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Late estimation of myocardial infarct size by total creatine kinase nomogram.

We studied the possibility of enzymatic estimation of myocardial infarct size in patients late (between days 2 and 6) after the onset of acute myocardial infarction (AMI), in whom estimation of infarct size was difficult by analysis of time-activity curves of serum creatine kinase (CK) because of the lack of the enzymatic information during the initial 48 hours. Serial determinations of serum enzymes were performed in 32 patients within 6 hours after the onset of AMI and significantly close correlations were observed between cumulative total CK release and the cardiac fraction of lactate dehydrogenase isoenzyme (LDH1) activities from day 2 to day 6 after the onset of AMI (r = 0.863 to 0.870; p less than 0.001). We developed a nomogram to estimate cumulative total CK release by serum LDH1 activities obtained between days 2 and 6 after AMI and evaluated the reliability of the nomogram. Cumulative total CK release obtained from serial serum CK activities correlated closely with total CK release obtained from the nomogram in the second group of patients with AMI (r = 0.923 to 0.946; n = 24; p less than 0.001). Our total CK nomogram requiring few blood samples was useful in late estimation of infarct size in patients who were admitted to the hospital between days 2 and 6 after the onset of AMI.

Aged↗

A simple nomogram for determination of echocardiographic left ventricular geometry.

Recent data have shown that left ventricular (LV) geometry provides additional information on the simple dichotomy of presence or absence of LV hypertrophy with regard to cardiovascular risk of hypertensive patients. A "new" class of concentric remodeling was created, identifying a rather large group of hypertensive patients who do have increased risk despite no LV hypertrophy. Because determination of LV geometry is not easy, our objective was to develop a nomogram enabling determination of LV geometry in a simple way. The geometric classification is based on the combination of increased relative wall thickness and LV hypertrophy (LV mass index > or = 125 g/m2) both of which are calculated from wall thickness and end-diastolic diameter. In the nomogram the calculated cutoff lines for relative wall thickness and left ventricular hypertrophy are plotted, forming 4 quadrants that represent the geometric classes. Two nomograms are made: 1 based on Penn convention measurement calculations and 1 based on American Society of Echocardiography convention measurements. This nomogram provides a simple way to determine LV geometry, and thus a quick assessment of the additional cardiovascular risk of the hypertensive patient. This is especially important for subjects with concentric remodeling, who would otherwise not be identified as having increased risk for cardiovascular disease.

Echocardiography↗

Pretreatment nomogram for predicting freedom from recurrence after permanent prostate brachytherapy in prostate cancer.

OBJECTIVES: To develop a prognostic nomogram to predict the freedom from recurrence for patients treated with permanent prostate brachytherapy for localized prostate cancer. METHODS: We performed a retrospective analysis of 920 patients treated with permanent prostate brachytherapy between 1992 and 2000. The clinical parameters included clinical stage, biopsy Gleason sum, pretreatment prostate-specific antigen (PSA) value, and administration of external beam radiation. Patients who received neoadjuvant androgen deprivation therapy were excluded. Failure was defined as any post-treatment administration of androgen deprivation, clinical relapse, or biochemical failure, defined as three PSA rises. Patients with fewer than three PSA rises were censored at the time of the first PSA rise. Data from two outside institutions served as validation. RESULTS: A nomogram that predicts the probability of remaining free from biochemical recurrence for 5 years after brachytherapy without adjuvant hormonal therapy was developed using Cox proportional hazards regression analysis. External validation revealed a concordance index of 0.61 to 0.64, and calibration of the nomogram suggested confidence limits of +5% to -30%. CONCLUSIONS: The pretreatment nomogram we developed may be useful to physicians and patients in estimating the probability of successful treatment 5 years after brachytherapy for clinically localized prostate cancer.

Adenocarcinoma↗

Contemporary update of prostate cancer staging nomograms (Partin Tables) for the new millennium.

