Tor Inge Tønnessen

• Karlsen, Hilde; Strand-Amundsen, Runar James; Skaare, Christiane; Eriksen, Morten Tandberg; Skulberg, Vidar Magne & Sunde, Kjetil [Vis alle 8 forfattere av denne artikkelen] (2024). Cerebral perfusion and metabolism with mild hypercapnia vs. normocapnia in a porcine post cardiac arrest model with and without targeted temperature management. Resuscitation Plus. ISSN 2666-5204. 18. doi: 10.1016/j.resplu.2024.100604.
• Sjøen, Gunnar Helge; Falk, Ragnhild Sørum; Hauge, Tor Hugo; Tønnessen, Tor Inge & Langesæter, Eldrid (2024). Haemodynamic effects of remifentanil during induction of general anaesthesia with propofol. A randomised trial. Acta Anaesthesiologica Scandinavica. ISSN 0001-5172. s. 1–9. doi: 10.1111/aas.14394.
• Rydenfelt, Kristina Elisabeth; Kjøsen, Gisle; Horneland, Rune; Ludviksen, Judith K; Jenssen, Trond & Line, Pål Dag [Vis alle 10 forfattere av denne artikkelen] (2023). Local Postoperative Graft Inflammation in Pancreas Transplant Patients With Early Graft Thrombosis. Transplantation direct. ISSN 2373-8731. 10(1). doi: 10.1097/TXD.0000000000001567. Fulltekst i vitenarkiv
• Sjøen, Gunnar Helge; Falk, Ragnhild Sørum; Hauge, Tor Hugo; Tønnessen, Tor Inge & Langesæter, Eldrid (2023). Hemodynamic effects of a low versus a high dose of propofol during induction of anesthesia. A randomized trial. Acta Anaesthesiologica Scandinavica. ISSN 0001-5172. doi: 10.1111/aas.14293. Fulltekst i vitenarkiv
• Rydenfelt, Kristina Elisabeth; Kjøsen, Gisle; Horneland, Rune; Ludviksen, Judith K; Jenssen, Trond & Line, Pål Dag [Vis alle 10 forfattere av denne artikkelen] (2023). Thromboinflammatory response is increased in pancreas transplant alone versus simultaneous pancreas-kidney transplantation and early pancreas graft thrombosis is associated with complement activation. Frontiers in Immunology. ISSN 1664-3224. 14. doi: 10.3389/fimmu.2023.1044444. Fulltekst i vitenarkiv
• Hou, Jie; Ness, Siri Schøne; Tschudi, Jon; O'Farrell, Marion; Veddegjerde, Rune & Martinsen, Ørjan Grøttem [Vis alle 8 forfattere av denne artikkelen] (2022). Assessment of Intestinal Ischemia–Reperfusion Injury Using Diffuse Reflectance VIS-NIR Spectroscopy and Histology. Sensors. ISSN 1424-8220. 22(23). doi: 10.3390/s22239111. Fulltekst i vitenarkiv
• Hou, Jie; Liavåg, Olav Magnus Ivar; Færden, Ida Høy; Martinsen, Ørjan Grøttem; Tønnessen, Tor Inge & Line, Pål Dag [Vis alle 10 forfattere av denne artikkelen] (2022). Utilization of dielectric properties for assessment of liver ischemia-reperfusion injury in vivo and during machine perfusion. Scientific Reports. ISSN 2045-2322. 12(1). doi: 10.1038/s41598-022-14817-3. Fulltekst i vitenarkiv
• Hou, Jie; Strand-Amundsen, Runar James; Tronstad, Christian; Tønnessen, Tor Inge; Høgetveit, Jan Olav & Martinsen, Ørjan Grøttem (2022). Small intestinal viability assessment using dielectric relaxation spectroscopy and deep learning. Scientific Reports. ISSN 2045-2322. 12(1). doi: 10.1038/s41598-022-07140-4. Fulltekst i vitenarkiv
• Rydenfelt, Kristina Elisabeth; Strand-Amundsen, Runar James; Horneland, Rune; Hødnebø, Stina; Kjøsen, Gisle & Pischke, Soeren [Vis alle 8 forfattere av denne artikkelen] (2022). Microdialysis and CO<inf>2</inf> sensors detect pancreatic ischemia in a porcine model. PLOS ONE. ISSN 1932-6203. 17(2). doi: 10.1371/journal.pone.0262848. Fulltekst i vitenarkiv
• Kjøsen, Gisle; Horneland, Rune; Nordheim, Espen; Aandahl, Einar Martin; Line, Pål Dag & Rydenfelt, Kristina Elisabeth [Vis alle 9 forfattere av denne artikkelen] (2022). Validating the US pancreas donor risk index in a Norwegian population, a retrospective observational study. Scandinavian Journal of Gastroenterology. ISSN 0036-5521. 57(3), s. 345–351. doi: 10.1080/00365521.2021.2012590. Fulltekst i vitenarkiv Vis sammendrag

  OBJECTIVES Despite advances in immunosuppression and surgical technique, pancreas transplantation is still associated with a significant graft loss rate. The Pancreas Donor Risk Index (PDRI) is a pre-transplant scoring tool derived from a US population. We sought to validate the PDRI in a Norwegian population. METHODS We retrospectively retrieved donor data for 344 pancreas transplants undertaken in Norway between 2000 and 2019, utilising the Scandiatransplant database, and matched these to the respective recipients. The PDRI score was calculated for each transplanted pancreas, these were then stratified into quintiles. The association between the PDRI quintiles and 1-year graft survival was calculated, and this was repeated for the different types of pancreas transplantation. The association between PDRI as a continuous variable, and graft survival was determined. Donor and recipient data were compared to the original US population. RESULTS The overall 1-year graft survival was 82.7%. There were no significant differences in survival between the different PDRI quintiles. When viewed as a continuous variable, increased PDRI score was not associated with decreased graft survival. Significant differences between the Norwegian and US populations were found. CONCLUSIONS When applied to a Norwegian population, the PDRI score was unable to predict 1-year graft survival.

• Strand-Amundsen, Runar James; Tronstad, Christian; Elvebakk, Ole; Martinsen, Tormod; Dybwad, Marius & Lingaas, Egil (2021). Quantification of aerosol dispersal from suspected aerosol-generating procedures. European Respiratory Journal Open Research (ERJ Open Research). ISSN 2312-0541. 7:00206-2021(4), s. 1–12. doi: 10.1183/23120541.00206-2021. Fulltekst i vitenarkiv
• Kjøsen, Gisle; Rydenfelt, Kristina Elisabeth; Horneland, Rune; Aandahl, Einar Martin; Line, Pål Dag & Dorenberg, Eric Jürgen [Vis alle 15 forfattere av denne artikkelen] (2021). Early detection of complications in pancreas transplants by microdialysis catheters, an observational feasibility study. PLOS ONE. ISSN 1932-6203. 16(3), s. 1–16. doi: 10.1371/journal.pone.0247615. Fulltekst i vitenarkiv
• Hou, Jie; Strand-Amundsen, Runar James; Hødnebø, Stina; Tønnessen, Tor Inge & Høgetveit, Jan Olav (2021). Assessing ischemic injury in human intestine ex vivo with electrical impedance spectroscopy. Journal of Electrical Bioimpedance. ISSN 1891-5469. 12(1), s. 82–88. doi: 10.2478/joeb-2021-0011. Fulltekst i vitenarkiv
• Lindholm, Espen; Bergmann, Gisli Björn; Haugaa, Håkon; Labori, Knut Jørgen; Yaqub, Sheraz & Bjørnbeth, Bjørn Atle [Vis alle 11 forfattere av denne artikkelen] (2021). Early detection of anastomotic leakage after pancreatoduodenectomy with microdialysis catheters: an observational Study. HPB. ISSN 1365-182X. 24(6), s. 901–909. doi: 10.1016/j.hpb.2021.10.020. Fulltekst i vitenarkiv Vis sammendrag

