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Mapping Mechanical Ventilation Parameters

(Gigi Lipori) #1

I wanted to see if anyone might be able to advise on mapping of the clinical parameters below related to vents and anesthesia machines. I took a stab at some of them, but I’m not sure if they’re great matches. Additionally, I didn’t know how to go about the time parameters. I truly appreciate any thoughts, Gigi

Terms are below, and excel worksheet is attached.

ETCO2 - Oral/Nasal
RESP RATE - Adult Mech
RESP RATE - Adult Spont
RESP RATE - Peds Mech
RESP RATE - Peds Spont

vent terms.xls (27 KB)

(Vlad Korsik) #2

hello. here some insights from me

Why do not simply use Procedure occurrence table and populate procedure_concept_id with 4164571 45851008 Positive end expiratory pressure ventilation therapy, initiation and management instead of using Measurement table? The table maybe used to put extra parameters of PEEP, is it your use case?

As for me, it is better to evaluate source and find linked values, directly describes the Device applied in the clinical settings. After that - map these source_values to the Procedure domain.

The issue with time aspects is a tricky one(someone experienced may disagree probably )
If you need to preserve Start and End times of any event, here is my solution (NB for 6th CDM version)
a) To define start time use the procedure_datetime in Procedure occurrence table with for e.g. 4145647 266700009 Assisted breathing Procedure Standard Valid Procedure SNOMED
b) Store the end time in Value_as_datetime in Observation table and populate the observation_concept_id with 40482217 442137000 Completion time of procedure Observable Entity Standard Valid Observation SNOMED and use the field
and obs_event_field_concept_id to modify the procedure, the first one will contain the exact id in the Procedure occurrence table to be detalized by the observation, the 2nd field specifies the exact filed in the Procedure table to be modified.
I will call for experienced guys to resolve the problem @Alexdavv @Dymshyts @zhuk @Polina_Talapova
, please give your thoughts plus corrections .

(Oleg Zhuk) #3

Hi, Gigi,
your mapping for ETCO2; ETCO2 - Oral/Nasal; PIP; RESP RATE; RESP RATE - Adult Mech; RESP RATE - Adult Spont; RESP RATE - Peds Mech; RESP RATE - Peds Spont is totally fine

For PEEP I would rather use 3022875 Positive end expiratory pressure setting Ventilator.
For TIDAL VOLUME I would rather use 21490854 Tidal volume Ventilator --on ventilator
For TIDAL VOLUME EXHALED I would rather go with 21490752 Tidal volume expired Respiratory system airway or something like that

Reasons to change mapping
  • From a clinical perspective, there are different ‘PEEPs’: one is intrinsic or auto-PEEP ( 3035822 Intrinsic PEEP Respiratory system), one is extrinsic PEEP or external PEEP, applied by ventilator ( 42528515 Extrinsic PEEP Respiratory system) And the third type is total PEEP, which is calculated by some ventilators with help of measured autoPEEP and external PEEP. However, you can’t always differentiate between all those types and mostly all you have is just a ventilator parameter - which, I suggest, would be 3022875.

  • Tidal volume is constant only in few modes of ventilation. Even during ventilation in these modes, measured TV can differ from set one. In most clinical situations this parameter is changing dynamically. In some cases desired tidal volume are not achieved with high inspiratory pressures and the ventilator delivers less volume. I am not familiar with your data (which mode of ventilation is used, are we talking about measured or set values, etc) that’s why I would rather change the mapping to a less granular concept

  • Your option for tidal volume exhaled is an alarm limit - real volume can be more, can be less, or can be equal to the alarm limit. TIDAL VOLUME EXHALED suggests that it is a real data, not an alarm limit

RESP DEVICE - what do you mean?

Ventilation duration problem: It’s been a while :slight_smile:
We always struggle to store a duration of something, but there are options: one was described by @Vlad_Korsik, another one (and even two) can be found here

(Robyn Rubin) #4

We are looking for other measurement concepts :
with regards to peep:
PS above PEEP and PC above PEEP
with regards to BIPAP
We would appreciate help finding these concepts

(Oleg Zhuk) #5

Hi, @robyn.rubin. Not the ones that easy to find.

BiPAP RR: (sounds like Respiratory Rate). You can use:
3007469 19834-1 Breath rate setting Ventilator
37053455 LP188587-2 Breaths.controlled setting
depending on your machine specification.

PC above PEEP: 44806798 814021000000102 Inspiratory positive airway pressure
Can’t find good LOINC for it - I think it is still possible to use less specific SNOMED

BiPAP PC: 4101694 27913002 Peak inspiratory pressure
Can’t find good LOINC for it - I think it is still possible to use less specific SNOMED

PS above PEEP: 3000461 20079-0 Pressure support setting Ventilator

You just need to keep in mind that your calculations are ‘above PEEP’ or add PEEP to your values (in that case you will get Peak inspiratory pressure and/or inspiratory positive airway pressure)

The second best option is to create 2bil+ concepts for those source codes and make them standard but I think it possible to use OMOP standard concepts.

(Robyn Rubin) #6

Thanks, this is helpful