Use of helium-oxygen mixtures to relieve upper airway obstruction in a pediatric population

OBJECTIVES

Helium as a component of inspired gas decreases turbulent flow and airway resistance. Helium-oxygen mixtures have been used since the 1930s in the management of patients with upper airway obstruction. The objective of this study was to evaluate the efficacy of helium-oxygen mixtures in relieving upper airway obstruction in a pediatric population.

STUDY DESIGN

Retrospective chart review of 42 pediatric patients who received helium-oxygen mixtures for upper airway obstruction within a 3-year period.

METHODS

The study protocol included 42 pediatric patients, aged 1 week to 14 years, who were admitted to the Children's Hospital of Philadelphia from June 1997 to December 2000 and who received a total of 44 treatments of helium-oxygen therapy for upper airway obstruction. Response to treatment was determined by reduction in work of breathing noted on the chart.

RESULTS

Thirty-two of 44 helium-oxygen treatments resulted in a positive response (73%). There were no significant differences in demographic characteristics between responders and nonresponders, except all of the premature infants were responders and 6 of the 9 patients with syndromes were nonresponders.

CONCLUSIONS

Helium-oxygen therapy is a useful adjunct therapy for upper airway obstruction. Controlled clinical trials are necessary to better define the appropriate settings for use of helium-oxygen.

Transforming growth factor and neutralizing antibodies in subglottic stenosis

Transforming growth factor beta 1 (TGF-beta1), which is implicated in the pathogenesis of fibrotic diseases such as interstitial fibrosis, may be associated with subglottic stenosis. To study this hypothesis, we measured TGF-beta1 expression sequentially in 28 rats after posterior cricoid injury, using both standard immunohistochemistry and reverse transcriptase-polymerase chain reaction. In addition, an osmotic pump infused TGF-beta1 in 18 rats, normal saline solution in 9 rats, and neutralizing antibodies in 9 rats. Specimens were stained for fibronectin and procollagen at 1, 7, and 21 days and underwent optical density analysis. In the injured airway, TGF-beta1 expression peaked at 1 day and returned to baseline by 21 days. The TGF-beta1 infusion led to an increase in the expression of extracellular matrix proteins relative to controls. In contrast, neutralizing antibodies led to a decrease in extracellular matrix protein expression. These findings suggest that TGF-beta1 may possibly play a role in the pathogenesis of subglottic stenosis.

Use of intranasal fentanyl in children undergoing myringotomy and tube placement during halothane and sevoflurane anesthesia

BACKGROUND

Many children are restless, disoriented, and inconsolable immediately after bilateral myringotomy and tympanosotomy tube placement (BMT). Rapid emergence from sevoflurane anesthesia and postoperative pain may increase emergence agitation. The authors first determined serum fentanyl concentrations in a two-phase study of intranasal fentanyl. The second phase was a prospective, placebo-controlled, double-blind study to determine the efficacy of intranasal fentanyl in reducing emergence agitation after sevoflurane or halothane anesthesia.

METHODS

In phase 1, 26 children with American Society of Anesthesiologists (ASA) physical status I or II who were scheduled for BMT received intranasal fentanyl, 2 microg/kg, during a standardized anesthetic. Serum fentanyl concentrations in blood samples drawn at emergence and at postanesthesia care unit (PACU) discharge were determined by radioimmunoassay. In phase 2, 265 children with ASA physical status I or II were randomized to receive sevoflurane or halothane anesthesia along with either intranasal fentanyl (2 microg/kg) or saline. Postoperative agitation, Children's Hospital of Eastern Ontario Pain Scale (CHEOPS) scores, and satisfaction of PACU nurses and parents with the anesthetic technique were evaluated.

RESULTS

In phase 1, the mean fentanyl concentrations at 10 +/- 4 min (mean +/- SD) and 34 +/- 9 min after administering intranasal fentanyl were 0.80 +/- 0.28 and 0.64 +/- 0.25 ng/ml, respectively. In phase 2, the incidence of severe agitation, highest CHEOPS scores, and heart rate in the PACU were decreased with intranasal fentanyl. There were no differences between sevoflurane and halothane in these measures and in times to hospital discharge. The incidence of postoperative vomiting, hypoxemia, and slow respiratory rates were not increased with fentanyl.

