Also posted over at Rogue Medic (now at EMS Blogs).
-
This is adding to what I wrote yesterday about the continuing failure of Masimo’s RAD-57.[1] The RAD-57 does not demonstrate any kind of acceptable sensitivity or specificity to be marketed as a mass screening device – and especially not to screen firefighters to go back to fighting fire. This is just more evidence that the RAD-57 does not accurately measure carboxyhemoglobin (COHb).
Here is a report of a mass delusion that seems to have been compounded by the use of the Masimo RAD-57 non-invasive CO monitor. CO (Carbon monOxide) is a significant cause of poisoning in the US, but not relevant in this case. The RAD-57 incorrectly identified CO poisoning in half a dozen people who do not appear to have had any exposure to CO.
-
Sociogenic illness is a rare but well-described phenomenon. It involves a constellation of physical signs and symptoms without an organic cause in a group of individuals with a common ‘‘exposure’’ (1–8). It often occurs in the setting of large gatherings such as schools or when large numbers of people are living or working in close proximity.[2]
I wrote about a different example of mass delision a couple of weeks ago.[3] We underestimate our ability to delude ourselves, but we are great at self-delusion and we are most delusional in groups. No need for any objectivity. Just go with the feeling of a group.
-
Approximately 15 min into the mass, one child fainted, followed by another child. The children did not have any seizure activity and immediately awoke with normal mental status and were removed from the church. Within minutes, several more children reported a variety of complaints, including nausea, hand paresthesia, and dyspnea.[2]
A poison strong enough to cause people to pass out, is not going to result in a return to normal mental status right away.
-
The fire department initially evaluated the patients with complaints, including obtaining carboxyhemoglobin (COHb) oximetry and oxygen saturation readings from a hand-held portable Masimo® device (Masimo Corporation, Irvine, CA). At the scene, 6 patients were reported to have elevated COHb levels. As such, the church was closed and paramedics, as well as the city’s hazardous materials (HAZMAT) team, were called to the scene.[2]
If only someone had told them that the RAD-57 doesn’t work, much of the chaos could have been avoided.
-
-
Blood COHb levels, obtained in all patients soon after arrival in the ED, ranged from 0.2% to 1.2% (mean 0.65%). The hospital laboratory reference range for COHb is < 1.5% for non-smokers and as high as 5% for smokers. However, this upper value can be much higher in heavy smokers (9). None of our patients had elevated blood COHb levels.[2]
A magic diesel cure?
It’s a miracle!
-
In the ED, all patients had normal physical examinations, including neurologic and respiratory examinations.[2]
Were their physical exams much different on scene?
-
Subsequent evaluation of the church, classrooms, and surrounding premises by fire department and HAZMAT personnel found no evidence of carbon monoxide or any other toxicants.[2]
The interesting part that is not well described is the initial response of the fire department. Almost always, they have atmospheric CO alarms on their gear. When a firefighter walks into a room with elevated CO, the alarm goes off. When there is a report of a possible CO exposure, a couple of fully geared up firefighters will investigate everywhere they can in a building, looking for areas where CO might be leaking and for areas where CO might have accumulated.
There is no mention of any finding of CO at any time on scene.
No – the RAD-57 is not an indication of the presence of CO.
-
The affected persons were sitting in various areas of the church and many of the unaffected individuals were sitting near affected persons. This variability is not consistent with a simple asphyxiant. Furthermore, several patients became symptomatic after leaving the church, which would not be seen with a simple asphyxiant.[2]
Exposures to gasses should present with a predictable pattern. The people in the most heavily concentrated area should be the most affected, with the smallest people (generally children) and the most active people (also generally children) being more affected than the larger and less active people. That was not the case. This suggests MSI (Mass Sociogenic Illness, or mass delusion).
-
-
the escalation of symptoms and increased number of persons affected along with increasing fire and ambulance presence is a common phenomenon in MSI, referred to as ‘‘line of sight transmission.’’[2]
Even if it appears obvious that this is a mass delusion, we should provide treatment as appropriate for the symptoms presented. In this case, some oxygen is the only treatment indicated and the only treatment provided.
I wonder if this will lead to others reporting similar cases of mass delusions compounded by Magic 8 Ball RAD-57 readiongs.
-
See also –
Toxic exposure or mass sociogenic illness? The diagnosis can be challenging
The Poison Review
February 18, 2012, 12:28 am
Article
-
Mass psychogenic illness attributed to toxic exposure at a high school.
Jones TF, Craig AS, Hoy D, Gunter EW, Ashley DL, Barr DB, Brock JW, Schaffner W.
N Engl J Med. 2000 Jan 13;342(2):96-100.
PMID: 10631279 [PubMed - indexed for MEDLINE]
Free Full Text from N Engl J Med.
-
Footnotes:
-
[1] Accuracy of Noninvasive Multiwave Pulse Oximetry Compared With Carboxyhemoglobin From Blood Gas Analysis in Unselected Emergency Department Patients
Rogue Medic
Tue, 21 Feb 2012
Article
-
[2] Mass sociogenic illness initially reported as carbon monoxide poisoning.
Nordt SP, Minns A, Carstairs S, Kreshak A, Campbell C, Tomaszweski C, Hayden SR, Clark RF, Joshua A, Ly BT.
J Emerg Med. 2012 Feb;42(2):159-61. Epub 2011 Jun 11.
PMID: 21658882 [PubMed - in process]
-
[3] Mysterious Tics in Teen Girls – What Is Mass Psychogenic Illness – Part I
Rogue Medic
Tue, 07 Feb 2012
Article
.










We have the RAD-57, and I would agree that it’s a fairly unreliable device. I once put it on my finger to try it out on the way to a call, and it gave me a reading of 7%. I have never smoked a day in my life, and before getting on the ambulance, I had spent almost 4 hours doing station chores outside.
We started carrying those disposable one-time-use keychain CO detectors on our EMS first-in bags. Probably one of the best investments we’ve ever made.
Funny you should bring this up. A few months ago we were sent to a “possible CO leak” with mulitple patients. The only problem was the the FD got readings of 0 when they tested the air for CO. Which was confusing to say the least because the first unit on scene with a RAD 57 got a reading of 18 ppm on an elderly gentleman who had some dypnea and chest pain.
The supervisor was convinced that the FD didn’t know what they were doing because of the RAD 57 readings.
We arrived about 10 minutes into the debacle and were assigned to transport the elderly male. At this point he was pain free and the ECG was unremarkable. I placed the probe from our RAD57 on his finger and placedthe SpO2 probe from our cardiac monitor on another finger. The SpO2 readings were identical, so I worked on the assumption that the RAD57 was accurate in so far as that went. I then switched to CO reading and got 0 ppm. I was a bit skeptical about the original reading since the FD was still getting 0 ppm inside the building and there was no discernible failure of the furnace. Nor were the CO detectors in the building sounding.
I advised the supervisor to recheck all of the patients with a different RAD57, but he declined my advice.
In the end it turned out that someone had used pepper spray in the bulding and it had gotten into the ventilation system.
Another oddity of the RAD57 is that it more than 50% of the time it will not read my SpO2. I test is several times a week and much of the time it just won’t read my SpO2. I put it on another person and it works fine.
I don’t have much faith in the device any more, but no one in management seems to be concerned about the issues I’ve raised.