1
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Chin K, Jiang H, Steinberg BE, Goldenberg NM, Desjardins JF, Kabir G, Liu E, Vanama R, Baker AJ, Deschamps A, Simpson JA, Maynes JT, Vinogradov SA, Connelly KA, Mazer CD, Hare GMT. Bilateral nephrectomy impairs cardiovascular function and cerebral perfusion in a rat model of acute hemodilutional anemia. J Appl Physiol (1985) 2024; 136:1245-1259. [PMID: 38385183 DOI: 10.1152/japplphysiol.00858.2023] [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] [Received: 11/28/2023] [Revised: 01/30/2024] [Accepted: 02/15/2024] [Indexed: 02/23/2024] Open
Abstract
Anemia and renal failure are independent risk factors for perioperative stroke, prompting us to assess the combined impact of acute hemodilutional anemia and bilateral nephrectomy (2Nx) on microvascular brain Po2 (PBro2) in a rat model. Changes in PBro2 (phosphorescence quenching) and cardiac output (CO, echocardiography) were measured in different groups of anesthetized Sprague-Dawley rats (1.5% isoflurane, n = 5-8/group) randomized to Sham 2Nx or 2Nx and subsequently exposed to acute hemodilutional anemia (50% estimated blood volume exchange with 6% hydroxyethyl starch) or time-based controls (no hemodilution). Outcomes were assessed by ANOVA with significance assigned at P < 0.05. At baseline, 2Nx rats demonstrated reduced CO (49.9 ± 9.4 vs. 66.3 ± 19.3 mL/min; P = 0.014) and PBro2 (21.1 ± 2.9 vs. 32.4 ± 3.1 mmHg; P < 0.001) relative to Sham 2Nx rats. Following hemodilution, 2Nx rats demonstrated a further decrease in PBro2 (15.0 ± 6.3 mmHg, P = 0.022). Hemodiluted 2Nx rats did not demonstrate a comparable increase in CO after hemodilution compared with Sham 2Nx (74.8 ± 22.4 vs. 108.9 ± 18.8 mL/min, P = 0.003) that likely contributed to the observed reduction in PBro2. This impaired CO response was associated with reduced fractional shortening (33 ± 9 vs. 51 ± 5%) and increased left ventricular end-systolic volume (156 ± 51 vs. 72 ± 15 µL, P < 0.001) suggestive of systolic dysfunction. By contrast, hemodiluted Sham 2Nx animals demonstrated a robust increase in CO and preserved PBro2. These data support the hypothesis that the kidney plays a central role in maintaining cerebral perfusion and initiating the adaptive increase in CO required to optimize PBro2 during acute anemia.NEW & NOTEWORTHY This study has demonstrated that bilateral nephrectomy acutely impaired cardiac output (CO) and microvascular brain Po2 (PBro2), at baseline. Following acute hemodilution, nephrectomy prevented the adaptive increase in CO associated with acute hemodilution leading to a further reduction in PBro2, accentuating the degree of cerebral tissue hypoxia. These data support a role for the kidney in maintaining PBro2 and initiating the increase in CO that optimized brain perfusion during acute anemia.
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Affiliation(s)
- Kyle Chin
- Department of Anesthesiology and Pain Medicine, St Michael's Hospital, University of Toronto, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Helen Jiang
- Department of Anesthesiology and Pain Medicine, St Michael's Hospital, University of Toronto, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Benjamin E Steinberg
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- Department of Anesthesia and Pain Medicine, The Hospital for Sick Children, The University of Toronto, Toronto, Ontario, Canada
- Department of Anesthesiology and Pain Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Neil M Goldenberg
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- Department of Anesthesia and Pain Medicine, The Hospital for Sick Children, The University of Toronto, Toronto, Ontario, Canada
- Department of Anesthesiology and Pain Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Jean-Francois Desjardins
- Keenan Research Centre for Biomedical Science in the Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada
- Division of Cardiology, Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Golam Kabir
- Keenan Research Centre for Biomedical Science in the Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada
- Division of Cardiology, Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Elaine Liu
- Department of Anesthesiology and Pain Medicine, St Michael's Hospital, University of Toronto, Toronto, Ontario, Canada
- Keenan Research Centre for Biomedical Science in the Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada
| | - Ramesh Vanama
- Department of Anesthesia and Pain Medicine, The Hospital for Sick Children, The University of Toronto, Toronto, Ontario, Canada
| | - Andrew J Baker
- Department of Anesthesiology and Pain Medicine, St Michael's Hospital, University of Toronto, Toronto, Ontario, Canada
- Keenan Research Centre for Biomedical Science in the Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Alain Deschamps
- Institut de Cardiologie de Montréal, Université de Montréal, Montreal Quebec, Canada
| | - Jeremy A Simpson
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
- IMPART investigator team Canada (https://impart.team/), Saint John, New Brunswick, Canada
| | - Jason T Maynes
- Department of Anesthesia and Pain Medicine, The Hospital for Sick Children, The University of Toronto, Toronto, Ontario, Canada
