Decannulation in children affected by congenital central hypoventilation syndrome: A proposal of an algorithm from two European centers

Congenital central hypoventilation syndrome in korea: 20 years of clinical observation and evaluation of the ventilation strategy in a single center

Congenital central hypoventilation syndrome (CCHS) is a rare genetic disorder characterized by hypoventilation due to impaired breathing control by the central nervous system and other symptoms of autonomic dysfunction. Mutations in paired-like homeobox 2 B (PHOX2B) are responsible for most cases of CCHS. Patients with CCHS have various phenotypes and severities, making the diagnosis difficult. This study aimed to present a comprehensive single-center experience of patients with CCHS, including key clinical features, treatment strategies, and outcomes. A retrospective chart review was performed for patients diagnosed with CCHS between January 2001 and July 2023 at Seoul National University Children's Hospital. Finally, we selected 24 patients and collected their demographic data, genotypes, ventilation methods, and clinical features related to autonomic dysfunction. The relationship between the clinical manifestations and genotypes was also examined. All patients used home ventilators, and tracheostomy was performed in 87.5% of patients. Fifteen (62.5%) patients had constipation and nine (37.5%) were diagnosed with Hirschsprung disease. Arrhythmia, endocrine dysfunction, and subclinical hypothyroidism were present in nine (37.5%), six patients (25.0%), and two patients (16.7%), respectively. A significant number of patients exhibited neurodevelopmental delays (19 patients, 79.2%). There was a correlation between the phenotype and genotype of PHOX2B in patients with CCHS. (r = 0.71, p < 0.001).   Conclusion: There was a positive correlation between paired-like homeobox 2 B mutations (especially the number of GCN repeats in the polyalanine repeat mutations sequence) and clinical manifestations. This study also demonstrated how initial treatment for hypoventilation affects neurodevelopmental outcomes in patients with CCHS. What is Known: • Congenital central hypoventilation syndrome is a rare genetic disorder characterized by hypoventilation and dysfunction of autonomic nervous system. • The disease-defining gene of CCHS is PHOX2B gene - most of the cases have heterozygous PARMs and the number of GCN triplets varies among the patients(20/24 - 20/33). What is New: • We have noted in the Korean patients with CCHS that there is a correlation between genotype (number of GCN repeats) and severity of phenotype. • National support for rare diseases allowed for a prompter diagnosis of patients with CCHS in Korean population.

Pediatric tracheostomy decannulation: what's the evidence?

PURPOSE OF REVIEW

Pediatric decannulation failure can be associated with large morbidity and mortality, yet there are no published evidence-based guidelines for pediatric tracheostomy decannulation. Tracheostomy is frequently performed in medically complex children in whom it can be difficult to predict when and how to safely decannulate.

RECENT FINDINGS

Published studies regarding pediatric decannulation are limited to reviews and case series from single institutions, with varying populations, indications for tracheostomy, and institutional resources. This article will provide a review of published decannulation protocols over the past 10 years. Endoscopic airway evaluation is required to assess the patency of the airway and address any airway obstruction prior to decannulation. There is considerable variability in tracheostomy tube modification between published protocols, though the majority support a capping trial and downsizing of the tracheostomy tube to facilitate capping. Most protocols include overnight capping in a monitored setting prior to decannulation with observation ranging from 24 to 48 h after decannulation. There is debate regarding which patients should have capped polysomnography (PSG) prior to decannulation, as this exam is resource-intensive and may not be widely available. Persistent tracheocutaneous fistulae are common following decannulation. Excision of the fistula tract with healing by secondary intention has a lower reported operative time, overall complication rate, and postoperative length of stay.

SUMMARY

Pediatric decannulation should occur in a stepwise process. The ideal decannulation protocol should be safe and expedient, without utilizing excessive healthcare resources. There may be variability in protocols based on patient population or institutional resources, but an explicitly described protocol within each institution is critical to consistent care and quality improvement over time. Further research is needed to identify selection criteria for who would most benefit from PSG prior to decannulation to guide allocation of this limited resource.

