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O'Donnell CPF, Davis PG, Lau R, Dargaville PA, Doyle LW, Morley CJ. Neonatal resuscitation 3: manometer use in a model of face mask ventilation. Arch Dis Child Fetal Neonatal Ed 2005; 90:F397-400. [PMID: 15871988 PMCID: PMC1721943 DOI: 10.1136/adc.2004.064709] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Adequate ventilation is the key to successful neonatal resuscitation. Positive pressure ventilation (PPV) is initiated with manual ventilation devices via face masks. These devices may be used with a manometer to measure airway pressures delivered. The expiratory tidal volume measured at the mask (V(TE(mask))) is a good estimate of the tidal volume delivered during simulated neonatal resuscitation. AIM To assess the effect of viewing a manometer on the peak inspiratory pressures used, the volume delivered, and leakage from the face mask during PPV with two manual ventilation devices in a model of neonatal resuscitation. METHODS Participants gave PPV to a modified resuscitation mannequin using a Laerdal infant resuscitator and a Neopuff infant resuscitator at specified pressures ensuring adequate chest wall excursion. Each participant gave PPV to the mannequin with each device twice, viewing the manometer on one occasion and unable to see the manometer on the other. Data from participants were averaged for each device used with the manometer and without the manometer separately. RESULTS A total of 7767 inflations delivered by the 18 participants were recorded and analysed. Peak inspiratory pressures delivered were lower with the Laerdal device. There were no differences in leakage from the face mask or volumes delivered. Whether or not the manometer was visible made no difference to any measured variable. CONCLUSIONS Viewing a manometer during PPV in this model of neonatal resuscitation does not affect the airway pressure or tidal volumes delivered or the degree of leakage from the face mask.
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McCallion N, Lau R, Dargaville PA, Morley CJ. Volume guarantee ventilation, interrupted expiration, and expiratory braking. Arch Dis Child 2005; 90:865-70. [PMID: 15886260 PMCID: PMC1720535 DOI: 10.1136/adc.2004.061390] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND In volume guarantee ventilation with the Dräger Babylog 8000 ventilator, inspiratory and expiratory flows are monitored and the expiratory tidal volume calculated following each inflation. The pressure for the next inflation is modified to ensure the expired tidal volume is close to the set value. AIM To investigate interrupted expiration observed during volume guarantee ventilation of spontaneously breathing, ventilated infants. METHODS Spontaneously breathing infants, ventilated with volume guarantee, had recordings of gas flow, ventilator pressures, tidal volume waveforms, oximetry, heart rate, and transcutaneous oxygen and carbon dioxide during 10 minute recordings. RESULTS A total of 6540 inflations were analysed from 10 infants; 62% were triggered. Two different patterns were found: (1) Normal volume guarantee pattern with 97% of triggered and 91% untriggered inflations. It had a normal expiratory curve and a mean expired tidal volume within 3% of the set volume, but a large variation due to the babies' breathing. (2) A pattern of interrupted expiratory flow after approximately 3% of inflations due to a small inspiration (approximately 1.3 ml/kg) during expiration. This led the ventilator to calculate an inappropriate total expired tidal volume for that inflation and an increase in the pressure for the next inflation. CONCLUSIONS After about 3% of inflations, with volume guarantee ventilation, interruption of the expiration causes an increased pressure for the next inflation of approximately 4.9 cm H2O, compared with normal volume guarantee inflation. The interrupted expiration is most likely to be due to diaphragmatic braking.
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Shah DK, Tingay DG, Fink AM, Hunt RW, Dargaville PA. Magnetic resonance imaging in neonatal nonketotic hyperglycinemia. Pediatr Neurol 2005; 33:50-2. [PMID: 15993321 DOI: 10.1016/j.pediatrneurol.2005.01.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2004] [Revised: 12/10/2004] [Accepted: 01/04/2005] [Indexed: 10/25/2022]
Abstract
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.