  Background Microdialysis catheters can detect focal inflammation and ischemia, and thereby have a potential for early detection of anastomotic leakages after pancreatoduodenectomy. The aim was to investigate whether microdialysis catheters placed near the pancreaticojejunostomy can detect leakage earlier than the current standard of care. Methods Thirty-five patients with a median age 69 years were included. Two microdialysis catheters were placed at the end of surgery; one at the pancreaticojejunostomy, and one at the hepaticojejunostomy. Concentrations of glucose, lactate, pyruvate, and glycerol were analyzed hourly in the microdialysate during the first 24 h, and every 2–4 h thereafter. Results Seven patients with postoperative pancreatic fistulae (POPF) had significantly higher glycerol levels (P < 0.01) in the microdialysate already in the first postoperative samples. Glycerol concentrations >400 μmol/L during the first 12 postoperative hours detected patients with POPF with a sensitivity of 100% and a specificity of 93% (P < 0.001). After 24 h, lactate and lactate-to-pyruvate ratio were significantly higher (P < 0.05) and glucose was significantly lower (P < 0.05) in patients with POPF. Conclusion High levels of glycerol in microdialysate was an early detector of POPF. The subsequent inflammation was detected as increase in lactate and lactate-to-pyruvate ratio and a decrease in glucose (NCT03627559).

• Hou, Jie; Strand-Amundsen, Runar James; Tronstad, Christian; Høgetveit, Jan Olav; Martinsen, Ørjan Grøttem & Tønnessen, Tor Inge (2021). Automatic prediction of ischemia-reperfusion injury of small intestine using convolutional neural networks: A pilot study. Sensors. ISSN 1424-8220. 21(19). doi: 10.3390/s21196691. Fulltekst i vitenarkiv
• Skaare, Christiane; Karlsen, Hilde; Strand-Amundsen, Runar James; Eriksen, Morten; Skulberg, Vidar Magne & Sunde, Kjetil [Vis alle 8 forfattere av denne artikkelen] (2021). 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. ISSN 0300-9572. s. 1–10. doi: 10.1016/j.resuscitation.2021.06.011. Fulltekst i vitenarkiv
• Hausken, John; Haugaa, Håkon; Hagness, Morten; Line, Pål-Dag; Melum, Espen & Tønnessen, Tor Inge (2021). Thoracic Epidural Analgesia for Postoperative Pain Management in Liver Transplantation: A 10-year Study on 685 Liver Transplant Recipients. Transplantation direct. ISSN 2373-8731. 7(2), s. 1–6. doi: 10.1097/TXD.0000000000001101. Fulltekst i vitenarkiv Vis sammendrag

  Background. Thoracic epidural analgesia (TEA) is not widely used for postoperative pain management in liver transplantation due to hepatic coagulopathy-related increased risk of inducing an epidural hematoma. However, an increasing number of patients are transplanted for other indications than the end-stage liver disease and without coagulopathy allowing insertion of an epidural catheter. Methods. This study is a retrospective observational single-center study of all adult patients undergoing first-time liver transplantation at Oslo University Hospital between January 1, 2008, and December 31, 2017. Data regarding patient characteristics were obtained from the Nordic liver transplant registry, medical records, and pain registration forms. Patients without coagulopathy (international normalized ratio <1.5 and platelets >100 × 109/L) were eligible for TEA. Results. Out of 685 first-time liver transplantations in a 10-year period, 327 received TEA, and 358 did not. The median Model of End-stage Liver Disease score was lower in the TEA group than in the non-TEA-group (9 versus 17, P < 0.001), and fewer patients were hospitalized preoperatively (16 versus 127, P < 0.001). The median international normalized ratio (1.1 versus 1.6, P < 0.001) and platelet count (190 versus 78, P < 0.001) were different between the TEA and non-TEA groups. There were no serious complications related to insertion or removal of the TEA catheters. Patients in the TEA group had less pain with a mean numeric rating scale at postoperative days 0–5 of 1.4 versus 1.8 (P = 0.008). Nearly 50% of the patients were prescribed opioids when discharged from hospital (non-TEA 154 versus TEA 158, P = 0.23), and there was no difference after 1 year (P = 0.718). Conclusions. Our report revealed very good pain control with both TEA and the non-TEA modality. TEA was without any serious complications like epidural hematoma or infection/abscess in selected liver transplant recipients without severe coagulopathy. Opioid prescription at hospital discharge and by 1-year follow-up did not differ between the groups.

• Sun, Xiujing; Zhu, Shengtao; Dong, Xueyu; Strand-Amundsen, Runar James; Tønnessen, Tor Inge & Yang, Runkuan (2021). Ethyl pyruvate supplemented in drinking water ameliorates experimental nonalcoholic steatohepatitis. Biomedicine & Pharmacotherapy. ISSN 0753-3322. 137, s. 1–7. doi: 10.1016/j.biopha.2021.111392. Fulltekst i vitenarkiv
• Lindholm, Espen; Ekiz, Nil & Tønnessen, Tor Inge (2021). Monitoring of patients with microdialysis following pancreaticoduodenectomy—the MINIMUM study: study protocol for a randomized controlled trial. Trials. ISSN 1745-6215. 22(1), s. 1–15. doi: 10.1186/s13063-021-05221-9. Fulltekst i vitenarkiv
• Sun, Xiujing; Zhu, Shengtao; Tønnessen, Tor Inge & Yang, Runkuan (2020). Bile is a promising gut nutrient that inhibits intestinal bacterial translocation and promotes gut motility via an interleukin-6-related pathway in an animal model of endotoxemia. Nutrition - The International Journal of Applied and Basic Nutritional Sciences. ISSN 0899-9007. doi: 10.1016/j.nut.2020.111064. Vis sammendrag

  Objectives People who are critically ill have high rates of endotoxemia that can significantly decrease bile flow and increase bile cytokines, the latter of which might worsen their condition. Bile acids are nutrient-signaling hormones that have a significant impact on gut barrier function and motility, and the gut is considered the origin of systemic inflammation. Therefore, healthy exogenous bile could be a promising gut nutrient for critical illness, so the biomedical role of bile in endotoxemia was investigated in this study. Methods Twelve rats were injected with lipopolysaccharide (LPS) and randomized into a group with sham operation) and a group with bile external drainage (n = 6 for each group); six rats with sham operation served as the control group. In addition, interleukin-6 (IL-6) knockout mice and macrophages were treated with LPS. Results Compared to the control animals, the group with LPS injection and sham operation had significantly increased levels of gut permeability, gut bacterial translocation, gut mucosal tumor necrosis factor α, IL-6 transcripts, and serum tumor necrosis factor α and IL-6. Compared to group with sham operation and LPS injection, bile external drainage (in LPS-challenged rats) increased gut bacterial translocation by 10 times, and this detrimental effect was associated with prolonged intestinal transit time, increased serum IL-6 concentration, and up-regulated gut mucosal IL-6 transcripts. Moreover, bile selectively inhibited LPS-stimulated macrophages in IL-6 release, which can activate gastrointestinal submucosal neurons to promote motility. Knocking out IL-6 significantly reduced gut bacterial translocation in endotoxemic mice. Conclusions Bile is a promising gut nutrient that inhibits gut bacterial translocation and promotes gut motility via an IL-6-related pathway in experimental endotoxemia.

