PERINATAL/NEONATAL CASE PRESENTATION Monitoring diaphragm electrical activity and the detection of congenital central hypoventilation syndrome in a newborn T Szczapa 1 , J Beck 2 , M Migdal 3 and J Gadzinowski 1 A full-term newborn infant is described with recurrent episodes of oxygen desaturation and apnea on the day of birth. The apnea did not improve with continuous positive airway pressure (CPAP) and intermittent nasal ventilation, therefore intubation and mechanical ventilation were required. A preliminary diagnosis of congenital central hypoventilation syndrome (CCHS) was made with the use of simultaneous measurements of end-tidal CO 2 (EtCO 2 ) and a diaphragm electrical activity waveform that was detected using microsensors placed on the infant’s feeding tube. It was observed that during deep sleep, the diaphragm electrical activity waveform was close to 0 mV (central apnea) and EtCO 2 levels rose accordingly (central hypoventilation). Genetic testing subsequently revealed a Phox2b mutation, establishing the diagnosis of CCHS. Simultaneously measuring diaphragm electrical activity and EtCO 2 is feasible and may be a valuable bedside diagnostic tool in cases of suspected CCHS before the diagnosis is confirmed with genetic testing. Journal of Perinatology (2013) 33, 905–907; doi:10.1038/jp.2013.89 Keywords: congenital central hypoventilation syndrome; newborn; diaphragm electrical activity; central apnea; mechanical ventilation; Phox2b mutation INTRODUCTION Congenital central hypoventilation syndrome (CCHS) is a rare disorder defined by impaired automatic control of breathing. Patients typically present with alveolar hypoventilation primarily while asleep. 1 Sensitivity to hypercapnia and hypoxia is decreased, and ventilatory support is required in affected individuals. First symptoms are usually observed in the neonatal period. The paired-like homeobox 2B gene (Phox2b) was found to be the disease-defining gene for CCHS. 1 Today, the control of breathing can be routinely and clinically monitored in infants requiring mechanical ventilation, via measurements of the diaphragm electrical activity (EAdi). 2,3 Miniaturized microsensors mounted on a naso/orogastric feeding tube detect the spontaneous breathing activity, and impose no additional invasiveness to infants being fed enterally while on mechanical ventilation. The EAdi waveform provides information about the neural respiratory effort, 2 and in its absence, it is an indicator of central apnea. CASE A 4560-g female baby was born at 38 weeks of gestation by Cesarean section. The course of pregnancy was uneventful, but the decision regarding the mode of delivery was taken because of postnatal complications in a prior sibling who has cerebral palsy of unclear origin. The newborn in this case report was breathing spontaneously after birth, but presented with apnea in the third minute of life. Cord blood gases were normal (pH ¼ 7.37, base excess ¼ –0.3). Because of recurrent episodes of desaturation and apnea associated with respiratory acidosis and hypercapnia (with PaCO 2 reaching 90 mm Hg), the infant was treated with non- invasive ventilatory support (Infant Flow SiPAP, Carefusion, Yorba Linda, CA, USA). Nasal continuous positive airway pressure (CPAP) and intermittent nasal ventilation was insufficient to maintain a normal clinical- and pulmonary laboratory state. Hence, the baby required intubation and mechanical ventilation with synchronized intermittent mandatory ventilation (SIMV) combined with pressure support (PS) mode (Servo-I ventilator, Maquet, Solna, Sweden). At 19 days after birth, the infant was extubated but required non-invasive respiratory support (BiPhasic mode of the Infant Flow SiPAP device) while asleep for reoccurring apnea. From birth, apneic episodes were observed whenever the baby went to sleep. While awake, the baby was breathing regularly without any clinical signs of increased work of breathing. No metabolic disorders were diagnosed in this patient. Cerebral anomalies and congenital heart defects were ruled out by ultrasound studies. The baby revealed no pathological findings on ophthalmic and neurological exam- inations. Electroencephalography recording was normal. The older sister of this patient suffers from cerebral palsy. The child requires home mechanical ventilation using a tracheostomy, because apnea always occurs when she goes to sleep, a clinical characteristic shared by this index case. Based on these findings in the patient and the older sibling, a disorder involving the central regulation of breathing was suspected. In order to assess the neural respiratory drive and respiratory control, the electrical activity of the diaphragm (EAdi) was measured. This was achieved by a commercially available sensor placed in the esophagus (NAVA catheter, Maquet Critical Care) at the level of the gastro-esophageal junction (Figure 1). 4 The sensor also has the capability of feeding, similar to a standard naso- gastric feeding tube, and therefore, imposes no additional invasiveness. End-tidal CO 2 (EtCO 2 ) was simultaneously measured (CO 2 Analyzer Module, Maquet Critical Care). During 1 Department of Neonatology, Poznan University of Medical Sciences, Poznan, Poland; 2 Keenan Research Centre, Li Ka Shing Knowledge Institute, St Michael’s Hospital, Toronto, Ontario, Canada and 3 Pediatric Intensive Care Unit, Children’s Memorial Health Institute, Warsaw, Poland. Correspondence: Dr T Szczapa, Department of Neonatology, Poznan University of Medical Sciences, ul. Polna 33, Poznan 60-535, Poland. E-mail: tszczapa@ump.edu.pl Received 13 May 2013; accepted 19 June 2013 Journal of Perinatology (2013) 33, 905–907 & 2013 Nature America, Inc. 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