1
|
Karlsen H, Strand-Amundsen RJ, Skåre C, Eriksen M, Skulberg VM, Sunde K, Tønnessen TI, Olasveengen TM. Cerebral perfusion and metabolism with mild hypercapnia vs. normocapnia in a porcine post cardiac arrest model with and without targeted temperature management. Resusc Plus 2024; 18:100604. [PMID: 38510376 PMCID: PMC10950799 DOI: 10.1016/j.resplu.2024.100604] [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] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 02/15/2024] [Accepted: 03/03/2024] [Indexed: 03/22/2024] Open
Abstract
Aim To determine whether targeting mild hypercapnia (PaCO2 7 kPa) would yield improved cerebral blood flow and metabolism compared to normocapnia (PaCO2 5 kPa) with and without targeted temperature management to 33 °C (TTM33) in a porcine post-cardiac arrest model. Methods 39 pigs were resuscitated after 10 minutes of cardiac arrest using cardiopulmonary bypass and randomised to TTM33 or no-TTM, and hypercapnia or normocapnia. TTM33 was managed with intravasal cooling. Animals were stabilized for 30 minutes followed by a two-hour intervention period. Hemodynamic parameters were measured continuously, and neuromonitoring included intracranial pressure (ICP), pressure reactivity index, cerebral blood flow, brain-tissue pCO2 and microdialysis. Measurements are reported as proportion of baseline, and areas under the curve during the 120 min intervention period were compared. Results Hypercapnia increased cerebral flow in both TTM33 and no-TTM groups, but also increased ICP (199% vs. 183% of baseline, p = 0.018) and reduced cerebral perfusion pressure (70% vs. 84% of baseline, p < 0.001) in no-TTM animals. Cerebral lactate (196% vs. 297% of baseline, p < 0.001), pyruvate (118% vs. 152% of baseline, p < 0.001), glycerol and lactate/pyruvate ratios were lower with hypercapnia in the TTM33 group, but only pyruvate (133% vs. 150% of baseline, p = 0.002) was lower with hypercapnia among no-TTM animals. Conclusion In this porcine post-arrest model, hypercapnia led to increased cerebral flow both with and without hypothermia, but also increased ICP and reduced cerebral perfusion pressure in no-TTM animals. The effects of hypercapnia were different with and without TTM.(Institutional protocol number: FOTS, id 14931).
Collapse
Affiliation(s)
- Hilde Karlsen
- Department of Research and Development and Institute for Experimental Medical Research, Oslo University Hospital, Norway
- Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | | | - Christiane Skåre
- Department of Anesthesia and Intensive Care Medicine, Oslo University Hospital, Oslo, Norway
- University of Oslo, Oslo, Norway
| | - Morten Eriksen
- Institute for Experimental Medical Research, Oslo University Hospital, Oslo, Norway
| | - Vidar M Skulberg
- Institute for Experimental Medical Research, Oslo University Hospital, Oslo, Norway
| | - Kjetil Sunde
- Institute of Clinical Medicine, University of Oslo, Oslo, Norway
- Department of Anesthesia and Intensive Care Medicine, Oslo University Hospital, Oslo, Norway
| | - Tor Inge Tønnessen
- Institute of Clinical Medicine, University of Oslo, Oslo, Norway
- Department of Anesthesia and Intensive Care Medicine, Oslo University Hospital, Oslo, Norway
| | - Theresa M Olasveengen
- Institute of Clinical Medicine, University of Oslo, Oslo, Norway
- Department of Anesthesia and Intensive Care Medicine, Oslo University Hospital, Oslo, Norway
| |
Collapse
|
2
|
Skåre C, Karlsen H, Strand-Amundsen RJ, Eriksen M, Skulberg VM, Sunde K, Tønnessen TI, Olasveengen TM. Cerebral perfusion and metabolism with mean arterial pressure 90 vs. 60 mmHg in a porcine post cardiac arrest model with and without targeted temperature management. Resuscitation 2021; 167:251-260. [PMID: 34166747 DOI: 10.1016/j.resuscitation.2021.06.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Revised: 06/07/2021] [Accepted: 06/17/2021] [Indexed: 12/11/2022]
Abstract