Tracheostomy decannulation in children: a proposal for a structured approach on behalf of the working group chronic respiratory insufficiency within the German-speaking society of pediatric pulmonology

The number of children with tracheostomies with and without home mechanical ventilation has grown continuously in recent years. For some of these children, the need for tracheostomy resolves and the child can be weaned from the tracheal cannula. Choosing the optimal time point for decannulation after elaborated prior diagnostic work-up needs careful consideration. The decannulation process requires an interdisciplinary team; however, these specialized structures for the experienced care of these children with tracheostomy are not available in all areas. The Working Group on Chronic Respiratory Insufficiency in the German Speaking Pediatric Pneumology Society (GPP) developed these recommendations to guide through a decannulation process. Initial evaluation of decannulation feasibility starts in the outpatient clinic with a detailed history, examination, and a speaking valve trial and is followed by an inpatient workup including sleep study, airway endoscopy and possibly modifications of the tracheal cannula. Downsizing the tracheal cannula allows a stepwise controlled weaning prior to removal of the tracheal cannula. After shrinking of the tracheostomy, the final surgical closure is performed.  Conclusion: An algorithm with diagnostic and therapeutic procedures for a safe and successful decannulation process is proposed. What is Known: • In children tracheostomy decannulation is a complex process that requires careful preparation and surveillance. What is New: • This statement of the German speaking society of pediatric pulmonology provides an expert practice guidance on the decannulation procedure and the value of one-way speaking valves.

Congenital central hypoventilation syndrome: a life-threatening cause of neonatal apnoea

Congenital central hypoventilation syndrome (CCHS) is an uncommon genetic disease characterised by an autonomic nervous system dysfunction that affects ventilatory homeostasis. Involvement of other systems is also described, mainly cardiovascular, gastrointestinal and central nervous systems. We describe a rare case of CCHS diagnosed in a term newborn who presented with persistent apnoea in the first hours of life. After an exhaustive aetiological study excluding primary pulmonary, cardiac, metabolic and neurological diseases, this diagnosis was confirmed by a paired-like homeobox 2B gene sequence analysis. During hospitalisation, ventilation was optimised and multidisciplinary follow-up was initiated, including genetic counselling. At 2 months old, the child was discharged under non-invasive ventilation during sleep. This case illustrates the importance of early diagnosis, including genetic study and advances in home ventilation. These factors allow early hospital discharge and timely multidisciplinary intervention, which is crucial for patients' quality of life and outcome optimisation.

Tracheostomy decannulation to noninvasive positive pressure ventilation in congenital central hypoventilation syndrome

PURPOSE

Noninvasive positive pressure ventilation (NPPV) may permit tracheostomy decannulation (TD) in patients with congenital central hypoventilation syndrome (CCHS) requiring nocturnal positive pressure ventilation via tracheostomy (PPV-T). There is limited evidence on optimal strategies for transitioning patients from PPV-T to NPPV. This study aimed to describe the clinical course and outcome of children with CCHS who underwent TD and transitioned from PPV-T to NPPV.

METHODS

Retrospective review was conducted on patients with CCHS using nocturnal PPV-T who underwent TD to NPPV. The results of clinical evaluations, airway endoscopy, polysomnography, and clinical course leading to TD were analyzed.

RESULTS

We identified 3 patients with CCHS aged 8-17 years who required PPV-T only during sleep. Patients underwent systematic multidisciplinary evaluations with a pediatric psychologist, pulmonologist, sleep physician, and otolaryngologist utilizing a TD algorithm. These included evaluation in the sleep clinic, NPPV mask fitting and desensitization, endoscopic airway evaluation, daytime tracheostomy capping, acclimatization to low-pressure NPPV, polysomnography with capped tracheostomy and NPPV titration, and if successful, TD. All patients underwent successful TD following optimal titration of NPPV during polysomnography. The duration to TD from decision to pursue NPPV was between 2.4 and 10.6 months, and the duration of hospitalization for TD was between 4 and 5 days. There were no NPPV-related complications; however, all patients required surgical closure of tracheocutaneous fistula.

CONCLUSION

NPPV may be an effective and feasible option for patients with CCHS requiring PPV-T during sleep and permits TD. In patients with CCHS, a systematic multidisciplinary algorithm may optimize successful transition to NPPV and TD.

How the Management of Children With Congenital Central Hypoventilation Syndrome Has Changed Over Time: Two Decades of Experience From an Italian Center

Background: Congenital central hypoventilation syndrome (CCHS) is a rare disorder whose clinical phenotype is closely related to genotype. Methods: A retrospective analysis has been conducted on 22 patients with CCHS, who were referred to the Pediatric Pulmonology and Respiratory Intermediate Care Unit of Bambino Gesù Children's Hospital (Italy) for a multidisciplinary follow-up program between 2000 and 2020. Results: Apnea and cyanosis were the most frequent symptoms at onset (91%). Overall, 59% of patients required tracheostomy and invasive mechanical ventilation (IMV) in the first months of life. Thirty-two percent of patients had Hirschsprung disease (HSCR) that was associated with longer polyalanine repetitions or non-polyalanine repeat expansion mutations (NPARMs). Polyalanine repeat expansion mutations (PARMs) were more frequent and two novel NPARMs (c.780dupT and C.225-256delCT) were described in 14% of patients. Focal epilepsy was first described in 14% of patients and neurocognitive and neuromotor impairment involved 27% and 23% of children, respectively. Symptoms due to autonomic nervous system dysfunction/dysregulation (ANSD)-including strabismus (27%), dysphagia (27%), abnormal heart rhythm (10%), breath-holding spells (9%), and recurrent seizures due to hypoglycemia (9%)-were associated with an increased number of polyalanine repetitions of exon 3 or NPARMs of PHOX2B gene. Overall, the number of patients with moderate to severe phenotype initially treated with non-invasive ventilation (NIV) increased over time, and the decannulation program was concluded with 3 patients who started with IMV. Conclusions: Our study confirms that more severe phenotypes of CCHS are related to the number of polyalanine repetitions or to NPARMs. Although invasive ventilation is often required by patients with severe genotype/phenotype, gradual acquisition of specific skills in the management of patients with CCHS and technological improvements in mechanical ventilation allowed us to improve our therapeutic approach in this population.

