Effects of colloid versus crystalloid priming on early haemodynamics in critically ill patients receiving CRRT: protocol for a randomised controlled trial.

introductionDespite the acknowledged advantage of continuous renal replacement therapy (CRRT) in maintaining stable haemodynamics compared with intermittent haemodialysis, hypotension remains a common complication, affecting up to 43% of patients immediately following CRRT. This issue can precipitate serious adverse events and is associated with increased mortality. The significant reduction in blood volume during the withdrawal process for machine processing, combined with the rapid elimination of urea during purification, can cause a precipitous decline in plasma osmotic pressure, both of which may serve as triggers for early hypotension during CRRT. Currently, conventional strategies, such as priming the pipeline with normal saline combined with double connections, have failed to significantly reduce the incidence of early hypotension. To prevent this complication, some researchers have turned to the use of human albumin, plasma and colloid fluids instead of normal saline for pipeline priming. Nevertheless, evidence favouring this approach over traditional crystalloid priming is still lacking. This study aims to investigate whether colloid priming is superior to crystalloid priming in reducing the incidence of early hypotension and all-cause mortality, as well as shortening the duration of hospitalisation in intensive care unit and reducing the dialysis dependence in critically ill patients undergoing CRRT. METHODS AND ANALYSIS: A single-centre, prospective, randomised controlled trial will be conducted at West China Hospital of Sichuan University, China. A total of 216 participants who met the inclusion and exclusion criteria will be recruited and divided into either the experimental or control group at a ratio of 1:1 via a central randomisation system. In the experimental group, succinyl gelatin will be used to prime the pipeline prior to the connection with the CRRT machine, whereas the control group will use normal saline. The primary outcome is the incidence of early hypotension during CRRT. The outcome assessors and data analysts will be blinded. All the data will be analysed based on randomly assigned groups unless data for the primary outcomes are missing. ETHICS AND DISSEMINATION: The trial protocol was approved by the Ethics Review Committee of West China Hospital of Sichuan University (2023.2084), and the results will be published in peer-reviewed journals. TRIAL REGISTRATION NUMBER: ChiCTR2400082835.