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Abduljalil K, Pan X, Pansari A, Jamei M, Johnson TN. A Preterm Physiologically Based Pharmacokinetic Model. Part I: Physiological Parameters and Model Building. Clin Pharmacokinet 2021; 59:485-500. [PMID: 31583613 DOI: 10.1007/s40262-019-00825-6] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
BACKGROUND Developmental physiology can alter pharmacotherapy in preterm populations. Because of ethical and clinical constraints in studying this vulnerable age group, physiologically based pharmacokinetic models offer a viable alternative approach to predicting drug pharmacokinetics and pharmacodynamics in this population. However, such models require comprehensive information on the changes of anatomical, physiological and biochemical variables, where such data are not available in a single source. OBJECTIVE The objective of this study was to integrate the relevant physiological parameters required to build a physiologically based pharmacokinetic model for the preterm population. METHODS Published information on developmental preterm physiology and some drug-metabolising enzymes were collated and analysed. Equations were generated to describe the changes in parameter values during growth. RESULTS Data on organ size show different growth patterns that were quantified as functions of bodyweight to retain physiological variability and correlation. Protein binding data were quantified as functions of age as the body weight was not reported in the original articles. Ontogeny functions were derived for cytochrome P450 1A2, 3A4 and 2C9. Tissue composition values and how they change with age are limited. CONCLUSIONS Despite the limitations identified in the availability of some tissue composition values, the data presented in this article provide an integrated resource of system parameters needed for building a preterm physiologically based pharmacokinetic model.
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Affiliation(s)
- Khaled Abduljalil
- Simcyp Division Level 2-Acero, Certara UK Limited, 1 Concourse Way, Sheffield, S1 2BJ, UK.
| | - Xian Pan
- Simcyp Division Level 2-Acero, Certara UK Limited, 1 Concourse Way, Sheffield, S1 2BJ, UK
| | - Amita Pansari
- Simcyp Division Level 2-Acero, Certara UK Limited, 1 Concourse Way, Sheffield, S1 2BJ, UK
| | - Masoud Jamei
- Simcyp Division Level 2-Acero, Certara UK Limited, 1 Concourse Way, Sheffield, S1 2BJ, UK
| | - Trevor N Johnson
- Simcyp Division Level 2-Acero, Certara UK Limited, 1 Concourse Way, Sheffield, S1 2BJ, UK
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Ericksen K, Alpan G, La Gamma EF. Effect of ventilator modes on neonatal cerebral and peripheral oxygenation using near-infrared spectroscopy. Acta Paediatr 2021; 110:1151-1156. [PMID: 32989810 DOI: 10.1111/apa.15600] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 08/27/2020] [Accepted: 09/23/2020] [Indexed: 12/01/2022]
Abstract
AIM The effect of ventilator modes on regional tissue oxygenation in premature neonates with respiratory distress syndrome (RDS) has yet to be delineated. Previous studies have looked at global oxygen delivery and have not assessed the effects on regional tissue oxygenation. Our aim in this study was to assess such tissue oxygenation in premature babies with RDS in relation to differing modes of ventilation using near-infrared spectroscopy (NIRS). METHODS In 24 stable preterm infants with RDS, undergoing elective wean in ventilator mode, cerebral and muscle tissue oxygenation were assessed using NIRS. Infants were weaned from high-frequency oscillator or jet ventilator to conventional invasive ventilation (CV) or extubated from CV to non-invasive mechanical ventilation. Data at 30 minutes prior and at one hour after change in ventilator mode were compared (paired t test). RESULTS In babies changed from high-frequency oscillation to CV, jet to CV and CV to non-invasive ventilation, the differences in cerebral NIRS (mean ± SD) were 1.7 ± 9.9%, 2.3 ± 5.7% and 2.1 ± 8.4%, respectively. The concomitant changes in muscle NIRS were -2.9 ± 8.5%, 8.1 ± 9.7% and 3.6 ± 22.4%, respectively. No changes were statistically significant. CONCLUSION Our data suggest that there is no alteration in regional tissue oxygenation related to ventilator mode in stable preterm infants with improving RDS.
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Affiliation(s)
- Kristina Ericksen
- Division of Perinatal‐Neonatal Medicine Maria Fareri Children’s Hospital at Westchester Medical Center New York Medical College Valhalla, New York NY USA
| | - Gad Alpan
- Division of Perinatal‐Neonatal Medicine Maria Fareri Children’s Hospital at Westchester Medical Center New York Medical College Valhalla, New York NY USA
| | - Edmund F. La Gamma
- Division of Perinatal‐Neonatal Medicine Maria Fareri Children’s Hospital at Westchester Medical Center New York Medical College Valhalla, New York NY USA
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Chattopadhyay A, Gupta S, Sankar J, Kabra SK, Lodha R. Outcomes of Severe PARDS on High-Frequency Oscillatory Ventilation - A Single Centre Experience. Indian J Pediatr 2020; 87:185-191. [PMID: 31925715 PMCID: PMC7222899 DOI: 10.1007/s12098-019-03134-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2019] [Accepted: 11/19/2019] [Indexed: 12/04/2022]
Abstract
OBJECTIVE To describe experience with high-frequency oscillatory ventilation (HFOV) in children with acute respiratory distress syndrome (ARDS) transitioned from conventional mechanical ventilation (CMV) due to refractory hypoxemia and to assess factors associated with survival and also compare outcomes of patients who were managed with early HFOV (within 24 h of intubation) vs. late HFOV. METHODS This retrospective, observational study was conducted in a tertiary care hospital's pediatric intensive care unit. Thirty-four children with pediatric acute respiratory distress syndrome (PARDS) managed with HFOV were included. RESULTS Of 34 children with PARDS managed with HFOV after failure of conventional ventilation to improve oxygenation, 8 survived. Improvement in the Oxygenation Index (OI) at 48 h of initiation of HFOV along with percent increase in PaO2/FiO2 (P/F ratio) at 24 h of HFOV were predictors of survival. The response to HFOV, based on OI and P/F ratio, between 24 and 48 h of ventilation identified potential survivors. Also, lower positive end-expiratory pressure (PEEP) on CMV and shorter duration of CMV before initiation of HFOV were associated with survival. CONCLUSIONS Survival in pediatric ARDS patients treated with HFOV could be predicted by using trends of OI - with survivors showing a more rapid decline in OI between 24 and 48 h of initiation compared to non-survivors.
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Affiliation(s)
- Arpita Chattopadhyay
- Division of Pediatric Pulmonology and Intensive Care, Department of Pediatrics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India
| | - Samriti Gupta
- Division of Pediatric Pulmonology and Intensive Care, Department of Pediatrics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India
| | - Jhuma Sankar
- Division of Pediatric Pulmonology and Intensive Care, Department of Pediatrics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India
| | - Sushil K Kabra
- Division of Pediatric Pulmonology and Intensive Care, Department of Pediatrics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India
| | - Rakesh Lodha
- Division of Pediatric Pulmonology and Intensive Care, Department of Pediatrics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India.
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Hupp SR, Turner DA, Rehder KJ. Is there still a role for high-frequency oscillatory ventilation in neonates, children and adults? Expert Rev Respir Med 2015; 9:603-18. [PMID: 26290121 DOI: 10.1586/17476348.2015.1077119] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Critically ill patients with respiratory pathology often require mechanical ventilation and while low tidal volume ventilation has become the mainstay of treatment, achieving adequate gas exchange may not be attainable with conventional ventilator modalities. In attempt to achieve gas exchange goals and also mitigate lung injury, high frequency ventilation is often implemented which couples low tidal volumes with sustained mean airway pressure. This manuscript presents the physiology of high-frequency oscillatory ventilation, reviews the currently available data on its use and provides strategies and approaches for this mode of ventilation.
