The Royal Melbourne hospital in Australia is using pulse oximeters to manage COVID positive patients in their own homes. The program was setup in March this year to manage a large number of patients remotely (cost/safety).
The patients take their own measurements with a pulse oximeter and digital thermometer (both off the shelf consumer items). The person is prompted via SMS and submit their vitals via website. A software system orchestrates all of this and alerts patients and clinicians to anyone with worrying numbers.
This keeps beds free at the hospital, but still gets the small percentage of patients back to hospital that get really sick.
It also does all the other boring monitoring and administrative work needed when you're checking up on lots of real people.
Full disclosure. I worked on this project. A version has been open sourced and if you're a hospital or other medical service you're welcome to use our work. We're publishing improvements as we go.
https://github.com/rmhcovid/txtmon
Using simple standalone devices and a low-coding platform already in use by hospitals (REDCap) the whole project was crash-built in a couple of weeks and is saving lives. That platform has many shortcomings (messier even than Excel), but there's various medical/privacy rules that make more traditional development unattractive for quickly prototyping. It's been a rewarding project to work on despite many frustrations.
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?
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.
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
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."
Off-topic, but an inventor of the Pulse Oximeter recently passed away [1]:
"Takuo Aoyagi, a Japanese engineer whose pioneering work in the 1970s led to the modern pulse oximeter, a lifesaving device that clips on a finger and shows the level of oxygen in the blood and that has become a critical tool in the fight against the novel coronavirus, died on April 18 in Tokyo. He was 84."
I measured myself at home in Mexico City and got 93%. I got kind of worried, knowing people sick with COVID-19 can have very low saturation levels without realising it. Then I remembered I was standing at about 2200 m above sea level. Lots of unexpected weirdness happens at high altutude
I’ll be honest, a lot if the portable oxygen saturation monitors seem to report slightly out of range readings. It often picks up after a few minutes, I suspect they are calibrated poorly tbh.
94-98% is the desired range.
even holding your breath for couple seconds will tank saturation, so pretty likely high altitude will do the same until your breathing adjusts to compensate
At the time they reported that there were mentions of it in an iOS 14 leak, but it wasn't clear if it would be a software update to existing watches (somehow able to detect it with existing heartrate hardware) or in a watch hardware revision. Since it wasn't mentioned in the watchOS news at WWDC, looks like it'll be new hardware.
Either that or the code they found in iOS 14 was related to the health app and support for 3rd party oximiters, but that's not how the 9to5 post frames it so best I can do is take their word for it.
Just bought a Huawei Honor 5 watch with pulse oximeter and heart rate functions: numbers seem correct and the device is fast: results in 5 seconds for O2 sat; almost instantaneous for HR.
Compare to Apple Watch HR function which takes at least 10 seconds to show result. Simultaneous side-by-side comparison of 2 devices: near identical numbers.
Wow they finally did it. After the hardware being there for _years_ they managed to get around to enabling the software. I already jettisoned them for Garmin after waiting so long.
Does anyone know, in general, if a watch device already has a pulse measurement LED system, whether that can also serve as a pulse ox measurement? or are they different hardware requirements?
The problem with pulse oximeters is the people who need them often can't use them. Yes I know it's not meant as a medical device.
My dad has COPD and IPF but he can't use the SPO2 meter on the Samsung phone I gave him (and Samsung disabled the SPO2 function for Canada). A Garmin VivoSmart 4 can't give a decent reading on him or me and it takes forever. Part of the problem is blood flow dad's fingers are ice cold due to his condition.
My dad uses a cheap oximeter from Walmart it works better than anything else. It's the type that clips over a finger it's fast and seems to be accurate. I'd like to get a wristband or watch that has a good SPO2 meter but nothing seems to exist.
The most painful thing I've experienced medically was an arterial blood draw to measure my o2 sat levels. (They numb your inner wrist with novocaine then go in with a giant needle to the artery deep in there. If it's that painful numb, I can't imagine what it'd be like otherwise.
And each time it was no more accurate than the pulse oximeter.
Most of the time we don’t numb patients to be honest. I’ve had it done to me, we practiced on each other in Med school. It is painful, but I suspect the Novocain you got didn’t work because it’s the artery that’s painful not the skin.
