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Milej D, Rajaram A, Suwalski M, Morrison LB, Shoemaker LN, St. Lawrence K. Assessing the relationship between the cerebral metabolic rate of oxygen and the oxidation state of cytochrome-c-oxidase. NEUROPHOTONICS 2022; 9:035001. [PMID: 35874144 PMCID: PMC9298853 DOI: 10.1117/1.nph.9.3.035001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 06/22/2022] [Indexed: 05/07/2023]
Abstract
Significance: Hyperspectral near-infrared spectroscopy (hsNIRS) combined with diffuse correlation spectroscopy (DCS) provides a noninvasive approach for monitoring cerebral blood flow (CBF), the cerebral metabolic rate of oxygen ( CMRO 2 ) and the oxidation state of cytochrome-c-oxidase (oxCCO). CMRO 2 is calculated by combining tissue oxygen saturation ( S t O 2 ) with CBF, whereas oxCCO can be measured directly by hsNIRS. Although both reflect oxygen metabolism, a direct comparison has yet to be studied. Aim: We aim to investigate the relationship between CMRO 2 and oxCCO during periods of restricted oxygen delivery and lower metabolic demand. Approach: A hybrid hsNIRS/DCS system was used to measure hemodynamic and metabolic responses in piglets exposed to cerebral ischemia and anesthetic-induced reductions in brain activity. Results: Although a linear relationship was observed between CMRO 2 and oxCCO during ischemia, both exhibited a nonlinear relationship with respect to CBF. In contrast, linear correlation was sufficient to characterize the relationships between CMRO 2 and CBF and between the two metabolic markers during reduced metabolic demand. Conclusions: The observed relationship between CMRO 2 and oxCCO during periods of restricted oxygen delivery and lower metabolic demand indicates that the two metabolic markers are strongly correlated.
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Affiliation(s)
- Daniel Milej
- Lawson Health Research Institute, Imaging Program, London, Ontario, Canada
- Western University, Department of Medical Biophysics, London, Ontario, Canada
- Address all correspondence to Daniel Milej,
| | - Ajay Rajaram
- Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts, United States
| | - Marianne Suwalski
- Lawson Health Research Institute, Imaging Program, London, Ontario, Canada
- Western University, Department of Medical Biophysics, London, Ontario, Canada
| | - Laura B. Morrison
- Lawson Health Research Institute, Imaging Program, London, Ontario, Canada
| | - Leena N. Shoemaker
- Lawson Health Research Institute, Imaging Program, London, Ontario, Canada
- Western University, Department of Medical Biophysics, London, Ontario, Canada
- Western University, Department of Kinesiology, London, Ontario, Canada
| | - Keith St. Lawrence
- Lawson Health Research Institute, Imaging Program, London, Ontario, Canada
- Western University, Department of Medical Biophysics, London, Ontario, Canada
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Kumar VHS, Gugino S, Nielsen L, Chandrasekharan P, Koenigsknecht C, Helman J, Lakshminrusimha S. Protection from systemic pyruvate at resuscitation in newborn lambs with asphyxial cardiac arrest. Physiol Rep 2020; 8:e14472. [PMID: 32596995 PMCID: PMC7322497 DOI: 10.14814/phy2.14472] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2020] [Revised: 05/04/2020] [Accepted: 05/10/2020] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Infants with hypoxic-ischemic injury often require cardiopulmonary resuscitation. Mitochondrial failure to generate adenosine triphosphate (ATP) during hypoxic-ischemic reperfusion injury contributes to cellular damage. Current postnatal strategies to improve outcome in hypoxic-ischemic injury need sophisticated equipment to perform servo-controlled cooling. Administration of intravenous pyruvate, an antioxidant with favorable effects on mitochondrial bioenergetics, is a simple intervention that can have a global impact. We hypothesize that the administration of pyruvate following the return of spontaneous circulation (ROSC) would improve cardiac function, systemic hemodynamics, and oxygen utilization in the brain in newborn lambs with cardiac arrest (CA). METHODS Term lambs were instrumented, delivered by C-section and asphyxia induced by umbilical cord occlusion along with clamping of the endotracheal tube until asystole; Lambs resuscitated following 5 min of CA; upon ROSC, lambs were randomized to receive pyruvate or saline infusion over 90 min and ventilated for 150 min postinfusion. Pulmonary and systemic hemodynamics and arterial gases monitored. We measured plasma pyruvate, tissue lactate, and ATP levels (heart and brain) in both groups. RESULTS Time to ROSC was not different between the two groups. Systolic and diastolic blood pressures, stroke volume, arterial oxygen content, and cerebral oxygen delivery were similar between the two groups. The cerebral metabolic rate of oxygen was higher following pyruvate infusion; higher oxygen consumption in the brain was associated with lower plasma levels but higher brain ATP levels compared to the saline group. CONCLUSIONS Pyruvate promotes energy generation accompanied by efficient oxygen utilization in the brain and may facilitate additional neuroprotection in the presence of hypoxic-ischemic injury.