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Affiliation(s)
| | - David A Turner
- a Division of Pediatric Critical Care Medicine, Department of Pediatrics, Duke University Medical Center, Durham, North Carolina, USA
| | - Kyle J Rehder
- a Division of Pediatric Critical Care Medicine, Department of Pediatrics, Duke University Medical Center, Durham, North Carolina, USA
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Cools F, Offringa M, Askie LM. Elective high frequency oscillatory ventilation versus conventional ventilation for acute pulmonary dysfunction in preterm infants. Cochrane Database Syst Rev 2015; 2015:CD000104. [PMID: 25785789 PMCID: PMC10711725 DOI: 10.1002/14651858.cd000104.pub4] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Respiratory failure due to lung immaturity is a major cause of mortality in preterm infants. Although the use of intermittent positive pressure ventilation (IPPV) in neonates with respiratory failure saves lives, its use is associated with lung injury and chronic lung disease. A newer form of ventilation called high frequency oscillatory ventilation has been shown in experimental studies to result in less lung injury. OBJECTIVES The objective of this review was to determine the effect of the elective use of high frequency oscillatory ventilation (HFOV) as compared to conventional ventilation (CV) on the incidence of chronic lung disease (CLD), mortality and other complications associated with prematurity and assisted ventilation in preterm infants who were mechanically ventilated for respiratory distress syndrome (RDS). SEARCH METHODS Searches were made of the Oxford Database of Perinatal Trials, MEDLINE, EMBASE, previous reviews including cross references, abstracts, conference and symposia proceedings; and from expert informants and handsearching of journals by The Cochrane Collaboration, mainly in the English language. The search was updated in January 2009 and again in November 2014. SELECTION CRITERIA Randomised controlled trials comparing HFOV and CV in preterm or low birth weight infants with pulmonary dysfunction, mainly due to RDS, who required assisted ventilation. Randomisation and commencement of treatment needed to be as soon as possible after the start of CV and usually in the first 12 hours of life. DATA COLLECTION AND ANALYSIS The methodological quality of each trial was independently reviewed by the review authors. The standard effect measures were relative risk (RR) and risk difference (RD). From 1/RD the number needed to benefit (NNTB) to produce one outcome was calculated. For all measures of effect, 95% confidence intervals (CIs) were used. For interpretation of subgroup analyses, a P value for subgroup differences as well as the I(2) statistic for between-subgroup heterogeneity were calculated. Meta-analysis was performed using both a fixed-effect and a random-effects model. Where heterogeneity was over 50%, the random-effects model RR was also reported. MAIN RESULTS Nineteen eligible studies involving 4096 infants were included. Meta-analysis comparing HFOV with CV revealed no evidence of effect on mortality at 28 to 30 days of age or at approximately term equivalent age. These results were consistent across studies and in subgroup analyses. The risk of CLD in survivors at term equivalent gestational age was significantly reduced with the use of HFOV but this effect was inconsistent across studies, even after the meta-analysis was restricted to studies that applied a high lung volume strategy with HFOV. Subgroup analysis by HFOV strategy showed a similar effect in trials with a more strict lung volume recruitment strategy, targeting a very low fraction of inspired oxygen (FiO2), and trials with a less strict lung volume recruitment strategy and with a somewhat higher or unspecified target FiO2. Subgroup analyses by age at randomisation, routine surfactant use or not, type of high frequency ventilator (oscillator versus flow interrupter), inspiratory to expiratory (I:E) ratio of high frequency ventilator (1:1 versus 1:2) and CV strategy (lung protective or not) could not sufficiently explain the heterogeneity. Pulmonary air leaks, defined as gross air leaks or pulmonary interstitial emphysema, occurred more frequently in the HFOV group, whereas the risk of severe retinopathy of prematurity was significantly reduced.Although in some studies an increased risk of severe grade intracranial haemorrhage and periventricular leukomalacia was found, the overall meta-analysis revealed no significant differences in effect between HFOV and CV. The short-term neurological morbidity with HFOV was only found in the subgroup of two trials not using a high volume strategy with HFOV. Most trials did not find a significant difference in long-term neurodevelopmental outcome, although one recent trial showed a significant reduction in the risk of cerebral palsy and poor mental development. AUTHORS' CONCLUSIONS There is evidence that the use of elective HFOV compared with CV results in a small reduction in the risk of CLD, but the evidence is weakened by the inconsistency of this effect across trials. Probably many factors, both related to the intervention itself as well as to the individual patient, interact in complex ways. In addition, the benefit could be counteracted by an increased risk of acute air leak. Adverse effects on short-term neurological outcomes have been observed in some studies but these effects are not significant overall. Most trials reporting long-term outcome have not identified any difference.
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Affiliation(s)
- Filip Cools
- CEBAM, Belgian Centre for Evidence‐Based MedicineKapucijnenvoer 33, blok J, bus 7001LeuvenBelgium3000
| | - Martin Offringa
- Hospital for Sick ChildrenChild Health Evaluative Sciences555 University AvenueTorontoONCanadaM5G 1X8
| | - Lisa M Askie
- University of SydneyNHMRC Clinical Trials CentreLocked Bag 77CamperdownNSWAustralia2050
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Bojan M, Gioanni S, Mauriat P, Pouard P. High-frequency oscillatory ventilation and short-term outcome in neonates and infants undergoing cardiac surgery: a propensity score analysis. Crit Care 2011; 15:R259. [PMID: 22035562 PMCID: PMC3334810 DOI: 10.1186/cc10521] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2011] [Revised: 08/24/2011] [Accepted: 10/28/2011] [Indexed: 11/10/2022] Open
Abstract
INTRODUCTION Experience with high-frequency oscillatory ventilation (HFOV) after congenital cardiac surgery is limited despite evidence about reduction in pulmonary vascular resistance after the Fontan procedure. HFOV is recommended in adults and children with acute respiratory distress syndrome. The aim of the present study was to assess associations between commencement of HFOV on the day of surgery and length of mechanical ventilation, length of Intensive Care Unit (ICU) stay and mortality in neonates and infants with respiratory distress following cardiac surgery. METHODS A logistic regression model was used to develop a propensity score, which accounted for the probability of being switched from conventional mechanical ventilation (CMV) to HFOV on the day of surgery. It included baseline characteristics, type of procedure and postoperative variables, and was used to match each patient with HFOV with a control patient, in whom CMV was used exclusively. Length of mechanical ventilation, ICU stay and mortality rates were compared in the matched set. RESULTS Overall, 3,549 neonates and infants underwent cardiac surgery from January 2001 through June 2010, 120 patients were switched to HFOV and matched with 120 controls. After adjustment for the delay to sternal closure, duration of renal replacement therapy, occurrence of pulmonary hypertension and year of surgery, the probability of successful weaning over time and the probability of ICU delivery over time were significantly higher in patients with HFOV, adjusted hazard ratios and 95% confidence intervals: 1.63, 1.17 to 2.26 (P = 0.004). and 1.65, 95% confidence intervals: 1.20 to 2.28 (P = 0.002) respectively. No association was found with mortality. CONCLUSIONS When commenced on the day of surgery in neonates and infants with respiratory distress following cardiac surgery, HFOV was associated with shorter lengths of mechanical ventilation and ICU stay than CMV.
