Distinct patterns of respiratory difficulty in young children with achondroplasia: a clinical, sleep, and lung function study

AIM: Achondroplasia can result in respiratory difficulty in early infancy. The aim of this study was to document lung growth during infancy, together with the cause of any cardiorespiratory and sleep dysfunction. PATIENTS AND METHODS: Seventeen prospectively ascertained infants (14 boys and three girls) with respiratory symptoms starting before 1 year of age underwent clinical, sleep, and lung function studies. RESULTS: Three distinct groups were identified. Group 1 (n = 6) were the least symptomatic and only had obstructive sleep apnoea. Group 2 (n = 6) had obstructive sleep apnoea of muscular aetiology and, neurologically, hydrocephalus and a small foramen magnum were common. Group 3 (n = 5), the most severely affected group, all developed cor pulmonale, with three deaths occurring as a result of terminal cardiorespiratory failure. All five had obstructive sleep apnoea with a muscular aetiology (a small foramen magnum predominated) with severe or moderately severe gastro-oesophageal reflux. Initially, lung function studies found no evidence of restriction or reduced lung volumes standardised according to weight. However, with growth these infants had worsening function, with raised airway resistance and severe reductions in respiratory compliance. CONCLUSIONS: These groups appear to be distinct phenotypes with distinct anatomical aetiologies: "relative" adenotonsillar hypertrophy, resulting from a degree of midfacial hypoplasia (group 1); muscular upper airway obstruction along with progressive hydrocephalus, resulting from jugular foramen stenosis (group 2); and muscular upper airway obstruction, but without hydrocephalus, resulting from hypoglossal canal stenosis with or without foramen magnum compression and no jugular foramen stenosis (group 3). The aetiology of these abnormalities is consistent with localised alteration of chondrocranial development: rostral, intermediary and caudal in groups 1, 2, and 3, respectively.     

Distinct patterns of respiratory difficulty in young children with achondroplasia: a clinical,sleep, and lung function study

AIM—Achondroplasia can result in respiratory difficulty in early infancy. The aim of this study was to document lung growth during infancy, together with the cause of any cardiorespiratory and sleep dysfunction.PATIENTS AND METHODS—Seventeen prospectively ascertained infants (14 boys and three girls) with respiratory symptoms starting before 1 year of age underwent clinical, sleep, and lung function studies.RESULTS—Three distinct groups were identified. Group 1 (n = 6) were the least symptomatic and only had obstructive sleep apnoea. Group 2 (n = 6) had obstructive sleep apnoea of muscular aetiology and, neurologically, hydrocephalus and a small foramen magnum were common. Group 3 (n = 5), the most severely affected group, all developed cor pulmonale, with three deaths occurring as a result of terminal cardiorespiratory failure. All five had obstructive sleep apnoea with a muscular aetiology (a small foramen magnum predominated) with severe or moderately severe gastro-oesophageal reflux. Initially, lung function studies found no evidence of restriction or reduced lung volumes standardised according to weight. However, with growth these infants had worsening function, with raised airway resistance and severe reductions in respiratory compliance.CONCLUSIONS—These groups appear to be distinct phenotypes with distinct anatomical aetiologies: "relative" adenotonsillar hypertrophy, resulting from a degree of midfacial hypoplasia (group 1); muscular upper airway obstruction along with progressive hydrocephalus, resulting from jugular foramen stenosis (group 2); and muscular upper airway obstruction, but without hydrocephalus, resulting from hypoglossal canal stenosis with or without foramen magnum compression and no jugular foramen stenosis (group 3). The aetiology of these abnormalities is consistent with localised alteration of chondrocranial development: rostral, intermediary and caudal in groups 1, 2, and 3,respectively.     

