Intraoperative B-line scores increase over time and are minimally affected by central venous pressure during transurethral resection of the prostate

To investigate temporal changes in the relationship between central venous pressure (CVP) and B-line scores through dynamic monitoring of the two parameters in patients undergoing transurethral resection of the prostate (TURP). A total of 101 patients who underwent TURP were enrolled in the study, with the procedure being performed under general anesthesia. B-line scores (quantified via transthoracic lung ultrasound), CVP, PaO₂/FiO₂ ratio, hemoglobin (Hb), peak airway pressure (Ppeak), arterial sodium (Na⁺), and potassium (K⁺) concentrations were measured at the following time points: baseline at the start of surgery (T0) and upon irrigation fluid volumes of 5000 mL (T1), 10,000 mL (T2), 15,000 mL (T3), and 20,000 mL (T4). Generalized additive mixed models (GAMMs) were used to analyze the longitudinal data. In the longitudinal study of 101 patients undergoing TURP, 90 were included in the final analysis. Poisson GAMM analyses revealed a significant time effect on B-line scores (F = 62.029-69.486, P < 0.001 across models), showing progressive increases from T0 to T4. CVP demonstrated a modest main effect (F = 3.156-4.026, P = 0.045-0.076) and a non-significant interaction with time (F = 1.441-1.967, P = 0.161-0.231), persisting after adjustments for age, weight, height, effective tidal volume, and intraoperative use of furosemide (adjusted pseudo-R² = 0.553). Quantitative and percentile analyses showed only small and uncertain associations between CVP and B-line scores, with confidence intervals consistently crossing the null. Across multiple sensitivity analyses, the estimated CVP effect remained minimal and statistically non-significant regardless of modeling approach. B-line scores increased progressively during TURP, whereas the association between CVP and B-line scores remained small and statistically non-significant across all analyses. These findings suggest that intraoperative B-line dynamics primarily reflect temporal changes rather than CVP fluctuations.Trial registrationThe trial registration number: ChiCTR2200065753, 14/11/2022. Title: "Application of transthoracic lung ultrasound in patients undergoing prostatectomy". Website: https://www.chictr.ogr.cn .