Body Surface Area Calculation Research Articles

Thermal Significance of the Topographical Distribution of Blubber in Ringed Seals (Phoca hispida)

The distribution of blubber in ringed seals (Phoca hispida) and relationships between surface area, body mass, and linear dimensions are described. The blubber was distributed in such a way that the ratio of blubber thickness to body radius is nearly constant over the body, maximizing the available blubber for insulation. The hind part of the body has a higher thickness to radius ratio and is thus "overinsulated." During periods of mass loss, fat is lost fastest from this overinsulated region, thus reducing the negative thermal effects of the fat loss. We present formulae for calculating body surface area and an effective, or "equivalent blubber thickness," for calculations of heat loss and suggest that these formulae are independent of size and shape. By combining these equations, we arrive at a general formula for calculating a lower limit for heat loss from marine mammals. According to this formula, thermal stability can be maintained when blubber is lost if mass is simultaneously lost from the body core.

Bedside calculation of body surface area for infants and children.

In 179 healthy boys and girls, the relationship between body surface area (S) in dm2 and body weight (bw) in kg was investigated. The body surface was calculated from the DuBois and DuBois formula. For infants below 20 kg, the relationship followed the regression equation S=3.6kg + 9; r=0.996. For infants with bw between 20-40 kg, the regression equation S=2.5.kg + 33; r=0.977 was found. These equations can easily be memorized and may be able to replace nomograms when bedside calculations of the S is required. In addition, formulas for the volume of plasma expander to be used in the prophylaxis and treatment of shock, trauma, and burn injuries are presented.

Life-threatening neuropathy and hepatotoxicity in infants during induction therapy for acute lymphoblastic leukemia

I N D U C T t O N of a hematologic remission is now achieved in nearly 95% of cases of acute lymphoblastic leukemia by using a standard combination Of a vinca alkaloid (vincristine), prednisone , and a third agent, usually L-asparaginase o r adriamycin. 1 Toxicity is minimal and represents less than 1% of deaths during induction? The doses of these agents, based on a body surface area calculation, have been determined through extensive clinical testing utilizing both children and adults. Two young patients developed life-threatening neuropathy and hepatotoxicity after administration of this standard ALL chemotherapy regimen. A retrospective review of all infants with ALL seen at the University of Minnesota Hospitals over a two-year period Was then performed to determine if the profound toxicity observed in the two patients had been seen in other young children receiving induction therapy for ALL. The results of this review suggest that the accepted doses of chemotherapeutic agents used for ALL induction therapy in infants, especially vincristine, are excessive and that unacceptable toxicity may occur. CASE REPORTS Patient l, A 16-month-old girl weighing 10.1 kg, with a BSA of 0.47 m ~, was diagnosed as having ALL. Treatment was begun with vincristine 1.5 mg/m ~ weekly, which equaled 0.07 mg/kg; prednisone 40 mg/m ~ daily; and L-asparaginase 6,000 IU/m ~ three times per week for 28 daysl as well as methotrexate every two weeks intrathecally. On day 27, the patient was unable to move and had mouth sores, ileus, massive hepatosplenomegaly, and flaccid paralysis. An electromyogram revealed decreased muscle responsiveness to nerve stimulation, consistent with vincristine-induced axonal neuropathy. Because of progressive hepatic deterioration, a liver biopsy was performed; histologic examination showed diffuse severe fatty changes of hepatocytes, focal hepatocellular necrosis, a s evidenced by Small collections of neutrophils in the lobules, and a mild acute inflammatory cell infiltrate with minimal increase in fibrous tissue in the triads. Cholestasis was also present, but there was no evidence o[ viral inclusions. The biopsy was considered to be most consistent with drug-induced hepatotoxicity. After four weeks and a precarious

Human thyroid growth. A scan study. (Preliminary report).

In patients up to 19 years old, the scan surface area and average length of the thyroid were plotted as a function of age, height, weight and calculated body surface area. On an average, the right thyroid lobe was longer than the left. There was good correlation between the mean length of the thyroid gland and the patient's age or height. The correlation was slightly less satisfactory with the patient's calculated surface area (in part this may be because some patients were over- or underweight). The plot of thyroid length versus weight of the patient showed a distinct bend, as though approaching an asymptote. With the assumption that this might be approximated as a rectangular hyperbola, replotting was done in terms of the reciprocal of thyroid length as a function of the reciprocal of the patient's weight. There was a highly significant correlation. The bend in the curve of thyroid length versus weight was tentatively related to the increased body weight that occurs at about age 9 years. In these normal children, there was an excellent correlation between the scan surface area of the thyroid and mean thyroid length (δ = 0.84). Plots of the scan surface area of the thyroid versus age, patient height, patient weight of the patient's surface area, gave a less satisfactory result than corresponding plots based on the thyroid length. The formula for thyroid length versus age can be combined with the data of Kay and co-workers to yield an equation which describes thyroid weight in children as a function of thyroid scan length.

