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Nocentini G, MacLaren G, Bartlett R, De Luca D, Perdichizzi S, Stoppa F, Marano M, Cecchetti C, Biasucci DG, Polito A, AlGhobaishi A, Guner Y, Gowda SH, Hirschl RB, Di Nardo M. Perfluorocarbons in Research and Clinical Practice: A Narrative Review. ASAIO J 2023; 69:1039-1048. [PMID: 37549675 DOI: 10.1097/mat.0000000000002017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/09/2023] Open
Abstract
Perfluorocarbons (PFCs) are organic liquids derived from hydrocarbons in which some of the hydrogen atoms have been replaced by fluorine atoms. They are chemically and biologically inert substances with a good safety profile. They are stable at room temperature, easy to store, and immiscible in water. Perfluorocarbons have been studied in biomedical research since 1960 for their unique properties as oxygen carriers. In particular, PFCs have been used for liquid ventilation in unusual environments such as deep-sea diving and simulations of zero gravity, and more recently for drug delivery and diagnostic imaging. Additionally, when delivered as emulsions, PFCs have been used as red blood cell substitutes. This narrative review will discuss the multifaceted utilization of PFCs in therapeutics, diagnostics, and research. We will specifically emphasize the potential role of PFCs as red blood cell substitutes, as airway mechanotransducers during artificial placenta procedures, as a means to improve donor organ perfusion during the ex vivo assessment, and as an adjunct in cancer therapies because of their ability to reduce local tissue hypoxia.
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Affiliation(s)
- Giulia Nocentini
- From the Academic Department of Pediatrics (DPUO), Immune and Infectious Diseases Division, Research Unit of Primary Immunodeficiencies, IRCCS Bmbino Gesù Children's Hospital, Rome, Italy
| | - Graeme MacLaren
- Cardiothoracic Intensive Care Unit, National University Health System, Singapore
| | - Robert Bartlett
- Department of Surgery, University of Michigan, Ann Arbor, Michigan
| | - Daniele De Luca
- Division of Pediatrics and Neonatal Critical Care, "A. Béclère" Medical Centre, Paris Saclay University Hospitals, APHP, Paris, France
- Physiopathology and Therapeutic Innovation Unit-INSERM U999, Paris Saclay University, Paris, France
| | | | - Francesca Stoppa
- Pediatric Intensive Care Unit, Children's Hospital Bambino Gesù, IRCCS, Rome, Italy
| | - Marco Marano
- Pediatric Intensive Care Unit, Children's Hospital Bambino Gesù, IRCCS, Rome, Italy
| | - Corrado Cecchetti
- Pediatric Intensive Care Unit, Children's Hospital Bambino Gesù, IRCCS, Rome, Italy
| | - Daniele G Biasucci
- Department of Clinical Science and Translational Medicine, "Tor Vergata" University of Rome, Rome, Italy
| | - Angelo Polito
- Pediatric Intensive Care Unit, Department of Woman, Child, and Adolescent Medicine, Geneva University Hospital, Geneva, Switzerland
| | - Abdullah AlGhobaishi
- Pediatric Critical Care Unit, Department of Pediatrics, King Fahad Armed Forces Hospital, Jeddah, Saudi Arabia
| | - Yit Guner
- Department of Pediatric Surgery, Children's Hospital of Orange County and University of California Irvine, Orange, California
| | - Sharada H Gowda
- Departments of Surgery and Pediatrics, Baylor College of Medicine and Texas Children's Hospital, Houston, Texas
| | - Ronald B Hirschl
- Section of Pediatric Surgery, Department of Surgery, University of Michigan, Ann Arbor, Michigan
| | - Matteo Di Nardo
- Pediatric Intensive Care Unit, Children's Hospital Bambino Gesù, IRCCS, Rome, Italy
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Bulletti FM, Sciorio R, Palagiano A, Bulletti C. The artificial uterus: on the way to ectogenesis. ZYGOTE 2023; 31:457-467. [PMID: 37357356 DOI: 10.1017/s0967199423000175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/27/2023]
Abstract
The inability to support the growth and development of a mature fetus up to delivery results in significant human suffering. Current available solutions include adoption, surrogacy, and uterus transplantation. However, these options are subject to several ethical, religious, economic, social, and medical concerns. Ectogenesis is the process in which an embryo develops in an artificial uterus from implantation through to the delivery of a live infant. This current narrative review summarizes the state of recent research focused on human ectogenesis. First, a literature search was performed to identify published reports of previous experiments and devices used for embryo implantation in an extracorporeally perfused human uterus. Furthermore, studies fitting that aim were selected and critically evaluated. Results were synthesized, interpreted, and used to design a prospective strategy for future research. Therefore, this study suggests that