• Pischke, Soeren; Hødnebø, Stina; Wester, Torjus; Haugaa, Håkon; Kvernebo, Knut & Barratt-Due, Andreas [Vis alle 7 forfattere av denne artikkelen] (2020). Intraperitoneal microdialysis detects intestinal leakage earlier than hemodynamic surveillance and systemic inflammation in a pig model. Scandinavian Journal of Gastroenterology. ISSN 0036-5521. 56(2), s. 219–227. doi: 10.1080/00365521.2020.1863459. Fulltekst i vitenarkiv
• Lipcsey, Miklos; Tenhunen, Jyrki; Pischke, Soeren; Kuitunen, Anne; Flaatten, Hans & De Geer, Lina [Vis alle 15 forfattere av denne artikkelen] (2020). Endotoxin removal in septic shock with the Alteco LPS Adsorber was safe but showed no benefit compared to placebo in the double-blind randomized controlled trial - the Asset Study. Shock. ISSN 1073-2322. 54(2), s. 224–231. doi: 10.1097/SHK.0000000000001503. Fulltekst i vitenarkiv
• Hausken, John; Fretland, Åsmund Avdem; Edwin, Bjørn; Andersen, Marit Helen; Dagenborg, Vegar Johansen & Bjørnelv, Gudrun Maria Waaler [Vis alle 10 forfattere av denne artikkelen] (2019). Intravenous patient-controlled analgesia versus thoracic epidural analgesia after open liver surgery: a prospective, randomized, controlled noninferiority trial. Annals of Surgery. ISSN 0003-4932. 270(2), s. 193–199. doi: 10.1097/SLA.0000000000003209.
• Hausken, John; Rydenfelt, Kristina Elisabeth; Horneland, Rune; Ullensvang, Kyrre; Kjøsen, Gisle & Tønnessen, Tor Inge [Vis alle 7 forfattere av denne artikkelen] (2019). First Experience With Rectus Sheath Block for Postoperative Analgesia After Pancreas Transplant: A Retrospective Observational Study. Transplantation Proceedings. ISSN 0041-1345. 51(2), s. 479–484. doi: 10.1016/j.transproceed.2019.01.065. Fulltekst i vitenarkiv
• Yang, Runkuan & Tønnessen, Tor Inge (2018). DAMPs and sterile inflammation in drug hepatotoxicity. Hepatology International. ISSN 1936-0533. 13(1), s. 42–50. doi: 10.1007/s12072-018-9911-9.
• Strand-Amundsen, Runar James; Tronstad, Christian; Reims, Henrik Mikael; Reinholt, Finn P.; Høgetveit, Jan Olav & Tønnessen, Tor Inge (2018). Machine learning for intraoperative prediction of viability in ischemic small intestine. Physiological Measurement. ISSN 0967-3334. 39(10), s. 1–16. doi: 10.1088/1361-6579/aae0ea. Fulltekst i vitenarkiv
• Stafseth, Siv Anna Ulla-Britt Karlsson; Tønnessen, Tor Inge; Diep, Lien My & Fagerström, Lisbeth (2018). Testing the reliability and validity of the Nursing Activities Score in critical care nursing. Journal of Nursing Measurement. ISSN 1061-3749. 26(1), s. 142–162. doi: 10.1891/1061-3749.26.1.142. Fulltekst i vitenarkiv Vis sammendrag

  Background and Purpose: The purpose of this study was to test the reliability and validity of the conceptual model of critical care nursing using the Nursing Activities Score (NAS) for intensive care unit (ICU) patients. Methods: An observational study conducted in 2011 using the NAS scores of 219 patients in Norway. The inter-rater reliability (IRR) was tested by parallel classifications. The validity was explored by an exploratory factor analysis (EFA) and a confirmatory factor analysis (CFA) as the measurement models in the structural equation model. Results: Within the paired ratings the Spearman's correlation coefficient was 0.39. The EFA results explained 77% of the variance with six factors. The reduced CFA model resulted in a three-factor model: relationship, prevention and treatment. Conclusion: The findings supported the IRR and construct validity of the conceptual model of the NAS.

• Holhjem, Lars; Strand-Amundsen, Runar James; Aasmundtveit, Knut Eilif & Tønnessen, Tor Inge (2018). Stability of Laser-Patterned Electrode Compositions. IEEE Transactions on Components, Packaging, and Manufacturing Technology. ISSN 2156-3950. 8(9), s. 1517–1523. doi: 10.1109/TCPMT.2018.2863221. Vis sammendrag

  Electrodes can be created with maskless metallization of Cu tracks ablated with laser direct structuring on the surface of a Cu-liquid-crystal polymer composite. The composition of these electrodes may not be stable in a corrosive environment, such as an electrolyte, which is needed to use these structures as conductometric sensors. We have evaluated five different electrode compositions in a low corrosive environment and found electroless palladium-immersion gold to be the most stable. The other electrode compositions have pinholes in the metal layers enabling metal migration and local galvanic corrosion. We also investigate the effect of CO 2 snow jet cleaning on the electrodes and its relationship with the electrode composition stability. The CO 2 snow jet cleaning leads to smoother electrode surfaces. A smooth electrode surface will have fewer imperfections and therefore less metal migration and galvanic corrosion.

• Stafseth, Siv Anna Ulla-Britt Karlsson; Tønnessen, Tor Inge & Fagerström, Lisbeth (2018). Association between patient classification systems and nurse staffing costs in intensive care units: An exploratory study. Intensive & Critical Care Nursing. ISSN 0964-3397. 45, s. 78–84. doi: 10.1016/j.iccn.2018.01.007. Vis sammendrag

  Objectives Nurse staffing costs represent approximately 60% of total intensive care unit costs. In order to analyse resource allocation in intensive care, we examined the association between nurse staffing costs and two patient classification systems: the nursing activities score (NAS) and nine equivalents of nursing manpower use score (NEMS). Research methodology/design A retrospective descriptive correlational analysis of nurse staffing costs and data of 6390 patients extracted from a data warehouse. Setting Three intensive care units in a university hospital and one in a regional hospital in Norway. Main outcome measures Nurse staffing costs, NAS and NEMS. Results For merged data from all units, the NAS was more strongly correlated with monthly nurse staffing costs than was the NEMS. On separate analyses of each ICU, correlations were present for the NAS on basic costs and external overtime costs but were not significant. The annual mean nurse staffing cost for 1% of NAS was 20.9–23.1 euros in the units, which was comparable to 53.3–81.5 euros for 1 NEMS point. Conclusion A significant association was found between monthly costs, NAS, and NEMS. Cost of care should be based on individual patients’ nursing care needs. The NAS makes nurses’ workload visible and may be a helpful classification system in future planning and budgeting of intensive care resources.