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Affiliation(s)
| | - Sylvia Gugino
- Department of PediatricsUniversity at BuffaloBuffaloNYUSA
| | - Lori Nielsen
- Department of PediatricsUniversity at BuffaloBuffaloNYUSA
| | | | | | - Justin Helman
- Department of PediatricsUniversity at BuffaloBuffaloNYUSA
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Sakurai A, Ihara S, Tagami R, Yamaguchi J, Sugita A, Kuwana T, Sawada N, Hori S, Taniguch T, Kinoshita K. Parameters Influencing Brain Oxygen Measurement by Regional Oxygen Saturation in Postcardiac Arrest Patients with Targeted Temperature Management. Ther Hypothermia Temp Manag 2019; 10:71-75. [PMID: 31825272 PMCID: PMC7044773 DOI: 10.1089/ther.2019.0032] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
In several studies, regional cerebral oxygen saturation (rSO2) has been measured in patients with postcardiac arrest syndrome (PCAS) to analyze the brain's metabolic status. However, the significance of rSO2 in PCAS patients remains unclear. In the present study, we investigated the relationship between rSO2 and physiological parameters. Comatose survivors of out-of-hospital PCAS with targeted temperature management (TTM) at 34°C for 24 hours were included. All patients were monitored for their rSO2 and additional parameters (arterial oxygen saturation [SaO2], hemoglobin [Hb], mean arterial pressure [MAP], arterial carbon dioxide pressure [PaCO2], and body temperature]) measured at the start of monitoring and 24 and 48 hours after return of spontaneous circulation (ROSC). Patients were divided into favorable and unfavorable groups, and the correlation between rSO2 and these physiological parameters was evaluated by multiple regression analysis. Forty-nine patients were included in the study, with 15 in the favorable group and 34 in the unfavorable group. There was no significant difference in the rSO2 value between the two groups at any time point. The multiple regression analysis of the favorable group revealed a moderate correlation between rSO2 and SaO2, Hb, and PaCO2 only at 24 hours (coefficients: 0.482, 0.422, and 0.531, respectively), whereas that of the unfavorable group revealed moderate correlations between rSO2 and Hb values at all time points, PaCO2 at 24 hours and MAP at 24 and 48 hours. rSO2 was moderately correlated to MAP in unfavorable patients. To optimize brain oxygen metabolic balance for PCAS patients with TTM measuring rSO2, we suggest total evaluation of each parameters of SaO2, Hb, MAP, and PaCO2.
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Affiliation(s)
- Atsushi Sakurai
- Division of Emergency and Critical Care Medicine, Department of Acute Medicine, Nihon University School of Medicine, Tokyo, Japan
- Address correspondence to: Atsushi Sakurai, MD, PhD, Division of Emergency and Critical Care Medicine, Department of Acute Medicine, Nihon University School of Medicine, 30-1 Oyaguchikamimachi Itabashi-ku, Tokyo 173-8610, Japan
| | - Shingo Ihara
- Division of Emergency and Critical Care Medicine, Department of Acute Medicine, Nihon University School of Medicine, Tokyo, Japan
| | - Rumi Tagami
- Division of Emergency and Critical Care Medicine, Department of Acute Medicine, Nihon University School of Medicine, Tokyo, Japan
| | - Junko Yamaguchi
- Division of Emergency and Critical Care Medicine, Department of Acute Medicine, Nihon University School of Medicine, Tokyo, Japan
| | - Atsunori Sugita
- Division of Emergency and Critical Care Medicine, Department of Acute Medicine, Nihon University School of Medicine, Tokyo, Japan
| | - Tsukasa Kuwana
- Division of Emergency and Critical Care Medicine, Department of Acute Medicine, Nihon University School of Medicine, Tokyo, Japan
| | - Nami Sawada
- Division of Emergency and Critical Care Medicine, Department of Acute Medicine, Nihon University School of Medicine, Tokyo, Japan
| | - Satoshi Hori
- Division of Emergency and Critical Care Medicine, Department of Acute Medicine, Nihon University School of Medicine, Tokyo, Japan
| | - Tetsuya Taniguch
- Department of Mathematics, Nihon University School of Medicine, Tokyo, Japan
| | - Kosaku Kinoshita
- Division of Emergency and Critical Care Medicine, Department of Acute Medicine, Nihon University School of Medicine, Tokyo, Japan
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Bale G, Mitra S, de Roever I, Sokolska M, Price D, Bainbridge A, Gunny R, Uria-Avellanal C, Kendall GS, Meek J, Robertson NJ, Tachtsidis I. Oxygen dependency of mitochondrial metabolism indicates outcome of newborn brain injury. J Cereb Blood Flow Metab 2019; 39:2035-2047. [PMID: 29775114 PMCID: PMC6775592 DOI: 10.1177/0271678x18777928] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
