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Dargaville PA. Administering surfactant without intubation - what does the laryngeal mask offer us? J Pediatr (Rio J) 2017; 93:313-316. [PMID: 28214387 DOI: 10.1016/j.jped.2017.02.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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Dargaville PA. Administering surfactant without intubation – what does the laryngeal mask offer us? JORNAL DE PEDIATRIA (VERSÃO EM PORTUGUÊS) 2017. [DOI: 10.1016/j.jpedp.2017.02.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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Plottier GK, Wheeler KI, Ali SKM, Fathabadi OS, Jayakar R, Gale TJ, Dargaville PA. Clinical evaluation of a novel adaptive algorithm for automated control of oxygen therapy in preterm infants on non-invasive respiratory support. Arch Dis Child Fetal Neonatal Ed 2017; 102:F37-F43. [PMID: 27573518 DOI: 10.1136/archdischild-2016-310647] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 08/01/2016] [Accepted: 08/02/2016] [Indexed: 11/03/2022]
Abstract
OBJECTIVE To evaluate the performance of a novel rapidly responsive proportional-integral-derivative (PID) algorithm for automated oxygen control in preterm infants with respiratory insufficiency. DESIGN Interventional study of a 4-hour period of automated oxygen control compared with combined data from two flanking periods of manual control (4 hours each). SETTING Neonatal intensive care unit. PARTICIPANTS Preterm infants (n=20) on non-invasive respiratory support and supplemental oxygen, with oxygen saturation (SpO2) target range 90%-94% (manual control) and 91%-95% (automated control). Median gestation at birth 27.5 weeks (IQR 26-30 weeks), postnatal age 8.0 (1.8-34) days. INTERVENTION Automated oxygen control using a standalone device, receiving SpO2 input from a standard oximeter and computing alterations to oxygen concentration that were actuated with a modified blender. The PID algorithm was enhanced to avoid iatrogenic hyperoxaemia and adapt to the severity of lung dysfunction. MAIN OUTCOME MEASURE Proportion of time in the SpO2 target range, or above target range when in air. RESULTS Automated oxygen control resulted in more time in the target range or above in air (manual 56 (48-63)% vs automated 81 (76-90)%, p<0.001) and less time at both extremes of oxygenation. Prolonged episodes of hypoxaemia and hyperoxaemia were virtually eliminated. The control algorithm showed benefit in every infant. Manual changes to oxygen therapy were infrequent during automated control (0.24/hour vs 2.3/hour during manual control), and oxygen requirements were unchanged (automated control period 27%, manual 27% and 26%, p>0.05). CONCLUSIONS The novel PID algorithm was very effective for automated oxygen control in preterm infants, and deserves further investigation.
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Dargaville PA, Sadeghi Fathabadi O, Plottier GK, Lim K, Wheeler KI, Jayakar R, Gale TJ. Development and preclinical testing of an adaptive algorithm for automated control of inspired oxygen in the preterm infant. Arch Dis Child Fetal Neonatal Ed 2017; 102:F31-F36. [PMID: 27634820 DOI: 10.1136/archdischild-2016-310650] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 08/21/2016] [Accepted: 08/22/2016] [Indexed: 01/17/2023]
Abstract
OBJECTIVE To assess the performance of a novel algorithm for automated oxygen control using a simulation of oxygenation founded on in vivo data from preterm infants. METHODS A proportional-integral-derivative (PID) control algorithm was enhanced by (i) compensation for the non-linear SpO2-PaO2 relationship, (ii) adaptation to the severity of lung dysfunction and (iii) error attenuation within the target range. Algorithm function with and without enhancements was evaluated by iterative linking with a computerised simulation of oxygenation. Data for this simulation (FiO2 and SpO2 at 1 Hz) were sourced from extant recordings from preterm infants (n=16), and converted to a datastream of values for ventilation:perfusion ratio and shunt. Combination of this datastream second by second with the FiO2 values from the algorithm under test produced a sequence of novel SpO2 values, allowing time in the SpO2 target range (91%-95%) and in various degrees of hypoxaemia and hyperoxaemia to be determined. A PID algorithm with 30 s lockout after each FiO2 adjustment, and a proportional-derivative (PD) algorithm were also evaluated. RESULTS Separate addition of each enhancing feature to the PID algorithm showed a benefit, but not with uniformly positive effects. The fully enhanced algorithm was optimal for the combination of targeting the desired SpO2 range and avoiding time in, and episodes of, hypoxaemia and hyperoxaemia. This algorithm performed better than one with a 30 s lockout, and considerably better than PD control. CONCLUSIONS An enhanced PID algorithm was very effective for automated oxygen control in a simulation of oxygenation, and deserves clinical evaluation.
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Dargaville PA, Gerber A, Johansson S, De Paoli AG, Kamlin COF, Orsini F, Davis PG. Incidence and Outcome of CPAP Failure in Preterm Infants. Pediatrics 2016; 138:peds.2015-3985. [PMID: 27365307 DOI: 10.1542/peds.2015-3985] [Citation(s) in RCA: 126] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/21/2016] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND AND OBJECTIVES Data from clinical trials support the use of continuous positive airway pressure (CPAP) for initial respiratory management in preterm infants, but there is concern regarding the potential failure of CPAP support. We aimed to examine the incidence and explore the outcomes of CPAP failure in Australian and New Zealand Neonatal Network data from 2007 to 2013. METHODS Data from inborn preterm infants managed on CPAP from the outset were analyzed in 2 gestational age ranges (25-28 and 29-32 completed weeks). Outcomes after CPAP failure (need for intubation <72 hours) were compared with those succeeding on CPAP using adjusted odds ratios (AORs). RESULTS Within the cohort of 19 103 infants, 11 684 were initially managed on CPAP. Failure of CPAP occurred in 863 (43%) of 1989 infants commencing on CPAP at 25-28 weeks' gestation and 2061 (21%) of 9695 at 29-32 weeks. CPAP failure was associated with a substantially higher rate of pneumothorax, and a heightened risk of death, bronchopulmonary dysplasia (BPD) and other morbidities compared with those managed successfully on CPAP. The incidence of death or BPD was also increased: (25-28 weeks: 39% vs 20%, AOR 2.30, 99% confidence interval 1.71-3.10; 29-32 weeks: 12% vs 3.1%, AOR 3.62 [2.76-4.74]). The CPAP failure group had longer durations of respiratory support and hospitalization. CONCLUSIONS CPAP failure in preterm infants is associated with increased risk of mortality and major morbidities, including BPD. Strategies to promote successful CPAP application should be pursued vigorously.
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Dargaville PA. Inflammation in meconium aspiration syndrome-One of many heads of the hydra. Pediatr Pulmonol 2016; 51:555-6. [PMID: 26773259 DOI: 10.1002/ppul.23382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Revised: 12/11/2015] [Accepted: 01/04/2016] [Indexed: 11/07/2022]
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Fathabadi OS, Gale T, Wheeler K, Plottier G, Owen LS, Olivier JC, Dargaville PA. Hypoxic events and concomitant factors in preterm infants on non-invasive ventilation. J Clin Monit Comput 2016; 31:427-433. [DOI: 10.1007/s10877-016-9847-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Accepted: 02/16/2016] [Indexed: 11/30/2022]
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Sadeghi Fathabadi O, Gale TJ, Lim K, Salmon BP, Dawson JA, Wheeler KI, Olivier JC, Dargaville PA. Characterisation of the Oxygenation Response to Inspired Oxygen Adjustments in Preterm Infants. Neonatology 2016; 109:37-43. [PMID: 26554825 DOI: 10.1159/000440642] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 08/25/2015] [Indexed: 11/19/2022]
Abstract
BACKGROUND Oxygen saturation (SpO2) targeting in the preterm infant may be improved with a better understanding of the SpO2 responses to changes in inspired oxygen (FiO2). OBJECTIVE We investigated the first-order FiO2-SpO2 relationship, aiming to quantify the parameters governing that relationship, the influences on these parameters and their variability. METHODS In recordings of FiO2 and SpO2 from preterm infants on continuous positive airway pressure and supplemental oxygen, we identified unique FiO2 adjustments and mapped the subsequent SpO2 responses. For responses identified as first-order, the delay, time constant and gain parameters were determined. Clinical and physiological predictors of these parameters were sought in regression analysis, and intra- and inter-subject variability was evaluated. RESULTS In 3,788 h of available data from 47 infants at 31 (28-33) post-menstrual weeks [median (interquartile range)], we identified 993 unique FiO2 adjustments followed by a first-order SpO2 response. All response parameters differed between FiO2 increments and decrements, with increments having a shorter delay, longer time constant and higher gain [2.9 (1.7-4.8) vs. 1.3 (0.58-2.6), p < 0.05]. Gain was also higher in less mature infants and in the setting of recent SpO2 instability, and was diminished with increasing severity of lung dysfunction. Intra-subject variability in all parameters was prominent. CONCLUSIONS First-order SpO2 responses show variable gain, influenced by the direction of FiO2 adjustment and the severity of lung disease, as well as substantial intra-subject parameter variability. These findings should be taken into account in adjustment of FiO2 for SpO2 targeting in preterm infants.