• Strand-Amundsen, Runar James; Reims, Henrik Mikael; Reinholt, Finn P.; Ruud, Tom Erik; Yang, Runkuan & Høgetveit, Jan Olav [Vis alle 7 forfattere av denne artikkelen] (2018). Ischemia/reperfusion injury in porcine intestine - Viability assessment. World Journal of Gastroenterology (WJG). ISSN 1007-9327. 24(18), s. 2009–2023. doi: 10.3748/wjg.v24.i18.2009.
• Strand-Amundsen, Runar James; Tronstad, Christian; Kalvøy, Håvard; Ruud, Tom Erik; Høgetveit, Jan Olav & Martinsen, Ørjan Grøttem [Vis alle 7 forfattere av denne artikkelen] (2018). Small intestinal ischemia and reperfusion - Bioimpedance measurements. Physiological Measurement. ISSN 0967-3334. 39(2). doi: 10.1088/1361-6579/aaa576. Fulltekst i vitenarkiv
• Yang, Runkuan; Zhu, Shengtao; Pischke, Søren Erik; Haugaa, Håkon; Zou, Xiaoping & Tønnessen, Tor Inge (2018). Bile and circulating HMGB1 contributes to systemic inflammation in obstructive jaundice. Journal of Surgical Research. ISSN 0022-4804. 228, s. 14–19. doi: 10.1016/j.jss.2018.02.049.
• Fretland, Åsmund Avdem; Dagenborg, Vegar Johansen; Bjørnelv, Gudrun Maria Waaler; Kazaryan, Airazat M.; Kristiansen, Ronny & Fagerland, Morten [Vis alle 17 forfattere av denne artikkelen] (2018). Laparoscopic Versus Open Resection for Colorectal Liver Metastases: The OSLO-COMET Randomized Controlled Trial . Annals of Surgery. ISSN 0003-4932. 267(2), s. 199–207. doi: 10.1097/SLA.0000000000002353. Fulltekst i vitenarkiv Vis sammendrag

  Objective: To perform the first randomized controlled trial to compare laparoscopic and open liver resection. Summary Background Data: Laparoscopic liver resection is increasingly used for the surgical treatment of liver tumors.However, high-level evidence to conclude that laparoscopic liver resection is superior to open liver resection is lacking. Methods: Explanatory, assessor-blinded, single center, randomized superiority trial recruiting patients from Oslo University Hospital, Oslo, Norway from February 2012 to January 2016. A total of 280 patients with resectable liver metastases from colorectal cancer were randomly assigned to undergo laparoscopic (n ¼ 133) or open (n ¼ 147) parenchyma-sparing liver resection. The primary outcome was postoperative complications within 30 days (Accordion grade 2 or higher). Secondary outcomes included cost-effectiveness, postoperative hospital stay, blood loss, operation time, and resection margins. Results: The postoperative complication rate was 19% in the laparoscopicsurgery group and 31% in the open-surgery group (12 percentage points difference [95% confidence interval 1.67–21.8; P ¼ 0.021]). The postoperative hospital stay was shorter for laparoscopic surgery (53 vs 96 hours, P < 0.001), whereas there were no differences in blood loss, operation time, and resection margins. Mortality at 90 days did not differ significantly from the laparoscopic group (0 patients) to the open group (1 patient). In a 4-month perspective, the costs were equal, whereas patients in the laparoscopicsurgery group gained 0.011 quality-adjusted life years compared to patients in the open-surgery group (P ¼ 0.001). Conclusions: In patients undergoing parenchyma-sparing liver resection for colorectal metastases, laparoscopic surgery was associated with significantly less postoperative complications compared to open surgery. Laparoscopic resection was cost-effective compared to open resection with a 67% probability. The rate of free resection margins was the same in both groups. Our results support the continued implementation of laparoscopic liver resection. Keywords: colorectal liver metastases, cost and cost analysis, hepatectomy, laparoscopic, laparoscopy, liver resection, minimally invasive surgery, parenchyma-sparing liver surgery, randomized clinical trial, randomized controlled trial

• Yang, Runkuan; Tenhunen, Jyrki & Tønnessen, Tor Inge (2017). HMGB1 and histones play a significant role in inducing systemic inflammation and multiple organ dysfunctions in severe acute pancreatitis. International Journal of Inflammation. ISSN 2090-8040. 2017:1817564, s. 1–6. doi: 10.1155/2017/1817564.
• Strand-Amundsen, Runar James; Reims, Henrik Mikael; Tronstad, Christian; Kalvøy, Håvard; Martinsen, Ørjan Grøttem & Høgetveit, Jan Olav [Vis alle 8 forfattere av denne artikkelen] (2017). Ischemic small intestine - In vivo versus ex vivo bioimpedance measurements. Physiological Measurement. ISSN 0967-3334. 38(5), s. 715–728. doi: 10.1088/1361-6579/aa67b7.
• Yang, Runkuan; Zou, Xiaoping; Tenhunen, Jyrki & Tønnessen, Tor Inge (2017). HMGB1 and Extracellular Histones Significantly Contribute to Systemic Inflammation and Multiple Organ Failure in Acute Liver Failure. Mediators of Inflammation. ISSN 0962-9351. 2017:5928078, s. 1–6. doi: 10.1155/2017/5928078.
• Pischke, Søren Erik; Gustavsen, Alice; Orrem, Hilde Lang; Egge, Kjetil Hagene; Courivaud, Fredric A A & Fontenelle, Hugues [Vis alle 15 forfattere av denne artikkelen] (2017). Complement factor 5 blockade reduces porcine myocardial infarction size and improves immediate cardiac function. Basic Research in Cardiology. ISSN 0300-8428. 112:20(3). doi: 10.1007/s00395-017-0610-9. Fulltekst i vitenarkiv
• Yang, Runkuan; Zhu, Shengtao & Tønnessen, Tor Inge (2016). Ethyl pyruvate is a novel anti-inflammatory agent to treat multiple inflammatory organ injuries. Journal of Inflammation. ISSN 1476-9255. 13(1). doi: 10.1186/s12950-016-0144-1.
• Lipcsey, Miklos; Tenhunen, Jyrki; Sjölin, Jan; Frithiof, Robert; Bendel, Stepani & Flaatten, Hans [Vis alle 10 forfattere av denne artikkelen] (2016). Abdominal Septic Shock – Endotoxin Adsorption Treatment (ASSET) – endotoxin removal in abdominal and urogenital septic shock with the Alteco® LPS Adsorber: study protocol for a double-blinded, randomized placebo-controlled trial. Trials. ISSN 1745-6215. 17:587, s. 1–10. doi: 10.1186/s13063-016-1723-4.
• Strand-Amundsen, Runar James; Tronstad, Christian; Kalvøy, Håvard; Gundersen, Yngvar; Krohn, Claus Danckert & Aasen, Ansgar Oddne [Vis alle 11 forfattere av denne artikkelen] (2016). In vivo characterization of ischemic small intestine using bioimpedance measurements. Physiological Measurement. ISSN 0967-3334. 37(2), s. 257–275. doi: 10.1088/0967-3334/37/2/257. Vis sammendrag

  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.

