Objective: 1. Construct a risk prediction model to predict the factors of high intraoperative bleeding in patients undergoing posterior lumbar decompression and fusion internal fixation surgery during outpatient visits. 2. Implement pre-hospital blood management for surgery patients, to improve clinical outcomes.
Design & methods: We collected patients who underwent two-segment and three-segment posterior lumbar decompression and fusion internal fixation surgery in our hospital from 2016 to 2021. A total of 24 preoperative indicators were analyzed, covering medical history, demographic characteristics, segment, operator and laboratory test results. We used a logistic regression model to optimize the model's feature selection. The predictive model was constructed using the multivariable logistic regression method with all included methods, and a nomogram was created to display the model. Activated partial thromboplastin time, surgeon volume, American Society of Anesthesiologists classification, body mass index, and the number of fusion and fixation lumbar segments were used to construct the predictive model. The predictive model's discrimination, calibration, clinical applicability, and rationality were evaluated.
Results: The predictive model's area under the receiver operating characteristic curve is 0.723, with a 95% confidence interval of (0.685-0.760). The training set's decision curve analysis demonstrates that applying this diagnostic curve will increase the net benefit when the threshold probability is between 5% and 40%.
Conclusion: This study developed a novel nomogram with relatively good accuracy to assist clinical doctors in assessing the high intraoperative bleeding risk in patients undergoing posterior lumbar decompression and fusion internal fixation surgery during outpatient visits. By evaluating individual risk, surgeons can develop an individualized treatment plan to reduce the risk of intraoperative bleeding for each patient.
Introduction: Serum cystatin C (CysC) is used to estimate glomerular filtration rate (eGFR), including in the Chronic Kidney Disease in Children (CKiD) Under 25 years (U25eGFR) equations. Several CysC measurement procedures available from diagnostic vendors include reference material for calibration, but the extent of heterogeneity across manufacturers is unclear. Since heterogeneity may have clinical and research implications for eGFR, we evaluated three CysC procedures in samples from the CKiD study representing a wide spectrum of kidney function.
Materials and methods: The three CysC measurement procedures evaluated were: Siemens BN II N Latex CystatinC Assay; Gentian CystatinC Immunoassay; and Roche Tina-quant CystatinC Gen.2. Bland-Altman quantified agreement with Siemens as reference because that method was used for longitudinal CKiD samples from 2003 to 2023. We present derivation of the interquartile range (IQR) of U25eGFR as a measure of precision and describe differences outside this range.
Results: From 53 samples from 44 participants, Gentian measurements were 7 % higher than Siemens (95 %CI: +5.6 %,+8.5 %), while Roche measurements were 4.8 % lower on average (95 %CI: -6.2 %,-3.3 %). Both had very high correlation: 0.9926 and 0.9906, respectively. There was strong agreement across procedures, but a simple correction factor of 7 % reduction applied to Gentian yielded unbiased estimates (+0.03 %, 95 %CI: -1.3 %,+1.4 %) and strong performance in Deming regression. For precision, 98 % of U25eGFR values based on Gentian and Roche CysC were each within the IQR of the Siemens-based estimates.
Conclusions: Despite reference material calibration, heterogeneity across CysC measurement procedures was observed. Procedure variability was within the limits of U25eGFR estimates indicating that practically, all procedures are appropriate for clinical use. Clinicians may consider calculating IQR of U25eGFR estimates for pediatric chronic kidney disease management.