Current Pediatric Reviews - Volume 2, Issue 4, 2006

The transition to extra-uterine life at birth represents a remarkable physiological challenge, particularly in pulmonary physiology as the lungs must immediately take over the role of gas exchange at birth. The extent of the change in pulmonary physiology that must occur at birth in order for the lungs to transform into an efficient gas exchange organ is exemplified by change in the pulmonary circulation. Throughout gestation, pulmonary vascular resistance (PVR) is high and the majority of right ventricular output bypasses the lungs and passes through the ductus arteriosus into the systemic circulation. As a result, fetal pulmonary blood flow (PBF) is low, but rapidly increases at birth due to a very large reduction in PVR, which also results in a gradual reduction in pulmonary arterial pressure. Despite the physiological significance of maintaining a high PVR during fetal development and of the large and rapid reduction in PVR at birth, the precise mechanisms controlling perinatal pulmonary haemodynamics are not fully understood. In particular, the role of intra-luminal pressure in regulating pulmonary haemodynamics in the immature lung before and after birth has received relatively little attention, although it is known to have a major impact in the adult lung. In this review, our primary aims are to discuss the importance of intra-luminal pressure in the maintenance and control of pulmonary haemodynamics both in utero, and postnatally, in preterm sheep. This review examines both chronic and phasic alterations in intra-luminal pressure, and the subsequent influence on pulmonary haemodynamics. Although very little data is available on preterm human fetus and infants, it is highly likely that the concepts discussed in this review are directly applicable to humans.

With the epidemiology now well described, stroke has been uncovered as a frequent cause of neurological disease in children. Arterial ischemic stroke (AIS) is the most common type, affecting both neonates and older children. The number of associated risk factors is large with current efforts directed toward understanding the mechanisms by which they translate into a stroke. Advanced neuroimaging modalities are improving diagnostic accuracy while affording unique avenues to explore the pathophysiology of stroke and the response of the developing brain to injury. While acute interventions for pediatric stroke are in their infancy, the first randomized controlled clinical trials for the initial management and secondary prevention of pediatric stroke are poised to begin. Outcomes from childhood stroke are well defined though the accurate predictors required to guide treatment and rehabilitation remain elusive. We review the essential background, recent advances, and current clinical research issues pertaining to AIS in children.

Neonatal seizures (NS) are generally an acute manifestation of disturbance of the developing brain and are very common in the first weeks of life. Many studies have been published concerning risk factors, etiology, identification, treatment and outcome of newborns with seizures, however, an important question as why the outcome is so diverse among neonates with seizures is still open to discussion. A literature review was performed with the help of the Medline database by crossing the key words neonatal seizures and outcome. From 1973 to 2005, 851 references were found and after screening title and abstract, 36 were selected, which could be identified as prospective studies that analyzed the risk factors and outcome of NS. The main risk factors for NS were prematurity, low birth weight, antenatal complications, meconium staining and need of subsequent respiratory support. The most frequent etiology reported in all studies was hypoxic ischemic encephalopathy. Mortality ranged from 12 to 61%. Clinical predictors of outcome were seizure type, onset, etiology and duration besides abnormal neonatal examination. The background rhythm of neonatal EEG was also a very good predictor of outcome. The incidence of epilepsy after neonatal seizures varied from 9.4 to 56%, most of the newborns that developed postneonatal epilepsy had epileptic syndromes with unfavorable prognosis. In conclusion, neonatal seizures seem to be associated with elevated morbidity and mortality directly related to the gravity of the encephalic injury.

Congenital Disorders of Glycosylation (CDG) are a rapidly growing family of genetic and mostly multisystem diseases caused by defects in the biosynthesis of the glycan moiety of glycoconjugates such as glycoproteins. Since the description of the first patients by Jaeken et al. in 1980, 23 defects have been identified in N- and O-protein glycosylation: 18 defects in N- or N- and O-glycosylation (12 glycan assembly defects: CDG-Ia to CDG-IL; 6 glycan processing defects: CDG-IIa to CDG-IIf) and 5 defects in O-glycosylation. There is a rapidly growing number of patients with a putative CDG in whom the known defects have been excluded (CDG-x). This review focuses on recent developments in the field including advances in the biochemical and molecular diagnosis of CDG and new features of known CDG. It also deals with the identification of new protein glycosylation disorders, of the first lipid glycosylation disorder, and of the emerging group of hyperglycosylation disorders. Finally, we speculate about future developments.

For many years the gold standard in diagnosing pneumonia has been the chest x-ray, both in clinical practice and for research purposes. The objective of this review was to examine the evidence to determine the role of chest x-ray in the diagnosis of pneumonia. A comprehensive literature search was conducted and abstracts were obtained from articles that, judged by their titles, bore relevance to the subject in question. Articles were selected for review based on their abstracts. Articles were subsequently reviewed, appraised and results were presented by grading evidence as Level I, II or III. Even the best available evidence failed to demonstrate improved outcome with the addition of chest radiography in ambulatory acute lower-respiratory infection in children. There is little evidence to justify the routine use of chest radiography in the diagnosis of pneumonia in children, but more research is needed to explore the potential benefit of chest radiography in specific clinical scenarios.

