Ventilatory response to added dead space in infants exposed to second-hand smoke in pregnancy.

Maternal cigarette smoking in pregnancy can adversely affect infant respiratory control. In utero nicotine exposure has been shown to blunt the infant ventilatory response to hypercapnia, which could increase the risk of sudden infant death syndrome. The potential impact of maternal second-hand smoke exposure, however, has not yet been determined.

Respiratory function monitoring during early resuscitation and prediction of outcomes in prematurely born infants.

Objectives: Over the last decade, there has been increased use of end-tidal carbon dioxide (ETCO) and oxygen saturation (SpO) monitoring during resuscitation of prematurely born infants in the delivery suite. Our objectives were to test the hypotheses that low end-tidal carbon dioxide (ETCO) levels, low oxygen saturations (SpO) and high expiratory tidal volumes (VT) during the early stages of resuscitation would be associated with adverse outcomes in preterm infants.

Methods: Respiratory recordings made in the first 10 min of resuscitation in the delivery suite of 60 infants, median GA 27 (interquartile range 25-29) weeks were analysed.

Early origins of respiratory disease.

Chronic respiratory morbidity is unfortunately common in childhood, particularly in those born very prematurely or with congenital anomalies affecting pulmonary development and those with sickle cell disease. Our research group, therefore, has focused on the early origins of chronic respiratory disease. This has included assessing antenatal diagnostic techniques and potentially therapeutic interventions in infants with congenital diaphragmatic hernia.

Tidal volume monitoring during initial resuscitation of extremely prematurely born infants.

Background Airway obstruction can occur during facemask (FM) resuscitation of preterm infants at birth. Intubation bypasses any upper airway obstruction. Thus, it would be expected that the occurrence of low expiratory tidal volumes (VTes) would be less in infants resuscitated via an endotracheal tube (ETT) rather than via an FM.

Sustained inflations during delivery suite stabilisation in prematurely-born infants - A randomised trial.

Background: Sustained inflations at initial stabilisation in the delivery suite may reduce the need for intubation and result in a shorter duration of initial ventilation, but have not been compared to routine UK practice.

Aims: To compare the early efficacy of sustained inflation during stabilisation after delivery to UK practice.

Study Design: A randomised trial was performed of a fifteen second sustained inflation compared to five inflations lasting 2 to 3 s, each intervention could be repeated once if no chest rise was apparent.

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 (V) (V > 6 ml/kg) and/or low-end tidal carbon dioxide (ETCO) levels (ETCO levels < 4.5 kPa) as recorded by respiratory function monitoring or hyperoxia (oxygen saturation (SaO) > 95%) during resuscitation in the delivery suite.

Detection of exhaled carbon dioxide following intubation during resuscitation at delivery.

Objectives: End tidal carbon dioxide (ETCO) monitoring can facilitate identification of successful intubation. The aims of this study were to determine the time to detect ETCO following intubation during resuscitation of infants born prematurely and whether it differed according to maturity at birth or the Apgar scores (as a measure of the infant's condition after birth).

Design: Analysis of recordings of respiratory function monitoring.

Sustained inflations versus UK standard inflations during initial resuscitation of prematurely born infants in the delivery room: a study protocol for a randomised controlled trial.

Background: Many infants born at less than 34 weeks of gestational age will require resuscitation in the delivery suite. Yet, different resuscitation techniques are specified in different national guidelines, likely reflecting a limited evidence base. One difference is the length of mechanical inflation initially delivered to infants either via a facemask or endotracheal tube.

Inflation pressures and times during initial resuscitation in preterm infants.

Background: The optimal combination of inflation pressures and times to produce adequate expiratory tidal volumes during initial resuscitation in prematurely born infants has not been determined. The aim of this study was therefore to assess combinations of inflation pressures and times and the resulting expiratory tidal volume levels using a respiratory function monitor.

Methods: Sixty-four infants born before 34 weeks of gestation were studied.

Synchronized mechanical ventilation for respiratory support in newborn infants.

Background: During synchronised mechanical ventilation, positive airway pressure and spontaneous inspiration coincide. If synchronous ventilation is provoked, adequate gas exchange should be achieved at lower peak airway pressures, potentially reducing baro/volutrauma, air leak and bronchopulmonary dysplasia. Synchronous ventilation can potentially be achieved by manipulation of rate and inspiratory time during conventional ventilation and employment of patient-triggered ventilation.

Synchronized mechanical ventilation for respiratory support in newborn infants.

Background: During synchronised mechanical ventilation, positive airway pressure and spontaneous inspiration coincide. If synchronous ventilation is provoked, adequate gas exchange should be achieved at lower peak airway pressures, potentially reducing baro/volutrauma, air leak and bronchopulmonary dysplasia. Synchronous ventilation can potentially be achieved by manipulation of rate and inspiratory time during conventional ventilation and employment of patient-triggered ventilation.

The first breath during resuscitation of prematurely born infants.

Background: The first five initial inflation pressures and times during resuscitation of prematurely born infants are frequently lower than those recommended and rarely result in tidal volumes exceeding the anatomical dead space. Greater volumes were produced when the infant was provoked to inspire by an inflation (active inflation).

Aims: To assess factors associated with a shorter time to the first active inflation.

In vitro assessment of the effect of proportional assist ventilation on the work of breathing.

Unlabelled: During proportional assist ventilation, elastic and resistive unloading can be delivered to reduce the work of breathing (WOB). Our aim was to determine the effects of different levels of elastic and resistive unloading on the WOB in lung models designed to mimic certain neonatal respiratory disorders. Two dynamic lung models were used, one with a compliance of 0.

Proportional assist versus assist control ventilation in premature infants.

