Definitive analysis of solute concentrations in lung lavage fluid involves the use of a marker of... more Definitive analysis of solute concentrations in lung lavage fluid involves the use of a marker of dilution to correct for variable recovery of epithelial lining fluid (ELF), but the question of the most appropriate dilutional marker remains unresolved. In lavage fluid collected from infants with lung disease and healthy control subjects, we examined ELF concentration of protein, albumin, sphingomyelin (SM), and IgA secretory component (SC), and critically appraised the relative validity of SC and urea as dilutional markers in the context of lung infection and lung injury. Protein, albumin, and SM were found not to be valid dilutional markers, as their ELF concentration varied significantly between the diseased, recovering, and normal lung. Differences in concentration were noted in both tracheal aspirate samples (TA, 4 x 0.5 ml) and nonbronchoscopic bronchoalveolar lavage fluid (NB-BAL, 3 x 1 ml/kg), but were not uniform (e.g., TA-disease versus control: albumin 2.8 versus 0.68 mg/ml, SM 45 versus 16 microgram/ml, both p < 0.05; NB-BAL-disease versus recovery: protein 8.1 versus 4.8 mg/ml, albumin 2.9 versus 1. 4 mg/ml, both p < 0.05). Overall, SC concentrations in ELF were not different between the diseased and normal lung, but in the NB-BAL samples, significantly higher SC concentration was noted in viral bronchiolitis and pneumonia than in noninfective lung diseases. No clear evidence of additional influx of urea into lavage fluid in association with epithelial disruption was found in the diseased lung. Comparative analysis of SC and urea revealed no difference in TA samples, but in NB-BAL specimens, urea best standardized the lavage concentration of surfactant indices to correspond to the degree of lung dysfunction as indicated by oxygenation index. We conclude that SC and urea, but not protein, albumin, or SM, are valid dilutional markers with which to estimate ELF recovery during small volume lung lavage. Urea appears a more appropriate choice in return fluid derived from the distal tracheobronchial tree, and SC should not be used in the context of lung infection.
Archives of disease in childhood. Fetal and neonatal edition, Jan 8, 2015
Oxygen saturation (SpO2) signal dropout leaves caregivers without a reliable measure to guide oxy... more Oxygen saturation (SpO2) signal dropout leaves caregivers without a reliable measure to guide oxygen therapy. We studied SpO2 dropout in preterm infants on continuous positive airway pressure, noting the SpO2 values at signal loss and recovery and thus the resultant change in SpO2, and the factors influencing this parameter. In 32 infants of median gestation 26 weeks, a total of 3932 SpO2 dropout episodes were identified (1.1 episodes/h). In the episodes overall, SpO2 decreased by 1.1%, with the SpO2 change influenced by starting SpO2 (negative correlation), but not dropout duration. For episodes starting in hypoxia (SpO2 <85%), SpO2 recovered at a median of 3.2% higher than at SpO2 dropout, with a downward trajectory in a quarter of cases. We conclude that after signal dropout SpO2 generally recovers in a relative normoxic range. Blind FiO2 adjustments are thus unlikely to be of benefit during most SpO2 dropout episodes.
This report presents two neonates with nonketotic hyperglycinemia in whom conventional magnetic r... more This report presents two neonates with nonketotic hyperglycinemia in whom conventional magnetic resonance imaging revealed structural cerebral abnormalities, diffusion-weighted imaging indicated abnormalities of myelinated white matter, and magnetic resonance spectroscopy provided biochemical evidence of elevated cerebral glycine levels. The early use of combined magnetic resonance modalities in these severely affected infants helped in prognostication and clinical management.
In newborn infants, closed endotracheal tube (ETT) suction may reduce associated adverse effects,... more In newborn infants, closed endotracheal tube (ETT) suction may reduce associated adverse effects, but it is not clear whether ventilation is maintained during the procedure. We aimed to determine the effect of ETT size, catheter size, and suction pressure on ventilation parameters measured distal to the ETT. Suction was performed on a test lung, ventilated with conventional (CMV) and high-frequency oscillatory ventilation (HFOV) using ETT sizes 2.5-4.0 mm, catheter sizes 5-8 French gauge (Fr), and suction pressures 80-200 mm Hg. Tracheal and circuit peak inspiratory pressure, positive end-expiratory pressure, and tracheal tidal volume (VT) were recorded for each suction episode. During both CMV and HFOV, tracheal pressures and VT were considerably reduced by suctioning; this reduction was dependent on the combination of ETT, catheter, and suction pressure. Loss of VT, inflation pressure (CMV), and pressure amplitude (HFOV) occurred primarily with insertion of the catheter, and loss of end-expiratory pressure (CMV) and mean tracheal pressure (HFOV) occurred with the application of suction. Circuit pressures were reduced to lesser degree. We conclude that airway pressures and VT are not maintained during closed endotracheal suction with either CMV or HFOV, and choice of equipment and settings will affect the degree of interruption to ventilation.
