be included to provide additional state data - including environmental conditions and exertion details, where appropriate.

Please Note: The site and method of recording may need to be displayed to the end user to facilitate accurate interpretation of the temperature recorded.
Misuse This profile is not to be used to record the temperature of any other object.

This profile is not to be used to record the temperature of a part of the body in isolation e.g. temperature of the sole of the foot as a part of chronic diabetes management.

Blood pressure

Name Description
Concept Blood pressure
Description The local measurement of arterial blood pressure which is a surrogate for arterial pressure in the systemic circulation.

Most commonly, use of the term 'blood pressure' refers to measurement of brachial artery pressure in the upper arm.
Keywords observations, measurement, bp, vital signs, mean arterial pressure, pulse pressure, systolic, diastolic, RR, NIBP
Purpose To record the systemic arterial blood pressure of an individual.
Use Use to record all representations of systemic arterial blood pressure measurement, no matter which method or body location is used to record it.

The archetype is intended to capture blood pressure measurements in all clinical scenarios - for example: self-measurement with a home blood pressure machine; an emergency assessment of systolic using palpation and a sphygmomanometer; measurements taken in clinical consultations or during exercise stress testing; and a series of measurements made by a machine in Intensive Care.

There is a rich state model that supports interpretation of measurements through identifying patient position, exercise, confounding factors and angle of a tilt table in research.

[ FIXME: These are OpenEHR-specific features. Does FHIR have an equivalent? ] Named events have been limited to average over a 24 hour period, however templates can further constrain the default 'any event' to cater for specific requirements for blood pressure measurements such as recording Blood Pressure against specific points in time, or over a range of intervals (+/- mathematical functions).
Misuse Not to be used to record the measurement of arterial blood pressure which is NOT a surrogate for arterial pressure in the systemic circulation eg specific measurement of right pulmonary artery pressure. Use a specific intravascular_pressure profile in this situation.

Not to be used to record measurements of intravenous pressure. Use the appropriate specialisations of an intravascular_pressure profile in this situation.

Pulse

[ TODO: The distinguished descriptions for pulse and heart rate are TBD ]

Heart rate

[ TODO: The distinguished descriptions for pulse and heart rate are TBD ]

Respiration rate

Name Description
Concept Respiration
Description The characteristics of spontaneous breathing by an individual.
Keywords respirations, breathing, breath, resps, respiration
Purpose To record the characteristics of spontaneous breathing by an individual.
Use Use to record the observed and measured characteristics of spontaneous breathing by an individual, including respiratory rate, depth and rhythm.

Respirations are commonly recorded as one component of vital signs.
Misuse Not to be used to record the physical examination of the respiratory system - use a physical examination family of profiles for this purpose, such as profiles for exam-chest or exam-lung.

Not to be used to record other measurements related to breathing - use specific profiles for the purpose, for example pulse_oximetry.

Not to be used to record functional assessments of breathing - use specific profiles for the purpose, for example pulmonary_function.

Not to be used for recording details about individuals who are undergoing assisted ventilation.

Oxygen saturation

Name Description
Concept Pulse oximetry
Description Blood oxygen and related measurements, measured by pulse oximetry or pulse CO-oximetry.
Keywords oxygen, oxygenation, saturation, SpO2, spMet, spCO, spOC, carboxyhaemoglobin, methaemoglobin, pulse, oximeter, oximetry, concentration, partial, pressure, non-invasive, vital, O2, SaO₂, SaO2, sat, sats, hypoxaemia
Purpose To record blood oxygen and related measurements, measured by pulse oximetry or pulse CO-oximetry.
Use Use to record blood oxygen and related measurements, measured by pulse oximetry or pulse CO-oximetry.

Waveforms should be recorded here when used to document quality of the blood gas measurement.
Misuse Not used for other non-invasive blood gas measurements such as transcutaneous CO₂, lateral end-tidal CO₂ or non-invasive cerebral oximetry.

Not to be used for recording plethysmography. Use another appropriate profile for this purpose.

Not to be used for recording another type of measurement, such as pulse rate, where the recording device also provides this. This should be recorded in a separate profile, appropriate for that particular measurement to allow consistent querying. In this example, record the pulse rate in the pulse profile.