• Khan, Faraz Hameed; Pharo, Anne Margrethe; Lindstad, Julie Katrine; Mollnes, Tom Eirik; Tønnessen, Tor Inge & Pischke, Søren Erik (2015). Effect of Perfusion Fluids on Recovery of Inflammatory Mediators in Microdialysis. Scandinavian Journal of Immunology. ISSN 0300-9475. 82(5), s. 467–475. doi: 10.1111/sji.12332.
• Haugaa, Håkon; Gómez, Hernando; Maberry, Donald R.; Holder, Andre; Ogundele, Olufunmilayo & Quintero, Ana Maria B. [Vis alle 14 forfattere av denne artikkelen] (2015). Effects of inhalation of low-dose nitrite or carbon monoxide on post-reperfusion mitochondrial function and tissue injury in hemorrhagic shock swine. Critical Care. ISSN 1364-8535. 19:184. doi: 10.1186/s13054-015-0903-z.
• Hyler, Stefan; Pischke, Søren Erik; Halvorsen, Per Steinar; Espinoza, Andreas Westenvik; Bergsland, Jacob & Tønnessen, Tor Inge [Vis alle 8 forfattere av denne artikkelen] (2015). Continuous monitoring of regional function by a miniaturized ultrasound transducer allows early quantification of low-grade myocardial ischemia. Journal of the American Society of Echocardiography. ISSN 0894-7317. 28(4), s. 486–494. doi: 10.1016/j.echo.2014.12.014.
• Fretland, Åsmund Avdem; Kazaryan, Airazat M.; Bjørnbeth, Bjørn Atle; Flatmark, Kjersti; Andersen, Marit Helen & Tønnessen, Tor Inge [Vis alle 11 forfattere av denne artikkelen] (2015). Open versus laparoscopic liver resection for colorectal liver metastases (the Oslo-CoMet study): study protocol for a randomized controlled trial. Trials. ISSN 1745-6215. 16:73. doi: 10.1186/s13063-015-0577-5. Fulltekst i vitenarkiv
• Pischke, Søren Erik; Hyler, Stefan; Tronstad, Christian; Bergsland, Jacob; Fosse, Erik & Halvorsen, Per Steinar [Vis alle 8 forfattere av denne artikkelen] (2015). Myocardial tissue CO2 tension detects coronary blood flow reduction after coronary artery bypass in real-time. British Journal of Anaesthesia. ISSN 0007-0912. 114(3), s. 414–422. doi: 10.1093/bja/aeu381.
• Holhjem, Lars; Strand-Amundsen, Runar; Aasmundtveit, Knut Eilif & Tønnessen, Tor Inge (2014). Electrode compositions for laser patterned conductometric sensors, Electronics System-Integration Technology Conference (ESTC), 2014, Helsinki. 16-18 Sept. 2014. IEEE conference proceedings. ISSN 978-1-4799-4025-7. doi: 10.1109/ESTC.2014.6962782. Vis sammendrag

  An electrode created with maskless metallization of Cu tracks ablated with laser direct structuring on a liquid crystal polymer can never achieve a quality comparable to sputtered layers on silicon, but has the advantage of being molded into complex 3D structures. As these electrodes on molded interconnected devices can function as conductometric sensors capable of detecting ion changes in a liquid it is of high interest to characterize a variety of metal systems in terms of electrode performance. The sensor models Cu|Ni-P|Pd|Au, Cu|Ni-P|Au, Cu|Pd|Au, Cu|Pd and Cu|Ag were tested for stability in an aqueous environment, and for sensitivity to detect a change in the conductance of a liquid environment. For both tests, the Cu|Pd|Au electrode had the most stable impedance and sensitivity, with the smallest variance (10 samples of each electrode composition pair tested). Inspection by Scanning Electron Microscope with Energy Dispersive X-ray spectroscopy explained this result.

• Haugaa, Håkon; Taraldsrud, Eli; Nyrerød, Hans Christian; Tønnessen, Tor Inge; Foss, Aksel & Solheim, Bjarte G. (2014). Low incidence of hyperfibrinolysis and thromboembolism in 195 primary liver transplantations transfused with solvent/detergent-treated plasma. Clinical Medicine & Research. ISSN 1539-4182. 12(1-2), s. 27–32. doi: 10.3121/cmr.2013.1168.
• Yang, Runkuan; Zou, Xiaoping; Tenhunen, Jyrki; Zhu, Shengtao; Kajander, Henri & Koskinen, Marja-Leena [Vis alle 7 forfattere av denne artikkelen] (2014). HMGB1 neutralization is associated with bacterial translocation during acetaminophen hepatotoxicity. BMC Gastroenterology. ISSN 1471-230X. 14(1). doi: 10.1186/1471-230X-14-66.
• Sokolov, Andrey; Hellerud, Bernt C; Tønnessen, Tor Inge; Johannessen, Erik & Mollnes, Tom Eirik (2013). Activation of coagulation and platelets by candidate membranes of implantable devices in a whole blood model without soluble anticoagulant. Journal of Biomedical Materials Research. Part A. ISSN 1549-3296. 101A(2), s. 575–581. doi: 10.1002/jbm.a.34348. Vis sammendrag

  Implantable devices are challenged with thrombus formation at their biomaterial interface. Thus the importance of identifying compatible biomaterials that will help to improve the performance of these devices are becoming increasingly paramount. The aim of this study was to evaluate the activation of coagulation and platelets by candidate membranes considered for use in implantable devices on the basis of an adapted whole blood model without soluble anticoagulants. Evaluated materials were incubated with whole blood without soluble anticoagulant in wells coated with heparin. Prothrombin fragment 1+2 (PTF 1+2), thrombin-antithrombin complex (TAT), and β-thromboglobulin (BTG) were analyzed in plasma samples using enzyme immunoassays. The C5 inhibitor eculizumab was used to evaluate the role of complement. Incubation of two of the polyamide membranes PAR and PATF led to an increase in concentration of PTF 1+2 and TAT (p < 0.01 for PAR, ns for PATF). The BTG concentration was significantly increased for five materials [PAR, PATF, polycarbonate (PC), and two polyarylethersulphone membranes PAES-1 and PAES-2]. Complement inhibition had no effect on coagulation or platelet activation induced by PAR and PATF. In conclusion, PAR and PATF were not compatible with blood and should be avoided for use in implantable devices.

• Holhjem, Lars; Strand-Amundsen, Runar; Aasmundtveit, Knut E. & Tønnessen, Tor Inge (2013). Development of a conductometric biocompatible sensor for detecting ischemia. I Poupon, Gilles (Red.), 19th European Microelectronics and Packaging Conference, EMPC 2013, Grenoble; France; 9 September 2013 through 12 September 2013. IEEE conference proceedings. ISSN 9782952746717. Vis sammendrag

  Insufficient blood supply to the organs is the major cause of morbidity and mortality worldwide. This condition must be detected early to avoid irreversible loss of function and tissue death as occurs with for instance myocardial infarction, stroke and many other diseases. It has been shown that CO2 tension in tissue is a valid variable for detecting insufficient blood supply in any organ, yet there exists no commercially available sensor capable of performing this measurement continuously, selectively and in real-time. In this paper we present a sensor prototype for measuring tissue tension of CO2 (PCO2) based on a conductometric principle. It has a diameter of 1mm, and is made purely of biocompatible materials. The sensor has been produced by injection moulding, laser patterning, electroplating and manual assembly. Its challenges of drift and long-time survivability are discussed. We will also discuss optimisation of electrode polarisation and stray capacitance of miniaturised electrodes, challenges that are relevant also for a larger span of miniaturised devices. We describe different in vivo experiments where the sensor has shown a lack of blood supply in several types of tissues with high sensitivity and specificity. It is expected that this approach will help to save the lives of patients and in the future become part of the standard of organ monitoring.

