When we test for Peritonitis, we usually have the patient put in a liter or two, or the patient comes to our clinic and we put it in. I know the recommendation is to put it in for 1-2 hours. My question is; can you test the PD fluid if it's been in there longer? 3 hours, 4 hours longer? will it change the test for cell count and culture?

We thank you for your question. From the latest ISPD peritonitis guideline recommendations, PD fluid should have dwelled in the patient’s peritoneum for a minimum of 2 hours before collection for cell count and culture. To address your specific question, it is not a concern if the PD fluid has dwelled in the patient’s abdomen for more than 2 hours, only if it has dwelled for less than 2 hours. (1,2)
 
1.Li PK, Chow KM, Cho Y, Fan S, Figueiredo AE, Harris T, Kanjanabuch T, Kim YL, Madero M, Malyszko J, Mehrotra R. ISPD peritonitis guideline recommendations: 2022 update on prevention and treatment. Peritoneal dialysis international. 2022 Mar;42(2):110-53. Available at: https://journals.sagepub.com/doi/10.1177/08968608221080586
 
2.Figueiredo AE, Bowes E, Chow JS, Hurst H, Neumann JL, Walker R, Brunier G. PD effluent specimen collection: Your questions answered. Peritoneal Dialysis International. 2023 Nov;43(6):442-7.