CONCLUSIONS

Serum fentanyl concentrations after intranasal administration exceed the minimum effective steady state concentration for analgesia in adults. The use of intranasal fentanyl during halothane or sevoflurane anesthesia for BMT is associated with diminished postoperative agitation without an increase in vomiting, hypoxemia, or discharge times.

Incidence and prevalence of recurrent respiratory papillomatosis among children in Atlanta and Seattle

The incidence and prevalence of recurrent respiratory papillomatosis (RRP) for children aged <18 years were estimated in 2 US cities, Atlanta and Seattle, in 1996. All otolaryngologists in a 24-county area in metropolitan Atlanta (101 physicians) and an 8-county area in metropolitan Seattle (139 physicians) agreed to participate in the study. Medical record chart abstraction was performed only for children with documented current residence in the study area (21 patients in Atlanta and 14 patients in Seattle). The incidence rate for juvenile RRP was 1.11/100,000 population in Atlanta and 0.36/100, 000 in Seattle. The prevalence rate was 2.59/100,000 population in Atlanta and 1.69/100,000 in Seattle. In neither city did prevalences differ significantly when stratified by sex or race. Extrapolation of these estimates to the US population suggests that 80-1500 incident cases and 700-3000 prevalent cases of juvenile RRP will occur in the United States during 1999.

Pediatric angioedema: ten years' experience

OBJECTIVE

To clarify the cause, clinical course, and management of children with angioedema.

DESIGN

Retrospective review.

SETTING

Urban tertiary care hospital for children.

PATIENTS

Consecutive sample of all children hospitalized from January 1, 1987, to December 31, 1997, with the diagnosis of angioedema. Complete records permitting analysis were available for 10 patients.

MAIN OUTCOME MEASURES

Sex, age, site, symptoms at initial examination, cause, therapeutic management, and clinical outcome.

RESULTS

Seven boys and 3 girls, a mean age of 7.7 years, had angioedema of the head or neck, most often facial (8/10 [80%]). Manifesting symptoms, in addition to swelling, were tenderness or pain in 4 children (40%), dyspnea in 3 (30%), dysphagia (including drooling and spitting) in 3 (30%), and hoarseness in 1 (10%). Angioedema was due to food in 4 children (40%), insect bites in 3 (30%), infection in 2 (20%), and an antibiotic in 1 (10%). Treatment was pharmacological in all cases. No child required intubation or tracheotomy. Care in the intensive care unit was necessary for 1 child (10%).

CONCLUSIONS

Pediatric angioedema exhibits a different cause and clinical manifestations than does adult angioedema. Prompt diagnosis and early treatment with an intravenous corticosteroid, an antihistamine, and/or epinephrine lead to rapid resolution and may, in appropriately staffed settings, avoid the need for care in the intensive care unit or airway intervention. Management algorithms based on adult experience must be modified to account for the milder pediatric manifestations of this immunologic disease.

Graft healing in laryngotracheal reconstruction: an experimental rabbit model

The actual sequence of events in graft healing in laryngotracheal reconstruction (LTR) is not well understood. To investigate sequential changes in graft healing, we submitted 21 rabbits to LTR with an anterior auricular cartilage graft. They were immediately extubated after surgery, and no stent was used. Rabbits were painlessly sacrificed at 7 different time periods (0, 1, 2, 3, 4, 6, and 10 weeks after surgery). Cross sections of the larynx and graft were cut and stained with hematoxylin-eosin and trichrome. Epithelialization progressed very rapidly and was complete by 21 days. During the 10 weeks, there was a progressive necrosis and resorption of the original graft cartilage. However, neochondrification progressed very rapidly and resulted in excellent structural support of the graft in the airway. Problems, such as infection and granulation tissue formation, were relatively minor and infrequent.

Internal carotid artery narrowing in children with retropharyngeal lymphadenitis and abscess

BACKGROUND AND PURPOSE

Our purpose was to describe the association between narrowing of the internal carotid artery (ICA) and retropharyngeal abscess in children.

METHODS

Neck CT scans from 13 consecutive children with suppurative retropharyngeal lymphadenitis and abscess were evaluated retrospectively for asymmetric ICA diameters at the level of the abscess. Clinical status at the time of illness was established via a chart review. Twenty control CT scans obtained from pediatric patients with normal imaging findings were evaluated prospectively to determine symmetry and size of the ICA.