- Department of Anesthesiology and Pain Medicine, University of Toronto, Toronto, Ontario, Canada
- Program in Molecular Medicine, Hospital for Sick Children's Research Institute, Toronto, Ontario, Canada
| | - Sergei A Vinogradov
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Kim A Connelly
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- Division of Cardiology, Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - C David Mazer
- Department of Anesthesiology and Pain Medicine, St Michael's Hospital, University of Toronto, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- Department of Anesthesiology and Pain Medicine, University of Toronto, Toronto, Ontario, Canada
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada
| | - Gregory M T Hare
- Department of Anesthesiology and Pain Medicine, St Michael's Hospital, University of Toronto, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- Department of Anesthesiology and Pain Medicine, University of Toronto, Toronto, Ontario, Canada
- Keenan Research Centre for Biomedical Science in the Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada
- IMPART investigator team Canada (https://impart.team/), Saint John, New Brunswick, Canada
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2
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Wang JY, Song QL, Wang YL, Jiang ZM. Urinary oxygen tension and its role in predicting acute kidney injury: A narrative review. J Clin Anesth 2024; 93:111359. [PMID: 38061226 DOI: 10.1016/j.jclinane.2023.111359] [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] [Received: 04/22/2023] [Revised: 11/12/2023] [Accepted: 12/01/2023] [Indexed: 01/14/2024]
Abstract
Acute kidney injury occurs frequently in the perioperative setting. The renal medulla often endures hypoxia or hypoperfusion and is susceptible to the imbalance between oxygen supply and demand due to the nature of renal blood flow distribution and metabolic rate in the kidney. The current available evidence demonstrated that the urine oxygen pressure is proportional to the variations of renal medullary tissue oxygen pressure. Thus, urine oxygenation can be a candidate for reflecting the change of oxygen in the renal medulla. In this review, we discuss the basic physiology of acute kidney injury, as well as techniques for monitoring urine oxygen tension, confounding factors affecting the reliable measurement of urine oxygen tension, and its clinical use, highlighting its potential role in early detection and prevention of acute kidney injury.
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Affiliation(s)
- Jing-Yan Wang
- Department of Anesthesia, Shaoxing People's Hospital, Shaoxing 312000, Zhejiang Province, China
| | - Qi-Liang Song
- Department of Anesthesia, Shaoxing People's Hospital, Shaoxing 312000, Zhejiang Province, China
| | - Yu-Long Wang
- Department of Anesthesia, Shaoxing People's Hospital, Shaoxing 312000, Zhejiang Province, China
| | - Zong-Ming Jiang
- Department of Anesthesia, Shaoxing People's Hospital, Shaoxing 312000, Zhejiang Province, China.
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3
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Rocos B, Wong IH, Jentzsch T, Strantzas S, Lewis SJ. The Effect of Anaemia on Intra-operative Neuromonitoring Following Correction of Large Scoliosis Curves: Two Case Reports. Cureus 2024; 16:e59353. [PMID: 38817484 PMCID: PMC11138233 DOI: 10.7759/cureus.59353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/25/2024] [Indexed: 06/01/2024] Open
Abstract
The correction of anemia is important in reversing significant intraoperative bilateral motor-evoked potential (MEP) loss following rod placement for correction of large scoliosis curves. This article presents a retrospective review of intraoperative neuromonitoring (IONM) data, anesthesia records, and medical charts of two patients with significant bilateral MEP changes associated with posterior spinal surgery for deformity correction. A 70 kg 12-year-old and a 44 kg 16-year-old female with main thoracic curves underwent a posterior scoliosis correction with multilevel posterior column osteotomies. Following rod insertion, significant reduction in the bilateral lower extremity MEP occurred in both cases despite mean arterial pressure exceeding 70 mmHg, which was presumed to be due to the scale of the correction attempted in the setting of haemorrhage which rendered the patient acutely anaemic, thus compromising cord vasculature and oxygen delivery. The rods were removed and packed red blood cell transfusions were administered in response to acute anaemia as a result of haemorrhage in both cases. Neither was noted to be anaemic preoperatively. Once the MEP signals improved, the rods were reinserted and correction was attempted, limited by neuromonitoring signals and resistance of the bony anchors to pullout. At closure, the MEPs were near baseline in the first case and >50% of baseline in the second. There were no changes in the somatosensory evoked potential signals in either case. Post-operative neurological function was normal in both patients. Correcting the circulating haemoglobin concentration through blood product resuscitation allowed for safe correction of spinal deformity in two cases with significant bilateral MEP loss following the initial placement of rods.
