Th1 and th2 cytokine expression in nasopharyngeal secretions during acute bronchiolitis in children younger than two years old.

OBJECTIVES: We characterised the T helper cytokine profiles on the surface of nasal mucosa of children with acute bronchiolitis caused by Respiratory Syncytial Virus, Parainfluenza Virus, Influenza Virus, Adenovirus, or without any viral identification, in order to examine whether these viral types modified cytokine responses. As an additional objective we sought to determine if T helper polarisation was associated with other demographic and environmental factors. METHODS: A prospective study of children with acute bronchiolitis was performed. Patients were recruited from the emergency department of a central hospital in Lisbon, Portugal. Demographical, epidemiological and clinical data were gathered from a questionnaire. Nasal swabs were collected for viral studies (immunofluorescence) and T cell cytokine responses (detection of expression of interleukins 4, 13, 12 and interferon-γ by real-time polymerase chain reaction assays). RESULTS: Respiratory Syncytial Virus elicited lower levels of interleukin 4, when compared with samples without virus identification. A similar tendency to Th1 polarisation was found in older children, in those who attended day-care centres, and in breastfed individuals. Exposure to tobacco smoke was associated with a Th2 bias in this population. CONCLUSIONS: These findings show that Respiratory Syncytial Virus infection contributes to Th1 polarisation in immune response of respiratory mucosa, an effect that is similar to other environmental factors. Further studies are needed to assess immune response to other infectious causes of acute bronchiolitis.

Upper arm anthropometry is not a valid predictor of regional body composition in preterm infants.

BACKGROUND: Upper arm anthropometry has been used in the nutritional assessment of small infants, but it has not yet been validated as a predictor of regional body composition in this population. OBJECTIVE: Validation of measured and derived upper arm anthropometry as a predictor of arm fat and fat-free compartments in preterm infants. METHODS: Upper arm anthropometry, including the upper arm cross-sectional areas, was compared individually or in combination with other anthropometric measurements, with the cross-sectional arm areas measured by magnetic resonance imaging, in a cohort of consecutive preterm appropriate-for-gestational-age neonates, just before discharge. RESULTS: Thirty infants born with (mean +/- SD) a gestational age of 30.7 +/- 1.9 weeks and birth weight of 1,380 +/- 325 g, were assessed at 35.4 +/- 1.1 weeks of corrected gestational age, weighing 1,785 +/- 93 g. None of the anthropometric measurements are reliable predictors (r(2) < 0.56) of the measurements obtained by magnetic resonance imaging, individually or in combination with other anthropometric measurements. CONCLUSION: Both measured anthropometry and derived upper arm anthropometry are inaccurate predictors of regional body composition in preterm appropriate-for-gestational-age infants.

A simple equation to estimate the osmolarity of neonatal parenteral nutrition solutions.

UNLABELLED: A predictive equation of osmolarity that correlates closely with the measured osmolality was determined. Taking into account that an osmometer is not available in most clinical settings, the proposed equation appears to provide a quick and simple osmolarity calculation of neonatal parenteral nutrition solutions. OBJECTIVE: We measured the osmolalities of neonatal parenteral nutrition (PN) solutions to determine if these values may be predicted by a simple equation for calculation of their osmolarity values. METHODS: The osmolalities of 101 consecutive different final PN admixtures, prepared for 36 neonates, were measured by the freezing point depression method. The respective intra-assay and interassay coefficients of variation were always <2.1%. Linear multivariate regression analysis was used to determine a predictive equation of osmolarity that correlates closely with the value of measured osmolality. RESULTS: The mean (SD) osmolality of the final PN admixtures was 749.7 (165.4) mOsm/kg. The best-fitted equation, with a coefficient of discrimination R2 = .95 (R2 = .90 for samples between 500 and 1000 mOsm/L) is osmolarity (mOsm/L) = (nitrogen x 0.8) + (glucose x 1.235) + (sodium x 2.25) + (phosphorus x 5.43)-50, with the concentration of components in mmol/L. Adapting the equation in our daily practice, using g/L for glucose and amino acids, mg/L for phosphorus, and mEq/L for sodium, the equation is osmolarity (mOsm/L) = (amino acid x 8) + (glucose x 7) + (sodium x 2) + (phosphorus x 0.2) - 50, with a similar R2. CONCLUSIONS: Taking into account that an osmometer is not available in most clinical settings, the proposed equation appears to provide a quick and simple osmolarity calculation of neonatal PN solutions, thus allowing more accurate decisions to be taken regarding the choice of route and rate of administration of PN solutions.