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Affiliation(s)
- Mirela Bojan
- Anesthesiolgy and Critical Care Department, Necker-Enfants Malades Hospital, Assistance Publique-Hôpitaux de Paris, 149 rue de Sèvres, 75015 Paris, France
| | - Simone Gioanni
- Anesthesiolgy and Critical Care Department, Necker-Enfants Malades Hospital, Assistance Publique-Hôpitaux de Paris, 149 rue de Sèvres, 75015 Paris, France
| | - Philippe Mauriat
- Anesthesiolgy and Critical Care Department, Haut-Lévêque Hospital, 1 avenue de Magellan, 33604 Pessac, France
| | - Philippe Pouard
- Anesthesiolgy and Critical Care Department, Necker-Enfants Malades Hospital, Assistance Publique-Hôpitaux de Paris, 149 rue de Sèvres, 75015 Paris, France
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Kuluz MA, Smith PB, Mears SP, Benjamin JR, Tracy ET, Williford WL, Goldberg RN, Rice HE, Cotten CM. Preliminary observations of the use of high-frequency jet ventilation as rescue therapy in infants with congenital diaphragmatic hernia. J Pediatr Surg 2010; 45:698-702. [PMID: 20385273 PMCID: PMC3243761 DOI: 10.1016/j.jpedsurg.2009.07.025] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2009] [Revised: 07/06/2009] [Accepted: 07/06/2009] [Indexed: 10/19/2022]
Abstract
BACKGROUND/PURPOSE Congenital diaphragmatic hernia (CDH) is associated with mortality of 10% to 50%. Several investigators have reported outcomes from centers using high-frequency oscillatory ventilation in their management of CDH, but there are no recent reports on use of high-frequency jet ventilation. METHODS During the study period from January 2001 until August 2007, infants with CDH who were cared for at Duke University Medical Center received high-frequency jet ventilation as a rescue mode of high-frequency ventilation. We compared actual survival with predicted survival for infants treated only with conventional ventilation vs those rescued with high-frequency jet ventilation after failing conventional ventilation. RESULTS Survival for the 16 infants that received high-frequency jet ventilation was predicted to be 63%; actual survival was 75%. Survival for the 15 infants that received only conventional ventilation was predicted to be 83%; actual survival was 87%. We observed no significant survival benefit for high-frequency jet ventilation, 8.0% (95 confidence interval, -22.0% to 38.1%; P = .59). CONCLUSIONS Although our sample size was small, we conclude with consideration of the absolute results, the degree of illness of the infants, and the biologic plausibility for the intervention that high-frequency jet ventilation is an acceptable rescue ventilation mode for infants with CDH.
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Affiliation(s)
- Michael A. Kuluz
- Department of Pediatrics, Duke University, Durham, North Carolina
| | - P. Brian Smith
- Department of Pediatrics, Duke University, Durham, North Carolina,Duke University Clinical Research Institute, Durham, North Carolina
| | - Sarah P. Mears
- Department of Pediatrics, Duke University, Durham, North Carolina
| | | | | | - W. Lee Williford
- Department of Pediatrics, Duke University, Durham, North Carolina
| | | | - Henry E. Rice
- Department of Surgery, Duke University, Durham, North Carolina
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High-frequency oscillatory ventilation for acute respiratory distress syndrome. Indian J Pediatr 2009; 76:921-7. [PMID: 19475349 DOI: 10.1007/s12098-009-0151-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2008] [Accepted: 07/25/2008] [Indexed: 10/20/2022]
Abstract
OBJECTIVE To evaluate the effectiveness of HFOV in pediatric patients with acute respiratory distress syndrome. METHODS In this retrospective study, we reviewed all 20 pediatric patients, who were consecutively ventilated with HFOV in the pediatric intensive care unit of a tertiary medical center, from January 2006 to February 2007. RESULTS A total of 20 patients were enrolled. The median age of the subjects was 70 (3-168) months; 10 were male. All patients received conventional ventilation before HFOV. After initiation of HFOV, there was an immediate and sustained increase in PaO(2)/FiO(2) ratio. The PaO(2)/FiO(2) ratio was elevated and OI was decreased significantly after 10-20 minutes and maintained for at least 48 hours (p= 0.03, both). Thirteen of the 20 patients were successfully weaned. No significant change in the mean arterial pressure and heart rate was noted after HFOV. Overall survival rate was 65%. Of 20 patients, 11 patients suffered from extrapulmonary ARDS (ARDSexp) and 9 from pulmonary ARDS (ARDSp). When HFOV was initiated, there was significant increase in PaO(2)/FiO(2) and decrease in OI in ARDSexp compared to ARDSp (p= 0.03, both). Also mortality rate was significantly lower in patients with ARDSexp (9% vs.66%), (p= 0.01). CONCLUSION In our study, HFOV was effective in oxygenation and seems to be safe for pediatric ARDS patients. HFOV affected ARDSp and ARDSexp paediatric patients differently. However prospective, randomized controlled trials are needed to identify its benefits over conventional modes of mechanical ventilation.
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Cools F, Henderson-Smart DJ, Offringa M, Askie LM. Elective high frequency oscillatory ventilation versus conventional ventilation for acute pulmonary dysfunction in preterm infants. Cochrane Database Syst Rev 2009:CD000104. [PMID: 19588317 DOI: 10.1002/14651858.cd000104.pub3] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND Respiratory failure due to lung immaturity is a major cause of mortality in preterm infants. Although the use of intermittent positive pressure ventilation (IPPV) in neonates with respiratory failure saves lives, its use is associated with lung injury and chronic lung disease (CLD). A newer form of ventilation called high frequency oscillatory ventilation (HFOV) has been shown to result in less lung injury in experimental studies. OBJECTIVES The objective of this review is to determine the effect of the elective use of high frequency oscillatory ventilation (HFOV) as compared to conventional ventilation (CV) on the incidence of chronic lung disease, mortality and other complications associated with prematurity and assisted ventilation in preterm infants who are mechanically ventilated for respiratory distress syndrome (RDS). SEARCH STRATEGY Searches were made of the Oxford Database of Perinatal Trials, MEDLINE, EMBASE, previous reviews including cross references, abstracts, conferences and symposia proceedings, expert informants, journal hand searching by the Cochrane Collaboration, mainly in the English language. The search was updated in January 2009. SELECTION CRITERIA Randomised controlled trials comparing HFOV and CV in preterm or low birth weight infants with pulmonary dysfunction, mainly due to RDS, who required assisted ventilation. Randomisation and commencement of treatment needed to be as soon as possible after the start of CV and usually in the first 12 hours of life. DATA COLLECTION AND ANALYSIS The methodological quality of each trial was independently reviewed by the various authors. The standard effect measures are relative risk (RR) and risk difference (RD). From 1/RD the number needed to treat (NNT) to produce one outcome were calculated. For all measures of effect, 95% confidence intervals were used. In subgroup analyses the 99% CIs are also given for summary RRs in the text. Meta-analysis was performed using a fixed effects model. Where heterogeneity was over 50%, the random effects RR is also given. MAIN RESULTS Seventeen eligible studies of 3,652 infants were included. Meta-analysis comparing HFOV with CV revealed no evidence of effect on mortality at 28 - 30 days of age or at approximately term equivalent age. These results were consistent across studies and in subgroup analyses. The effect of HFOV on CLD in survivors at term equivalent gestational age was inconsistent across studies and the reduction was of borderline significance overall. The effect was similar in trials with a high lung volume strategy for HFOV targeting at very low FiO(2) and trials with a high lung volume strategy with somewhat higher or unspecified target FiO(2). Subgroups of trials showed a significant reduction in CLD with HFOV when no surfactant was used, when piston oscillators were used for HFOV, when lung protective strategies for CV were not used, when randomisation occurred at two to six hours of age, and when inspiratory:expiratory ratio of 1:2 was used for HFOV. In the meta-analysis of all trials, pulmonary air leaks occurred more frequently in the HFOV group.In some studies, short-term neurological morbidity with HFOV was found, but this effect was not statistically significant overall. The subgroup of two trials not using a high volume strategy with HFOV found increased rates of Grade 3 or 4 intraventricular haemorrhage and of periventricular leukomalacia. An adverse effect of HFOV on long-term neurodevelopment was found in one large trial but not in the five other trials that reported this outcome. The rate of retinopathy of prematurity is reduced overall in the HFOV group. AUTHORS' CONCLUSIONS There is no clear evidence that elective HFOV offers important advantages over CV when used as the initial ventilation strategy to treat preterm infants with acute pulmonary dysfunction. There may be a small reduction in the rate of CLD with HFOV use, but the evidence is weakened by the inconsistency of this effect across trials and the overall borderline significance. Future trials on elective HFOV should target those infants who are at most risk of CLD (extremely preterm infants), compare different strategies for generating HFOV and CV, and report important long-term neurodevelopmental outcomes.
