Accuracy of rectal temps

The argument for accuracy today just doesn’t cut it. I don’t think there are that many situations medically where the precise temperature distinction between oral, rectal, tympanic axillary etc. can make that much of a difference. In the days of glass thermometers when safety was an issue I think that pushed people towards the RT. The accuracy argument in my opinion is just an excuse to take someone’s temp.

I've often heard the expression, : "The gold standard" when the discussion of temperature taking (measurement) and type thermometer used. Route of measurement for accuracy, preferably rectally, and a glass mercury thermometer is often believed to be more accurate when used rectally than other thermometers out there. One more small item...the glass rectal thermometer bulb (usually pear/teardrop shaped)-designed to protect the rectum when inserted.)

A thermometer has the same accuracy regardless of which hole you stick it in. The question is whether you have the intelligence to use the reading you get.

I had several rectal temps growing up . i was told that they are more accurate. when i got to be at like 7 or 8 my mom told me to lie down and i had to insert it in myself. because of that i not only know that it is the accurate way, but i know now that i have developed a fetish for it as well.

Oh I'd say the discussion is over regarding accuracy. Just about any legitimate health care giver agrees that RT is most accurate. The question often then is how important is accuracy? If oral or ear or forehead will determine fever, is degree of accuracy really important? Probably not.

I think it all depends on the reason for taking or monitoring someone's temperature. In a clinical environment like ITU accuracy is vitally important , especially with immunocompromised patients. The quicker you can detect and treat an infection , the better the chance for surviving. That's why we have continuous temperature monitoring, we prefer the rectal route and use a rectal temperature probe; with the advent of urinary catheters with a temperature monitoring port we now also use these.

As with all things. temperature is only one aspect that we use , we also include things like , WBC, CRP, ESR, haematocrit when determining if the patient has an infection or not.

RN

My mother used to justify the systematic use of rectal temperatures in the household by reliability as opposed to oral temperatures. They were also used in hospitals for that reason, I think.

I think it may have been right when glass thermometers were used, particularly for children, because one had to hold the thermometer under the tongue for several minutes if I understand correctly.

A thermometer has the same accuracy regardless of which hole you stick it in. The question is whether you have the intelligence to use the reading you get.

That's incorrect. I can point you toward several recent studies regarding the accuracy of various measuring methods:

this one compared ER rectal temps over a 10-year perios

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4129836/

and this one concluded that:

CONCLUSION:

The oral and tympanic temperature readings are not equivalent to rectal thermometry readings. Oral thermometry frequently underestimates the temperature relative to rectal readings, and TM values can either under- or overestimate the rectal temperature. The clinician needs to be aware of the varying relationship between oral, TM, and rectal temperatures when interpreting readings.

https://www.ncbi.nlm.nih.gov/pubmed/22224147

I had several occasions where my oral temp was more than 1°C lower than the rectal temp which I had afterwards to have an accurate reading...

Most moms with common sense can usually tell when a kid/teenager, husband, etc., has a fever and whether it even warrants taking a temperature, much less a rectal. On occasion through the years with my husband and the girls, I rarely took rectal temps and only if they were running an elevated fever in cases of nausea/vomiting, coughing, serious flu, when I felt it was the best route to get a good reading, period. One degree here or there I wasn't that concerned about. However, I remember lying in bed my mother used to ask me, "Can you keep this under your tongue and breathe through your nose?" If I couldn't, she turned me over and took it in my behind. She was a stickler for accuracy.

@Vicki V....When I was age 9 my mom poked me under my tongue with the thermometer and told me if I did not do it right, she was going to take it rectally and that caused a big fuse and when I told her that I can do it better alone, she hushed and I also told her that rectal temperatures are for infant and toddlers.

We realised that taking temperature under the arms is not really accurate, so we Change to RT.

I'd say yes. It's the only way I go

It reflects the actual core temperature

Mom always thought that rectal was more accurate. On the other hand, I wasn't given the choice for oral.

Since rectal temps aren't used by healthcare providers, my guess is that the accuracy difference is not critical. When I was a kid during the 60's, some parents and doctors insisted on taking rectal temps, even on teens. I'm not convinced that it was necessary in most cases. I was lucky to have been spared from it.