Guidelines for diagnosis and management of congenital central hypoventilation syndrome

BACKGROUND

Congenital Central Hypoventilation Syndrome (CCHS) is a rare condition characterized by an alveolar hypoventilation due to a deficient autonomic central control of ventilation and a global autonomic dysfunction. Paired-like homeobox 2B (PHOX2B) mutations are found in most of the patients with CCHS. In recent years, the condition has evolved from a life-threatening neonatal onset disorder to include broader and milder clinical presentations, affecting children, adults and families. Genes other than PHOX2B have been found responsible for CCHS in rare cases and there are as yet other unknown genes that may account for the disease. At present, management relies on lifelong ventilatory support and close follow up of dysautonomic progression. BODY: This paper provides a state-of-the-art comprehensive description of CCHS and of the components of diagnostic evaluation and multi-disciplinary management, as well as considerations for future research.

CONCLUSION

Awareness and knowledge of the diagnosis and management of this rare disease should be brought to a large health community including adult physicians and health carers.

Pediatric pulmonology year in review 2019: Sleep medicine

Pediatric Pulmonology publishes original research, review articles as well as case reports on a wide variety of pediatric respiratory disorders. In this article, we summarize the past year's publications in sleep medicine and we review selected literature from other journals within this field. Articles highlighted are topics on risk factors of sleep-disordered breathing, diagnosis, and treatment of obstructive sleep apnea as well as the utility of polysomnography in various complex conditions.

Evolution of Pediatric Home Mechanical Ventilation Program in Serbia-What Has Changed in the Last Decade

Home mechanical ventilation (HMV) is a method of treatment in children with sleep-disordered breathing (SDB) and alveolar hypoventilation regardless of primary disease. The goal of the study was to describe the changes in the HMV program in Serbia during the last two decades. Cross-sectional retrospective study included data from the national HMV database from 2001 until 2019. HMV was initiated in clinically stable patients after the failure to wean from mechanical ventilation succeeded acute respiratory deterioration or electively after the confirmation of SDB and alveolar hypoventilation by sleep study or continuous transcutaneous capnometry and oximetry. The study included 105 patients (50 ventilated noninvasively and 55 ventilated invasively via tracheostomy). The median age at the time of HMV initiation was 6.2 years (range: 0.3-18 years). Invasive ventilation had been initiated significantly earlier than noninvasive ventilation (NIV) (p < 0.01), without difference in duration of ventilatory support (p = 0.95). Patients on NIV were significantly older (p < 0.01) than those ventilated invasively (13 and 1.5 years, respectively). Average waiting time on equipment had been shortened significantly-from 6.3 months until 2010 to 1 month at the end of the study (p < 0.01). Only 6.6% of patients had obstructive sleep apnea syndrome (OSAS) requiring HMV. During the study period, 24% patients died, mostly due to uncontrolled infection or progression of underlying disease. Availability and shortened waiting time for the equipment accompanied by advanced overall health care led to substantial improvements in the national HMV program. However, future improvements should be directed to systematic evaluation of SDB in patients with OSAS, early diagnosis of nocturnal hypoventilation, and subsequent timely initiation of chronic ventilation.

Long Term Non-invasive Ventilation in Children With Central Hypoventilation

Central hypoventilation (CH) is a quite rare disorder caused by some congenital or acquired conditions. It is featured by increased arterial concentration of serum carbon dioxide related to an impairment of respiratory drive. Patients affected by CH need to be treated by mechanical ventilation in order to achieve appropriate ventilation and oxygenation both in sleep and wakefulness. In fact, in severe form of Congenital Central Hypoventilation Syndrome (CCHS) hypercarbia can be present even during the day. Positive pressure ventilation via tracheostomy is the first therapeutic option in this clinical condition, especially in congenital forms. Non-Invasive ventilation is a an option that must be reserved for more stable clinical situations and that requires careful monitoring over time.