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Affiliation(s)
- Filip Cools
- Neonatology, Universitair Ziekenhuis Brussel, Laarbeekaan 101, Brussels, Belgium, 1090
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The role of high frequency oscillatory ventilation in the management of children with severe traumatic brain injury and concomitant lung pathology. Pediatr Crit Care Med 2008; 9:e38-42. [PMID: 18779699 DOI: 10.1097/pcc.0b013e3181731ab7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE To report the use of high frequency oscillatory ventilation (HFOV) in two children with severe traumatic brain injury and concurrent lung pathology where conventional mechanical ventilation was ineffective. DESIGN : Case report. SETTING Regional intensive care unit in a pediatric teaching hospital. PATIENTS Two severely head-injured children (both with postresuscitation Glasgow Coma Scores of 3), one of whom was age 11 yrs and developed an invasive fungal (rhizomucor) pneumonia, while the other age 5 yrs had bilateral lung contusions. Both were treated according to local head injury guidelines, which included conventional ventilation. Despite increasing conventional ventilatory support, CO2 removal became problematic in both cases, making the intracranial pressure control and consequent maintenance of adequate cerebral perfusion pressure difficult. In both patients, a dramatic reduction in intracranial pressure and improvement in cerebral perfusion pressure was observed soon after the use of HFOV. Additionally, inotropic support was weaned by 50% in both children after commencing HFOV. A significant increase in the mean arterial blood pressure occurred in one child with HFOV. INTERVENTION Use of HFOV as an alternative to conventional mechanical ventilation. CONCLUSION HFOV may have utility in the management of selected cases of severe brain trauma with concurrent lung pathology where conventional ventilation is ineffective.
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Henderson-Smart DJ, Cools F, Bhuta T, Offringa M. Elective high frequency oscillatory ventilation versus conventional ventilation for acute pulmonary dysfunction in preterm infants. Cochrane Database Syst Rev 2007:CD000104. [PMID: 17636590 DOI: 10.1002/14651858.cd000104.pub2] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Respiratory failure due to lung immaturity is a major cause of mortality in preterm infants. Although the use of intermittent positive pressure ventilation (IPPV) in neonates with respiratory failure saves lives, its use is associated with lung injury and chronic lung disease (CLD). Conventional IPPV is provided at 30-80 breaths per minute, while a newer form of ventilation called high frequency oscillatory ventilation (HFOV) provides 'breaths' at 10 - 15 cycles per second. This has been shown to result in less lung injury in experimental studies. OBJECTIVES The objective of this review is to determine the effect of the elective use of high frequency oscillatory ventilation (HFOV) as compared to conventional ventilation (CV) in preterm infants who are mechanically ventilated for respiratory distress syndrome (RDS), on the incidence of chronic lung disease, mortality and other complications associated with prematurity and assisted ventilation. SEARCH STRATEGY Searches were made of the Oxford Database of Perinatal Trials, MEDLINE, EMBASE, previous reviews including cross references, abstracts, conferences and symposia proceedings, expert informants, journal hand searching by the Cochrane Collaboration, mainly in the English language. The search was updated in April 2007. SELECTION CRITERIA Randomised controlled trials comparing HFOV and CV in preterm or low birth weight infants with pulmonary dysfunction, mainly due to RDS, who were given IPPV. Randomisation and commencement of treatment needed to be as soon as possible after the start of IPPV and usually in the first 12 hours of life. DATA COLLECTION AND ANALYSIS The methodological quality of each trial was independently reviewed by the various authors. The standard effect measures are relative risk (RR) and risk difference (RD). From 1/RD the number needed to treat (NNT) to produce one outcome were calculated. For all measures of effect, 95% confidence intervals were used. In subgroup analyses the 99% CIs are also given for summary RRs in the text. Meta-analysis was performed using a fixed effects model. Where heterogeneity was over 50%, the random effects RR is also given. MAIN RESULTS Fifteen eligible studies of 3,585 infants were included. Meta-analysis comparing HFOV with CV revealed no evidence of effect on mortality at 28 - 30 days of age or at approximately term equivalent age. These results were consistent across studies and in subgroup analyses. The effect of HFOV on CLD in survivors at term equivalent gestational age was inconsistent across studies and the reduction was of borderline significance overall. Subgroups of trials showed a significant reduction in CLD with HFOV when high volume strategy for HFOV was used, when piston oscillators were used for HFOV, when lung protective strategies for CV were not used, when randomisation occurred at two to six hours of age, and when inspiratory:expiratory ratio of 1:2 was used for HFOV. In the meta-analysis of all trials, pulmonary air leaks occurred more frequently in the HFOV group. In some studies, short-term neurological morbidity with HFOV was found, but this effect was not statistically significant overall. The subgroup of two trials not using a high volume strategy with HFOV found increased rates of Grade 3 or 4 intraventricular haemorrhage and of periventricular leukomalacia. An adverse effect of HFOV on long-term neurodevelopment was found in one large trial but not in the five other trials that reported this outcome. The rate of retinopathy of prematurity is reduced overall in the HFOV group. AUTHORS' CONCLUSIONS There is no clear evidence that elective HFOV offers important advantages over CV when used as the initial ventilation strategy to treat preterm infants with acute pulmonary dysfunction. There may be a small reduction in the rate of CLD with HFOV use, but the evidence is weakened by the inconsistency of this effect across trials and the overall borderline significance. Future trials on elective HFOV should target those infants who are at most risk of CLD (extremely preterm infants), compare different strategies for generating HFOV and CV, and report important long-term neurodevelopmental outcomes.
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Affiliation(s)
- D J Henderson-Smart
- Queen Elizabeth II Research Institute, NSW Centre for Perinatal Health Services Research, Building DO2, University of Sydney, Sydney, NSW, Australia, 2006.