Sleep apnea

Objective To study clinical presentation of sleep disordered breathing (SDB) in children, their causative factors and response to treatment. Methods A retrospective study of clinical data nd results of overnight polysomnography done at baseline and after therapy were reviewed in 56 patients under 18 years of age. Results Of the 56 patients included in the study 23(41%) cases were positive for SDB. 12 (52.1%) patients had craniofacial abnormalities, 4 (17.3%) had neuromuscular and skeletal disorders, 2 (8.6%) had adenotonsillar hypertrophy, 1 (4.3%) had bilateral vocal cord palsy and 3 (13%) had sleep apnoea associated with multisystemic disorders. Post-operative data showed improvement in all 6 cases of craniofacial abnormalities and both cases of adenotonsillar hypertrophy. Positive airway pressure treatment was useful in cases with obstructive sleep apnea (OSA) due to vocal cord palsy, theracic scoliosis, systemic disorders and central hypoventilation. Conclusion 41% of suspected cases were detected to have SDB. Craniofacial abnormality was the leading cause of OSA in the present study. Surgical correction improved symptoms apnea-hypopnea index (AHI) and desaturation in cases of craniofacial disorders and adenotonsillar hypertrophy. Vocal cord palsy thoracic scoliosis, hypoventilation and systemic disorders associated OSA responded to positive airway pressure ventilation.     

Pediatric obstructive sleep apnea syndrome and anesthetic management

Sleep-related breathing disorders require special attention in children who spend a considerable time sleeping. Obstructive sleep apnea syndrome is characterized by episodes of upper airway obstruction during sleep. Symptoms include hyperactivity, enuresis, headache, failure to thrive, and increased respiratory effort and total sleep time. The most common cause is adenotonsillar hypertrophy. Coexisting diseases are obesity, neuromuscular and craniofacial anomalies, and Down's syndrome. Early diagnosis is important to minimize neurocognitive, cardiac and developmental complications. Polysomnography is the gold standard for diagnosis. Although the features of pediatric obstructive sleep apnea syndrome are distinctly different from that in adults, it may predispose to the adult type of the syndrome. As therapy concerns several surgical approaches as well as conservative techniques, anesthetic management calls for particular attention. Pre- and postoperative sedation must be performed cautiously and patients must be watched closely with respect to airway obstruction and hypoventilation. Difficult intubation must always be considered.     

Nocturnal hypoventilation in children with nonprogressive neuromuscular disease

Eight patients between 4 and 24 years of age with nonprogressive neuromuscular disease sought medical attention because of severe nocturnal hypoventilation. There were two types of findings: subacute with progressive early morning headaches and daytime drowsiness and acute with ventilatory failure and cor pulmonale. Seven patients were ambulant. Seven were successfully treated with either a cuirass negative pressure ventilator or a positive pressure ventilator via a tracheostomy. The ventilatory assistance was only used at night and resulted in rapid resolution of early morning symptoms and a return to full daytime activity. One patient died as a result of an intercurrent respiratory infection before respiratory support could be given. It is important to be aware of this potentially life-threatening complication in patients with an otherwise good prognosis and of the benefit to be derived from active treatment.     

Glossoptosis-apnea syndrome in infancy

The clinical and physiologic features of 28 infants with Pierre Robin syndrome and those of 20 infants with various types of nasal obstruction were reviewed to determine whether different causes of upper airway obstructure may lead to a common syndrome. The patients had no significant differences in distribution of main clinical manifestations. Their features included cyanosis with respiratory distress, apneic spells, oropharyngeal dysphagia, vomiting, failure to thrive, cor pulmonale, brain damage, and sudden death during sleep. The common physiologic manifestation appeared to be an oropharyngeal obstruction caused by glossoptosis, which occurred mainly during wakefulness. Upper airway obstruction led to hypoxemia, which, in many instances, was not associated with hypercapnia and was not relieved by oxygen administration. It is concluded that regardless of a specific cause, any airway obstruction that results in a decreased inspiratory pressure overcoming the airway maintaining genioglossus action causes a glossoptosis-apnea syndrome.     