We sought to examine, in a large cohort of infants within a definable population of live births, ... more We sought to examine, in a large cohort of infants within a definable population of live births, the incidence, risk factors, treatments, complications, and outcomes of meconium aspiration syndrome (MAS). Data were gathered on all of the infants in Australia and New Zealand who were intubated and mechanically ventilated with a primary diagnosis of MAS (MASINT) between 1995 and 2002, inclusive. Information on all of the live births during the same time period was obtained from perinatal data registries. MASINT occurred in 1061 of 2,490,862 live births (0.43 of 1000), with a decrease in incidence from 1995 to 2002. A higher risk of MASINT was noted at advanced gestation, with 34% of cases born beyond 40 weeks, compared with 16% of infants without MAS. Fetal distress requiring obstetric intervention was noted in 51% of cases, and 42% were delivered by cesarean section. There was a striking association between low 5-minute Apgar score and MASINT. In addition, risk of MASINT was higher where maternal ethnicity was Pacific Islander or indigenous Australian and was also increased after planned home birth. Uptake of exogenous surfactant, high-frequency ventilation, and inhaled nitric oxide increased considerably during the study period, with &amp;amp;amp;amp;amp;amp;gt;50% of infants receiving &amp;amp;amp;amp;amp;amp;gt; or =1 of these therapies by 2002. Risk of air leak was 9.6% overall, with an apparent reduction to 5.3% in 2001-2002. The duration of intubation remained constant throughout the study period (median: 3 days), whereas duration of oxygen therapy and length of hospital stay increased. Death related to MAS occurred in 24 infants (2.5% of the MASINT cohort; 0.96 per 100,000 live births). The incidence of MASINT in the developed world is low and seems to be decreasing. Risk of MASINT is significantly greater in the presence of fetal distress and low Apgar score, as well as Pacific Islander and indigenous Australian ethnicity. The increased use of innovative respiratory supports has not altered the duration of mechanical ventilation.
Resuscitation of very premature lambs with positive end-expiratory pressure (PEEP) improves oxyge... more Resuscitation of very premature lambs with positive end-expiratory pressure (PEEP) improves oxygenation and reduces pulmonary blood flow (PBF). However, the effects of PEEP on blood gases and PBF have not been studied in preterm lambs receiving antenatal corticosteroids or postnatal surfactant. Lambs were delivered at 125 d of gestation (term 147 d) and ventilated with a tidal volume (VT) of 5 mL/kg using different levels of PEEP. Four treatment groups were studied: (1) antenatal betamethasone 24 and 36 h before delivery; (2) postnatal Curosurf; (3) antenatal betamethasone and postnatal Curosurf; (4) untreated controls. Blood gases, PBF, and ventilator parameters were recorded during the first 2 h. Increasing PEEP improved oxygenation even after antenatal betamethasone and postnatal Curosurf, without adverse effects on arterial PCO2. Increasing PEEP reduced PBF; this effect was not altered by betamethasone and/or Curosurf. In very preterm lambs ventilated with fixed VT, increasing levels of PEEP improved oxygenation after antenatal glucocorticoids and/or postnatal surfactant. These treatments do not alter the deleterious effects of high levels of PEEP on PBF.
The aims of the present study were (i) to characterize the relationship between mean airway press... more The aims of the present study were (i) to characterize the relationship between mean airway pressure (PAW) and reactance measured at 5 Hz (reactance of the respiratory system (X RS), forced oscillation technique) and (ii) to compare optimal PAW (P opt) defined by X RS, oxygenation, lung volume (VL), and tidal volume (VT) in preterm lambs receiving high-frequency oscillatory ventilation (HFOV). Nine 132-d gestation lambs were commenced on HFOV at PAW of 14 cmH2O (P start). PAW was increased stepwise to a maximum pressure (P max) and subsequently sequentially decreased to the closing pressure (Pcl, oxygenation deteriorated) or a minimum of 6 cmH2O, using an oxygenation-based recruitment maneuver. X RS, regional V L (electrical impedance tomography), and V T were measured immediately after (t 0 min) and 2 min after (t 2 min) each PAW decrement. P opt defined by oxygenation, X RS, V L, and V T were determined. The PAW-X RS and PAW-VT relationships were dome shaped with a maximum at Pcl+6 cmH2O, the same point as P opt defined by VL. Below Pcl+6 cmH2O, X RS became unstable between t 0 min and t 2 min and was associated with derecruitment in the dependent lung. P opt, as defined by oxygenation, was lower than the P opt defined by X RS, V L, or V T. X RS has the potential as a bedside tool for optimizing PAW during HFOV.