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Downar J, Mehta S. Bench-to-bedside review: high-frequency oscillatory ventilation in adults with acute respiratory distress syndrome. Crit Care 2007; 10:240. [PMID: 17184554 PMCID: PMC1794464 DOI: 10.1186/cc5096] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Mechanical ventilation is the cornerstone of therapy for patients with acute respiratory distress syndrome (ARDS). Paradoxically, mechanical ventilation can exacerbate lung damage – a phenomenon known as ventilator-induced lung injury. While new ventilation strategies have reduced the mortality rate in patients with ARDS, this mortality rate still remains high. High-frequency oscillatory ventilation (HFOV) is an unconventional form of ventilation that may improve oxygenation in patients with ARDS, while limiting further lung injury associated with high ventilatory pressures and volumes delivered during conventional ventilation. HFOV has been used for almost two decades in the neonatal population, but there is more limited experience with HFOV in the adult population. In adults, the majority of the published literature is in the form of small observational studies in which HFOV was used as 'rescue' therapy for patients with very severe ARDS who were failing conventional ventilation. Two prospective randomized controlled trials, however, while showing no mortality benefit, have suggested that HFOV, compared with conventional ventilation, is a safe and effective ventilation strategy for adults with ARDS. Several studies suggest that HFOV may improve outcomes if used early in the course of ARDS, or if used in certain populations. This review will summarize the evidence supporting the use of HFOV in adults with ARDS.
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Affiliation(s)
- James Downar
- Department of Medicine, Mount Sinai Hospital and University of Toronto, 600 University Avenue #18-216, Toronto, Ontario, Canada
| | - Sangeeta Mehta
- Department of Medicine, Mount Sinai Hospital and University of Toronto, 600 University Avenue #18-216, Toronto, Ontario, Canada
- Interdepartmental Division of Critical Care Medicine, Mount Sinai Hospital and University of Toronto, 600 University Avenue #18-216, Toronto, Ontario, Canada
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Victor S, Appleton RE, Beirne M, Marson AG, Weindling AM. The relationship between cardiac output, cerebral electrical activity, cerebral fractional oxygen extraction and peripheral blood flow in premature newborn infants. Pediatr Res 2006; 60:456-60. [PMID: 16940235 DOI: 10.1203/01.pdr.0000238379.67720.19] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Cardiac output is a determinant of systemic blood flow and its measurement may therefore be a useful indicator of abnormal hemodynamics and tissue oxygen delivery. The purpose of this study was to investigate in very premature newborn infants the relationships between cardiac output (left and right ventricular outputs), systemic blood pressure, peripheral blood flow (PBF) and two indicators of cerebral oxygen delivery (cerebral electrical activity and cerebral fractional oxygen extraction (CFOE)). This was a prospective observational study performed on 40 infants of less than 30 wk gestation. Digital electroencephalograms (EEGs) were recorded for one hour every day during the first four days after birth and subjected to qualitative and quantitative analysis. Left and right ventricular outputs, mean blood pressure (MBP), CFOE, PBF and arterial blood gases were measured at the same time. Within the ranges studied, there was no apparent relationship between left or right ventricular output (RVO), PBF and indicators of cerebral perfusion (cerebral electrical activity and CFOE). The EEG was normal in infants with low left and right ventricular outputs (<150 mL/kg/min) and MBP > 30 mm Hg. Infants with low cardiac output and normal MBP seem able to maintain cerebral perfusion, possibly through vasodilatation of the cerebral microvasculature.
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Affiliation(s)
- Suresh Victor
- Division of Child Health, University of Liverpool, Liverpool Women's Hospital, Liverpool, UK.
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Mehta S, Granton J, MacDonald RJ, Bowman D, Matte-Martyn A, Bachman T, Smith T, Stewart TE. High-Frequency Oscillatory Ventilation in Adults. Chest 2004. [DOI: 10.1016/s0012-3692(15)31165-x] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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15
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Gullberg N, Winberg P, Selldén H. Changes in mean airway pressure during HFOV influences cardiac output in neonates and infants. Acta Anaesthesiol Scand 2004; 48:218-23. [PMID: 14995945 DOI: 10.1111/j.1399-6576.2004.00299.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Changes in mean airway pressure affect cardiac output during conventional positive pressure ventilation. The effect of high-frequency oscillation ventilation (HFOV) on cardiac output is less studied. METHODS A prospective study in a university hospital pediatric intensive care unit. Fourteen patients aged <1 year and weighing <10 kg who were on HFOV were included. All patients had been on HFOV for >12 h and were considered to be in a stable condition. In the study group (n = 9) the mean proximal airway pressure (Paw) was increased and decreased by +5 and -3 cmH2O, respectively, from baseline in each patient. Measurements were made at each level including baseline settings between each change. In a control group (n = 5) no changes in ventilatory parameters were made. Cardiac output was assessed with echocardiography and the Doppler technique at each level of Paw and at similar intervals in the control group. RESULTS Cardiac output changed significantly when Paw was changed in the study group (P = 0.02), with the greatest change at the highest Paw at -11% (range: -19 to -9) compared with baseline. We found no significant changes over time in the control group. CONCLUSION This study shows that CO is affected by changes in mean airway pressure during HFOV in concordance with the known effects of mean airway pressure during conventional positive pressure ventilation. The mean changes are smaller than expected compared with earlier studies of conventional mechanical ventilation. Further studies are needed to better understand these relationships.
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Affiliation(s)
- N Gullberg
- Pediatric Anesthesia and Intensive Care, Astrid Lindgren Children's Hospital/Karolinska Hospital, S-171 76 Stockholm, Sweden.
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Bhatt-Mehta V, Donn SM. Gentamicin pharmacokinetics in term newborn infants receiving high-frequency oscillatory ventilation or conventional mechanical ventilation: a case-controlled study. J Perinatol 2003; 23:559-62. [PMID: 14566353 DOI: 10.1038/sj.jp.7210985] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE To compare the pharmacokinetics of gentamicin in infants receiving high-frequency oscillatory ventilation (HFOV) with infants receiving conventional mechanical ventilation. DESIGN A case-controlled study design was used to compare the pharmacokinetics of gentamicin in critically ill infants receiving HFOV and conventional mechanical ventilation. Medical records of all full-term newborn infants (> or =37 weeks gestational age) who received either high-frequency mechanical ventilation or conventional mechanical ventilation between 1991 and 2001 were reviewed and relevant patient demographics, renal function tests and gentamicin administration and plasma concentration data collected. Elimination rate constant, half-life, volume of distribution and clearance for both groups were calculated using standard kinetics equations. SETTING A tertiary care children's hospital. PATIENTS Newborn infants, > or =37 weeks gestational age, receiving gentamicin and high-frequency mechanical ventilation or conventional mechanical ventilation. MEASUREMENTS AND MAIN RESULTS In total, 18 patients were included in the conventional mechanical ventilation group and 15 in the HFOV group. The mean gentamicin dose for conventional mechanical ventilation and HFOV groups infants were 2.52+/-0.07 and 2.5+/-0.07 mg/kg/dose, respectively. Initial dosing interval was 12 hours in all of the conventional mechanical ventilation infants and 13 of the 15 HFOV infants. The dosing interval for the remaining two HFOV infants was 18 hours. No patient in either group demonstrated oliguria. Statistical analysis using the Student t-test for unequal variances yielded significant differences between the two groups with regard to elimination rate constant, half-life, volume of distribution and clearance, with a p value of <0.05 for all the observations. The mean of the highest P(aw) received by each patient in the HFOV group (19.2+/-4.05) was considerably higher than in the conventional mechanical ventilation group (13.4+2.23) (p>0.05). CONCLUSION Infants receiving HFOV had reduced gentamicin clearance. Full-term infants receiving HFOV should be initiated at gentamicin dosing intervals of 18 hours rather than the traditional 12 hours recommended for this age group.