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Abstract
Meconium aspiration syndrome (MAS) is an important cause of respiratory distress in the term infant. Therapy for the disease remains problematic, and newer treatments such as high-frequency ventilation and inhaled nitric oxide are being applied with increasing frequency. There is a significant disturbance of the pulmonary surfactant system in MAS, with a wealth of experimental data indicating that inhibition of surfactant function in the alveolar space is an important element of the pathophysiology of the disease. This inhibition may be mediated by meconium, plasma proteins, haemoglobin and oedema fluid, and, at least in vitro, can be overcome by increasing surfactant phospholipid concentration. These observations have served as the rationale for administration of exogenous surfactant preparations in MAS, initially as standard bolus therapy and, more recently, in association with therapeutic lung lavage. Bolus surfactant therapy in ventilated infants with MAS has been found to improve oxygenation in most studies, although there are a significant proportion of nonresponders and in many cases the effect is transient. Pooled data from randomised controlled trials of surfactant therapy suggest a benefit in terms of a reduction in the requirement for extracorporeal membrane oxygenation (relative risk 0.48 in surfactant-treated infants) but no diminution of air leak or ventilator days. Current evidence would support the use of bolus surfactant therapy on a case by case basis in nurseries with a relatively high mortality associated with MAS, or the lack of availability of other forms of respiratory support such as high-frequency ventilation or nitric oxide. If used, bolus surfactant should be administered as early as practicable to infants who exhibit significant parenchymal disease, at a phospholipid dose of at least 100 mg/kg, rapidly instilled into the trachea. Natural surfactant or a third-generation synthetic surfactant should be used and the dosage repeated every 6 hours until oxygenation has improved. Lung lavage with dilute surfactant has recently emerged as an alternative to bolus therapy in MAS, which has the advantage of removing surfactant inhibitors from the alveolar space in addition to augmenting surfactant phospholipid concentration. Combined animal and human data suggest that lung lavage can remove significant amounts of meconium and alveolar debris, and thereby improve oxygenation and pulmonary mechanics. Arterial oxygen saturation inevitably falls during lavage but has been noted to recover relatively rapidly, even in infants with severe disease. Several randomised controlled trials of surfactant lavage in MAS are underway, and until the results are known, lavage must be considered an unproven and experimental therapy.
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Probyn ME, Hooper SB, Dargaville PA, McCallion N, Crossley K, Harding R, Morley CJ. Positive end expiratory pressure during resuscitation of premature lambs rapidly improves blood gases without adversely affecting arterial pressure. Pediatr Res 2004; 56:198-204. [PMID: 15181198 DOI: 10.1203/01.pdr.0000132752.94155.13] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
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.
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Bryant PA, Tingay D, Dargaville PA, Starr M, Curtis N. Neonatal coxsackie B virus infection-a treatable disease? Eur J Pediatr 2004; 163:223-8. [PMID: 14986123 DOI: 10.1007/s00431-004-1408-y] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2003] [Accepted: 01/08/2004] [Indexed: 10/26/2022]
Abstract
UNLABELLED Ten neonates with coxsackie B viral infection presented over a 3-month period. Clinical features included meningoencephalitis, thrombocytopenia, disseminated intravascular coagulopathy, cardiomyopathy, and hepatitis. Eight infants had multiorgan disease, four with severe myocardial dysfunction, of whom two died. All of the infants with severe disease developed symptoms within 7 days of age. In infants presenting within 10 days of birth, in all cases there were symptoms compatible with maternal infection prior to delivery. Severity was associated with perinatal transmission. Enteroviral polymerase chain reaction of CSF, urine, stool or throat swab was positive in nine of the ten babies. Seven of the infants were treated with a 7-day course of the new anti-picornaviral drug pleconaril (5 mg/kg 3 times daily). CONCLUSION These cases highlight the importance of not missing coxsackie B viral infection in the differential diagnosis of the septic neonate, especially as there is now a potential treatment.
