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PubMed1983

Acid-base curve and alignment nomograms for swine blood.

To construct acid-base curves and alignment nomograms for swine blood, we added known amounts of acid or base to aliquots of swine blood with three different concentrations of hemoglobin. Pairs of blood samples were equilibrated at two different CO2 partial pressures, and blood pH was measured. Data were analyzed by computer, and mean values were created for complete data of four swine. Curve and alignment nomograms were constructed by computer. The resultant nomograms for swine blood differ from those constructed by Siggaard-Andersen for human blood, most importantly at base-excess values of +10 to +25 mmol/l. The possible reasons for the observed differences are discussed and, although not completely resolved, may be related in large measure to the accuracy of pH determination and the methodology of nomogram construction.

Acid-Base Equilibrium↗

PubMedDate not supplied

Prospective assessment of a nomogram for the initiation of oral anticoagulation therapy for outpatient treatment of venous thromboembolism.

Venous thromboembolism is a common medical problem. Recently, the emphasis has been on a switch to outpatient low molecular weight heparin therapy. Previous warfarin nomograms have been developed only for inpatients. We prospectively assessed a warfarin initiation nomogram in 105 consecutive outpatients; the nomogram requires International Normalized Ratio (INR) testing on only days 3, 5, and 8. Eighty-three percent had a therapeutic INR by day 5 and 98% by day 8. There were no major bleeds and only 6 instances of INR >4.5. This outpatient warfarin nomogram appears to be safe and efficacious in obtaining timely therapeutic levels of warfarin and deserves further study.

Adult↗

PubMed2000

Nomograms used to define the short-term treatment with PGE(1) in patients with intermittent claudication and critical ischemia. The ORACL.E (Occlusion Revascularization in the Atherosclerotic Critical Limb) Study Group. The European Study.

Infusional, cyclic PGE1 treatment is effective in patients with intermittent claudication and critical limb ischemia (CLI). One of the problems related to chronic PGE1 treatment in vascular diseases due to atherosclerosis is to evaluate the variations of clinical conditions due to treatment in order to establish the number of cycles per year or per period (in severe vascular disease reevaluation of patients should be more frequent) needed to achieve clinical improvement. In a preliminary pilot study a group of 150 patients (mean age 67+/-12 years) with intermittent claudication (walking range from 0 to 500 m) and a group of 100 patients with CLI (45% with rest pain, and 55% gangrene; mean age 68 +/-11 years) the number of PGE1 cycles according to the short-term protocol (STP) needed to produce significant clinical improvement was preliminarily evaluated. Considering these preliminary observations, the investigators established a research plan useful to produce nomograms indicating the number of cycles of PGE1-STP per year needed to improve the clinical condition (both in intermittent claudication and CLI). A significant clinical improvement was arbitrarily defined as the increase of at least 35% in walking distance (on treadmill) and/or the disappearance of signs and symptoms of critical ischemia in 6 months of treatment in at least 75% of the treated patients. With consideration of the results obtained with the preliminary nomograms a larger validation of the nomograms is now advisable. A cost-effectiveness analysis is also useful to define the efficacy of treatment on the basis of its costs. The publication of this report in two angiological journals (Angeiologie and Angiology) will open the research on nomograms to all centers willing to collaborate to the study. The data are being collected in the ORACL.E database and will be analyzed within 12 months after the publication of this report.

Aged↗

PubMed1999

Postoperative nomogram for disease recurrence after radical prostatectomy for prostate cancer.

PURPOSE: Although models exist that place patients into discrete groups at various risks for disease recurrence after surgery for prostate cancer, we know of no published work that combines pathologic factors to predict an individual's probability of disease recurrence. Because clinical stage and biopsy Gleason grade only approximate pathologic stage and Gleason grade in the prostatectomy specimen, prediction of prognosis should be more accurate when postoperative information is added to preoperative variables. Therefore, we developed a postoperative nomogram that allows more accurate prediction of probability for disease recurrence for patients who have received radical prostatectomy as treatment for prostate cancer, compared with the preoperative nomogram we previously published. PATIENTS AND METHODS: By Cox proportional hazards regression analysis, we modeled the clinical and pathologic data and disease follow-up for 996 men with clinical stage T1a-T3c NXM0 prostate cancer who were treated with radical prostatectomy by a single surgeon at our institution. Prognostic variables included pretreatment serum prostate-specific antigen level, specimen Gleason sum, prostatic capsular invasion, surgical margin status, seminal vesicle invasion, and lymph node status. Treatment failure was recorded when there was either clinical evidence of disease recurrence, a rising serum prostate-specific antigen level (two measurements of 0.4 ng/mL or greater and rising), or initiation of adjuvant therapy. Validation was performed on this set of men and a separate sample of 322 men from five other surgeons' practices from our institution. RESULTS: Cancer recurrence was noted in 189 of the 996 men, and the recurrence-free group had a median follow-up period of 37 months (range, 1 to 168 months). The 7-year recurrence-free probability for the cohort was 73% (95% confidence interval, 68% to 76%). The predictions from the nomogram appeared to be accurate and discriminating, with a validation sample area under the receiver operating characteristic curve (ie, a comparison of the predicted probability with the actual outcome) of 0.89. CONCLUSION: A postoperative nomogram has been developed that can be used to predict the 7-year probability of disease recurrence among men treated with radical prostatectomy.

