Characteristics and outcomes in children with congenital central hypoventilation syndrome on long-term mechanical ventilation in the Netherlands

Congenital central hypoventilation syndrome (CCHS) is a rare condition characterized by central hypoventilation, leading to the majority of patients being dependent on ventilatory support during sleep. This condition is often accompanied by various associated symptoms, due to a PHOX2B gene variant involved in neuronal crest cell migration. This study is the first to review the characteristics and outcomes in children with CCHS on long-term mechanical ventilation in the Netherlands. We performed a retrospective study of all CCHS patients treated in the 4 Centers of Home Mechanical Ventilation of the University Medical Centers in the Netherlands from 2000 till 2022 by collecting information from the electronic medical records, documented during follow-up. We included 31 patients, out of which 27 exhibited a known genetic profile associated with CCHS, while no PHOX2B variant was identified in the remaining patients. Among the 27 patients with known genetic profiles, 10 patients had a non-polyalanine repeat expansion mutation (NPARM), followed by 20/27, 20/25, and 20/26 polyalanine repeat expansion mutations (PARMs) in descending order. The most common presentation involved respiratory failure or apneas during the neonatal period with an inability to wean off ventilation. The majority of patients required ventilatory support during sleep, with four patients experiencing life-threatening events related to this dependency. Daily use of ventilatory support varied among different genetic profiles. All genotypes reported comorbidities, with Hirschsprung's disease and cardiac arrhythmias being the most reported comorbidities. Notably, Hirschprung's disease was exclusively observed in patients with a 20/27 PHOX2B variant.

CONCLUSION

Our study results suggest that in our cohort, the genotype is not easily associated to the phenotype in CCHS. Consistent with these findings and international literature, we recommend a thorough annual evaluation for all patients with CCHS to ensure optimal management and follow-up.

WHAT IS KNOWN

• The majority of CCHS patients are dependent on ventilatory support. • Variants in the PHOX2B gene are responsible for the characteristics of CCHS.

WHAT IS NEW

• This study provides insight into the clinical course and long-term outcomes of CCHS patients in the Netherlands. • In CCHS, the genotype is not easily associated with the phenotype, requiring a thorough life-long follow-up for all patients.

Walking with continuous positive airway pressure

A ventilator-dependent child had been in the paediatric intensive care unit (PICU) ever since birth. As a result, she had fallen behind considerably in her development. After 18 months, continuous positive airway pressure was successfully administered via a tracheostomy tube with a novel lightweight device. This enabled her to walk in the PICU. With this device, the child was discharged home where she could walk with an action range of 10 m. Subsequently, her psychomotor development improved remarkably. To the authors' knowledge, this is the first case report of a patient, adult or paediatric, who could actually walk with a sufficient radius of action while receiving long-term respiratory support.

[Active management of children after ingestion of a button battery]

Four children, three girls in the age range up to 14 months and a boy aged 10 years, were admitted because of button battery ingestion. In two patients, the course was uncomplicated, with spontaneous passage of the batteries. Two other patients, a girl aged 11 months and a girl aged 6 weeks, developed severe complications: stenosis of the oesophagus in one patient and a dramatic clinical course with a tracheo-oesophageal fistula and oesophageal damage in the other. Ingestion of foreign bodies in children is a common problem. With the increased use of miniature electronic devices, the incidence of button battery ingestion is rising. Ingestion of a battery is an indication for urgent referral and radiological examination. Electrochemical tissue damage and impaction may lead to serious complications within hours. If the battery is located in the oesophagus, endoscopic removal should be attempted as soon as possible. A conservative approach can be followed when the battery is located in the stomach or beyond, and complaints are absent.

Dexamethasone for treatment of patients mechanically ventilated for lower respiratory tract infection caused by respiratory syncytial virus

BACKGROUND

A study was undertaken to evaluate the efficacy of dexamethasone in patients mechanically ventilated for lower respiratory infection caused by respiratory syncytial virus (RSV-LRTI).

METHODS

In a multicentre randomised controlled trial patients were randomised to receive either intravenous dexamethasone (0.15 mg/kg 6 hourly for 48 hours) or placebo. End points were the duration of mechanical ventilation, length of stay (LOS) in the pediatric intensive care unit (PICU) and in hospital, and the duration of supplemental oxygen administration.

RESULTS

Thirty seven patients received dexamethasone and 45 received placebo. There was no significant difference in any of the end points between the two groups. In a post hoc analysis patients were stratified into those with mild gas exchange anomalies (PaO(2)/FiO(2) >200 mm Hg and/or mean airway pressure </= 10 cm H(2)O, bronchiolitis group) and those with severe gas exchange anomalies (PaO(2)/FiO(2) </=200 mm Hg and mean airway pressure >10 cm H(2)O, pneumonia group). In the 39 patients with bronchiolitis the duration of mechanical ventilation was 4.3 days shorter in the dexamethasone group than in the placebo group (4.9 v 9.2 days, 95% CI -7.8 to -0.8, p=0.02) and the duration of supplemental oxygen was 3.6 days shorter (7.7 v 11.3 days, 95% CI -8.0 to -0.1, p=0.048). No differences in end points were found in the pneumonia group.

CONCLUSIONS

Dexamethasone had no beneficial effect in patients mechanically ventilated for RSV-LRTI but was found to have a beneficial effect in patients with bronchiolitis.

[Clinical thinking and decision-making in practice. A child with dyspnea and excess pleural fluid]

Pleural fluid was diagnosed on an X-ray in a 9-month-old boy with acute dyspnoea without fever. Thoracentesis showed exudate and the patient was diagnosed as having empyema and was treated with continuous chest tube drainage and antibiotics. The culture of the pleural fluid was negative. A month after discharge the boy developed recurrent pleural effusion with dyspnoea. A mass in the right hemithorax was found upon additional diagnostic evaluation. Microscopic evaluation of tumour biopsy specimen showed a malignancy. Infantile fibromatosis was diagnosed in a surgical specimen. The patient died after having developed a recurrent tumour. Infectious causes are not likely in a child with pleural fluid without fever. Pleural fluid has to be analysed in transudate or exudate. Exudate requires a complete diagnostic evaluation.

[Bilirubin encephalopathy in an icteric bile-vomiting infant with high intestinal obstruction]

In a 5-day-old full-term, dehydrated boy with bilious vomiting and a cephalhaematoma, bilirubin encephalopathy was diagnosed at a serum bilirubin level of 395 mumol/l. The patient was rehydrated intravenously and treated with phototherapy and an exchange transfusion, after which the serum bilirubin level decreased. The neurological condition normalised during his stay in the hospital. Hyperbilirubinaemia was caused by an increased enterohepatic circulation due to a high intestinal obstruction and resorption of the cephalhaematoma. Toxicity was caused by dehydration and fasting. Even with new bilirubin guidelines it remains important to distinguish a healthy neonate from an ill jaundiced neonate, because at lower serum bilirubin levels symptoms may occur that fit the clinical picture of a bilirubin encephalopathy.

Spinal osteomyelitis caused by Proteus mirabilis in a child

Osteomyelitis due to Proteus mirabilis is rare. Spinal osteomyelitis caused by this organism has only been described in adults. This is the first paediatric case of P. mirabilis vertebral osteomyelitis.