There is a need for a method of real-time assessment of brain metabolism during neonatal hypoxic-ischaemic encephalopathy (HIE). We have used broadband near-infrared spectroscopy (NIRS) to monitor cerebral oxygenation and metabolic changes in 50 neonates with HIE undergoing therapeutic hypothermia treatment. In 24 neonates, 54 episodes of spontaneous decreases in peripheral oxygen saturation (desaturations) were recorded between 6 and 81 h after birth. We observed differences in the cerebral metabolic responses to these episodes that were related to the predicted outcome of the injury, as determined by subsequent magnetic resonance spectroscopy derived lactate/N-acetyl-aspartate. We demonstrated that a strong relationship between cerebral metabolism (broadband NIRS-measured cytochrome-c-oxidase (CCO)) and cerebral oxygenation was associated with unfavourable outcome; this is likely to be due to a lower cerebral metabolic rate and mitochondrial dysfunction in severe encephalopathy. Specifically, a decrease in the brain tissue oxidation state of CCO greater than 0.06 µM per 1 µM brain haemoglobin oxygenation drop was able to predict the outcome with 64% sensitivity and 79% specificity (receiver operating characteristic area under the curve = 0.73). With further work on the implementation of this methodology, broadband NIRS has the potential to provide an early, cotside, non-invasive, clinically relevant metabolic marker of perinatal hypoxic-ischaemic injury.
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Affiliation(s)
- Gemma Bale
- Department of Medical Physics and Biomedical Engineering, University College London, London, UK
| | - Subhabrata Mitra
- Institute of Women's Health, University College London, London, UK
| | - Isabel de Roever
- Department of Medical Physics and Biomedical Engineering, University College London, London, UK
| | - Magdalena Sokolska
- Department of Medical Physics and Biomedical Engineering, University College London Hospital, London, UK
| | - David Price
- Department of Medical Physics and Biomedical Engineering, University College London Hospital, London, UK
| | - Alan Bainbridge
- Department of Medical Physics and Biomedical Engineering, University College London Hospital, London, UK
| | - Roxana Gunny
- Paediatric Neuroradiology, Great Ormond Street Hospital for Children, London, UK
| | | | - Giles S Kendall
- Neonatal Unit, University College London Hospital, London, UK
| | - Judith Meek
- Institute of Women's Health, University College London, London, UK
| | | | - Ilias Tachtsidis
- Department of Medical Physics and Biomedical Engineering, University College London, London, UK
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Rajaram A, Bale G, Kewin M, Morrison LB, Tachtsidis I, St. Lawrence K, Diop M. Simultaneous monitoring of cerebral perfusion and cytochrome c oxidase by combining broadband near-infrared spectroscopy and diffuse correlation spectroscopy. BIOMEDICAL OPTICS EXPRESS 2018; 9:2588-2603. [PMID: 30258675 PMCID: PMC6154190 DOI: 10.1364/boe.9.002588] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 05/04/2018] [Accepted: 05/07/2018] [Indexed: 05/23/2023]
Abstract
Preterm infants born with very low birth weights are at a high risk of brain injury, in part because the premature brain is believed to be prone to periods of low cerebral blood flow (CBF). Tissue damage is likely to occur if reduction in CBF is sufficient to impair cerebral energy metabolism for extended periods. Therefore, a neuromonitoring method that can detect reductions in CBF, large enough to affect metabolism, could alert the neonatal intensive care team before injury occurs. In this report, we present the development of an optical system that combines diffuse correlation spectroscopy (DCS) for monitoring CBF and broadband near-infrared spectroscopy (B-NIRS) for monitoring the oxidation state of cytochrome c oxidase (oxCCO) - a key biomarker of oxidative metabolism. The hybrid instrument includes a multiplexing system to enable concomitant DCS and B-NIRS measurements while avoiding crosstalk between the two subsystems. The ability of the instrument to monitor dynamic changes in CBF and oxCCO was demonstrated in a piglet model of neonatal hypoxia-ischemia (HI). Experiments conducted in eight animals, including two controls, showed that oxCCO exhibited a delayed response to ischemia while CBF and tissue oxygenation (StO2) responses were instantaneous. These findings suggest that simultaneous neuromonitoring of perfusion and metabolism could provide critical information regarding clinically significant hemodynamic events prior to the onset of brain injury.
