Current Pediatric Reviews - Volume 7, Issue 1, 2011

Upper airway (UAW) is defined as the extra-thoracic portion of the airway extending from the nose to the intra-thoracic inlet. It is divided into distinct segments such as the nose, pharynx, larynx and trachea. UAW has an exoskeleton of bones and cartilages on which more than 20 pairs of muscles are attached either directly or indirectly. UAW participates in a number of complex motor acts involving both the respiratory and alimentary systems. Although we take airway patency for granted, its significance is highlighted during cardio-pulmonary resuscitation. A patent upper airway is vital for survival. Peter Safar, a CPR pioneer, made the seminal observation which is the basis of UAW maintenance. He recognized the development of oropharyngeal obstruction during general anesthesia [1]. In an elegant study Wilson et al. determined the passive characteristics of the UAW and suggested that the UAW patency is actively maintained in the neonate [2]. Loss of UAW muscle tone with the onset of sleep predisposes the airway to obstruction, especially in obese adults. Research interest in sleep apnea served as further impetus to our understanding of UAW maintenance. Intrapleural negative pressure generated during inspiration acts as an airway collapsing force to the UAW. Nasal resistance, which accounts for nearly one-half the pulmonary resistance, increases markedly in the neonate when a nasogastric tube is inserted. As airway resistance increases, UAW is subjected to even greater airway collapsing force. Although airway obstruction occurs typically during sleep and anesthesia, UAW patency can also be compromised by other factors such as neck flexion or maldevelopment. Congenital airway disorders such as laryngomalacia, choanal atresia and Pierre Robin sequence constitute the major UAW disorders in the newborn. Airway resistance is increased in these disorders, often impairing gas exchange in severe cases and sometimes even threatening survival. Prompt investigations, diagnosis and intervention are required for optimal outcome. Endoscopic evaluation and non invasive imaging such as computerized tomography are very useful tools in this process. In a series of reviews we discuss key issues in these UAW disorders. The passive characteristics of the UAW, neural and chemical regulation of UAW muscles, and effect of sleep and arousal on muscle activity as well as basic pathophysiology of upper airway obstruction are discussed in the first article [3]. Some UAW muscles such as the alae nasi, posterior cricoarytenoid (PCA) influence UAW lumen markedly because of their strategic location. Respiratory activity of these muscles is altered by chemical and mechanical factors. For example, laryngeal mechanoreceptors responding to negative pressure changes promote UAW patency by increasing PCA and genioglosssal activity [4]. Bilateral choanal atresia which occurs as an isolated abnormality or as part of a syndrome (e.g., CHARGE syndrome) manifests clinically with airway obstruction, stridor, and cyanosis in the immediate neonatal period. In the vast majority of patients it is a mixed (bony/membranous) lesion. A temporizing measure such as an oral airway or intubation is often required prior to definitive surgical treatment. Surgical strategies include transnasal puncture, transpalatal resection and endoscopic resection. Typical post-operative management of choanal atresia includes a stenting period. Ramsden reviews in detail the diagnosis, etiology and surgical treatment of choanal atresia [5]. Pierre Robin Sequence is a collection of symptoms and signs including micrognathia, glossoptosis, intermittent upper airway obstruction and typically cleft palate. A majority of the patients responds to prone positioning and careful oral feeding. If airway obstruction persists or growth is inadequate, surgical intervention is indicated: glossopexy, mandibular osteogenesis or tracheostomy. Yu et al. address these critical issues in their review on Pierre Robin Sequence [6]. Stridor in the neonate has multiple causes. A basic physiological approach is needed to establish a diagnosis. This includes a detailed assessment of the characteristics of stridor, its associated features and the levels of respiratory distress. The differential diagnosis includes laryngomalacia, tracheobronchomalacia, subglottic stenosis, cysts, clefts, webs, hemangiomas and masses. Diagnostic laryngoscopy and bronchoscopy are required for most cases. Management ranges from observation and parental education in mild cases to relief of obstruction through surgical means. Masters addresses these and other important issues in his review [7]. Laryngomalacia is the most common cause of stridor in the neonates. It follows a benign, self-limiting course in the vast majority of cases. Surgical intervention is warranted only in a minority of patients. The surgical techniques have evolved over the years to endoscopic supraglottoplasty; tracheotomy can be avoided in most infants. Clinical symptoms, evaluation and surgical approaches are discussed in detail by Bedwell and Zalzal [8]. Endotracheal intubation and mechanical ventilation often help to stabilize the infants with severe upper airway problems. However, subglottic stenosis in the neonate is often acquired and is caused by prolonged mechanical ventilation. The incidence of acquired subglottic stenosis has decreased significantly in recent years. Prior to the introduction of airway reconstruction, tracheotomy was the primary treatment option. Endoscopic airway techniques have expanded the surgical options with laryngotracheal reconstruction as the mainstay for moderate and cricotracheal resection for severe stenosis. Meier and White discuss the management of subglottic stenosis with an emphasis on current surgical techniques [9].....