full ectogenesis might be obtained using a computer-controlled system with extracorporeal blood perfusion provided by a digitally controlled heart-lung-kidney system. From a clinical perspective, patients who will derive significant benefits from this technology are mainly those women diagnosed with anatomical abnormalities of the uterus and those who have undergone previous hysterectomies, numerous abortions, and experienced premature birth. Ectogenesis is the complete development of an embryo in an artificial uterus. It represents the solutions for millions of women suffering from premature deliveries, and the inability to supply growth and development of embryos/fetuses in the womb. In the future, ectogenesis might replace uterine transplantation and surrogacy.
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Affiliation(s)
| | - Romualdo Sciorio
- Edinburgh Assisted Conception Programme, Royal Infirmary of Edinburgh, EdinburghEH16 4SA, UK
| | - Antonio Palagiano
- Reproductive Science Pioneer, Assisted Fertilization Center (CFA), Naples, Italy
| | - Carlo Bulletti
- Extra Omnes, Assisted Reproductive Technology (ART), Center in Cattolica, Italy, and Associate Adjunct Professor, Department of Obstetrics, Gynecology, and Reproductive Science, Yale University, New Haven, Connecticut, USA
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Bauer K, Janke T, Schwarze R. Oxygen transport during liquid ventilation: an in vitro study. Sci Rep 2022; 12:1244. [PMID: 35075158 PMCID: PMC8786849 DOI: 10.1038/s41598-022-05105-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 01/06/2022] [Indexed: 11/10/2022] Open
Abstract
An in vitro experiment on the dissolved oxygen transport during liquid ventilation by means of measuring global oxygen concentration fields is presented within this work. We consider the flow in an idealized four generation model of the human airways in a range of peak Reynolds numbers of \documentclass[12pt]{minimal}
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\begin{document}$$\alpha = 3$$\end{document}α=3–5. Fluorescence quenching measurements were employed in order to visualize and quantify the oxygen distribution with high temporal and spatial resolution during the breathing cycle. Measurements with varying tidal volumes and oscillating frequencies reveal short living times of characteristic concentration patterns for all parameter variations. Similarities to typical velocity patterns in similar lung models persist only in early phases during each cycle. Concentration gradients are quickly homogenized by secondary motions within the lung model. A strong dependency of peak oxygen concentration on tidal volume is observed with considerably higher relative concentrations for higher tidal volumes.
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Affiliation(s)
- Katrin Bauer
- Institute of Mechanics and Fluid Dynamics, TU Bergakademie Freiberg, Freiberg, Germany.
| | | | - Rüdiger Schwarze
- Institute of Mechanics and Fluid Dynamics, TU Bergakademie Freiberg, Freiberg, Germany
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Liquid Ventilation in the Management of Preterm Infants. CURRENT STEM CELL REPORTS 2021. [DOI: 10.1007/s40778-021-00192-8] [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]
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See W, Morin C, Sage M, Stowe S, Gohier C, Nault S, Micheau P, Adler A, Fortin-Pellerin É. Air distribution within the lungs after total liquid ventilation in a neonatal ovine model. Respir Physiol Neurobiol 2021; 290:103666. [PMID: 33798788 DOI: 10.1016/j.resp.2021.103666] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 03/24/2021] [Accepted: 03/25/2021] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To gain insight into the total and regional lung aeration dynamics at the transition from total liquid ventilation (TLV) to conventional mechanical ventilation (GV). METHODS Neonatal lambs received either TLV for 4 h followed by GV (n = 15) or GV only (n = 11, controls). Monitoring was performed in the prone position with both videofluoroscopy and electrical impedance tomography (EIT) for the first 10 min of the transition. RESULTS Total and regional end-expiratory lung volumes were stable throughout the transition (p < 0.05). The percentage of tidal volume, liquid and/or gaseous, distributed to the different regions was stable (p < 0.05). Radiopacity of the nondependent regions markedly decreased at end-expiration (p < 0.01), reflecting the progressive transition to a gaseous end-expiratory lung volume. CONCLUSION Weaning to GV did not increase total or regional lung volumes, suggesting that the risk of overdistention was not increased. Residual perfluorocarbon in the dependent lung regions might account for the high O2 needs we observed in the first minutes of GV after TLV.
