Saturday, October 22, 2011

Cervicitis and PID

It has come to my attention that the tenuous grasp I thought that I had possessed about cervicitis and PID became archaic at some point. My beloved, and much highlighted, text that was new when I started med school is now behind the times.
It is so 2004...
To be fair, the 2000's have been active in this area, and I think that you should hear a little bit about what's been goin' on. 

First up: What are cervicitis and PID, i.e. what are the diagnostic criteria? This is important, because it turns out that in the ED we aren't so hot with the diagnosis of such things. Two studies point this out.
That's pus.
This study done in the Yale ED was written by your current boss (and with a future boss?), so you should probably know this! 
Hint!
The paper, "Compliance with the CDC Recommendations for the Diagnosis and Treatment of Sexually Transmitted Diseases" (Download here), published in 2004, documented how essential elements in the history and physical exam where missing from the charts of patients who had been diagnosed with cervicitis or PID. Furthermore, incomplete or erroneous treatment was often provided. All in an ED we all know and love...
More pus in dere (PID).
Another study, hot off the presses, make same case. (For download: Cervicitis in Adolescents: Do Clinicians Understand Diagnosis and Treatment?) Folks from the urology department at the U of Arkansas reviewed charts from both a primary care office and from a children's ED. All the records of adolescents who had received a diagnosis of cervicitis were analyzed for elements of the history, physical exam, and treatment. 

First off, about 25% of the patients diagnosed with cervicitis did not have documented physical findings that supported the diagnosis; i.e. they had neither a mucopurulent cervical discharge, nor a friable, easily bleeding cervix. Despite this over-diagnosis, they also found that 40% of the women who had been diagnosed with cervicitis actually had sufficient exam finding to meet PID criteria. So, they were also under-treating! Urgh. 

Even better, they break the results down according to the site of treatment: the adolescent clinic or the children's ED, and no one comes off looking good. The ED misdiagnosed about half the time, and the clinic about a third.

So, let's get the definitions laid out, so there is no confusion. This all comes from the current CDC guide for STDs, which you can access online, or you can download the pdf.

Cervicitis: 
"Two major diagnostic signs characterize cervicitis: 1) a purulent or mucopurulent endocervical exudate visible in the endocervical canal or on an endocervical swab specimen (commonly referred to as mucopurulent cervicitis or cervicitis) and 2) sustained endocervical bleeding easily induced by gentle passage of a cotton swab through the cervical os." 

PID:
"Empiric treatment for PID should be initiated in sexually active young women and other women at risk for STDs if they are experiencing pelvic or lower abdominal pain, if no cause for the illness other than PID can be identified, and if one or more of the following minimum criteria are present on pelvic examination:
  • cervical motion tenderness
    or
  • uterine tenderness
    or
  • adnexal tenderness."
They note that in cases where a diagnosis based on these minimal criteria "might cause unnecessary morbidity," that a few other elements may be used to boost the specificity, namely a mucopurulent discharge or a fever.
Telling this guy that his 14 y.o. daughter has PID = morbidity?
By contrast, the 1998 CDC guidelines required that all 3 of the minimal criteria (CMT, uterine, and adnexal tenderness) be found in order to make a diagnosis. Why did this change? After all, it's not so often that we change a diagnosis. Femur fractures, for example, have never had a revision of the diagnostic criteria!

Well, the PEACH trial happened. (Download here
This was a major randomized trial, and I simply will not do justice summarizing it here. Instead of reading any more mind-numbing studies about subarachnoids or PEs, read this. 

The trail was designed to examine the effectiveness of IV versus outpatient treatment of PID, but since they were collecting all this data on women with suspected PID, and then getting all these confirmatory tests, they wanted to see how sensitive and specific the elements of the CDC diagnostic criteria were. It was a multicenter trial, in both clinics and EDs throughout the US. Diagnostic techniques were comprehensive: PID was diagnosed histologically, from samples obtained from transcervical aspiration of endometrial tissue. In the end, they had complete information on 651 women, and the results were...
They found that the minimal CDC criteria (all 3 of CMT, adnexal, and uterine tenderness) was only 83% sensitive, with a specificity that wasn't exactly a selling point. Furthermore, if you were hoping that supporting elements, such as a fever (or it's absence) might help diagnosis, there were disappointing results.
For my part, the negative likelihood ratios for fever and purulent discharge grab my attention. The absence of the elements does not meaningfully help the diagnosis, since the negative LR is close to 1. Heck, even a negative NAAT test only cuts the probability in half!

In the discussion section, the authors offered their suggestion that "clinicians should consider empiric treatment of pelvic inflammatory disease in at-risk women with adnexal tenderness at presentation and no other obvious diagnosis," which is close to the current guidelines. And even with this incredibly liberal definition of PID, we are still going to miss about 5%!

So that's it for diagnosis. As for treatment, like all of ID, things change every year - look up the current reccs in the CDC guide I linked above. Some things are suprising (no more 125 of Rocephin!), and others stay the same (7 days of doxy for cervicitis, 14 for PID).This post is long enough, so I'll leave you with just one more cervix:
Bye!

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