Body surface area estimation: Cross validation of several prediction equations.

Background Body surface area (BSA) is used in clinical practice to prescribe medication, standardize measured parameters etc. Normogram has been the gold standard. However, there are several prediction equations in the published literature. A simple method giving an accurate estimation would help to assess BSA in day to day clinical practice efficiently. Objective To assess the accuracy of different equations for the estimation of BSA in a group of Sri Lankan children. Method Data collected in 3 different school surveys carried out between 2002 and 2005 were used. BSA estimated by 9 prediction equations described in the literature were compared with the BSA assessed by normogram. Results Two thousand three hundred and thirty eight girls and 639 boys, between the ages of 5-16 years, were assessed. The mean ages of the boys and girls were 10.3±1.47 years and 11.5±2.47 years respectively. The highest mean BSA estimation was given by Gehan & George equation (boys 1.14±0.20m2 and girls 1.2 ± 0.25m2) and lowest by Yu et al (boys 1.08±0.20m2 and girls 1.13±0.25m2). Estimates correlated highly with BSA assessed by normogram. When the estimates were compared with normogram, equation of Mattar gave the highest bias for both groups (females 0.0152m2 and males 0.0177m2). Mosteller equation gave relatively low bias (females 0.0077m2, and males 0.0072 m2). Conclusions All equations gave very good agreement between each other. Out of the equations, easiest to use in day to day clinical practice is the equation described by Mosteller. The maximum bias in estimation would lead to less than 5% error in determining drug doses which is negligible in day to day clinical practice. Mosteller equation is suitable for routine clinical use.

Assessment of body composition in Sri Lankan children: validation of a skin fold thickness equation.

BACKGROUND: Morbidity associated with obesity is related to the fat mass (FM) of the body. The direct estimation of FM is difficult. Skin fold thickness (SFT) is a simple and cheap alternative for accurate assessment of FM, and population specific equations are necessary for accurate assessment of FM using SFT. OBJECTIVE: To develop a SFT prediction equation to estimate FM of Sri Lankan children. DESIGN, SETTING AND METHOD: Across-sectional descriptive study was done at the University Paediatric Unit of Lady Ridgeway Hospital, Colombo. Data were collected from 5 to 15 year old healthy children. Triceps, biceps, supra-iliac and subscapular SFT were measured using Harpendens skin fold caliper. Total body water was assessed using an isotope dilution method (D2O), and fat free mass calculated. FM was assessed based on 2 compartment body composition model. Multiple regression analysis was used to develop prediction equation and validated using PRESS (prediction of sum of squares) statistical technique. Independent variables were age, triceps SFT, subscapular SFT and sex. RESULTS: Prediction equation for FM [(0.68 x age) + (0.246 x triceps SFT) + (0.383 x subscapular SFT) - (1.61 x sex code) -3.45] was able to predict 76.4% of variance with a root mean squared error (RMSE) of 3.4 kg. PRESS statistics was 3.4 kg with press residuals of 1.56 kg. Bland-Altman technique showed that the majority of the residuals were within mean bias +/-1.96 SD. CONCLUSION: Results of this study provide an SFT equation for the prediction of FM in Sri Lankan children.

Fulminant hepatic failure and paracetamol overuse with therapeutic intent in febrile children.

OBJECTIVE: To evaluate the risk of fulminant hepatic failure in relation to paracetamol overuse with therapeutic intent in febrile children. METHODS: It was a case control study. Paracetamol ingestion for the current febrile illness was compared between 25 cases of fulminant hepatic failure and 33 hospital age matched controls. RESULTS: Supra-therapeutic doses of paracetamol (mean 145 mg/kg/day) were consumed by all 25 cases compared to none in the control group. Mean paracetamol level in the cases and controls were, respectively, 26.84 mg /dl and 0.051 mg /dl (p< 0.001). The mean duration of paracetamol intake prior to admission in cases was 3. 45 days compared to 1.85 days in the control group. Nineteen, 5 and 3 were, respectively, graded as hepatic encephalopathy grade 1, 2 and 3. All six patients in grade 2 and 3 had hepatomegaly compared to 78% in the grade 1. Four had jaundice and all were in grade 2 or 3. Mean alanine aminotransferase was 2781 U/L None of the randomly selected cases (6) had serological evidence of Hepatitis A, Hepatitis B or Dengue. Three cases died. CONCLUSION: Exposure to multiple supratherapeutic doses of paracetamol is a risk factor to develop fulminant hepatic failure in children with an acute viral like febrile illness.

Nutritional status of schoolchildren in an urban area of Sri Lanka.