Radiologic estimation of heart volume. A valuable diagnostic tool.

Heart size can be determined by a simple radiologic method here described. The method, widely used in Europe, depends on 3 measurements made on standard posteroanterior and lateral chest films at focal distances from 150 to 200 cm. The heart volume is calculated by slide rule from these data. Correlations of radiologically determined heart volume with other anatomic and physiological variants, such as calculated body surface area, total hemoglobin content, and physical working capacity, provide indices for recognizing cardiac enlargement and other cardiophysiologic abnormalities. This method has theoretical and practical advantages, and the author believes it to be the most uniform and precise plan for utilizing rediologic data for serial determinations of heart size.

Indirect estimation of body surface area and volume.

A convenient and rapid photographic technique of obtaining data which can be used for the calculation of human body surface area is described. The results, which are in good agreement with values obtained by a reliable method of readings from a chart, provide additional support for the application of the increasingly important photographic method of quantitation in human biology. Data have also been obtained which suggest that the surface area of dogs may satisfactorily be estimated by the same previously reported chart method used for human beings. Empirical equations for the calculation of body volume (and density) in man, based essentially on measurements of weight and height, have been developed and tested in respect to measured values obtainable from the literature. Statistical evaluation and the criteria of convenience and rapidity in use, rather than more restrictive theoretical considerations, indicate the superiority of predominantly empirical relationships as the methods of choice for the prediction of body volume. Comparison of the reliability of the results with those obtainable by established methods of quantitation indicates that these equations may be useful as approximate, but most convenient indices of gross body composition. Submitted on April 1, 1959

Cineplastic muscle motors for prostheses of arm amputees.

1. No significant difference was found in the vital-capacity quotients of subjects in the sitting and in the standing position. 2. The loss of height that might be present in a scoliotic patient as the result of the lateral curvature of the spine does not produce enough change in the calculated body surface area of that patient to cause significant changes in the vital-capacity quotient. 3. Subjects with extensive respiratory-muscle paralysis and with a history of having been treated in respirators exhibited vital-capacity quotients significantly lower than those found in normal controls for their age and sex. 4. There was no significant difference in the vital-capacity quotients between normal and non-scoliotic, non-respiratory poliomyelitic male and female subjects. 5. There was no significant difference in the vital-capacity quotients between normal and poliomyelitic scoliotic subjects when the degree of deformity was slight or moderate. However, in severe scoliosis an appreciable reduction in vital-capacity quotients was observed. 6. Non-poliomyelitic scoliotic subjects with either thoracolumbar, primary lumbar, primary thoracic, or primary double curve patterns with angular deformities of less than 45 degrees were found to have vital-capacity quotients which were within normal limits. A significant reduction in vital capacity was found in subjects with the thoracic pattern when the angular deformity exceeded 45 degrees.

COMPARISON OF VITAL CAPACITY IN NORMAL AND POLIOMYELITIC SUBJECTS

1. No significant difference was found in the vital-capacity quotients of subjects in the sitting and in the standing position. 2. The loss of height that might be present in a scoliotic patient as the result of the lateral curvature of the spine does not produce enough change in the calculated body surface area of that patient to cause significant changes in the vital-capacity quotient. 3. Subjects with extensive respiratory-muscle paralysis and with a history of having been treated in respirators exhibited vital-capacity quotients significantly lower than those found in normal controls for their age and sex. 4. There was no significant difference in the vital-capacity quotients between normal and non-scoliotic, non-respiratory poliomyelitic male and female subjects. 5. There was no significant difference in the vital-capacity quotients between normal and poliomyelitic scoliotic subjects when the degree of deformity was slight or moderate. However, in severe scoliosis an appreciable reduction in vital-capacity quotients was observed. 6. Non-poliomyelitic scoliotic subjects with either thoracolumbar, primary lumbar, primary thoracic, or primary double curve patterns with angular deformities of less than 45 degrees were found to have vital-capacity quotients which were within normal limits. A significant reduction in vital capacity was found in subjects with the thoracic pattern when the angular deformity exceeded 45 degrees.