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Affiliation(s)
- Wendy See
- Department of Pharmacology-Physiology, Université de Sherbrooke, 3001, 12(e)Avenue Nord, Sherbrooke, QC, J1H 5H3, Canada.
| | - Christophe Morin
- Department of Pharmacology-Physiology, Université de Sherbrooke, 3001, 12(e)Avenue Nord, Sherbrooke, QC, J1H 5H3, Canada.
| | - Michaël Sage
- Department of Pharmacology-Physiology, Université de Sherbrooke, 3001, 12(e)Avenue Nord, Sherbrooke, QC, J1H 5H3, Canada.
| | - Symon Stowe
- Department of Computer Engineering, Carleton University, 1125 Colonel By Dr, Ottawa, K1S 5B6, ON, Canada.
| | - Catherine Gohier
- Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke. 3001, 12(e)Avenue Nord, Sherbrooke, QC, J1H 5H3, Canada.
| | - Stéphanie Nault
- Department of Pharmacology-Physiology, Université de Sherbrooke, 3001, 12(e)Avenue Nord, Sherbrooke, QC, J1H 5H3, Canada.
| | - Philippe Micheau
- Department of Mechanical Engineering, Université de Sherbrooke. 2500 Boulevard de l'Université, Sherbrooke, QC, J1K 2R1, Canada.
| | - Andy Adler
- Department of Computer Engineering, Carleton University, 1125 Colonel By Dr, Ottawa, K1S 5B6, ON, Canada.
| | - Étienne Fortin-Pellerin
- Department of Pharmacology-Physiology, Université de Sherbrooke, 3001, 12(e)Avenue Nord, Sherbrooke, QC, J1H 5H3, Canada; Department of Pediatrics, Université de Sherbrooke. 3001, 12(e)Avenue Nord, Sherbrooke, QC, J1H 5H3, Canada.
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Hou S, Ding H, Lv Q, Yin X, Song J, Landén NX, Fan H. Therapeutic effect of intravenous infusion of perfluorocarbon emulsion on LPS-induced acute lung injury in rats. PLoS One 2014; 9:e87826. [PMID: 24489970 PMCID: PMC3905038 DOI: 10.1371/journal.pone.0087826] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2013] [Accepted: 12/31/2013] [Indexed: 11/21/2022] Open
Abstract
Acute lung injury (ALI) and its more severe form, acute respiratory distress syndrome (ARDS) are the leading causes of death in critical care. Despite extensive efforts in research and clinical medicine, mortality remains high in these diseases. Perfluorocarbon (PFC), a chemical compound known as liquid ventilation medium, is capable of dissolving large amounts of physiologically important gases (mainly oxygen and carbon dioxide). In this study we aimed to investigate the effect of intravenous infusion of PFC emulsion on lipopolysaccharide (LPS) induced ALI in rats and elucidate its mechanism of action. Forty two Wistar rats were randomly divided into three groups: 6 rats were treated with saline solution by intratracheal instillation (control group), 18 rats were treated with LPS by intratracheal instillation (LPS group) and the other 18 rats received PFC through femoral vein prior to LPS instillation (LPS+PFC group). The rats in the control group were sacrificed 6 hours later after saline instillation. At 2, 4 and 6 hours of exposure to LPS, 6 rats in the LPS group and 6 rats in LPS+PFC group were sacrificed at each time point. By analyzing pulmonary pathology, partial pressure of oxygen in the blood (PaO2) and lung wet-dry weight ratio (W/D) of each rat, we found that intravenous infusion of PFC significantly alleviated acute lung injury induced by LPS. Moreover, we showed that the expression of pulmonary myeloperoxidase (MPO), intercellular adhesion molecule-1 (ICAM-1) of endothelial cells and CD11b of polymorphonuclear neutrophils (PMN) induced by LPS were significantly decreased by PFC treatment in vivo. Our results indicate that intravenous infusion of PFC inhibits the infiltration of PMNs into lung tissue, which has been shown as the core pathogenesis of ALI/ARDS. Thus, our study provides a theoretical foundation for using intravenous infusion of PFC to prevent and treat ALI/ARDS in clinical practice.