Osmolality of solutions, emulsions and drugs that may have a high osmolality: aspects of their use in neonatal care.

OBJECTIVE: Administration of some hypertonic substances to neonates has been associated with a variety of adverse effects. This study was conducted to determine the osmolality of intravenous drugs and solutions used in neonates receiving intensive care. METHODS: Osmolality was measured by freezing point depression. Vasoactive drugs, diuretics, anticonvulsants, antimicrobials, and glucose and electrolyte solutions were some of the substances analyzed. RESULTS: The osmolalities of 90 substances were measured; the respective intra-assay and interassay coefficients of variation were always less than 5%. A few drugs were found to be extremely hypertonic (> 8000 mOsm/kg), and most of them contain propylene glycol as vehicle (e.g. digoxin, phenytoin, diazepam and phenobarbital). Other drugs, at the same concentration, evidenced a significant discrepancy of osmolality depending on the trademark. CONCLUSIONS: The finding of some extremely hypertonic drugs highlights the need for further investigation in order to study their potential adverse effects in neonates, as well as to evaluate any advantage in diluting, infusing slowly or even avoiding such substances. Given the fact that there exists a discrepancy in osmolalities in some drugs at the same concentration depending on the trademark, the more isotonic solutions should be the preferred choice for intravenous administration.

Upper arm measurements of healthy neonates comparing ultrasonography and anthropometric methods.

OBJECTIVE: To compare measurements of the upper arm cross-sectional areas (total arm area, arm muscle area, and arm fat area of healthy neonates) as calculated using anthropometry with the values obtained by ultrasonography. MATERIALS AND METHODS: This study was performed on 60 consecutively born healthy neonates: gestational age (mean+/-SD) 39.6+/-1.2 weeks, birth weight 3287.1+/-307.7 g, 27 males (45%) and 33 females (55%). Mid-arm circumference and tricipital skinfold thickness measurements were taken on the left upper mid-arm according to the conventional anthropometric method to calculate total arm area, arm muscle area and arm fat area. The ultrasound evaluation was performed at the same arm location using a Toshiba sonolayer SSA-250A, which allows the calculation of the total arm area, arm muscle area and arm fat area by the number of pixels enclosed in the plotted areas. STATISTICAL ANALYSIS: whenever appropriate, parametric and non-parametric tests were used in order to compare measurements of paired samples and of groups of samples. RESULTS: No significant differences between males and females were found in any evaluated measurements, estimated either by anthropometry or by ultrasound. Also the median of total arm area did not differ significantly with either method (P = 0.337). Although there is evidence of concordance of the total arm area measurements (r = 0.68, 95% CI: 0.55-0.77) the two methods of measurement differed for arm muscle area and arm fat area. The estimated median of measurements by ultrasound for arm muscle area were significantly lower than those estimated by the anthropometric method, which differed by as much as 111% (P < 0.001). The estimated median ultrasound measurement of the arm fat was higher than the anthropometric arm fat area by as much as 31% (P < 0.001). CONCLUSION: Compared with ultrasound measurements using skinfold measurements and mid-arm circumference without further correction may lead to overestimation of the cross-sectional area of muscle and underestimation of the cross-sectional fat area. The correlation between the two methods could be interpreted as an indication for further search of correction factors in the equations.

[Acute myocardial infarct in infants]. / Enfarte agudo do miocárdio na criança.

A retrospective study was made of 6 children, with nonsurgical-related acute myocardial infarction (AMI), between January 1987 and December 1994. The ratio for gender was 1 and mean age at AMI was 49 days, 4 cases being associated with congenital heart disease (Fallot's tetralogy, truncus arteriosus and DiGeorge syndrome, one case each, and anomalous origin of left coronary artery, 2 cases). Kawasaki disease and coronary embolisation from thrombosis of the renal vein occurred in the other 2 cases respectively. All developed congestive cardiac failure and cardiomegaly. In the ECG pathologic q waves with more than 35 msec occurred in all, and QT prolongation occurred in 3. Five children (83%) all with AMI in the anterior and lateral wall of the left ventricle died, death being related with cardiac mechanical failure and not with arrhythmias.