The clinical implications of body surface area as a poor proxy for cardiac output

Renal plasma flow, glomerular filtration rate, and cardiac output are traditionally indexed for body surface area by expressing these traits as per-surface-area ratios. Indexing is intended to remove interindividual variation attributable to differences in body size. Regression is an alternative method commonly used to adjust other biological traits for the effects of a covariate, such as body surface area. The purpose of this study was to compare the indexing and regression methods of adjusting renal plasma flow, glomerular filtration rate, and cardiac output for interindividual differences in body surface area. We estimated renal plasma flow by the clearance of p-aminohippurate, glomerular filtration rate by clearance of inulin, and cardiac output by thoracic electrical impedance in a sample of 78 unrelated females and 78 unrelated males (ages 20-49.9 yr) from the general population of Rochester, MN. The indexing method created negative dependencies of renal plasma flow and cardiac output on body surface area and failed to eliminate the positive dependency of glomerular filtration rate on body surface area. Moreover, indexing obscured differences in mean renal plasma flow between females and males and created differences in mean cardiac output between the genders. In contrast, the regression method consistently eliminated dependencies of each trait on body surface area and did not lead to inappropriate inferences about mean differences in these traits between females and males. We conclude that the indexing method of adjusting renal plasma flow, glomerular filtration rate, and cardiac output for interindividual differences in body surface area should be abandoned and replaced by use of the regression method.

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SYSTEMIC BLOOD FLOW IN INFANTS AND CHILDREN WITH AND WITHOUT HEART DISEASE

PEDIATRICS ◽

10.1542/peds.32.2.186 ◽

1963 ◽

Vol 32 (2) ◽

pp. 186-201

Author(s):

Glen G. Cayler ◽

Abraham M. Rudolph ◽

Alexander S. Nadas

Keyword(s):

Cardiac Output ◽

Heart Disease ◽

Cardiac Index ◽

Surface Area ◽

Body Surface Area ◽

Body Surface ◽

Close Correlation ◽

Significant Difference ◽

Normal Increase ◽

Response To Exercise

A technique for measuring cardiac output by the Fick method in small infants during cardiac catheterization is described. Data on resting oxygen consumption, arteriovenous oxygen difference and systemic cardiac output is presented for a group of 126 subjects composed mainly of infants and young children with congenital heart disease. It was found that (a) there was no significant difference in mean resting cardiac index for patients with body surface area under 1.0 square meter regardless of the presence of, or the severity of, heart disease, and (b) patients with heart disease who were larger than 1.0 square meter had significantly lower mean cardiac indices and higher arteriovenous oxygen differences than the control patients. An excellent linear correlation of cardiac output to body surface area was found. There was also a close correlation between index and regression lines for cardiac output leading support to the validity of the cardiac index concept for comparing cardiac outputs in various sized patients. The normal increase in cardiac output during exercise is greater for children than for adults. Forty-seven per cent (8 of 17) children with heart disease showed low cardiac output response to exercise.

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Normalized Left Ventricular Volumes and Function in Thalassemia Major Patients with Normal Myocardial Iron.

Blood ◽

10.1182/blood.v106.11.2707.2707 ◽

2005 ◽

Vol 106 (11) ◽

pp. 2707-2707

Author(s):

Mark A. Westwood ◽

Lisa J. Anderson ◽

Alicia M. Maceira ◽

Emma Prescott ◽

John B. Porter ◽

...

Keyword(s):

