Prolonged neuromuscular block associated with cholinesterase deficiency.

RATIONALE: Hereditary genetic mutations may cause congenital cholinesterase deficiency. When succinylcholine and mivacurium are applied on cholinesterase-deficient patients during general anesthesia, prolonged postoperative asphyxia occurs, which is an uncommon but very serious complication. PATIENT CONCERNS: A previously healthy 30-year-old female presented prolonged spontaneous breathing recovery after general anesthesia. DIAGNOSES: After the patient's postoperative spontaneous breathing recovery delayed, the plasma cholinesterase was found to be 27 U/L, which was far below the normal level (4000 U/L to 13500 U/L). This patient had no disease that can cause plasma cholinesterase deficiency and was therefore diagnosed as congenital cholinesterase deficiency. INTERVENTIONS AND OUTCOMES: The patient was sent to the intensive care unit (ICU) intubated for mechanical ventilator support, and on the next day the tracheal tube was removed without any complications when her spontaneous respiration resumed. LESSONS: Cholinesterase is an enzyme secreted by the liver involved in many physiological processes in human body. Plasma cholinesterase commonly contains acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). When succinylcholine and mivacurium are applied on patients with cholinesterase-deficiency during general anesthesia, prolonged postoperative asphyxia occurs, which is an uncommon but very serious complication. Lately, new evidences have suggested that hereditary genetic mutations may be responsible for congenital cholinesterase deficiency.

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.

Brainstem tegmental necrosis and olivary hypoplasia: raising awareness of a rare neuropathologic correlate of congenital apnea.

This case study describes an instance of death in an early term female newborn with congenital apnea in the clinical setting of multiple congenital anomalies (retrognathia, posteriorly rotated ears, camptodactyly, and arthrogryposis) and prenatal history of polyhydramnios. Postmortem neuropathologic findings were significant for tegmental necrosis in the caudal pons and medulla characterized by a coalescence of microcalcifications accompanied by neuronal loss, axonal spheroids, gliosis, and a concomitant hypoplasia of the inferior olives. This report raises awareness of the rare lethal entity of brainstem tegmental necrosis and olivary hypoplasia and its nosological relationship to the Möbius syndrome in the context of differential diagnosis of congenital apnea owing to central respiratory dysfunction.

Safety profile comparison between extemporaneous and a licensed preparation of caffeine citrate in preterm infants with apnea of prematurity.

BACKGROUND: Given the lack of a licensed product (LP), extemporaneous caffeine citrate (ECC) has been used by many hospital pharmacies. OBJECTIVES: Since July 2011, an LP has been available in Germany. We prospectively compared the safety profile of ECC and LP in preterm infants with apnea of prematurity. METHODS: Between April 2010 and April 2013, selected side effects occurring with ECC or LP were documented in 6 German NICUs for infants ≤34 weeks' gestation using a longitudinal study design. The software developed for daily prescriptions in NICU residents requires entries if any of the following symptoms occurred during the last 24 h: tachycardia (resting heart rate >200/min), clinical or encephalographic seizures, gastric residuals, vomiting, or necrotizing enterocolitis (NEC). ECC and LP were administered at identical doses (20 mg/kg/day loading, 5-10 mg/kg/day maintenance) and in similar formulations either orally or intravenously. RESULTS: 562 infants with 14,590 treatment days on ECC and 538 infants with 12,813 treatment days on LP were evaluated. The mean gestational age was similar (29.20 weeks for ECC vs. 29.14 weeks for LP). No relevant differences were seen concerning tachycardia, gastric residuals, or vomiting, but ECC was associated with a higher risk of NEC (risk ratio: 2.68, 95% CI: 1.01-7.23, p = 0.047) and, albeit not significantly so, seizures (risk ratio: 1.91, 95% CI: 0.53-6.96, p = 0.35). CONCLUSION: This survey demonstrates a similar safety profile for both forms of caffeine citrate. The lower NEC and seizure rate seen with the LP is intriguing, but requires confirmation in a controlled study design.

Automatic detection of apnoea of prematurity.

The detection of the incidents of apnoea of prematurity (AP) in preterm infants is important in the intensive care unit, but this detection is often based on simple threshold techniques, which suffer from poor specificity. Three methods for the automatic detection of AP were designed, tested and evaluated using approximately 2426 h of continuous recording from 54 neonates (µ = 44 h and σ = 7 h). The first method was based on the cumulative sum of the time series of heart rate (HR), respiratory rate (RR) and oxygen saturation (SpO(2)) along with the sum of their Shannon entropy. The performance of this method gave 94.53% sensitivity, 74.72% specificity and 77.84% accuracy. The second method was based on the correlation between the time series of HR, RR and SpO(2), which were used as inputs to an artificial neural network. This gave 81.85% sensitivity, 75.83% specificity and 76.78% accuracy. The third method utilized the derivative of the three time series and yielded a performance of 100% sensitivity, 96.19% specificity and 96.79% accuracy. Although not optimized to work in real time, the latter method has the potential for forming the basis of a real time system for the detection of incidents of AP.