Positive end expiratory pressure (PEEP) is important for neonatal ventilation but is not consider... more Positive end expiratory pressure (PEEP) is important for neonatal ventilation but is not considered in guidelines for resuscitation. Our aim was to investigate the effects of PEEP on cardiorespiratory parameters during resuscitation of very premature lambs delivered by hysterotomy at approximately 125 d gestation (term approximately 147 d). Before delivery, they were intubated and lung fluid was drained. Immediately after delivery, they were ventilated with a Dräger Babylog plus ventilator in volume guarantee mode with a tidal volume of 5 mL/kg. Lambs were randomized to receive 0, 4, 8, or 12 cm H(2)O of PEEP. They were ventilated for a 15-min resuscitation period followed by 2 h of stabilization at the same PEEP. Tidal volume, peak inspiratory pressure, PEEP, arterial pressure, oxygen saturation, and blood gases were measured regularly, and respiratory system compliance and alveolar/arterial oxygen differences were calculated. Lambs that received 12 cm H(2)O of PEEP died from pneumothoraces; all others survived without pneumothoraces. Oxygenation was significantly improved by 8 and 12 cm H(2)O of PEEP compared with 0 and 4 cm H(2)O of PEEP. Lambs with 0 PEEP did not oxygenate adequately. The compliance of the respiratory system was significantly higher at 4 and 8 cm H(2)O of PEEP than at 0 PEEP. There were no significant differences in partial pressure of carbon dioxide in arterial blood between groups. Arterial pressure was highest with 8 cm H(2)O of PEEP, and there was no cardiorespiratory compromise at any level of PEEP. Applying PEEP during resuscitation of very premature infants might be advantageous and merits further investigation.
Therapeutic lung lavage is an emerging treatment for meconium aspiration syndrome (MAS), but the ... more Therapeutic lung lavage is an emerging treatment for meconium aspiration syndrome (MAS), but the ideal fluid volume and lavage technique remain unclear. To evaluate the impact of suction technique, chest squeeze and aliquot volume on the efficacy of lung lavage in MAS. MAS was induced in ventilated 2-week-old piglets using 4 ml/kg of 20% human meconium. Lung lavage with either two 8 ml/kg saline aliquots (n = 5) or a single 15 ml/kg aliquot (n = 6) was performed soon after meconium instillation. Lavage fluid was recovered by three methods performed in sequence: closed suction via a suction adaptor; open suction with the ventilator disconnected, and open suction with manual vibratory chest squeezing. Return fluid was collected separately with each method. Recovery of meconium and lavage fluid was determined and expressed as a proportion of the amount instilled. Closed suction resulted in poor meconium and fluid returns, with recovery of meconium being only 5.2 +/- (SD) 2.5% with 2 x 8 ml/kg lavage and 19 +/- 11% with a single 15 ml/kg aliquot. Chest squeeze during suction increased recovery of both meconium and lavage fluid. Overall recovery of instilled meconium was greater with 15 ml/kg lavage (45 +/- 17%) than with two 8 ml/kg aliquots (24 +/- 4.5%, p = 0.028, repeated-measures ANOVA); the corresponding values for return of lavage fluid were 73 +/- 10 and 49 +/- 13%, respectively (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01). Open suction, vibratory chest squeezing and an aliquot volume of 15 ml/kg each improve the efficacy of lung lavage in MAS, and merit inclusion in the lavage technique in clinical trials of this therapy.
Early-onset respiratory distress and a radiographic appearance of an aspiration syndrome occurred... more Early-onset respiratory distress and a radiographic appearance of an aspiration syndrome occurred in two neonates with gastroschisis who had evidence of inhalation of bile. Hypoxemic respiratory failure developed in both infants, contributing to death or prolonged respiratory morbidity. Bile aspiration syndrome should be considered whenever there is early-onset respiratory distress in a neonate with high intestinal obstruction.
