Procedure. Anesthesia concept

pissces · January 22, 2020, 6:46am

Hi, I am anesthesiologist who want to map anesthesia procedure concepts correctly to CDM.
The problem is one case of general anesthesia consists of several concepts. I just wonder how all these attributes put on one procedure occurrence.

This is the typical case of general anesthesia, procedure.
On arrival to the operating room, patient received ✱ lidocaine 40 mg and 1% propofol 80 mg for anesthesia induction, and ① rapid sequence ② tracheal intubation was performed after ③ muscle relaxation with rocuronium 80 mg IV. ④ Sevoflurane 1 to 2 vol%air was administered for maintenance of anesthesia.

① Rapid sequence induction
② Endotracheal anesthesia
③ General anesthesia and muscle relaxant
④Inhalation general anesthesia

✱ Intravenous induction

QI_omop · January 22, 2020, 3:40pm

I just wonder how all these attributes put on one procedure occurrence.

They are not put in one procedure occurrence. They get put into multiple records in Procedure_Occurrence table. Each concept represents one record. If you want to link them together, you need to use Fact_Relationship table. However, Fact_Relationship table does not give you a high level view of the entire process. Right now, two new tables - Episode and Episode_Event tables are introduced in Oncology Extension model. There is thinking now to use these two tables to represent other area besides oncology such as this one

Christian_Reich · January 22, 2020, 5:02pm

Hang on, @QI_omop, let’s first understand what’s going on.

@pissces: We usually don’t record intention. So, things like “induction” are not explicitly stated, instead, the lidocaine 40mg iv etc. speaks for itself. So, in your case you would just create DRUG_EXPOSURE records of those drugs.

Would that work?

pissces · January 23, 2020, 1:22am

Thanks. @Christian_Reich

Of course the drug should go to DRUG_EXPOSURE records. But ‘induction’ is not an ‘intention’ but type of procedure. As you can see fig. 2., there are four types of induction of general anesthesia and intravenous induction is one of them.

Thanks @QI_omop.
Anesthesia procedures really need those tables in Oncology Extension.

Christian_Reich · January 23, 2020, 8:12am

@pissces:

Look. You are saying “for anesthesia induction”, “for maintenance”. This is what I meant by “intention”. You could also call it “purpose” or “step in a process”. From an OMOP perspective, the procedure for all these is “Drug injection”, and the Drug Exposure is “Lidocain”, “Propofol” and all those. The fact that the anesthesiologist has something in mind when doing these injections is not the intent of data capture in the OMOP CDM. Because it happens in the mind of the anesthesiologist, not in body of the patient.

Of course, you could do what @QI_omop said, and that is a legitimate way of capturing this. Except no analytical tool will have a clue what it means and even look for it. So, you would solve the problem in your own data set, but you couldn’t network with anybody else.

Does that make sense? Can you share the analytical use case you want to investigate? That would help with giving you the right advice.

pissces · January 28, 2020, 4:00am

Thank you for your help.

Let’s say I want to know the outcome according to the induction type such as intravenous induction vs. inhalational induction. This is common subject of anesthesia research.

These are few examples

ncbi.nlm.nih.gov

Inhalational versus Intravenous Induction of Anesthesia in Children with a High Risk of Perioperative Respiratory Adverse Events: A Randomized Controlled Trial.

A Ramgolam, GL Hall, G Zhang, M Hegarty and BS von Ungern-Sternberg, Anesthesiology, 2018 06

Limited evidence suggests that children have a lower incidence of perioperative respiratory adverse events when intravenous propofol is used compared with inhalational sevoflurane for the anesthesia induction. Limiting these events can improve recovery time as well as decreasing surgery waitlists and healthcare costs. This single center open-label randomized controlled trial assessed the impact of the anesthesia induction technique on the occurrence of perioperative respiratory adverse events in children at high risk of those events.Children (N = 300; 0 to 8 yr) with at least two clinically relevant risk factors for perioperative respiratory adverse events and deemed suitable for either technique of anesthesia induction were recruited and randomized to either intravenous propofol or inhalational sevoflurane. The primary outcome was the difference in the rate of occurrence of perioperative respiratory adverse events between children receiving intravenous induction and those receiving inhalation induction of anesthesia.Children receiving intravenous propofol were significantly less likely to experience perioperative respiratory adverse events compared with those who received inhalational sevoflurane after adjusting for age, sex, American Society of Anesthesiologists physical status and weight (perioperative respiratory adverse event: 39/149 [26%] vs. 64/149 [43%], relative risk [RR]: 1.7, 95% CI: 1.2 to 2.3, P = 0.002, respiratory adverse events at induction: 16/149 [11%] vs. 47/149 [32%], RR: 3.06, 95% CI: 1.8 to 5. 2, P < 0.001).Where clinically appropriate, anesthesiologists should consider using an intravenous propofol induction technique in children who are at high risk of experiencing perioperative respiratory adverse events.An online visual overview is available for this article at http://links.lww.com/ALN/B725.

ncbi.nlm.nih.gov

Intravenous versus inhalational anaesthesia for paediatric outpatient surgery.