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Abstract
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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Jamshidi N, Macciocca I, Dargaville PA, Thomas P, Kilpatrick N, McKinlay Gardner RJ, Farlie PG. Isolated Robin sequence associated with a balanced t(2;17) chromosomal translocation. J Med Genet 2004; 41:e1. [PMID: 14729841 PMCID: PMC1757243 DOI: 10.1136/jmg.2003.010157] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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109
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De Paoli AG, Dargaville PA, O'Donnell CPF, Casalaz DM, Taylor RG, Coombs CJ, Morley CJ. Embolization of cannula fragments during insertion of central catheters. J Pediatr 2003; 143:690-1. [PMID: 14649664 DOI: 10.1067/s0022-3476(03)00394-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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110
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Frerichs I, Dargaville PA, Dudykevych T, Rimensberger PC. Electrical impedance tomography: a method for monitoring regional lung aeration and tidal volume distribution? Intensive Care Med 2003; 29:2312-2316. [PMID: 14566457 DOI: 10.1007/s00134-003-2029-z] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2003] [Accepted: 09/08/2003] [Indexed: 10/26/2022]
Abstract
OBJECTIVE To demonstrate the monitoring capacity of modern electrical impedance tomography (EIT) as an indicator of regional lung aeration and tidal volume distribution. DESIGN AND SETTING Short-term ventilation experiment in an animal research laboratory. PATIENTS AND PARTICIPANTS One newborn piglet (body weight: 2 kg). INTERVENTIONS Surfactant depletion by repeated bronchoalveolar lavage, surfactant administration. MEASUREMENTS AND RESULTS EIT scanning was performed at an acquisition rate of 13 images/s during two ventilatory manoeuvres performed before and after surfactant administration. During the scanning periods of 120 s the piglet was ventilated with a tidal volume of 10 ml/kg at positive end-expiratory pressures (PEEP) in the range of 0-30 cmH(2)O, increasing and decreasing in 5 cmH(2)O steps. Local changes in aeration and ventilation with PEEP were visualised by EIT scans showing the regional shifts in end-expiratory lung volume and distribution of tidal volume, respectively. In selected regions of interest EIT clearly identified the changes in local aeration and tidal volume distribution over time and after surfactant treatment as well as the differences between stepwise inflation and deflation. CONCLUSIONS Our data indicate that modern EIT devices provide an assessment of regional lung aeration and tidal volume and allow evaluation of immediate effects of a change in ventilation or other therapeutic intervention. Future use of EIT in a clinical setting is expected to optimise the selection of appropriate ventilation strategies.
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Dargaville PA, Mills JF, Headley BM, Chan Y, Coleman L, Loughnan PM, Morley CJ. Therapeutic lung lavage in the piglet model of meconium aspiration syndrome. Am J Respir Crit Care Med 2003; 168:456-63. [PMID: 12714351 DOI: 10.1164/rccm.200301-121oc] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Therapeutic lung lavage is an emerging treatment for meconium aspiration syndrome. Our objective was to investigate the type of fluid and aliquot volume most appropriate for lung lavage in this condition. Meconium injury was induced in 2-week-old piglets, followed by a 30 ml/kg lavage in two aliquots 40 minutes later. Lavage with either dilute bovine surfactant (2.5 mg/ml) or a perfluorocarbon emulsion (20% wt/vol) improved oxygenation compared with a nonlavaged control group, but only with dilute surfactant was there a sustained improvement in oxygenation (alveolar-arterial oxygen difference at 5 hours: dilute surfactant 250 mm Hg; perfluorocarbon emulsion 460 mm Hg; controls 460 mm Hg; p = 0.0031). There was histologic and biochemical evidence of decreased lung injury in the dilute surfactant group. In a further study, 30 ml/kg dilute surfactant lavage was performed 40 minutes after meconium injury using either two aliquots of 15 ml/kg, or multiple 3-ml aliquots. Aliquot volume of 15 ml/kg was associated with increased meconium removal, better post-lavage lung function, and less lung injury. Dilute surfactant lavage using two 15-ml/kg aliquots is an effective therapy in the piglet model of meconium aspiration, and should be evaluated in human infants with this condition.
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112
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Gordon E, South M, McDougall PN, Dargaville PA. Blood aspiration syndrome as a cause of respiratory distress in the newborn infant. J Pediatr 2003; 142:200-2. [PMID: 12584546 DOI: 10.1067/mpd.2003.36] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Early-onset respiratory distress and a radiographic appearance of an aspiration syndrome occurred in three neonates who had not passed meconium before delivery. In each case there was evidence of inhalation of blood, associated with very high plasma protein concentration in lung fluid. Blood aspiration syndrome is a distinct diagnostic entity that can result in significant respiratory distress in the neonate.