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Affiliation(s)
- Brett Rocos
- Orthopaedic Surgery, Duke University, Durham, USA
| | - Ian H Wong
- Division of Orthopaedic Surgery, Toronto Western Hospital, University Health Network, Toronto, CAN
| | | | | | - Stephen J Lewis
- Division of Orthopaedic Surgery, Toronto Western Hospital, University Health Network, Toronto, CAN
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Vu C, Bush A, Choi S, Borzage M, Miao X, Nederveen AJ, Coates TD, Wood JC. Reduced global cerebral oxygen metabolic rate in sickle cell disease and chronic anemias. Am J Hematol 2021; 96:901-913. [PMID: 33891719 DOI: 10.1002/ajh.26203] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 04/19/2021] [Accepted: 04/21/2021] [Indexed: 12/18/2022]
Abstract
Anemia is the most common blood disorder in the world. In patients with chronic anemia, such as sickle cell disease or major thalassemia, cerebral blood flow increases to compensate for decreased oxygen content. However, the effects of chronic anemia on oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO2 ) are less well understood. In this study, we examined 47 sickle-cell anemia subjects (age 21.7 ± 7.1, female 45%), 27 non-sickle anemic subjects (age 25.0 ± 10.4, female 52%) and 44 healthy controls (age 26.4 ± 10.6, female 71%) using MRI metrics of brain oxygenation and flow. Phase contrast MRI was used to measure resting cerebral blood flow, while T2 -relaxation-under-spin-tagging (TRUST) MRI with disease appropriate calibrations were used to measure OEF and CMRO2 . We observed that patients with sickle cell disease and other chronic anemias have decreased OEF and CMRO2 (respectively 27.4 ± 4.1% and 3.39 ± 0.71 ml O2 /100 g/min in sickle cell disease, 30.8 ± 5.2% and 3.53 ± 0.64 ml O2 /100 g/min in other anemias) compared to controls (36.7 ± 6.0% and 4.00 ± 0.65 ml O2 /100 g/min). Impaired CMRO2 was proportional to the degree of anemia severity. We further demonstrate striking concordance of the present work with pooled historical data from patients having broad etiologies for their anemia. The reduced cerebral oxygen extraction and metabolism are consistent with emerging data demonstrating increased non-nutritive flow, or physiological shunting, in sickle cell disease patients.
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Affiliation(s)
- Chau Vu
- Department of Biomedical Engineering University of Southern California Los Angeles California USA
| | - Adam Bush
- Department of Biomedical Engineering University of Southern California Los Angeles California USA
- Department of Radiology Stanford University Stanford California USA
| | - Soyoung Choi
- Neuroscience Graduate Program University of Southern California Los Angeles California USA
| | - Matthew Borzage
- Division of Neonatology, Fetal and Neonatal Institute Children's Hospital Los Angeles Los Angeles California USA
- Department of Pediatrics, Keck School of Medicine University of Southern California Los Angeles California USA
| | - Xin Miao
- Department of Biomedical Engineering University of Southern California Los Angeles California USA
| | - Aart J. Nederveen
- University of Amsterdam, Amsterdam UMC, Radiology and Nuclear Medicine Amsterdam The Netherlands
| | - Thomas D. Coates
- Division of Hematology‐Oncology, Department of Pediatrics Children's Hospital Los Angeles Los Angeles California USA
- Departments of Pediatrics and Pathology, Keck School of Medicine University of Southern California Los Angeles California USA
| | - John C. Wood
- Department of Biomedical Engineering University of Southern California Los Angeles California USA
- Division of Cardiology, Departments of Pediatrics and Radiology Children's Hospital Los Angeles Los Angeles California USA
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5
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Wang L, Pei F, Wu J, Ouyang B, Guan X. Kidney Injury in a Hemodilution Model of Hemorrhagic Shock and Fluid Resuscitation. Am J Med Sci 2021; 362:506-511. [PMID: 34116049 DOI: 10.1016/j.amjms.2021.06.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 03/01/2021] [Accepted: 06/04/2021] [Indexed: 11/18/2022]
Abstract