Adult↗

PubMed1995

A nomogram for predicting optimal dosage of cyclosporine in renal transplant patients: taking physiological factors into consideration for regimen during immunosuppressive therapy.

We constructed a nomogram for determining the optimal regimen of cyclosporine (CyA), based on physiological changes that occur during immunosuppressive therapy. The nomogram consists of a fixed model and a variable model. In the fixed model, the oral dose of CyA (D, mg/kg) is given by the multiple linear function of logarithmic CyA trough level (TL, ng/ml), the surrogate apparent total body clearance of CyA (CL/fsu, l/h/kg, being equal to D/TL/12), and the erythrocyte-to-plasma distribution ratio of CyA (CyA-EP), as defined by: D = 4.938 x log(TL) + 1.5037 x CL/fsu - 0.0326 x CyA-EP - 10.7156. In the variable model, the CL/fsu is given by the CyA-EP and the patient's intrinsic parameters (P1, P2), using a nonlinear equation: CL/fsu = P1 x exp(P2 x CyA-EP)/CyA-EP. An optimal CyA dose to maintain a desired trough level was calculated, and the validity of the nomogram was found satisfactory for clinical use. This offers a very concise and practical method for the therapeutic monitoring of CyA. Because the pharmacokinetics of CyA depends on physiological changes due to several disease states, and because the CyA-EP reflects the pharmacokinetics of CyA and the patient's disease state, the proposed nomogram is believed to provide an optimal dosage adjustment, taking physiological factors into consideration.

Adolescent↗

PubMedDate not supplied

Spirometric nomograms for normal children and adolescents in Puerto Rico.

OBJECTIVE: The use of spirometric reference values specific to the population being tested is preferable. A study carried out in Puerto Rico is used here to develop nomograms for normal children and adolescents based on age and height, two variables that have been found to be good predictors of pulmonary function. MATERIAL AND METHODS: The data for healthy individuals aged 5 to 18 were extracted (108 girls and 107 boys) from a larger study of spirometric measurements collected on 4527 individuals attending medical services in Puerto Rico. Several models were tested for the prediction of FEV1, FVC and the ratio FEV1/FVC. The best models were selected for each gender, and nomograms were developed showing the fifth, twenty-fifth, fiftieth, seventy-fifth, and ninety-fifth percentile of the predicted values according to age and height separately. RESULTS: The best models were those using the logarithm of the pulmonary function and the cube of height (R2 = 0.79-0.81), and age without transformation (R2 = 0.73-0.77). Corresponding nomograms were developed based on these models. The ratio showed little variation for different ages and heights. CONCLUSIONS: Pulmonary function can be efficiently predicted by age and height. Nomograms provide a simple way to use spirometric references that can be incorporated to clinical practice.

Adolescent↗

PubMed1986

Double-lined nomogram of cervical dilatation in Chinese primigravidas.

By studying normal labors in 500 Chinese primigravidae, a nomogram has been constructed to show the normal progression of cervical dilatation starting from cervical os of 3 cm dilatation. Paralleled 'alert' lines and 'action' lines were derived from this nomogram. Clinical evaluation of this double-lined nomogram showed that poor progression of cervical dilatation resulting in an abnormal outcome can be predicted at earlier stages. The use of this nomogram together with the partogram greatly improved the management of labor in the individual patient and the guidance of the labor ward as a whole.

Adolescent↗

PubMedDate not supplied

Laser in situ keratomileusis nomogram development.