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Affiliation(s)
- Shike Hou
- Rescue Medical Research Institute, Affiliated Hospital of Logistics University of Chinese People's Armed Police Forces, Tianjin, P.R. China
| | - Hui Ding
- Rescue Medical Research Institute, Affiliated Hospital of Logistics University of Chinese People's Armed Police Forces, Tianjin, P.R. China
| | - Qi Lv
- Rescue Medical Research Institute, Affiliated Hospital of Logistics University of Chinese People's Armed Police Forces, Tianjin, P.R. China
| | - Xiaofeng Yin
- Rescue Medical Research Institute, Affiliated Hospital of Logistics University of Chinese People's Armed Police Forces, Tianjin, P.R. China
| | - Jianqi Song
- Rescue Medical Research Institute, Affiliated Hospital of Logistics University of Chinese People's Armed Police Forces, Tianjin, P.R. China
| | - Ning Xu Landén
- Molecular Dermatology Research Group, Center for Molecular Medicine (CMM), Karolinska University Hospital, Stockholm, Sweden
| | - Haojun Fan
- Rescue Medical Research Institute, Affiliated Hospital of Logistics University of Chinese People's Armed Police Forces, Tianjin, P.R. China
- * E-mail:
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Bossé D, Beaulieu A, Avoine O, Micheau P, Praud JP, Walti H. Neonatal total liquid ventilation: is low-frequency forced oscillation technique suitable for respiratory mechanics assessment? J Appl Physiol (1985) 2010; 109:501-10. [PMID: 20538848 DOI: 10.1152/japplphysiol.01042.2009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This study aimed to implement low-frequency forced oscillation technique (LFFOT) in neonatal total liquid ventilation (TLV) and to provide the first insight into respiratory impedance under this new modality of ventilation. Thirteen newborn lambs, weighing 2.5 + or - 0.4 kg (mean + or - SD), were premedicated, intubated, anesthetized, and then placed under TLV using a specially design liquid ventilator and a perfluorocarbon. The respiratory mechanics measurements protocol was started immediately after TLV initiation. Three blocks of measurements were first performed: one during initial respiratory system adaptation to TLV, followed by two other series during steady-state conditions. Lambs were then divided into two groups before undergoing another three blocks of measurements: the first group received a 10-min intravenous infusion of salbutamol (1.5 microg x kg(-1) x min(-1)) after continuous infusion of methacholine (9 microg x kg(-1) x min(-1)), while the second group of lambs was chest strapped. Respiratory impedance was measured using serial single-frequency tests at frequencies ranging between 0.05 and 2 Hz and then fitted with a constant-phase model. Harmonic test signals of 0.2 Hz were also launched every 10 min throughout the measurement protocol. Airway resistance and inertance were starkly increased in TLV compared with gas ventilation, with a resonant frequency < or = 1.2 Hz. Resistance of 0.2 Hz and reactance were sensitive to bronchoconstriction and dilation, as well as during compliance reduction. We report successful implementation of LFFOT to neonatal TLV and present the first insight into respiratory impedance under this new modality of ventilation. We show that LFFOT is an effective tool to track respiratory mechanics under TLV.