• Haugaa, Håkon; Almaas, Runar; Thorgersen, Ebbe Billmann; Foss, Aksel; Line, Pål Dag & Sanengen, Truls [Vis alle 13 forfattere av denne artikkelen] (2013). Clinical experience with microdialysis catheters in pediatric liver transplants. Liver transplantation. ISSN 1527-6465. 19(3), s. 305–314. doi: 10.1002/lt.23578.
• Haugaa, Håkon; Thorgersen, Ebbe Billmann; Pharo, Anne Margrethe; Boberg, Kirsten Muri; Foss, Aksel & Line, Pål Dag [Vis alle 13 forfattere av denne artikkelen] (2012). Inflammatory markers sampled by microdialysis catheters distinguish rejection from ischemia in liver grafts. Liver transplantation. ISSN 1527-6465. 18(12), s. 1421–1429. doi: 10.1002/lt.23503.
• Pischke, Søren Erik; Tronstad, Christian; Holhjem, Lars; Halvorsen, Per Steinar & Tønnessen, Tor Inge (2012). Perioperative detection of myocardial ischaemia/reperfusion with a novel tissue CO2 monitoring technology. European Journal of Cardio-Thoracic Surgery. ISSN 1010-7940. 42(1), s. 157–163. doi: 10.1093/ejcts/ezr278.
• Haugaa, Håkon; Thorgersen, Ebbe Billmann; Pharo, Anne Margrethe; Boberg, Kirsten Muri; Foss, Aksel & Line, Pål Dag [Vis alle 12 forfattere av denne artikkelen] (2012). Early bedside detection of ischemia and rejection in liver transplants by microdialysis. Liver transplantation. ISSN 1527-6465. 18(7), s. 839–849. doi: 10.1002/lt.23425.
• Wælgaard, Lars Torbjørn; Dahl, Berit Marie; Kvarstein, Gunnvald & Tønnessen, Tor Inge (2012). Tissue gas tensions and tissue metabolites for detection of organ hypoperfusion and ischemia. Acta Anaesthesiologica Scandinavica. ISSN 0001-5172. 56(2), s. 200–209. doi: 10.1111/j.1399-6576.2011.02572.x.
• Pischke, Søren Erik; Tronstad, Christian; Holhjem, Lars; Line, Pål Dag; Haugaa, Håkon & Tønnessen, Tor Inge (2012). Hepatic and Abdominal Carbon Dioxide Measurements Detect and Distinguish Hepatic Artery Occlusion and Portal Vein Occlusion in Pigs. Liver transplantation. ISSN 1527-6465. 18(12), s. 1485–1494. doi: 10.1002/lt.23544.
• Krushinitskaya, Olga Grigorievna; Tønnessen, Tor Inge; Jakobsen, Henrik & Johannessen, Erik (2011). The assessment of potentially interfering metabolites and dietary components in blood using an osmotic glucose sensor based on the concanavalin A-dextran affinity assay. Biosensors & Bioelectronics. ISSN 0956-5663. 28(1), s. 195–203. doi: 10.1016/j.bios.2011.07.019. Vis sammendrag

  Continuous surveillance of blood glucose is a prerogative of maintaining a tight glycaemic control in people suffering from diabetes mellitus. Implantable sensor technology offers the potential of conducting direct long term continuous glucose measurements, but current size restrictions and operational challenges have limited their applications. The osmotic sensor utilises diffusion to create a hydrostatic pressure that is independent of sensor operation and power consumption. This permits ultra-low power architectures to be realized with a minimal start-up time in a package suitable for miniaturization. In contrast, osmotic sensors suffer from the inability of their membranes to discriminate between different constituents in blood or the interstitial fluid that are of comparable size to glucose. By implementing an affinity assay based on the competitive bonding between concanavalin A and dextran, the selectivity of the membrane can be transferred to the glucose specific recognition of the affinity assay. The osmotic effect from the physiological levels of several key metabolites and nutritional components has been addressed identifying in particular ethanol, lactate and amino acids as potential interfering constituents. Both ascorbic acid and mannose would have a normal physiological concentration that is too low to be detected. The studies shows that an osmotic glucose sensor equipped with the con A–dextran affinity assay, is able to filter out potential interfering constituents present in blood, plasma and the interstitial fluid yet retaining a pressure that is proportional to glucose only.

• Barratt-Due, Andreas; Johansen, Harald Thidemann; Sokolov, Andrey; Thorgersen, Ebbe Billmann; Hellerud, Bernt C & Reubsaet, Leon [Vis alle 13 forfattere av denne artikkelen] (2011). The Role of Bradykinin and the Effect of the Bradykinin Receptor Antagonist Icatibant in Porcine Sepsis. Shock. ISSN 1073-2322. 36(5), s. 517–523. doi: 10.1097/SHK.0b013e3182336a34.
• Krushinitskaya, Olga Grigorievna; Tønnessen, Tor Inge; Jakobsen, Henrik & Johannessen, Erik A. (2011). Characterization of nanoporous membranes for implementation in an osmotic glucose sensor based on the concanavalin A–dextran affinity assay. Journal of Membrane Science. ISSN 0376-7388. 376(1-2), s. 153–161. doi: 10.1016/j.memsci.2011.04.009. Vis sammendrag

  Nanoporous membranes offering selectivity at the molecular level with a MWCO from 0 to 500 kDa were investigated with respect to permeability of key molecular constituents of an osmotic glucose sensor. The membrane should facilitate the passage of glucose (180 Da) with minimal delay, yet retain the larger molecular components of the concanavalin A–dextran affinity assay (60–102 kDa), using albumin (66 kDa) as a model. The results show that the membrane architecture plays just as an important factor as the pore size when it comes to determining the most functional membrane for the application. Further the viscous matrix of the affinity assay prevented the efflux of assay components that was observed using individual molecules such as albumin. It was found that the ceramic membrane from anodic aluminium oxide (AAO) with 4–6 nm pores within a membrane thickness of 1 μm constituted the best compromise with respect to glucose permeability, retention of assay components and response time.

• Johannessen, Erik; Krushinitskaya, Olga; Sokolov, Andrey; Häfliger, Philipp; Hoogerwerf, Arno & Hinderling, Christian [Vis alle 15 forfattere av denne artikkelen] (2010). Toward an injectable continuous osmotic glucose sensor. Journal of Diabetes Science and Technology. ISSN 1932-2968. 4(4), s. 882–892. Vis sammendrag

  BACKGROUND: The growing pandemic of diabetes mellitus places a stringent social and economic burden on the society. A tight glycemic control circumvents the detrimental effects, but the prerogative is the development of new more effective tools capable of longterm tracking of blood glucose (BG) in vivo. Such discontinuous sensor technologies will benefit from an unprecedented marked potential as well as reducing the current life expectancy gap of eight years as part of a therapeutic regime. METHOD: A sensor technology based on osmotic pressure incorporates a reversible competitive affinity assay performing glucose-specific recognition. An absolute change in particles generates a pressure that is proportional to the glucose concentration. An integrated pressure transducer and components developed from the silicon micro- and nanofabrication industry translate this pressure into BG data. RESULTS: An in vitro model based on a 3.6 x 8.7 mm large pill-shaped implant is equipped with a nanoporous membrane holding 4-6 nm large pores. The affinity assay offers a dynamic range of 36-720 mg/dl with a resolution of +/-16 mg/dl. An integrated 1 x 1 mm(2) large control chip samples the sensor signals for data processing and transmission back to the reader at a total power consumption of 76 microW. CONCLUSIONS: Current studies have demonstrated the design, layout, and performance of a prototype osmotic sensor in vitro using an affinity assay solution for up to four weeks. The small physical size conforms to an injectable device, forming the basis of a conceptual monitor that offers a tight glycemic control of BG. 2010 Diabetes Technology Society.

