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Current Pediatric Reviews
ISSN: 1573-3963
Current Pediatric Reviews
Volume 2, Number 3, August 2006
Contents
Ventilation of Very Preterm Infants in the Delivery
Room Pp. 187-197
Arjan B. te Pas and Frans J. Walther
[Abstract]
Neonatal Environment and Neuroendocrine Programming
of the Peripheral Respiratory Control System Pp.
199-208
Aida Bairam, Richard Kinkead and Vincent Joseph
[Abstract]
Pathophysiology of Arterial Hypertension: Insights
from Pediatric Studies Pp. 209-223
Ana Cristina Simões e Silva
[Abstract]
How to Measure Renal Function in Children –
What is the Role of Cystatin C? Pp. 225-231
Guido Filler
[Abstract]
Nutritional Assessment in the Critically Ill Child
Pp. 233-243
George Briassoulis
[Abstract]
Chest Pain in Children Pp. 245-258
Jason E. Lang and Andrew A. Colin
[Abstract]
Management of Parapneumonic Effusions: Current Practice
and Controversies Pp. 259-263
Michael Weinstein
[Abstract]
Back Pain in Children and Adolescents: Etiology, Clinical
Approach and Treatment Pp. 265-286
Athanasios I. Tsirikos and Kosta Kalligeros
[Abstract]
Abstracts
[Back to top]
Ventilation of Very Preterm Infants in the Delivery
Room
Arjan B. te Pas and Frans J. Walther
Adequate functional residual capacity (FRC) is difficult to
create with manual ventilation in very preterm infants and
carries a high risk for creating lung damage. International
guidelines for neonatal resuscitation do not provide ventilation
guidelines for very preterm infants despite evidence that
a different approach may be warranted. Peak inspiratory pressures
(PIPs) generated with bag and mask ventilation are usually
insufficient to open up the lung or unintentionally excessive.
The long time constant of the fluid-filled immature lung can
be overcome by delivering a prolonged inflation at a lower
PIP, followed by application of positive end-expiratory pressure
(PEEP) to maintain FRC after lung recruitment. To minimize
the damage provoked by manual ventilation a consistent PIP,
adequate PEEP and prolonged inflation have to be guaranteed.
A mechanical pressure-limited T-piece resuscitator is the
only device that meets these requirements. Leakage between
mask and face is prevented by using the nasopharyngeal route.
After resuscitation, FRC can be preserved by starting nasal
continuous positive airway pressure (nCPAP) in the delivery
room, which will reduce the need for intubation and mechanical
ventilation. This review discusses the accumulated data supporting
these recommendations.
[Back to top]
Neonatal Environment and Neuroendocrine Programming
of the Peripheral Respiratory Control System
Aida Bairam, Richard Kinkead and Vincent Joseph
The carotid bodies are the main peripheral oxygen sensors
involved in cardio-respiratory control under normoxic and
hypoxic conditions. The present review briefly describes carotid
body function during “normal” development and
then presents recent results showing how environmental factors
affect the trajectory of these developmental processes. This
review then focuses on data obtained from our laboratories,
which emphasise the short-term modulation and long-term consequences
of perinatal stress such as premature deprivation of placental
steroids and neonatal disruption of mother-infant interactions
on carotid body development and function. Our current data
suggest that disturbances related to early deprivation of
placental steroids, as it occurs with premature delivery,
disrupt respiratory chemoreflexes attributed mainly to chemoreceptor
cells’ ability to respond to changes in oxygen levels
during early life. Conversely, stress related to interference
with normal mother-pup interactions during the neonatal period
induces changes in carotid body function that persist well
into adulthood. In both cases, changes in carotid body function
are related (at least in part) to significant modification
of dopaminergic neurotransmission within the carotid body
as suggested by treatment-related changes in dopamine D2
receptor gene expression level. Together, these data suggest
that these environmental factors predispose to the occurrence
of respiratory disease associated with respiratory control
dysfunction such as sleep-disordered breathing during infancy.
