Anesthesia, sedation and analgesia procedures classification

2024-Feb-28

As part of the review of 1263452006 |Anesthesia and/or sedation procedure (procedure)| hierarchy, and after revision of several topics previously commented, we can see a clear need for properly classify those procedures in SNOMED CT. While there are a few different classifications from different authors with slights differences, I'd like to ask for the current and more widely accepted classification in order to properly remodel such concepts.

Here, a broad classification for General anesthesia from the British Journal of Anaesthesia (2002) which may serve as a starting point for discussion:

Currently in SCT, 27372005 |Regional anesthesia (procedure)| is a subtype of 386761002 |Local anesthesia (procedure)|.

Although the objective of this discussion is to start with the broad classification of Anesthesia procedures, you can also review the discussion about Nerve block vs Local anesthetic nerve block (procedure) which was documented previuosly in a tracker document (https://snomed.atlassian.net/wiki/display/IHTSDO1/Content+Project+Tracker+Documents?preview=%2F18777631%2F18777817%2FProject+1_Artf221500-RestructuringofLocalanesthesia_Inception_20141202.docx) from 2014.

Q: Are Local anesthesia and regional anesthesia siblings?

Q2: Should 27372005 |Regional anesthesia (procedure)| be a subtype of 386761002 |Local anesthesia (procedure)|?

Q3: Should Sedation procedures and Analgesia procedures be classified under 50697003 |Administration of general anesthetic (procedure)|?

Q4: Current grouping of 373266007 |Anesthetic (substance)| and 372614000 |Sedative (substance)| in SNOMED CT is updated or should it be corrected?

Feel free to write your answers in this space.

Comments

Steven Dain

Mar 13, 2024

Victor Medina Andrew Marchant Patrick McCormick My opinions

Q1: I'm OK with that

Q2: No

Q3: No, should be siblings of the top Anaesthesia (IMO), Anaesthesia is sibling with sedation with children intravenous analgosedation, intravenous sedation, inhalational sedation, inhalational analgosedation. Ether analgesia would put as a child of analgo sedation.

Q4: 373266007 |Anesthetic (substance)| is outdated. It needs new term in there General Inhalational Anesthetic (Substance) as a child under General anesthetic and as a sibling of intravenous anesthetic. I would put Ketamine under intravenous anesthetic.

Under General Intravenous anesthetics I would remove Alfentanil, Fentanyl, Sufentanil and Remifentanil and their derivatives as these are opiates and not Anesthetics. Interestingly Opiate (substance) doesn't exist in SNOMED, but 373529000 | Substance with opioid receptor agonist mechanism of action (substance) (but what is a Morphinan - Wikipedia?) a pharmacologist needs to look through this.! I have never heard of this term

Andrew Marchant

Mar 13, 2024

Similarly to Steven:

Q1. Expressing LA and RA as siblings is reasonable.

Q2. Depends what is meant by "Local Anesthesia". I agree with Steven because I think it means "anesthesia which is local to the surgical site". For RA to be a subset of LA, LA would have to be defined as "anesthetic procedure using (principally) a local anesthetic drug", which is another way the term is used in everyday speech (often the distinction doesn't matter).

Q3. There is already a higher-order term "410011004 | Administration of anesthesia AND/OR sedation (procedure)", which has sedative procedures as children.

Q4. 373266007 |Anesthetic (substance) seems to encompass anything with qualities which are somehow described as anaesthetic (encompassing tribromoethanol, sevoflurane and bupivacaine). 372752008 | Central nervous system agent (substance) and 373266007 |Anesthetic (substance) are at the same level. 372614000 |Sedative is further down the tree, below 372752008 | Central nervous system agent (substance). Perhaps, then, General Anesthetics (substances rather than procedures) would be a subgroup under 9680003 | Central depressant (substance), as 372614000 |Sedative already is? (using the UK release for convenience).

Steven's point about Alfentanil, etc., is well made although common usage outside Anaesthesia does not entirely make the distinction clear.

Victor Medina

Mar 18, 2024

So far, agreement about hierarchization of Local and Regional anesthesia: These two concepts should be siblings.

About 410011004 | Administration of anesthesia AND/OR sedation (procedure). Being a Classification derived component, will be deactivated and split into Administration of anesthesia and Administration of sedation. After responses, I understand that these two concepts should be siblings.

Substances need review for classification and standardization.

Ed Cheetham

Mar 19, 2024

If I might offer an alternative view here, since there are always trade-offs...

The Local/Regional question:

This is a good example of what Rector characterised (1999 - section 3) as the tension between linguistics, 'clinical pragmatics' and logical concept representation in terminology management. Andrew offers two possible meanings for "Local Anesthesia":

"anesthesia which is local to the surgical site"
"anesthetic procedure using (principally) a local anesthetic drug"

386761002 has been modelled consistent with definition 2 for more than 20 years (grouping and method have varied a bit, but direct_substance=local_anaesthetic has been a steady feature). So long as it is modelled this way (and is regarded as sufficiently defined), and so long as 27372005 |Regional anesthesia (procedure)| also includes direct_substance=local_anaesthetic in its formal definition, in SNOMED CT's opinion the latter will (AFAIK) always classify as a subtype of the former.

As such the formal definition (Rectors 'logical concept representation') is at odds with what appears to be the preferred 'clinical pragmatic' definition (a disjunction of 'topical' and 'infiltration'). If there is truly a desire to organise SNOMED CT according to the pragmatic preference then it is worth considering the costs:

If 386761002 |Local anesthesia (procedure)| survives the changes without inactivation:

How will users know that << 386761002 no longer specifies the set of 'all procedure using (principally) a local anesthetic drug'?
How will 386761002 be modelled to ensure that it subsumes all (and only) topical and infiltration LA procedures, and what is the cost/benefit to users of doing so?

If 386761002 |Local anesthesia (procedure)| is inactivated as a result of the proposed changes:

What are the sensible active replacements?
What will be the impact on prior use of 386761002?
Will there still be a place for the term 'local anaesthesia' (very useful, I would have thought, for NLP entity-matching of narrative text and for 'vague but still machine-processable' clinical documentation), and what will the relationship of any of the active replacements be to their topical, infiltration and regional anaesthesia counterparts?

Regarding 410011004 | Administration of anesthesia AND/OR sedation (procedure):

Why inactivate it? Time and effort was spent 12 months ago applying a number of GCI axioms to its stated definition making it the formal disjunction of the proposed replacements - which are already siblings. How would the removal of 410011004 improve the data?

Regarding the original Q4, is it possible to explain how any proposed changes will be reconciled with the approaches taken in the substance redesign project (notably the use of the 'has_disposition' attribute) and that taken in the product redesign work (notably the 'plays role' attribute)? Whilst only the former is likely to affect the substance and procedure content directly it would be helpful to know what design philosophy is being used.

Thanks - Ed

(edited)