Positive Dialysate Gram Stain Predicts Outcome of Empirical Antibiotic Therapy for Peritoneal Dialysis‐associated Peritonitis

Abstract

Empirical antibiotic treatment with a first-generation cephalosporin plus gentamicin for peritoneal dialysis (PD)-associated peritonitis before culture results are available is still wildly used due to concerns regarding the economic burden and antibiotic-resistant bacterial infections. The aim of this study is to define the factors that predict the outcome of empirical antibiotic therapy for PD peritonitis. This is a retrospective study of patients with PD peritonitis over the last 10 years. Patients who had been treated empirically with intermittent intraperitoneal first-generation cephalosporin and gentamicin were enrolled. Eighty-three patients had 192 episodes of PD peritonitis. In total, 159 peritonitis episodes were treated with intraperitoneal antibiotics combined with first-generation cephalosporin and gentamicin empirically. Twenty-five peritonitis episodes had no pathogens identified by dialysate culture. In total, 122 (122/159, 76.7%) PD peritonitis episodes were caused by bacteria, 9 (9/159, 5.7%) were fungal, and 3 (3/159, 1.9%) were Mycobacterium tuberculosis peritonitis. Sixty-four (64/159, 40.3%) peritonitis episodes were successfully cured by empirical intraperitoneal antibiotic therapy. Empirical antibiotic treatment failed in 95 episodes (95/159, 59.7%). The positive rates of dialysate Gram stain in the empirical treatment success and failure groups were 15.6% and 40.0%, respectively (P = 0.001). The odds ratio of empirical treatment failure with a positive bacteria Gram stain was 3.60 (95% CI: 1.65-7.82). The dialysate Gram staining result was a significant predictor of empirical antibiotics treatment outcome for PD-associated peritonitis. Therefore, using an empirical antibiotic regimen for patients with an initial positive bacterial Gram stain of the dialysate should be introduced cautiously.

ISPD peritonitis guideline recommendations: 2022 update on prevention and treatment

“…Gram stain of the PD effluent should be performed even though the result is often negative. 137,138 An additional benefit of Gram stain is its effectiveness in early detection of fungal elements, facilitating timely diagnosis and management of fungal peritonitis. 139 The diagnostic yield of the Gram stain is increased if it is performed on a centrifuged specimen.…”

ISPD Peritonitis Recommendations: 2016 Update on Prevention and Treatment

“…Gram stain of the PD effluent should be performed even though the result is often negative ( 209 ). The yield on the Gram stain is increased if it is performed on centrifuged specimens.…”

Peritoneal Dialysis Guidelines 2019 Part 1 (Position paper of the Japanese Society for Dialysis Therapy)

“…Depending on the pathogen identified, it can also indicate specific infection sources. Gram staining of PD effluent often yields a negative result, but it should still be conducted considering its contribution to early-stage antibacterial drug selection and administration if it turns out positive [429]. Gram staining positivity increases by a factor of 5 to 10 by conducting centrifugal separation for 15 min with 50 mL of dialysis effluent at 3000g, suspending with 3-5 mL of physiological saline solution, and planting them in a solid medium or standard blood medium afterwards [430].…”