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Affiliation(s)
- Ajay Rajaram
- Imaging Program, Lawson Health Research Institute, 268 Grosvenor St., London, ON, N6A 4V2, Canada
- Department of Medical Biophysics, Western University, 1151 Richmond St., London, ON, N6A 3K7, Canada
| | - Gemma Bale
- Medical Physics & Biomedical Engineering, University College London, Gower St., Bloomsbury, London, WC1E 6BT, United Kingdom
| | - Matthew Kewin
- Imaging Program, Lawson Health Research Institute, 268 Grosvenor St., London, ON, N6A 4V2, Canada
- Department of Medical Biophysics, Western University, 1151 Richmond St., London, ON, N6A 3K7, Canada
| | - Laura B. Morrison
- Imaging Program, Lawson Health Research Institute, 268 Grosvenor St., London, ON, N6A 4V2, Canada
| | - Ilias Tachtsidis
- Medical Physics & Biomedical Engineering, University College London, Gower St., Bloomsbury, London, WC1E 6BT, United Kingdom
| | - Keith St. Lawrence
- Imaging Program, Lawson Health Research Institute, 268 Grosvenor St., London, ON, N6A 4V2, Canada
- Department of Medical Biophysics, Western University, 1151 Richmond St., London, ON, N6A 3K7, Canada
| | - Mamadou Diop
- Imaging Program, Lawson Health Research Institute, 268 Grosvenor St., London, ON, N6A 4V2, Canada
- Department of Medical Biophysics, Western University, 1151 Richmond St., London, ON, N6A 3K7, Canada
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Owji ZP, Gilbert G, Saint-Martin C, Wintermark P. Brain Temperature Is Increased During the First Days of Life in Asphyxiated Newborns: Developing Brain Injury Despite Hypothermia Treatment. AJNR Am J Neuroradiol 2017; 38:2180-2186. [PMID: 28860214 DOI: 10.3174/ajnr.a5350] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 06/12/2017] [Indexed: 01/30/2023]
Abstract
BACKGROUND AND PURPOSE Therapeutic hypothermia is the current treatment for neonates with hypoxic-ischemic encephalopathy. It is believed to work by decreasing the brain temperature and reducing the baseline metabolism and energy demand of the brain. This study aimed to noninvasively assess brain temperature during the first month of life in neonates with hypoxic-ischemic encephalopathy treated with hypothermia. MATERIALS AND METHODS Neonates with hypoxic-ischemic encephalopathy treated with hypothermia and healthy neonates were enrolled prospectively. MR imaging was used to identify the presence and extent of brain injury. MR imaging multivoxel spectroscopy was used to derive brain temperatures in the basal ganglia and white matter at different time points during the first month of life. Brain temperature measurements were compared between neonates with hypoxic-ischemic encephalopathy and healthy neonates. RESULTS Forty-three term neonates with hypoxic-ischemic encephalopathy treated with hypothermia had a total of 74 spectroscopy scans, and 3 healthy term neonates had a total of 9 spectroscopy scans during the first month of life. Brain temperatures were lower in neonates with hypoxic-ischemic encephalopathy during hypothermia, compared with the healthy neonates (respectively, on day 1 of life: basal ganglia, 38.81°C ± 2.08°C, and white matter, 39.11°C ± 1.99°C; and on days 2-3 of life: basal ganglia, 38.25°C ± 0.91°C, and white matter, 38.54°C ± 2.79°C). However, neonates with hypoxic-ischemic encephalopathy who developed brain injury had higher brain temperatures during hypothermia (respectively, on day 1 of life: basal ganglia, 35.55°C ± 1.31°C, and white matter, 37.35°C ± 2.55°C; and on days 2-3 of life: basal ganglia, 35.20°C ± 1.15°C, and white matter, 35.44°C ± 1.90°C) compared with neonates who did not develop brain injury (respectively, on day 1 of life: basal ganglia, 34.46°C ± 1.09°C, and white matter, 33.97°C ± 1.42°C; and on days 2-3 of life: basal ganglia, 33.90°C ± 1.34°C, and white matter, 33.07°C ± 1.71°C). Also, brain temperatures tended to remain slightly higher in the neonates who developed brain injury around day 10 of life and around 1 month of age. CONCLUSIONS Therapeutic hypothermia using current guidelines decreased the brain temperature of neonates with hypoxic-ischemic encephalopathy during the first days of life but did not prevent an early increase of brain temperature in neonates with hypoxic-ischemic encephalopathy who developed brain injury despite this treatment.
