Temporal Changes in the Relationship Between Central Venous Pressure and B-Line Score in Patients Undergoing Transurethral Resection of the Prostate: Evidence from a Generalized Estimating Equations Model

Objective: To investigate the correlation between central venous pressure (CVP) and B-line score through dynamic monitoring of the two parameters in patients undergoing transurethral resection of the prostate. Methods: A total of 101 patients who underwent transurethral resection of the prostate were enrolled, with the procedure performed under general anesthesia. B-line score (quantified via transthoracic lung ultrasound), CVP, peak airway pressure (Ppeak), and arterial blood gas parameters, including arterial sodium (Na⁺) and potassium (K⁺) concentrations, hemoglobin (Hb), and PaO₂/FiO₂ ratio, were measured at the following time points: skin incision (baseline, T0), and with irrigation fluid volumes of 5000 mL (T1), 10,000 mL (T2), 15,000 mL (T3), and 20,000 mL (T4). Results: Data were analyzed using a generalized estimating equations model. CVP showed a significant positive correlation with the B-line score (β = 0.449, P < 0.001). With the increase in irrigation fluid volume, there was a significant increase in the B-line score at T2, T3, and T4 (T2: β = 0.785, P = 0.003; T3: β = 1.985, P < 0.001; T4: β = 3.000, P < 0.001). However, the main effect of CVP on the B-line score was not significant (β = 0.077, P = 0.148), and its effect did not show significant changes over time (T1: β = -0.008, P = 0.689; T2: β = 0.017, P = 0.783; T3: β = -0.040, P = 0.559; T4: β = -0.048, P = 0.474). The B-line score's predictive value based on CVP was initially weak at T0 and T1 but significantly increased at T2, T3, and T4, with a corresponding rise in the B-line score. Conclusions: B-line scores increased significantly over time during TURP and were closely associated with multiple physiological parameters. Although CVP was generally positively correlated with B-line scores, its effect varied across different time points, suggesting a time-dependent predictive value of CVP for pulmonary fluid status. Trial registration ChiCTR2200065753, 14/11/2022, Title: “Application of transthoracic lung ultrasound in patients undergoing prostatectomy”. Website: https://www.chictr.ogr.cn.