[Research on the changing trends of filter inlet pressure and extracorporeal circuit coagulation degree in patients with sepsis-induced coagulopathy undergoing continuous renal replacement therapy].

OBJECTIVE

To investigate the changing trends and clinical significance of filter inlet pressure and extracorporeal circuit coagulation degree within 12 hours before unplanned discontinuation of continuous renal replacement therapy (CRRT) in patients with sepsis-induced coagulopathy (SIC).

METHODS

A prospective nested case-control study was conducted. A research team was established, and SIC patients undergoing CRRT in the Emergency Intensive Care Unit of Qingdao Municipal Hospital from December 2024 to September 2025 were enrolled by convenient sampling. Demographic data were collected, laboratory parameters were measured before CRRT initiation, observational indicators during CRRT were recorded, and filter inlet pressure and extracorporeal circuit coagulation degree were determined at the start of CRRT and during treatment. Patients were divided into a case group and a control group according to the occurrence of unplanned discontinuation. The changing trends and intergroup differences in filter inlet pressure and coagulation degree within 12 hours before discontinuation were analyzed between the two groups. The risk of unplanned discontinuation was categorized into low-risk group (pressure curve elevation angle≤30degree angle), medium-risk group (30degree angle<pressure curve elevation angle<60degree angle), and high-risk group (60degree angle≤pressure curve elevation angle<90degree angle). Multivariate ordinal Logistic regression was used to analyze the effects of filter inlet pressure and coagulation degree at different time points on the risk of unplanned discontinuation. Receiver operator characteristic curve (ROC curve) analysis was performed to evaluate their predictive value for 60degree angle≤pressure curve elevation angle<90degree angle.

RESULTS

Finally, 78 patients were included in the case group and 121 in the control group. At 12, 8, 4, 2, and 0.5 hours before discontinuation, both filter inlet pressure and coagulation degree showed an upward trend in both groups, with higher values in the case group than in the control group [filter inlet pressure (mmHg, 1 mmHg=0.133 kPa): 122.31±22.00 vs. 104.17±9.94 at 12 hours before discontinuation, 174.55±16.62 vs. 158.89±6.85 at 0.5 hours before discontinuation; coagulation degree: (14.19±3.51)% vs. (9.48±4.80)% at 12 hours before discontinuation, (64.61±6.15)% vs. (51.08±4.80)% at 0.5 hours before discontinuation; all P<0.05]. The impact of filter inlet pressure on unplanned discontinuation increased over time. The probability of unplanned discontinuation in the high-risk group was 1.076 times that in the low-risk group at 12 hours before discontinuation [odds ratio (OR)=1.076, 95% confidence interval (95%CI) was 1.036-1.118, P<0.001], which gradually rose to 1.217 times at 0.5 hours before discontinuation (OR=1.217, 95%CI was 1.086-1.284, P<0.001). Similarly, the influence of coagulation degree on unplanned discontinuation increased over time, with the probability in the high-risk group being 1.434 times that in the low-risk group at 12 hours before discontinuation (OR=1.434, 95%CI was 1.123-1.830, P=0.004) and rising to 7.954 times at 0.5 hours before discontinuation (OR=7.954, 95%CI was 3.212-19.697, P<0.001). ROC curve analysis showed that coagulation degree at 12 hours before unplanned discontinuation had the best predictive performance for 60degree angle≤pressure curve elevation angle<90degree angle in SIC patients, with an area under the curve of 0.879, a sensitivity of 0.793, and a specificity of 0.859 when the optimal cut-off value was 14.80%.

CONCLUSIONS

During CRRT in SIC patients, both filter inlet pressure and coagulation degree increase over time, and their impacts on unplanned discontinuation are time-dependent. Increased extracorporeal circuit coagulation within 12 hours before unplanned discontinuation exerts a greater effect on unplanned discontinuation than elevated filter inlet pressure. Coagulation degree is superior to filter inlet pressure in predicting unplanned discontinuation with 60degree angle≤pressure curve elevation angle<90degree angle. A coagulation degree of 14.80% should alert clinicians to a high risk of unplanned CRRT discontinuation within 12 hours.