BACKGROUND Fluid therapy is indispensable in treating patients with hemorrhagic shock. However, fluid overload correlates with kidney injury in patients with hemorrhagic shock. We hypothesized that hemodilution after fluid treatment contributes to the kidney injury. METHODS An animal model was established to mimic different severity of hemodilution, through resuscitating hemorrhagic shock with mixture of blood and lactated Ringer's solution (LR) in different ratios. A total of 20 rats were divided into the following four groups, the Sham group, Mild group, Moderate group, and Severe group. In the Sham group, rats were anesthetized and catheterized only. In the other three groups, shock was induced by extracting 40% of the estimated circulating blood. One hour later, rats were resuscitated with a mixture of blood and LR with ratio 1:0 in the Mild group, 0.5:0.5 in the Moderate group, and 0:1 in the Severe group. The histology of the kidneys was observed with hematoxylin and eosin (HE) staining. The mitochondria membrane potential ψ and adenosine triphosphate (ATP) production of the kidneys were measured. The serum creatinine (SCr) and blood urine nitrogen (BUN) were measured. RESULTS Renal tubular lumina dilation and mild interstitial edema occurred in the Mild group with HE staining. Proximal convoluted tubule damage, including tubular casts, narrow renal tubular lumina, and interstitial edema occurred in the Moderate group and Severe group. Mitochondrial JC-1 and ATP production decreased as hemodilution progressed. SCr and BUN increased in the Moderate group and Severe group. CONCLUSIONS The hemodilution post hemorrhagic shock and fluid resuscitation led to kidney injury.
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Affiliation(s)
- Luhao Wang
- Department of Critical Care Medicine, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, PR China; Key Laboratory on Assisted Circulation, Ministry of Health, Guangzhou 510080, PR China
| | - Fei Pei
- Department of Critical Care Medicine, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, PR China
| | - Jianfeng Wu
- Department of Critical Care Medicine, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, PR China
| | - Bin Ouyang
- Department of Critical Care Medicine, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, PR China.
| | - Xiangdong Guan
- Department of Critical Care Medicine, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, PR China.
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Møller A, Wetterslev J, Shahidi S, Hellemann D, Secher NH, Pedersen OB, Marcussen KV, Ramsing BGU, Mortensen A, Nielsen HB. Effect of low vs high haemoglobin transfusion trigger on cardiac output in patients undergoing elective vascular surgery: Post-hoc analysis of a randomized trial. Acta Anaesthesiol Scand 2021; 65:302-312. [PMID: 33141936 DOI: 10.1111/aas.13733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 10/06/2020] [Accepted: 10/07/2020] [Indexed: 12/01/2022]
Abstract
BACKGROUND During vascular surgery, restricted red-cell transfusion reduces frontal lobe oxygen (ScO2 ) saturation as determined by near-infrared spectroscopy. We evaluated whether inadequate increase in cardiac output (CO) following haemodilution explains reduction in ScO2 . METHODS This is a post-hoc analysis of data from the Transfusion in Vascular surgery (TV) Trial where patients were randomized on haemoglobin drop below 9.7 g/dL to red-cell transfusion at haemoglobin below 8.0 (low-trigger) vs 9.7 g/dL (high-trigger). Fluid administration was guided by optimizing stroke volume. We compared mean intraoperative levels of CO, haemoglobin, oxygen delivery, and CO at nadir ScO2 with linear regression adjusted for age, operation type and baseline. Data for 46 patients randomized before end of surgery were included for analysis. RESULTS The low-trigger resulted in a 7.1% lower mean intraoperative haemoglobin level (mean difference, -0.74 g/dL; P < .001) and reduced volume of red-cell transfused (median [inter-quartile range], 0 [0-300] vs 450 mL [300-675]; P < .001) compared with the high-trigger group. Mean CO during surgery was numerically 7.3% higher in the low-trigger compared with the high-trigger group (mean difference, 0.36 L/min; 95% confidence interval (CI.95), -0.05 to 0.78; P = .092; n = 42). At the nadir ScO2 -level, CO was 11.9% higher in the low-trigger group (mean difference, 0.58 L/min; CI.95, 0.10-1.07; P = .024). No difference in oxygen delivery was detected between trial groups (MD, 1.39 dLO2 /min; CI.95, -6.16 to 8.93; P = .721). CONCLUSION Vascular surgical patients exposed to restrictive RBC transfusion elicit the expected increase in CO making it unlikely that their potentially limited cardiac capacity explains the associated ScO2 decrease.
