#4858 THE CHANGES OF THE C REACTIVE PROTEIN LEVEL DURING THE CRRT PROCEDURE
Authors: Majstorovic Gordana Strazmester , Azasevac Tijana , Markovic Mira , Knezevic Violeta , Petrovic Lada 
Published: June 2023

Abstract

Background and Aims
Continuous renal replacement therapy (CRRT) is recommended for critically ill patients (pts). Various infections and sepsis often occur in these pts. In addition to being frequently used as inflammation parameter, C reactive protein (CRP) is considered an important regulator of inflammatory processes and may have an active role in atherosclerosis. Changes in its level can have indirect effects on these processes. The aim of this study was to monitor change of CRP level during the CRRT procedure and to evaluate the potential correlation between this change and other monitored parameters.

Method
The study was done as the observational, retrospectively prospective study on 154 pts, on whom 343 CRRT procedures (proc) were performed. All pts were treated at the Clinics of the University Clinical Centre of Vojvodina, by the Dialysis Department, during 2021. and 2022. Procedures that lasted longer than 5 hours were included. CRRT modalities were CVVHD and CVVHDF, with the use of different filters (EMiC2, Kit8/CiCa1000, oXiris, ST150), according to the device (MultiFiltrate, PrismaFlex) and anticoagulation used. Demographic, clinical and CRRT proc data were collected from the medical documentation. Blood for laboratory testing was sampled at the beginning and the end of the proc. An increase or decrease of CRP level by more than 5% compared to the initial value was considered significant. The collected data were statistically processed.

Results
From 154 pts, 86.83% were men, 13.17% women, with average (avg.) age of 56.52 years. From 343 proc, 41.69% were CVVHD, 58.31% CVVHDF, with avg. duration of 1033 min. Average ultrafiltration (UF) was 2670mL, with avg. UF/hour of 161.54mL/h. Average initial CRP level was 176.25mg/l, with avg. level of 174.6mg/l at the end of the proc. In 44.9% proc an increase and in 43.44% proc a decrease in the CRP level was verified. The CRP level did not change significantly during 11.66% proc (40/343). Patients' age (p = 868) and gender (p = 752) did not affect the change in CRP level during CRRT proc. Procedures in which CRP level decreased lasted longer (1084min) than those with CRP level increase (1023min), but the difference is not statistically significant (p = 199). Prescribed CRRT dose (p = 485), nor total UF (p = 164) did not affect change in CRP level during proc. Hourly UF was significantly lower for CRRT proc during which CRP level decreased (148.18mL/h) compared to those with the CRP level increase (172.23mL/h) (p = 000). CRRT modality had a significant impact on changes of CRP level during the proc. In a higher percentage of CVVHD proc (48.32%) a decrease in CRP level was seen compared to CVVHDF proc (36.36%) (p = 035). A significant difference was found in the changes of CRP levels in relation to the filters used (p = 011). The use of the EMiC2 filter most often resulted in a decrease in CRP level (56.25%), compared to the use of other filters. Septic condition was present in 85.91% of proc that ended with a decrease of CRP level and in 66.23% of proc with the CRP level increase (p = 000). In proc with the CRP level decrease, basal levels of PCT and fibrinogen were significantly higher than in those with the CRP level increase (p = 037, p = 000 retrospectively). Initial number of WBC did not differ between two groups (p = 424). Comorbidities such as diabetes (p = 489), malignancy (p = 5) or autoimmune disease (p = 25) did not affect change in CRP level during CRRT proc, nor did surgery precede the proc (p = 782). No association between the changes of CRP level during the CRRT proc and the subsequent pts mortality (p = 289) or recovery of renal function (p = 808) was found.

Conclusion
During the CRRT procedure, the level of CRP in significantly influenced by the average hourly ultrafiltration, the CRRT modality, the filter used, and the presence of septic condition, with high levels of PCT and fibrinogen.