OBJECTIVES: We previously presented nomograms combining preoperative serum prostate-specific antigen (PSA), clinical (TNM) stage, and biopsy Gleason score to provide the likelihood of various final pathologic stages at radical retropubic prostatectomy. The data for the original nomograms were collected from men treated between 1982 and 1996. During the past 10 years, the stage at presentation has shifted, with more men presenting with Stage T1c, Gleason score 5 to 6, and serum PSA levels less than 10.0 ng/mL. In this work, we update the "Partin Tables" with a more contemporary cohort of men treated since 1994 and with revised PSA and Gleason categories. METHODS: Multinomial log-linear regression analysis was used to estimate the likelihood of organ-confined disease, extraprostatic extension, seminal vesicle or lymph nodal status from the preoperative PSA stratified as 0 to 2.5, 2.6 to 4.0, 4.1 to 6.0, 6.1 to 10.0, and greater than 10 ng/mL, clinical (AJCC-TNM, 1992) stage (T1c, T2a, T2b, or T2c), and biopsy Gleason score stratified as 2 to 4, 5 to 6, 3 + 4 = 7, 4 + 3 = 7, or 8 to 10 among 5079 men treated with prostatectomy (without neoadjuvant therapy) between 1994 and 2000 at Johns Hopkins Hospital. The average age was 58 years. RESULTS: In this cohort, more than 60% had T1c, more than 75% had Gleason score of 6, more than 70% had PSA greater than 2.5 and less than 10.0 ng/mL, and more than 60% had organ-confined disease. Nomograms of the robust estimated likelihoods and 95% confidence intervals were developed from 1000 bootstrap analyses. The probability of organ-confined disease improved across the groups, and further stratification of the Gleason score and PSA level allowed better differentiation of individual patients. CONCLUSIONS: These updated "Partin Tables" were generated to reflect the trends in presentation and pathologic stage for men newly diagnosed with clinically localized prostate cancer at our institution. Clinicians can use these nomograms to counsel individual patients and help them make important decisions regarding their disease.

Adult↗

Frozen section diagnosis of metastatic prostate adenocarcinoma in pelvic lymphadenectomy compared with nomogram prediction of metastasis.

OBJECTIVES: To compare the sensitivity and negative predictive values of frozen section analysis of pelvic lymphadenectomy in patients undergoing radical retropubic prostatectomy for prostate adenocarcinoma with the predictive power of published nomograms for metastasis to lymph nodes. METHODS: A retrospective review was performed on all patients who underwent bilateral pelvic lymphadenectomy and radical retropubic prostatectomy for prostate adenocarcinoma between 1991 and early 1997. The sensitivity and negative predictive values were computed comparing frozen section analysis, and patients were grouped by risk stratification. Comparison was made using the McNemar text. RESULTS: The sensitivity for detecting lymph node metastasis on frozen section analysis for all risk groups was 33% (9 of 27). The sensitivity for identifying patients at high risk of having nodal metastasis by published nomograms alone was 67% (18 of 27) (P = 0.04). The overall negative predictive value for frozen section analysis was 96.5% (503 of 521). The negative predictive value for uninvolved lymph nodes, using low and intermediate-risk groups stratified by published nomograms, was 97.9% (436 of 445). CONCLUSIONS: Frozen section analysis of pelvic lymph nodes to detect metastatic prostate adenocarcinoma is less sensitive in determining which patients will have lymph nodes involved by metastatic adenocarcinoma than using risk stratification by published nomograms. The negative predictive value of frozen section analysis in all risk groups was very high, up to 97.9%.

Adenocarcinoma↗

Using the percentage of biopsy cores positive for cancer, pretreatment PSA, and highest biopsy Gleason sum to predict pathologic stage after radical prostatectomy: the Center for Prostate Disease Research nomograms.

