A prospective observational cohort study of exposure to womb-like sounds to stabilize breathing and cardiovascular patterns in preterm neonates.

PURPOSE: We exposed premature infants to womb-like sounds to evaluate such exposure on breathing and cardiovascular patterns. We hypothesized that these sounds would reduce apnea and intermittent hypoxemia, enhance parasympathetic outflow, and improve cardiovascular patterns. METHODS: A total of 20 cases and 5 control infants at ≤32-36 weeks corrected gestational age participated in a prospective observational cohort study. Twenty-four hours of continuous ECG, respiratory and oxygen saturation data were collected in all infants. Womb-like sounds were played intermittently in 6-hour blocks. Salivary samples were collected at study beginning and end for cortisol. Apnea, intermittent hypoxemia, and bradycardia were evaluated, and heart rate variability was assessed by time domain and spectral techniques. RESULTS: Intermittent hypoxemia and bradycardia significantly declined after sound exposure. No significant differences in apnea, cortisol levels, or heart rate variability were evident among the study infants. CONCLUSIONS: Exposing premature infants to womb-like sounds has the potential to reduce hypoxemic and bradycardic events, and be used as an intervention to stabilize breathing and cardiac control in preterm infants.

Incidental diagnosis of an H-type tracheo-oesophageal fistula.

A 6-day-old term neonate who was intubated on day 1 of life for apnoeic episodes, was transferred to the regional paediatric intensive care unit (PICU) for specialist opinion following 3 failed extubations in the neonatal unit. Escherichia coli congenital pneumonia was diagnosed and the child discharged to the local hospital. Chest radiographs and inflammatory markers were in keeping with infection. However, ongoing difficulties with secretions necessitated readmission to the PICU, following a significant cyanotic episode associated with coughing. On arrival at the PICU, a large leak around the endotracheal tube (ETT) was noted. On direct laryngoscopy, the ETT was found correctly positioned, through the cords, but air was noted to be coming back from the oesophagus. Advancing the ETT towards the carina terminated the leak and raised the suspicion of a tracheo-oesophageal fistula. An H-type tracheo-oesophageal fistula was confirmed on bronchoscopy. An uneventful fistula repair was performed and the baby discharged from the PICU on day 23 of life.

A lethal association of congenital apnea with brainstem tegmental necrosis.

We present a female with premature birth, polyhydramnios, congenital apnea, cranial nerve palsies, orofacial and limb anomalies. Neuroimaging revealed calcifications along the vental margin of the caudal fourth ventricle. Neuropathologic findings at postmortem examination were consistent with brainstem tegmental necrosis and olivary hypoplasia, a rare lethal entity that should be considered in the differential diagnosis of congenital apnea.

Rnx deficiency results in congenital central hypoventilation.

The genes Tlx1 (Hox11), Enx (Hox11L2, Tlx-2) and Rnx (Hox11L2, Tlx-3) constitute a family of orphan homeobox genes. In situ hybridization has revealed considerable overlap in their expression within the nervous system, but Rnx is singularly expressed in the developing dorsal and ventral region of the medulla oblongata. Tlx1-deficient and Enx-deficient mice display phenotypes in tissues where the mutated gene is singularly expressed, resulting in asplenogenesis and hyperganglionic megacolon, respectively. To determine the developmental role of Rnx, we disrupted the locus in mouse embryonic stem (ES) cells. Rnx deficient mice developed to term, but all died within 24 hours after birth from a central respiratory failure. The electromyographic activity of intercostal muscles coupled with the C4 ventral root activity assessed in a medulla-spinal cord preparation revealed a high respiratory rate with short inspiratory duration and frequent apnea. Furthermore, a coordinate pattern existed between the abnormal activity of inspiratory neurons in the ventrolateral medulla and C4 motorneuron output, indicating a central respiratory defect in Rnx mice. Thus, Rnx is critical for the development of the ventral medullary respiratory centre and its deficiency results in a syndrome resembling congenital central hypoventilation.

Medullary nuclear dysplasia (Möbius syndrome) in an infant with recurrent apnea and isoelectric EEG.

From birth, an infant girl had repeated episodes of loss of consciousness, apnea and bradycardia, aphonia, and severe pharyngeal-esophageal discoordination. These functional deficits correlated with a gross and microscopic malformation of the medulla oblongata, which is characterized by profound deficits of motor and sensory nuclei and of the reticular formation. We have classified this as an example of Möbius syndrome. No etiology was suggested from the history. Histopathologic findings are compatible with an early massive insult to developing structures in the tegmentum of the medulla oblongata.