AC Ortiz, AN Atallah, D Matos and EM da Silva, The Cochrane database of systematic reviews, Feb 2014 07

Ambulatory or outpatient anaesthesia is performed in patients who are discharged on the same day as their surgery. Perioperative complications such as postoperative nausea and vomiting (PONV), postoperative behavioural disturbances and cardiorespiratory complications should be minimized in ambulatory anaesthesia. The choice of anaesthetic agents and techniques can influence the occurrence of these complications and thus delay in discharge.The objective of this review was to evaluate the risk of complications (the risk of postoperative nausea and vomiting (PONV), admission or readmission to hospital, postoperative behavioural disturbances and perioperative respiratory and cardiovascular complications) and recovery times (time to discharge from recovery ward and time to discharge from hospital) comparing the use of intravenous to inhalational anaesthesia for paediatric outpatient surgery.We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (2013, Issue 8); MEDLINE (1948 to 1 October 2013); EMBASE (1974 to 1 October 2013); Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS) (1982 to 1 October 2013). We also handsearched relevant journals and searched the reference lists of the articles identified.We included randomized controlled trials comparing paediatric outpatient surgery using intravenous versus inhalational anaesthesia.Two review authors independently assessed trial quality and extracted the data. When necessary, we requested additional information and clarification of published data from the authors of individual trials.We included 16 trials that involved 900 children in this review. Half of all the studies did not describe the generation of randomized sequence and most studies did not describe adequate allocation sequence concealment. The included studies showed variability in the types and combinations of drugs and the duration of anaesthesia, limiting the meta-analysis and interpretation of the results.For the induction and maintenance of anaesthesia there was a significant difference favouring intravenous anaesthesia with propofol; the incidence of PONV was 32.6% for sevoflurane and 16.1% for propofol (odds ratio (OR) 2.96; 95% confidence interval (CI) 1.35 to 6.49, four studies, 176 children, low quality evidence). The risk of postoperative behavioural disturbances also favoured intravenous anaesthesiaas the incidence was 24.7% for sevoflurane and 11.5% for propofol (OR 2.67; 95% CI 1.14 to 6.23, four studies, 176 children, very low quality evidence). There were no differences between groups in the risk of intraoperative and postoperative respiratory and cardiovascular complications (OR 0.75; 95% CI 0.27 to 2.13, three studies,130 children, very low quality evidence) and there was no difference in the time to recovery from anaesthesia and discharge from hospital. These results should be interpreted with caution due to heterogeneity between studies in the type and duration of operations, types of reported complications and the high risk of bias in almost all studies. Two studies (105 participants) compared halothane to propofol and showed heterogeneity in duration of anaesthesia and in the type of ambulatory procedure. For the risk of PONV the results of the studies were conflicting, and for the risks of intraoperative and postoperative complications there were no significant differences between the groups.For the maintenance of anaesthesia there was a significant difference favouring anaesthesia with propofol, with or without nitrous oxide (N2O), when compared to thiopentone and halothane + N2O (OR 3.23; 95% CI 1.49 to 7.02, four studies, 176 children, low quality evidence; and OR 7.44; 95% CI 2.60 to 21.26, two studies, 87 children, low quality evidence), respectively. For the time to discharge from the recovery room, there were no significant differences between groups. The studies were performed with different ambulatory surgeries and a high risk of bias.Four studies (250 participants) compared the induction of anaesthesia by the inhalational or intravenous route, with inhalational anaesthesia for maintenance, and found no significant differences between groups in all outcomes (the risk of PONV, behavioural disturbances, respiratory and cardiovascular complications and time to discharge from recovery room). Meta-analysis was not done in this comparison because of significant clinical heterogeneity.Readmission to hospital was not reported in any of the included studies. No other adverse effects were reported.There is insufficient evidence to determine whether intravenous anaesthesia with propofol for induction and maintenance of anaesthesia in paediatric outpatients undergoing surgery reduces the risk of postoperative nausea and vomiting and the risk of behavioural disturbances compared with inhaled anaesthesia. This evidence is of poor quality. More high-quality studies are needed to compare the different types of anaesthesia in different subsets of children undergoing ambulatory surgery.