AIM To determine whether targeting a mean arterial pressure of 90 mmHg (MAP90) would yield improved cerebral blood flow and less ischaemia compared to MAP 60 mmHg (MAP60) with and without targeted temperature management at 33 °C (TTM33) in a porcine post-cardiac arrest model. METHODS After 10 min of cardiac arrest, 41 swine of either sex were resuscitated until return of spontaneous circulation (ROSC). They were randomised to TTM33 or no-TTM, and MAP60 or MAP90; yielding four groups. Temperatures were managed with intravasal cooling and blood pressure targets with noradrenaline, vasopressin and nitroprusside, as appropriate. After 30 min of stabilisation, animals were observed for two hours. Cerebral perfusion pressure (CPP), cerebral blood flow (CBF), pressure reactivity index (PRx), brain tissue pCO2 (PbtCO2) and tissue intermediary metabolites were measured continuously and compared using mixed models. RESULTS Animals randomised to MAP90 had higher CPP (p < 0.001 for both no-TTM and TTM33) and CBF (no-TTM, p < 0.03; TH, p < 0.001) compared to MAP60 during the 150 min observational period post-ROSC. We also observed higher lactate and pyruvate in MAP60 irrespective of temperature, but no significant differences in PbtCO2 and lactate/pyruvate-ratio. We found lower PRx (indicating more intact autoregulation) in MAP90 vs. MAP60 (no-TTM, p = 0.04; TTM33, p = 0.03). CONCLUSION In this porcine cardiac arrest model, targeting MAP90 led to better cerebral perfusion and more intact autoregulation, but without clear differences in ischaemic markers, compared to MAP60. INSTITUTIONAL PROTOCOL NUMBER FOTS, id 8442.
Collapse
Affiliation(s)
- Christiane Skåre
- Norwegian National Advisory Unit for Prehospital Emergency Care (NAKOS), Oslo, Norway; Department of Anaesthesiology, Oslo University Hospital, Oslo, Norway; Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
| | - Hilde Karlsen
- Department of Research and Development and Institute for Experimental Medical Research, Oslo University Hospital, Oslo, Norway
| | | | - Morten Eriksen
- Institute for Experimental Medical Research, Oslo University Hospital, Oslo, Norway
| | - Vidar M Skulberg
- Institute for Experimental Medical Research, Oslo University Hospital, Oslo, Norway
| | - Kjetil Sunde
- Department of Anaesthesiology, Oslo University Hospital, Oslo, Norway; Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Tor Inge Tønnessen
- Department of Anaesthesiology, Oslo University Hospital, Oslo, Norway; Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Theresa M Olasveengen
- Department of Anaesthesiology, Oslo University Hospital, Oslo, Norway; Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| |
Collapse
|
3
|
Sun X, Zhu S, Dong X, Strand-Amundsen RJ, Tonnessen TI, Yang R. Ethyl pyruvate supplemented in drinking water ameliorates experimental nonalcoholic steatohepatitis. Biomed Pharmacother 2021; 137:111392. [PMID: 33761609 DOI: 10.1016/j.biopha.2021.111392] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [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: 11/02/2020] [Revised: 01/22/2021] [Accepted: 02/10/2021] [Indexed: 02/09/2023] Open
Abstract
Inflammation and oxidative stress play a significant role in the pathogenesis of nonalcoholic steatohepatitis (NASH). Ethyl pyruvate (EP) is a novel anti-inflammatory agent and a potent reactive oxygen species (ROS) scavenger. Therefore, EP supplemented in drinking water may alleviate experimental NASH in this study (even though 0.3% of EP cannot attenuate the simple non-aggressive fatty liver). The methionine-choline-deficient (MCD) diet was given to the C57BL/6 male mice for 3 weeks to induce NASH. The NASH animals were randomized into 3 treatment groups: animals in the MCD alone group were treated with normal drinking water alone; animals in the delayed EP group were given 3% (v/v) of EP supplemented in normal drinking water, the treatment started 10 days after MCD diet feeding; animals in the early EP therapy group were treated the same as the delayed EP group except that EP treatment started the same day when MCD diet was given; the control mice were fed with normal chow and treated with normal drinking water (n = 10 for each group). Compared to MCD group with normal drinking water, early EP treatment significantly decreased serum ALT and improved NASH histopathology; delayed EP therapy only attenuated NASH in 50% (5/10) of the animals. The beneficial effects were associated with decreased hepatic TNF-a and IL-6 mRNA expression on early 5 days, inhibited NF-kB activation, reduced liver tissue malondialdehyde levels, and decreased intestinal bacterial translocation (BT). In conclusion: EP supplemented in drinking water attenuates experimental NASH.