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Affiliation(s)
- Varsha Bhatt-Mehta
- Department of Clinical Sciences, College of Pharmacy, University of Michigan, 200 E. Hospital Drive, Ann Arbor, MI 48109-0225, USA
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Osborn DA, Evans N. Randomized trial of high-frequency oscillatory ventilation versus conventional ventilation: effect on systemic blood flow in very preterm infants. J Pediatr 2003; 143:192-8. [PMID: 12970631 DOI: 10.1067/s0022-3476(03)00359-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE Low superior vena cava (SVC) flow is common in very preterm infants in the first day and strongly associated with periventricular hemorrhage and disability. We examined the effect of high-frequency oscillatory ventilation (HFOV) compared with conventional ventilation (CV) on SVC flow and right ventricular output. METHODS Forty-five infants <29 weeks were randomized before 1 hour of age to HFOV or CV. Echocardiography was performed on 43 infants at 3, 10, and 24 hours of age. Infants with low SVC flow (<50 mL/kg/min) or hypotension (mean blood pressure < or =20) were treated with volume and inotrope. RESULTS Infants allocated to HFOV (n=23) and to CV (n=20) were well matched. There was a nonsignificant trend toward more infants on HFOV having SVC flow <50 mL/kg/min (48% vs 20%) and receiving volume and inotropes (61% vs 40%). There were no significant differences in mean SVC flow or right ventricular output at 3, 10, or 24 hours. Infants on HFOV had a significantly higher calculated upper body vascular resistance at 10 hours and mean blood pressure at 24 hours. CONCLUSIONS There were no significant adverse effects of HFOV on systemic blood flow in very preterm infants during the first 24 hours of life.
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Affiliation(s)
- David A Osborn
- Royal Prince Alfred Hospital, Missenden Road, Camperdown, NSW 2050, Australia.
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Pellicer A, Gayá F, Madero R, Quero J, Cabañas F. Noninvasive continuous monitoring of the effects of head position on brain hemodynamics in ventilated infants. Pediatrics 2002; 109:434-40. [PMID: 11875138 DOI: 10.1542/peds.109.3.434] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
HYPOTHESIS Laying supine with the head in midline position improves cerebral venous return by preventing functional occlusion of the vessels of the neck. OBJECTIVES To assess changes in cerebral blood volume (DeltaCBV) and cerebral blood flow (CBF) with the position of the head in ventilated patients using a noninvasive method. The influence of the type of ventilation and birth weight was evaluated. METHODS Thirteen conventionally ventilated and 8 high-frequency oscillatory ventilated infants, with mean gestational ages and birth weights of 31 +/- 5 weeks (24--38) and 1575 +/- 803 g (560--3000), respectively, were studied 5.8 +/- 7.8 days (1--33) after birth. DeltaCBV (mL/100 g) and CBF (mL/100 g/min) were measured by near-infrared spectroscopy with the head in supine midline position (DeltaCBVs, CBFs) and rotated 90 to one side (DeltaCBVlat, CBFlat). Heart rate, peripheral saturation, transcutaneous PCO(2), and blood pressure were monitored continuously. Ventilatory settings remained constant throughout the study period. RESULTS Mean DeltaCBVs was lower than mean DeltaCBVlat, although no changes in blood pressure, transcutaneous PCO(2), oxygenation, or heart rate occurred. This change in DeltaCBV was not associated with the type of ventilation or birth weight, but the differences tended to be greater (dDeltaCBV = DeltaCBVlat-DeltaCBVs) in the smallest infants (<1200 g). In contrast, CBF did not vary. CONCLUSION The supine midline position of the head favors cerebral venous drainage and helps to prevent elevation of CBV. SPECULATION This finding may be important in the first days of life, particularly in tiny preterm infants recovering from lung disease with improving lung compliance, in which functional obstruction of cerebral venous drainage should be avoided.
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Affiliation(s)
- Adelina Pellicer
- Department of Neonatology, La Paz University Hospital, Madrid, Spain.
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Mehta S, Lapinsky SE, Hallett DC, Merker D, Groll RJ, Cooper AB, MacDonald RJ, Stewart TE. Prospective trial of high-frequency oscillation in adults with acute respiratory distress syndrome. Crit Care Med 2001; 29:1360-9. [PMID: 11445688 DOI: 10.1097/00003246-200107000-00011] [Citation(s) in RCA: 198] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To evaluate the safety and efficacy of high-frequency oscillatory ventilation (HFOV) in adult patients with the acute respiratory distress syndrome (ARDS) and oxygenation failure. DESIGN Prospective, clinical study. SETTING Intensive care and burn units of two university teaching hospitals. PATIENTS Twenty-four adults (10 females, 14 males, aged 48.5 +/- 15.2 yrs, Acute Physiology and Chronic Health Evaluation II score 21.5 +/- 6.9) with ARDS (lung injury score 3.4 +/- 0.6, Pao2/Fio2 98.8 +/- 39.0 mm Hg, and oxygenation index 32.5 +/- 19.6) who met one of the following criteria: Pao2 < or =65 mm Hg with Fio2 > or =0.6, or plateau pressure > or =35 cm H2O. INTERVENTIONS HFOV was initiated in patients with ARDS after varying periods of conventional ventilation (CV). Mean airway pressure (Paw) was initially set 5 cm H2O greater than Paw during CV, and was subsequently titrated to maintain oxygen saturation between 88% and 93% and Fio2 < or =0.60. MEASUREMENTS AND MAIN RESULTS Fio2, Paw, pressure amplitude of oscillation, frequency, blood pressure, heart rate, and arterial blood gases were monitored during the transition from CV to HFOV, and every 8 hrs thereafter for 72 hrs. In 16 patients who had pulmonary artery catheters in place, cardiac hemodynamics were recorded at the same time intervals. Throughout the HFOV trial, Paw was significantly higher than that applied during CV. Within 8 hrs of HFOV application, and for the duration of the trial, Fio2 and Paco2 were lower, and Pao2/Fio2 was higher than baseline values during CV. Significant changes in hemodynamic variables following HFOV initiation included an increase in pulmonary artery occlusion pressure (at 8 and 40 hrs) and central venous pressure (at 16 and 40 hrs), and a reduction in cardiac output throughout the course of the study. There were no significant changes in systemic or pulmonary pressure associated with initiation and maintenance of HFOV. Complications occurring during HFOV included pneumothorax in two patients and desiccation of secretions in one patient. Survival at 30 days was 33%, with survivors having been mechanically ventilated for fewer days before institution of HFOV compared with nonsurvivors (1.6 +/- 1.2 vs. 7.8 +/- 5.8 days; p =.001). CONCLUSIONS These findings suggest that HFOV has beneficial effects on oxygenation and ventilation, and may be a safe and effective rescue therapy for patients with severe oxygenation failure. In addition, early institution of HFOV may be advantageous.