Cardiac Output ◽

Ejection Fraction ◽

Surface Area ◽

Body Surface Area ◽

Body Surface ◽

Left Ventricular ◽

Volume Index ◽

Iron Loading ◽

Myocardial Iron ◽

End Diastolic Volume

Abstract Repeated blood transfusions in Thalassemia Major (TM) may lead to myocardial iron accumulation and death. Left ventricular (LV) function is commonly used to assess for iron overload, however, the reference range in TM for these variables in the absence of myocardial iron loading is not known. We used cardiovascular magnetic resonance (CMR) in 205 TM patients and studied those (N=81) with normal myocardial T2* measurements (T2*>20ms) and by inference without excess myocardial iron. Resting LV volumes and function normalized to body surface area were compared with 40 age and gender matched healthy controls. All LV parameters were significantly different (p<0.05) in TM patients (see tables 1 and 2). The lower limit for ejection fraction was higher in TM (males 59 vs 55%, females 63 vs 59%, both P<0.001). The upper limit for end-diastolic volume index was higher in TM (males 152 vs 105 mL/m2, females 121 vs 99 mL/m2, both P<0.05). In TM the cardiac output index (P<0.001) was increased. In conclusion, at rest TM patients with normal myocardial T2* values and no excess myocardial iron loading have a hyperdynamic circulation and substantially different values for LV parameters compared with controls. Significant misdiagnosis of cardiomyopathy will result from comparison of TM patients with normal ranges. LV Parameters Normalized to Body Surface Area in Males. TM Patients (Mean±SD) Controls (Mean±SD) LV parameters normalized to body surface area for males with mean and standard deviations divided into TM patients with no myocardial iron loading and non-anemic age matched controls. The ejection fraction is not indexed to body surface area as it does not vary significantly with body habitus. LVEDVI - left ventricular end-diastolic volume index, LVESVI - left ventricular end-systolic volume index, LVSVI - left ventricular stroke volume index, LVEF - left ventricular ejection fraction, LVMI - left ventricular mass index, CO - cardiac output, COI cardiac output index. LVEDVI (mL/m 2 ) 97.2±27.2 84.1±10.5 LVESVI (mL/m 2 ) 23.1±5.2 29.6±6.1 LVSVI (mL/m 2 ) 70.8±15.8 54.4±7.1 LVEF 71.0±6.1 64.9±5.0 LVMI (g/m 2 ) 84.6±20.3 75.0±8.4 CO (L/min) 9.8±3.2 6.8±1.5 COI (L/min/m 2 ) 5.7±1.9 3.5±0.7 LV Parameters Normailzed to Body Surface Area in Females TM Patients (Mean±SD) Controls (Mean±SD) LV parameters normalized to body surface area for females with mean and standard deviations divided into TM patients with no myocardial iron loading and non-anemic age matched controls. The ejection fraction is not indexed to body surface area as it does not vary significantly with body habitus. LVEDVI - left ventricular end-diastolic volume index, LVESVI - left ventricular end-systolic volume index, LVSVI - left ventricular stroke volume index, LVEF - left ventricular ejection fraction, LVMI - left ventricular mass index, CO - cardiac output, COI cardiac output index. LVEDVI (mL/m 2 ) 87.4±16.6 79.4±9.8 LVESVI (mL/m 2 ) 20.8±7.3 26.1±4.7 LVSVI (mL/m 2 ) 66.5±12.4 53.3±7.3 LVEF 75.1±5.9 67.1±4.3 LVMI (g/m 2 ) 69.9±17.3 61.9±7.9 CO (L/min) 8.2±2.0 5.8±1.6 COI (L/min/m 2 ) 5.2±1.3 3.4±0.8

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Cardiac output in normal resting man

Journal of Applied Physiology ◽

10.1152/jappl.1961.16.2.276 ◽

1961 ◽

Vol 16 (2) ◽

pp. 276-278 ◽

Cited By ~ 49

Author(s):

John T. Reeves ◽

Robert F. Grover ◽

Giles F. Filley ◽

S. Gilbert Blount

Keyword(s):

Cardiac Output ◽

Oxygen Uptake ◽

Metabolic Rate ◽

Surface Area ◽

Body Surface Area ◽

Body Surface ◽

Normal Blood Flow ◽

Pulmonary Arterial ◽

The Mean ◽

Oxygen Difference

Sixty-three measurements of cardiac output in 50 normal resting individuals utilizing pulmonary arterial catheterization and the classical Fick method were made to investigate the normal standards of cardiac output under these conditions. Variation between individuals in age, sex, body size and metabolic rate was great enough to render the cardiac index (cardiac output/ unit of body surface area) a rather insensitive standard of normal blood flow. Rather the variation was substantially improved by considering cardiac output to be linearly related to oxygen uptake. This direct relationship appeared to be the result of the A-V oxygen difference varying independently of oxygen uptake, metabolic rate and body surface area. The mean A-V oxygen difference was 39.8 cc/l. with one standard deviation of α5.8 cc/l. Submitted on August 8, 1960

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Differences in pressure sensitivity and tactile discrimination among individuals as a function of gender and body surface area

