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Skinner S, Crossley K, Amberg B, Kashyap A, Hooper S, Deprest JA, Hodges R, DeKoninck P. The effects of partial amniotic carbon dioxide insufflation in an ovine model. Prenat Diagn 2018; 38:994-1003. [PMID: 30286262 DOI: 10.1002/pd.5368] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 09/27/2018] [Accepted: 09/27/2018] [Indexed: 12/26/2022]
Abstract
OBJECTIVE We aim to assess the effect of partial amniotic carbon dioxide insufflation (PACI) at increasing pressures on fetal acid-base, fetal-placental perfusion, and fetal membrane morphology in an ovine model. METHOD Pregnant ewes and fetuses were instrumented under isoflurane anesthesia at 105 days gestation (term 145 days) to monitor utero-placental blood flow, fetal and maternal blood pressure, heart rate, and blood gas status. One group (n = 6) was exposed to PACI (unheated dry CO2 ), involving 10 mm Hg stepwise increases in insufflation pressure (5 to 25 mm Hg), for 80 minutes followed by 20 minutes of desufflation. Un-insufflated controls (n = 5) were monitored for 100 minutes. At postmortem, fetal membranes were collected for histological analysis. RESULTS PACI at 25 mm Hg caused severe fetal hypercapnia (PaCO2 = 143 ± 5 vs 54 ± 5 mm Hg, P < 0.001), acidosis (pH = 6.85 ± 0.02 vs 7.25 ± 0.02, P < 0.001), hypoxia (SaO2 = 31 ± 4% vs 57 ± 4%, P = 0.01), and reduced uterine artery flow (50 ± 15 vs 196 ± 13 mL/min/kg, P = 0.005) compared with controls. These effects were greater at higher PACI pressures. PACI resulted in leukocyte infiltration in the amnion (1.77 × 10-5 ± 0.61 × 10-5 vs 0.38 × 10-5 ± 0.19 × 10-5 cells/μm2 , P = 0.04) and chorionic membranes (2.94 × 10-5 ± 0.67 × 10-5 vs 0.84 × 10-5 ± 0.42 × 10-5 cells/μm2 , P = 0.01). CONCLUSION Higher PACI pressures results in larger disturbances in fetal acid-base, uterine blood flow, and fetal membrane inflammation in sheep. Differences between human and sheep utero-placental structure should be considered.
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Affiliation(s)
- Sasha Skinner
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia.,The Department of Obstetrics and Gynaecology, Monash University, Clayton, Victoria, Australia.,Perinatal Services Monash Health, Monash Medical Centre, Clayton, Victoria, Australia
| | - Kelly Crossley
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia.,The Department of Obstetrics and Gynaecology, Monash University, Clayton, Victoria, Australia
| | - Ben Amberg
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia.,The Department of Obstetrics and Gynaecology, Monash University, Clayton, Victoria, Australia
| | - Aidan Kashyap
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia.,The Department of Obstetrics and Gynaecology, Monash University, Clayton, Victoria, Australia
| | - Stuart Hooper
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia.,The Department of Obstetrics and Gynaecology, Monash University, Clayton, Victoria, Australia
| | - Jan A Deprest
- Division of Woman and Child, Department of Obstetrics and Gynaecology, University Hospitals Leuven, Leuven, Belgium.,Department of Development and Regeneration, Cluster Women and Child, Faculty of Medicine, KU Leuven, Leuven, Belgium.,Institute of Women's Health, University College London, London, UK
| | - Ryan Hodges
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia.,The Department of Obstetrics and Gynaecology, Monash University, Clayton, Victoria, Australia.,Perinatal Services Monash Health, Monash Medical Centre, Clayton, Victoria, Australia
| | - Philip DeKoninck
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia.,The Department of Obstetrics and Gynaecology, Monash University, Clayton, Victoria, Australia.,Department of Obstetrics and Gynaecology, Erasmus MC, University Medical Center Rotterdam, The Netherlands
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Abstract
Therapeutic hypothermia is the only treatment currently recommended for moderate or severe encephalopathy of hypoxic‒ischaemic origin in term neonates. Though the effects of hypothermia on human physiology have been explored for many decades, much of the data comes from animal or adult studies; the latter originally after accidental hypothermia, followed by application of controlled hypothermia after cardiac arrest or trauma, or during cardiopulmonary bypass. Though this work is informative, the effects of hypothermia on neonatal physiology after perinatal asphyxia must be considered in the context of a prolonged hypoxic insult that has already induced a number of significant physiological sequelae. This article reviews the effects of therapeutic hypothermia on respiratory, cardiovascular, and metabolic parameters, including glycaemic control and feeding requirements. The potential pitfalls of blood‒gas analysis and overtreatment of physiological changes in cardiovascular parameters are also discussed. Finally, the effects of hypothermia on drug metabolism are covered, focusing on how the pharmacokinetics, pharmacodynamics, and dosing requirements of drugs frequently used in neonatal intensive care may change during therapeutic hypothermia.
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Abstract
Background Gum Arabic (GA), a nonabsorbable nutrient from the exudate of Acacia senegal, exerts a powerful immunomodulatory effect on dendritic cells, antigen-presenting cells involved in the initiation of both innate and adaptive immunity. On the other hand GA degradation delivers short chain fatty acids, which in turn have been shown to foster the expression of foetal haemoglobin in erythrocytes. Increased levels of erythrocyte foetal haemoglobin are known to impede the intraerythrocytic growth of Plasmodium and thus confer some protection against malaria. The present study tested whether gum arabic may influence the clinical course of malaria. Methods Human erythrocytes were in vitro infected with Plasmodium falciparum in the absence and presence of butyrate and mice were in vivo infected with Plasmodium berghei ANKA by injecting parasitized murine erythrocytes (1 × 106) intraperitoneally. Half of the mice received gum arabic (10% in drinking water starting 10 days before the day of infection). Results According to the in vitro experiments butyrate significantly blunted parasitaemia only at concentrations much higher (3 mM) than those encountered in vivo following GA ingestion (<1 μM). According to the in vivo experiments the administration of gum arabic slightly but significantly decreased the parasitaemia and significantly extended the life span of infected mice. Discussion GA moderately influences the parasitaemia and survival of Plasmodium-infected mice. The underlying mechanism remained, however, elusive. Conclusions Gum arabic favourably influences the course of murine malaria.
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