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Lim K, Wheeler KI, Jackson HD, Sadeghi Fathabadi O, Gale TJ, Dargaville PA. Lost without trace: oximetry signal dropout in preterm infants. Arch Dis Child Fetal Neonatal Ed 2015; 100:F436-8. [PMID: 26054970 DOI: 10.1136/archdischild-2014-308108] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 05/12/2015] [Indexed: 11/04/2022]
Abstract
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.
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Wheeler KI, Abdel-Latif ME, Davis PG, De Paoli AG, Dargaville PA. Surfactant therapy via brief tracheal catheterization in preterm infants with or at risk of respiratory distress syndrome. Hippokratia 2015. [DOI: 10.1002/14651858.cd011672] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Dargaville PA, Lavizzari A, Padoin P, Black D, Zonneveld E, Perkins E, Sourial M, Rajapaksa AE, Davis PG, Hooper SB, Moss TJ, Polglase GR, Tingay DG. An authentic animal model of the very preterm infant on nasal continuous positive airway pressure. Intensive Care Med Exp 2015. [PMID: 26215815 PMCID: PMC4512986 DOI: 10.1186/s40635-015-0051-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The surge in uptake of nasal continuous positive airway pressure (CPAP) for respiratory support in preterm infants has occurred in the absence of an authentic animal model. Such a model would allow investigation of research questions of physiological and therapeutic importance. We therefore aimed to develop a preterm lamb model of the non-intubated very preterm infant on CPAP. METHODS After staged exteriorisation and instrumentation, preterm lambs were delivered from anaesthetised ewes at 131 to 133 days gestation. Via a single nasal prong (4-mm internal diameter, 6- to 7-cm depth), positive pressure was delivered from the outset, with nasal intermittent positive pressure ventilation (NIPPV) used until transition to nasal CPAP was attempted, and periodically thereafter for hypoventilation. Caffeine and doxapram were used as respiratory stimulants. Gastric distension was prevented with an oesophageal balloon. Cardiorespiratory parameters and results of arterial blood gas analyses were monitored throughout the study period, which continued for 150 min after first transition to CPAP. RESULTS Ten preterm lambs were studied, at gestation 132 ± 1 days (mean ± SD) and birth weight 3.6 ± 0.45 kg. After stabilisation on NIPPV, transition to nasal CPAP was first attempted at 28 ± 11 min. There was transient respiratory acidosis, with gradual resolution as spontaneous respiratory activity increased. In the final hour, 79% ± 33% of time was spent on CPAP alone, with typical respiratory rates around 60 breaths per minute. PaCO2 at end-experiment was 58 ± 36 mmHg. CONCLUSIONS Non-intubated preterm lambs can be effectively transitioned to nasal CPAP soon after birth. This animal model will be valuable for further research.
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Tingay DG, John J, Harcourt ER, Black D, Dargaville PA, Mills JF, Davis PG. Are All Oscillators Created Equal? In vitro Performance Characteristics of Eight High-Frequency Oscillatory Ventilators. Neonatology 2015; 108:220-8. [PMID: 26304262 DOI: 10.1159/000431216] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Accepted: 05/07/2015] [Indexed: 11/19/2022]
Abstract
BACKGROUND The mode of waveform generation and circuit characteristics differ between high-frequency oscillators. It is unknown if this influences performance. OBJECTIVES To describe the relationships between set and delivered pressure amplitude (x0394;P), and the interaction with frequency and endotracheal tube (ETT) diameter, in eight high-frequency oscillators. METHODS Oscillators were evaluated using a 70-ml test lung at 1.0 and 2.0 ml/cm H2O compliance, with mean airway pressures (PAW) of 10 and 20 cm H2O, frequencies of 5, 10 and 15 Hz, and an ETT diameter of 2.5 and 3.5 mm. At each permutation of PAW, frequency and ETT, the set x0394;P was sequentially increased from 15 to 50 cm H2O, or from 20 to 100% maximum amplitude (10% increments) depending on the oscillator design. The x0394;P at the ventilator (x0394;PVENT), airway opening (x0394;PAO) and within the test lung (x0394;PTRACH), and tidal volume (V(T)) at the airway opening were determined at each set x0394;P. RESULTS In two oscillators the relationships between set and delivered x0394;P were non-linear, with a plateau in x0394;P thresholds noted at all frequencies (Dräger Babylog 8000) or ≥10 Hz (Dräger VN500). In all other devices there was a linear relationship between x0394;PVENT, x0394;PAO and x0394;PTRACH (all r2 >0.93), with differing attenuation of the pressure wave. Delivered V(T) at the different settings tested varied between devices, with some unable to deliver V(T) >3 ml at 15 Hz, and others generating V(T)>20 ml at 5 Hz and a 1:1 inspiratory-to-expiratory time ratio. CONCLUSIONS Clinicians should be aware that modern high-frequency oscillators exhibit important differences in the delivered x0394;P and V(T).
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El Shahed AI, Dargaville PA, Ohlsson A, Soll R. Surfactant for meconium aspiration syndrome in term and late preterm infants. Cochrane Database Syst Rev 2014; 2014:CD002054. [PMID: 25504256 PMCID: PMC7027383 DOI: 10.1002/14651858.cd002054.pub3] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND Surfactant replacement therapy has been proven beneficial in the prevention and treatment of neonatal respiratory distress syndrome (RDS). The deficiency of surfactant or surfactant dysfunction may contribute to respiratory failure in a broader group of disorders, including meconium aspiration syndrome (MAS). OBJECTIVES To evaluate the effect of surfactant administration in the treatment of late preterm and term infants with meconium aspiration syndrome. SEARCH METHODS We searched The Cochrane Library (Issue 4, 2006), MEDLINE and EMBASE (1985 to December 2006), previous reviews including cross-references, abstracts, conference and symposia proceedings, expert informants, and journal handsearching, without language restrictions. We contacted study authors for additional data.We ran an updated search in November 2014 and searched the following sites for ongoing or recently completed trials: www.clinicaltrials.gov; www.controlled-trials.com; and www.who.int/ictrp. SELECTION CRITERIA Randomised controlled trials which evaluated the effect of surfactant administration in late preterm and term infants with meconium aspiration syndrome are included in the analyses. DATA COLLECTION AND ANALYSIS We extracted data on clinical outcomes including mortality, treatment with extracorporeal membrane oxygenation (ECMO), pneumothorax, duration of assisted ventilation, duration of supplemental oxygen, intraventricular haemorrhage (any grade and severe IVH), and chronic lung disease. We conducted data analyses in accordance with the standards of the Cochrane Neonatal Review Group. MAIN RESULTS Four randomised controlled trials met our inclusion criteria. The meta-analysis of four trials (326 infants) showed no statistically significant effect on mortality [typical risk ratio (RR) 0.98, 95% confidence interval (CI) 0.41 to 2.39; typical risk difference (RD) -0.00, 95% CI -0.05 to 0.05]. There was no heterogeneity for this outcome (I² = 0% for both RR and RD). The risk of requiring extracorporeal membrane oxygenation was significantly reduced in a meta-analysis of two trials (n = 208); [typical RR 0.64, 95% CI 0.46 to 0.91; typical RD -0.17, 95% CI -0.30 to -0.04; number needed to treat for an additional beneficial outcome (NNTB) 6, 95% CI 3 to 25]. There was no heterogeneity for RR (1² = 0%) but moderate heterogeneity for RD (I² = 50%). One trial (n = 40) reported a statistically significant reduction in the length of hospital stay (mean difference -8 days, 95% CI -14 to -3 days; test for heterogeneity not applicable). There were no statistically significant reductions in any other outcomes studied (duration of assisted ventilation, duration of supplemental oxygen, pneumothorax, pulmonary interstitial emphysema, air leaks, chronic lung disease, need for oxygen at discharge or intraventricular haemorrhage). AUTHORS' CONCLUSIONS In infants with MAS, surfactant administration may reduce the severity of respiratory illness and decrease the number of infants with progressive respiratory failure requiring support with ECMO. The relative efficacy of surfactant therapy compared to, or in conjunction with, other approaches to treatment including inhaled nitric oxide, liquid ventilation, surfactant lavage and high frequency ventilation remains to be tested.
