安田 英人

AIM: This study investigated the risk factors of peripheral intravenous catheter (PIVC)-related phlebitis in critically ill patients according to the duration of catheter dwelling. METHODS: This was a post-hoc analysis of the AMOR-VENUS study involving 23 intensive care units (ICUs) in Japan. We included patients aged ≥ 18 admitted to the ICU and had PIVCs inserted during ICU admission. The primary outcome measure was phlebitis, and the risk factors of phlebitis were evaluated based on hazard ratios (HR) and 95% confidence intervals (CI). The duration of catheter dwelling was classified as (i) ≤ 24 h; (ii) > 24 h, ≤ 72 h; and (iii) > 72 h. Multivariable marginal Cox regression analysis was performed using the presumed risk factors for each group. RESULTS: In total, 1,335 patients and 3,348 PIVCs were evaluated. Among patients with ≤ 24 h of catheter dwelling, phlebitis occurrence was associated with ICU admission for non-surgical management with ICU admission for elective surgery as the reference, standardized drug administration in the ICU, and dexmedetomidine administration in the ICU. Among those with > 24 h but ≤ 72 h of catheter dwelling, it was associated with male sex with female sex as the reference, tetrafluoroethylene as the catheter material with polyurethane as the reference, nicardipine administration, and noradrenaline administration. Among those with > 72 h of catheter dwelling, it was associated with a catheter size ≥ 18 G and nicardipine administration. CONCLUSION: The risk factors for phlebitis varied with the duration of catheter dwelling. Individualized catheter management, considering the duration of catheter dwelling, may help avoid phlebitis in patients admitted to the ICU.

AIM: To develop and evaluate a predictive model for delayed pseudoaneurysm formation after non-operative management (NOM) in children with blunt splenic injuries. METHODS: A post hoc analysis of a multicenter cohort study in Japan included patients aged ≤16 years who underwent NOM for isolated blunt splenic injuries. The outcome was the formation of a pseudoaneurysm, which was not identified on admission and confirmed at least 24 h after admission. Predictors were determined from data available within 24 h of hospital arrival. Five predictive models were developed using logistic regression analysis and evaluated using discrimination (receiver operating characteristic [ROC] and precision-recall curve [PRC]), calibration (calibration plot and Brier score) and decision curve analysis (DCA) with bootstrap resampling data. RESULTS: Pseudoaneurysms developed in 41 (9.4%) of 434 cases of isolated splenic injury in our cohort. Model 1 (19 predictors) had the highest ROC (0.828) and PRC (0.358), followed by model 5 (8 predictors; ROC 0.805, PRC 0.295). Calibration was similar across models, indicating good calibration. Models 1 and 5 outperformed the other DCAs. Overall, model 5, incorporating factors such as age, sex, Injury Severity Score, American Association for the Surgery of Trauma-Organ Injury Scale, contrast extravasation on computed tomography, concomitant injuries, cryoprecipitate dose and NOM details, was simpler and showed better predictive ability than the other models. CONCLUSION: A predictive model for delayed pseudoaneurysm formation was developed with moderate discrimination and calibration. Further improvement using different modelling methods, such as machine learning, may be necessary.

Purpose: Peripheral intravenous catheter (PIVC)-administered noradrenaline offers faster treatment for septic shock but risks complications like phlebitis. We aimed to investigate the relationship between the total noradrenaline dose administered via PIVCs and the development of phlebitis by considering the influence of noradrenaline as a time-dependent covariate. Methods: A post hoc analysis was conducted on prospective multicenter cohort data from 23 intensive care units in Japan. The total noradrenaline dose was included as a time-dependent variable in a multilevel Cox regression model, and smoothing splines assessed nonlinear relationships. The primary endpoint was phlebitis. Directed acyclic graphs were used to define confounding factors for the analysis. Results: The analysis included 3410 PIVCs from 1351 patients, with noradrenaline administered to 70 patients (5.2%) with 91 PIVCs (2.6%). The median dwell time and interquartile range of PIVCs was 46.2 h (21.3-82.9). No significant association was observed between the total noradrenaline dose and the occurrence of phlebitis through analysis using the multilevel Cox regression model with time-dependent covariate, which assumed the linear relationship between phlebitis occurrence and the total noradrenaline dose (hazard ratio 1.06, 95% confidence interval [CI] 0.93-1.20). Spline curve analysis suggested a nonlinear relationship between the total noradrenaline dose and phlebitis, and the risk of phlebitis increased when the total administered dose of noradrenaline exceeded 6 mg as the lower limit of the 95% CI exceeded the significant threshold of 1.0. Sensitivity analyses, including additional potential risk factors, showed consistent results compared with those of the primary analysis. Conclusions: Administering noradrenaline within a total dose not exceeding 6 mg reduces the risk of phlebitis, potentially allowing safer administration through PIVCs. Trial Registration: UMIN Clinical Trials Registry (UMIN-CTR): UMIN000028019.