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Affiliation(s)
- Z P Owji
- From the Department of Pediatrics, Division of Newborn Medicine, Research Institute of the McGill University Health Centre (Z.P.O., P.W.)
| | - G Gilbert
- MR Clinical Science (G.G.), Philips Healthcare, Montreal, Quebec, Canada
| | - C Saint-Martin
- Department of Pediatric Radiology (C.S.-M.), Montreal Children's Hospital, McGill University, Montreal, Quebec, Canada
| | - P Wintermark
- From the Department of Pediatrics, Division of Newborn Medicine, Research Institute of the McGill University Health Centre (Z.P.O., P.W.)
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Qi B, Hu L, Zhu L, Shang L, Sheng L, Wang X, Liu N, Wen N, Yu X, Wang Q, Yang Y. Metformin Attenuates Cognitive Impairments in Hypoxia–Ischemia Neonatal Rats via Improving Remyelination. Cell Mol Neurobiol 2016; 37:1269-1278. [DOI: 10.1007/s10571-016-0459-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 12/22/2016] [Indexed: 02/06/2023]
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Stark MJ, Hodyl NA, Belegar V KK, Andersen CC. Intrauterine inflammation, cerebral oxygen consumption and susceptibility to early brain injury in very preterm newborns. Arch Dis Child Fetal Neonatal Ed 2016; 101:F137-42. [PMID: 26265677 DOI: 10.1136/archdischild-2014-306945] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 07/24/2015] [Indexed: 11/04/2022]
Abstract
BACKGROUND In utero exposure to inflammation results in elevated cerebral oxygen consumption. This increased metabolic demand may contribute to the association between chorioamnionitis and intraventricular haemorrhage (P/IVH). We hypothesised that intrauterine inflammation imposes an elevated cerebral metabolic load and increased fractional oxygen extraction (cFTOE) with cFTOE further increased in the presence of early P/IVH. METHODS Eighty-three infants ≤30 weeks gestation were recruited. Exposure to intrauterine inflammation was determined by placental histology. Total internal carotid blood flow (Doppler ultrasound) and near infrared spectroscopy were measured and cerebral oxygen delivery (mcerbDO2), consumption (mcerbVO2) and cFTOE were calculated on days 1 and 3 of life. Primary outcome was defined as death or P/IVH >grade II (cranial sonograph) by day 3. RESULTS Infants exposed to intrauterine inflammation had higher total internal carotid blood flow (92 vs 63 mL/kg/min) and mcerbDO2 (13.7 vs 10.1 mL/kg/min) than those not exposed to inflammation. Newborns with P/IVH had both higher oxygen consumption and extraction compared with those without sonographic injury regardless of exposure to intrauterine inflammation. Further, in preterms exposed to inflammation, those with P/IVH had higher consumption (6.1 vs 4.8 mL/kg/min) and extraction than those without injury. These differences were observed only on day 1 of life. CONCLUSIONS Although P/IVH is multifactorial in preterm newborns, it is likely that cerebral hypoxic-ischaemia plays a central pathophysiological role. These data provide a mechanistic insight into this process and suggests that the increased cerebral metabolic load imposed by the presence of inflammation results in a higher risk of critical hypoxic ischaemia in the preterm with increased susceptibility to significant P/IVH.