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Aguar M, Nuñez A, Cubells E, Cernada M, Dargaville PA, Vento M. Administration of surfactant using less invasive techniques as a part of a non-aggressive paradigm towards preterm infants. Early Hum Dev 2014; 90 Suppl 2:S57-9. [PMID: 25220131 DOI: 10.1016/s0378-3782(14)50015-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Traditional treatment of respiratory distress syndrome in preterm infants consisted of early intubation, mechanical ventilation and intra-tracheal administration of exogenous surfactant. Recently, non-invasive ventilation, which has shown some advantages in short- and long-term outcomes, has gained popularity for the initial management of respiratory insufficiency in preterm infants. However, non-invasive ventilation from the outset poses difficulties in relation to administration of exogenous surfactant. The customary INSURE technique requires tracheal intubation, surfactant administration, and rapid extubation, but the latter is not always possible. As a more elegant approach, several minimally invasive techniques of delivering surfactant have been developed for babies spontaneously breathing on CPAP. The most extensively studied have been those in which the trachea is briefly catheterized with a nasogastric tube or vascular catheter, and exogenous surfactant is administered. Although results seem promising they are not yet conclusive, and further studies will be needed to answer a number of outstanding questions.
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Dargaville PA, Kamlin COF, De Paoli AG, Carlin JB, Orsini F, Soll RF, Davis PG. The OPTIMIST-A trial: evaluation of minimally-invasive surfactant therapy in preterm infants 25-28 weeks gestation. BMC Pediatr 2014; 14:213. [PMID: 25164872 PMCID: PMC4236682 DOI: 10.1186/1471-2431-14-213] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Accepted: 08/12/2014] [Indexed: 11/23/2022] Open
Abstract
Background It is now recognized that preterm infants ≤28 weeks gestation can be effectively supported from the outset with nasal continuous positive airway pressure. However, this form of respiratory therapy may fail to adequately support those infants with significant surfactant deficiency, with the result that intubation and delayed surfactant therapy are then required. Infants following this path are known to have a higher risk of adverse outcomes, including death, bronchopulmonary dysplasia and other morbidities. In an effort to circumvent this problem, techniques of minimally-invasive surfactant therapy have been developed, in which exogenous surfactant is administered to a spontaneously breathing infant who can then remain on continuous positive airway pressure. A method of surfactant delivery using a semi-rigid surfactant instillation catheter briefly passed into the trachea (the “Hobart method”) has been shown to be feasible and potentially effective, and now requires evaluation in a randomised controlled trial. Methods/design This is a multicentre, randomised, masked, controlled trial in preterm infants 25–28 weeks gestation. Infants are eligible if managed on continuous positive airway pressure without prior intubation, and requiring FiO2 ≥ 0.30 at an age ≤6 hours. Randomisation will be to receive exogenous surfactant (200 mg/kg poractant alfa) via the Hobart method, or sham treatment. Infants in both groups will thereafter remain on continuous positive airway pressure unless intubation criteria are reached (FiO2 ≥ 0.45, unremitting apnoea or persistent acidosis). Primary outcome is the composite of death or physiological bronchopulmonary dysplasia, with secondary outcomes including incidence of death; major neonatal morbidities; durations of all modes of respiratory support and hospitalisation; safety of the Hobart method; and outcome at 2 years. A total of 606 infants will be enrolled. The trial will be conducted in >30 centres worldwide, and is expected to be completed by end-2017. Discussion Minimally-invasive surfactant therapy has the potential to ease the burden of respiratory morbidity in preterm infants. The trial will provide definitive evidence on the effectiveness of this approach in the care of preterm infants born at 25–28 weeks gestation. Trial registration Australia and New Zealand Clinical Trial Registry: ACTRN12611000916943; ClinicalTrials.gov: NCT02140580.
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Fathabadi OS, Gale TJ, Lim K, Salmon BP, Wheeler KI, Olivier JC, Dargaville PA. Assessment of validity and predictability of the FiO2–SpO2transfer-function in preterm infants. Physiol Meas 2014; 35:1425-37. [DOI: 10.1088/0967-3334/35/7/1425] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Lim K, Wheeler KI, Gale TJ, Jackson HD, Kihlstrand JF, Sand C, Dawson JA, Dargaville PA. Oxygen saturation targeting in preterm infants receiving continuous positive airway pressure. J Pediatr 2014; 164:730-736.e1. [PMID: 24433828 DOI: 10.1016/j.jpeds.2013.11.072] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Revised: 10/30/2013] [Accepted: 11/27/2013] [Indexed: 12/20/2022]
Abstract
OBJECTIVE The precision of oxygen saturation (SpO2) targeting in preterm infants on continuous positive airway pressure (CPAP) is incompletely characterized. We therefore evaluated SpO2 targeting in infants solely receiving CPAP, aiming to describe their SpO2 profile, to document the frequency of prolonged hyperoxia and hypoxia episodes and of fraction of inspired oxygen (FiO2) adjustments, and to explore the relationships with neonatal intensive care unit operational factors. STUDY DESIGN Preterm infants <37 weeks' gestation in 2 neonatal intensive care units were studied if they were receiving CPAP and in supplemental oxygen at the beginning of each 24-hour recording. SpO2, heart rate, and FiO2 were recorded (sampling interval 1-2 seconds). We measured the proportion of time spent in predefined SpO2 ranges, the frequency of prolonged episodes (≥30 seconds) of SpO2 deviation, and the effect of operational factors including nurse-patient ratio. RESULTS A total of 4034 usable hours of data were recorded from 45 infants of gestation 30 (27-32) weeks (median [IQR]). When requiring supplemental oxygen, infants were in the target SpO2 range (88%-92%) for only 31% (19%-39%) of total recording time, with 48 (6.9-90) episodes per 24 hours of severe hyperoxia (SpO2 ≥98%), and 9.0 (1.6-21) episodes per 24 hours of hypoxia (SpO2 <80%). An increased frequency of prolonged hyperoxia in supplemental oxygen was noted when nurses were each caring for more patients. Adjustments to FiO2 were made 25 (16-41) times per day. CONCLUSION SpO2 targeting is challenging in preterm infants receiving CPAP support, with a high proportion of time spent outside the target range and frequent prolonged hypoxic and hyperoxic episodes.
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Zannin E, Ventura ML, Dellacà RL, Natile M, Tagliabue P, Perkins EJ, Sourial M, Bhatia R, Dargaville PA, Tingay DG. Optimal mean airway pressure during high-frequency oscillatory ventilation determined by measurement of respiratory system reactance. Pediatr Res 2014; 75:493-9. [PMID: 24375086 DOI: 10.1038/pr.2013.251] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Accepted: 09/24/2013] [Indexed: 11/09/2022]
Abstract
BACKGROUND 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). METHODS 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. RESULTS 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. CONCLUSION X RS has the potential as a bedside tool for optimizing PAW during HFOV.
