[elif]

Thank you for sharing this. In the program guide it says a temperature reading of > 42 degrees or an oxygen saturation of < 90 are the thresholds for a MET call. Is there a basis for these specific values or are they general approximations?

[danieltrembath]

Chosen by the emergency doctors who headed the project. Sats being the more important. Those are default thresholds, but each they can be overridden per-patient.

As I understand it there is a lot of communication going between emergency teams and specialists around the world and the odd pre-publication paper. This work has come out of the RMH's emergency department. Full credit goes to Dr Martin Dutch who's idea the whole thing was. As best I know he came to the idea (tracking sats via cheap electronics to spot risky covid patients) quite early, and independently. He also built an initial prototype. I'm a developer who was brought in to build it out into a working system during the first phase of Australia's covid outbreak.

PS: If you're thinking about using the system, it's worth having a read through the redcap_design_overview.md documentation. Building something like this in a research-survey tool was not easy and there's plenty of things in the design that will be head-scratchers when seen for the first time. Now that the model is proven we'll hopefully build out a 'real' version of it at some point.

We're happy to assist where we can to see other hospitals (particularly resource-constrained ones) pick it up. The operating costs are very low (a server + sms gateway cost). The hospital has also open sourced some other covid tools developed this year.

[bearsnowstorm]

What other tools did the hospital open source this year?

[danieltrembath]

There is a tool for screening patients as they arrive at the hospital. This has been running at a number of facilities this year.

https://github.com/rmhcovid/screentool

And we have another project for operating drive-through testing clinics that will hopefully be published in the next few weeks. It has been shared through hospital channels but isn’t up on github yet.

[danieltrembath]

bearsnowstorm, I just had a chance to read your background. If you or your department is interested in talking with our emergency specialists by all means say hello.

[Aeolun]

Temperature higher than 42 (e.g. 43) is described on Wikipedia[1] as:

> Normally death, or there may be serious brain damage, continuous convulsions and shock. Cardio-respiratory collapse will likely occur.

It seems that that's a little bit late to consider calling the hospital?

[1]: https://en.wikipedia.org/wiki/Human_body_temperature#Fever

[distant_hat]

42C is 107F, it is way too high it seems.

[danieltrembath]

Thanks for querying this. I raised it with the team and their response is up above.

[httpsterio]

When internal body temperatures start nearing 40 degrees celcius, there starts to be a real risk of dehydration. Anything above that starts nearing deathly levels, generally a temperature of 42 celcius will start leading to permanent brain damage and death. So uh, if a body temp is already at 42 it starts to be a bit late going to the hospital :D

[danieltrembath]

That is a very good point :)

The figures are actually set per-patient. But that 42 as placeholder does seem odd. There are two lower thresholds that trigger before getting to that one. But I’ll flag it with the clinician regardless. Thank you.

[danieltrembath]

Thanks httpsterio. I checked in with the team and posted the details further up the chain.

[danieltrembath]

Thanks everyone (below) who was concerned about whether the 42degrees figure was too high. A doctor on the team confirmed that figure was on purpose, but for peculiar reasons, and was kind enough to offer a few pages of explanation which I'll do my best to summarise. Any errors below are mine, not theirs.

The purpose of the program is to watch a large population of COVID patients who are not sick enough to warrant being in hospital. Miserable no doubt, but OK. The purpose of the monitoring is to identify those who are getting sicker before they have become very sick.

The goal is not to have the system calling ambulances. It can (and has) but we should be spotting degradation and reacting before it comes to that. To that end we measure three vitals (temperature, heart rate and oxygen saturation). They are not each equal predictors of the sickness we wish to spot. They are also not linear indicators of sickness.

We have three levels of response to patient vitals. There are some automated suggestions for patient comfort at the bottom end. There is the metcall at the top end. But the most important is the Clinical Review in the middle. Clinical Review connects the patient with a clinician by phone so that we can dig into their situation.

Temperature it turns out is not an especially good marker of the sickness we need to find in the group of people we are monitoring. "[with temperature] there is a U shape association with mortality, but the error bars at any point a super wide". It has some correlation, but high temperatures are not a good enough predictor of what we're trying to spot. Oxygen Saturation is good because of what COVID can cause in the lungs. That can happen without the patient being aware of it so it's critical to what we must spot.

Infection alone wont bring someone up to a temperature that high (we're monitoring people with covid, not amphetamines overdoses or desert marathons). So COVID monitoring is not dependant on spotting patient temperatures that high, and if it was that high it would not be on account of the virus. For those patients this isn't the only healthcare the patient is involved with.

So why do we bother to give the patient a thermometer? It's easy to measure. The devices are cheap and readily available. It's useful at the slightly-elevated end and helps us recommend paracetamol if/when appropriate. Tracking a patient temperature over their monitoring period feeds data back into the ongoing analysis of the virus. We ask a number of supplementary questions of the patients each day. Hopefully there will be trends.

So finally, why is there a temperature threshold at 42 degrees? More an accident of the project history. We'd built the multi-step thresholds for each of the measurements, but it turned out the highest temperature one really isn't applicable in our project. The patient hits Clinical Review well before they get up to those temperatures. It may come out completely in a newer version.

Also they added "Whilst not completely analogous, we draw your attention to the NEWS2 illness scoring system used by the National Health Service (UK) (https://www.mdcalc.com/national-early-warning-score-news-2). The system uses various parameters to calculate a score of 'how sick they are'. Whilst many measurements have a 3+ (add 3 to the score) threshold values, the NHS does not have a temperature threshold value 'worthy' of contributing 3 points to your illness score."