OBJECTIVES: To develop probability nomograms to predict pathologic outcome at the time of radical prostatectomy (RP) on the basis of established prognostic factors and prostate biopsy quantitative histology. METHODS: Using information from the database of the Center for Prostate Disease Research (CPDR), univariate and multivariate analyses were performed on 1510 men who had undergone transrectal ultrasound and biopsy for diagnosis and had radical prostatectomy as primary therapy, with variables of age, race, clinical stage, pretreatment prostate-specific antigen (PSA), biopsy Gleason sum, and percentage of biopsy cores positive for cancer (total number of cores positive for cancer divided by the total number of cores obtained). The percentages of biopsy cores positive were grouped as less than 30%, 30% to 59%, and greater than or equal to 60%. The three most significant variables were used to develop probability nomograms for pathologic stage. RESULTS: PSA, biopsy Gleason sum, and percentage of cores positive were the three most significant independent predictors of pathologic stage. The assigned percentage of biopsy core-positive subgroups along with pretreatment PSA and highest Gleason sum were used to develop probability nomograms for pathologic stage. CONCLUSIONS: Pretreatment PSA, highest biopsy Gleason sum, and the percentage of cores positive for cancer are the most significant predictors for pathologic stage after radical prostatectomy. On the basis of these findings, CPDR probability nomograms were developed to predict pathologic outcome at the time of RP.

Adult↗

Activated partial thromboplastin time (aPTT) monitoring to achieve therapeutic anticoagulation before and after introducing a nomogram for adjunctive heparin treatment with thrombolytic therapy for acute myocardial infarction.

In patients with acute myocardial infarction (AMI) receiving thrombolytic therapy and i.v. unfractionated heparin, anticoagulant levels are frequently outside the target range. We evaluated the effects on anticoagulant levels before (group A) and after (group B) the introduction of a heparin nomogram in consecutive AMI-patients, receiving thrombolytic therapy and adjunctive heparin treatment. The target activated partial thromboplastin time (aPTT) was defined as 60-90 s. During the first 72 h after admission, the total number of aPTTs within the target range and the time taken to achieve the range were compared. The incidence of bleeding complications was assessed. Group A consisted of 56 and group B of 55 patients. The number of patients within the target range at 72 h (44 versus 51; chi2=4.51; P=0.034) was significantly higher in group B. No difference was found between total aPTTs within the target range (26% in group A versus 30% in group B; P=ns). Bleeding complications were slightly less in group B (7 versus in group A versus 2 patients in group B; P=ns). We concluded that the introduction of a nomogram resulted in significantly more patients with aPTTs within the target range. However, a substantial number of aPTTs before and after introduction of the nomogram were outside the target range. Moreover, this retrospective study shows that previously acquired prospective data (which showed a marked improvement of anticoagulation using a heparin nomogram) are not necessarily reproduced in the real life clinical setting.

Aged↗

Management of heparin therapy in the high-risk, chronically anticoagulated, oral surgery patient: a review and a proposed nomogram.

PURPOSE: This study analyzes the use of a standard nomogram that can help reduce the level of anticoagulation preoperatively to effectively manage perioperative heparin therapy in chronically anticoagulated oral surgery patients who are at high risk for thromboembolism. PATIENTS AND METHODS: Twenty patients with significant cardiovascular disease, ranging in age from 56 to 79 years and requiring oral surgery, were randomly divided into 2 groups. All patients were on chronic warfarin therapy, and perioperative heparinization was recommended by their cardiologist. Group A (n = 10) had their anticoagulation therapy managed with the use of a standard nomogram. The heparin therapy for group B (n = 10) was managed without the use of the nomogram. The records of all patients were analyzed for therapeutic efficacy of heparinization, number of laboratory tests required, duration of hospitalization, and complications related to heparinization. RESULTS: Patients in group A did significantly better in all parameters when compared with group B patients. There were no complications in group A, whereas there was a 20% incidence of complications related to anticoagulation therapy in group B. CONCLUSIONS: The use of a standard nomogram to manage anticoagulation therapy in the oral surgery patient requiring heparinization is strongly recommended. This provides optimal therapeutic benefit, decreases the incidence of complications, and makes the hospitalization less costly and more comfortable for the patient.