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Affiliation(s)
- Dominick Bossé
- Faculté de Médecine et des Sciences de la Santé, Département de Pédiatrie, 3001, 12e Ave. Nord, Sherbrooke, Québec, Canada J1H 5N4
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Cote M, Rogueda PGA, Griffiths PC. Effect of molecular weight and end-group nature on the solubility of ethylene oxide oligomers in 2H, 3H-decafluoropentane and its fully fluorinated analogue, perfluoropentane. J Pharm Pharmacol 2010; 60:593-9. [DOI: 10.1211/jpp.60.5.0004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Abstract
Fluorinated liquids possess high chemical and physical stability, are tolerated by the human body and, therefore, show great promise in biomedical fields; however, they require extensive formulation. Phase diagrams are reported here for a series of ethylene oxide oligomeric additives in 2H,3H-perfluoropentane (HPFP), a non-chlorofluorocarbon fluorinated liquid regarded as a model propellant for pressurized metered-dose inhalers. Over a wide range of temperatures and concentrations, dihydroxyl end-capped poly(ethylene glycols) (PEGs) exhibited a lower critical solution temperature (LCST) that was strongly molecular weight dependent. In contrast, monomethyl (and thus monohydroxy) and dimethyl end-capped poly(ethylene oxides) were fully miscible with HPFP over the same temperature and concentration ranges, suggesting that the phase behaviour was dominated by end-group/solvent interactions. By systematically substituting HPFP for the fully fluorinated analogue perfluoropentane, the ability of these end-groups to interact with the solvent was perturbed and LCST-type behaviour was induced in the previously fully miscible monomethyl and dimethyl end-capped PEGs. Concomitantly, with increasing perfluoropentane content, the LCST of the dihydroxyl end-capped PEGs was driven to lower temperatures. Therefore, the phase behaviour of these systems may be controlled by ‘tuning’ the end-group structure of the ethylene oxide oligomers, and varying the hydrogen bonding capabilities of the fluorinated solvents.
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Affiliation(s)
- Marie Cote
- School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, UK
| | - Philippe G A Rogueda
- AstraZeneca Research and Development, Charnwood, Bakewell Road, Loughborough, LH11 5RH, UK
| | - Peter C Griffiths
- School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, UK
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Spiess BD. Perfluorocarbon emulsions as a promising technology: a review of tissue and vascular gas dynamics. J Appl Physiol (1985) 2009; 106:1444-52. [PMID: 19179651 DOI: 10.1152/japplphysiol.90995.2008] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Perfluorocarbon (PFC) emulsions are halogen-substituted carbon nonpolar oils with resultant enhanced dissolved respiratory gas (O(2), N(2), CO(2), nitric oxide) capabilities. In the first demonstration of enhanced O(2) solubility, inhaled PFC could sustain rat metabolism. Intravenous emulsions were then trialed as "blood substitutes." In the last 10 yr, biocomputational modeling has enhanced our mechanistic understanding of PFCs. Contemporary research is now taking advantage of these physiological discoveries and applying PFCs as "oxygen therapeutics," as well as ways to enhance other gas movements. One particularly promising area of research is the treatment of gas embolism (arterial and venous emboli/decompression sickness). An expansive understanding of PFC-enhanced diffusive gas movements through tissue and vasculature may have analogous applications for O(2) or other respiratory gases and should provide a revolution in medicine. This review will stress the fundamental knowledge we now have regarding how respiratory gas movements are changed when intravenous PFC is present.
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Affiliation(s)
- Bruce D Spiess
- Department of Anesthesiology and Emergency Medicine, Virginia Commonwealth University Reanimation Engineering Shock Center, Richmond, Virginia, USA.