Collapse
Affiliation(s)
- Xiujing Sun
- Department of Gastroenterology, National Clinical Research Center for Digestive Disease, Beijing Digestive Disease Center, Beijing Key Laboratory for Precancerous Lesion of Digestive Disease, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China
| | - Shengtao Zhu
- Department of Gastroenterology, National Clinical Research Center for Digestive Disease, Beijing Digestive Disease Center, Beijing Key Laboratory for Precancerous Lesion of Digestive Disease, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China
| | - Xueyu Dong
- Department of Gastroenterology, National Clinical Research Center for Digestive Disease, Beijing Digestive Disease Center, Beijing Key Laboratory for Precancerous Lesion of Digestive Disease, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China
| | - Runar J Strand-Amundsen
- Department of Clinical and Biomedical Engineering, Oslo University Hospital, 4950 Nydalen, 0424 Oslo, Norway
| | - Tor Inge Tonnessen
- Department of Emergencies and Critical Care, Oslo University Hospital, 4950 Nydalen, 0424 Oslo, Norway; Institute of Clinical Medicine, University of Oslo, 0316 Blindern, Oslo, Norway
| | - Runkuan Yang
- Department of Emergencies and Critical Care, Oslo University Hospital, 4950 Nydalen, 0424 Oslo, Norway.
| |
Collapse
|
4
|
Strand-Amundsen RJ, Tronstad C, Reims HM, Reinholt FP, Høgetveit JO, Tønnessen TI. Machine learning for intraoperative prediction of viability in ischemic small intestine. Physiol Meas 2018; 39:105011. [PMID: 30207981 DOI: 10.1088/1361-6579/aae0ea] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
OBJECTIVE Evaluation of intestinal viability is essential in surgical decision-making in patients with acute intestinal ischemia. There has been no substantial change in the mortality rate (30%-93%) of patients with acute mesenteric ischemia (AMI) since the 1980s. As the accuracy from the first laparotomy alone is 50%, the gold standard is a second-look laparotomy, increasing the accuracy to 87%-89%. This study investigates the use of machine learning to classify intestinal viability and histological grading in pig jejunum, based on multivariate time-series of bioimpedance sensor data. APPROACH We have previously used a bioimpedance sensor system to acquire electrical parameters from perfused, ischemic and reperfused pig jejunum (7 + 15 pigs) over 1-16 h of ischemia and 1-8 h of reperfusion following selected durations of ischemia. In this study we compare the accuracy of using end-point bioimpedance measurements with a feedforward neural network (FNN), versus the accuracy when using a recurrent neural network with long short-term memory units (LSTM-RNN) with bioimpedance data history over different periods of time. MAIN RESULTS Accuracies in the range of what has been reported clinically can be achieved using FNN's on a single bioimpedance measurement, and higher accuracies can be achieved when employing LSTM-RNN on a sequence of data history. SIGNIFICANCE Intraoperative bioimpedance measurements on intestine of suspect viability combined with machine learning can increase the accuracy of intraoperative assessment of intestinal viability. Increased accuracy in intraoperative assessment of intestinal viability has the potential to reduce the high mortality and morbidity rate of the patients.
Collapse
Affiliation(s)
- Runar J Strand-Amundsen
- Department of Clinical and Biomedical Engineering, Oslo University Hospital-Rikshospitalet, Postboks 4950 Nydalen, 0424 Oslo, Norway. Department of Physics, University of Oslo, Postboks 1048 Blindern, 0316 Oslo, Norway
| | | | | | | | | | | |
Collapse
|
5
|
Strand-Amundsen RJ, Reims HM, Reinholt FP, Ruud TE, Yang R, Høgetveit JO, Tønnessen TI. Ischemia/reperfusion injury in porcine intestine - Viability assessment. World J Gastroenterol 2018; 24:2009-2023. [PMID: 29760544 PMCID: PMC5949714 DOI: 10.3748/wjg.v24.i18.2009] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 04/20/2018] [Accepted: 04/23/2018] [Indexed: 02/06/2023] Open
Abstract
AIM To investigate viability assessment of segmental small bowel ischemia/reperfusion in a porcine model.
