Measurements of central blood vessels in infants and children: Normal values

In order to provide physicians interpreting vascular radiographic studies with normal data regarding central blood vessel size in children and to facilitate the design and adaptation of intravascular devices for pediatric use, we measured lengths and diameters of central blood vessels in 141 radiographic studies in 136 children. The diameters of the following vessels were determined: right and left internal jugular veins and common carotid arteries; the inferior vena cava and the descending thoracic aorta; right and left iliac veins; and right and left femoral veins and arteries. In addition, the lengths of the inferior vena cava and the descending aorta were also determined. Blood vessel dimensions were highly correlated with age, height, weight, and body surface area. The linear regression equations for each measured dimension against age, weight, height, and surface area are provided, along with a table of predicted vessel size as a function of age.     

Respiratory function testing in infants: recommendations on normal values

The present document is being produced on behalf of the French Society of the Physiology Task Force on standards for Infant Respiratory Function Testing whose aim is to provide guidelines for good laboratory practices according to the latest international recommendations. Application of such recommendations could be of particular value when attempting to develop standardized protocols in the scope of multi-centre trials. The first part resume these recommendations about apparatus, acquisition system and software for Infant Respiratory Function Testing. The second part focuses on physiological principles and practical considerations: calibration procedure, infant conditioning, tidal breathing measurements, and occlusion techniques for assessing passive respiratory mechanics, plethysmographic measurements of lung volume and airway resistance and forced expiratory flows measurements. The major problem when collecting lung function data is that of predicted values. Valid reference data, set up according to these recommendations, are, to date, still to be established. The last part of the document provides a review of the literature concerning infant respiratory function reference data and a resume of the most used of them. This document will clearly need to be updated regularly in response to advances in knowledge in this field.     

Normal values of M mode echocardiographic measurements of more than 2000 healthy infants and children in central Europe

OBJECTIVE—To obtain normal M mode (one dimensional) echocardiographic values in a substantial sample of normal infants and children.
DESIGN—Data were obtained over three years from a single centre in central Europe.
PATIENTS—2036 healthy infants and children aged one day to 18 years.
METHODS—In line with recommendations for standardising measurements from M mode echocardiograms, and using digital echocardiographic equipment, measurements were obtained of the following: right ventricular anterior wall thickness at end diastole, right ventricular end diastolic dimension, thickness of interventricular septum at end diastole and end systole, thickness of posterior wall of the left ventricle at end diastole and end systole, left ventricular dimension at end diastole and end systole, pulmonary and aortic valve diameter, and left atrial dimension.
RESULTS—Measurements are presented graphically on centile charts with respect to body surface area, and as tables with mean and 2 SD values for newborns in relation to body weight, and for infants and children in relation to body surface area. Best fitting regression equations are given for each measured variable, using the 50th centile values.
CONCLUSION—In comparison with previously published normal values, the presented charts and tables make it possible to judge echocardiographic measurements of a particular patient as normal or abnormal.


Keywords: paediatric cardiology; echocardiography; normal values     

The median nerve evoked potential in normal children and youths: normal values]

The derivation of cortical somatosensory evoked potentials permits a good local and functional diagnosis of supratentorial structures and the localisation of damage in this area. The special diagnostical relevance of early cortical somatosensory evoked potentials as a sage, non-invasive examination method in pediatric neurology is given both by these characteristics and by the fact that they cannot, in principle, be influenced by sleep or by drugs affecting the central nervous system. Somatosensory evoked cortical potentials of N. medianus were investigated for 35 children (17 boys, 18 girls) between the ages of 6 and 17, for whom there were no anamnestic or clinical indications of neurological or otological diseases. Investigations demonstrate that the SEPs of the N. medianus from the P15 up to and including the N55, is in every case clearly measurable in children from preschool age up to the end of adolescence. In the evaluation of the cortical SEPs, the P15, N20 and P25 were considered to be the components most stable and those most valuable for clinical practice. These could also be presented with the smallest standard deviations and side differences. The latencies of the P15 and N20 of the N. medianus show significant dependencies on the height of the children. The later potential components, side differences, interpeak intervals and amplitudes show no correlations with height. The SEPs of N. medianus show no dependencies on gender or on physical parameters such as weight or head circumference of the experiments. In summary it can be established that, using the procedure mentioned above, the cortical somatosensory evoked potentials in children can be described well and reproducibly and within practical narrow standard limits.     