Not to be used to record any peripheral blood gas measurement that involves direct contact with blood. For example, PaO₂ and PaCO₂ should be recorded using a laboratory_test_result profile.

Not to be used to record invasive blood gas measurement. For example, arterial (SaO₂), venous (SvO₂) oxygen saturation or Oxygen content (CaOC) which are usually determined by invasive methods such as laboratory blood gases or vascular catheter devices. These should also be recorded in a laboratory_test_result profile.

Extensions

Extension Profile Description
NoDomainVitalSignsObservationActiveHeatingExtension NoDomainVitalSignsObservationBodyTemp  Description of active measures that affect the measured body temperature, e.g. heating blankets, cold compresses, ice baths, or ECMO to raise core temperature of hypothermic patients.
NoDomainVitalSignsObservationBloodPressureBodyPositionExtension NoDomainVitalSignsObservationBloodpressure  The position of the individual at the time of measurement.
NoDomainVitalSignsObservationBloodPressureDiastolicFormulaExtension NoDomainVitalSignsObservationBloodpressure  Formula used to calculate the diastolic pressure from mean arterial pressure (if recorded in data).
NoDomainVitalSignsObservationBloodPressureMeanArterialFormulaExtension NoDomainVitalSignsObservationBloodpressure  Formula used to calculate the Mean Arterial Pressure (if recorded in data).
NoDomainVitalSignsObservationBloodPressureSystolicFormulaExtension NoDomainVitalSignsObservationBloodpressure  Formula used to calculate the systolic pressure from from mean arterial pressure (if recorded in data).
NoDomainVitalSignsObservationBodyExposureExtension NoDomainVitalSignsObservationBodyTemp  The degree of exposure of the individual at the time of measurement.
NoDomainVitalSignsObservationBodyHeightBodyPositionExtension NoDomainVitalSignsObservationBodyHeight  Position of individual when measured.
NoDomainVitalSignsObservationCharacterOfHeartRateExtension NoDomainVitalSignsObservationHeartRate  Description of the character of the heart beat. Coding with a terminology is desired, where possible. For example: full, thready, bounding, slow rising, or collapsing. Multiple terms may be recorded.
NoDomainVitalSignsObservationClinicalDescriptionExtension
  • NoDomainVitalSignsObservationHeartRate
  • NoDomainVitalSignsObservationPulse
 
Narrative description about the pulse or heart beat.
NoDomainVitalSignsObservationClothingStateExtension NoDomainVitalSignsObservationBodyTemp  The degree of exposure of the individual at the time of measurement.
NoDomainVitalSignsObservationConfoundingFactorExtension
  • NoDomainVitalSignsObservationBloodpressure
  • NoDomainVitalSignsObservationBodyHeight
  • NoDomainVitalSignsObservationBodyTemp
  • NoDomainVitalSignsObservationBodyWeight
  • NoDomainVitalSignsObservationHeartRate
  • NoDomainVitalSignsObservationOxygenSaturation
  • NoDomainVitalSignsObservationPulse
  • NoDomainVitalSignsObservationRespirationRate
 
