Objectives To understand the natural course of infection complications in elderly patients with tunnel-cuffed catheter (TCC) blood purification; and analyze the prognostic significance of blood routine test parameters detected before catheterization. Methods Collect 2430 patients who underwent blood purification treatment at the First Medical Center of the Chinese PLA General Hospital from January 2008 to January 2023, and follow up the patients who used TCC and had blood routine tests 24 hours before catheterization. Analyze the natural course of infection complications after TCC; Using all-cause death as the endpoint, Kendall correlation analysis was used to investigate the relationship between clinical data of first infection after TCC and prognosis. The nested case-control study was used to match the case group with the control group according to the ratio of hypertension and diabetes 1:1. The first infection within 6 months of TCC was taken as case group (n=34), and the first infection after 6 months of TCC was taken as control group (n=34). The risk factors related to the first infection within 6 months of TCC were analyzed by logistic regression. Validate the results of nested case-control studies across the entire group of patients and analyze the value of mean platelet volume (MPV) before catheterization in predicting the prognosis of first-time infections. Results A total of 77 patients were followed up, aged (78.4±7.3) years, with a median follow-up time of 28.0(13.8-70.5) months. After the first infection, 32 died and 45 survived. Compared with first-time infected survivors, deceased patients had a higher age and lower catheter age (P<0.05). The first infection within 6 months of TCC is positively correlated with death (r=0.336, P=0.003), and the cumulative survival rate is significantly lower than that in infected patients after 6 months of TCC (P<0.001). The results of a nested case-control study showed that the MPV of infected group within 6 months of TCC was significantly higher than that in control group [(10.64±1.05) fl vs. (9.89±0.80) fl, P=0.001]. Logistic regression analysis showed that the risk of infection was 3.222 times higher in high MPV group compared with control group. In the entire group of 77 cases, it was confirmed that high MPV values were associated with the occurrence of first infection within 6 months of TCC (P=0.037). Conclusions First infection within 6 months after TCC catheterization is associated with death; Patients with high MPV values before catheterization have a significantly increased risk of first infection within 6 months after TCC. The MPV level before catheterization may indicate a poor prognosis for infected individuals after TCC, and this indicator may be a personalized decision-making reference for TCC.