Hurler's syndrome with cor pulmonale secondary to obstructive sleep apnoea treated by continuous positive airway pressure

A 6-year-old boy with Hurler's syndrome presented with right heart failure and pulmonary hypertension secondary to severe obstructive sleep apnoea. Both his sleep apnoea and cor pulmonale were effectively controlled with continuous positive airway pressure therapy.     

Evaluation of epiglottoplasty as treatment for severe laryngomalacia

Six patients with severe laryngomalacia underwent epiglottoplasty. Four of these patients had life-threatening episodes of airway obstruction before surgery; of these, two had required tracheal intubation and one had required cardiopulmonary resuscitation. Two patients had failure to thrive and two had cor pulmonale. Patients had required a mean of two hospitalizations related to upper airway obstruction. We performed polysomnography during a daytime nap, both before and after epiglottoplasty, in all patients. Respiratory effort, arterial oxygen saturation, and end-tidal carbon dioxide pressure were monitored with continuous electrocardiograms and electrooculograms. All patients had abnormal polysomnograms preoperatively. Six patients had obstructive apnea, four had hypoxemia (arterial oxygen saturation less than 90% while breathing room air), and four had hypoventilation (end-tidal carbon dioxide pressure greater than 45 mm Hg) before epiglottoplasty. Mean age (+/- SEM) at epiglottoplasty was 10.3 +/- 5.3 months. No patients had surgical complications. An endotracheal tube was in place for 25 +/- 7 hours postoperatively, and patients were discharged 4 +/- 1 days postoperatively. Polysomnography performed 2.8 +/- 1.0 months after surgery showed that all patients had improved. Two patients had residual, mild episodes of obstructive apnea, and one patient had mild hypoventilation and desaturation. No patient had further life-threatening events or required further hospitalizations after epiglottoplasty. We conclude that epiglottoplasty is an effective and safe treatment for a selected group of patients with severe laryngomalacia.     

CONGENITAL CENTRAL HYPOVENTILATION SYNDROME TREATED WITH DIAPHRAGM PACING

ABSTRACT. Congenital central hypoventilation syndrome was diagnosed in an infant who since birth had shallow respiration and CO₂ retention during sleep, absent ventilatory response to hypercarbia, and no underlying disease or trauma to account for the symptoms. Diaphragm pacing was started at the age of 81/2 months and has been successfully carried out at home, guided by end-tidal CO₂ monitoring. After 22 months of home treatment, at the age of two years 9 months, linear growth and psychomotor development are progressing normally, while previous symptoms of cor pulmonale have not progressed.     

Upper airway lesions in children after accidental ingestion of caustic substances

Of 33 children admitted within 24 hours after accidental ingestion of a caustic substance, 14 (42.5%) had evidence of upper airway lesions on direct laryngoscopy. Three patients, 10 to 12 months old, needed endotracheal intubation for acute respiratory obstruction; four patients younger than 2 years had severe dyspnea without obstruction; seven patients had mild or no respiratory symptoms. All were discharged without respiratory sequelae, although esophageal stenosis developed in six patients. Nine of 13 patients younger than 2 years, compared to five of 20 patients older than 2 years, had upper airway lesions (P less than 0.01). The frequency of respiratory tract lesions was higher in patients with severe esophagitis. Eleven of 17 patients with severe esophagitis, compared to three of 16 with mild inflammation, had respiratory tract lesions (P less than 0.025). No specific caustic substance predisposed to upper airway lesions.     

Diagnostik und Therapie der Pierre-Robin-Sequenz

The Pierre Robin sequence (PRS) describes the combination of mandibular micrognathia and/or retrognathia with glossoptosis resulting in upper airway obstruction. If untreated complications such as failure to thrive, chronic hypoxemia and cor pulmonale may occur. Hence, PRS should be diagnosed early and the expression as well as severity of the breathing disorder assessed in a sleep laboratory. Because non-invasive alternatives have been lacking until recently, surgical interventions, such as glossopexy, wire extension and osteodistraction of the mandible are still widely used in infants. In a validated interdisciplinary non-invasive treatment protocol, a custom-made palatal plate with a velar extension (i.e. pre-epiglottic baton plate) which removes the airway obstruction and supports mandibular growth is used. Treated appropriately, children with isolated PRS show normal development whereas in syndrome-associated PRS the prognosis depends on the underlying diagnosis.     