Rectal temperatures are definitely the most accurate but i think oral and even under the arm are accurate enough for most cases especially at home. I work in a doctors office and i would say the two nurses use the rectal thermometer here maybe a handful of times a day. We do in the ear or under the arm.

It is definitely more accurate.

When I was a young boy, I was always told my rectal temperature was way more accurate. In my family we only had rectal thermometers and to the age of 10, my parents inserted the thermometer in my rectum to check if I had a fever. At the age of 11 I was teached by my mom how to take my temp rectally by myself, so even when I was a teenager I always needed to take my temperature rectally...

There is no doubt rectal is the most accurate way to take a temperature. However in a true medical setting sadly it seems the rectal thermometer is a rare thing these days.

I have never done a test but doctor's say it is. If a female doctor wants to compare or female nurse i am game: )

Rectal temps are more accurate than oral, armpit, or tympanic. If accuracy is that important to you, then have them put a probe in a vein or stick a probe in your liver. Better is the enemy of good enough. For all practical purposes, a rectal temp isn't necessary unless it is to pleasure yourself, which is OK.

If a rectal temp is 1-1.5 degrees more accurate than oral - does it change your diagnosis or course of treatment?? There are a lot of medical experts here where that might be meaningful - but for most of us poor slobs what difference does it make?? Even for the medical pros.....

Of course

It is the most accurate technique, regardless of opinion.

If you visit an emergency room, and infection is suspected, they need exact measurements and they want them now.

They'll start with oral and if it appears high they'll roll you on your side and insert the probe with little to no warning.

ERs by far aren't erotic places but if you manage to survive your emergency the memories can be highly erotic.

Emergency rooms are intense places and are preferred duties for medical professionals. It's also where accuracy is required, and your dignity gets checked at the door.

Would you say rectal temps are more accurate than taking them through the mouth?

Yes, but 99% of the time rectal is NOT needed.

They will only do rectal if they suspect you are in bad shape

Yesterday was feeling like complete crap. I usually don’t take rectal temperatures on myself - so I checked orally... 99.1. A little high for me but nothing worth writing home about. But with lots heat coming off my head and neck, I didn’t trust the reading. So I checked under the arm. That came it at 99.0. Besides being so surprised at the negligible difference between oral and axillary, it still seemed lower than I felt.

Soooooo.... out came the kids’ old thermometer and the Vaseline. When it beeped 20 seconds later, I was cooking at 101.9.

I dragged myself to urgent care - told them of my symptoms (it really seemed like the flu at the time). Oral temp in the office was 98.7. They said “no fever.” I told them how I checked it at home. OMFG - the looks I got from the nurse and the PA. They actually said “if you think you can come in here and get us to take a rectal just so you can fulfill some sick fantasy, you can just leave.”

I asked to see the doctor in charge. She started to give me the same song and dance. And then she felt my head and neck and did a double... make that a triple take. I was clearly burning up.

She went and got the one rectal thermometer in the office that is used almost exclusively on babies, and had me lie down. Ended up checking twice. When the first reading was 102.6, she wanted to reconfirm. Second was 102.8. They then did another oral and it was 98.9, axillary was 98.4.

They said the oral for some people is artificially low but axillary, while not precise, should’ve been at least directionally predictive (i.e., over 100 in my case).

The parting comment from the lead doctor to the others was “rectal doesn’t lie.”

BTW the flu test was negative.

Rectal is the most accurate, and also the most erotic, if done outside of a clinical setting. In the majority of cases, an oral temp. will work just fine, and is the preference of most adults, to my knowledge. To most of us on this forum, they don't know what pleasures they're missing out on.

Never seen or heard of a mouth temperature in my parents' house. Every one took his rectal temperature.

Rectal temps are more accurate but as Susie says really not needed to be that accurate. I remember back in the day my mom talking about a girl down the street trying to conceive, and she mentioned she did a rectal temp every morning to zero in on when she was ovulating. This made a teenage boy sit up and pay attention. I don't remember if it worked but I also know people use it for birth control as well, although that seems pretty chancy to me.

I don't remember if it worked but I also know people use it for birth control as well, although that seems pretty chancy to me.

I have a niece who chose that method for birth control. It's inaccuracy is how she and her husband got baby number three.