Extrathoracic portion of the airway can be defined as the upper airway (UAW) which serves both alimentary and respiratory functions. It accounts for a significant portion of the dead space and total airway resistance. Activation of UAW muscles must be precisely coordinated to achieve the desired results in several complex motor acts such as respiration, airway protection, phonation, mastication and swallowing. A patent UAW is vital for survival. This review critically evaluates key factors that influence UAW patency with special emphasis on the neonate.

Congenital narrowing of the nasal airway at the posterior choanae is an uncommon condition in pediatric patients, which can be uni- or bilateral. The presentation of bilateral choanal atresia is a neonatal airway emergency, requiring prompt treatment. The repair of unilateral choanal atresia is often an elective surgical procedure of early childhood, for which a variety of techniques have been described. Choanal atresia occurs as an isolated abnormality, or as part of a syndrome, most commonly CHARGE syndrome. Choanal atresia, and associated abnormalities such as abnormal semicircular canals and cranial nerve abnormalities, are integral part of the diagnosis of CHARGE syndrome. There is increasing understanding of the biology of choanal atresia, and aetiological risk factors are starting to become apparent. This review will discuss the diagnosis, aetiology, and surgical treatment of choanal atresia.

This is a mini-review of the etiopathogenesis and management of Pierre Robin Sequence (PRS). PRS is the combination of intermittent upper airway obstruction, glossoptosis, microgenia, and retrognathia, with or without cleft palate. 70 to 75% of PRS babies can be managed by prone positioning. Failing conservative measures, classified as Caouette-Laberge Group III PRS patients, surgical airway management is necessary and includes tongue-lip adhesion, mandibular distraction, or tracheostomy. The objectives are to provide a comprehensive, practical, and updated synopsis for health care professionals involved in the care of this group of patients, so that accurate diagnosis can be made, logical treatment plan can be formulated, and effective therapy can be carried out. Particular emphasis is placed on the management for Group III patients with focus on the technical aspects of the tongue-lip adhesion and distraction osteogenesis in this review.

Stridor in the neonate is a sign that necessitates a basic physiological approach to establish a diagnosis. This includes a detailed assessment of the characteristics of the stridor; its associated features particularly voice quality, swallow, cough as well as general features and finally the levels of respiratory distress. The differential diagnosis is wide ranging, the associated features are common and the associated distress is highly variable. Common disorders causing stridor in the neonate include laryngomalacia, tracheobronchomalacia disorders, subglottic stenosis, and cysts; while vocal cord immobility, clefts, webs, hemangiomas and masses are rare. Diagnostic laryngoscopy and bronchoscopy are required in many cases. Management ranges from observation and parental education in mild cases to relief of hypoxia, relief or removal of obstruction and treatment of the specific causes through surgical means in the severe and potentially dangerous. A specialized chronic illness teamwork approach including medical, paramedical, psychological support for the child and family and otolaryngological and surgical teams is often required to ensure a satisfactory outcome.

Laryngomalacia is the most common cause of stridor in neonates. It generally presents as occasional inspiratory stridor, but may be associated with feeding problems, failure to thrive, and significant respiratory distress. The majority of patients are managed conservatively with watchful waiting and anti-reflux medication, and can expect to see symptom resolution by 12-18 months of age. About 10% of patients require surgical treatment for their symptoms. Surgical management has evolved over the past century from tracheotomy to the modern endoscopic supraglottoplasty. Results of this surgery are excellent, and severe complications, such as supraglottic stenosis and aspiration, are uncommon.