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Frerichs I, Dargaville PA, Rimensberger PC. Regional respiratory inflation and deflation pressure–volume curves determined by electrical impedance tomography. Physiol Meas 2013; 34:567-77. [DOI: 10.1088/0967-3334/34/6/567] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Abstract
BACKGROUND Meconium aspiration syndrome (MAS) can occur when a newborn infant inhales a mixture of meconium and amniotic fluid into the lungs around the time of delivery. Other than supportive measures, little effective therapy is available. Lung lavage may be a potentially effective treatment for MAS by virtue of removing meconium from the airspaces and altering the natural course of the disease. OBJECTIVES To evaluate the effects of lung lavage on morbidity and mortality in newborn infants with MAS. SEARCH METHODS We searched the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library), MEDLINE, and EMBASE up to December 2012; previous reviews including cross-references, abstracts, and conference proceedings; and expert informants. We contacted authors directly to obtain additional data. We used the following subject headings and text words: meconium aspiration, pulmonary surfactants, fluorocarbons, bronchoalveolar lavage, lung lavage, pulmonary lavage. SELECTION CRITERIA Randomised controlled trials that evaluated the effects of lung lavage in infants with MAS, including those intubated for the purpose of lavage. Lung lavage was defined as any intervention in which fluid is instilled into the lung that is followed by an attempt to remove it by suctioning and/or postural drainage. DATA COLLECTION AND ANALYSIS The review authors extracted from the reports of the clinical trial, data regarding clinical outcomes, including mortality, requirement for extracorporeal membrane oxygenation (ECMO), pneumothorax, duration of mechanical ventilation and oxygen therapy, length of hospital stay, indices of pulmonary function, and adverse effects of lavage. Data analysis was done in accordance with the standards of the Cochrane Neonatal Review Group. MAIN RESULTS Only four small randomised controlled trials fulfilled the selection criteria. For one of these trials, no data are available for the control group. Two studies compared lavage using diluted surfactant with standard care. Meta-analysis of these two studies did not show a significant effect on mortality (typical relative risk 0.42, 95% confidence interval [CI] 0.12 to 1.46; typical risk difference -0.10, 95% CI -0.24 to 0.04) or the use of ECMO (typical relative risk 0.27, 95% CI 0.04 to 1.86; typical risk difference -0.15, 95% CI -0.35 to 0.04). For the composite outcome of death or use of ECMO, a significant effect favoured the lavage group (typical relative risk 0.33, 95% CI 0.11 to 0.96; typical risk difference -0.19, 95% CI -0.34 to -0.03; number needed to benefit [NNTB] 5). No other benefits were reported. The other published study compared surfactant lavage followed by a surfactant bolus with surfactant bolus therapy alone in MAS complicated by pulmonary hypertension. No significant improvements in mortality, pneumothorax, duration of mechanical ventilation. or duration of hospitalisation were observed. AUTHORS' CONCLUSIONS In infants with meconium aspiration syndrome, lung lavage with diluted surfactant may be beneficial, but additional controlled clinical trials of lavage therapy should be conducted to confirm the treatment effect, to refine the method of lavage treatment, and to compare lavage treatment with other approaches, including surfactant bolus therapy. Long-term outcomes should be evaluated in further clinical trials.
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Dargaville PA, Aiyappan A, De Paoli AG, Kuschel CA, Kamlin COF, Carlin JB, Davis PG. Minimally-invasive surfactant therapy in preterm infants on continuous positive airway pressure. Arch Dis Child Fetal Neonatal Ed 2013; 98:F122-6. [PMID: 22684154 DOI: 10.1136/archdischild-2011-301314] [Citation(s) in RCA: 125] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVE To evaluate the applicability and potential effectiveness of a technique of minimally-invasive surfactant therapy (MIST) in preterm infants on continuous positive airway pressure (CPAP). METHODS An open feasibility study of MIST was conducted at two sites. Infants were eligible for MIST if needing CPAP pressure ≥7 cm H(2)O and FiO(2) ≥0.3 (25-28 weeks gestation, n=38) or ≥0.35 (29-32 weeks, n=23). Without premedication, a narrow-bore catheter was inserted through the vocal cords under direct vision. Surfactant (100 or 200 mg/kg Curosurf) was then instilled, followed by reinstitution of CPAP. Outcomes were compared between surfactant-treated infants and historical controls achieving the same CPAP and FiO(2) thresholds. RESULTS Surfactant was successfully administered via MIST in all cases, with a rapid and sustained reduction in FiO(2) thereafter. For infants at 25-28 weeks gestation, need for intubation <72 h was diminished after MIST compared with controls (32% vs 68%; OR 0.21, 95% CI 0.083 to 0.55), with a similar trend at 29-32 weeks (22% vs 45%; OR 0.34, 95% CI 0.11 to 1.1). Duration of ventilation and incidence of bronchopulmonary dysplasia were similar, but infants receiving MIST had a shorter duration of oxygen therapy. CONCLUSION Surfactant delivery via a narrow-bore tracheal catheter is feasible and potentially effective, and deserves further investigation in clinical trials.
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Dargaville PA, Copnell B, Mills JF, Haron I, Lee JKF, Tingay DG, Rohana J, Mildenhall LF, Jeng MJ, Narayanan A, Battin MR, Kuschel CA, Sadowsky JL, Patel H, Kilburn CJ, Carlin JB, Morley CJ. Fluid recovery during lung lavage in meconium aspiration syndrome. Acta Paediatr 2013. [PMID: 23194445 DOI: 10.1111/apa.12070] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
UNLABELLED Lung lavage using two aliquots of 15 mL/kg of dilute surfactant was performed in 30 ventilated infants with severe meconium aspiration syndrome (MAS). Mean recovery of instilled lavage fluid was 46%, with greater fluid return associated with lower mean airway pressure at 24 h and a shorter duration of respiratory support. CONCLUSION Recovery of instilled lavage fluid is paramount in effective lung lavage in MAS and must be afforded priority in the lavage technique.
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Dargaville PA, Aiyappan A, De Paoli AG, Dalton RGB, Kuschel CA, Kamlin CO, Orsini F, Carlin JB, Davis PG. Continuous positive airway pressure failure in preterm infants: incidence, predictors and consequences. Neonatology 2013; 104:8-14. [PMID: 23595061 DOI: 10.1159/000346460] [Citation(s) in RCA: 121] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Accepted: 12/13/2012] [Indexed: 11/19/2022]
Abstract
BACKGROUND Preterm infants ≤32 weeks' gestation are increasingly being managed on continuous positive airway pressure (CPAP), without prior intubation and surfactant therapy. Some infants treated in this way ultimately fail on CPAP and require intubation and ventilation. OBJECTIVES To define the incidence, predictors and consequences of CPAP failure in preterm infants managed with CPAP from the outset. METHODS Preterm infants 25-32 weeks' gestation were included in the study if inborn and managed with CPAP as the initial respiratory support, with division into two gestation ranges and grouping according to whether they were successfully managed on CPAP (CPAP-S) or failed on CPAP and required intubation <72 h (CPAP-F). Predictors of CPAP failure were sought, and outcomes compared between the groups. RESULTS 297 infants received CPAP, of which 65 (22%) failed, with CPAP failure being more likely at lower gestational age. Most infants failing CPAP had moderate or severe respiratory distress syndrome radiologically. In multivariate analysis, CPAP failure was found to be predicted by the highest FiO₂ in the first hours of life. CPAP-F infants had a prolonged need for respiratory support and oxygen therapy, and a higher risk of death or bronchopulmonary dysplasia at 25-28 weeks' gestation (CPAP-F 53% vs. CPAP-S 14%, relative risk 3.8, 95% CI 1.6, 9.3) and a substantially higher risk of pneumothorax at 29-32 weeks. CONCLUSION CPAP failure in preterm infants usually occurs because of unremitting respiratory distress syndrome, is predicted by an FiO₂ ≥0.3 in the first hours of life, and is associated with adverse outcomes.
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Squires KAG, De Paoli AG, Williams C, Dargaville PA. High-frequency oscillatory ventilation with low oscillatory frequency in pulmonary interstitial emphysema. Neonatology 2013; 104:243-9. [PMID: 24060678 DOI: 10.1159/000353376] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Accepted: 05/28/2013] [Indexed: 11/19/2022]
Abstract
BACKGROUND Pulmonary interstitial emphysema (PIE) is a common respiratory illness in preterm infants associated with significant morbidity and mortality for which the ventilatory management is imperfect. OBJECTIVES To evaluate the impact of high-frequency oscillatory ventilation (HFOV) with a low oscillatory frequency and thus prolonged expiratory time in preterm infants with severe PIE. METHODS In a retrospective cohort study, preterm infants ≤30 weeks' gestation with radiological findings of severe PIE, and either high FiO2 or persistent respiratory acidosis were studied if managed on HFOV with a low frequency (5-6 Hz, inspiratory time 30%) for >24 h. Trends in physiological and ventilatory parameters were examined over the first 72 h, radiological changes noted, and in-hospital outcomes ascertained. RESULTS 19 cases were identified and analysed in two groups: 14 with bilateral and 5 with predominantly unilateral disease. After transition to low-frequency HFOV, physiological responses were seen in both groups, in particular a rapid and sustained improvement in oxygenation in the bilateral group (mean (SD) alveolar-arterial oxygen difference at baseline: 404 ± 206 mm Hg; 4 h post-transition: 262 ± 181 mm Hg; 72 h: 155 ± 74 mm Hg; p = 0.0003). This occurred following a reduction in mean airway pressure (mean (SD) baseline: 14 ± 3.9 cm H2O; 72 h: 12 ± 2.9 cm H2O; p = 0.011). In the unilateral group, radiological resolution of PIE was observed on re-inflation following collapse of the affected lung. Overall, 15 infants survived, including 10 of the bilateral cases (71%), and all of the unilateral cases. CONCLUSION HFOV with a low oscillatory frequency may afford benefit in preterm babies with severe PIE.