Deep inhalation (DI) induces changes in airway calibre that may last beyond the manoeuvre itself. The mechanisms involve mechanical interaction between conducting airways subjected to parenchymal tethering and lung parenchyma itself. Healthy children usually show small bronchodilation after DI. Increased airway calibre after DI has been documented in wheezy preschool children with mild airway obstruction and, after methacholine challenge, in preschool and school children with normal lung function but has not yet been demonstrated in infants. The DI also induces bronchodilation in children with mild exercise induced airway obstruction. In the presence of severe airway obstruction, the bronchodilatory effect of DI may be blunted or reversed. The bronchodilatory effect of DI appears to be larger in children and adults than infants and elderly and larger in girls than boys. It is inversely related to the degree of airway hyperresponsiveness and the blunted bronchodilatory response to DI in acute or severe asthma is restored by steroid therapy or allergen avoidance. The airway effects of DI may in the future prove a valuable tool in assessing the mechanisms of airway obstruction and reactivity in children.

The diagnosis of appendicitis in infancy is very difficult to make and is thus usually delayed. This delay is often associated with complications such as perforation and abscess formation as well as prolonged hospital stays and increased litigation. Despite the advent of newer diagnostic tools, such as ultrasonography and CT scan, as well as the volumes of knowledge that have surfaced regarding appendicitis in the younger age group, the diagnostic accuracy has not improved. Experts agree that many clinicians do not have a high enough index of suspicion for appendicitis in the younger child. This case presentation and review of the literature is intended to emphasize to the general practitioner that while appendicitis occurs rarely in infants and toddlers, it should continue to be considered as part of the differential diagnosis in the evaluation of an infant/toddler with vomiting, diarrhea, or a simple “tummy ache”.

Biliary atresia (BA) is a rare congenital condition which results in significant morbidity and mortality. The Kasai hepatic portoenterostomy and liver transplantation have significantly improved survival in this disease; however, unraveling the etiology/etiologies will be required to improve transplantation free survival. At present, BA is still the single most common condition in children on pediatric liver transplant waiting lists and accounts for up to 50% of those waiting for liver transplantation [1]. It is the most rapidly fibrosing liver disease in man and accounts for ∼10% of all liver transplant procedures performed [2]. The rarity of this condition and the likelihood of a multi-factorial etiology have limited progress in research. Recently, collaborative research networks in North America (BARC) and Europe (EBAR) have been established [3,4]. The following discussion outlines the most recent information available from these and other groups concerning epidemiology, pathophysiology, etiology, diagnosis, management, long term outcome and conclusions/ recommendations for future research.

For many families of pediatric cancer patients the use of complementary/alternative medicine (CAM) is an accepted adjunct to conventional therapy, even if data regarding effects and risks are scarce. This report provides information about the prevalence of CAM use and reasons for CAM use among pediatric cancer patients. We report the studies available in the literature concerning pediatric oncology and summarise what is known about beneficial effects and risks that could be attributed to certain complementary and alternative methods. Frequently used CAM like mind-body medicine, nutrition (incl. diets and vitamins), homeopathy, anthroposophic medicine, phytotherapy, and acupuncture are highlighted, as were CAM with a lesser percentage of users, bearing special risks (e.g. interactions with chemotherapy) and/or are costly for their users. Physicians should be aware that a substantial percentage of their patients may use CAM without telling them. Physicians need to be open-minded and should discuss CAM with parents, because parents often think that CAM is natural and, therefore, safe. On the other hand, physicians often lack basic knowledge concerning CAM leading to an avoidance of talking about CAM with parents. A professional differentiation between potentially useful and potentially dangerous CAM is necessary to aim at minimising the risks for CAM users.

Emerging empirical evidence indicates that parenting strategies can have a substantial impact on their adolescents' sexual health. Three critical parenting strategies: monitoring their adolescents, engaging them in frequent communication about sex, and, providing familial support may afford protection against their adolescents engaging in sexual risk behaviors, and consequently, reducing adolescents' risk of adverse sexual health outcomes such as unintended pregnancy and sexually transmitted diseases including human immunodeficiency virus infection. Family-based interventions can successfully enhance the adoption of all of these protective strategies; however, pediatricians routinely come into contact with parents and their adolescents. Pediatricians can therefore serve as an authoritative source of information and motivation by encouraging parents to monitor their children more closely, enhance parent-adolescent communication about sexual health and encourage a more supportive family environment to enhance the likelihood that adolescents will adopt and maintain sexual health promotion practices. In addition, pediatricians can provide parents with an information prescription (IP) to assist them in acquiring information via the Internet on adolescent sexual health and risks, and on the three critical parenting protective strategies. Thus, pediatricians represent an important and, perhaps, cost-effective intervention point with parents who in turn can protect the sexual health of their adolescents.