BACKGROUND: As in many other Asian countries, Sri Lanka is in the phase of a rapid demographic, nutritional and epidemiological transition. As a result dietary habits and lifestyle are changing. These have led to new health problems in the region. Childhood overweight and obesity are examples of such problems. OBJECTIVE: To provide information on the nutritional status of 8-12 years old schoolchildren in an urban area of Sri Lanka. SUBJECTS AND METHODS: Seven schools situated in the city of Colombo were randomly selected. They showed a fair representation of children of all social levels. Fifty students from each grade (years 4, 5, 6, 7) of each school were randomly selected. Their height was measured using a stadiometer to the closest 0.1cm and weight measured using an electronic weighing scale (Seca, France) to the closest 100 g. Calibration was checked with a standard weight at each 25 measurements. Information regarding behaviour, feeding practices and socioeconomic factors were obtained by a questionnaire filled by the parent or the guardian. To define obesity and overweight, sex and age specific body mass index (BMI) criteria recommended by the International Obesity Task Force (IOTF) were used. The age and sex specific BMI 5th percentile from revised NCHS (2000) growth charts were used to define thinness. Weight and height Z score of less than -2 from the median of height for age and weight for age derived using the ANTHRO software (CDC, USA) were used to define stunting and underweight respectively. Data were analysed using Epilnfo 2000 (CDC, USA) computer package. RESULTS: Anthropometric data of 1 224 children (48% boys), and feeding practices and behaviour pattern data of 1 102 children (44% boys) were analysed. Obesity prevalence among boys (4.3%) was higher than in girls (3.1%). The prevalence of thinness was 24.7% in boys and 23.1% in girls. 5.1% of boys and 5.2% of girls were stunted. 7.0% of boys and 6.8% of girls were underweight. 66% of obese children and 43.5% of overweight children belonged to high-income category (monthly family income more than Rs. 20,000). Apart from family income, behaviour patterns did not significantly influence the nutritional status. CONCLUSIONS: Although the data are not representative of the entire country, nutritional transition is evident in the city of Colombo. Obesity and overweight in older children are some emerging nutritional problems that may be the consequence of emerging patterns of the lifestyle and diet in response to social and cultural changes.

Ecchymoses: an unusual manifestation of toxocariasis in children.

OBJECTIVE: To investigate the aetiology of multiple ecchymoses associated with eosinophilia. SETTING: Professorial Paediatric Unit (PPU) at Lady Ridgeway Hospital (LRH) for children, Colombo. DESIGN: Prospective study from July 1998 to April 2000. MATERIALS AND METHODS: Patients admitted to the PPU with multiple ecchymoses associated with an absolute eosinophilia (> 1 x 10(9)/1) were investigated further to determine the possible aetiology; bleeding time, clotting time, platelet count, platelet function tests, stools examination and toxocara antibody tests were performed. Patients who were positive for toxocara were treated either with thiabendazole or albendazole. Patients who had geohelminth infestations were treated with mebendazole. RESULTS: 14 children (11 boys) were studied. 7 were between 1 and 5 years, and 7 were above 5 years of age. The mean eosinophil count was 4.3 x 10(9)/1. All patients had a prolonged bleeding time, but clotting time and platelet counts (mean value 220 x 10(9)/1) were normal. Platelet function tests were done in 5 patients. Twelve patients were positive for toxocariasis and the other 2 were positive for ascariasis. All children who were positive for toxocariasis had contact with pet cats or dogs. Six patients were treated with thiabendazole and 6 with albendazole. The two patients who had ascariasis were treated with mebendazole. Post-treatment mean eosinophil count was 0.63 x 10(9)/1, and the bleeding time was 4 minutes. CONCLUSION: Toxocariasis could present with ecchymoses due to an acquired bleeding disorder. Awareness of this would help to investigate, diagnose and treat early, and lessen parental anxiety.

Cerebral thrombosis in beta-thalassaemia major.

Two patients with homozygous beta thalassaemia complicated by cerebral thrombosis are reported. An alteration in coagulability due to a sudden increase in haematocrit and platelets was the probable cause in one patient. Although the other patient had many complications of thalassaemia, the cause for cerebral thrombosis was not identifiable.

Prospective study of congenital heart disease in children.

OBJECTIVE: Descriptive analysis of patients with congenital heart disease. DESIGN: Prospective study. SETTING: Professorial Paediatric Unit, Lady Ridgeway Hospital, Colombo 8. METHOD: All patients with congenital heart disease (CHD) admitted to the Professorial Paediatric Unit at Lady Ridgeway Hospital from August 1998 to August 1999 were included in this study. Data were collected using a pretested questionnaire which was filled by one of the authors. Patients were followed up to date. RESULTS: 102 patients, 53 (52.0%) males with congenital heart disease were studied. All patients were evaluated with chest xray, ECG and 2 D echocardiography, except for two. Based on clinical and echocardiographic findings 69 (67.6%) were found to have acyanotic and 33 (32.4%) cyanotic heart disease; 22 (21.5%) had a ventricular septal defect. Tetralogy of Fallot was diagnosed in 10 (9.8%) patients and was the commonest cyanotic CHD. 52 (51.0%) cases were detected between the ages of 2 weeks to 12 months, and 39 (38.2%) were detected routinely at the postnatal examination of the newborn. Only 12 (11.7%) patients underwent corrective surgery, 10 in Sri Lanka, and 2 in India. 19 children died during the study period, a case fatality of 18.6%. CONCLUSIONS: Previous studies have shown that congenital heart disease accounted for between 16% to 30% of deaths in the Professorial Paediatric Unit at LRH. This is the second commonest cause of deaths in the unit. This study has revealed a high case fatality rate among the patients awaiting corrective surgery. Unless surgical care for patients with congenital heart disease in the public sector are improved, many such children will continue to die early due to lack of facilities.