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Affiliation(s)
- Anders Møller
- Department of Anaesthesia and Intensive care Næstved‐Slagelse‐Ringsted Slagelse Hospital Slagelse Denmark
| | - Jørn Wetterslev
- Copenhagen Trial Unit Centre for Clinical Intervention Research, Rigshospitalet Copenhagen Denmark
| | - Saeid Shahidi
- Department of Cardiology and Vascular Surgery Zealand University Hospital Roskilde Roskilde Denmark
| | - Dorthe Hellemann
- Department of Anaesthesia and Intensive care Næstved‐Slagelse‐Ringsted Slagelse Hospital Slagelse Denmark
| | - Niels H. Secher
- Department of Anaesthesia, Rigshospitalet University of Copenhagen Copenhagen Denmark
| | - Ole B. Pedersen
- Department of Clinical Immunology Næstved Hospital Nastved Denmark
| | - Klaus V. Marcussen
- Department of Anaesthesia and Intensive care Næstved‐Slagelse‐Ringsted Slagelse Hospital Slagelse Denmark
| | - Benedicte G. U. Ramsing
- Department of Anaesthesia and Intensive care Næstved‐Slagelse‐Ringsted Slagelse Hospital Slagelse Denmark
| | - Anette Mortensen
- Department of Anaesthesia and Intensive care Næstved‐Slagelse‐Ringsted Slagelse Hospital Slagelse Denmark
| | - Henning B. Nielsen
- Department of Anaesthesia Zealand University Hospital Roskilde Roskilde Denmark
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Abrahamson JR, Read A, Chin K, Mistry N, Joo H, Desjardins JF, Liu E, Thai K, Wilson DF, Vinogradov SA, Maynes JT, Gilbert RE, Connelly KA, Baker AJ, Mazer CD, Hare GMT. Renal tissue Po2sensing during acute hemodilution is dependent on the diluent. Am J Physiol Regul Integr Comp Physiol 2020; 318:R799-R812. [DOI: 10.1152/ajpregu.00323.2019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Sensing changes in blood oxygen content ([Formula: see text]) is an important physiological role of the kidney; however, the mechanism(s) by which the kidneys sense and respond to changes in [Formula: see text] are incompletely understood. Accurate measurements of kidney tissue oxygen tension ([Formula: see text]) may increase our understanding of renal oxygen-sensing mechanisms and could inform decisions regarding the optimal fluid for intravascular volume resuscitation to maintain renal perfusion. In some clinical settings, starch solution may be nephrotoxic, possibly due to inadequacy of tissue oxygen delivery. We hypothesized that hemodilution with starch colloid solutions would reduce [Formula: see text] to a more severe degree than other diluents. Anesthetized Sprague-Dawley rats ( n = 77) were randomized to undergo hemodilution with either colloid (6% hydroxyethyl starch or 5% albumin), crystalloid (0.9% saline), or a sham procedure (control) ( n = 13–18 rats/group). Data were analyzed by ANOVA with significance assigned at P < 0.05. After hemodilution, mean arterial pressure (MAP) decreased marginally in all groups, while hemoglobin (Hb) and [Formula: see text] decreased in proportion to the degree of hemodilution. Cardiac output was maintained in all groups after hemodilution. [Formula: see text] decreased in proportion to the reduction in Hb in all treatment groups. At comparably reduced Hb, and maintained arterial oxygen values, hemodilution with starch resulted in larger decreases in [Formula: see text] relative to animals hemodiluted with albumin or saline ( P < 0.008). Renal medullary erythropoietin (EPO) mRNA levels increased more prominently, relative to other hypoxia-regulated molecules (GLUT-1, GAPDH, and VEGF). Our data demonstrate that the kidney acts as a biosensor of reduced [Formula: see text] following hemodilution and that [Formula: see text] may provide a quantitative signal for renal cellular responsiveness to acute anemia. Evidence of a more severe reduction in [Formula: see text] following hemodilution with starch colloid solution suggests that tissue hypoxia may contribute to starch induced renal toxicity.