RESULTS

Mean diameter of the normal ICA, contralateral to the retropharyngeal abscess, was 5 mm (range, 3-8 mm), while mean diameter ipsilateral to the abscess was 3 mm (range, 1-5 mm). The diameters of the normal and abnormal ICAs were statistically significantly different. All children were neurologically normal. The right and left ICAs in children with normal CT findings in the neck were symmetrical in diameter.

CONCLUSION

Despite dramatic narrowing of the ICA ipsilateral to retropharyngeal lymphadenitis and abscess, no children in this series had neurologic deficits, suggesting that such narrowing is a common, benign, and, most likely, incidental imaging finding.

Tracheostomy decannulation in children: approaches and techniques

Various approaches and techniques are used in discontinuing tracheostomy in children. The variability in the use of resources is considerable. The objective of this study was to assess decannulation in children attended in a university-affiliated children's hospital. A retrospective analysis was made of the medical records of patients who had both tracheostomy (n = 177) and decannulation (n = 30) from 1985 to 1994. Tracheostomies, placed at a mean age of 38 months, were discontinued (on the average) 22 months later. Most children underwent airway endoscopy in the operating room in preparation for decannulation. Twenty-four children had downsizing, then capping of the tracheostomy as a functional trial. Six children underwent staged laryngotracheoplasty before decannulation. Two children had decannulation as part of a single-stage laryngotracheoplasty. Attention to at least one comorbid factor (e.g., pulmonary, neurologic, or cardiac disease) was important in the decannulation of each patient in this series. The individualization of tracheostomy decannulation is necessary for children.

Management of nasopharyngeal and oropharyngeal stenosis in children

Nasopharyngeal stenosis and oropharyngeal stenosis are rare and challenging problems in the pediatric population. The most common etiology is currently the surgical trauma associated with adenotonsillectomy. Stenosis can vary from a thin band to a complete obstructing cicatrix. Presenting symptoms range from mild hyponasal speech to severe airway obstruction. We present a series of eight children with varying degrees of stenosis and associated symptoms. Choice of treatment varied with the severity of disease. In our series, successful interventions included triamcinolone acetonide injection, lysis of adhesions, rotational and advancement mucosal flaps, and jejunal free flap. Preoperative evaluation and individualized surgical repair are essential for successful treatment.

Pulmonary vascular complications of chronic airway obstruction in children

OBJECTIVE

To study the clinical presentation, treatment, and outcome of pulmonary artery hypertension (PAH) that develops in children with chronic airway obstruction.

DESIGN

Case study.

SETTING

Academic tertiary care children's hospital.

PATIENTS

A 3-year (October 1, 1992, to September 30, 1995) review of the medical records of all children with chronic airway obstruction in whom PAH developed.

MAIN OUTCOME MEASURE

The clinical course, including objective laboratory data to measure PAH (cardiac catheterization, echocardiography, electrocardiography) both before and after treatment.

RESULTS

Pulmonary artery hypertension developed in 18 patients. It was diagnosed using cardiac catheterization in 13 patients and echocardiography in 5 patients. Obstructive problems include chronic lung disease (9 patients), tracheobronchomalacia (6 patients), adenotonsillar hypertrophy (5 patients), laryngomalacia (4 patients), macroglossia (5 patients), subglottic stenosis (2 patients), and pharyngeal collapse (2 patients). Nine patients were born prematurely and 7 had Down syndrome. Treatments included tracheotomy (7), adenotonsillectomy (5), adenoidectomy (3), laser epiglottoplasty (1), and supplemental oxygen (12). Fourteen patients had documented improvement of PAH as seen from the cardiac catheterization, echocardiography, or electrocardiography findings; in 4 patients, PAH worsened (3 deaths).

CONCLUSIONS

Chronic airway obstruction may lead to PAH. In this study, PAH was more likely to develop in premature infants or children with Down syndrome and cardiac anomalies. Surgery or supplemental oxygen will usually improve PAH, but fixed and irreversible PAH developed in patients with the most severe airway disease.

Upper airway obstruction in children with Down syndrome

OBJECTIVES

To analyze the complex nature of upper airway obstruction (UAO) and the response to surgery in children with Down syndrome.

DESIGN

Retrospective medical chart review of all patients with Down syndrome who had UAO during a 5-year period.

SETTING

Academic tertiary care children's hospital.

