11 - Platelet Decreases During Continuous Kidney Replacement Therapy Initiation and Outcomes: Analysis of the Worldwide Exploration of Renal Replacement Outcomes Collaborative in Kidney Disease (WE-ROCK)

Poster Number: 11
Publication Number: 11.107

Abby M. Basalely, Cohen Children's Medical Center, West Hempstead, NY, United States; Natalja L. Stanski, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States; Dana Fuhrman, UPMC Childrens Hospital of Pittsburgh, Pittsburgh, PA, United States; JANGDONG SEO, Cincinnati Children's Hospital, Bloomington, IN, United States; Nicholas Ollberding, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States; Katja M. Gist, Children's Hospital Medical Center (Cincinnati), Cincinnati, OH, United States; Shina Menon, University of Washington School of Medicine, Seattle, WA, United States

Background: Thrombocytopenia is common in critically ill patients, and data suggest the initiation of  CKRT further may decrease platelets. A study of CKRT in adults demonstrated that platelet nadir < 100 × 10^3/µL 7 days post CKRT initiation was associated with increased risk of mortality. However the risk factors and associations of thrombocytopenia after CKRT initiation in children are unknown.

Objective: (1) Determine risk factors for thrombocytopenia post CKRT initiation (2) Evaluate association of platelet nadir of < 100x10^3 /µL (100) by 72 hours(h) of CKRT with mortality

Design/Methods: The WE-ROCK study is a retrospective international multicenter study (32 centers, 7 nations) of patients aged 0-25 years treated with CKRT for Acute Kidney Injury or Fluid Overload (FO) from 2018-2021. For this analysis, patients with chronic thrombocytopenia, hematologic malignancy, atypical hemolytic uremic syndrome, or thrombotic thrombocytopenic purpura were excluded. The exposure variable was nadir platelet value within 72h of CKRT initiation categorized by >  or < 100. The primary outcome was survival to ICU discharge.

Results: 831 patients, 685(82%) had nadir platelets <100 within 72h. This was associated with lower median age, higher severity of illness scores, and higher sepsis rates and percent FO at CKRT initiation (Table 1). CKRT characteristics associated with nadir platelets < 100 were smaller catheter sizes, higher CKRT dose/kg, and blood flow rate (BFR)/kg.  Platelets counts prior to CKRT were significantly lower in those with nadir platelets <100 vs ithose who had a nadir > 100; median (IQR)  49 (24, 91) vs 241 (170, 358) . Plasma exchange during CKRT was done in 134(20%) patients with platelets < 100 compared to 15 (10%) of those with platelets > 100 (p=0.008). Survival to ICU discharge was lower in patients with a nadir < 100 but was not significant on multivariate analysis.

Conclusion(s): This is the largest study to evaluate risk factors and outcomes of thrombocytopenia after CKRT initiation in pediatric patients. Unadjusted analysis suggests that younger patients are at greater risk of platelet decrease than their older, larger counterparts. Platelet nadir <100 at 72 hours post CKRT initiation was associated with greater illness severity and sepsis at CKRT initiation and may be related to baseline thrombocytopenia. Interestingly smaller catheters, higher BFR/kg and larger CKRT doses were associated with platelets <100 at 72h. This may be due to mechanical shearing forces and/or inflammation. Additional analyses are needed to evaluate change in platelets from baseline to better predict outcome.