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113
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Frawley GP, Dargaville PA, Mitchell PJ, Tress BM, Loughnan P. Clinical course and medical management of neonates with severe cardiac failure related to vein of Galen malformation. Arch Dis Child Fetal Neonatal Ed 2002; 87:F144-9. [PMID: 12193525 PMCID: PMC1721464 DOI: 10.1136/fn.87.2.f144] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND Neonatal presentation of vein of Galen aneurysmal malformations (VGAMs) with intractable cardiac failure is considered a poor prognostic sign. Interventional neuroradiology with embolisation has been shown to control cardiac failure, but there is a perception that neurological outcome in survivors is poor. OBJECTIVE To determine if aggressive intensive care and anaesthetic management of cardiac failure before urgent embolisation can influence morbidity and mortality. PATIENTS Nine newborns (four boys, five girls) were diagnosed with symptomatic vein of Galen malformations in the neonatal period during the period 1996-2001. Eight developed intractable high output cardiac failure requiring initial endovascular treatment in the first week of life. RESULTS The immediate outcome after a series of endovascular procedures was control of cardiac failure and normal neurological function in six (66%) patients, one death from intractable cardiac failure in the neonatal period, and two late deaths with severe hypoxic-ischaemic neurological injury (33% mortality). Clinical review at 6 months to 4 years of age showed five infants with no evidence of neurological abnormality or cardiac failure and one child with mild developmental delay (11%). CONCLUSIONS Aggressive medical treatment of cardiac failure and early neurointervention combined with modern neuroanaesthetic care results in good survival rates with low morbidity even in cases of high risk VGAM presenting in the immediate perinatal period with cardiac failure. Systemic arterial vasodilators improve outcome in neonates with cardiac failure secondary to VGAM. Excessive beta adrenergic stimulation induced by conventional inotropic agents may exacerbate systemic hypoperfusion.
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114
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Dargaville PA, Mills JF, Soll R. Therapeutic lung lavage for meconium aspiration syndrome in newborn infants. THE COCHRANE DATABASE OF SYSTEMATIC REVIEWS 2002. [DOI: 10.1002/14651858.cd003486] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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115
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Mills J, Dargaville PA. Economic evaluation of prophylaxis against respiratory syncytial virus infection in at-risk infants. J Paediatr Child Health 2001; 37:317-9. [PMID: 11468056 DOI: 10.1046/j.1440-1754.2001.0681b.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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116
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Headley BM, McDougall PN, Stokes KB, Dewan PA, Dargaville PA. Left-lung-collapse bronchial deformation in giant omphalocele. J Pediatr Surg 2001; 36:846-50. [PMID: 11381409 DOI: 10.1053/jpsu.2001.23951] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Five infants with giant omphalocele had persistent collapse of the left lung and required prolonged respiratory support. Narrowing of the left main bronchus, reversible with positive end-expiratory pressure, was identified radiographically in 3 infants, and we postulate that this relates to distortion of the bronchus within the constraints of the elongated, narrow thoracic cavity characteristic of these patients. The lung collapse may be precipitated by manipulation (reduction or attempted reduction) of the omphalocele. J Pediatr Surg 36:846-850.
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117
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Mills JF, Dargaville PA, Coleman LT, Rosenfeld JV, Ekert PG. Upper cervical spinal cord injury in neonates: the use of magnetic resonance imaging. J Pediatr 2001; 138:105-8. [PMID: 11148521 DOI: 10.1067/mpd.2001.109195] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Neonatal upper cervical spinal cord injury is associated with rotational forceps delivery and presents with quadriparesis and diaphragmatic paralysis. The underlying pathology determines neurologic outcome but is difficult to assess clinically or with simple radiographic techniques. We report 4 cases in which early magnetic resonance imaging demonstrated the extent and severity of the injury and guided management.
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118
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Abstract
Surfactant indices and inhibitors were measured in lung lavage fluid from 8 infants with meconium aspiration syndrome (MAS) who were receiving mechanical ventilation and 11 healthy control subjects. Surfactant phospholipid and surfactant protein A content in MAS was not different from that of control subjects, but concentrations of total protein, albumin, and membrane-derived phospholipid were elevated. All infants with MAS had hemorrhagic pulmonary edema. These findings reinforce the notion of MAS as a toxic pneumonitis with epithelial disruption and proteinaceous exudation.
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Abstract
Inhibition of the function of pulmonary surfactant in the alveolar space is an important element of the pathophysiology of many lung diseases, including meconium aspiration syndrome, pneumonia and acute respiratory distress syndrome. The known mechanisms by which surfactant dysfunction occurs are (a) competitive inhibition of phospholipid entry into the surface monolayer (e.g. by plasma proteins), and (b) infiltration and destabilization of the surface film by extraneous lipids (e.g. meconium-derived free fatty acids). Recent data suggest that addition of non-ionic polymers such as dextran and polyethylene glycol to surfactant mixtures may significantly improve resistance to inhibition. Polymers have been found to neutralize the effects of several different inhibitors, and can produce near-complete restoration of surfactant function. The anti-inhibitory properties of polymers, and their possible role as an adjunct to surfactant therapy, deserve further exploration.