• Tronstad, Christian; Pischke, Søren Erik; Holhjem, L; Tønnessen, Tor Inge; Martinsen, Ørjan Grøttem & Grimnes, Sverre (2010). Early detection of cardiac ischemia using a conductometric pCO(2) sensor: real-time drift correction and parameterization. Physiological Measurement. ISSN 0967-3334. 31(9), s. 1241–1255. doi: 10.1088/0967-3334/31/9/013.
• Hellerud, Bernt C; Nielsen, Erik Waage; Thorgersen, Ebbe Billmann; Lindstad, Julie Katrine; Pharo, Anne Margrethe & Tønnessen, Tor Inge [Vis alle 9 forfattere av denne artikkelen] (2010). Dissecting the effects of lipopolysaccharides from nonlipopolysaccharide molecules in experimental porcine meningococcal sepsis. Critical Care Medicine. ISSN 0090-3493. 38(6), s. 1467–1474. doi: 10.1097/CCM.0b013e3181de8c94.
• Thorgersen, Ebbe Billmann; Hellerud, Bernt C; Nielsen, Erik Waage; Barratt-Due, Andreas; Fure, Hilde & Lindstad, Julie Katrine [Vis alle 12 forfattere av denne artikkelen] (2010). CD14 inhibition efficiently attenuates early inflammatory and hemostatic responses in Escherichia coli sepsis in pigs. The FASEB Journal. ISSN 0892-6638. 24(3), s. 712–722. doi: 10.1096/fj.09-140798.
• Krushinitskaya, Olga; Häfliger, Philipp; Vinsand, Tormod; Tønnessen, Tor Inge; Jakobsen, Henrik & Johannessen, Erik A. (2009). Novel Osmotic Sensor for a Continuous Implantable Blood-Sugar Reader. I NN, . (Red.), 6th International Workshop on Wearable Micro and Nano Technologies for Personalized Health (pHealth). IEEE conference proceedings. ISSN 978-1-4244-5252-1. s. 25–28. Vis sammendrag

  This paper presents the design and development of a novel osmotic glucose sensor that will be miniaturized to record the concentration of blood sugar in people suffering from diabetes mellitus. Key sensor components based on microfabrication technologies include a 1.03 bar differential silicon pressure transducer, nanoporous membrane and a 2 μW electronic interface combined with a wireless inductive powered communication link running at 13.56 MHz. The verification of the components and design principle in situ has permitted the detection of osmotic pressures from 0 to 40 mM glucose based on the direct measurements of glucose and the implementation of a reversible competitive affinity assay. The sensor components will be translated into a miniaturized package suitable for subcutaneous implantation.

• Kvarstein, Gunnvald; Måwe, Leif; Indahl, A; Hol, Per Kristian; Tennøe, Bjørn & Digernes, R [Vis alle 9 forfattere av denne artikkelen] (2009). A randomized double-blind controlled trial of intra-annular radiofrequency thermal disc therapy - A 12-month follow-up. Pain. ISSN 0304-3959. 145(3), s. 279–286. doi: 10.1016/j.pain.2009.05.001.
• Nielsen, Erik Waage; Hellerud, BC; Thorgersen, Ebbe B; Castellheim, A; Pharo, A & Lindstad, Julie [Vis alle 10 forfattere av denne artikkelen] (2009). A NEW DYNAMIC PORCINE MODEL OF MENINGOCOCCAL SHOCK. Shock. ISSN 1073-2322. 32(3), s. 302–309. doi: 10.1097/SHK.0b013e31819c37be.
• Castellheim, A; Thorgersen, EB; Hellerud, BC; Pharo, A; Johansen, HT & Brosstad, F [Vis alle 13 forfattere av denne artikkelen] (2008). New biomarkers in an acute model of live Escherichia coli-induced sepsis in pigs. Scandinavian Journal of Immunology. ISSN 0300-9475. 68, s. 75–84. doi: 10.1111/j.1365-3083.2008.02122.x.
• Wælgaard, Lars Torbjørn; Thorgersen, Ebbe Billmann; Line, Pål Dag; Foss, Aksel; Mollnes, Tom Eirik & Tønnessen, Tor Inge (2008). Microdialysis Monitoring of Liver Grafts by Metabolic Parameters, Cytokine Production, and Complement Activation. Transplantation. ISSN 0041-1337. 86(8), s. 1096–1103. doi: 10.1097/TP.0b013e31818775ca.
• Andersen, MH; Andersen, MH; Mathisen, L; Veenstra, M; Oyen, O & Edwin, B [Vis alle 14 forfattere av denne artikkelen] (2007). Quality of life after randomization to laparoscopic versus open living donor nephrectomy: Long-term follow-up. Transplantation. ISSN 0041-1337. 84(1), s. 64–69. doi: 10.1097/01.tp.0000268071.63977.42.
• Halvorsen, PS; Sokolovl, A; Cvancarova, M; Hol, PK; Lundblad, R & Tønnessen, Tor Inge (2007). Continuous cardiac output during off-pump coronary artery bypass surgery: pulse-contour analyses vs pulmonary artery thermodilution. British Journal of Anaesthesia. ISSN 0007-0912. 99, s. 484–492. doi: 10.1093/bja/aem199.
• Wælgaard, Lars; Pharo, Anne Margrethe; Tønnessen, Tor Inge & Mollnes, Tom Eirik (2006). Microdialysis for monitoring inflammation: Efficient recovery of cytokines and anaphylotoxins provided optimal catheter pore size and fluid velocity conditions. Scandinavian Journal of Immunology. ISSN 0300-9475. 64, s. 345–352.
• Halvorsen, PS; Espinoza, A; Lundblad, R; Cvancarova, M; Hol, PK & Fosse, Erik [Vis alle 7 forfattere av denne artikkelen] (2006). Agreement between PiCCO pulse-contour analysis, pulmonal artery thermodilution and transthoracic thermodilution during off-pump coronary artery by-pass surgery. Acta Anaesthesiologica Scandinavica. ISSN 0001-5172. 50, s. 1050–1057.
• Lingaas, Per Snorre; Hol, Per Kristian; Lundblad, Runar; Rein, Kjell Arne; Mathisen, Lars & Smith, Hans-Jørgen [Vis alle 14 forfattere av denne artikkelen] (2006). Clinical and Radiological Outcome of Off-Pump Coronary Surgery at 12 Months Follow-Up: A Prospective Randomized Trial. Annals of Thoracic Surgery. ISSN 0003-4975. 81(6), s. 289–295. doi: 10.1016/j.athoracsur.2005.12.003.
• Lingaas, Per Snorre; Hol, Per Kristian; Lundblad, Runar; Rein, Kjell Arne; Mathisen, Lars & Smith, Hans Jørgen [Vis alle 14 forfattere av denne artikkelen] (2006). Clinical and radiologic outcome of off-pump coronary surgery at 12 months follow-up: prospective randomized trial. . Annals of Thoracic Surgery. ISSN 0003-4975.
• Lingaas, Per Snorre; Hol, Per Kristian; Lundblad, Runar; Rein, Kjell Arne; Mathisen, Lars & Smith, Hans Jørgen [Vis alle 14 forfattere av denne artikkelen] (2006). Clinical and radiologic outcome of off-pump coronary surgery at 12 months follow-up: prospective randomized trial. . Annals of Thoracic Surgery. ISSN 0003-4975.
• Andersen, Marit Helen; Mathisen, Lars; Øyen, Ole; Edwin, Bjørn; Kvarstein, Gunnvald & Tønnessen, Tor Inge [Vis alle 9 forfattere av denne artikkelen] (2006). Postoperative pain and convalescence in living donors – laparoscopic versus open nephrectomy . American Journal of Transplantation. ISSN 1600-6135.
• Mathisen, Lars; Andersen, MH; Hol, PK; Lingaas, PS; Lundblad, R & Tønnessen, Tor Inge [Vis alle 14 forfattere av denne artikkelen] (2005). Patient-reported outcome after randomization to on-pump versus off-pump coronary artery surgery. Annals of Thoracic Surgery. ISSN 0003-4975. 79(5), s. 1584–1589. Vis sammendrag

  doi:10.1016/j.athoracsur.2004.10.019

• Kvarstein, Gunnvald; Mirtaheri, Peyman & Tønnessen, Tor Inge (2004). Detection of ischemia by PCO2 before adenosine triphosphate declines in skeletal muscle. Critical Care Medicine. ISSN 0090-3493. 32(1), s. 232–237.
• Mirtaheri, Peyman; Grimnes, Sverre; Martinsen, Ørjan Grøttem & Tønnessen, Tor Inge (2004). A new biomedical sensor for measuring PCO2. Physiological Measurement. ISSN 0967-3334. 25, s. 421–436.