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Davies M, Dunster K, Wilson K. Gas exchange during perfluorocarbon liquid immersion: Life-support for the ex utero fetus. Med Hypotheses 2008; 71:91-8. [DOI: 10.1016/j.mehy.2008.02.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2008] [Revised: 01/30/2008] [Accepted: 02/03/2008] [Indexed: 10/22/2022]
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Abstract
The mortality rate associated with congenital diaphragmatic hernia (CDH) varies widely between centers and remains relatively high despite widespread use of new therapeutic modalities. Many of these have been implemented without properly controlled studies. Over the past 10 to 15 years, only 9 randomized trials enrolling a total of approximately 250 infants with CDH have been published. The limited evidence available suggests that better outcomes are observed by delivering infants with CDH at experienced centers, by delaying surgical repair until hemodynamic and respiratory stability is achieved, and by the judicious utilization of nonaggressive mechanical ventilation and permissive hypercapnea. Other therapeutic modalities, such as high frequency oscillatory ventilation, inhaled nitric oxide, and ECMO, may provide additional advantages for selected infants. There is a dire need to establish networks of centers that manage enough infants with CDH, to conduct appropriately sized randomized trials that can answer some of the critical questions about the management and long-term outcome of these infants.
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Affiliation(s)
- Fernando R Moya
- Department of Pediatrics, Coastal Area Health Education Center, Wilmington, NC 28402-9025, USA.
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Schmalisch G, Proquitté H, Schmidt M, Rüdiger M, Wauer RR. Inertance measurements by jet pulses in ventilated small lungs after perfluorochemical liquid (PFC) applications. Physiol Meas 2005; 26:239-49. [PMID: 15798299 DOI: 10.1088/0967-3334/26/3/009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Perfluorochemical liquid (PFC) liquids or aerosols are used for assisted ventilation, drug delivery, lung cancer hyperthermia and pulmonary imaging. The aim of this study was to investigate the effect of PFC liquid on the inertance (I) of the respiratory system in newborn piglets using partial liquid ventilation (PLV) with different volumes of liquid. End-inspiratory (I(in)) and end-expiratory (I(ex)) inertance were measured in 15 ventilated newborn piglets (age < 12 h, mean weight 724 +/- 93 g) by brief flow pulses before and 80 min after PLV using a PFC volume (PF5080, 3 M) of 10 ml kg(-1) (N = 5) or 30 ml kg(-1) (N = 10). I was calculated from the imaginary part of the measured respiratory input impedance by regression analysis. Straight tubes with 2-4 mm inner diameter were used to validate the equipment in vitro by comparison with the analytically calculated values. In vitro measurements showed that the measuring error of I was <5% and that the reproducibility was better than 1.5%. The correlation coefficient of the regression model to determine I was >0.988 in all piglets. During gas ventilation, I(in) and I(ex) (mean +/- SD) were 31.7 +/- 0.8 Pa l(-1) s(2) and 33.3 +/- 2.1 Pa l(-1) s(2) in the 10 ml group and 32.4 +/- 0.8 Pa l(-1) s(2) and 34.0 +/- 2.5 Pa l(-1) s(2) in the 30 ml group. However, I of the 3 mm endotracheal tube (ETT) used was already 26.4 Pa l(-1) s(2) (about 80% of measured I). During PLV, there was a minimal increase of I(in) to 33.1 +/- 2.5 Pa l(-1) s(2) in the 10 ml group and to 34.5 +/- 2.7 Pa l(-1) s(2) in the 30 ml group. In contrast, the increase of I(ex) was dramatically larger (p < 0.001) to 67.7 +/- 13.3 Pa l(-1) s(2) and to 74.8 +/- 9.3 Pa l(-1) s(2) in the 10 ml and 30 ml groups, respectively. Measurements of I by jet pulses in intubated small animals are reproducible. PFC increases the respiratory inertance, but the magnitude depends considerably on its spatial distribution which changes during the breathing cycle. Large differences between I(in) and I(ex) are an indicator for liquid in airways or the ETT.
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Affiliation(s)
- Gerd Schmalisch
- Clinic of Neonatology (Charité), Humboldt-University of Berlin, Schumannstrasse 20/21, D-10098 Berlin, Germany.