Apnea and macrocephaly-cutis marmorata telangiectatica congenita.

The authors report a case of an infant girl with macrocephaly-cutis marmorata telangiectatica congenita (Macrocephaly-CMTC). This patient presented with developmental delay, mild subcostal retractions, and occasional apneic spells. An MRI demonstrated mild to moderate lateral ventricle hydrocephalus, left hemi-megalencephaly, and left cerebellar tonsillar herniation with full occlusion of the cisterna magna. Her foramen magnum was narrowed, measuring 17.5mm in transverse diameter. This value was significantly below the 50th percentile for age, which is 23.5mm. Together, these findings were suggestive of cervicomedullary cord compression, concerning for sudden death. The patient underwent posterior fossa decompression by suboccipital craniectomy and cervical laminectomy. Initially due to hypertrophy and paralysis of the left true and false vocal cords, endotracheal intubation was not achieved, requiring tracheostomy tube placement. To our knowledge this is the first report of apnea in a patient diagnosed with M-CMTC, likely due to cervicomedullary cord compression and perhaps exacerbated by unilateral laryngeal hypertrophy. M-CMTC is a newly-described hemi-hypertrophy syndrome affecting the neurodevelopment of affected children. The authors emphasize airway obstruction secondary to unilateral hypertrophy of the vocal cords in addition to brainstem compromise as a consideration for the etiology of apnea in M-CMTC patients presenting with signs and symptoms of cervicomedullary cord compression.

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.

Brainstem tegmental necrosis and olivary hypoplasia: a lethal entity associated with congenital apnea.

Previously, we reported an isolated case of a newborn with central apnea at birth, ventilator-dependence, and combined malformative and destructive brainstem lesions (1). We now report 2 additional cases with similar clinicopathologic features. All 3 patients were male (XY karyotype) and required immediate ventilatory support in the delivery room. Perinatal complications included polyhydramnios and breech presentation. Variable cranial nerve palsies and orofacial and limb anomalies were present. The patients dies within minutes of withdrawal of ventilatory support at 2 to 11 weeks after birth. Significant neuropathologic findings were localized to the caudal pons and medulla, and included tegmental necrosis (neuronal loss, gliosis, mineralization) with involvement of respiratory-related nuclei, and anomalies of rhombic lip derivatives (olivary hypoplasia, arcuate nucleus hyperplasia). Three-dimensional computer reconstructions facilitated clinicoanatomic correlations, and underscored the restriction of the lesions to pontine and medullary rhombomeres and rhombic lip. The histopathology of these cases suggests a malformative process occurring at the end of the first trimester (time of rhombic lip migrations), and a superimposed destructive process (tegmental necrosis) in the second half of gestation. Although the etiology is unknown, the segmental nature of the lesions suggests the possibility of an abnormality in homeobox gene regulation. These cases likely represent a distinct clinicopathologic entity that should be considered in the differential diagnosis of Moebius syndrome and failure to breathe at birth.

Congenital apnea with medullary and olivary hypoplasia: a pathologic study with computer reconstructions.

We report a three-month-old infant with congenital central apnea who was ventilator-dependent throughout his brief life. At autopsy the most significant findings were localized to the medulla and included severe tegmental necrosis involving respiratory-related sites and olivary hypoplasia. Golgi impregnations of the cerebellum demonstrated several Purkinje cells with changes consistent with experimental olivary ablation. The majority of Purkinje cells, however, were normal; this observation suggests that in an early and subtotal olivary lesion, the incomplete complement of olivary neurons maintains sufficient collateral axonal branches to compensate for decreased cell number. Computer graphics enabled us to dissect the components of the complex medullary pathology and examine them individually and in selected combinations in three dimensions. Computer reconstruction aided the identification and dating of a malformative lesion (first trimester) from a later (second/third trimester), superimposed destructive lesion. This report suggests that the synthesis of complex morphologic data in human neuropathology into meaningful three-dimensional visual displays by computer reconstruction facilitates their comprehension. Computer reconstruction is especially valuable in the elucidation of 3-D topographic relationships in functionally and architecturally complex regions such as the brain stem.

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.