The improvement of culture negative rate after changing the method of specimen collection in Pathum Thani Hospital

Mathaporn Subchalerm¹ , Khuanruan Wongsiri¹, Phrairach Phinphart¹, Siribha Changsirikulchai²

Pathum Thani Hospital¹ , Renal Division, Department of Medicine, Faculty of Medicine, Srinakharinwirot University²

Purpose: The report form Database of Peritoneal dialysis in Excel (DPEX) showed the peritonitis with culture negative rate in January to October, 2018 at Pathum Thani Hospital was 23 from 33 episodes (69.7%). The aim of this study is to report the improvement of culture negative rate after reviewing and changing the method of specimen collection in peritoneal dialysis (PD) patients who had peritonitis.

Method: In the past, the 20 ml of cloudy PD fluid (PDF) in bag which PD patients brought form home was collected, separated to 10 ml each and kept in 2 sterile bottles. These 2 bottles were sent to laboratory room for culture. Cefazolin and Ceftazidime were added in I exchange daily of 2 L PDF for 3 days while
waiting for result of culture. The method of specimen collection was changed during November 2018 to January 2019 as the follow; flush PDF 2 L, add 1 L of PDF in abdomen for 2 hours, collect 20 ml of drained PDF and separate 10 ml each with changed needles into 2 bottles of hemoculture (Bactec). The time from collected specimen to laboratory room for culture has to be within3 hours. The regimen of adding antibiotic into PDF is as same as those in previous protocol.

Result:There were 20 episodes of peritonitis which showed positive culture results in all cases. The culture negative rate was 90%. The culture no growth rate was 10%.

Conclusion: The culture negative rate at Pathum Thani Hospital was much improved after changing the method of specimen collection.