The renal length nomogram: multivariable approach

PURPOSE: We built a multivariate renal length nomogram based on ultrasound measurements in pediatric patients with normal renal anatomy. MATERIALS AND METHODS: Included in the study were 707 children 1 week to 18 years old without vesicoureteral reflux, urinary obstruction or other known anatomical anomalies. Renal length was compared among subgroups of children. Multivariate regression approach was used to model renal length, incorporating important demographic variables. RESULTS: Subgroup comparisons of renal lengths showed diverse patterns of renal length differences in children with various demographic characteristics. In addition to age, factors significant in the multivariate nomogram model of renal length included gender, race, weight and height. CONCLUSIONS: These results show that renal length is not only age dependent, but also significantly correlates with other important demographic variables. Variability in renal length can be better described by multivariate analysis. The multivariate approach provides clinically useful information regarding renal outcomes in individuals. The ability to compare renal length among patient subgroups receiving different interventions adds additional usefulness to this approach.     

The flow rate nomogram: I. Development.

In normal individuals the flow rate depends on the initial bladder volume in a non-linear fashion. A flow rate nomogram taking this relationship into account was developed as an aid in the interpretation of urinary flow rate data. With this approach excellent differentiation of normal from obstructed individuals was achieved. In addition, the variability in a single individual's flow rate over time was estimated to be relatively small and, thus, uroflowmetry may be used to identify changes in outflow resistance after medical or surgical therapy.     

A simple nomogram for adequate haemodialysis

The publishers wouldl like to apologise for an error that occuredin the printing of the abstract by Dr van der Meulen et al.We republish below the abstract along with the correct accompanyingfigure. HD is adequate when 3 sessions per week result in a time-averagedconcentration of urea (TACu) of ± 19 mmol/1. Determinantsof TAC_u are dialyser clearance (K), dialysis time (t), volumeof distribution (V), and daily protein intake (DPI). Assumingsingle-pool kinetics, sufficient DPI, and no residual diuresis;the relations between PRE_u and POST_u are: Kt/V = ln[(Post_u/Pre_uUF/W]and DPI= [157^*(Pre_u-Post_u)]sol;(T3sol;l) + 0.176, where UF isultrafiltrate, W postdialysis weight, and T3/1 the longest interval. From these equations a nomogram for DPI (curves) and domainof adequate HD (shaded area) can be made. Combining row Postu/PreywithWL i.e. UF as %W gives Kt/V.     

A new nomogram facilitating adequate haemodilution

When using deliberate haemodilution to a certain haematocrit value (Hct), the appropriate preoperative blood volume of the patient must be determined and matched with the transfusion volume at a certain blood loss. In order to facilitate such calculations a nomogram was constructed, aiming for a final Hct of 33%. Preoperative Hct, height, weight and sex of the patient are input variables. After drawing three straight lines, the nomogram yields the normal blood volume and the acceptable pre-transfusion blood loss (BL). This nomogram was used during surgery when the preoperative Hct exceeded 35%. Protocols from 100 patients bleeding more than 50% of their BL were studied. Blood loss was 1.1 +/- 0.6 1 (mean +/- s.d.) ranging from 0.4 to 4.0 1. Fifty-one of the patients received blood transfusion. This program resulted in a decrease of Hct (mean +/- s.d.) from 41 +/- 3% preoperatively to 33 +/- 4% during the first 30 min postoperatively. Sixty-three of the patients had a final Hct of 30-35%, 13 had 27-29% and one had 26%. The low values were most likely due to underestimation and consequent unsubstituted blood loss. In summary, the nomogram makes time-consuming mathematical operations unnecessary. It was easy to use and the postoperative Hct was close to that desired in most patients.     

The evaluation of bladder outlet obstruction using the bladder weight calculation nomogram

The ultrasound estimated bladder weight (UEBW) of 15 patients (13 male, 2 female; mean age 64.7 years) who underwent pressure flow study (PFS) were evaluated using the nomogram. In the nomogram, thickness of bladder wall (T) and bladder weight (BW) were plotted on the horizontal axis and on the vertical axis, respectively. BW points calculated from various values of T by the formula were plotted on the volume-fixed bladder capacity curve. BW of each case was estimated by the nomogram from echo-measured T at maximum bladder filling and injected volume (V) into the bladder. Bladder outlet obstruction (BOO): was evaluated from obtained results, and compared with the results of PFS. The features of the distribution on Schafer's nomogram were also investigated. It was possible to estimate BW immediately after ultrasonic examination. BW was under 35 g in one patient, and over 35 g in 14 patients. Obstruction grade on the Schafer's nomogram ranged from III to VI. BOO could be evaluated quantitatively with little invasion even in patients who could not undergo PFS for urinary retention and urge incontinence. In conclusion, the bladder weight calculation nomogram immediately showed the BOO information of the patient with neither invasive technique, complicated calculation, electronic calculator nor expansive computer. This nomogram may make a breakthrough for utilizing UEBW.     