Definitive analysis of solute concentrations in lung lavage fluid involves the use of a marker of... more Definitive analysis of solute concentrations in lung lavage fluid involves the use of a marker of dilution to correct for variable recovery of epithelial lining fluid (ELF), but the question of the most appropriate dilutional marker remains unresolved. In lavage fluid collected from infants with lung disease and healthy control subjects, we examined ELF concentration of protein, albumin, sphingomyelin (SM), and IgA secretory component (SC), and critically appraised the relative validity of SC and urea as dilutional markers in the context of lung infection and lung injury. Protein, albumin, and SM were found not to be valid dilutional markers, as their ELF concentration varied significantly between the diseased, recovering, and normal lung. Differences in concentration were noted in both tracheal aspirate samples (TA, 4 x 0.5 ml) and nonbronchoscopic bronchoalveolar lavage fluid (NB-BAL, 3 x 1 ml/kg), but were not uniform (e.g., TA-disease versus control: albumin 2.8 versus 0.68 mg/ml, SM 45 versus 16 microgram/ml, both p &lt; 0.05; NB-BAL-disease versus recovery: protein 8.1 versus 4.8 mg/ml, albumin 2.9 versus 1. 4 mg/ml, both p &lt; 0.05). Overall, SC concentrations in ELF were not different between the diseased and normal lung, but in the NB-BAL samples, significantly higher SC concentration was noted in viral bronchiolitis and pneumonia than in noninfective lung diseases. No clear evidence of additional influx of urea into lavage fluid in association with epithelial disruption was found in the diseased lung. Comparative analysis of SC and urea revealed no difference in TA samples, but in NB-BAL specimens, urea best standardized the lavage concentration of surfactant indices to correspond to the degree of lung dysfunction as indicated by oxygenation index. We conclude that SC and urea, but not protein, albumin, or SM, are valid dilutional markers with which to estimate ELF recovery during small volume lung lavage. Urea appears a more appropriate choice in return fluid derived from the distal tracheobronchial tree, and SC should not be used in the context of lung infection.
Archives of disease in childhood. Fetal and neonatal edition, Jan 8, 2015
Oxygen saturation (SpO2) signal dropout leaves caregivers without a reliable measure to guide oxy... more Oxygen saturation (SpO2) signal dropout leaves caregivers without a reliable measure to guide oxygen therapy. We studied SpO2 dropout in preterm infants on continuous positive airway pressure, noting the SpO2 values at signal loss and recovery and thus the resultant change in SpO2, and the factors influencing this parameter. In 32 infants of median gestation 26 weeks, a total of 3932 SpO2 dropout episodes were identified (1.1 episodes/h). In the episodes overall, SpO2 decreased by 1.1%, with the SpO2 change influenced by starting SpO2 (negative correlation), but not dropout duration. For episodes starting in hypoxia (SpO2 <85%), SpO2 recovered at a median of 3.2% higher than at SpO2 dropout, with a downward trajectory in a quarter of cases. We conclude that after signal dropout SpO2 generally recovers in a relative normoxic range. Blind FiO2 adjustments are thus unlikely to be of benefit during most SpO2 dropout episodes.
This report presents two neonates with nonketotic hyperglycinemia in whom conventional magnetic r... more This report presents two neonates with nonketotic hyperglycinemia in whom conventional magnetic resonance imaging revealed structural cerebral abnormalities, diffusion-weighted imaging indicated abnormalities of myelinated white matter, and magnetic resonance spectroscopy provided biochemical evidence of elevated cerebral glycine levels. The early use of combined magnetic resonance modalities in these severely affected infants helped in prognostication and clinical management.
In newborn infants, closed endotracheal tube (ETT) suction may reduce associated adverse effects,... more In newborn infants, closed endotracheal tube (ETT) suction may reduce associated adverse effects, but it is not clear whether ventilation is maintained during the procedure. We aimed to determine the effect of ETT size, catheter size, and suction pressure on ventilation parameters measured distal to the ETT. Suction was performed on a test lung, ventilated with conventional (CMV) and high-frequency oscillatory ventilation (HFOV) using ETT sizes 2.5-4.0 mm, catheter sizes 5-8 French gauge (Fr), and suction pressures 80-200 mm Hg. Tracheal and circuit peak inspiratory pressure, positive end-expiratory pressure, and tracheal tidal volume (VT) were recorded for each suction episode. During both CMV and HFOV, tracheal pressures and VT were considerably reduced by suctioning; this reduction was dependent on the combination of ETT, catheter, and suction pressure. Loss of VT, inflation pressure (CMV), and pressure amplitude (HFOV) occurred primarily with insertion of the catheter, and loss of end-expiratory pressure (CMV) and mean tracheal pressure (HFOV) occurred with the application of suction. Circuit pressures were reduced to lesser degree. We conclude that airway pressures and VT are not maintained during closed endotracheal suction with either CMV or HFOV, and choice of equipment and settings will affect the degree of interruption to ventilation.