[Back to top]
Pathophysiology of Arterial Hypertension: Insights
from Pediatric Studies
Ana Cristina Simões e Silva
Blood pressure is the direct product of cardiac output and
total peripheral resistance. Cardiac output is regulated by
preload, myocardium contractility and heart rate, while total
peripheral resistance depends on afterload and vessel elasticity.
The maintenance of blood pressure within normal limits is
influenced by neural, humoral and local control mechanisms,
which have extensive and complex interactions, making difficult
an individual analysis. Thus, isolated or combined disarrangements
in these mechanisms can lead to the development of hypertension.
Neural blood pressure regulation mainly depends on lower brain
stem centers of cardiovascular control and the autonomous
nervous system, integrating the cardiovascular reflexes. In
regard to humoral mechanisms, several substances/ systems
contribute for increasing blood pressure (Angiotensin II,
circulating cathecolamines), while others can play a counterregulatory
role [Angiotensin-(1-7), kallikrein-kinin system and natriuretic
peptides]. Moreover, local factors, such as nitric oxide and
endothelins, act as determinants of vascular resistance and
as systemic or local modifiers of neural and humoral mechanisms.
Recently, research has begun to disclose the mechanisms related
to blood pressure regulation at cellular and molecular level.
In this review, we discussed experimental and clinical evidence
relating to regulatory mechanisms probably involved in the
pathophysiology of arterial hypertension with insights from
pediatric studies.
[Back to top]
How to Measure Renal Function in Children –
What is the Role of Cystatin C?
Guido Filler
Assessment of renal function is important. The gold-standard
marker is glomerular filtration rate (GFR) measured by inulin
clearance normalized to a standard body surface area of 1.73
m2. Inulin, no longer available in North America,
has been replaced by nuclear medicine tests such as 51Cr
EDTA, 99mTc DTPA and iothalamate clearances.
The use of serum creatinine as a surrogate endogenous marker
is hampered by height, gender and muscle mass variability,
substantial tubular secretion in advanced renal failure and
non-standardized measurements. The limitations of creatinine
can be reduced when applying height/creatinine ratios with
gender and age-dependent constants that have to be established
for each center.
The small molecular weight protein cystatin CysC shows a significantly
better diagnostic performance for the detection of impaired
GFR than serum creatinine. It also does not undergo tubular
secretion in chronic renal failure, nor does it show significant
non-renal elimination. Its concentration falls in the first
year of life with the rise of GFR and remains constant thereafter
until 60 years of age in both sexes. GFR can be estimated
reliably with a recently published formula without the need
for any additional anthropological data. CysC allows for reliable
estimation of GFR in children.
[Back to top]
Nutritional Assessment in the Critically Ill Child
George Briassoulis
Malnutrition is highly prevalent in critically ill children.
Several studies have recently reinforced the relationship
between poor nutritional status and higher incidences of complications,
mortality, length of hospital stay and costs. A variety of
methods used for assessment of different components of energy
expenditure has been validated and used in critically ill
children. Although reference values derived from representative
groups of healthy children and adolescents are now available,
hypercatabolism along with hypometabolism or hypermetabolism
is frequently seen in critically ill children. Methods for
assessment of the different components of energy expenditure
have been validated in critically ill children and adolescents.
There are, however, significant disadvantages of the available
tools and of the methodological aspects of assessment of energy
expenditure in a pediatric intensive care setting. The combined
use of these methods together with detailed analyses of body
composition is recommended for future studies. Although, the
evaluation of nutritional status is a broad topic that encompasses
several clinical variables, in patients with acute critically
illness measurements of energy expenditure are necessary.
[Back to top]
Chest Pain in Children
Jason E. Lang and Andrew A. Colin
Pain arising from the chest area creates anxiety in children
and their parents, often leading to unnecessary activity restriction,
school absences, and medical utilization. A thorough but pragmatic
evaluation requires a grasp of the pathophysiology of several
organ systems and an understanding of epidemiologic and behavioral
patterns specific to children. Few symptoms in pediatrics
test a clinician’s skill more than chest pain. Though
the etiology is frequently benign, it is often uncertain,
and sprinkled among cases of chest pain are potentially fatal
conditions.