Disaccharidases of the small intestine mucosa in infants and children. "Normal values", log normal distribution and age dependence]

In 63 infants and children with a histological normal mucosa of the duodenum, without an isolated defect of enzyme and with a normal increase of xylose and glucose in serum after a combined xylose-lactose loading test the activities of disaccharidases were log normal distributed. The asymmetric distributions were transformed into symmetric ones and the geometric mean (x) as well as the range (+/- 2 s) of maltase, saccharase, isomaltase, lactase and trehalase were calculated. Only the activity of lactase shows a significant dependency on age. In the first year of age the lower limit (x -- 2 s) of this enzyme is much higher than later.     

Bronchodilator responsiveness in normal infants and young children

Several studies have demonstrated that normal infants exhibit bronchoconstriction after inhalation of nonspecific agonists and that the induced airway narrowing can be reversed by the inhalation of a beta-agonist. However, there are very limited data on baseline airway tone and the airway response to a beta-agonist in this subject population. The purpose of our study was to evaluate in normal infants baseline airway responsiveness to the inhaled beta-agonist, albuterol, using changes in maximal expiratory flows. Forty-one healthy infant volunteers with no history of respiratory disease or recurrent wheezing (ages 5.4 to 141.4 wk) were studied. Maximal expiratory flow- volume curves were obtained at baseline and 10 min after inhalation of albuterol (n = 28) or placebo (n = 13) using a metered-dose inhaler with a spacer. The mean percent change was significantly greater (p < 0.05) in the albuterol versus placebo group for FEV(0.5) (2.2% versus -1.5%), FEF(75%) (10.6% versus -3.1%), and FEF(85%) (12.9% versus 0.5%). Six of 28 albuterol-treated infants demonstrated increases in FEF(75%) greater than two standard deviations from the mean change in FEF(75%) seen in the placebo group. These infants were younger and more frequently exposed to maternal smoking during pregnancy. We conclude that normal healthy infants have overall levels of baseline airway tone that are similar to that reported in adults and older children; however, among the infants we evaluated the response to an inhaled bronchodilator was greatest in the youngest infants and in those exposed to tobacco smoking. Keywords: airway responsiveness; asthma; tobacco smoke; infant pulmonary function; bronchodilator     

Zinc status in normal Thai infants and children

Serum zinc levels in Thai infants and children from newborn to 14 years were studied. Data showed that serum zinc levels of infants were significantly lower than that of children (P less than 0.0005) although serum zinc levels in infants were low. They appeared to have normal growth and development. Beyond one year of age serum zinc levels increased with increasing age and there was no reduction in serum zinc level in pubertal subjects. Serum retinol binding protein was also studied. It was found to be low at birth and started to increased in the age of 1--5 months, the relationship between serum zinc and serum RBP was not apparent either in the younger age groups or in adult population.     

Distinguishing lymphatics from blood vessels in normal and diseased skin

If it were true that lymphatics are essential for the removal of macromolecules and in this way the oncotic and hydrostatic pressures within the interstitium are determined; if it were true that lymphatics are the principal pathway for the exit of antigen and of macrophages and hence, important for cell mediated immunity, then on both accounts the lymphatics are of great significance. There must be some anxiety that none of this can be confirmed and that some tissues such as the brain and the eye do not need lymphatic vessels as such. We must also note that in many diseases the lymphatic system seems to be severely disrupted, and yet it is difficult to show that the tissues are severely compromised. One wonders to what extent blood vessels or any other system, such as the mononuclear phagocytic system, can take over the role of the lymphatic. To answer these questions one needs to be able to identify the lymph clearance system as distinct from the blood supply system. Although this is easy in health, it becomes very difficult in disease.     

Nasal NO: normal values in children age 6 through to 17 years.

The present study is an assessment of normal values of nasal nitric oxide (nNO) in healthy children. Healthy children aged between 6-17 yrs were recruited from three schools in Rotterdam (The Netherlands). Breath was held for 10 s, while air was extracted from one nostril at 700 mL.min(-1). The mean nNO value at the response plateau after 7-10 s was recorded and the average of three measurements was used. In total, 340 children participated; the male:female ratio was 156:184. Three reliable measurements were available in 85% of the children. The nNO concentrations were distributed normally (mean 449 ppb, SD 115). They were not associated with sex, passive smoking or body mass index. In children aged <12 yrs nNO correlated positively with age, history of adenoidectomy and ambient NO. In children aged > or =12 yrs ambient NO was the only significant modifier. Prediction rules for nNO values in children were formulated. In conclusion, the current study presents normal values for nasal nitric oxide in children, which can be used to assess the value of nasal nitric oxide in respiratory illnesses.     