Unlabelled: During proportional assist ventilation (PAV), the applied pressure is servo-controlled based on continuous input from the infant's breathing. In addition, elastic and resistive unloading can be employed to compensate for the abnormalities in the infant's lung mechanics. The aim of this study was to test the hypothesis that in very prematurely born infants remaining ventilated beyond the first week, PAV compared to assist control ventilation (ACV) would be associated with superior oxygenation.

Prematurely born infants' response to resuscitation via an endotracheal tube or a face mask.

Background: Prematurely born infants may be resuscitated in the labour suite via a face mask or an endotracheal tube.

Aims: To assess prematurely born infants' initial responses to resuscitation delivered via an endotracheal tube or a face mask, to determine if the first five inflations via an endotracheal tube produced expired tidal volumes greater than 4.4ml/kg (twice the anatomical dead space) and whether the outcome of initial resuscitation via an endotracheal tube or via a face mask differed according to the first active inflation (the infant's inspiratory effort coinciding with an inflation).

Crossover study of proportional assist versus assist control ventilation.

Objective: To test the hypothesis that in very prematurely born infants remaining ventilated beyond the first week, proportional assist ventilation (PAV) compared with assist control ventilation (ACV) would be associated with reduced work of breathing, increased respiratory muscle strength and less ventilator-infant asynchrony which would be associated with improved oxygenation.

Design: Randomised crossover study.

Setting: Tertiary neonatal unit.

Evaluation of respiratory function monitoring at the resuscitation of prematurely born infants.

Unlabelled: Our aim was to determine whether neonatal trainees found respiratory function monitoring (RFM) helpful during the resuscitation of prematurely born infants, what decisions they made on the basis of RFM and whether those decisions were evidence based. Fifty one trainees completed an electronic questionnaire. Eighty-three percent found the tidal volume display useful, 59 % altered the inflation pressure based on the tidal volume: 52 % considered 5 ml/kg adequate; 33 % 4 ml/kg; 13 % 6 ml/kg; and 2 % 7 ml/kg, despite no evidence on which to decide was the optimum tidal volume.

Sleeping position and responses to a carbon dioxide challenge in convalescent prematurely born infants studied post-term.

Objectives: To test the hypothesis that the ventilatory response to a carbon dioxide (CO2) challenge would be lower in the prone compared to the supine position in prematurely born infants studied post-term. To determine whether there were postural-related differences in respiratory drive, respiratory muscle strength, thoracoabdominal synchrony and/or lung volume.

Design: Prospective cohort study.

Neuromuscular blockade and lung function during resuscitation of infants with congenital diaphragmatic hernia.

Background: There is no consensus or evidence as to whether a neuromuscular blocking agent should be used during the initial resuscitation of infants with congenital diaphragmatic hernia (CDH) in the labour ward.

Objective: To determine if administration of a neuromuscular blocking agent affected the lung function of infants with CDH during their initial resuscitation in the labour ward.

Methods: Fifteen infants with CDH were studied (median gestational age 38 weeks, range 34-41; birth weight 2,790 g, range 1,780-3,976).

Respiratory syncytial virus infection and chronic respiratory morbidity - is there a functional or genetic predisposition?

Unlabelled: A systematic literature review has been undertaken. Respiratory syncytial virus (RSV) lower respiratory tract infection (LRTI) in infancy is associated with chronic respiratory morbidity. Premorbid abnormal lung function may predispose to RVS LRTI in prematurely born infants.

End tidal carbon dioxide levels during the resuscitation of prematurely born infants.

Background: Successful resuscitation of prematurely born infants is dependent on achieving adequate alveolar ventilation and vasodilation of the pulmonary vascular bed. Elevation of end-tidal carbon dioxide (ETCO(2)) levels may indicate pulmonary vasodilation.

Aims: This research aims to study the temporal changes in ETCO(2) levels and the infant's respiratory efforts during face mask resuscitation in the labour suite, and to determine if the infant's first inspiratory effort was associated with a rise in the ETCO(2) levels, suggesting pulmonary vasodilation had occurred.

Lung function at follow-up of infants with surgically correctable anomalies.

Infants with congenital diaphragmatic hernia (CDH) or anterior wall defects (AWD) can suffer abnormal antenatal lung growth, the risk, however, may be greater for CDH infants. The objectives of this study were to test the hypothesis that following surgical correction, CDH infants would have worse lung function at follow-up than AWD infants and to determine whether fetal lung volume (FLV) results correlated with the lung function results at follow-up. Thirteen infants with CDH and 13 infants with AWD had lung function measurements at a median age of 11 (range 6-24) months; 17 of the infants had had their FLV assessed.

Inflation times during resuscitation of preterm infants.

Unlabelled: Data on the effects of a prolonged inflation time during the resuscitation of very prematurely born infants are limited; one study showed no effect, and in another, although lower bronchopulmonary dysplasia (BPD) rates were seen, that effect could have been due to the prolonged inflation time, the positive end expiratory pressure applied or the combination of the two. The aims of our study were to assess the length of inflation times used during face mask and t-piece resuscitation of prematurely born infants in the labour suite and determine whether prolonged inflations led to longer inflation flow times. A respiration monitor (NM3 respiratory profile monitor) was used to record flow, airway pressure and tidal volume changes.

Volume-targeted ventilation in infants born at or near term.

Objectives: To determine the impact of different volume-targeted (VT) levels during volume-targeted ventilation (VTV) on the work of breathing (WOB) of infants born at or near term and to investigate whether a level of VT reduced the WOB below that experienced on respiratory support without VT.

Design: Prospective crossover study.

Patients: Sixteen infants, median gestational age of 38 (range 34-41) weeks, birth weight of 3.