This review summarizes chest pain in children of all ages,
with particular emphasis on adolescents. We review the organic
causes including musculoskeletal trauma, strain and inflammation,
respiratory conditions such as occult asthma, pneumonia and
bronchitis, and the important role of esophageal disease.
We discuss the relatively minor role of cardiac disease, but
highlight the conditions that are vital to consider, such
as arrhythmia, mitral valve disease, Kawasaki syndrome, Marfan
syndrome, and cocaine use. Anxiety, depression, and other
psychological factors often further complicate the presentation.
A pediatrician’s best tools are diagnostic acumen, which
may be lifesaving, and supportive dialogue, to impart reassurance
to a worried family.
We explore the most common and most lethal causes by age,
organ system, and predisposing illness. We review the neuroanatomic
considerations important in visceral, chest wall, and mediastinal
pain, and the sensation within the lung, airways, and pleurae.
Lastly, we highlight pragmatic ‘take-home’ tips
for the clinician, most of which involve good history-taking
and physical examination, but also include the utility of
basic testing that can detect the rare cases of fatal cardiopulmonary
disease.
[Back to top]
Management of Parapneumonic Effusions: Current Practice
and Controversies
Michael Weinstein
The incidence of complicated parapneumonic effusions in children
has been increasing over the past decade despite the increasing
use of protein-conjugate vaccines against Streptococcus
pneumoniae, the most common cause of complicated pneumonia
in children in the developed world. Despite the fact that
this condition is increasingly common in hospitalized children,
the management of this condition remains controversial, in
large part due to the small number of prospective, controlled
trials evaluating therapies. This review will highlight the
epidemiology, diagnosis and management of complicated parapneumonic
effusions. The role for intrapleural fibrinolytic therapy
and early video-assisted thorascopic surgery in the management
of this condition will be emphasized as will the questions
that need to be answered with future inquiry.
[Back to top]
Back Pain in Children and Adolescents: Etiology, Clinical
Approach and Treatment
Athanasios I. Tsirikos and Kosta Kalligeros
The purpose of this systematic review is to investigate back
pain as a clinical presentation in childhood and adolescence
providing the clinician with a comprehensive approach, which
will enable for an early recognition of those spinal disorders
in need of more aggressive medical intervention. The current
literature suggests that young people have a fairly high incidence
of non-specific back pain, which seems to be much more frequent
than traditionally reported. In schoolchildren, low back pain
is mainly associated with psychosocial factors and seems to
be mostly benign and self-limiting, therefore, only occasionally
requiring medical attention. However, young patients who seek
medical assistance, have a higher incidence of organic conditions
that can manifest with spinal pain as their predominant symptom.
The evaluation of a child or adolescent presenting with back
pain can be a challenging task and requires skilled clinical
expertise and a high index of suspicion. The physician should
have a carefully planned strategy for assessing the pediatric
spine patient, which should be accurate, reliable, consistent,
and easily reproducible in delineating spinal pathologies.
This should include a detailed history, physical examination,
radiographic imaging, and appropriate diagnostic laboratory
studies. A specific diagnosis will be established in at least
50% of the patients. In certain cases, an exact diagnosis
cannot be made, and it is always advisable to re-evaluate
the child after a period of initial observation. By then more
serious problems will advance and become more obvious while
minor symptoms not linked to an underlying pathology will
resolve spontaneously.
The authors did not receive grants or outside funding in support
of their research or preparation of this manuscript. They
did not receive payments or other benefits or a commitment
or agreement to provide such benefits from a commercial entity.
No commercial entity paid or directed, or agreed to pay or
direct, any benefits to any research fund, foundation, educational
institution, or other charitable or non-profit organization
with which the authors are affiliated or associated.
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