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Affiliation(s)
- S Mehta
- Departments of Medicine and Anesthesia, Mount Sinai Hospital, Toronto, Ontario, Canada
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Moriette G, Paris-Llado J, Walti H, Escande B, Magny JF, Cambonie G, Thiriez G, Cantagrel S, Lacaze-Masmonteil T, Storme L, Blanc T, Liet JM, André C, Salanave B, Bréart G. Prospective randomized multicenter comparison of high-frequency oscillatory ventilation and conventional ventilation in preterm infants of less than 30 weeks with respiratory distress syndrome. Pediatrics 2001; 107:363-72. [PMID: 11158471 DOI: 10.1542/peds.107.2.363] [Citation(s) in RCA: 125] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Early use of high-frequency ventilation and exogenous surfactant is proposed as the optimal mode of ventilatory support in infants with respiratory distress syndrome. In very premature infants, we tested the hypothesis that high-frequency versus conventional ventilation could decrease exogenous surfactant requirements and improve pulmonary outcome, without altering the complication rate, including that of severe intraventricular hemorrhage. METHODS Preterm infants with a postmenstrual age of 24 to 29 weeks, presenting with respiratory distress syndrome were randomly assigned to high-frequency oscillatory ventilation (lung volume recruitment strategy) or conventional ventilation. RESULTS Two hundred seventy-three infants were enrolled. One hundred fifty-three had a postmenstrual age of 24 to 27 weeks, and 143 had a birth weight </=1000 g. One hundred thirty-four infants were randomized at 142 minutes of life (median) to receive conventional ventilation (mean postmenstrual age at birth: 27. 6 +/- 1.5 weeks; mean birth weight: 997 +/- 245 g); and 139 infants were randomized at 145 minutes of life to receive high-frequency ventilation (mean postmenstrual age at birth: 27.5 +/- 1.4 weeks; mean birth weight: 976 +/- 219 g). High-frequency ventilation, compared with conventional ventilation, was associated with a twofold reduction in the requirement for >/=2 instillations of exogenous surfactant (30% vs 62%; odds ratio:.27; 95% confidence interval:.16-.44) and no difference in pulmonary outcome. The incidence of severe intraventricular hemorrhage was 24% in the high-frequency group and 14% in the conventional ventilation group (adjusted odds ratio: 1.50; 95% confidence interval:.68-3.30). CONCLUSION Early use of high-frequency oscillatory ventilation in very premature infants decreases exogenous surfactant requirements, does not improve the pulmonary outcome, and may be associated with an increased incidence of severe intraventricular hemorrhage.
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Affiliation(s)
- G Moriette
- Department of Neonatology of University Hospitals, Paris, France.
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Bauer K, Buschkamp S, Marcinkowski M, Kössel H, Thome U, Versmold HT. Postnatal changes of extracellular volume, atrial natriuretic factor, and diuresis in a randomized controlled trial of high-frequency oscillatory ventilation versus intermittent positive-pressure ventilation in premature infants <30 weeks gestation. Crit Care Med 2000; 28:2064-8. [PMID: 10890665 DOI: 10.1097/00003246-200006000-00066] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES High-frequency oscillatory ventilation (HFOV) with a high lung volume strategy is an experimental mode of ventilating preterm infants aimed at achieving maximal alveolar recruitment Higher mean airway pressures are used during HFOV than during intermittent positive-pressure ventilation (IPPV), and the intrathoracic volume increase is relatively constant. Both factors increase the risk to depress organ blood flow and diuresis. Our objective was to test the hypothesis that high lung volume HFOV attenuates the postnatal reduction of extracellular volume in preterm infants by reducing plasma atrial natriuretic factor and diuresis. DESIGN Prospective, randomized, controlled clinical trial. SETTING University hospital, Level III neonatal intensive care unit. PATIENTS Premature infants <30 wks gestation requiring intubation for respiratory distress syndrome within the first 6 hrs of life; 15 infants (gestational age, 26 [24-29] wks, birth weight 814 [452-1340] g) were randomized to HFOV, 19 infants (gestational age 27 [24-39] wks, birth weight 930 [644-1490] g) to IPPV. INTERVENTIONS The randomized mode of ventilation was assigned within 1 hr after intubation. During HFOV mean airway pressure was increased as long as oxygenation improved and no lung overinflation was seen on chest radiograph. IPPV rates were > or =60/min. MEASUREMENTS AND MAIN RESULTS We measured extracellular volume (sucrose dilution) and atrial natriuretic factor on Day 1 and Day 3. Mean airway pressure, body weight, diuresis, and fluid intake were measured daily. During HFOV mean airway pressure was higher at 12 hrs (median 7 cm H2O vs. 4 cm H2O; p = .001) and 24 hrs (median 6 cm H2O vs. 3 cm H2O; p = .01). In both groups, extracellular volume decreased between Day 1 and Day 3 (HFOV from 428 +/- 126 mL to 344 +/- 145 mL [p = .003], IPPV from 466 +/- 108 mL to 414 +/- 124 mL [p = .01]) and diuresis increased (HFOV, from 2.5 +/- 1.7 to 4.6 +/- 0.9 mL/kg/hr [p = .001]; IPPV, from 2.8 +/- 1.6 to 4.2 +/- 1.0 mL/kg/hr [p = .01]). Plasma atrial natriuretic factor was not decreased in the HFOV group. CONCLUSIONS High lung volume HFOV as primary mode of ventilation in preterm infants <30 wks gestation did not result in unwanted fluid retention and a decrease in diuresis in the first days of life.
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Affiliation(s)
- K Bauer
- Department of Pediatrics, Universitätsklinikum Benjamin Franklin, Freie Universität Berlin, Germany
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Simma B, Fritz M, Fink C, Hammerer I. Conventional ventilation versus high-frequency oscillation: hemodynamic effects in newborn babies. Crit Care Med 2000; 28:227-31. [PMID: 10667528 DOI: 10.1097/00003246-200001000-00038] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE We conducted a prospective study to assess the hemodynamic effects of conventional mechanical ventilation (CMV) compared with high-frequency oscillation (HFO) in newborn babies with respiratory distress syndrome. METHODS A total of 18 consecutive term and preterm infants were examined by two-dimensional M-mode and pulsed Doppler echocardiography. RESULTS Five patients had to be excluded, three of them because of increasing cardiovascular support after initiation of HFO. The remaining 13 infants (seven males, six females) had a median gestational age of 33 wks (range, 25-40) and a birth weight of 2350 g (range, 790-3600). Patients entered the study at 21 hrs (range, 5-69) of life, receiving total maintenance fluid of 90 mL/kg/day (range, 60-120). Five babies (38%) needed continuous inotropic support. HFO was used as a rescue therapy in infants who failed with CMV. In all 13 patients, HFO significantly impaired cardiac performance compared with CMV by decreasing aortic velocity-time integral: median, 10.2 cm (range, 6.0-14.6) vs. 8.3 cm (range, 5.3-12.4; p<.002); stroke volume: median, 3.8 mL (range, 1.6-6.8) vs. 3.2 mL (range, 1.3-5.9; p<.002); and cardiac index: 281 mL/min/kg of body weight (range, 177-579) vs. 200 mL/min/kg of body weight (range, 156-591; p<.002). Fractional shortening was also significantly reduced: median, 0.31% (range, 0.24-0.44) vs. 0.29% (range, 0.20-0.34; p<.01), because of a significantly smaller left ventricular diastolic diameter during HFO: median, 1.4 cm (range, 1.0-1.9) vs. 1.4 cm (range, 0.9-1.8; p<.05), with a median difference of -0.07 cm (range, -0.4-0.2). HFO also causes a significant decrease in heart rate-corrected left ventricular ejection time: median, 0.25 sec (range, 0.23-0.28) vs. 0.23 sec (range, 0.21-0.26; p < .02) and heart rate-corrected velocity of circumferential fiber shortening (Vcfc): median, 1.3 circ/sec (range, 1.0-1.6) vs. 1.2 circ/sec (range, 0.9-1.4; p<.05). Left ventricular end-systolic wall stress (LVESWS; g/cm2) remained stable. The correlation between Vcfc and LVESWS did not show any significance (CMV, r2 = .2; HFO, r2 = .09). The regression line between Vcfc and LVESWS showed a higher y-intercept and steeper slope during CMV than during HFO. Heart rate, mean arterial pressure, and left ventricular systolic diameter remained unchanged. CONCLUSIONS In newborn babies, HFO significantly decreased left ventricular cardiac output caused by reduced left ventricular filling and HFO decreased contractility at higher mean airway pressures than with CMV.
