4. Discussion
coma, perioral numbness, catheter occlusion, blood coagulation
BACTERIAL RESISTANCE, COMA
A pioneering pragmatic randomized controlled trial has been designed to compare the effects of 10 U/mL heparin saline and 4% sodium citrate as locking solutions for CVCs (excluding dialysis catheters).After using heparin to lock the tube, it will affect the four indexes of blood coagulation, resulting in elevated APTT (LSMD = 0.86, 95%CI 0.12 to 1.61, In patients infused with CVCs, catheter occlusion rate using heparin-locking solutions has been estimated in the range of 0% to 33% [Theoretically, the use of sodium citrate as a tube locking solution can reduce the CRBSI rate because metal ions play a key role in stabilizing the extracellular matrix of microbial biofilms, in which sodium citrate exhibits antibacterial activity by depriving microorganisms of these essential metal ions without worrying about bacterial resistance [Regarding safety, because most of our patients are in a state of sedation and analgesia or coma, it is impossible to ask the patients about their perioral numbness. Fortunately, ionized calcium is monitored, finding that the rate of ionized calcium < 1.0 mmol/L in the heparin group and the sodium citrate group is similar (We have to acknowledge some limitations to our study. The study is conducted in a tertiary hospital with a dedicated team of physicians and an intravenous access support team, factors that may have positively affected the results. Due to the simple randomization method used in our study, the two baseline data, APTT and catheter insertion location, are inevitably distributed unevenly, so we used some statistical methods to adjust these confounding factors, such as ex ante analysis of covariance and post hoc subgroup analysis. We had 21 patients (14.2%) who withdrew from the study within the 7-day observation period (transferred from the ICU, died, or had the catheter pulled out), so the data for the four indexes of blood coagulation 7 d after the locking of the catheter contained missing values. The missing data are 9 cases (12.9%) in the heparin group and 12 cases (15.4%) in the sodium citrate group, respectively. We filled in the missing data and performed a sensitivity analysis to evaluate the robustness of the results. The sample size calculation is only performed for main outcome indicator, and the absence of sample size calculation for other outcome measures may have compromised statistical power and increased the risk of type II error, potentially resulting in false-negative findings. There are also some regrets that we did not collect whether blood products and parenteral nutrition are infused, which are risk factors for catheter occlusion. A data safety monitoring board is not used in this study since no interim analyses were undertaken.