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Affiliation(s)
- Michael J Stark
- Department of Neonatal Medicine, Women's and Children's Hospital, Adelaide, South Australia, Australia Robinson Research Institute, University of Adelaide, Adelaide, South Australia, Australia
| | - Nicolette A Hodyl
- Robinson Research Institute, University of Adelaide, Adelaide, South Australia, Australia
| | - Kiran Kumar Belegar V
- Department of Neonatal Medicine, Women's and Children's Hospital, Adelaide, South Australia, Australia
| | - Chad C Andersen
- Department of Neonatal Medicine, Women's and Children's Hospital, Adelaide, South Australia, Australia Robinson Research Institute, University of Adelaide, Adelaide, South Australia, Australia
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Diop M, Kishimoto J, Toronov V, Lee DSC, St. Lawrence K. Development of a combined broadband near-infrared and diffusion correlation system for monitoring cerebral blood flow and oxidative metabolism in preterm infants. BIOMEDICAL OPTICS EXPRESS 2015; 6:3907-18. [PMID: 26504641 PMCID: PMC4605050 DOI: 10.1364/boe.6.003907] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Revised: 07/30/2015] [Accepted: 07/31/2015] [Indexed: 05/23/2023]
Abstract
Neonatal neuromonitoring is a major clinical focus of near-infrared spectroscopy (NIRS) and there is an increasing interest in measuring cerebral blood flow (CBF) and oxidative metabolism (CMRO2) in addition to the classic tissue oxygenation saturation (StO2). The purpose of this study was to assess the ability of broadband NIRS combined with diffusion correlation spectroscopy (DCS) to measured changes in StO2, CBF and CMRO2 in preterm infants undergoing pharmaceutical treatment of patent ductus arteriosus. CBF was measured by both DCS and contrast-enhanced NIRS for comparison. No significant difference in the treatment-induced CBF decrease was found between DCS (27.9 ± 2.2%) and NIRS (26.5 ± 4.3%). A reduction in StO2 (70.5 ± 2.4% to 63.7 ± 2.9%) was measured by broadband NIRS, reflecting the increase in oxygen extraction required to maintain CMRO2. This study demonstrates the applicability of broadband NIRS combined with DCS for neuromonitoring in this patient population.
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Affiliation(s)
- Mamadou Diop
- Department of Medical Biophysics, University of Western Ontario, London, ON, Canada
- Imaging Division, Lawson Health Research Institute, London, ON, Canada
| | - Jessica Kishimoto
- Department of Medical Biophysics, University of Western Ontario, London, ON, Canada
- Imaging Division, Lawson Health Research Institute, London, ON, Canada
| | | | - David S. C. Lee
- Department of Neonatology, London Health Sciences Centre, London, ON, Canada
| | - Keith St. Lawrence
- Department of Medical Biophysics, University of Western Ontario, London, ON, Canada
- Imaging Division, Lawson Health Research Institute, London, ON, Canada
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Buckley EM, Patel SD, Miller BF, Franceschini MA, Vannucci SJ. In vivo Monitoring of Cerebral Hemodynamics in the Immature Rat: Effects of Hypoxia-Ischemia and Hypothermia. Dev Neurosci 2015; 37:407-16. [PMID: 26021410 DOI: 10.1159/000381704] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Accepted: 03/16/2015] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Neonatal hypoxic-ischemic (HI) encephalopathy occurs in 1-4 per 1,000 live term births and can cause devastating neurodevelopmental disabilities. Currently, therapeutic hypothermia (TH) is the only treatment with proven efficacy. Since TH is associated with decreased cerebral metabolism and cerebral blood flow (CBF), it is important to assess CBF at the bedside. Diffuse correlation spectroscopy (DCS) has emerged as a promising optical modality to noninvasively assess an index of CBF (CBFi) in both humans and animals. In this initial descriptive study, we employ DCS to monitor the evolution of CBFi following HI with or without TH in immature rats. We investigate potential relationships between CBF and subsequent cerebral damage. METHODS HI was induced on postnatal day 10 or 11 rat pups by right common carotid artery ligation followed by 60-70 min hypoxia (8% oxygen). After HI, the pups recovered for 4 h under hypothermia (HI-TH group, n = 23) or normothermia (HI-N group, n = 23). Bilateral measurements of hemispheric CBFi were made with DCS in unanesthetized animals at baseline, before HI, and 0, 1, 2, 3, 4, 5, and 24 h after HI. The animals were sacrificed at either 1 or 4 weeks, and brain injury was scored on an ordinal scale of 0-5 (0 = no injury). RESULTS Carotid ligation caused moderate bilateral decreases in CBFi. Following HI, an initial hyperemia was observed that was more prominent in the contralateral hemisphere. After initiation of TH, CBFi dropped significantly below baseline levels and remained reduced for the duration of TH. In contrast, CBFi in the HI-N group was not significantly decreased from baseline levels. Reductions in CBFi after 4 h of TH were not associated with reduced damage at 1 or 4 weeks. However, elevated ipsilateral CBFi and ipsilateral-to-contralateral CBFi ratios at 24 h were associated with worse outcome at 1 week after HI. CONCLUSIONS Both HI and TH alter CBFi, with significant differences in CBFi between hypothermic and normothermic groups after HI. CBFi may be a useful biomarker of subsequent cerebral damage.
