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Ndode-Ekane XE, Ali I, Gomez CS, Andrade P, Immonen R, Casillas-Espinosa P, Paananen T, Manninen E, Puhakka N, Smith G, Brady RD, Silva J, Braine E, Hudson M, Yamakawa GR, Jones NC, Shultz SR, Harris N, Wright DK, Gröhn O, Staba R, O’Brien TJ, Pitkänen A. Epilepsy phenotype and its reproducibility after lateral fluid percussion-induced traumatic brain injury in rats: Multicenter EpiBioS4Rx study project 1. Epilepsia 2024; 65:511-526. [PMID: 38052475 PMCID: PMC10922674 DOI: 10.1111/epi.17838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 11/21/2023] [Accepted: 11/27/2023] [Indexed: 12/07/2023]
Abstract
OBJECTIVE This study was undertaken to assess reproducibility of the epilepsy outcome and phenotype in a lateral fluid percussion model of posttraumatic epilepsy (PTE) across three study sites. METHODS A total of 525 adult male Sprague Dawley rats were randomized to lateral fluid percussion-induced brain injury (FPI) or sham operation. Of these, 264 were assigned to magnetic resonance imaging (MRI cohort, 43 sham, 221 traumatic brain injury [TBI]) and 261 to electrophysiological follow-up (EEG cohort, 41 sham, 220 TBI). A major effort was made to harmonize the rats, materials, equipment, procedures, and monitoring systems. On the 7th post-TBI month, rats were video-EEG monitored for epilepsy diagnosis. RESULTS A total of 245 rats were video-EEG phenotyped for epilepsy on the 7th postinjury month (121 in MRI cohort, 124 in EEG cohort). In the whole cohort (n = 245), the prevalence of PTE in rats with TBI was 22%, being 27% in the MRI and 18% in the EEG cohort (p > .05). Prevalence of PTE did not differ between the three study sites (p > .05). The average seizure frequency was .317 ± .725 seizures/day at University of Eastern Finland (UEF; Finland), .085 ± .067 at Monash University (Monash; Australia), and .299 ± .266 at University of California, Los Angeles (UCLA; USA; p < .01 as compared to Monash). The average seizure duration did not differ between UEF (104 ± 48 s), Monash (90 ± 33 s), and UCLA (105 ± 473 s; p > .05). Of the 219 seizures, 53% occurred as part of a seizure cluster (≥3 seizures/24 h; p >.05 between the study sites). Of the 209 seizures, 56% occurred during lights-on period and 44% during lights-off period (p > .05 between the study sites). SIGNIFICANCE The PTE phenotype induced by lateral FPI is reproducible in a multicenter design. Our study supports the feasibility of performing preclinical multicenter trials in PTE to increase statistical power and experimental rigor to produce clinically translatable data to combat epileptogenesis after TBI.
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Affiliation(s)
- Xavier Ekolle Ndode-Ekane
- A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FI-70211 Kuopio, Finland
| | - Idrish Ali
- Department of Neurology, Alfred Health, Melbourne, Australia
- Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Parkville, Australia
| | - Cesar Santana Gomez
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, United States
| | - Pedro Andrade
- A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FI-70211 Kuopio, Finland
| | - Riikka Immonen
- A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FI-70211 Kuopio, Finland
| | - Pablo Casillas-Espinosa
- Department of Neurology, Alfred Health, Melbourne, Australia
- Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Parkville, Australia
| | - Tomi Paananen
- A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FI-70211 Kuopio, Finland
| | - Eppu Manninen
- A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FI-70211 Kuopio, Finland
| | - Noora Puhakka
- A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FI-70211 Kuopio, Finland
| | - Gregory Smith
- Department of Neurosurgery, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, United States
| | - Rhys D. Brady
- Department of Neurology, Alfred Health, Melbourne, Australia
- Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Parkville, Australia
| | - Juliana Silva
- Department of Neurology, Alfred Health, Melbourne, Australia
- Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Parkville, Australia
| | - Emma Braine
- Department of Neurology, Alfred Health, Melbourne, Australia
- Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Parkville, Australia
| | - Matt Hudson
- Department of Neurology, Alfred Health, Melbourne, Australia
- Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Parkville, Australia
| | - Glen R. Yamakawa
- Department of Neurology, Alfred Health, Melbourne, Australia
- Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Parkville, Australia
| | - Nigel C. Jones
- Department of Neurology, Alfred Health, Melbourne, Australia
- Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Parkville, Australia
| | - Sandy R. Shultz
- Department of Neurology, Alfred Health, Melbourne, Australia
- Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Parkville, Australia
| | - Neil Harris