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Affiliation(s)
- B Simma
- Intensive Care Unit, Children's Hospital, Innsbruck, Austria
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23
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Cools F, Offringa M. Meta-analysis of elective high frequency ventilation in preterm infants with respiratory distress syndrome. Arch Dis Child Fetal Neonatal Ed 1999; 80:F15-20. [PMID: 10325805 PMCID: PMC1720870 DOI: 10.1136/fn.80.1.f15] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AIM To summarise the evidence on the efficacy of elective high frequency ventilation compared with conventional ventilation in preterm infants with respiratory distress syndrome. METHODS A search from 1987 onwards was made on Embase, Medline, and the Cochrane Library. A questionnaire was also circulated during an international meeting on high frequency ventilation. To be included in the data synthesis, studies had to be randomised controlled trials comparing elective high frequency ventilation with conventional ventilation in preterm infants with respiratory failure due to respiratory distress syndrome; indices of mortality, chronic pulmonary morbidity, and other clinically relevant outcomes were compared. Studies were assessed for methodological validity according to explicit criteria. RESULTS Ten studies (a total number of 1345 preterm infants) were considered for data synthesis. No difference in mortality at 28 or 30 days, nor in oxygen dependency at 28 days was found between both types of ventilation. Reduced oxygen dependency at the postconceptional age of 36 weeks (RR 0.50, 95% CI 0.32-0.78) was found, but so was an increase in grades 3 and 4 intraventricular haemorrhage (IVH) (RR 1.31, 95% CI 1.04-1.66). Those studies using a high lung volume ventilatory strategy showed a significant decrease in oxygen dependency at the postconceptional age of 36 weeks (RR 0.44, 95% CI 0.27-0.73), but no increase in severe IVH (RR 0.78, 95% CI 0.45-1.37). CONCLUSIONS Although high frequency ventilation reduces chronic lung disease, it seems to increase the risk of severe IVH. These results are dominated by an early study where the absence of benefit on pulmonary outcomes, and the increase in adverse neurological events, could be related to the low volume ventilatory strategy used. Recent studies, using a high lung volume approach, show better pulmonary outcomes without any increase in intracranial morbidity. Still, uncertainty remains about long term pulmonary and neurodevelopmental outcome.
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MESH Headings
- Cerebral Hemorrhage/etiology
- High-Frequency Ventilation
- Humans
- Infant, Newborn
- Infant, Premature
- Infant, Premature, Diseases/etiology
- Leukomalacia, Periventricular/etiology
- Lung/physiopathology
- Lung Diseases, Obstructive/prevention & control
- Randomized Controlled Trials as Topic
- Respiration, Artificial
- Respiratory Distress Syndrome, Newborn/mortality
- Respiratory Distress Syndrome, Newborn/physiopathology
- Respiratory Distress Syndrome, Newborn/therapy
- Risk Factors
- Treatment Outcome
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Affiliation(s)
- F Cools
- Department of Neonatology, Emma Children's Hospital/Academic Medical Centre, Amsterdam, The Netherlands
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Bhuta T, Henderson-Smart DJ. Elective high-frequency oscillatory ventilation versus conventional ventilation in preterm infants with pulmonary dysfunction: systematic review and meta-analyses. Pediatrics 1997; 100:E6. [PMID: 9347000 DOI: 10.1542/peds.100.5.e6] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
OBJECTIVES To systematically review the evidence to determine whether the routine use of high-frequency oscillatory ventilation (HFOV) as compared with conventional ventilation (CV) is beneficial or harmful in preterm infants requiring mechanical ventilation for pulmonary failure principally due to respiratory distress syndrome. METHODS All randomized controlled trials of elective HFOV versus CV in preterm infants <36 weeks' gestation with respiratory failure mainly attributable to respiratory distress syndrome were identified from the literature through a search of MEDLINE, EMBASE, Oxford database of Perinatal trials, and previous reviews including cross-references and abstracts. Meta-analyses using event rate ratios (ERR), event rate difference, and if significant, number needed-to-treat were calculated (95% confidence limits were used for all analyses). Two prespecified subgroup analyses were performed. RESULTS Four published trials were included. Meta-analyses revealed the following ERR (95% confidence intervals) for HFOV versus CV: mortality at 28 to 30 days, 1.02 (0.76, 1.39); chronic lung disease (CLD) at 28 days, 0.86 (0.73, 1.01); mortality or CLD, 0.9 (0.80, 1. 01); air-leak syndromes, 1.13 (0.97, 1.33); mechanical ventilation at 28 days, 1.06 (0.84, 1.33); supplemental oxygen at discharge, 0. 59 (0.37, 0.92); intraventricular hemorrhage (IVH) all grades, 1.11 (0.95, 1.29); IVH (grades 3 or 4), 1.32 (1.01, 1.72); and periventricular leukomalacia, 1.39 (0.91, 2.13). In the subgroup of trials in which a high volume strategy (HVS) was used the ERR for CLD was 0.53 (0.36, 0.78); mortality or CLD, 0.56 (0.40, 0.77); supplemental oxygen at discharge, 0.57 (0.36, 0.92); IVH (all grades), 0.90 (0.61, 1.33); and IVH (grades 3 or 4), 0.84 (0.39, 1. 84). Results were similar to these for the trials using surfactant. One recent trial suggests that HFOV may reduce the cost of in-hospital care. CONCLUSIONS The overall meta-analysis is dominated by the HIFI study, which was criticized for its methodology and surfactant was not used. Subsequent studies, most of which used HVS and/or surfactant, have shown benefits in measures of CLD without an increase in rates of IVH. Caution is warranted in interpreting these results because: 1) the treatment is not blinded and this could affect some outcomes; 2) except for one small trial postneonatal survival, lung function, and neurodevelopment have not been reported from HVS trials; and 3) the benefits and disadvantages have not been reported in infants born at different gestational ages or different birth weights. Importantly, results from groups experienced in the use of HFOV may not be readily generalizable.
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Affiliation(s)
- T Bhuta
- NSW Center for Perinatal Health Services Research at the University of Sydney and Department of Neonatal Medicine, Royal Prince Alfred Hospital, Sydney, NSW, Australia
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