Anticoagulants↗

Nomogram of the fetal alveolar ridge: a possible screening tool for the detection of primary cleft palate.

OBJECTIVE: The objective of this study was to obtain a nomogram of the fetal alveolar ridge development, as a basis for the diagnosis of primary cleft palate. DESIGN: A cross-sectional study of 323 normal pregnant women of 14-32 weeks' gestation. Several biometric measurements were obtained throughout pregnancy, including the width of the fetal alveolar ridge. RESULTS: A nomogram of the width of the fetal alveolar ridge during 14-32 weeks' gestation is presented. A linear growth function was observed between alveolar ridge width and gestational age, biparietal diameter, head circumference, femoral length and humeral length. The alveolar ridge width in all eight cases of cleft palate was above two standard deviations and the 90th centile of our nomogram. CONCLUSION: We provide a nomogram of the growth of the fetal alveolar ridge between 14 and 32 weeks' gestation. This will aid the detection of primary cleft palate during routine prenatal sonography.

Alveolar Process↗

Nomograms as predictive models.

Nomograms are valuable tools for estimating the likelihood of cancer being diagnosed, the pathologic features of a localized cancer, and the prognosis of a patient after treatment. Although the available nomograms are reasonably accurate, better predictive factors including additional clinical factors and new molecular analyses are needed to improve the accuracy or predictions. Nomogram performance will also be enhanced with larger datasets of patients and longer follow-up. We review the concepts of risk stratification and the development and use of nomograms as predictive tools.

Expert Systems↗

Evaluation of six gentamicin nomograms using a bayesian parameter estimation program.

A new set of guidelines for the administration of gentamicin was developed by estimating steady-state peak and trough gentamicin concentrations for simulated patients with known weights and creatinine clearances. The most appropriate doses to achieve target peak concentrations of 5-10 mg/L and troughs of less than 2 mg/L were then tabulated. The performance of these new guidelines was assessed using data collected from 60 patients who had received gentamicin and had at least two serum concentration measurements. Individual estimates of clearance and volume of distribution were obtained using a Bayesian parameter estimation program and these estimates were used to predict the steady-state peak and trough concentrations that would arise from the new guidelines and five other previously published nomograms (Mawer, Chan, Hull-Sarubbi, Rule of Eight, and Dettli). The new guidelines, the Dettli nomogram, and the Hull-Sarubbi table achieved similar percentages (52-57%) of patients within the target ranges (5-10 mg/L for peak and less than 2 mg/L for trough), although 28% of patients had predicted peak concentrations below 5 mg/L with the new method compared to 15% with the other two. Only 38% of patients were within both ranges when the Mawer nomogram and the Rule of Eight methods were used. Since a large percentage of patients would have achieved concentrations outside of the target ranges no matter which nomogram was used, serum concentration monitoring is still recommended to confirm dose requirements.

Bayes Theorem↗

Counseling men with prostate cancer: a nomogram for predicting the presence of small, moderately differentiated, confined tumors.