- Department of Neurosurgery, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, United States
| | - David K. Wright
- Department of Neurology, Alfred Health, Melbourne, Australia
- Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Parkville, Australia
| | - Olli Gröhn
- A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FI-70211 Kuopio, Finland
| | - Richard Staba
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, United States
| | - Terence J. O’Brien
- Department of Neuroscience, Monash University, Melbourne, Australia
- Department of Neurology, Alfred Health, Melbourne, Australia
- Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Parkville, Australia
| | - Asla Pitkänen
- A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FI-70211 Kuopio, Finland
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Immonen R, Smith G, Brady RD, Wright D, Johnston L, Harris NG, Manninen E, Salo R, Branch C, Duncan D, Cabeen R, Ndode-Ekane XE, Gomez CS, Casillas-Espinosa PM, Ali I, Shultz SR, Andrade P, Puhakka N, Staba RJ, O'Brien TJ, Toga AW, Pitkänen A, Gröhn O. Harmonization of pipeline for preclinical multicenter MRI biomarker discovery in a rat model of post-traumatic epileptogenesis. Epilepsy Res 2019; 150:46-57. [PMID: 30641351 DOI: 10.1016/j.eplepsyres.2019.01.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 12/12/2018] [Accepted: 01/05/2019] [Indexed: 02/07/2023]
Abstract
Preclinical imaging studies of posttraumatic epileptogenesis (PTE) have largely been proof-of-concept studies with limited animal numbers, and thus lack the statistical power for biomarker discovery. Epilepsy Bioinformatics Study for Antiepileptogenic Therapy (EpiBioS4Rx) is a pioneering multicenter trial investigating preclinical imaging biomarkers of PTE. EpiBios4Rx faced the issue of harmonizing the magnetic resonance imaging (MRI) procedures and imaging data metrics prior to its execution. We present here the harmonization process between three preclinical MRI facilities at the University of Eastern Finland (UEF), the University of Melbourne (Melbourne), and the University of California, Los Angeles (UCLA), and evaluate the uniformity of the obtained MRI data. Adult, male rats underwent a lateral fluid percussion injury (FPI) and were followed by MRI 2 days, 9 days, 1 month, and 5 months post-injury. Ex vivo scans of fixed brains were conducted 7 months post-injury as an end point follow-up. Four MRI modalities were used: T2-weighted imaging, multi-gradient-echo imaging, diffusion-weighted imaging, and magnetization transfer imaging, and acquisition parameters for each modality were tailored to account for the different field strengths (4.7 T and 7 T) and different MR hardwares used at the three participating centers. Pilot data collection resulted in comparable image quality across sites. In interim analysis (of data obtained by April 30, 2018), the within-site variation of the quantified signal properties was low, while some differences between sites remained. In T2-weighted images the signal-to-noise ratios were high at each site, being 35 at UEF, 48 at Melbourne, and 32 at UCLA (p < 0.05). The contrast-to-noise ratios were similar between the sites (9, 10, and 8, respectively). Magnetization transfer ratio maps had identical white matter/ gray matter contrast between the sites, with white matter showing 15% higher MTR than gray matter despite different absolute MTR values (MTR both in white and gray matter was 3% lower in Melbourne than at UEF, p < 0.05). Diffusion-weighting yielded different degrees of signal attenuation across sites, being 83% at UEF, 76% in Melbourne, and 80% at UCLA (p < 0.05). Fractional anisotropy values differed as well, being 0.81 at UEF, 0.73 in Melbourne, and 0.84 at UCLA (p < 0.05). The obtained values in sham animals showed low variation within each site and no change over time, suggesting high repeatability of the measurements. Quality control scans with phantoms demonstrated stable hardware performance over time. Timing of post-TBI scans was designed to target specific phases of the dynamic pathology, and the execution at different centers was highly accurate. Besides a few outliers, the 2-day scans were done within an hour from the target time point. At day 9, most animals were scanned within an hour from the target time point, and all but 2 outliers within 24 h from the target. The 1-month post-TBI scans were done within 31 ± 3 days. MRI procedures and animal physiology during scans were similar between the sites. Taken together, the 10% inter-site difference in FA and 3% difference in MTR values should be included into analysis as a covariate or balanced out in post-processing in order to detect disease-related effects on brain structure at the same scale. However, for a MRI biomarker for post-traumatic epileptogenesis to have realistic chance of being successfully translated to validation in clinical trials, it would need to be a robust TBI-induced structural change which tolerates the inter-site methodological variability described here.