PATIENTS

Seventy-one pediatric patients with Down syndrome who had significant UAO. Thirty-four patients had pulmonary artery hypertension; 44 patients had multiple sites of airway obstruction. The obstructive problems included lymphoid hyperplasia, macroglossia, narrow nasopharynx, laryngomalacia, congenital subglottic stenosis, tracheobronchomalacia, and tracheal stenosis.

INTERVENTIONS

Children with Down syndrome and UAO underwent surgical procedures including tonsillectomy, adenoidectomy, tonsillar pillar plication, uvulopalatopharyngoplasty, anterior tongue reduction, tonguehyoid suspension, laryngotracheoplasty, and tracheotomy.

MAIN OUTCOME MEASURES

Postoperative symptoms found on medical chart review, or parental telephone survey, or both, and results of postoperative diagnostic tests. Patients were grouped as "improved" or having "significant residual symptoms."

RESULTS

Twenty-seven of the 55 surgical patients had mild obstructive symptoms, and most improved after tonsil or adenoid surgery, or both. The remaining patients were younger and had more severe symptoms, multiple sites of obstruction, and a high incidence of cardiac disease. Eleven (39%) of the 28 patients in this group had significant residual symptoms after surgery. Four children are tracheotomy-dependent. Five deaths occurred; 3 were attributable to the upper airway.

CONCLUSIONS

Upper airway obstruction in children with Down syndrome often is a complex process with multifocal causes. Residual symptoms of airway obstruction are common after surgery. A comprehensive and individualized approach is important in the management of UAO in Down syndrome.

Vocal cord injection in children with unilateral vocal cord paralysis

Unilateral vocal cord paralysis (UVCP) in children is uncommon and rarely leads to serious sequelae. However, on rare occasions, it can present with severe aspiration and dysphonia. Several therapeutic techniques have been used in adults with UVCP, but the reported alternatives in children have been much more limited. Observation and speech therapy are the standard treatment. We describe three children with UVCP and severe aspiration who were treated with vocal cord injection. The treatment indications, clinical courses, and outcomes of the three cases are detailed. The injection of vocal cords in children is discussed, with an emphasis on those aspects unique to the management of UVCP in pediatric patients. Alternative surgical treatment modalities are also presented. Vocal cord injection is an effective and viable therapeutic option for the management of UVCP in certain pediatric patients with severe aspiration and dysphonia.

Glomus tympanicum in infancy

A glomus tympanicum tumor, limited to the cochlear promontory, was excised from the middle ear of a 6-month-old girl. To our knowledge, there have been no reports of temporal bone paragangliomas occurring at a younger age. Diagnosis, therapy, and the special characteristics of pediatric glomus tumors are discussed.

Tracheobronchomalacia in children

Tracheobronchomalacia (TBM) is an important cause of airway distress during infancy, but it generally resolves as the airway enlarges. To assess the origin and natural history of TBM, a chart review and telephone survey were conducted for 50 patients with TBM at the Children's Hospital of Philadelphia (Pa). This study revealed that TBM is a relatively common airway abnormality and is found on 15% of all diagnostic bronchoscopies. Prematurity, low birth weight, bronchopulmonary dysplasia, and prolonged ventilation predispose patients to the most severe symptoms. In our study, a tracheotomy with continuous positive airway pressure was required by 75% of the premature infants and 25% of the full-term infants with TBM. Seventy-one percent of all patients underwent decannulation without any other surgical intervention and remained nearly asymptomatic. Some patients could not undergo decannulation because of other airway lesions. In most instances, TBM is a self-limited disease that resolves without surgery.

Reinnervation of the canine posterior cricoarytenoid muscle with sympathetic preganglionic neurons

This experiment investigated the reinnervation of the canine posterior cricoarytenoid (PCA) muscle with preganglionic neurons of the sympathetic nervous system. Six dogs had their right recurrent laryngeal nerve (RLN) sectioned. Four of these dogs had the sympathetic cervical trunk (SCT) implanted into the right PCA muscle, and the two remaining dogs served as denervated controls. Four months later all dogs underwent videolaryngoscopy, electromyography, and electrical stimulation of the SCT. The PCA muscles were excised, sectioned, and stained for glycogen and ATPase. All four experimental PCA muscles demonstrated electrically evoked abduction and tonic electromyographic activity. In two of the specimens, staining (ATPase and PAS) revealed areas of reinnervation with fiber type grouping and glycogen depletion. These results are consistent with the successful reinnervation of the PCA muscle. Further refinement of this technique could be of benefit to patients with bilateral vocal cord paralysis.