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Hirayama Y, Hirasawa H, Oda S, Shiga H, Matsuda K, Ueno H, Nakamura M. Partial liquid ventilation with FC-77 suppresses the release of lipid mediators in rat acute lung injury model. Crit Care Med 2004; 32:2085-9. [PMID: 15483418 DOI: 10.1097/01.ccm.0000142576.59654.bc] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To investigate whether the release of lipid mediators is suppressed in rats with experimentally induced acute lung injury managed with partial liquid ventilation (PLV) using FC-77. DESIGN Prospective, randomized controlled study. SETTING Research laboratory in a university. SUBJECTS Male Sprague-Dawley rats. INTERVENTIONS After tracheostomy was performed under general anesthesia, lung injury was induced by intratracheal instillation of HCl. The PLV group was then subjected to conventional gas ventilation for 30 mins, followed by PLV using FC-77. The control group was subjected to conventional gas ventilation throughout the study period. MEASUREMENTS AND MAIN RESULTS In the PLV group the following results were obtained: a) impaired oxygenation was markedly improved; b) the increase in the serum levels of lipid mediators such as leukotriene B4, thromboxane A2, and 6-keto-prostaglandin F1alpha was suppressed; and c) the increase in the concentrations of leukotriene B4, thromboxane A2, and 6-keto-prostaglandin F1alpha in the total lung homogenate at 180 mins after lung injury was also suppressed. CONCLUSION This study indicates that PLV using FC-77 suppresses the release of lipid mediators in our rat model of acute lung injury. However, further investigation is needed to clarify the precise mechanism of this effect.
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Affiliation(s)
- Yoh Hirayama
- Department of Emergency and Critical Care Medicine, Graduate School of Medicine, Chiba University, Chiba, Japan
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Abstract
Chronic lung disease (CLD) or bronchopulmonary dysplasia is a recognized sequel of preterm birth. With improving survival of infants at lower gestational ages, the incidence is on the rise. Pathological features of CLD include alveolar maldevelopment, with or without areas of pulmonary fibrosis. Assisted ventilation, infection/inflammation, oxygen administration, and fluid overload are the major risk factors in the evolution of CLD.Interventions, including the treatment of maternal infection, administration of prenatal glucocorticoids, and postnatal surfactant replacement therapy, improve the survival of preterm infants; however, their effect on CLD is difficult to determine. Strategies that have been effective in reducing CLD are the administration of retinol (vitamin A), high frequency oscillatory ventilation, and administration of glucocorticoids. Previous concerns regarding neurological problems associated with high frequency ventilation have not been substantiated in recent studies. Current recommendations do not advise the routine use of glucocorticoids due to concerns regarding long-term neurodevelopment. Therapies that were found to be ineffective in reducing the incidence of CLD include prenatal thyrotropin, cromolyn sodium (sodium cromoglycate), alpha-1 antitrypsin, superoxide dismutase, tocopherol (vitamin E), ascorbic acid (vitamin C), allopurinol, ambroxol, inositol, inhaled bronchodilators, and fluid restriction. Strategies that may be effective in reducing lung injury and subsequent CLD include avoiding assisted ventilation, lung protective ventilatory maneuvers, permissive hypercapnia, prevention of infection, early aggressive nutrition, and the treatment of a patent ductus arteriosus. The use of inhaled glucocorticoids improves pulmonary dynamics but long-term effects are unknown. The management of infants with established CLD has not been studied adequately, and the role of various ventilatory strategies for infants with established CLD is not clear. Adequate oxygenation should be maintained to prevent hypoxic episodes. Diuretics are helpful during acute decompensation; however, their long-term impact has not been well studied. Provision of adequate nutrition, immunization (routine and against respiratory syncytial virus), follow-up, and monitoring are the key elements in the long-term management of infants with CLD. Future research priorities should be to identify strategies to prevent/treat inflammation and promote the healing processes in the injured lung. The long-term effects of lung-protective ventilation strategies need to be studied.
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Affiliation(s)
- Prakesh S Shah
- Department of Paediatrics, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada.