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Affiliation(s)
- Erin M Buckley
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Mass., USA
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Kyng KJ, Skajaa T, Kerrn-Jespersen S, Andreassen CS, Bennedsgaard K, Henriksen TB. A Piglet Model of Neonatal Hypoxic-Ischemic Encephalopathy. J Vis Exp 2015:e52454. [PMID: 26068784 DOI: 10.3791/52454] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Birth asphyxia, which causes hypoxic-ischemic encephalopathy (HIE), accounts for 0.66 million deaths worldwide each year, about a quarter of the world's 2.9 million neonatal deaths. Animal models of HIE have contributed to the understanding of the pathophysiology in HIE, and have highlighted the dynamic process that occur in brain injury due to perinatal asphyxia. Thus, animal studies have suggested a time-window for post-insult treatment strategies. Hypothermia has been tested as a treatment for HIE in pdiglet models and subsequently proven effective in clinical trials. Variations of the model have been applied in the study of adjunctive neuroprotective methods and piglet studies of xenon and melatonin have led to clinical phase I and II trials(1,2). The piglet HIE model is further used for neonatal resuscitation- and hemodynamic studies as well as in investigations of cerebral hypoxia on a cellular level. However, it is a technically challenging model and variations in the protocol may result in either too mild or too severe brain injury. In this article, we demonstrate the technical procedures necessary for establishing a stable piglet model of neonatal HIE. First, the newborn piglet (< 24 hr old, median weight 1500 g) is anesthetized, intubated, and monitored in a setup comparable to that found in a neonatal intensive care unit. Global hypoxia-ischemia is induced by lowering the inspiratory oxygen fraction to achieve global hypoxia, ischemia through hypotension and a flat trace amplitude integrated EEG (aEEG) indicative of cerebral hypoxia. Survival is promoted by adjusting oxygenation according to the aEEG response and blood pressure. Brain injury is quantified by histopathology and magnetic resonance imaging after 72 hr.
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Affiliation(s)
- Kasper J Kyng
- The Perinatal Research Unit, Department of Pediatrics, Institute of Clinical Medicine, Aarhus University Hospital;
| | - Torjus Skajaa
- The Perinatal Research Unit, Department of Pediatrics, Institute of Clinical Medicine, Aarhus University Hospital
| | - Sigrid Kerrn-Jespersen
- The Perinatal Research Unit, Department of Pediatrics, Institute of Clinical Medicine, Aarhus University Hospital
| | - Christer S Andreassen
- Department of Otorhinolaryngology and Head & Neck Surgery, Institute of Clinical Medicine, Aarhus University Hospital
| | - Kristine Bennedsgaard
- The Perinatal Research Unit, Department of Pediatrics, Institute of Clinical Medicine, Aarhus University Hospital
| | - Tine B Henriksen
- The Perinatal Research Unit, Department of Pediatrics, Institute of Clinical Medicine, Aarhus University Hospital
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Evaluation of cerebral circulation and oxygen metabolism in infants using near-infrared light. Brain Dev 2014; 36:277-83. [PMID: 23800410 DOI: 10.1016/j.braindev.2013.05.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Revised: 05/25/2013] [Accepted: 05/29/2013] [Indexed: 11/22/2022]
Abstract
Bedside monitoring of cerebral circulation or oxygen metabolism in infants to appropriately manage circulation and establish the oxygen dose, aiming at improving the neurological prognosis, is needed in general clinical practice. Near-infrared spectroscopy is used for measurements of neonatal cerebral Hb oxygen saturation, cerebral blood volume, cerebral blood flow and cerebral metabolic rate of oxygen. Near-infrared time-resolved spectroscopy is particularly useful for bedside evaluation of cerebral circulation and oxygen metabolism because of its simple measurement procedure. Combined evaluation of cerebral blood volume and cerebral Hb oxygen saturation is expected to contribute to treatment centering on the brain in neonatal medical care.