METHODS In 15 pigs, five or six 30-cm segments of jejunum were simultaneously made ischemic by clamping the mesenteric arteries and veins for 1 to 16 h. Reperfusion was initiated after different intervals of ischemia (1-8 h) and subsequently monitored for 5-15 h. The intestinal segments were regularly photographed and assessed visually and by palpation. Intraluminal lactate and glycerol concentrations were measured by microdialysis, and samples were collected for light microscopy and transmission electron microscopy. The histological changes were described and graded.
RESULTS Using light microscopy, the jejunum was considered as viable until 6 h of ischemia, while with transmission electron microscopy the ischemic muscularis propria was considered viable until 5 h of ischemia. However, following ≥ 1 h of reperfusion, only segments that had been ischemic for ≤ 3 h appeared viable, suggesting a possible upper limit for viability in the porcine mesenteric occlusion model. Although intraluminal microdialysis allowed us to closely monitor the onset and duration of ischemia and the onset of reperfusion, we were unable to find sufficient level of association between tissue viability and metabolic markers to conclude that microdialysis is clinically relevant for viability assessment. Evaluation of color and motility appears to be poor indicators of intestinal viability.
CONCLUSION Three hours of total ischemia of the small bowel followed by reperfusion appears to be the upper limit for viability in this porcine mesenteric ischemia model.
Collapse
Affiliation(s)
- Runar J Strand-Amundsen
- Department of Clinical and Biomedical Engineering, Oslo University Hospital, Oslo 0424, Norway
- Department of Physics, University of Oslo, Oslo 0316, Norway
| | - Henrik M Reims
- Department of Pathology, Oslo University Hospital, Oslo 0424, Norway
| | - Finn P Reinholt
- Department of Pathology, Oslo University Hospital, Oslo 0424, Norway
| | - Tom E Ruud
- Institute for Surgical Research, Oslo University Hospital, Oslo 0424, Norway
- Department of Surgery, Baerum Hospital, Vestre Viken Hospital Trust, Drammen 3004, Norway
| | - Runkuan Yang
- Department of Emergencies and Critical Care, Oslo University Hospital, Oslo 0424, Norway
| | - Jan O Høgetveit
- Department of Clinical and Biomedical Engineering, Oslo University Hospital, Oslo 0424, Norway
- Department of Physics, University of Oslo, Oslo 0316, Norway
| | - Tor I Tønnessen
- Department of Emergencies and Critical Care, Oslo University Hospital, Oslo 0424, Norway
- Institute of Clinical Medicine, University of Oslo, Oslo 0424, Norway
| |
Collapse
|
6
|
Strand-Amundsen RJ, Tronstad C, Kalvøy H, Ruud TE, Høgetveit JO, Martinsen ØG, Tønnessen TI. Small intestinal ischemia and reperfusion-bioimpedance measurements. Physiol Meas 2018; 39:025001. [PMID: 29303488 DOI: 10.1088/1361-6579/aaa576] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
OBJECTIVE Trans-intestinal bioimpedance measurements have previously been used to investigate changes in electrical parameters during 6 h of ischemia in the small intestine. Knowledge is lacking regarding the time course of trans-intestinal bioimpedance parameters during reperfusion. As reperfusion is an important part in the clinical treatment of intestinal ischemia, we need to know how it affects the bioimpedance measurements. APPROACH We performed bioimpedance measurements, using a two-electrode setup on selected segments of the jejunum in 15 pigs. A controlled voltage signal was applied while measuring the resulting current. In each pig, five or six 30 cm segments of the jejunum were made ischemic by clamping the mesenteric arteries and veins creating segments with ischemia from 1-16 h duration. Reperfusion was initiated at selected time intervals of ischemia, and measured for 5-15 h afterwards. MAIN RESULTS The tan δ parameter (loss tangent) was different (p < 0.016) comparing ischemic and control tissue for the duration of the experiment (16 h). Comparing the control tissue 30 cm from the ischemic area with the control tissue 60 cm from the ischemic tissue, we found that the mean tan δ amplitude in the frequency range (3900-6300 Hz) was significantly higher (p < 0.036) in the proximal control after 10 h of experiment duration. After reperfusion, the time development of tanδm (loss tangent maximum over a frequency range) amplitude and frequency overlapped and periodically increased above the tanδm in the ischemic intestine. Dependent on the ischemic duration pre-reperfusion, the initial increase in tan δ stabilizes or increases drastically over time, compared to the tan δ amplitude of the ischemic tissue. SIGNIFICANCE As during ischemia, the electrical parameters during reperfusion also follow a characteristic time-course, depending on the ischemic exposure before pre-reperfusion. The temporal changes in electrical parameters during small intestinal ischemia followed by reperfusion provides important information for assessment of tissue injury.