BACKGROUND: There is no standard laser in situ keratomileusis (LASIK) nomogram for the Nidek EC-5000 excimer laser when used with current software versions 2.23 or 2.25. Nomogram tables developed by various EC-5000 users differ significantly from one another. METHODS: We analyzed the results of our first 138 eyes treated for myopia and myopic astigmatism with the Nidek EC-5000 excimer laser, model 2b, long working distance. In addition to analyzing standard clinical outcomes, the correction values entered into the laser were compared to the achieved change in refraction for these eyes. A global nomogram parameter was created, incorporating the effect of optical zone size and patient age. After observing initial overcorrections, we elected to treat most of the eyes using a 20% reduction of the attempted spherical correction. RESULTS: The mean value for the attempted change in spherical equivalent refraction was -6.85 D. This correction was achieved with a standard deviation of -0.04 D at 1 month, -0.08 D at 3 months, and -0.09 D at 6 months after LASIK. The postoperative values for the uncorrected and spectacle-corrected visual acuity were similar to other published studies. However, scatterplots comparing the laser settings to achieved postoperative refractions showed a clear 20% trend toward overcorrection. This trend increased with patient age and optical zone diameter. CONCLUSIONS: The basic calibration values (factory standard) for software versions 2.23 and 2.25 are too aggressive for LASIK treatments. When using optical zone diameters of 6 mm and above, the spherical refraction values entered into the laser must be reduced by at least 20%. LASIK nomograms for the Nidek EC-5000 excimer laser should be specific for optical zone diameter and patient age.

Adolescent↗

PubMed2003

Comparison of 10-mg and 5-mg warfarin initiation nomograms together with low-molecular-weight heparin for outpatient treatment of acute venous thromboembolism. A randomized, double-blind, controlled trial.

BACKGROUND: The optimal means of achieving therapeutic oral anticoagulation in the outpatient setting has not been determined. OBJECTIVE: To compare a 10-mg dosing nomogram with a 5-mg nomogram that has been suggested to be sufficient for warfarin initiation. DESIGN: Randomized, controlled clinical trial. SETTING: Outpatient venous thromboembolism services of four tertiary care hospitals. PATIENTS: 201 of 210 consecutive patients with objectively confirmed diagnoses of acute venous thromboembolism. INTERVENTION: All patients were treated with subcutaneous low-molecular-weight heparin for a minimum of 5 days until a therapeutic international normalized ratio (INR) was achieved. Patients were randomly assigned to initially receive a 10-mg or 5-mg dose of warfarin. MEASUREMENTS: The primary end point was time in days to therapeutic INR. Secondary end points were the proportion of patients who had achieved a therapeutic INR by day 5, the total number of INR assessments, the number of INR measurements greater than 5.0, incidence of recurrent venous thromboembolism and major bleeding, and survival. RESULTS: 210 consecutive patients met the inclusion criteria. Of these, 9 were excluded and 201 were randomly assigned to study groups (104 to the 10-mg group and 97 to the 5-mg group). Demographic characteristics of both groups were similar. Patients in the 10-mg group achieved therapeutic INR 1.4 days earlier than patients in the 5-mg group (P < 0.001). Eighty-three percent of patients in the 10-mg group achieved a therapeutic INR by day 5 versus 46% in the 5-mg group (P < 0.001). Fewer INR assessments were performed in the 10-mg group than in the 5-mg group (8.1 vs. 9.1; P = 0.04). There were no significant differences between the two groups in recurrent events, major bleeding, survival, and number of INR measurements greater than 5.0. CONCLUSION: The 10-mg warfarin initiation nomogram is superior to the 5-mg nomogram because it allows more rapid achievement of a therapeutic INR.

Acute Disease↗

PubMed1994

Evaluation of pulsatility index nomograms based on fetal biometry in small for gestational age fetuses.

Reference limits for the PI from the umbilical, middle cerebral, and renal arteries were constructed using BPD, AC, FL, and transverse cerebellar diameter as independent variables and their efficacy tested in a population of SGA fetuses. Therefore, 153 normal fetuses and 90 SGA fetuses with established dates between 20 and 40 weeks of gestation were considered. Normal fetuses showed a linear negative relationship between the PI from all the vessels investigated and all the biometric parameters considered. Although the BPD related better with the PI from the umbilical artery (r = 0.646) and the renal artery (r = 0.765) and the transverse cerebellar diameter related better with middle cerebral artery PI values (r = 0.510), no evident differences in fitting were found among the variables tested. In SGA fetuses the nomograms on BPD, AC, and FL significantly underestimated PI values in all the vessels studied when compared to the nomograms based on gestational age, while a similar ability in identifying abnormal PI values was found for nomograms based on gestational age and transverse cerebellar diameter. These newly developed nomograms based on transverse cerebellar diameter may prove useful in the evaluation of Doppler indices of fetuses with uncertain gestational age.

Embryonic and Fetal Development↗

PubMed2001

A postoperative prognostic nomogram for renal cell carcinoma.