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Affiliation(s)
- Riikka Immonen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, FIN-70211 Kuopio, Finland.
| | - Gregory Smith
- Department of Neurology, David Geffen School of Medicine at University of California at Los Angeles, Los Angeles, CA 90095, USA
| | - Rhys D Brady
- Departments of Neuroscience and Neurology, Central Clinical School, Alfred Health, Monash University, Melbourne, Victoria, Australia; Departments of Medicine and Neurology, The Royal Melbourne Hospital, The University of Melbourne, Parkville, Victoria, Australia
| | - David Wright
- Departments of Neuroscience and Neurology, Central Clinical School, Alfred Health, Monash University, Melbourne, Victoria, Australia
| | - Leigh Johnston
- Florey Institute of Neuroscience and Mental Health, Parkville, VIC 3052, Australia
| | - Neil G Harris
- Department of Neurology, David Geffen School of Medicine at University of California at Los Angeles, Los Angeles, CA 90095, USA
| | - Eppu Manninen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, FIN-70211 Kuopio, Finland
| | - Raimo Salo
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, FIN-70211 Kuopio, Finland
| | - Craig Branch
- Albert Einstein College of Medicine, New York, NY 10461, USA
| | - Dominique Duncan
- USC Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA 90033, USA
| | - Ryan Cabeen
- USC Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA 90033, USA
| | - Xavier Ekolle Ndode-Ekane
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, FIN-70211 Kuopio, Finland
| | - Cesar Santana Gomez
- Department of Neurology, David Geffen School of Medicine at University of California at Los Angeles, Los Angeles, CA 90095, USA
| | - Pablo M Casillas-Espinosa
- Departments of Neuroscience and Neurology, Central Clinical School, Alfred Health, Monash University, Melbourne, Victoria, Australia; Departments of Medicine and Neurology, The Royal Melbourne Hospital, The University of Melbourne, Parkville, Victoria, Australia
| | - Idrish Ali
- Departments of Neuroscience and Neurology, Central Clinical School, Alfred Health, Monash University, Melbourne, Victoria, Australia; Departments of Medicine and Neurology, The Royal Melbourne Hospital, The University of Melbourne, Parkville, Victoria, Australia
| | - Sandy R Shultz
- Departments of Neuroscience and Neurology, Central Clinical School, Alfred Health, Monash University, Melbourne, Victoria, Australia; Departments of Medicine and Neurology, The Royal Melbourne Hospital, The University of Melbourne, Parkville, Victoria, Australia
| | - Pedro Andrade
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, FIN-70211 Kuopio, Finland
| | - Noora Puhakka
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, FIN-70211 Kuopio, Finland
| | - Richard J Staba
- Department of Neurology, David Geffen School of Medicine at University of California at Los Angeles, Los Angeles, CA 90095, USA
| | - Terence J O'Brien
- Departments of Neuroscience and Neurology, Central Clinical School, Alfred Health, Monash University, Melbourne, Victoria, Australia; Departments of Medicine and Neurology, The Royal Melbourne Hospital, The University of Melbourne, Parkville, Victoria, Australia
| | - Arthur W Toga
- USC Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA 90033, USA
| | - Asla Pitkänen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, FIN-70211 Kuopio, Finland
| | - Olli Gröhn
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, FIN-70211 Kuopio, Finland