PURPOSE: Men diagnosed with clinically localized prostate cancer have a number of treatment options available, including watchful waiting, radical prostatectomy and radiation therapy. With the widespread use of serum prostate specific antigen (PSA) testing, prostate cancers are being diagnosed earlier in their natural history, with many tumors being small and of little health risk to the patient, at least in the short term. To better counsel men diagnosed with prostate cancer, we developed a statistical model that accurately predicts the presence of small moderately differentiated, confined cancer based on clinical variables (serum PSA, clinical stage, prostate biopsy Gleason grade and ultrasound volume) and variables derived from the analysis of systematic biopsies. MATERIALS AND METHODS: The analysis included 409 patients diagnosed by systematic needle biopsy with clinical stages T1c or T2a N0 or NX and M0 or MX prostate cancer who were treated solely with radical prostatectomy at 1 of 2 institutions. Additional biopsy features included number and percentage of biopsy cores involved with cancer and high grade cancer, in addition to total length of biopsy cores involved. Indolent cancer was defined as pathologically organ confined cancer 0.5 cc or less in volume and without poorly differentiated elements. Logistic regression was used to construct several prediction models and the resulting nomograms. RESULTS: Overall 80 (20%) of the patients had indolent cancer. The nomogram predicted the presence of an indolent cancer with discrimination (area under the receiver operating characteristics curves) for various models ranging from 0.64 to 0.79. Calibration of the models appeared good. CONCLUSIONS: Nomograms incorporating pretreatment variables (clinical stage, Gleason grade, PSA and the amount of cancer in a systematic biopsy specimen) can predict the probability that a man with prostate cancer has an indolent tumor. These nomograms have good discriminatory ability and calibration, and may benefit the patient and clinician when the various treatment options for prostate cancer are being considered.

Biomarkers, Tumor↗

Prognostic nomogram for patients undergoing resection for adenocarcinoma of the pancreas.

BACKGROUND: Predictive nomograms are becoming increasingly used to define and predict outcome. They can be developed at presentation or following treatment and include variables not conventionally used in standard staging systems. METHODS: We use a predictive nomogram based on prospectively collected data from 555 pancreatic resections for adenocarcinoma at a single institution. At last follow-up, 481 (87%) had died, defining a mature and comprehensive database. We used a 1-, 2-, and 3-year follow-up, as the number of patients alive beyond 3 years is sufficiently limited to provide insufficient events. RESULTS: Based on a Cox model, we then developed a nomogram that predicts the probability that a patient will survive pancreatic cancer for 1, 2, and 3 years from the time of the initial resection, assuming that there is not death from an alternate cause. Calibration between observed and corrected is good, and variables not conventionally associated with standard staging systems improved the predictivity of the model. CONCLUSIONS: This nomogram can serve as a basis for investigating other potentially predictive variables that are proposed of prognostic importance for patients undergoing resection for adenocarcinoma of the pancreas.

Adenocarcinoma↗

Comparison of gentamicin dose estimates derived from manual calculations, the Australian 'Therapeutic Guidelines: Antibiotic' nomogram and the SeBA-GEN and DoseCalc software programs.

AIM: To compare gentamicin dose estimates from four predictive methods. METHODS: A retrospective study was conducted, comprising patients at Fremantle Hospital who received gentamicin therapy and had at least one gentamicin serum concentration reported. A manual calculation method, the Australian 'Therapeutic Guidelines: Antibiotic' (TGA) nomogram and the SeBA-GEN and DoseCalc software packages were compared. SeBA-GEN dose estimates were regarded as the reference standard. RESULTS: There were 64 males and 30 females with mean age of 58 +/- 16 years. In patients with moderate renal impairment (CL(Cr) = 30-60 ml min(-1); n = 21), mean dose estimates using DoseCalc and the manual calculation method were comparable to SeBA-GEN but the mean TGA nomogram dose (230 mg; 95% confidence interval 179, 281) was significantly lower than SeBA-GEN (286 mg; 261, 311; P = 0.002; one-way RM anova). In patients with mild renal impairment (CL(Cr) = 60-90 ml min(-1); n = 48), DoseCalc (392 mg; 367, 427) was comparable to SeBA-GEN (377 mg; 362, 392). Although the manual method (341 mg; 306, 376; P = 0.007) and the TGA nomogram (335 mg; 302, 368; P < 0.001) estimates were significantly lower than SeBA-GEN, the practical difference was modest. CONCLUSIONS: SeBA-GEN and DoseCalc are generally comparable for estimation of gentamicin doses in patients with renal impairment. The 'Therapeutic Guidelines: Antibiotic' nomogram is a valid approach to dosage estimation, but only when used in patients with normal renal function. Simple manual calculations are a suitable alternative in patients with renal impairment.