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Abstract
The lungs of an extremely preterm infant ≤28 weeks gestation are structurally and biochemically immature and vulnerable to injury from positive pressure ventilation. A lung protective approach to respiratory support is vital, aiming to ventilate an open lung, using the lowest pressure settings that maintain recruitment and oxygenation and avoiding hyperinflation with each tidal breath. For infants with severe respiratory distress syndrome and persistent atelectasis, lung protective ventilation requires recruitment using stepwise pressure increments, followed by reduction in ventilator pressures in search of an optimal point at which to maintain ventilation. Several studies, including a single randomised controlled trial, have found this lung protective strategy to be more effectively administered using high-frequency oscillatory ventilation rather than conventional ventilation. Many extremely preterm infants have minimal atelectasis and low oxygen requirements in the first days of life, and the ventilatory approach in this case should be one of avoidance of factors including overdistension that are known to contribute to later pulmonary deterioration. From a practical perspective, this means setting positive end-expiratory pressure at the lowest value that maintains oxygenation and restricting tidal volume using a volume-targeted mode of ventilation.
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Dargaville PA. Innovation in surfactant therapy I: surfactant lavage and surfactant administration by fluid bolus using minimally invasive techniques. Neonatology 2012; 101:326-36. [PMID: 22940622 DOI: 10.1159/000337346] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Innovation in the field of exogenous surfactant therapy continues more than two decades after the drug became commercially available. One such innovation, lung lavage using dilute surfactant, has been investigated in both laboratory and clinical settings as a treatment for meconium aspiration syndrome (MAS). Studies in animal models of MAS have affirmed that dilute surfactant lavage can remove meconium from the lung, with resultant improvement in lung function. In human infants both non-randomised studies and two randomised controlled trials have demonstrated a potential benefit of dilute surfactant lavage over standard care. The largest clinical trial, performed by our research group in infants with severe MAS, found that lung lavage using two 15-ml/kg aliquots of dilute surfactant did not reduce the duration of respiratory support, but did appear to reduce the composite outcome of death or need for extracorporeal membrane oxygenation. A further trial of lavage therapy is planned to more precisely define the effect on survival. Innovative approaches to surfactant therapy have also extended to the preterm infant, for whom the more widespread use of continuous positive airway pressure (CPAP) has meant delaying or avoiding administration of surfactant. In an effort to circumvent this problem, less invasive techniques of bolus surfactant therapy have been trialled, including instillation directly into the pharynx, via laryngeal mask and via brief tracheal catheterisation. In a recent clinical trial, instillation of surfactant into the trachea using a flexible feeding tube was found to reduce the need for subsequent intubation. We have developed an alternative method of brief tracheal catheterisation in which surfactant is delivered via a semi-rigid vascular catheter inserted through the vocal cords under direct vision. In studies to date, this technique has been relatively easy to perform, and resulted in rapid improvement in lung function and reduced need for subsequent ventilation and duration of oxygen therapy. We are now commencing large-scale clinical trials of this method in preterm infants on CPAP.
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Dargaville PA, Aiyappan A, Cornelius A, Williams C, De Paoli AG. Preliminary evaluation of a new technique of minimally invasive surfactant therapy. Arch Dis Child Fetal Neonatal Ed 2011; 96:F243-8. [PMID: 20971722 DOI: 10.1136/adc.2010.192518] [Citation(s) in RCA: 129] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
OBJECTIVE To investigate a method of minimally invasive surfactant therapy (MIST) to be used in spontaneously breathing preterm infants on continuous positive airway pressure (CPAP), evaluating the feasibility of the technique and the therapeutic benefit after MIST. DESIGN Non-randomised feasibility study. SETTING Tertiary neonatal intensive care unit. PATIENTS AND INTERVENTIONS Study subjects were preterm infants with respiratory distress supported with CPAP, with early enrolment of 25-28-week infants (n=11) at any CPAP pressure and fractional inspired O(2) concentration (FiO(2)), and enrolment of 29-34-week infants (n=14) at CPAP pressure ≥7 cm H(2)O and FiO(2) ≥0.35. Without premedication, a 16 gauge vascular catheter was inserted through the vocal cords under direct vision. Porcine surfactant (~100 mg/kg) was then instilled, followed by reinstitution of CPAP. MEASUREMENTS AND RESULTS Respiratory indices were documented for 4 h following MIST, and neonatal outcomes ascertained. In all cases, surfactant was successfully administered and CPAP re-established. Coughing (32%) and bradycardia (44%) were transiently noted, and 44% received positive pressure inflations. There was a clear surfactant effect, with lower FiO(2) after MIST (pre-MIST: 0.39±0.092 (mean±SD); 4 h: 0.26±0.093; p<0.01), and a modest reduction in CPAP pressure. Adverse outcomes were few: intubation within 72 h (n=3), pneumothorax (n=1), chronic lung disease (n=3) and death (n=1), all in the 25-28-week group. Outcome was otherwise favourable in both gestation groups, with a trend towards reduction in intubation in the first 72 h in the 25-28-week infants compared with historical controls. CONCLUSIONS Surfactant can be effectively delivered via a vascular catheter, and this method of MIST deserves further investigation.
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Dargaville PA, Copnell B, Mills JF, Haron I, Lee JKF, Tingay DG, Rohana J, Mildenhall LF, Jeng MJ, Narayanan A, Battin MR, Kuschel CA, Sadowsky JL, Patel H, Kilburn CJ, Carlin JB, Morley CJ. Randomized controlled trial of lung lavage with dilute surfactant for meconium aspiration syndrome. J Pediatr 2011; 158:383-389.e2. [PMID: 20947097 DOI: 10.1016/j.jpeds.2010.08.044] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2010] [Revised: 07/13/2010] [Accepted: 08/25/2010] [Indexed: 11/15/2022]
Abstract
OBJECTIVE To evaluate whether lung lavage with surfactant changes the duration of mechanical respiratory support or other outcomes in meconium aspiration syndrome (MAS). STUDY DESIGN We conducted a randomized controlled trial that enrolled ventilated infants with MAS. Infants randomized to lavage received two 15-mL/kg aliquots of dilute bovine surfactant instilled into, and recovered from, the lung. Control subjects received standard care, which in both groups included high frequency ventilation, nitric oxide, and, where available, extracorporeal membrane oxygenation (ECMO). RESULTS Sixty-six infants were randomized, with one ineligible infant excluded from analysis. Median duration of respiratory support was similar in infants who underwent lavage and control subjects (5.5 versus 6.0 days, P = .77). Requirement for high frequency ventilation and nitric oxide did not differ between the groups. Fewer infants who underwent lavage died or required ECMO: 10% (3/30) compared with 31% (11/35) in the control group (odds ratio, 0.24; 95% confidence interval, 0.060-0.97). Lavage transiently reduced oxygen saturation without substantial heart rate or blood pressure alterations. Mean airway pressure was more rapidly weaned in the lavage group after randomization. CONCLUSION Lung lavage with dilute surfactant does not alter duration of respiratory support, but may reduce mortality, especially in units not offering ECMO.
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Kiraly NJ, Tingay DG, Mills JF, Dargaville PA, Copnell B. Volume not guaranteed: closed endotracheal suction compromises ventilation in volume-targeted mode. Neonatology 2011; 99:78-82. [PMID: 20733330 DOI: 10.1159/000316854] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2009] [Accepted: 06/08/2010] [Indexed: 11/19/2022]
Abstract
BACKGROUND Closed endotracheal suction interferes with mechanical ventilation received by infants, but the change to ventilation may be different when ventilator modes that target expired tidal volume (VT(e)) are used. OBJECTIVE To measure airway pressure and tidal volume distal to the endotracheal tube (ETT) during and after closed suction in a volume-targeted ventilation mode with the Dräger Babylog 8000+, and to determine the time until VT(e) returns to the baseline level. METHODS In this benchtop study, closed suction was performed on 2.5- to 4.0-mm ETTs connected to a test lung. 5-8 French suction catheters were used at suction pressures of 80-200 mm Hg during tidal-volume-targeted ventilation. RESULTS During catheter insertion and suction, circuit inflating pressure increased and tidal volume was maintained, except when a large catheter relative to the ETT was used, in which case tidal volume decreased. End-expiratory pressure distal to the ETT was reduced during suction by up to 75 cm H(2)O while circuit end-expiratory pressure was unchanged. Reduction in end-expiratory pressure distal to the ETT was greatest with large catheters and high suction pressures. Following suction, circuit and tracheal inflating pressures increased and tidal volume increased before returning to baseline in 8-12 s. CONCLUSIONS Closed endotracheal suction interferes with ventilator function in volume-targeted mode, with substantially negative intratracheal pressure during suction, and the potential for high airway pressures and tidal volumes following the procedure. These effects should be considered and pressure limits set appropriately whenever using volume-targeted ventilation.