We sought to examine, in a large cohort of infants within a definable population of live births, ... more We sought to examine, in a large cohort of infants within a definable population of live births, the incidence, risk factors, treatments, complications, and outcomes of meconium aspiration syndrome (MAS). Data were gathered on all of the infants in Australia and New Zealand who were intubated and mechanically ventilated with a primary diagnosis of MAS (MASINT) between 1995 and 2002, inclusive. Information on all of the live births during the same time period was obtained from perinatal data registries. MASINT occurred in 1061 of 2,490,862 live births (0.43 of 1000), with a decrease in incidence from 1995 to 2002. A higher risk of MASINT was noted at advanced gestation, with 34% of cases born beyond 40 weeks, compared with 16% of infants without MAS. Fetal distress requiring obstetric intervention was noted in 51% of cases, and 42% were delivered by cesarean section. There was a striking association between low 5-minute Apgar score and MASINT. In addition, risk of MASINT was higher where maternal ethnicity was Pacific Islander or indigenous Australian and was also increased after planned home birth. Uptake of exogenous surfactant, high-frequency ventilation, and inhaled nitric oxide increased considerably during the study period, with &amp;amp;amp;amp;amp;amp;gt;50% of infants receiving &amp;amp;amp;amp;amp;amp;gt; or =1 of these therapies by 2002. Risk of air leak was 9.6% overall, with an apparent reduction to 5.3% in 2001-2002. The duration of intubation remained constant throughout the study period (median: 3 days), whereas duration of oxygen therapy and length of hospital stay increased. Death related to MAS occurred in 24 infants (2.5% of the MASINT cohort; 0.96 per 100,000 live births). The incidence of MASINT in the developed world is low and seems to be decreasing. Risk of MASINT is significantly greater in the presence of fetal distress and low Apgar score, as well as Pacific Islander and indigenous Australian ethnicity. The increased use of innovative respiratory supports has not altered the duration of mechanical ventilation.
Resuscitation of very premature lambs with positive end-expiratory pressure (PEEP) improves oxyge... more Resuscitation of very premature lambs with positive end-expiratory pressure (PEEP) improves oxygenation and reduces pulmonary blood flow (PBF). However, the effects of PEEP on blood gases and PBF have not been studied in preterm lambs receiving antenatal corticosteroids or postnatal surfactant. Lambs were delivered at 125 d of gestation (term 147 d) and ventilated with a tidal volume (VT) of 5 mL/kg using different levels of PEEP. Four treatment groups were studied: (1) antenatal betamethasone 24 and 36 h before delivery; (2) postnatal Curosurf; (3) antenatal betamethasone and postnatal Curosurf; (4) untreated controls. Blood gases, PBF, and ventilator parameters were recorded during the first 2 h. Increasing PEEP improved oxygenation even after antenatal betamethasone and postnatal Curosurf, without adverse effects on arterial PCO2. Increasing PEEP reduced PBF; this effect was not altered by betamethasone and/or Curosurf. In very preterm lambs ventilated with fixed VT, increasing levels of PEEP improved oxygenation after antenatal glucocorticoids and/or postnatal surfactant. These treatments do not alter the deleterious effects of high levels of PEEP on PBF.
The aims of the present study were (i) to characterize the relationship between mean airway press... more The aims of the present study were (i) to characterize the relationship between mean airway pressure (PAW) and reactance measured at 5 Hz (reactance of the respiratory system (X RS), forced oscillation technique) and (ii) to compare optimal PAW (P opt) defined by X RS, oxygenation, lung volume (VL), and tidal volume (VT) in preterm lambs receiving high-frequency oscillatory ventilation (HFOV). Nine 132-d gestation lambs were commenced on HFOV at PAW of 14 cmH2O (P start). PAW was increased stepwise to a maximum pressure (P max) and subsequently sequentially decreased to the closing pressure (Pcl, oxygenation deteriorated) or a minimum of 6 cmH2O, using an oxygenation-based recruitment maneuver. X RS, regional V L (electrical impedance tomography), and V T were measured immediately after (t 0 min) and 2 min after (t 2 min) each PAW decrement. P opt defined by oxygenation, X RS, V L, and V T were determined. The PAW-X RS and PAW-VT relationships were dome shaped with a maximum at Pcl+6 cmH2O, the same point as P opt defined by VL. Below Pcl+6 cmH2O, X RS became unstable between t 0 min and t 2 min and was associated with derecruitment in the dependent lung. P opt, as defined by oxygenation, was lower than the P opt defined by X RS, V L, or V T. X RS has the potential as a bedside tool for optimizing PAW during HFOV.