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120
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Millar KJ, Dargaville PA, South M. Pulmonary surfactant and cardiopulmonary bypass in infants. J Thorac Cardiovasc Surg 2000; 119:192-3. [PMID: 10612793 DOI: 10.1016/s0022-5223(00)70250-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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121
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Dargaville PA, South M, Vervaart P, McDougall PN. Validity of markers of dilution in small volume lung lavage. Am J Respir Crit Care Med 1999; 160:778-84. [PMID: 10471596 DOI: 10.1164/ajrccm.160.3.9811049] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
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.
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Dargaville PA, South M, McDougall PN. Comparison of two methods of diagnostic lung lavage in ventilated infants with lung disease. Am J Respir Crit Care Med 1999; 160:771-7. [PMID: 10471595 DOI: 10.1164/ajrccm.160.3.9811048] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The methods of nonbronchoscopic lung lavage used for collection of samples of epithelial lining fluid (ELF) in intubated patients are poorly standardized and incompletely validated. In infants with lung disease requiring ventilatory support, we evaluated two techniques of small volume saline lavage for the collection of a specimen suitable for pulmonary surfactant analysis. We aimed to compare apparent origin of the return fluid obtained by each method, equivalence and agreement of the estimates of measured pulmonary surfactant concentration, and the relative strength of association between surfactant indices and lung dysfunction. Fifty-three contemporaneous paired samples of lung lavage fluid suitable for surfactant analysis were collected from 31 infants using tracheal aspirate (TA, 4 x 0.5 ml saline), and then nonbronchoscopic bronchoalveolar lavage (NB-BAL, 3 x 1 ml/kg). Return fluid from TA had higher mean ELF concentration of total protein and IgA secretory component (SC), and a lower surfactant protein A (SP-A) concentration than NB-BAL, indicating that the TA lavage was sampling ELF more proximally in the tracheobronchial tree (protein: TA 7.7 versus NB-BAL 4.7 mg/ml; SC: 21 versus 1.8 microgram/ml; SP-A: 9.8 versus 19 microgram/ml; all p < 0.01). Mean concentration of surfactant indices in ELF differed only for SP-A, but for all indices, paired values showed poor agreement on Bland-Altman analysis, highlighting the potential imprecision associated with small volume lung lavage. TA return fluid yielded estimates of surfactant indices which were at least equivalent to NB-BAL in prediction of the severity of lung dysfunction. We conclude that NB-BAL return fluid has more distal origin, but analysis of TA fluid may have equal validity in the estimation of indices of pulmonary surfactant. The results of individual estimates of ELF constituents in a single sample of lavage fluid should be interpreted with caution, even when standardized sampling techniques are employed.
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123
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Morrison KE, Slocombe RF, McKane SA, Dargaville PA. Functional and compositional changes in pulmonary surfactant in response to exercise. Equine Vet J 1999:62-6. [PMID: 10659224 DOI: 10.1111/j.2042-3306.1999.tb05190.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Pulmonary surfactant from bronchoalveolar lavages was obtained from 2 groups of horses. A control group consisting of 6 healthy racehorses that were paddock-rested and lavaged weekly for 6 consecutive weeks were compared with an experimental group of 10 healthy racehorses, lavaged weekly the same period, consisting of a 5 week incremental-intensity treadmill training programme and one week post training paddock rest. Phospholipid content of lavage fluid was determined indirectly by phosphorus assay, and surfactant functional activity was determined by bubble surfactometry. Total cell counts and differential cell percentages of lavage fluid were adjusted to reflect the dilution of alveolar epithelial lining fluid (ELF) using the lavage/serum urea ratio, and data were analysed per volume of ELF. There was no change in phospholipid content for either group, but some horses had consistently greater amounts than did others, ranging from 17.2-64.4 micrograms/microliter. From the exercised group ELF had both increased nucleated cell numbers due to increased macrophage numbers, and increased numbers of erythrocytes. Surface tension increased significantly over the exercise protocol, but not in controls. Functional activity of surfactant varied between horses, independent of phospholipid content, with average values for individuals ranging 10.5-29.5 mN/m. We conclude that exercise of sufficient intensity to induce intrapulmonary haemorrhage also leads to functional decrease in surfactant activity, without affecting phospholipid content. This study also indicates that functional differences in surfactant exist between horses and may be a risk factor for development of exercise-induced pulmonary haemorrhage.