Collapse
Affiliation(s)
- Runar J Strand-Amundsen
- Department of Clinical and Biomedical Engineering, Oslo University Hospital-Rikshospitalet, Postboks 4950 Nydalen, 0424 Oslo, Norway. Department of Physics, University of Oslo, Postboks 1048 Blindern, 0316 Oslo, Norway
| | | | | | | | | | | | | |
Collapse
|
7
|
Strand-Amundsen RJ, Reims HM, Tronstad C, Kalvøy H, Martinsen ØG, Høgetveit JO, Ruud TE, Tønnessen TI. Ischemic small intestine—in vivoversusex vivobioimpedance measurements. Physiol Meas 2017; 38:715-728. [DOI: 10.1088/1361-6579/aa67b7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
8
|
Strand-Amundsen RJ, Tronstad C, Kalvøy H, Gundersen Y, Krohn CD, Aasen AO, Holhjem L, Reims HM, Martinsen ØG, Høgetveit JO, Ruud TE, Tønnessen TI. In vivo characterization of ischemic small intestine using bioimpedance measurements. Physiol Meas 2016; 37:257-75. [PMID: 26805916 DOI: 10.1088/0967-3334/37/2/257] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The standard clinical method for the assessment of viability in ischemic small intestine is still visual inspection and palpation. This method is non-specific and unreliable, and requires a high level of clinical experience. Consequently, viable tissue might be removed, or irreversibly damaged tissue might be left in the body, which may both slow down patient recovery. Impedance spectroscopy has been used to measure changes in electrical parameters during ischemia in various tissues. The physical changes in the tissue at the cellular and structural levels after the onset of ischemia lead to time-variant changes in the electrical properties. We aimed to investigate the use of bioimpedance measurement to assess if the tissue is ischemic, and to assess the ischemic time duration. Measurements were performed on pigs (n = 7) using a novel two-electrode setup, with a Solartron 1260/1294 impedance gain-phase analyser. After induction of anaesthesia, an ischemic model with warm, full mesenteric arterial and venous occlusion on 30 cm of the jejunum was implemented. Electrodes were placed on the serosal surface of the ischemic jejunum, applying a constant voltage, and measuring the resulting electrical admittance. As a control, measurements were done on a fully perfused part of the jejunum in the same porcine model. The changes in tan δ (dielectric parameter), measured within a 6 h period of warm, full mesenteric occlusion ischemia in seven pigs, correlates with the onset and duration of ischemia. Tan δ measured in the ischemic part of the jejunum differed significantly from the control tissue, allowing us to determine if the tissue was ischemic or not (P < 0.0001, F = (1,75.13) 188.19). We also found that we could use tan δ to predict ischemic duration. This opens up the possibility of real-time monitoring and assessment of the presence and duration of small intestinal ischemia.
Collapse
Affiliation(s)
- R J Strand-Amundsen
- Department of Clinical and Biomedical Engineering, Oslo University Hospital - Rikshospitalet, Postboks 4950 Nydalen, 0424 Oslo, Norway. Department of Physics, University of Oslo, Postboks 1048 Blindern, 0316 Oslo, Norway
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|