Hi everyone,

So as I said last week, I have been having trouble going through patient charts, and finding all the information I need to gather. The problem was that I was given certain laboratory results, co-morbidities, hospital complications, and medications to find, but sometimes I couldn’t find them. For example, there are about 8 different laboratory tests I was told to look for, and I was told I wouldn't find every single test result for each patient because doctors usually don't have to order that many laboratory tests to make a diagnosis. But, for some patients I will be able to find four or five tests and others I wont be able to find a single one. I thought I wasn’t able to find any laboratory tests because I wasn’t looking in the right places. So I would keep searching, but with no luck. It turns out, there are patients that don’t need any laboratory test done to diagnose an infection. 

This week I had help from an orthopedic physician assistant, Neil, who also does research with the MORE Foundation. He showed me how he goes through the charts and all the different places you can look for certain information. Initially, I was only looking at the documents labeled laboratory test for the results, but sometimes doctors put the test values in hospital consults. He also told me some patients won’t have laboratory tests done and to explain why he shared a link with me. To summarize, the link explained that there is no single set of diagnostic criteria for a periprosthetic joint infection (PJI), but MSIS (Musculoskeletal Infection Society) proposed that a PJI exists when:

1) There is a sinus tract communicating with the prosthesis; or
2) A pathogen is isolated by culture from at least two separate tissue or fluid samples obtained from the affected prosthetic joint; or
3) Four of the following six criteria exist:

a) Elevated serum erythrocyte sedimentation rate (ESR) and serum C-reactive protein (CRP) concentration,

b) Elevated synovial leukocyte count,

c) Elevated synovial neutrophil percentage (PMN%),

d) Presence of purulence in the affected joint,

e) Isolation of a microorganism in one culture of periprosthetic tissue or fluid, or

f) Greater than five neutrophils per high-power field in five high-power fields observed from histologic analysis of periprosthetic tissue at ×400 magnification.

This link was helpful because now I can understand what a doctor is thinking when looking at a possible infected knee. For example, in the case that their is a sinus tract communicating with a prosthesis, then no laboratory tests was needed to be ordered, which means I probably won’t find any. 

Now that Neil helped understand the charts a bit better, I’ll be starting back at patient one to make sure I didn’t leave out any important information form when I initially reviewed the charts. 

Thats all I have for today, thanks for sticking around, and see you next week!