Measurements of interrupter resistance: reference values for children 3-13 yrs of age.

The interrupter technique is a convenient and sensitive technique for studying airway function in subjects who cannot actively participate in (forced) ventilatory function tests. Reference values for preschool children exist but are lacking for children >7 yrs. Reference values were obtained for expiratory interrupter resistance (R(int,e)) in 208 healthy Dutch Caucasian children 3-13 yrs of age. A curvilinear relationship between R(int,e) and height was observed, similar to published airways resistance data measured by plethysmography. No significant differences in cross-sectional trend or level of R(int,e) were observed according to sex. It was found that Z-scores could be used to express individual R(int,e) values and to describe intra- and interindividual differences based on the reference equation: 10logR(int,e)=0.645-0.00668x standing height (cm) kPa x L(-1) x s(-1) and residual SD (0.093 kPa x L(-1) x s(-1)). Expiratory interrupter resistance provides a tool for clinical and epidemiological assessment of airway function in a large age range.     

Plasma free amino acid values in normal children and adolescents

We measured plasma free amino acids in 52 children (mean age 8 years) and 80 adolescents (mean age 16 years); conditions of diet and time of day were similar in the two groups. The protocols allowed us to compare their interindividual variation with values previously reported by us for adults. In children, the values for all but seven amino acids were normally distributed; in adolescents there were only six exceptions. Effects of age were apparent: values for only two amino acids were higher in children than adolescents. Values were significantly lower for ten amino acids in children v adolescents and for 11 amino acids in younger children (1 to 6 years) v older children (7 to 12 years). An effect of sex was apparent for five amino acids in adolescents; such differences were not apparent in children. All differences were quasicontinuous and occurred within the global distributions that define values for plasma amino acids in normal children and adolescents. Two artifacts (choice of anticoagulant and delay in deproteinization) affected values for taurine and cystine, respectively.     

What are normal blood values for leukemia in remission

1. The values for hemoglobin concentration, total white blood cells, granulocytes, lymphocytes and monocytes at the midpoint of 78 drug-induced remissions in a group of children with acute leukemia have been presented. Thesevalues have been compared with those from a group of normal children, andthe differences analyzed statistically.

2. Statistical analysis shows that, in general, blood values in remission arereduced by the particular agent employed. White blood cells are more markedly affected than hemoglobin.

3. The effects are essentially the same with 6-M.P. given alone or in combination with azaserine or DON.

4. The reduction in values is greatest with 6-M.P., alone or in combination,less with amethopterin and least with prednisone.

5. The data presented indicate that criteria for complete blood remissionshould make allowances for the influence of the drug employed.

Submitted on June 12, 1958 Accepted on August 10, 1958     

The tibial evoked potential in healthy children and adolescents: normal values]

The somatosensory evoked cortical potentials were investigated for 35 healthy children (17 boys, 18 girls) between 6 and 17. The stimulation of the N. tibialis was affected at the Malleolus medialis using surface electrodes; the derivation was likewise conducted according to the ten-twenty system using surface electrodes. Investigations carried out employing this methodology demonstrate that the SEP's of the N. tibialis from the N30 to the N70 are clearly measurable in the children. The N30, P40 and N50 could be presented with the smallest standard deviations and side differences. The latencies of N30 and P40 show significant dependencies on the height of the children. Influence of gender could be demonstrated more for the latency of the N30 in from of longer latencies in boys that in girls which were independent of body size.     

Bruce treadmill test in children: normal values in a clinic population

The Bruce treadmill protocol is suitable for children as young as age 4 years. Maximal endurance time may be used as the sole criterion of exercise capacity, and normal values were established with 327 children having an innocent heart murmur. Mean endurance time in boys increased from 10.4 minutes at age 4 to 5 years, to 14.1 minutes at age 13 to 15 years. Mean endurance time in girls increased from 9.5 minutes at age 4 to 5 years to 12.3 minutes at age 10 to 12 years. Mean maximal heart rate ranged from 193 to 206 beats/min. Age differences in mean maximal and submaximal heart rates were small. There were negative correlations between endurance time and the ratio of weight to height. There were negative correlations between heart rates at treadmill stages 1 to 3 and the endurance times. The correlation coefficient of endurance time with maximal oxygen uptake was 0.88, but for clinical purposes endurance time alone is a satisfactory indicator of exercise performance.