Endoscopic supraglottoplasty in children with severe laryngomalacia with and without neurological impairment

OBJECTIVE: To describe indications and results of supraglottoplasty for severe laryngomalacia in children with or without neurological impairment. METHODS: Eight children with severe laryngomalacia submitted to endoscopic supraglottoplasty were retrospectively studied. Four had neurological impairment (male, mean age 6 years), and 4 did not present neurological problems (3 female, mean age 11.5 months). Surgery indications were respiratory distress, feeding difficulties, failure to thrive, and low oxygen saturation. Polysomnographic evaluation was carried out on the last 2 children, showing abnormal oxygen saturation, obstructive apnea, and hypoventilation. All children received preoperative antibiotics and corticosteroids. RESULTS: All children without neurological impairment had significant relief of symptoms. Children with neurological impairment had different outcome: one needed tracheotomy immediately after surgery due to edema and supraglottic granulation tissue. The other three children presented initial relief of symptoms, but subsequent follow-up showed progressive airway obstruction: one needed another endoscopic surgery 6 months later; other needed tracheotomy 7 months later. The children who were not submitted to tracheostomy presented persistent severe airway obstruction. No endoscopic surgery complication was observed. CONCLUSIONS: 1) Endoscopic supraglottoplasty is well tolerated and does not present complications when used in children; 2) Endoscopic supraglottoplasty was efficient in the treatment of children with severe laryngomalacia and in without neurological impairment; however, supraglottoplasty did not resolve airway obstruction in children with neurological impairment.     

Improved outcome in Pierre Robin sequence: effect of multidisciplinary evaluation and management

Infants with complications of Pierre Robin sequence are at increased risk of airway obstruction and resultant hypoxia, cor pulmonale, failure to thrive, and cerebral impairment. In an effort to minimize such complications, patients with Pierre Robin sequence were examined prospectively by a multidisciplinary team using polysomnography and continuous oximetry. Obstructive apnea and desaturation occurred in 18 of the 21 patients studied. Four children required only home apnea monitoring, and six required only monitoring and supplemental oxygen. Seven children had lip-tongue adhesion procedures performed, and four required tracheostomy. No patients died. All patients with isolated Pierre Robin sequence had normal development at follow-up except for one child who had experienced a respiratory arrest before referral. With improvements in neonatal intensive care, testing for respiratory assessment, improved surgical and postoperative intervention and home monitoring, the morbidity and mortality for children with Pierre Robin sequence can be reduced markedly.     

Using continuous nasal airway pressure in infants with craniofacial malformations

Obstructive sleep apnea (OSA) is common in infants and children with craniofacial malformations. Continuous positive airway pressure (CPAP) represents an effective noninvasive treatment for severe upper airway obstruction in these children, reducing the need of surgery or a tracheostomy. The decision to start CPAP should be discussed by a multidisciplinary team in order to decide the optimal individualized treatment strategy. CPAP initiation depends on patients’ clinical characteristics and local practices, with an increase tendency towards an outpatient program. Follow-up and monitoring strategy varies among centers but benefits from the analysis of built-in software data in order to assess objective adherence and breathing parameters, reducing the need of in-hospital sleep studies. The possibility to wean CPAP should be periodically checked after surgical treatment or when spontaneous resolution is suspected. Finally, these infants with craniofacial malformations should have a long term follow up because of the risk of OSA recurrence over time.     

Unsuspected cardiopulmonary abnormalities complicating bronchopulmonary dysplasia.