If there is a drug-exposure record of Propofol without a procedure record of induction type(id:4082996) on the same day when anesthesia was delivered, we could presume Propofol was injected for anesthesia induction, but the problem is Propol could be used at other instance not for anesthesia induction for example treatment for nausea or seizure.
For precision of information, we just can not assume Propofol was induction agent just because it was injected on the same day as anesthesia delivered. That why we need concept specific to induction procedure type.
I hope this helps.

Chris_Knoll · January 28, 2020, 5:21am

I think inhaled vs. injection can be identified via the dose form of the drug in drug exposure.

I think what @Christian_Reich is saying is that the CDM focuses on what happens to the person, not what was in the head of the person doing the drug administration (were they thinking they were treating a seizure or administering an anesthesia? The CDM answer is: it doesn’t matter, only that the drug entered the body). The CDM concern is definitely ‘how’ the drug entered the body, but this can be captured at the drug exposure level, and not linked over to a procedure.

pissces · January 28, 2020, 5:56am

Well, then I just wonder what is the use of concept intravenous anesthesia induction?
Also, we could identify inhaled vs. injection but we need to differentiate iv drug is used for anesthesia induction or other treatment to see the outcome according to the induction method.
Both Inhaled anesthesia and iv drug can be used in one patient, then we don’t know which one is induction agent?
That’s why we need both procedure and drug exposure record, respectively.
Maybe I don’t understand CDM well and Anesthesia procedure may not be suitable for CDM.
Thank you for your help.

Christian_Reich · January 28, 2020, 6:50am

As @Chris_Knoll says: It’s the fact that matters. Not the intention. The fact is that the patient got lidocain and propofol IV or inhalant.

Absolutely, and we want to support it. IV lidocain injection is done by using a drug product that is formulated for injection. These are all the descendants of RxNorm 35604127 Lidocaine Injection. The inhalants are children of 21113643 Lidocaine Inhalant Solution. For propofol it looks like there isn’t any inhalant on the market, only Propofol Injection. Is that correct?

@pissces: If you need to understand how the data are represented and used for analytics please look at the Book of OHDSI or the Tutorial. Both will help you to wrap you head around it. Or keep asking here, but that will be the slow route.

Chris_Knoll · January 28, 2020, 7:24am

Just to answer this one: one might imagine a use case where they want to exclude people who experienced an intravenous anesthesia induction of any kind. The drug doesn’t matter, it’s just the scientific question says you don’t want people who underwent anesthesia. So, that concept will identify those people. it’s better than having to go through saying ‘not exposed to drug x for anesthesia induction, not exposed to drug y for anesthesia induction, not exposed to drug z for anesthesia induction’, etc etc, you can see the pain that would be.

pissces · January 28, 2020, 9:18am

@Chris_Knoll
Exactly, I am not saying propofol itself map to intravenous induction. What I am saying is the case itself map to intravenous induction to include those who received intravenous induction with any kind of drug.
Patient 1 received propofol for anesthesia induction.
Patient 2 received midazolam for anesthesia induction.
Patient 1. drug exposure record for propofol
Procedure record for intravenous anesthesia induction

Patient 2. Drug exposure record for midazolam
Procedure record for intravenous anesthesia induction

Then I can use concept intravenous anesthesia induction for cohort generation.

Chris_Knoll · January 28, 2020, 4:45pm

So, I think a procedure record and a drug record out of the single event of ‘received propofol for anesthesia induction’ is what I’d do.

This is similar to the case of ‘chemotherapy’…saying I am undergoing chemotherapy doesn’t say anything about the drugs involved in the chemo, but it’s definitely an important observation in a patients procedure history that they underwent chemo. So, if you received a source record saying ‘chemo with cytoxan’, I think it would be appropriate to record the start of chemo in the procedure_occurrence and the individual drugs used at the various times in drug_exposure’. Some sources, you don’t get the drugs, you just know they underwent chemo. So you couldn’t do a drug study on these people but you could potentially exclude them from another clinical question by nature that they did have chemo.

Note, I don’t want to start an argument here around ‘chemo is a drug exposure’, I was just explaining how I think of it and how I compare it to your case of anesthesia.

AntoineLamer · January 28, 2020, 5:34pm

Dear @pissces,

Do you plan to use a standard vocabulary (as SNOMED) to characterize these facts ?
I also work on the mapping of operating room data to OMOP. I finished the structural mapping and am currently dealing with semantic mapping (we used many local vocabularies in France).

pissces · January 31, 2020, 1:51am

Hi @AntoineLamer

Yes, I want. I visited your site. It was interesting. I will attend OHDSI Europe 2020 at Oxford. I hope to see you there and hear from you in person.