The effectiveness of warfarin dosing from a nomogram compared with house staff dosing

The purpose of this study is to address the safety and efficacy of a warfarin dosing nomogram. Patients undergoing hip or knee arthroplasty were randomized to warfarin dosed by nomogram (n = 106) or by house staff (n = 110) during their hospital stay. The average daily dose of warfarin was 4.14 mg for the nomogram group and 4.18 mg for the house staff group. On postoperative day 4, the average international normalized ratio was 1.55 in the nomogram group compared with 1.59 in the house staff group. On postoperative day 4, 19.1% of the patients in the nomogram group had a therapeutic international normalized ratio, compared with 14.7% in the house staff group. There were no differences in bleeding or thrombotic complications in the 2 groups. This nomogram appears to be both safe and effective.     

A nomogram prediction model for sternal incision problems

Presently, the incidence and mortality rates of sternal incision problems (SIPs) after thoracotomy remain high, and no effective preventive measures are available. The data on 23 182 patients at Xinqiao Hospital, Army Medical University treated with median sternotomy from 1 August 2009 to 31 July 2019 were retrospectively reviewed. A prediction model of SIPs after median thoracotomy was established using R software and then validated using the bootstrap method. Next, the validity and accuracy of the model were tested and evaluated. In total, 15 426 cases met the requirements of the present study, among which 309 cases were diagnosed with SIPs, with an incidence rate of 2%. The body mass index (BMI), intensive care unit (ICU) time, diabetes mellitus, and revision for bleeding were identified as independent risk factors for postoperative SIPs. The nomogram model achieved good discrimination (73.9%) and accuracy (70.2%) in predicting the risk of SIPs after median thoracotomy. Receiver operating characteristic curve analysis showed that the area under curve of the model was 0.705 (95% confidence interval [CI]: 0.746‐0.803); the Hosmer‐Lemeshow test showed that χ ² = 6.987 and P = 0.538, and the fitting degree of the calibration curve was good. Additionally, the clinical decision curve showed that the net benefit of the model was greater than 0, and the clinical application value was high. The nomogram based on BMI, ICU time, diabetes mellitus, and revision for bleeding can predict the individualised risk of SIPs after median sternotomy, showing good discrimination and accuracy, and has high clinical application value. It also provides significant guidance for screening high‐risk populations and developing intervention strategies.     

A nomogram predicting metastatic progression after radical prostatectomy

Objectives: To develop and internally validate a nomogram predicting the individual probability of metastatic progression after radical prostatectomy according to the length of disease‐free interval. Methods: Cox regression modeled the probability of metastatic progression of prostate cancer in 752 patients treated with radical prostatectomy with a mean follow up of 11.6 years (median 11.4; range 0.1–40.5). The significance of the predictors was confirmed in competing risks analysis, which accounts for other causes of mortality. The Cox regression model‐based nomogram was internally validated with 200 bootstrap resamples. Results: Eighty‐five of 752 patients (11.3%) developed metastatic progression. The 5, 10, 15 and 20‐year actuarial rates of metastatic progression‐free survival were, respectively, 95.9, 90.5, 84.8 and 80.5%. Pathological stage T3, elevated radical prostatectomy Gleason sum and delivery of adjuvant radiotherapy represented independent predictors of metastatic progression in both Cox and competing risks regression models, and constituted the nomogram predictors along with a fourth variable describing the presence of co‐morbidities. After 200 bootstrap resamples the nomogram achieved 80.2, 77.7, 77.6 and 76.0% accuracy in predicting metastatic progression at 5, 10, 15 and 20 years after radical prostatectomy. Conclusions: Metastatic progression is a sign of poor prognosis in men with prostate cancer. Our nomogram is able to accurately predict the conditional probability of metastatic progression up to 20 years after radical prostatectomy.     

Precystectomy nomogram for prediction of advanced bladder cancer stage

OBJECTIVE: To evaluate precystectomy prediction of pT and pN stages at cystectomy. METHODS: Multivariate logistic regression analyses modelled variables of 726 evaluable patients treated with radical cystectomy and bilateral pelvic lymphadenectomy. The first set of models predicted pT(3-4) stage at cystectomy, and the second set predicted pN(1-3) stages at cystectomy. Transurethral resection (TUR) predictors consisted of 2002 T stage, 1973 WHO tumour grade, presence of carcinoma in situ, age, gender, and delivery of neo-adjuvant chemotherapy. The area under the ROC curve quantified nomogram accuracy. Two hundred bootstrap resamples were used to reduce overfit bias. RESULTS: At TUR, 11% of patients were staged as pT(3-4) versus 42% at cystectomy. Lymph node metastases were found in 24% of patients at cystectomy (pN(1-3)). The multivariate pT(3-4) nomogram was 75.7% accurate versus 71.4% for TUR T stage. The multivariate pN(1-3) nomogram was 63.1% accurate versus 61.0% for TUR T stage. CONCLUSION: Multivariate nomograms are not perfect, but they do predict more accurately than TUR T stage alone.