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Dargaville PA, Rimensberger PC. Lung volume measurement in the neonate-throwing light on the subject: commentary on the article by Dellaca' et al. on page 11. Pediatr Res 2010; 67:9-10. [PMID: 20010379 DOI: 10.1203/pdr.0b013e3181c9170d] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Kiraly NJ, Tingay DG, Mills JF, Morley CJ, Dargaville PA, Copnell B. The effects of closed endotracheal suction on ventilation during conventional and high-frequency oscillatory ventilation. Pediatr Res 2009; 66:400-4. [PMID: 19581839 DOI: 10.1203/pdr.0b013e3181b337ec] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
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.
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Copnell B, Dargaville PA, Ryan EM, Kiraly NJ, Chin LOF, Mills JF, Tingay DG. The effect of suction method, catheter size, and suction pressure on lung volume changes during endotracheal suction in piglets. Pediatr Res 2009; 66:405-10. [PMID: 19581841 DOI: 10.1203/pdr.0b013e3181b337b9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
We aimed to identify the effect of suction pressure and catheter size on change in lung volume during open and closed endotracheal suction. Anesthetized piglets (n = 12) were intubated with a 4.0-mm endotracheal tube. Lung injury was induced with saline lavage. Three suction methods (open, closed in-line, and closed with a side-port adaptor) were performed in random order using 6, 7, and 8 French gauge (FG) catheters, at vacuum pressures of 80, 140, and 200 mm Hg. Lung volume change was measured with respiratory inductive plethysmography. Overall, open suction resulted in greater lung volume loss during and at 60-s postsuction than either closed method (p < 0.001). When open and closed methods were analyzed separately, volume change was independent of catheter size and suction pressure with open suction. With closed suction, volume loss increased with larger catheter sizes and higher suction pressures (p < 0.001). With an 8-FG catheter and suction pressure of 140 or 200 mm Hg, volume loss was equivalent with open and closed suction. Lung volume changes are influenced by catheter size and suction pressure, as well as suction method. With commonly used suction pressures and catheter sizes, closed suction has no advantage in preventing loss of volume in this animal model.
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Hoellering AB, Copnell B, Dargaville PA, Mills JF, Morley CJ, Tingay DG. Lung volume and cardiorespiratory changes during open and closed endotracheal suction in ventilated newborn infants. Arch Dis Child Fetal Neonatal Ed 2008; 93:F436-41. [PMID: 18305069 DOI: 10.1136/adc.2007.132076] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
OBJECTIVES To compare change in lung volume (DeltaV(L)), using respiratory inductive plethysmography, time to recover pre-suction lung volume (t(rec)) and the cardiorespiratory disturbances associated with open suction (OS) and closed suction (CS) in ventilated infants. DESIGN Randomised blinded crossover trial. SETTING Neonatal intensive care unit. PATIENTS Thirty neonates, 20 receiving synchronised intermittent mandatory ventilation (SIMV) and 10 high-frequency oscillatory ventilation (HFOV, four receiving muscle relaxant). INTERVENTIONS OS and CS were performed, in random order, on each infant using a 6FG catheter at -19 kPa for 6 seconds and repeated after 1 minute. OUTCOME MEASURES DeltaV(L), oxygen saturation (Spo(2)) and heart rate were continuously recorded from 2 minutes before until 5 minutes after suction. Lowest values were identified during the 60 seconds after suction. RESULTS Variations in all measures were seen during CS and OS. During SIMV no differences were found between OS and CS for maximum DeltaV(L) or t(rec); mean (95% CI) difference of 3.5 ml/kg (-2.8 to 9.7) and 4 seconds (-5 to 13), respectively. During HFOV t(rec) was longer during OS by 13 seconds (0 to 27) but there was no difference in the maximum DeltaV(L) of 0.1 mV (-0.02 to 0.22). A small reduction in SpO(2) with CS in the SIMV group mean difference 6% (2.1 to 9.8) was the only significant difference in physiological measurements. CONCLUSIONS Both OS and CS produced transient variable reductions in heart rate and Spo(2). During SIMV there was no difference between OS and CS in DeltaV(L) or t(rec). During HFOV there was no difference in DeltaV(L) but a slightly longer t(rec) after OS.
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McCallion N, Lau R, Morley CJ, Dargaville PA. Neonatal volume guarantee ventilation: effects of spontaneous breathing, triggered and untriggered inflations. Arch Dis Child Fetal Neonatal Ed 2008; 93:F36-9. [PMID: 17686798 DOI: 10.1136/adc.2007.126284] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND During volume guarantee (VG) ventilation the peak inflating pressure (PIP) for each ventilator inflation is adjusted to ensure the expired tidal volume (V(Te)) is close to the set V(Te). Differences in the PIP between inflations triggered by the infant's inspirations and untriggered inflations are seen. AIM To investigate the effects of triggered and untriggered inflations on PIP and V(Te). METHODS Neonates were ventilated with the Dräger Babylog 8000 using assist control (synchronous intermittent positive pressure ventilation) and VG modes. Continuous recordings of ventilator pressures and tidal volumes were made at 200 Hz for 10 minutes. RESULTS In 10 infants, 6540 inflations were analysed, of which 4052 (62%) were triggered. Triggered inflations had a significantly lower mean (SD) PIP than untriggered inflations: 12.9 (4.9) vs 17.0 (3.3) cm H2O, (p<0.001). Despite this, there was no significant difference in the V(Te) of each type of inflation (103% and 101% of the set V(Te), respectively). When a triggered inflation was immediately preceded or followed by an untriggered inflation the PIP changed by about 5 cm H2O. Between adjacent inflations of the same type, the change in PIP was less than 3 cm H2O: for triggered inflations it was 0.11 (1.50) cm H2O and for untriggered inflations 0.06 (1.53) cm H2O. CONCLUSION During VG ventilation with the Dräger Babylog 8000 the PIP was 4 cm H2O lower during triggered inflations than untriggered inflations, although the expired tidal volumes were similar.
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Dargaville PA, Copnell B, Tingay DG, Gordon MJ, Mills JF, Morley CJ. Refining the method of therapeutic lung lavage in meconium aspiration syndrome. Neonatology 2008; 94:160-3. [PMID: 18612212 DOI: 10.1159/000143394] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2007] [Accepted: 11/07/2007] [Indexed: 11/19/2022]
Abstract
BACKGROUND Therapeutic lung lavage is an emerging treatment for meconium aspiration syndrome (MAS), but the ideal fluid volume and lavage technique remain unclear. OBJECTIVE To evaluate the impact of suction technique, chest squeeze and aliquot volume on the efficacy of lung lavage in MAS. METHODS 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. RESULTS 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 < 0.01). CONCLUSIONS 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.
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Dargaville PA, Mills JF, Copnell B, Loughnan PM, McDougall PN, Morley CJ. Therapeutic lung lavage in meconium aspiration syndrome: a preliminary report. J Paediatr Child Health 2007; 43:539-45. [PMID: 17635682 DOI: 10.1111/j.1440-1754.2007.01130.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
AIM To explore the effects of a large volume lung lavage procedure in ventilated infants with meconium aspiration syndrome. METHODS Infants with severe meconium aspiration requiring high-frequency ventilation underwent lung lavage using dilute bovine surfactant at a phospholipid concentration of 5 mg/mL. Lavage aliquot volumes were increased through the case series, aiming to deliver two aliquots of 15 mL/kg in rapid sequence. Physiological effects of lavage were documented, and comparison was made with a group of infants with meconium aspiration requiring high-frequency ventilation, in whom lavage was not performed. RESULTS Nine episodes of lavage were performed in eight infants at a median age of 23 h (range 8-83 h). Three infants underwent a lavage that was defined as potentially therapeutic (total lavage volume of at least 25 mL/kg administered before 24 h of age). Lavage was not associated with bradycardia or hypotension. Recovery of arterial oxygen saturation to above 80% was achieved within 12 min in all but one infant in whom oxygen saturation was below 80% at the outset. Mean airway pressure was significantly lower in the Therapeutic lavage group compared with non-lavaged infants in the first 48 h, with a trend towards improved oxygenation. CONCLUSION Dilute surfactant lavage with aliquots of up to 15 mL/kg appears to be feasible in haemodynamically stable ventilated infants with meconium aspiration syndrome, and its efficacy deserves further investigation in a randomised controlled trial.