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Dargaville PA, Campbell NT. Overdose of ergometrine in the newborn infant: acute symptomatology and long-term outcome. J Paediatr Child Health 1998; 34:83-9. [PMID: 9568949 DOI: 10.1046/j.1440-1754.1998.00160.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE To document the short- and long-term effects of accidental administration of ergometrine in adult dosage to the newborn infant. METHODS The case records of all infants admitted to the Royal Children's Hospital (RCH) since 1970 with a diagnosis of acute ergometrine overdose were reviewed, and details of the acute symptomatology, management, and the neurodevelopmental outcome at follow-up were noted. Similar information was obtained, where available, from previous case reports, and from two major drug information services. Additionally, data relating to administration of uterotonic agents and vitamin K were collected from tertiary perinatal centres around Australia. RESULTS Seven cases of neonatal ergometrine overdose were identified at RCH. The major features of the acute toxicity syndrome were: encephalopathy (100% RCH cases, 79% combined cases); seizures (100%, 70%); peripheral vascular disturbances (100%, 83%); and oliguria (43%, 34%). Other important symptoms were hypoxaemia, hypertension and feed intolerance. 86% of RCH cases (72% overall) required ventilatory support. Virtually all symptoms resolved within 4 days, and 86% of RCH infants (86% all cases) were neurologically intact at the time of discharge. Long-term neurodevelopmental outcome was normal in 100% of RCH infants (n=6). All the perinatal centres surveyed give vitamin K in the labour ward soon after delivery, and 7 of 18 (39%) reported using Syntometrine (ergometrine 0.5 mg, Syntocinon 5 IU) routinely during the third stage of labour. Thus the circumstances in which ergometrine overdose can occur still exist in many labour wards around the country. CONCLUSIONS Despite the catastrophic initial presentation, the long-term prognosis after neonatal ergometrine overdose appears to be favourable. To prevent further cases of this life-threatening drug error, we recommend that administration of vitamin K be deferred until just prior to, or shortly after, transfer of the newborn infant to the postnatal ward.
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Dargaville PA, South M, McDougall PN. Pulmonary surfactant concentration during transition from high frequency oscillation to conventional mechanical ventilation. J Paediatr Child Health 1997; 33:517-21. [PMID: 9484684 DOI: 10.1111/j.1440-1754.1997.tb01662.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVE To test the hypothesis that conventional mechanical ventilation (CV) provides a greater stimulus to secretion of pulmonary surfactant than high frequency oscillatory ventilation (HFO). METHODOLOGY Sequential examination of surfactant indices in lung lavage fluid in a group of six infants with severe lung disease (group 1), ventilated with HFO and then converted back to CV as their lung disease recovered. A similar group of 10 infants (group 2) ventilated conventionally throughout the course of their illness were studied for comparison. In groups 1 and 2, two sequential tracheal aspirate samples were taken, the first once lung disease was noted to be improving, and the second 48-72 h later. Group 1 infants had converted from HFO to CV during this time. RESULTS A marked increase in concentration of total surfactant phospholipid (PL) and disaturated phosphatidylcholine (DSPC) was seen in group 1 after transition from HFO to CV; the magnitude of this increase was significantly greater than that sequentially observed in group II (total PL: 9.4-fold increase in group 1 vs 1.8-fold in group 2, P = 0.006; DSPC: group 1 6.4-fold increase vs. group 2 1.7-fold, P = 0.02). CONCLUSION These findings suggest that intermittent lung inflation during CV produces more secretion of surfactant phospholipid than continuous alveolar distension on HFO, and raise the possibility that conservation and additional maturation of surfactant elements may occur when the injured lung is ventilated with HFO.
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Abstract
To determine whether abnormalities of pulmonary surfactant occur in infants with acute viral bronchiolitis, surfactant indices were measured in lung lavage fluid from 12 infants with severe bronchiolitis and eight infants without lung disease. Compared with controls, the bronchiolitis group showed deficiency of surfactant protein A (1.02 v 14.4 micrograms/ml) and disaturated phosphatidylcholine (35 v 1060 micrograms/ml) which resolved as the disease improved. Surfactant functional activity was also impaired (minimum surface tension 22 v 17 mN/m). These findings indicate that surfactant abnormalities occur in bronchiolitis, and may represent one of the pathophysiological mechanisms causing airway obstruction.
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