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Abstract
Concerns about blood safety and the logistical problems associated with conventional transfusion have fuelled the search for effective alternatives (so-called blood substitutes). Such materials include hemoglobin derivatives and those based on synthetic, highly fluorinated, inert organic compounds called perfluorochemicals (PFCs). PFCs dissolve large volumes of oxygen and other gases, are unreactive in the body, and are excreted primarily as a vapor by exhalation. Liquid PFCs are immiscible with blood and other body fluids, but can be injected safely into the bloodstream as submicron emulsions. Emulsified PFCs have been evaluated in clinical trials as temporary, intravascular tissue-oxygenating fluids. One such emulsion, a commercial perflubron-based, phospholipid-stabilized formulation, is in advanced clinical trials as an alternative to transfusing donated (allogeneic) blood during surgery. Basic and clinical studies have shown that this emulsion can adequately maintain tissue oxygenation during acute blood loss with no abnormal hemodynamic changes. The use of PFC emulsions as an efficacious, short-term transfusion alternative underpins the longer term objective of producing a totally synthetic, bioengineered blood substitute.
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Affiliation(s)
- Kenneth C Lowe
- Biotechnology Laboratory, School of Life and Environmental Sciences, University of Nottingham, University Park, Nottingham, UK.
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Schmalisch G, Schmidt M, Proquitté H, Foitzik B, Rüdiger M, Wauer RR. Measurement of changes in respiratory mechanics during partial liquid ventilation using jet pulses. Crit Care Med 2003; 31:1435-41. [PMID: 12771615 DOI: 10.1097/01.ccm.0000063041.94690.76] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To compare the changes in respiratory mechanics within the breathing cycle in healthy lungs between gas ventilation and partial liquid ventilation using a special forced-oscillation technique. DESIGN Prospective animal trial. SETTINGS Animal laboratory in a university setting. SUBJECTS A total of 12 newborn piglets (age, <12 hrs; mean weight, 725 g). INTERVENTIONS After intubation and instrumentation, lung mechanics of the anesthetized piglets were measured by forced-oscillation technique at the end of inspiration and the end of expiration. The measurements were performed during gas ventilation and 80 mins after instillation of 30 mL/kg perfluorocarbon PF 5080. MEASUREMENTS AND MAIN RESULTS Brief flow pulses (width, 10 msec; peak flow, 16 L/min) were generated by a jet generator to measure the end-inspiratory and the end-expiratory respiratory input impedance in the frequency range of 4-32 Hz. The mechanical variables resistance, inertance, and compliance were determined by model fitting, using the method of least squares. At least in the lower frequency range, respiratory mechanics could be described adequately by an RIC single-compartment model in all piglets. During gas ventilation, the respiratory variables resistance and inertance did not differ significantly between end-inspiratory and end-expiratory measurements (mean [sd]: 4.2 [0.7] vs. 4.1 [0.6] kPa x L(-1) x sec, 30.0 [3.2] vs. 30.7 [3.1] Pa x L(-1) x sec2, respectively), whereas compliance decreased during inspiration from 14.8 (2.0) to 10.2 (2.4) mL x kPa(-1) x kg(-1) due to a slight lung overdistension. During partial liquid ventilation, the end-inspiratory respiratory mechanics was not different from the end-inspiratory respiratory mechanics measured during gas ventilation. However, in contrast to gas ventilation during partial liquid ventilation, compliance rose from 8.2 (1.0) to 13.0 (3.0) mL x kPa(-1) x kg(-1) during inspiration. During expiration, when perfluorocarbon came into the upper airways, both resistance and inertance increased considerably (mean with 95% confidence interval) by 34.3% (23.1%-45.8%) and 104.1% (96.0%-112.1%), respectively. CONCLUSIONS The changes in the respiratory mechanics within the breathing cycle are considerably higher during partial liquid ventilation compared with gas ventilation. This dependence of lung mechanics from the pulmonary gas volume hampers the comparability of dynamic measurements during partial liquid ventilation, and the magnitude of these changes cannot be detected by conventional respiratory-mechanical analysis using time-averaged variables.
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Affiliation(s)
- Gerd Schmalisch
- Clinic of Neonatology (Charité), Humboldt-University Berlin, Germany
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18
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Mammel MC. "Designer" perfluorocarbons and the lung. Crit Care Med 2002; 30:2395. [PMID: 12394983 DOI: 10.1097/00003246-200210000-00043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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