Anti-Bacterial Agents↗

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.

Adult↗

A theoretical derivation of the nomograms for permanent prostate brachytherapy.

This study calculates the required minimum radioactivity to deliver a prescribed dose of radiation to a target using radioisotopes in permanent prostate brachytherapy. Assuming the radioactivity to be in a continuous form, an integral equation--Fredholm equation of the first kind, can be formulated with the radioactivity density used as the variable. The density distribution to produce a uniform volume dose rate is determined using a quadrature method and the radial profile behaves smoothly from the zero radius, and peaks sharply approaching the volume boundary. The density for Pd-103 is about 1.5 times that of I-125 due to its higher spatial attenuation. A nomogram is the relationship between the total activity per unit dose (A) and the dimension of the volume (d). Expressing the nomogram as A=c X dn U/Gy, then (c,n)= [(0.0098, 2.09) I-125] and [(0.031, 2.25) Pd-103]. Compared with the Memorial nomogram, (c,n)=[(0.011,2.2) I-125] and [(0.036,2.56) Pd-103], or that quoted by AAPM TG64, (c,n)=[(0.014,2.05) I-125] and [(0.056,2.22) Pd-103], our calculation determined an average 33% and 35% decrease for I-125, and 89% and 77% decrease for Pd-103, respectively. Two reasons for the extra total activity found in the Memorial and AAPM nomograms are: (a) An imperfect clinical situation limited by the restraints of implant techniques (e.g., use of templates) associated with the presence of adjacent normal organs, and (b) source discretization into seeds. When radioactivity is clumped as discrete seeds, higher activity is needed because of "wastage" in two aspects: (a) Dose cold-spots at intersource spaces, (b) hot-spots around the sources. Thus in theory, use of lower activity seeds will require less total activity to deliver a prescribed dose. Based on our study, Pd-103 delivers a higher therapeutic ratio and a lower integral dose to the patient compared to I-125.

Brachytherapy↗

Nomograms for calculation of oxygen consumption and respiratory exchange ratio.

Nomograms have been prepared whereby the respiratory exchange ratio may be derived from the concentrations of carbon dioxide and oxygen in expired gas and oxygen consumption from the volume and oxygen concentration of expired gas; they apply only to patients breathing room air. The nomogram for the respiratory exchange ratio has an error of less than 0.01, which is the limit of visual discrimination on the nomogram. The nomogram for oxygen consumption has an error of standard deviation 7.73 ml/min. This error may be substantially reduced by excluding cases with a respiratory exchange ratio outside the range 0.70-0.93. Under these conditions the maximum error was 10 ml/min, which is acceptable for a wide range of clinical purposes.

Air↗

Acid-base curve nomogram for chimpanzee blood and comparison with human blood characteristics.

An acid-base nomogram for chimpanzee blood was constructed. Blood was drawn from eight lightly anesthetized chimpanzees. Each sample of blood was oxygenated and nine aliquots were prepared with three different concentrations of hemoglobin and three different amounts of added acid or base. Each aliquot was equilibrated at two PCO2 levels and the pH was measured and plotted on pH-logPCO2 coordinates. Using the intersection point of these pH-logPCO2 lines as a point of equal hemoglobin-independent "base excess" for each condition, values for true base excess were plotted. Connecting these values provided a Cartesian PCO2-pH base excess nomogram for the chimpanzee comparable to that devised by Siggaard-Andersen for humans. Examination of blood from normal human subjects by the same methods showed no appreciable differences from the original Siggaard-Andersen nomogram. However, the PCO2-pH-base excess nomogram for chimpanzee blood deviated slightly from that for human blood. It is possible that the deviation is related to an arterial bicarbonate concentration in the chimpanzee slightly higher than that in human.

Acid-Base Equilibrium↗