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Affiliation(s)
- Jessica R. Abrahamson
- Department of Anesthesia, St. Michael’s Hospital, University of Toronto, Toronto, Ontario, Canada
| | - Austin Read
- Department of Anesthesia, St. Michael’s Hospital, University of Toronto, Toronto, Ontario, Canada
| | - Kyle Chin
- Department of Anesthesia, St. Michael’s Hospital, University of Toronto, Toronto, Ontario, Canada
| | - Nikhil Mistry
- Department of Anesthesia, St. Michael’s Hospital, University of Toronto, Toronto, Ontario, Canada
- Institute of Medical Science, University of Toronto, Ontario, Canada
| | - Hannah Joo
- Department of Anesthesia, St. Michael’s Hospital, University of Toronto, Toronto, Ontario, Canada
| | - Jean-Francois Desjardins
- Keenan Research Centre for Biomedical Science in the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada
| | - Elaine Liu
- Department of Anesthesia, St. Michael’s Hospital, University of Toronto, Toronto, Ontario, Canada
| | - Kerri Thai
- Keenan Research Centre for Biomedical Science in the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada
| | - David F. Wilson
- Department of Biochemistry and Biophysics, School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Sergei A. Vinogradov
- Department of Biochemistry and Biophysics, School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Jason T. Maynes
- Department of Anesthesia and Pain Medicine, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Richard E. Gilbert
- Keenan Research Centre for Biomedical Science in the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada
- Department of Medicine, Division of Endocrinology, St. Michael's Hospital, University of Toronto, Toronto, Ontario, Canada
| | - Kim A. Connelly
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- Keenan Research Centre for Biomedical Science in the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada
- Department of Medicine, Division of Cardiology, St. Michael's Hospital, University of Toronto, Toronto, Ontario, Canada
| | - Andrew J. Baker
- Department of Anesthesia, St. Michael’s Hospital, University of Toronto, Toronto, Ontario, Canada
- Keenan Research Centre for Biomedical Science in the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada
- Institute of Medical Science, University of Toronto, Ontario, Canada
| | - C. David Mazer
- Department of Anesthesia, St. Michael’s Hospital, University of Toronto, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- Keenan Research Centre for Biomedical Science in the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada
- Institute of Medical Science, University of Toronto, Ontario, Canada
| | - Gregory M. T. Hare
- Department of Anesthesia, St. Michael’s Hospital, University of Toronto, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- Keenan Research Centre for Biomedical Science in the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada
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8
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Low vs high hemoglobin trigger for transfusion in vascular surgery: a randomized clinical feasibility trial. Blood 2019; 133:2639-2650. [DOI: 10.1182/blood-2018-10-877530] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 03/04/2019] [Indexed: 01/28/2023] Open
Abstract
Abstract
Current guidelines advocate to limit red blood cell (RBC) transfusion during surgery, but the feasibility and safety of such a strategy remain unclear, as the majority of evidence is based on postoperatively stable patients. We assessed the effects of a protocol aiming to restrict RBC transfusion throughout hospitalization for vascular surgery. Fifty-eight patients scheduled for lower limb bypass or open abdominal aortic aneurysm repair were randomly assigned, on hemoglobin drop below 9.7 g/dL, to either a low-trigger (hemoglobin < 8.0 g/dL) or a high-trigger (hemoglobin < 9.7 g/dL) group for RBC transfusion. Near-infrared spectroscopy assessed intraoperative oxygen desaturation in brain and muscle. Explorative outcomes included nationwide registry data on death and major vascular complications. The primary outcome, mean hemoglobin within 15 days of surgery, was significantly lower in the low-trigger group, at 9.46 vs 10.33 g/dL in the high-trigger group (mean difference, −0.87 g/dL; P = .022), as were units of RBCs transfused (median [interquartile range (IQR)], 1 [0-2] vs 3 [2-6]; P = .0015). Although the duration and magnitude of cerebral oxygen desaturation increased in the low-trigger group (median [IQR], 421 [42-888] vs 127 [11-331] minutes × %; P = .0036), muscle oxygenation was unaffected. The low-trigger group associated to a higher rate of death or major vascular complications (19/29 vs 8/29; hazard ratio, 3.20; P = .006) and fewer days alive outside the hospital within 90 days (median [IQR], 76 [67-82] vs 82 [76-84] days; P = .049). In conclusion, a perioperative protocol restricting RBC transfusion successfully separated hemoglobin levels and RBC units transfused. Exploratory outcomes suggested potential harm with the low-trigger group and warrant further trials before such a strategy is universally adopted. This trial was registered at www.clinicaltrials.gov as #NCT02465125.
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