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Ciszek R, Ndode-Ekane XE, Gomez CS, Casillas-Espinosa PM, Ali I, Smith G, Puhakka N, Lapinlampi N, Andrade P, Kamnaksh A, Immonen R, Paananen T, Hudson MR, Brady RD, Shultz SR, O'Brien TJ, Staba RJ, Tohka J, Pitkänen A. Informatics tools to assess the success of procedural harmonization in preclinical multicenter biomarker discovery study on post-traumatic epileptogenesis. Epilepsy Res 2018; 150:17-26. [PMID: 30605864 DOI: 10.1016/j.eplepsyres.2018.12.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 12/11/2018] [Accepted: 12/26/2018] [Indexed: 12/28/2022]
Abstract
The Epilepsy Bioinformatics Study for Antiepileptogenic Therapy (EpiBioS4Rx) is a National Institutes for Neurological Diseases and Stoke funded Centers-Without-Walls international multidisciplinary study aimed at preventing epileptogenesis. The preclinical biomarker discovery in EpiBios4Rx applies a multicenter study design to allow the number of animals that are required for adequate statistical power for the analysis to be studied in an efficient manner. Further, the use of multiple centers mimics the clinical trial situation, and therefore potentially the chance of successful clinical translation of the outcomes of the study. Its successful implementation requires harmonization of procedures and data analyses between the three contributing centers in Finland, Australia, and USA. The objective of the present analysis was to develop metrics for analysis of the success of harmonization of procedures to guide further data analyses and plan the future multicenter preclinical studies. The interim analysis of data is based on the analysis of data from 212 rats with lateral fluid-percussion injury or sham-operation included in the biomarker discovery by April 30, 2018. The details of protocols, including production of injury, post-injury follow-up, blood sampling, electroencephalogram recording, and magnetic resonance imaging have been presented in the accompanying manuscripts in this Supplement. Implementation of protocols in EpiBios4Rx project participant centers was visualized in 2D using t-distributed stochastic neighborhood embedding (t-SNE). The protocols applied to each rat were presented as feature vectors of procedure related variables (e.g., impact pressure, anesthesia time). The total number of protocol features linked to each rat was 112. The missing data was accounted in visualization by utilizing imputation and adding the number of missing values as a third dimension to 2D t-SNE plot, resulting in a 3D overview of protocol data. Intraclass correlation coefficient (ICC) using Euclidean distances and area under receiver operating characteristic curve (AUC) of k-nearest neighbor classifier (KNN) were utilized to quantify the degree of clustering by center. Both subsets of data with incomplete protocol vectors omitted and missing protocol data imputed were assessed. Our data show that a visible clustering by center was observed in all t-SNE plots, except for day 7 neuroscores. Both ICC and AUC indicated clustering by center in all protocol variable subsets, excluding unimputed day 7 neuroscores (ICC 0.04 and AUC 0.6). ICC for imputed set of all protocol related variables was 0.1 and KNN AUC 0.92. In conclusion, both ICC and AUC indicated differences in protocol between EpiBios4Rx participating centers, which needs to be taken into account in data analysis. Importantly, the majority of observed differences are recoverable as they relate to insufficient updates in record keeping. While AUC score of KNN is a more sensitive measure for protocol harmonization than ICC for data that displays complex splintered clustering, ICC and AUC provide complementary measures to assess the degree of procedural harmonization. This experience should be helpful for other groups planning such multicenter post-traumatic epileptogenesis studies in the future.