Additional issues or factors that may impact on the measurement that are not captured in other fields.
NoDomainVitalSignsObservationCuffSizeExtension NoDomainVitalSignsObservationBloodpressure  The size of the cuff used for blood pressure measurement.
NoDomainVitalSignsObservationDaysSinceMenstruationStartExtension NoDomainVitalSignsObservationBodyTemp  Current day of the menstrual cycle. The first day of menstruation is considered to be Day 1 of each menstrual cycle.
NoDomainVitalSignsObservationDiastolicEndPointExtension NoDomainVitalSignsObservationBloodpressure  Record which Korotkoff sound is used for determining diastolic pressure using auscultative method.
NoDomainVitalSignsObservationHeadTiltExtension NoDomainVitalSignsObservationBloodpressure  The craniocaudal tilt of the surface on which the person is lying at the time of measurement.
NoDomainVitalSignsObservationHeartRateBodyPositionExtension NoDomainVitalSignsObservationHeartRate  The body position of the subject during the observation.
NoDomainVitalSignsObservationHeartRhythmExtension NoDomainVitalSignsObservationHeartRate  Regularity of the pulse or heart beat.
NoDomainVitalSignsObservationHeartRhythmIrregularityExtension NoDomainVitalSignsObservationHeartRate  More specific pattern of an irregular pulse or heart beat. Selection of a value from this value set is only valid if the rhythm is 'Irregular'.
NoDomainVitalSignsObservationHeatingDeviceExtension NoDomainVitalSignsObservationBodyTemp  Details regarding the environment or measures that actively affected the temperature during the measurement.
NoDomainVitalSignsObservationInspiredOxygenExtension NoDomainVitalSignsObservationOxygenSaturation  Details of the amount of oxygen available to the subject at the time of observation. Assumed values of 21% oxygen concentration, Fi0₂ of 0.21 and oxygen flow rate of 0 l/min or 0 ml/min.
NoDomainVitalSignsObservationOxygenSaturationExtension NoDomainVitalSignsObservationOxygenSaturation  [ FIXME: What is this? ]
NoDomainVitalSignsObservationPrePostduktalExtension NoDomainVitalSignsObservationOxygenSaturation  Sensor site relative to the ductus arteriosus in neonates, to determine whether the blood supply to limb of the sensor site is pre- or post-ductal in cases of patent ductus arteriosus.
NoDomainVitalSignsObservationRespirationDepthExtension NoDomainVitalSignsObservationRespirationRate  The depth of spontaneous breathing.
NoDomainVitalSignsObservationRespirationPatternExtension NoDomainVitalSignsObservationRespirationRate  [ FIXME: What is this? ]
NoDomainVitalSignsObservationRespirationRateBodyPositionExtension NoDomainVitalSignsObservationRespirationRate  The body position of the individual during the observation.
NoDomainVitalSignsObservationRespirationRegularityExtension NoDomainVitalSignsObservationRespirationRate  The regularity of spontaneous breathing.
NoDomainVitalSignsObservationSleepStatusExtension NoDomainVitalSignsObservationBloodpressure  Sleep status - supports interpretation of 24 hour ambulatory blood pressure records.
NoDomainVitalSignsObservationSpontaneousBreathingExtension NoDomainVitalSignsObservationRespirationRate  Observation of spontaneous respiration. This data element may be useful in extreme situations where a formal measurement of respiration rate is not possible. For example: a subject is unconscious and distant to the observer, such as trapped in a car or has fallen down a cliff. Presence of respiration can be implied if the 'Rate' >0 breaths/min.

Value sets

  • NoDomainVitalSignsObservationBloodPressureBodyPositionValueSet
  • NoDomainVitalSignsObservationBloodPressureBodySiteValueSet
  • NoDomainVitalSignsObservationBodyExposureValueSet
  • NoDomainVitalSignsObservationBodyHeightBodyPositionValueSet
  • NoDomainVitalSignsObservationBodyTempBodySiteValueSet
  • NoDomainVitalSignsObservationClothingStateValueSet
  • NoDomainVitalSignsObservationCuffsizeValueSet
  • NoDomainVitalSignsObservationDiastolicEndpointValueSet
  • NoDomainVitalSignsObservationHeartRateBodyPositionValueSet
  • NoDomainVitalSignsObservationHeartRateBodySiteValueSet
  • NoDomainVitalSignsObservationHeartRhythmIrregularity
  • NoDomainVitalSignsObservationHeartRhythmValueSet
  • NoDomainVitalSignsObservationPrePostduktalValueSet
  • NoDomainVitalSignsObservationRespirationRateBodyPositionValueSet
  • NoDomainVitalSignsObservationRespirationRateDepthValueSet
  • NoDomainVitalSignsObservationRespirationRegularityValueSet
  • NoDomainVitalSignsObservationSleepStatusValueSet
  • NoDomainVitalSignsObservationSpontaneousBreathingValueSet

Footnotes

[^1]: For example, while the then-current OpenEHR archetypes treated pulse and heartrate as a single concept, the charting system treated them as related but separate. Consultation with clinicians in acute and emergency care revealed that while most healthcare settings will treat the two interchangeably, within this clinical setting the two are very distinct concepts and need to be kept separate. A patient may have a heart rate of 180 beats per minute but no pulse due to a ruptured aorta or a heart rythm that is so irregular that no measurable pulse wave is generated through the peripheral arterial system. Pulse deficit has consequently been identified as a possible future profile to include.