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Crossley KJ, Morley CJ, Allison BJ, Polglase GR, Dargaville PA, Harding R, Hooper SB. Blood gases and pulmonary blood flow during resuscitation of very preterm lambs treated with antenatal betamethasone and/or Curosurf: effect of positive end-expiratory pressure. Pediatr Res 2007; 62:37-42. [PMID: 17515834 DOI: 10.1203/pdr.0b013e31806790ed] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
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.
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Copnell B, Tingay DG, Kiraly NJ, Sourial M, Gordon MJ, Mills JF, Morley CJ, Dargaville PA. A comparison of the effectiveness of open and closed endotracheal suction. Intensive Care Med 2007; 33:1655-62. [PMID: 17492268 DOI: 10.1007/s00134-007-0635-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2006] [Accepted: 03/26/2007] [Indexed: 10/23/2022]
Abstract
OBJECTIVE To compare the effectiveness of open and closed endotracheal suction in recovering thin and thick secretions in normal and injured lungs during conventional and high frequency ventilation. DESIGN AND SETTING Randomised study in a paediatric intensive care model in the animal research laboratory of a tertiary paediatric hospital. SUBJECTS 16 New Zealand White rabbits. INTERVENTIONS Anaesthetised animals were intubated with a 3.5-mm endotracheal tube. Simulated thin and thick secretions (iopamidol 2 ml, a watery radio-opaque fluid, and fluorescent mucin 1 ml) were instilled in turn 1 cm below the tube tip through a catheter placed via a tracheostomy. Open or closed suction, randomly assigned, was applied for 6s at -140 mmHg using a 6-F gauge catheter. Following lung injury with repeated saline lavage the procedure was repeated on conventional and high frequency ventilation. MEASUREMENTS AND RESULTS Iopamidol recovery was determined by digitally subtracting the post-contrast and post-suction radiographic images. Mucin recovery was determined by fluorescence assay of the aspirate. In the normal lung similar amounts were recovered by both suction methods. In the lavaged lung closed suction recovered less iopamidol during conventional (22 +/- 7.5%) and high frequency ventilation (11 +/- 2.4%) than open suction (36 +/- 2% and 22 +/- 8.1%, respectively). Mucin recovery was less with closed suction during conventional 32 +/- 28 microl) and high frequency ventilation (30 +/- 31 microl) than with open suction (382 +/- 235 microl and 24 +/- 153 microl). CONCLUSIONS In the injured lung closed suction was less effective than open suction at recovering thin and thick simulated secretions, irrespective of ventilation mode.
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De Paoli AG, Williams M, Parsons SJ, Long E, Brothers L, Dargaville PA. Massive hepatic congenital haemangioma: clinical dilemmas. J Paediatr Child Health 2007; 43:312-4. [PMID: 17444837 DOI: 10.1111/j.1440-1754.2007.01066.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
A case of massive hepatomegaly secondary to a hepatic congenital haemangioma in a preterm neonate is described. This infant died after withdrawal of neonatal intensive care support, following massive intracerebral haemorrhage. There remains considerable uncertainty regarding the classification of, and therapy for, hepatic vascular anomalies.
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Tingay DG, Mills JF, Morley CJ, Pellicano A, Dargaville PA. Trends in use and outcome of newborn infants treated with high frequency ventilation in Australia and New Zealand, 1996-2003. J Paediatr Child Health 2007; 43:160-6. [PMID: 17316190 DOI: 10.1111/j.1440-1754.2007.01036.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
AIM To examine the use of high frequency ventilation (HFV) to treat newborn infants in Australia and New Zealand and the associated complications and outcomes. METHODS Data for all infants receiving HFV were collected from the 28 neonatal intensive care units contributing to the Australian and New Zealand Neonatal Network database between 1996 and 2003, inclusive. For comparison, the same data were gathered on all infants who received conventional mechanical ventilation (CMV) and nasal continuous positive airway pressure. RESULTS HFV was used to treat 3270 infants (10.1% of all ventilated infants) between 1996 and 2003; uptake doubled during this period from 5.9% to 12.6% of ventilated infants per year. HFV was most frequently applied in the context of extreme prematurity (29.9% of ventilated infants <26 weeks gestation). HFV is being increasingly used to treat complex diseases such as meconium aspiration syndrome and congenital diaphragmatic hernia (12.2% and 10.6% in 1996 to 25.2% and 48.4% in 2003, respectively, chi2 -test for trend, P<0.001). Infants receiving HFV spent longer on respiratory support than infants treated with CMV (median 21 days compared with 7 days, Mann-Whitney test P<0.001) and required a higher initial FiO2 (median 0.8 compared to 0.5, Mann-Whitney test, P<0.001). The use of HFV was associated with a higher mortality than CMV and nasal continuous positive airway pressure (39.7%, 10.1% and 0.4%, chi2 -test, P<0.001). The incidence of death and intraventricular haemorrhage decreased over time in the HFV group (chi2 -test for trend, P<0.001 and P=0.02 respectively). CONCLUSION HFV is an established mode of neonatal ventilation in Australia and New Zealand. HFV is being applied to infants at the greatest risk of serious adverse outcomes, most likely as a rescue therapy.
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Tingay DG, Copnell B, Mills JF, Morley CJ, Dargaville PA. Effects of open endotracheal suction on lung volume in infants receiving HFOV. Intensive Care Med 2007; 33:689-93. [PMID: 17333119 DOI: 10.1007/s00134-007-0541-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2006] [Accepted: 01/11/2007] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To describe the pattern and magnitude of lung volume change during open endotracheal tube (ETT) suction in infants receiving high-frequency oscillatory ventilation (HFOV). DESIGN Prospective observational clinical study. SETTING Tertiary neonatal intensive care unit. PATIENTS AND PARTICIPANTS Seven intubated and muscle-relaxed newborn infants receiving HFOV. INTERVENTIONS Open ETT suction was performed for 6 s at -100 mmHg using a 6-F catheter passed to the ETT tip after disconnection from HFOV. The HFOV was then recommenced at the same settings as prior to ETT suction. MEASUREMENTS AND RESULTS Change in lung volume (DeltaV (L)) referenced to baseline lung volume before suction was measured with a calibrated respiratory inductive plethysmography recording from 30 s before until 60 s after ETT suction. In all infants ETT suction resulted in significant loss of lung volume. The mean DeltaV (L) during suctioning was -13 ml/kg (SD 4 ml/kg) (p<0.0001 vs. baseline, repeated-measures ANOVA), with a mean 76.5% (SD 14.1%) of this volume loss being related to circuit disconnection. After recommencing HFOV lung volume was rapidly regained with mean DeltaV (L) at 60 s being 1 ml/kg (SD 4 ml/kg) below baseline (p>0.05, Tukey post-test). CONCLUSIONS Open ETT suction caused a significant but transient loss of lung volume in muscle-relaxed newborn infants receiving HFOV.
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Frerichs I, Dargaville PA, van Genderingen H, Morel DR, Rimensberger PC. Lung Volume Recruitment after Surfactant Administration Modifies Spatial Distribution of Ventilation. Am J Respir Crit Care Med 2006; 174:772-9. [PMID: 16840739 DOI: 10.1164/rccm.200512-1942oc] [Citation(s) in RCA: 139] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Although surfactant replacement therapy is an established treatment in infant respiratory distress syndrome, the optimum strategy for ventilatory management before, during, and after surfactant instillation remains to be elucidated. OBJECTIVES To determine the effects of surfactant and lung volume recruitment on the distribution of regional lung ventilation. METHODS Acute lung injury was induced in 16 newborn piglets by endotracheal lavage. Optimum positive end-expiratory pressure was identified after lung recruitment and surfactant was administered either at this pressure in the "open" lung or after disconnection of the endotracheal tube in the "closed" lung. An additional recruitment maneuver with subsequent optimum end-expiratory pressure finding was executed in eight animals; in the remaining eight animals, end-expiratory pressure was set at the same level as before surfactant without further recruitment. ("Open" and "closed" lung surfactant administration was evenly distributed in the groups.) Regional ventilation was assessed by electrical impedance tomography. MEASUREMENTS AND MAIN RESULTS Impedance tomography data, airway pressure, flow, and arterial blood gases were acquired during baseline conditions, after induction of lung injury, after the first lung recruitment, and before as well as 10 and 60 min after surfactant administration. Significant shift in ventilation toward the dependent lung regions and less asymmetry in the right-to-left lung ventilation distribution occurred in the postsurfactant period when an additional recruitment maneuver was performed. Surfactant instillation in an "open" versus "closed" lung did not influence ventilation distribution in a major way. CONCLUSIONS The spatial distribution of ventilation in the lavaged lung is modified by a recruitment maneuver performed after surfactant administration.