PsycEXTRA Dataset ◽

10.1037/e527352012-548 ◽

2006 ◽

Author(s):

Somer M. Givens ◽

David B. Boles

Keyword(s):

Surface Area ◽

Body Surface Area ◽

Body Surface ◽

Pressure Sensitivity ◽

Tactile Discrimination

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Risk Factors for Bleeding during Treatment of Acute Venous Thromboembolism

Thrombosis and Haemostasis ◽

10.1055/s-0038-1650643 ◽

1996 ◽

Vol 76 (05) ◽

pp. 682-688 ◽

Cited By ~ 33

Author(s):

Jos P J Wester ◽

Harold W de Valk ◽

Karel H Nieuwenhuis ◽

Catherine B Brouwer ◽

Yolanda van der Graaf ◽

...

Keyword(s):

Risk Factors ◽

Venous Thromboembolism ◽

Surface Area ◽

Body Surface Area ◽

Body Surface ◽

Small Body ◽

Bleeding Risk ◽

Risk Scores ◽

Risk Of Bleeding ◽

Acute Venous Thromboembolism

Summary Objective: Identification of risk factors for bleeding and prospective evaluation of two bleeding risk scores in the treatment of acute venous thromboembolism. Design: Secondary analysis of a prospective, randomized, assessor-blind, multicenter clinical trial. Setting: One university and 2 regional teaching hospitals. Patients: 188 patients treated with heparin or danaparoid for acute venous thromboembolism. Measurements: The presenting clinical features, the doses of the drugs, and the anticoagulant responses were analyzed using univariate and multivariate logistic regression analysis in order to evaluate prognostic factors for bleeding. In addition, the recently developed Utrecht bleeding risk score and Landefeld bleeding risk index were evaluated prospectively. Results: Major bleeding occurred in 4 patients (2.1%) and minor bleeding in 101 patients (53.7%). For all (major and minor combined) bleeding, body surface area ≤2 m2 (odds ratio 2.3, 95% Cl 1.2-4.4; p = 0.01), and malignancy (odds ratio 2.4, 95% Cl 1.1-4.9; p = 0.02) were confirmed to be independent risk factors. An increased treatment-related risk of bleeding was observed in patients treated with high doses of heparin, independent of the concomitant activated partial thromboplastin time ratios. Both bleeding risk scores had low diagnostic value for bleeding in this sample of mainly minor bleeders. Conclusions: A small body surface area and malignancy were associated with a higher frequency of bleeding. The bleeding risk scores merely offer the clinician a general estimation of the risk of bleeding. In patients with a small body surface area or in patients with malignancy, it may be of interest to study whether limited dose reduction of the anticoagulant drug may cause less bleeding without affecting efficacy.

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The use of Body Surface Index as a Better Clinical Health indicators Compare to Body Mass Index and Body Surface Area for Clinical Application

International Journal of Scientific Research in Science Engineering and Technology ◽

10.32628/ijsrset2184117 ◽

2018 ◽

pp. 131-136

Author(s):

Shirazu I. ◽

Theophilus. A. Sackey ◽

Elvis K. Tiburu ◽

Mensah Y. B. ◽

Forson A.

Keyword(s):

Surface Area ◽

Body Surface Area ◽

Clinical Application ◽

Body Surface ◽

Body Height ◽

Health Indicators ◽

The Body ◽

Body Parameters ◽

The Relationship ◽

Individual Body

The relationship between body height and body weight has been described by using various terms. Notable among them is the body mass index, body surface area, body shape index and body surface index. In clinical setting the first descriptive parameter is the BMI scale, which provides information about whether an individual body weight is proportionate to the body height. Since the development of BMI, two other body parameters have been developed in an attempt to determine the relationship between body height and weight. These are the body surface area (BSA) and body surface index (BSI). Generally, these body parameters are described as clinical health indicators that described how healthy an individual body response to the other internal organs. The aim of the study is to discuss the use of BSI as a better clinical health indicator for preclinical assessment of body-organ/tissue relationship. Hence organ health condition as against other body composition. In addition the study is `also to determine the best body parameter the best predict other parameters for clinical application. The model parameters are presented as; modeled height and weight; modelled BSI and BSA, BSI and BMI and modeled BSA and BMI. The models are presented as clinical application software for comfortable working process and designed as GUI and CAD for use in clinical application.

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