Bronchopulmonary dysplasia is a serious chronic lung disease of infancy but despite numerous problems such as poor growth, recurrent lower respiratory tract infections, and cor pulmonale, steady improvement and recovery may generally be expected. We report four infants with bronchopulmonary dysplasia in whom the cardiopulmonary course did not show the usual steady improvement. Each infant was found to have an unsuspected cardiopulmonary lesion in addition to lung disease: two had congenital heart disease and two upper airway obstruction. Three improved after surgical intervention but one patient died immediately after this. Persistent right ventricular hypertrophy in patients with bronchopulmonary dysplasia maintained on supplemental oxygen, and a particularly slow rate of recovery from the need for supplemental oxygen are markers that should lead to evaluation for coexisting cardiopulmonary abnormalities.     

Congenital central hypoventilation syndrome: diagnosis, management, and long-term outcome in thirty-two children.

The diagnosis, management, and long-term outcome of 32 patients with congenital central hypoventilation syndrome are summarized. Sleep hypoventilation was severe in all cases, resulting in an alveolar carbon dioxide pressure (mean +/- SEM) of 62 +/- 2.5 mm Hg and a hemoglobin saturation of 65% +/- 3.3% without ventilatory or arousal response. Awake hypoventilation on initial assessment was present in 12 of the 32 patients, resulting in an alveolar carbon dioxide pressure of 58 +/- 2.2 mm Hg and a hemoglobin saturation of 59% +/- 7%. Associated conditions included pulmonary hypertension or cor pulmonale or both (78%), heart block and sick sinus syndrome requiring a cardiac pacemaker (two patients), mild atrophy by cranial imaging evidence (40%), seizures (72%), normal brain-stem auditory evoked responses in all but one patient tested, ganglioneuroblastomas (one patient), Hirschsprung disease (16%), and ophthalmologic abnormalities (60%). Growth was deficient in 44% of patients; hypotonia or major motor delay or both were apparent in all. Twenty-two patients are living; 12 of them require continuous ventilatory support and 10 breathe spontaneously while awake and require ventilatory support while asleep. Ten patients have died. Autopsy performed in six cases indicated diffuse central nervous system astrocytosis, gliosis, and atrophy but no primary brain-stem abnormality. Although these data support a diffuse central nervous system process, the specific cause and the mode of inheritance remain unclear. With early diagnosis and careful ventilatory management, the sequelae of hypoxia and morbidity should be minimized and long-term outcome improved.     

Obstructive sleep apnea in children with Down syndrome.

Children with Down syndrome have many predisposing factors for the obstructive sleep apnea syndrome (OSAS), yet the type and severity of OSAS in this population has not been characterized. Fifty-three subjects with Down syndrome (mean age 7.4 +/- 1.2 [SE] years; range 2 weeks to 51 years) were studied. Chest wall movement, heart rate, electroculogram, end-tidal PO2 and PCO2, transcutaneous PO2 and PCO2, and arterial oxygen saturation were measured during a daytime nap polysomnogram. Sixteen of these children also underwent overnight polysomnography. Nap polysomnograms were abnormal in 77% of children; 45% had obstructive sleep apnea (OSA), 4% had central apnea, and 6% had mixed apneas; 66% had hypoventilation (end-tidal PCO2 greater than 45 mm Hg) and 32% desaturation (arterial oxygen saturation less than 90%). Overnight studies were abnormal in 100% of children, with OSA in 63%, hypoventilation in 81%, and desaturation in 56%. Nap studies significantly underestimated the presence of abnormalities when compared to overnight polysomnograms. Seventeen (32%) of the children were referred for testing because OSAS was clinically suspected, but there was no clinical suspicion of OSAS in 36 (68%) children. Neither age, obesity, nor the presence of congenital heart disease affected the incidence of OSA, desaturation, or hypoventilation. Polysomnograms improved in all 8 children who underwent tonsillectomy and adenoidectomy, but they normalized in only 3. It is concluded that children with Down syndrome frequently in have OSAS, with OSA, hypoxemia, and hypoventilation. Obstructive sleep apnea syndrome is seen frequently in those children in whom it is not clinically suspected. It is speculated that OSAS may contribute to the unexplained pulmonary hypertension seen in children with Down syndrome.     