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Tingay DG, Mills JF, Morley CJ, Pellicano A, Dargaville PA. Oxygenation as an Indicator for the Optimal Lung Volume in Ventilated Newborn Infants: Useful or Useless? Am J Respir Crit Care Med 2006. [DOI: 10.1164/ajrccm.174.2.229a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Wilkinson DJ, Fitzsimons JJ, Dargaville PA, Campbell NT, Loughnan PM, McDougall PN, Mills JF. Death in the neonatal intensive care unit: changing patterns of end of life care over two decades. Arch Dis Child Fetal Neonatal Ed 2006; 91:F268-71. [PMID: 16790729 PMCID: PMC2672727 DOI: 10.1136/adc.2005.074971] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Death remains a common event in the neonatal intensive care unit, and often involves limitation or withdrawal of life sustaining treatment. OBJECTIVE To document changes in the causes of death and its management over the last two decades. METHODS An audit of infants dying in the neonatal intensive care unit was performed during two epochs (1985-1987 and 1999-2001). The principal diagnoses of infants who died were recorded, as well as their apparent prognoses, and any decisions to limit or withdraw medical treatment. RESULTS In epoch 1, 132 infants died out of 1362 admissions (9.7%), and in epoch 2 there were 111 deaths out of 1776 admissions (6.2%; p<0.001). Approximately three quarters of infants died after withdrawal of life sustaining treatment in both epochs. There was a significant reduction in the proportion of deaths from chromosomal abnormalities, and from neural tube defects in epoch 2. CONCLUSIONS There have been substantial changes in the illnesses leading to death in the neonatal intensive care unit. These may reflect the combined effects of prenatal diagnosis and changing community and medical attitudes.
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Wong FY, Mitchell PJ, Tress BM, Dargaville PA, Loughnan PM. Hemodynamic disturbances associated with endovascular embolization in newborn infants with vein of Galen malformation. J Perinatol 2006; 26:273-8. [PMID: 16554851 DOI: 10.1038/sj.jp.7211479] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE To examine hemodynamic changes following endovascular embolization in newborn infants with vein of Galen malformation and severe cardiac failure in the first week of life. STUDY DESIGN Over a recent 5-year period, nine such infants were identified. In seven of these infants, changes in arterial blood pressure were analyzed in relation to the timing of embolization procedures. RESULTS A significant increase in arterial blood pressure was noted after most embolizations. In two infants, this systemic hypertension was severe and treated using intravenous antihypertensive drugs. Both infants subsequently developed complete infarction of both cerebral hemispheres with sparing of the brainstem and cerebellum. Mortality in the nine infants was 33%, and 83% of the survivors were neurologically normal or near normal at follow-up. CONCLUSION The systemic hypertension observed following endovascular embolizations may provide a protective mechanism to maintain cerebral blood flow after reperfusion injury. Lowering blood pressure in this situation may therefore be detrimental.
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Dargaville PA, Copnell B. The epidemiology of meconium aspiration syndrome: incidence, risk factors, therapies, and outcome. Pediatrics 2006; 117:1712-21. [PMID: 16651329 DOI: 10.1542/peds.2005-2215] [Citation(s) in RCA: 196] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE 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). DESIGN 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. RESULTS 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 >50% of infants receiving > 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). CONCLUSIONS 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.
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Tingay DG, Mills JF, Morley CJ, Pellicano A, Dargaville PA. The Deflation Limb of the Pressure–Volume Relationship in Infants during High-Frequency Ventilation. Am J Respir Crit Care Med 2006; 173:414-20. [PMID: 16322649 DOI: 10.1164/rccm.200502-299oc] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE The importance of applying high-frequency oscillatory ventilation with a high lung volume strategy in infants is well established. Currently, a lack of reliable methods for assessing lung volume limits clinicians' ability to achieve the optimum volume range. OBJECTIVES To map the pressure-volume relationship of the lung during high-frequency oscillatory ventilation in infants, to determine at what point ventilation is being applied clinically, and to describe the relationship between airway pressure, lung volume, and oxygenation. METHODS In 12 infants, a partial inflation limb and the deflation limb of the pressure-volume relationship were mapped using a quasi-static lung volume optimization maneuver. This involved stepwise airway pressure increments to total lung capacity, followed by decrements until the closing pressure of the lung was identified. MEASUREMENTS AND MAIN RESULTS Lung volume and oxygen saturation were recorded at each airway pressure. Lung volume was measured using respiratory inductive plethysmography. A distinct deflation limb could be mapped in each infant. Overall, oxygenation and lung volume were improved by applying ventilation on the deflation limb. Maximal lung volume and oxygenation occurred on the deflation limb at a mean airway pressure of 3 and 5 cm H(2)O below the airway pressure approximating total lung capacity, respectively. CONCLUSIONS Using current ventilation strategies, all infants were being ventilated near the inflation limb. It is possible to delineate the deflation limb in infants receiving high-frequency oscillatory ventilation; in doing so, greater lung volume and oxygenation can be achieved, often at lower airway pressures.
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Probyn ME, Hooper SB, Dargaville PA, McCallion N, Harding R, Morley CJ. Effects of tidal volume and positive end-expiratory pressure during resuscitation of very premature lambs. Acta Paediatr 2005; 94:1764-70. [PMID: 16421037 DOI: 10.1111/j.1651-2227.2005.tb01851.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Guidelines recommend neonatal resuscitation without controlling tidal volume or positive end-expiratory pressure (PEEP). However, these may improve gas exchange, lung volume and outcome. AIM To investigate resuscitation of very premature lambs with a Laerdal bag without PEEP versus volume guarantee ventilation with PEEP. METHODS Anaesthetized lambs (n=20) delivered at 125 d gestation were randomized to three groups receiving 15 min resuscitation: (1) Laerdal bag and no PEEP; (2) ventilation with a tidal volume of 5 ml/kg and 8 cm H(2)O PEEP; (3) ventilation with 10 ml/kg and 8 cm H(2)O PEEP. They were then all ventilated for 2 h with tidal volumes of 5 or 10 ml/kg, and 8 cm H(2)O PEEP. Ventilation parameters and blood gases were recorded. RESULTS Different tidal volumes affected PaCO(2) within minutes, with 10 ml/kg causing severe hypocarbia. PEEP had little effect on PaCO(2). Oxygenation improved significantly with PEEP of 8 cm H(2)O, irrespective of tidal volume. CONCLUSION Very premature lambs can be resuscitated effectively using volume-guarantee ventilation and PEEP. Tidal volumes affected PaCO(2) within minutes but had little effect on oxygenation. PEEP halved the oxygen requirement compared with no PEEP. Resuscitating premature babies with controlled tidal volumes and PEEP might improve their outcome.
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O'Donnell CPF, Davis PG, Lau R, Dargaville PA, Doyle LW, Morley CJ. Neonatal resuscitation 2: an evaluation of manual ventilation devices and face masks. Arch Dis Child Fetal Neonatal Ed 2005; 90:F392-6. [PMID: 15871989 PMCID: PMC1721950 DOI: 10.1136/adc.2004.064691] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND The key to successful neonatal resuscitation is effective ventilation. Little evidence exists to guide clinicians in their choice of manual ventilation device or face mask. 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 compare the efficacy of (a) the Laerdal infant resuscitator and the Neopuff infant resuscitator, used with (b) round and anatomically shaped masks in a model of neonatal resuscitation. METHODS Thirty four participants gave positive pressure ventilation to a mannequin at specified pressures with each of the four device-mask combinations. Flow, inspiratory tidal volume at the face mask (V(TI(mask))), V(TE(mask)), and airway pressure were recorded. Leakage from the mask was calculated from V(TI(mask)) and V(TE(mask)). RESULTS A total of 10,780 inflations were recorded and analysed. Peak inspiratory pressure targets were achieved equally with the Laerdal and Neopuff resuscitators. Positive end expiratory pressure was delivered with the Neopuff but not the Laerdal device. Despite similar peak pressures, V(TE(mask)) varied widely. Mask leakage was large for each combination of device and mask. There were no differences between the masks. CONCLUSION During face mask ventilation of a neonatal resuscitation mannequin, there are large leaks around the face mask. Airway pressure is a poor proxy for volume delivered during positive pressure ventilation through a mask.
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