Positive end expiratory pressure (PEEP) is important for neonatal ventilation but is not consider... more Positive end expiratory pressure (PEEP) is important for neonatal ventilation but is not considered in guidelines for resuscitation. Our aim was to investigate the effects of PEEP on cardiorespiratory parameters during resuscitation of very premature lambs delivered by hysterotomy at approximately 125 d gestation (term approximately 147 d). Before delivery, they were intubated and lung fluid was drained. Immediately after delivery, they were ventilated with a Dräger Babylog plus ventilator in volume guarantee mode with a tidal volume of 5 mL/kg. Lambs were randomized to receive 0, 4, 8, or 12 cm H(2)O of PEEP. They were ventilated for a 15-min resuscitation period followed by 2 h of stabilization at the same PEEP. Tidal volume, peak inspiratory pressure, PEEP, arterial pressure, oxygen saturation, and blood gases were measured regularly, and respiratory system compliance and alveolar/arterial oxygen differences were calculated. Lambs that received 12 cm H(2)O of PEEP died from pneumothoraces; all others survived without pneumothoraces. Oxygenation was significantly improved by 8 and 12 cm H(2)O of PEEP compared with 0 and 4 cm H(2)O of PEEP. Lambs with 0 PEEP did not oxygenate adequately. The compliance of the respiratory system was significantly higher at 4 and 8 cm H(2)O of PEEP than at 0 PEEP. There were no significant differences in partial pressure of carbon dioxide in arterial blood between groups. Arterial pressure was highest with 8 cm H(2)O of PEEP, and there was no cardiorespiratory compromise at any level of PEEP. Applying PEEP during resuscitation of very premature infants might be advantageous and merits further investigation.
Therapeutic lung lavage is an emerging treatment for meconium aspiration syndrome (MAS), but the ... more Therapeutic lung lavage is an emerging treatment for meconium aspiration syndrome (MAS), but the ideal fluid volume and lavage technique remain unclear. To evaluate the impact of suction technique, chest squeeze and aliquot volume on the efficacy of lung lavage in MAS. MAS was induced in ventilated 2-week-old piglets using 4 ml/kg of 20% human meconium. Lung lavage with either two 8 ml/kg saline aliquots (n = 5) or a single 15 ml/kg aliquot (n = 6) was performed soon after meconium instillation. Lavage fluid was recovered by three methods performed in sequence: closed suction via a suction adaptor; open suction with the ventilator disconnected, and open suction with manual vibratory chest squeezing. Return fluid was collected separately with each method. Recovery of meconium and lavage fluid was determined and expressed as a proportion of the amount instilled. Closed suction resulted in poor meconium and fluid returns, with recovery of meconium being only 5.2 +/- (SD) 2.5% with 2 x 8 ml/kg lavage and 19 +/- 11% with a single 15 ml/kg aliquot. Chest squeeze during suction increased recovery of both meconium and lavage fluid. Overall recovery of instilled meconium was greater with 15 ml/kg lavage (45 +/- 17%) than with two 8 ml/kg aliquots (24 +/- 4.5%, p = 0.028, repeated-measures ANOVA); the corresponding values for return of lavage fluid were 73 +/- 10 and 49 +/- 13%, respectively (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01). Open suction, vibratory chest squeezing and an aliquot volume of 15 ml/kg each improve the efficacy of lung lavage in MAS, and merit inclusion in the lavage technique in clinical trials of this therapy.
Early-onset respiratory distress and a radiographic appearance of an aspiration syndrome occurred... more Early-onset respiratory distress and a radiographic appearance of an aspiration syndrome occurred in two neonates with gastroschisis who had evidence of inhalation of bile. Hypoxemic respiratory failure developed in both infants, contributing to death or prolonged respiratory morbidity. Bile aspiration syndrome should be considered whenever there is early-onset respiratory distress in a neonate with high intestinal obstruction.
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