Inflammatory measures in children with obstructive sleep apnoea

AIM: To evaluate a range of inflammatory measures in children with obstructive sleep apnoea (OSA). METHODS: In total, 44 children with polysomnographically defined OSA (30 boys; mean age: 7.3 +/- 3.7 years) and 69 control subjects (44 boys; mean age: 7.6 +/- 4 years) were recruited. Controls were screened for symptoms of OSA by questionnaire at the time of elective surgery that was unrelated to the upper airway. Blood samples were analysed for C-reactive protein, and cytokines IL-1beta, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, GM-CSF, IFN-gamma and TNF-alpha. RESULTS: The majority of the children had mild OSA (32/44). Children with OSA (respiratory disturbance index 5.3 +/- 6.5 events/h) had significantly higher IFN-gamma and IL-8 levels than controls (P < 0.001 and 0.003, respectively), although correction for age, sex and body mass index reduced these differences (IFN-gammaP = 0.002, and IL-8 P = 0.051). There were no significant correlations between inflammatory measures and body mass index, respiratory disturbance index, or other sleep, desaturation, or arousal parameters including respiratory or spontaneous arousal indices, desaturation index or severity, sleep efficiency, or apnoea/hypopnoea duration in the OSA group. CONCLUSION: Children with OSA, even of mild severity, have significantly elevated IFN-gamma levels and a trend towards elevated IL-8 levels compared with asymptomatic controls, consistent with a pro-inflammatory effect of OSA. These changes seen in mild OSA may precede changes in other pro-inflammatory cytokines found in studies of adults with more severe and long-standing disease, implying a potential benefit from early disease identification and intervention.     

Airway management in children with cleft palate and/or micrognathia

Cleft lip and/or palate is the commonest congenital craniofacial abnormality affecting approximately 1 in 700 newborns each year. It comprises of a heterogenous group of disorders affecting facial growth and cosmesis, that are associated with increased risk of airway obstruction, sleep disordered breathing (SDB), glue ear and chronic ear disease, feeding difficulties, and failure to thrive (FTT). Cleft palate (CP) can be accompanied by an abnormally undersized jaw, known as micrognathia; although micrognathia can also be found in isolation. The craniofacial abnormalities found in these children can lead to a reduction in airway size due to the tongue falling backwards. The risk of airway obstruction ranges from intermittent airway collapse during sleep (obstructive sleep apnoea, OSA) to potentially life-threatening airway compromise necessitating intubation or a tracheostomy. This paper sets out to describe the pathophysiology of airway compromise in these children, recognising clinical symptoms and appropriate referral strategy, as well as a broad range of management options.     

Control of breathing in the central alveolar hypoventilation syndrome with and without a phrenic pacemaker

Primary central alveolar hypoventilation (CAHV) is a rare disorder described in newborns, children, and adults. We report a 2 9/12 year old child with CAHV of unknown etiology. The evaluation of her ventilatory control system showed abnormalities awake and in the different sleep states. Hypoventilation was found to be more severe during non-REM sleep than during REM sleep and awake state. She had central apnea, an irregular respiratory rhythm in the non-REM sleep too, and diminished ventilatory response to inhaled 5%-6% CO2 in both REM and non-REM sleep. Her ventilation decreased when she was breathing 50% and 100% oxygen. During breathing 15% oxygen she did not arouse in spite a transcutaneous pO2 of 10 mmHg. She was first treated with mechanical ventilation during sleep and has now received bilateral simultaneous phrenic pacemaker support during quiet sleep for about one year. With the phrenic pacemaker she has normal minute volume and transcutaneous blood gases during sleep. During a respiratory infection she needed again mechanical ventilation via her tracheostoma 24 hours a day for one week. This case of a CAHV demonstrates a dysfunction of the central and partially also of the peripheral chemoreceptors. The abnormalities of the ventilation were demonstrable not only in the non-REM sleep but also in the REM sleep and awake state.