QS, Ad Lib and PRN

Our hospital has a list of approved abbreviations. It is shorter than the list I had to memorize during my training. The reason some long-established abbreviations have been banned is their similarity to other abbreviations with different meaning. Even when doctors type orders instead of writing them by hand, the concern is that nurses and pharmacists may mistake them for something other than what the doctor ordered.

For this reason both QID (quater in die; four times a day) and QD (quaque die; once daily) are off the list; a hurried nurse or pharmacists could inadvertently quadruple a patient’s daily dose by imagining an “I” that wasn’t there to begin with.

At the local pharmacy, thanks to e-prescribing, we are forced into a specificity we weren’t tied to before:

Gone is the universal “QS”, (quantum sufficat; sufficient quantity), which made it the pharmacist’s responsibility to figure out how many pills it takes to do a prednisone taper with 6 pills the first two days, 5 the next two, then 4 a day for two days etcetera until zero.

“QS” also got us doctors off the hook with liquid medicines for children; while the printed “Monthly Prescribing Reference” listed the size bottles all the common antibiotics come in, the new e-prescribing software doesn’t tell us that. Consequently we have to prescribe the exact volume needed for a full course, hoping there is a bottle of just that size or that the pharmacist will be allowed to pick the closest size up without having to call us back.

“Ad Lib” (ad libitum; “freely as wanted”) has fallen by the wayside in medicine, and now seems mostly a term used in theater, public speaking or music.

Curiously, a theatrical synonym for ad libitum, extempore, was often used in my native Sweden for a custom prescription, usually for a cream or ointment, less often a hand-made capsule or pastille. In the United States, this term is seldom used, although the concept of specially compounded medications is not uncommon.

“PRN” (Pro Re Nata; “as the circumstance arises”) seems to have survived the abbreviation cutbacks. It allows the patient or caregiver to use the medication as needed.

Prescriptions were historically a vehicle for doctor-to-pharmacist communication that was written specifically to exclude the patient. This is to some extent why so many abbreviations were used. Somewhere near the bottom of most prescriptions typically was the word Label with a check box in front of it. Only when checked did the patient get to see the name of the medication on the bottle. That was before the era of informed consent, but the word and the check box can occasionally still be found on prescriptions.

Abbreviations and secret symbols still find their way into modern medical jargon and documentation, even if they are not allowed on prescriptions or in hospital records, from the handwritten Ψ for psychiatry or psychiatric to classics like GOMER – Get Out of My Emergency Room, ETKTM – every test known to man, and FF – Frequent Flyer, to some newer ones like:

PJAR – Person Just Ain’t Right

SALT – Same As Last Time

TMB – Too Many Birthdays, and

GOK – God Only Knows

Every profession needs its abbreviations…

4 Responses to “QS, Ad Lib and PRN”

  1. 1 Christina April 30, 2012 at 1:41 am

    Amusing post! Thanks for the laugh. It just goes to show that the standardized life required of the servants of our Machine Overlords JAR (Just Ain’t Right!)

    Thanks again for the laugh. Hope it helps you to know that some of these priceless abbreviations will not be totally gone… I pledge to take on a few for my records in my own practice of Chinese Medicine and Classical Homeopathy since my records are still my own TG (Thanks God/dess!)

  2. 4 Jewell Burke April 30, 2012 at 2:26 pm

    I’ll bet mine is POL poor old lady!

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