PURPOSE: Few published studies have combined prognostic factors to predict the likelihood of recurrence after surgery for renal cell carcinoma. We developed a nomogram for this purpose. MATERIALS AND METHODS: With Cox proportional hazards regression analysis, we modeled pathological data and disease followup for 601 patients with renal cell carcinoma who were treated with nephrectomy. Predictor variables were patient symptoms, including incidental, local or systemic, histology, including chromophobe, papillary or conventional, tumor size, and pathological stage. Treatment failure was recorded when there was either clinical evidence of disease recurrence or death from disease. Validation was performed with a statistical (bootstrapping) technique. RESULTS: Disease recurrence was noted in 66 of the 601 patients, and those in whom treatment was successful had a median and maximum followup of 40 and 123 months, respectively. The 5-year probability of freedom from failure for the patient cohort was 86% (95% confidence interval 82 to 89). With statistical validation, predictions by the nomogram appeared accurate and discriminating with an area under the receiver operating characteristic curve, that is a comparison of the predicted probability with the actual outcome of 0.74. CONCLUSIONS: A nomogram has been developed that can be used to predict the 5-year probability of treatment failure among patients with newly diagnosed renal cell carcinoma. The nomogram may be useful for patient counseling, clinical trial design and patient followup planning.

Carcinoma, Renal Cell↗

PubMed2002

A nomogram for single-stage cluster-sample surveys in a community for estimation of a prevalence rate.

BACKGROUND: Proper assessment of the magnitude of the problem is essential for devising adequate allocation of available resources and for developing future strategies to combat a disease. The cluster random sampling (CRS) technique is commonly used for rapid assessment of public health problems in developing countries. Our objective is to devise a nomogram that can instantly provide the number of clusters of specified size needed to estimate the prevalence rate of a disease in a community with given precision, ratio of design-effect to cluster size and confidence level. This would be applicable only to single-stage CRS. METHODS: We use a logarithmic transformation to linearize the relation between the number of clusters (C) on one side and design-effect (D), cluster size (B), precision (L), anticipated prevalence rate (P) and confidence level (alpha) on the other. By using this relation, we construct a nomogram using established methods. RESULTS: A nomogram is obtained that can be used to determine the number of clusters needed in a survey with the help of only a ruler when other parameters are known. This is a 6-in-1 figure as it gives the number of clusters C corresponding to any combination of alpha from among the popularly used 0.05, 0.10 and 0.20, and precision 10% of P or 20% of P. Using a very simple calculation, the number of clusters for the other values of alpha and L can also be obtained. CONCLUSION: This nomogram can be a useful aid in instantly providing the number of clusters required to rapidly estimate the prevalence rate of a disease in a community when the ratio of design-effect to cluster size, confidence level, and precision are specified. However, it is not applicable to intervention studies where interest mainly focuses on testing a hypothesis rather than estimation.

Cluster Analysis↗

PubMed2003

Fetomaternal Doppler sonography nomograms.

PURPOSE: To constitute Doppler flow velocity nomograms for use in obstetric clinics and to analyse the technical infrastructure of constructing Doppler sonography nomograms for clinical use. METHODS: On a cross-sectional study plan basis 602 flow results of 370 pregnant women were used. Pregnancy gestational ages were confirmed with an early sonogram prior to the 14th gestational week. Patients in whom primary section for placental insufficiency had to be done, who had pathological fetal heart rate monitoring, signs of intrauterine asphyxia, multiple pregnancy or a fetal anomaly were excluded. Every two gestational weeks patients were grouped and for these groups the 5th, 10th, 50th, 90th and 95th percentiles were calculated to represent the umbilical artery, fetal aorta, middle cerebral artery (MCA) and uterine artery S/D ratio, resistence index (RI) and pulsatility index (PI) Doppler flow velocity nomograms. RESULTS: In normal pregnancies, after the 22nd-24th gestational week, the uteroplacental flow velocities were constant, but at the fetal vessels there were changes in velocity waveforms after this period. With advancing gestation in the third trimester, umbilical artery and middle cerebral artery impedance was lower and the resistance in the descending fetal aorta remained nearly constant. CONCLUSION: With growing gestational age the Doppler velocity forms change. In fact because of this, for Doppler velocity studies and to differentiate between normal and abnormal pregnancy status, nomograms adapted to gestational age should be used. For practical use in different obstetrics clinics, we are presenting our Doppler velocity norm-curves.

Adult↗

PubMed1975

[PO-2-PCO-2-pH-nomograms for rat blood at 37 degrees C (author's transl)].