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Affiliation(s)
- Robert Ciszek
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland.
| | | | - Cesar Santana Gomez
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Pablo M Casillas-Espinosa
- The Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Australia; Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Victoria, 3052, Australia
| | - Idrish Ali
- The Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Australia; Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Victoria, 3052, Australia
| | - Gregory Smith
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Noora Puhakka
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Niina Lapinlampi
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Pedro Andrade
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Alaa Kamnaksh
- Department of Anatomy, Physiology and Genetics, Uniformed Services University, MD, USA
| | - Riikka Immonen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Tomi Paananen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Matthew R Hudson
- The Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Australia; Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Victoria, 3052, Australia
| | - Rhys D Brady
- The Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Australia; Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Victoria, 3052, Australia
| | - Sandy R Shultz
- The Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Australia
| | - Terence J O'Brien
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA; Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Victoria, 3052, Australia; Department of Neurology, The Alfred Hospital, Commercial Road, Melbourne, Victoria, 3004, Australia; Department of Neurology, The Royal Melbourne Hospital, Grattan Street, Parkville, Victoria, 3050, Australia
| | - Richard J Staba
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Jussi Tohka
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Asla Pitkänen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
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Abstract
Six cases of a distinctive but poorly recognized variant of lymphangiomatosis with predominant or exclusive involvement of the soft tissues of the limb/limb girdle are described. The six patients were male and presented with slowly progressive swelling of the involved limb. The age of onset was at birth (three cases), 3 months (one case), 11 years (one case) and 12 years (one case). Five patients had involvement of the lower extremity and one of the right upper extremity. Three patients had concomitant asymptomatic bone involvement either in the affected limb (two cases) or in distant bones (one case). Only one patient had visceral involvement that was limited to the ipsilateral thorax and was associated with chylothorax. Diagnosis was confirmed in all but one patient by lymphangiography. Treatment consisted principally of surgical reduction with significant clinical improvement. No patient later developed systemic involvement and the clinical course was benign. The bone lesions did not progress in any patient. Histologically, each case was characterised by interconnecting, dilated lymphatic spaces, lined by a single, attenuated layer of endothelial cells, involving the dermis, subcutis, and occasionally, underlying fascia and skeletal muscle with characteristic and extensive "dissection" of collagen and surrounding normal adnexal structures. Despite the absence of red blood cells in the vascular spaces, interstitial hemosiderin deposition was prominent in four cases. As opposed to most cases of lymphangiomatosis, which usually have extensive visceral involvement associated with a very poor prognosis, involvement in this variant is limited almost exclusively to soft tissues of the limb and bone and is associated with good prognosis.
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Affiliation(s)
- C S Gomez
- Department of Histopathology, St. Thomas's Hospital, London, England
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Hess JR, Macdonald VW, Gomez CS, Coppes V. Increased vascular resistance with hemoglobin-based oxygen carriers. Artif Cells Blood Substit Immobil Biotechnol 1994; 22:361-72. [PMID: 7994360 DOI: 10.3109/10731199409117867] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
PURPOSE To compare the effects of resuscitation with hemoglobin-based oxygen-carriers and conventional resuscitation fluids on hemodynamics, oxygen transport, and oxygen consumption in an animal model of the use of these fluids in the treatment of hemorrhagic shock. PROTOCOL Twenty-eight immature swine were surgically prepared, allowed to recover five days, water deprived for 48 hours, hemorrhaged of 25 ml/kg over one hour, resuscitated promptly with 1) Ringer's lactate, 75 ml/kg, 2) 7% albumin in Ringer's acetate, 25 ml/kg, 3) 9% unmodified hemoglobin in Ringer's acetate, 25 ml/kg, or 4) 9% alpha alpha-crosslinked hemoglobin in Ringer's acetate, 25 ml/kg, and observed with three hours of hemodynamic and oxygen transport measurements. RESULTS Systemic and pulmonary vascular resistance were increased in hemoglobin-treated animals to more than twice the levels seen in crystalloid- or colloid-treated controls. Oxygen consumption and the rate of correction of lactic acidosis were not increased in hemoglobin-treated animals. CONCLUSIONS Increased vascular resistance limits the oxygen transport benefit of cell-free-hemoglobin-based oxygen carriers. Cell-free-hemoglobin-induced increases in vascular resistance may place animals' hearts on an unfavorable portion of the Frank-Starling curve as well as complicate further medical treatment by reducing the animals' tolerance to increases in blood viscosity.
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Affiliation(s)
- J R Hess
- Division of Blood Research, Letterman Army Institute of Research, Presidio of San Francisco, CA 94129-6800
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