The surgical options for children with subglottic stenosis (SGS) have evolved from primarily tracheotomy fifty years ago to open and endoscopic techniques today. Improved airway management in the neonatal intensive care unit and better understanding of gastroesophageal reflux and its impact in the neonatal airway have decreased the overall incidence of subglottic stenosis. However, SGS remains a significant cause of morbidity in the neonatal population. Laryngotracheal reconstruction with cartilage grafting is the most common treatment for moderate subglottic stenosis. Cricotracheal resection is a more extensive operation but has achieved excellent results in children with severe subglottic stenosis. Developing endoscopic airway techniques using instruments such as balloon dilators, carbon dioxide lasers, and microdebriders, continue to expand the surgeon's armamentarium in treating subglottic stenosis. This paper reviews the evaluation and management of subglottic stenosis with an emphasis on discussing current surgical techniques.

Tuberculin Skin Tests (TST) are widely used but its utility is compromised by variations in reading the reactions by different observers, as studies over time have consistently shown that health care providers do not always follow established recommendations. To help ensure consistency among TST readers, Centers for Disease Control and Prevention (CDC), Atlanta, USA recommends that the induration following administration of a TST must be measured transverse to long axis of the forearm. Existing literature on measurement of delayed skin test responses have all examined the advantage of using the pen versus the palpation technique for measuring induration, and to the best of our knowledge, none have factored in the role of superficial lymphatics that possibly can influence the vertical diameter of the induration following a TST. Accurate measurement of a TST forms an important element in the continuum of standard of care between administration of a TST and its correct interpretation, and errors in interpretation can lead to institution of inappropriate therapy. It is hoped that this mini-review provides a logical insight based on best available evidence into the possible role of superficial lymphatics in influencing the vertical diameter of the induration along the long axis of the forearm thereby also reinforcing CDC's recommendation for measuring the induration of a positive TST transverse to the long axis of the forearm.

Suicide is one of the most common causes of death among young people worldwide. Adolescence is a developmentally important phase of age due to the growing risk for suicide and prevalence of psychiatric disorders, as well as due to growing possibilities for prevention and treatments. Research findings in theoretical considerations, in psychological autopsy studies as well as in selected follow-up studies of clinical populations and suicide attempters analyzing risk factors for youth suicides are reviewed emphasizing the most recent data. As youth suicides are rare, research on risk factors for youth suicidal ideation, deliberate self-harm behavior and attempted suicide are also briefly reviewed. Family-related adversity, precipitating interpersonal problems, and particularly psychiatric disorders constitute risk factors for adolescent suicide. Mood disorders, substance abuse and prior suicide attempts are strongly related with youth suicides. However, recent psychological autopsy studies in China have found substantially lower rates of psychiatric disorders among suicide victims compared with those in the Western countries. Recognition and effective treatment of psychiatric disorders, e.g. depression are essential in preventing adolescent suicides. As only seldom young suicide victims have received psychiatric care, broad prevention strategies are needed in health care and social services. Education of physicians to recognize youth at risk, and restricting access to lethal means are recommended to prevent suicides. For high-risk youth providing continuity of care is important. Recent treatment studies among suicidal adolescents have reported promising results on safety planning and increased therapeutic contact early in treatment.

Background: Sickle cell disease is a hemoglobinopathy of global importance due to its worldwide high prevalence. Endocrine and metabolic disorders may be associated with this disease, aggravating its clinical course. Objective: Evaluate the current knowledge about metabolic and endocrine derangements related to sickle cell anemia. Source: Literature search was performed in MEDLINE and SciELO databases, in the last 20 years, combining in different compositions the following terms: sickle cell disease, short stature, delayed puberty, diabetes mellitus, osteoporosis, hypothyroidism and adrenal dysfunction. Results: Endocrine disorders in sickle cell disease have multifarious causes: tissue hypoxia, chronic anemia, iron overload, high energy demand, genetic influence and malnourishment. Slow speed of growth and delayed puberty are frequent. The most common endocrine disorders in sickle cell disease are: growth delay, osteopenia and hypogonadism. Diabetes mellitus, thyroid and adrenal disorders are overall rare in this population. Conclusion: Recognition of an endocrine disturbance is of utmost importance in the follow-up of sickle cell disease patients. Thus, preventive measures, early diagnosis and replacement of specific hormonal deficiencies may be implemented contributing to a better quality of life for these patients.