In order to determine the interdependence of the parameters of the respiratory gas transport in rat blood (Sprague-Dawley) CO-2-equilibration curves in fully oxygenated and deoxygenated blood are measured. The results are presented in the form of pH-log P-CO-2-diagrams. O-2-dissociation curves of rat blood are registered at different CO-2 partial pressures. The P-02 at S-02 equals 50% ranged between 27.7 mm Hg for P-C0-2 equals 20 mm Hg. 35.1 mm Hg for P-C0-2 equals 40 mm Hg and 42.2 for P-C0-2 equals 60 mm Hg. Cartesian and alignment nomograms are constructed using CO-2 equilibration curves and O-2 dissociation curves. These nomograms give the interrelations between P-O-2, P-CO-2, pH and S-0-2 of rat blood. Separate nomograms are presented for Hb-concentrations of 10-13 g-% and 13.1-16 g-% because of great variations of Hb concentration in rat blood. If two of these values are known the nomograms permit the reading of the remaining paramters.

Animals↗

PubMed1986

The clinical utility of a published nomogram to predict aminoglycoside nephrotoxicity.

Moore and colleagues recently published a nomogram for predicting the risk of aminoglycoside nephrotoxicity. This study was undertaken to evaluate the clinical usefulness of this nomogram. The nephrotoxicity risk scores of 61 patients were determined using parameters suggested by Moore et al. Thirteen patients (21%) could not be scored because their initial creatinine clearances exceeded the upper limit of the nomogram. Six patients (9.8%) developed nephrotoxicity (defined as a greater than or equal to 50% decrease in creatinine clearance). In five of these patients in whom risk scores could be determined, the scores were estimated at 14% or less. Twenty patients had risk scores of 10% or more (four patients, greater than or equal to 50%) without developing nephrotoxicity. These results demonstrate that this nomogram may have limited clinical application in predicting patients likely to develop aminoglycoside nephrotoxicity.

Adolescent↗

PubMed1978

Confirmation of a computer-derived nomogram to predict gentamicin serum concentrations in postsurgical patients.

The applicability of a previously reported nomogram to predict serum gentamicin levels in postsurgical patients was investigated. Seventeen patients accounting for 20 courses of gentamicin were studied. A total of 72 peak serum gentamicin levels were measured by a microbiological assay and compared with predicted serum levels determined by the dosing nomogram. Eighty-five percent of the measured peak gentamicin serum levels agreed with nomogram-predicted levels. This figure was reduced to 65% when certain unforeseen factors (i.e., patient interference with intravenous lines, dosage miscalculation and extra routes of gentamicin elimination) were identified. The nomogram is a particularly useful tool for the clinician to whom serum gentamicin levels are unavailable and who needs a method to predict serum gentamicin concentration based upon a given dosage.

Adult↗

PubMed1980

Analog computer monitoring and evaluation of a dosing nomogram for gentamicin based on the c'min-method: Part I.

Present methods for dosing gentamicin are based on usual doses or desired peak concentrations. The effective range is believed to be between 3 and 10 micrograms/ml. A method is proposed to maintain the minimum steady state concentration at a desired MIC with peak concentrations not exceeding 10 microgram/ml. After determination of the log serum creatinine-log creatinine clearance relationship in a specific population group (Peruvian mestizos), a nomogram for dosing gentamicin was developed. The applicability of the nomogram or the corresponding equation upon which the nomogram was based was tested in patients for desired MIC of 0.5, 1.0, 1.5 and 2.0 microgram/ml, and the actual c'min values obtained were compared with predicted levels. Using a correction factor, the nomogram is applicable for the United State and European population. The importance of drug level monitoring is emphasized.

Computers, Analog↗

PubMed1980

Analog computer monitoring and evaluation of a dosing nomogram for gentamicin based on the C'min-method, part II.

Present methods for dosing gentamicin are based on usual doses or desired peak concentrations. The effective range is believed to be between 3 and 10 micrograms/ml. A method is proposed to maintain the minimum steady state concentration at a desired MIC with peak concentrations not exceeding 10 micrograms/ml. After determination of the log serum creatinine-log creatinine clearance relationship in a specific population group (Peruvian mestizos), a nomogram for dosing gentamicin was developed. The applicability of the nomogram or the corresponding equation upon which the nomogram was based was tested in patients for desired MIC of 0.5, 1.0, 1.5 and 2.0 micrograms/ml, and the actual c'min values obtained were compared with predicted levels. Using a correction factor, the nomogram is applicable for the United States and European population. The importance of drug level monitoring is emphasized.

Adolescent↗