1,720,973 research outputs found
Pharmacology of Drugs used in Children
No full textThe pharmacokinetics (PK) and pharmacodynamics
(PD) of most medications in children, especially neonates, differ
from those in adults. Children have immature renal and hepatic
functions, different body composition, altered protein binding,
distinct disease spectrum, diverse behavior, and dissimilar receptor
patterns. PK differences necessitate that the dose is modified to
achieve the desired concentration to elicit an appropriate pharmacodynamic response and to avoid toxicity. Some medications may
displace bilirubin from its protein binding sites, predisposing to
kernicterus in premature neonates. Drug effect may be influenced
by the reduced capacity of end organs such as the heart, neuromuscular junction, and brain to respond to medications in children compared with adults. In this chapter we discuss basic
pharmacologic principles as they relate to drugs commonly used
in infants and children
Do Anesthetic Drugs Harm Neonates? A Global Perspective
No full textThere is still much to be discovered regarding the effects of anesthetics on the developing and immature human brain and the mechanisms behind this effect. Given that N-methyl-D-aspartate (NMDA) and gamma-aminobutyric acid A (GABAA) receptors modulate brain development and growth, it is biologically plausible that if anesthetics, which exert their actions via these same receptors, are administered during the period of rapid brain development, they may adversely affect long-term neurocognitive development. Numerous studies in neonatal animals have demonstrated both short- and long-term neurological deficits. However, evidence from animals does not necessarily portend similar outcomes in humans. Moreover, neurocognitive outcome studies in humans have yielded conflicting evidence. Despite these results, repeated controversial and alarming statements that children who receive general anesthesia may sustain adverse neurological outcomes have been issued repeatedly by federal agencies based primarily on preclinical animal studies and weak human evidence. In the absence of alternatives to the current general anesthetics and the possible risks associated with delaying most surgeries, choosing which anesthetics are least likely to cause long-term neurocognitive outcomes in humans is a daunting challenge. Knowing that the underlying disease processes, surgical interventions, and trauma, as well as other perioperative factors, significantly impact the neurocognitive outcome, isolating the effects of anesthetics on these outcomes becomes even more challenging. Whether we can ever determine the effects of anesthetics themselves on neurocognitive outcomes in human infants and children remains before us.</p
Revisiting a Common Measure of Child Postoperative Recovery: Development of the Post Hospitalization Behavior Questionnaire for Ambulatory Surgery (PHBQ-AS)
Full text linkBackground
The Post Hospitalization Behavior Questionnaire (PHBQ) was designed for assessing children\u27s posthospitalization and postoperative new‐onset behavioral changes. However, the psychometric properties of the scale have not been re‐evaluated in the past five decades despite substantial changes in the practice of surgery and anesthesia. In this investigation, we examined the psychometric properties of the PHBQ to potentially increase the efficacy and relevance of the instrument in current perioperative settings. Method
This study used principal components analysis, a panel of experts, Cronbach\u27s alpha, and correlations to examine the current subscale structure of the PHBQ and eliminate items to create the Post Hospitalization Behavior Questionnaire for Ambulatory Surgery (PHBQ‐AS). Data from previous investigations (N = 1064, Mage = 5.88) which utilized the PHBQ were combined for the purposes of this paper. Results
A principal components analysis revealed that the original subscale structure of the PHBQ could not be replicated. Subsequently, a battery reduction, which utilized principal components analysis and a panel of experts, was used to eliminate the subscale structure of the scale and reduce the number of items from 27 to 11, creating the PHBQ‐AS. The PHBQ‐AS demonstrated good internal consistency reliability and concurrent validity with another measure of children\u27s psychosocial and physical functioning. Conclusion
Revising the former subscale structure and reducing the number of items in the PHBQ to create the PHBQ‐AS may provide a means for reducing the burden of postoperative behavioral assessment through decreasing time of administration and eliminating redundancy of items and allow for more accurate measurement of child postoperative behavioral changes
Total intravenous anesthesia and target-controlled infusion
No full textTotal intravenous anesthesia (TIVA) is the use of intravenous agents for induction and maintenance of anesthesia. The
most frequently used agent is propofol. Propofol effect is usually
augmented with an opioid (e.g., remifentanil). Although it is possible to implement TIVA using pumps with the infusion rate
controlled manually, the advent of pumps programmed with
pharmacokinetic information has facilitated use. The use of published pharmacokinetic parameter sets (referred to as models and
often described by the principal author) allows the pump to determine infusion rates to maintain a certain plasma concentration
(Cp) and the addition of an effect-site equilibration constant
(keo) allows effect-site drug concentration prediction. Covariate
knowledge (e.g., weight, age) allows individualization of dose.
Recommended target concentrations for both propofol and remifentanil depend on the type of surgery, the degree of surgical
stimulation, the use of local anesthetic blocks and the ventilation
status of the patient. The use of processed EEG monitoring is
helpful in pediatric TIVA anesthesia, particularly in the presence
of neuromuscular blockade
Orthopedic and Spine Surgery
No full textAnesthesia for orthopedic and spine surgery provides a
multitude of challenges. Children often present with concomitant diseases that affect cardiovascular and respiratory function.
Operating times can be protracted, particularly for scoliosis surgery. Many of these procedures involve children already severely
compromised by muscle weakness and impaired respiratory function. Improvement in monitoring of spinal cord function helps to
minimize neurological risk. Considerable blood loss can occur
that requires strategies for blood product management and transfusion reduction. Major trauma causing orthopedic injuries invariably involves other organ systems that may adversely interact
with or compromise anesthesia management. The risks of pulmonary aspiration of gastric contents and the requisite fasting times,
after even minor trauma involving an isolated forearm fracture,
continue to be debated. Fat embolus is uncommon in children
with long-bone fractures but should be considered in any child with hypoxia and altered consciousness in the perioperative
period. Tumor surgery may be complicated by chemotherapy,
altered drug disposition, or bone grafting considerations akin
to those for plastic and reconstructive surgery, and complex postoperative pain management may be required. Positioning children on the operating table involves care, especially for those with
limb deformities and contractures. Patients with a variety of
syndromes also require other orthopedic procedures to assist in
minimizing the impact of those syndromes on their quality of
life. These syndromes present their own unique anesthetic challenges. The anesthesiologist plays a major role for facilitating
surgery and providing optimal postoperative care, and particularly pain management.
Chapter number:
3
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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