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Nakamura S, Kusaka T, Yasuda S, Ueno M, Miki T, Koyano K, Nakamura M, Okada H, Okazaki K, Isobe K, Itoh S. Cerebral blood volume combined with amplitude-integrated EEG can be a suitable guide to control hypoxic/ischemic insult in a piglet model. Brain Dev 2013. [PMID: 23199679 DOI: 10.1016/j.braindev.2012.10.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
INTRODUCTION The purposes of this study are to compare two hypoxic/ischemic (H/I) insults using amplitude-integrated EEG (aEEG), alone or combined with cerebral blood volume (CBV), as a guide to control hypoxia and to determine which protocol most effectively produces a consistent degree of survivable neuropathological damage in a newborn piglet model of perinatal asphyxia. METHODS Eighteen piglets were subjected to H/I insult of 20-min low aEEG (LAEEG). After the 20-min, the aEEG group was maintained with low mean arterial blood pressure for 10min. The procedure for the aEEG plus CBV group was stopped if CBV became the rated value after 20min of LAEEG. We measured changes in CBV using a near-infrared time-resolved spectroscopy (TRS) and cerebral electrocortical activity using aEEG until 6h post-insult. At 5days post insult, the piglets' brains were perfusion-fixed and stained with hematoxylin/eosin. Piglets were grouped as undamaged or damaged; piglets that did not survive to 5days were grouped separately as dead. RESULTS Among surviving piglets, CBV combined with aEEG resulted in significantly greater percentage of damaged piglets than aEEG alone. CONCLUSIONS We conclude that combining CBV with aEEG may be a more effective guide to control H/I insult in a newborn piglet model than aEEG alone.
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Affiliation(s)
- Shinji Nakamura
- Department of Pediatrics, Faculty of Medicine, Kagawa University, Kagawa, Japan
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Gucuyener K, Beken S, Ergenekon E, Soysal S, Hirfanoglu I, Turan O, Unal S, Altuntas N, Kazanci E, Kulali F, Koc E, Turkyilmaz C, Onal E, Atalay Y. Use of amplitude-integrated electroencephalography (aEEG) and near infrared spectroscopy findings in neonates with asphyxia during selective head cooling. Brain Dev 2012; 34:280-6. [PMID: 21741190 DOI: 10.1016/j.braindev.2011.06.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2011] [Revised: 05/23/2011] [Accepted: 06/14/2011] [Indexed: 11/18/2022]
Abstract
BACKGROUND Amplitude-integrated electroencephalogram (aEEG) at <6 h is the best single outcome predictor in term infants with perinatal asphyxia at normothermia. Hypothermia treatment has changed the cutoff values for outcome prediction by using time at onset of normal trace and SWC. Cerebral hemodynamics and oxygenation changes detected by near infrared spectroscopy (NIRS) during hypothermia treatment in aphyxiated neonates are not a well known issue. AIM The aim of this study was to investigate the correlations between brain monitoring (amplitude integrated EEG and NIRS) and outcome in asphyxiated full-term infants with moderate/severe hypoxic-ischemic encephalopathy before, during and after hypothermia treatment. METHOD Ten neonates were recruited for hypothermia treatment by using the cool cap entry criteria. aEEG and NIRS were applied in 10 and 8 patients, respectively with moderate and severe hypoxic-ischemic encephalopathy before, just after brain cooling and rewarming periods. Patterns and voltages of aEEG backgrounds sleep-wake cycles (SWC) and NIRS values (TOI% and FTOE) were recorded. During the follow up their outcomes were assessed by using the Bayley Scales of Infant Development II. CONCLUSION Hypothermia changes the predictive value of early aEEG. Normalization of a baby's aEEG and the appearance of SWCs while being cooled occurs later. In our study one patient had normal aEEG background pattern at 80 and imminent SWC at 90 h after birth and still had normal Bayley scores at 24 months. Time to normal aEEG and SWC appearance should be carefully evaluated during the cooling period. NIRS values were different due to the clinical presentations of the patients.
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Affiliation(s)
- Kıvılcım Gucuyener
- Department of Pediatric Neurology, Gazi University, Medical Faculty, Besevler, Ankara, Turkey.
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