But it does give you different information than a pulse ox. For example, people can have respiratory failure from too low oxygen (captured on a pulse ox), but also from top high CO2 (not measured on pulse ox). It also gives a measure of acid-base status, which can be thrown off for a variety of reasons (usually renal or respiratory). It is used somewhat too much in my opinion but can be life saving in some situations.
An Pulse Ox and ABG are not interchangeable exams, with the ABG giving a lot more data about respiratory and metabolic derangements. A pulse ox can also be outright fooled such as in cases of carbon monoxide poisoning or essentially wrong in other poisoning. Also for a wrist ABG there’s no reason to use a giant needle. A 23g is usually fine, length is usually not an issue as the artery is actually quite superficial. For reference, an 18 gauge is the smallest that might be considered “large”. And the sizes are bigger as the number gets smaller.
Readit News
(for those who can't access the original site due to it being hugged to death)
The patients take their own measurements with a pulse oximeter and digital thermometer (both off the shelf consumer items). The person is prompted via SMS and submit their vitals via website. A software system orchestrates all of this and alerts patients and clinicians to anyone with worrying numbers.
This keeps beds free at the hospital, but still gets the small percentage of patients back to hospital that get really sick.
It also does all the other boring monitoring and administrative work needed when you're checking up on lots of real people.
Full disclosure. I worked on this project. A version has been open sourced and if you're a hospital or other medical service you're welcome to use our work. We're publishing improvements as we go. https://github.com/rmhcovid/txtmon
https://www.thermh.org.au/news/royal-melbourne-hospital-impl...
Using simple standalone devices and a low-coding platform already in use by hospitals (REDCap) the whole project was crash-built in a couple of weeks and is saving lives. That platform has many shortcomings (messier even than Excel), but there's various medical/privacy rules that make more traditional development unattractive for quickly prototyping. It's been a rewarding project to work on despite many frustrations.
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.
> 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
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."
"Takuo Aoyagi, a Japanese engineer whose pioneering work in the 1970s led to the modern pulse oximeter, a lifesaving device that clips on a finger and shows the level of oxygen in the blood and that has become a critical tool in the fight against the novel coronavirus, died on April 18 in Tokyo. He was 84."
[1] https://www.nytimes.com/2020/05/01/science/takuo-aoyagi-an-i...
[0]: https://www.youtube.com/watch?v=4pZZ5AEEmek
https://9to5mac.com/2020/03/08/apple-watch-blood-oxygen-satu...
At the time they reported that there were mentions of it in an iOS 14 leak, but it wasn't clear if it would be a software update to existing watches (somehow able to detect it with existing heartrate hardware) or in a watch hardware revision. Since it wasn't mentioned in the watchOS news at WWDC, looks like it'll be new hardware.
Either that or the code they found in iOS 14 was related to the health app and support for 3rd party oximiters, but that's not how the 9to5 post frames it so best I can do is take their word for it.
https://www.wearable-technologies.com/2020/01/fitbit-adds-bl...
Just bought a Huawei Honor 5 watch with pulse oximeter and heart rate functions: numbers seem correct and the device is fast: results in 5 seconds for O2 sat; almost instantaneous for HR.
Compare to Apple Watch HR function which takes at least 10 seconds to show result. Simultaneous side-by-side comparison of 2 devices: near identical numbers.
Even more impressive: Honor 5 costs $33 here: https://www.walmart.com/ip/HUAWEI-Honor-Band-5-Smart-Watch-B...
Superlight, compact, and comfortable. Huawei is no humbug!
My dad has COPD and IPF but he can't use the SPO2 meter on the Samsung phone I gave him (and Samsung disabled the SPO2 function for Canada). A Garmin VivoSmart 4 can't give a decent reading on him or me and it takes forever. Part of the problem is blood flow dad's fingers are ice cold due to his condition.
My dad uses a cheap oximeter from Walmart it works better than anything else. It's the type that clips over a finger it's fast and seems to be accurate. I'd like to get a wristband or watch that has a good SPO2 meter but nothing seems to exist.
And each time it was no more accurate than the pulse oximeter.
But it does give you different information than a pulse ox. For example, people can have respiratory failure from too low oxygen (captured on a pulse ox), but also from top high CO2 (not measured on pulse ox). It also gives a measure of acid-base status, which can be thrown off for a variety of reasons (usually renal or respiratory). It is used somewhat too much in my opinion but can be life saving in some situations.