Ravindra Bhat

Assessment of diaphragm function in lumbocostovertebral syndrome

Diaphragm function testing can play a key role in determining the management of respiratory problems of infants with multiple anomalies. The diaphragm is the main respiratory muscle in infancy, thus diaphragmatic maldevelopment may cause respiratory embarrassment. Diagnosis and treatment, however, can be hindered by the lack of appropriate quantitative assessments of neonatal diaphragm function. We report the use of magnetic stimulation of the phrenic nerves to facilitate management of the persisting supplementary oxygen requirement of an infant with lumbocostovertebral syndrome. A male infant, birth weight 3.04 kg, was born at term to non-consanguineous parents. The mother had mild gestational diabetes mellitus. Antenatal ultrasound examination revealed a thoracolumbar meningocoele, an Arnold Chiari malformation and a right talipes. The infant also had a scoliosis, due to hemivertebrae between T8 and L3, a small right hemithorax with absent ribs (8 to 12) and a large lumbar hernia (Fig. 1). The infant was dependent on supplementary oxygen from birth, which persisted after the meningocoele was closed. MRI and ultrasound examination excluded a diaphragmatic hernia, but not an eventration. It was unclear, therefore, whether the supplementary oxygen requirement was due solely to the probable right lung hypoplasia or diaphragmatic malfunction was a contributory factor and the infant would benefit from a plication. Respiratory and diaphragmatic function testing was undertaken. Lung volume measurement revealed a functional residual capacity of 20 ml/kg (reference range 24–36 ml/kg), that is the infant had moderate lung hypoplasia. Diaphragm function was assessed by measurement of the maximal inspiratory pressure (MIP) and the transdiaphragmatic pressure generated by magnetic stimulation of the right and left phrenic nerves [5]. The MIP was 60 cmH2O (reference range 42–105 cmH2O) [2] and phrenic nerve stimulation revealed similar right and left transdiaphragmatic pressures (left 3.8 cmH2O; right 3.8 cmH2O). As a consequence, surgical plication of the right hemidiaphragm was deemed unnecessary. The infant was discharged home at 2 months of age still oxygen dependent. The lumbocostovertebral syndrome is rare [1] and includes hemivertebra, absent ribs, meningomyelocoele Fig. 1 Chest and abdominal radiograph taken to identify the position of the umbilical artery catheter. Note hemivertebrae, rightsided lumbar hernia and abnormal rib configuration

Investigation and management of gastro-oesophageal reflux in United Kingdom neonatal intensive care units

In 2004, wide variation in the investigation and management of gastro‐oesophageal reflux (GOR) of infants on UK major neonatal units was demonstrated. Our aim was to resurvey neonatal practitioners to determine current practice and whether it was now evidence based.

Detection of gastro-oesophageal reflux in the neonatal unit

To determine whether a pH probe or multichannel intraluminal impedance (MII) more frequently detected gastro‐oesophageal reflux and test the hypothesis that acid reflux was associated with lower baseline impedance.

Antenatal smoking and substance-misuse, infant and newborn response to hypoxia.

To determine at the peak age for sudden infant death syndrome (SIDS) the ventilatory response to hypoxia of infants whose mothers substance misused in pregnancy (SM infants), or smoked during pregnancy (S mothers) and controls whose mothers neither substance misused or smoked. In addition, we compared the ventilatory response to hypoxia during the neonatal period and peak age of SIDS.

The effects of sleeping position, maternal smoking and substance misuse on the ventilatory response to hypoxia in the newborn period

BackgroundMaternal smoking, substance misuse in pregnancy and prone sleeping increase the risk of sudden infant death syndrome (SIDS). We examined the effect of maternal smoking, substance misuse and sleeping position on the newborn response to hypoxia.MethodsInfants born between 36 and 42 weeks of gestational age underwent respiratory monitoring in the prone and supine sleeping position before and during a hypoxic challenge. Minute ventilation (MV) and end-tidal carbon dioxide (ETCO2) levels were assessed.ResultsSixty-three infants were studied: 22 controls, 23 whose mothers smoked and 18 whose mothers substance-misused and smoked. In the supine position, baseline MV was higher and ETCO2 levels were lower in infants of substance-misusing mothers compared to controls (pu2009=u20090.015, pu2009=u20090.017, respectively). Infants of substance-misusing mothers had a lower baseline MV and higher ETCO2 levels in the prone position (pu2009=u20090.005, pu2009=u20090.004, respectively). When prone, the rate of decline in minute ventilation in response to hypoxia was greater in infants whose mothers substance-misused and smoked compared to controls (pu2009=u20090.002) and infants of smoking mothers (pu2009=u20090.016).ConclusionThe altered response to hypoxia in the prone position of infants whose mothers substance-misused and smoked in pregnancy may explain their increased vulnerability to SIDS.

Relationship of resuscitation, respiratory function monitoring data and outcomes in preterm infants

Intraventricular haemorrhage (IVH) and bronchopulmonary dysplasia (BPD) are major complications of premature birth. We tested the hypotheses that prematurely born infants who developed an IVH or BPD would have high expiratory tidal volumes (VTE) (VTEu2009>u20096xa0ml/kg) and/or low-end tidal carbon dioxide (ETCO2) levels (ETCO2 levels <u20094.5xa0kPa) as recorded by respiratory function monitoring or hyperoxia (oxygen saturation (SaO2)u2009>u200995%) during resuscitation in the delivery suite. Seventy infants, median gestational age 27xa0weeks (range 23–33), were assessed; 31 developed an IVH and 43 developed BPD. Analysis was undertaken of 31,548 inflations. The duration of resuscitation did not differ significantly between the groups. Those who developed an IVH compared to those who did not had a greater number of inflations with a high VTE and a low ETCO2, which remained significant after correcting for differences in gestational age and birth weight between groups (pu2009=u20090.019). Differences between infants who did and did not develop BPD were not significant after correcting for differences in gestational age and birth weight. There were no significant differences in the duration of hyperoxia between the groups.Conclusions: Avoidance of high tidal volumes and hypocarbia in the delivery suite might reduce IVH development.What is known• Hypocarbia on the neonatal unit is associated with the development of intraventricular haemorrhage (IVH) and bronchopulmonary dysplasia (BPD).What is new• Infants who developed an IVH compared to those who did not had significantly more inflations with high expiratory tidal volumes and low ETCO2s.

Neonatal Physiology and Care

Return of oxgenated blood from the placenta, via umbilical vein, left portal vein, and ductus venosus to the right atrium (80%, with remaining 20% going through liver sinusoids). Mixing with de-oxygenated blood from SVC, which tends to be streamed to right ventricle and pulmonary artery. Two natural shunt mechanisms avoid futile pulmonary circulation.