Se alle arbeider i Cristin

• Laake, Jon Henrik; Aslam, Tayyba Naz; Barratt-Due, Andreas; Löwhagen, Bjørn; Pischke, Soeren & Tønnessen, Tor Inge [Vis alle 8 forfattere av denne artikkelen] (2023). ARDS eller akutt lungesviktsyndrom? Tidsskrift for Den norske legeforening. ISSN 0029-2001. 143(10). doi: 10.4045/tidsskr.23.0402.
• Laake, Jon Henrik; Astvad, Mads; Bentsen, Gunnar; Escher, Cecilia; Haney, Michael & Hoffmann-Petersen, Joachim [Vis alle 19 forfattere av denne artikkelen] (2022). A policy for diversity, equity, inclusion and anti-racism in the Scandinavian Society of Anaesthesiology and Intensive Care Medicine (SSAI). Acta Anaesthesiologica Scandinavica. ISSN 0001-5172. 66(1), s. 141–144. doi: 10.1111/aas.13978.
• Haugaa, Håkon; Line, Pål Dag & Tønnessen, Tor Inge (2020). An Increased Lactate-to-pyruvate Ratio Is Not a Stand-alone Marker of Ischemia. Transplantation direct. ISSN 2373-8731. doi: 10.1097/TXD.0000000000000991.
• Lindholm, Espen & Tønnessen, Tor Inge (2020). Langvarig syk etter covid-19. Tidsskrift for Den norske legeforening. ISSN 0029-2001.
• Hausken, John; Fretland, Åsmund A.; Edwin, Bjørn; Kvarstein, Gunnvald & Tønnessen, Tor Inge (2019). Response to the Comment on "Epidural Analgesia (TEA) vs. IV-PCA After Open Liver Surgery". Annals of Surgery. ISSN 0003-4932. 271(5). doi: 10.1097/SLA.0000000000003684.
• Laake, Jon Henrik; Tønnessen, Tor Inge; Chew, M.S.; Lipcsey, M.; Hjelmqvist, H. & Wilkman, E. [Vis alle 9 forfattere av denne artikkelen] (2018). The SSAI fully supports the suspension of hydroxyethyl-starch solutions commissioned by the European Medicines Agency. Acta Anaesthesiologica Scandinavica. ISSN 0001-5172. 62(6), s. 874–875. doi: 10.1111/aas.13120.
• Stafseth, Siv Anna Ulla-Britt Karlsson; Tønnessen, Tor Inge & Fagerström, Lisbeth (2018). Test of reliability and Validity of NAS in critical care nursing.
• Tønnessen, Tor Inge (2016). Re: Skal feber hos intensivpasienter behandles? Tidsskrift for Den norske legeforening. ISSN 0029-2001. 136(5), s. 380–381. doi: 10.4045/tidsskr.16.0171.
• Strand-Amundsen, Runar James; Tronstad, Christian; Martinsen, Ørjan Grøttem; Høgetveit, Jan Olav; Ruud, TE & Tønnessen, Tor Inge (2016). Bioimpedance - in vivo vs in vitro ischemic small intestine. Proceedings of the 16th International Conference on Electrical Bioimpedance.
• Haugaa, Håkon & Tønnessen, Tor Inge (2011). Bedside Detection of Rejection and Ischemia in Pediatric Liver Transplants. Liver transplantation. ISSN 1527-6465. 17(6), s. S127–S127.
• Haugaa, Håkon & Tønnessen, Tor Inge (2011). LIVER TRANSPLANTATION: BEDSIDE DETECTION OF REJECTION AND ISCHEMIA BY MICRODIALYSIS CATHETERS. Pediatric Transplantation. ISSN 1397-3142. 15, s. 58–59.
• Krushinitskaya, Olga Grigorievna; Tønnessen, Tor Inge; Jakobsen, Henrik & Johannessen, Erik (2010). Membrane dynamics of an implantable osmotic glucose sensor.
• Thorgersen, Ebbe Billmann; Hellerud, Bernt C; Nielsen, Erik Waage; Barratt-Due, Andreas; Fure, Hilde & Lindstad, Julie Katrine [Vis alle 12 forfattere av denne artikkelen] (2010). Upstream inhibition of key innate immune pathways in vivo in sepsis. Molecular Immunology. ISSN 0161-5890. 47(13), s. 2268–2268. doi: 10.1016/j.molimm.2010.05.209.
• Kvarstein, Gunnvald; Måwe, Leif; Indahl, A; Hol, Per Kristian; Tennøe, Bjørn & Digernes, R [Vis alle 9 forfattere av denne artikkelen] (2010). Placebo control - Still the most ethical study design. Pain. ISSN 0304-3959. 148(1), s. 174–175. doi: 10.1016/j.pain.2009.11.013.
• Haugaa, Håkon & Tønnessen, Tor Inge (2010). Monitoring Metabolic Parameters in Liver Transplants with Microdialysis Detects Vascular Disturbances and Rejection. Liver transplantation. ISSN 1527-6465. 16(6), s. S72–S72.
• Haugaa, Håkon; Thorgersen, Ebbe Billmann; Foss, Aksel; Pharo, Anne Margrethe; Mollnes, Tom Eirik & Tønnessen, Tor Inge (2010). Microdialysis Catheters in Liver Transplants Detect Rejection Prior to Biopsy. Liver transplantation. ISSN 1527-6465. 16(6), s. S84–S85.
• Haugaa, Håkon; Hausken, John; Jørgensen, Pål Foyn; Scholz, Tim & Tønnessen, Tor Inge (2010). MONITORING INTRAHEPATIC METABOLISM BY MICRODIALYSIS IN LIVER GRAFTS DETECTS ISCHEMIA AND ACUTE REJECTION. Hepatology. ISSN 0270-9139. 52(4), s. 861A–862A.
• Haugaa, Håkon; Hausken, John; Jørgensen, Pål Foyn; Scholz, Tim & Tønnessen, Tor Inge (2010). MICRODIALYSIS REVEALS A HYPER METABOLIC CONDITION CAUSED BY INFLAMMATORY CELLS DURING REJECTION OF LIVER TRANSPLANTS. Hepatology. ISSN 0270-9139. 52(4), s. 846A–846A.
• Krushinitskaya, Olga; Tenstad, Ellen; Vinsand, Tormod; Tønnessen, Tor Inge; Jakobsen, Henrik & Johannessen, Erik (2009). Osmotic glucose sensor for continuous measurements in vivo, Proceedings of MicroTAS 2009, The 13th International Conference on Miniaturized Systems for Chemistry and Life Sciences, Jeju, South Korea, 1–5 November 2009. The Chemical and Biological Microsystems Society. ISSN 978-0-9798064-2-1. s. 1654–1655.
• Krushinitskaya, Olga; Tønnessen, Tor Inge; Jakobsen, Henrik & Johannessen, Erik (2009). Osmotic Sensor for Biomedical Research, Proceedings of IMAPS Nordic 2009. IMAPS Nordic. ISSN 9789529975167. s. 13–16. Vis sammendrag

  This paper presents initial results in the investigation of the correlation between reduced pitches and reliability of interconnects using anisotropic conductive film (ACF). ACF interconnects were characterized with focus on curing temperature of adhesives and bond pressure. Bonded samples were evaluated by four-point electrical resistance measurement. Samples for further investigation were fabricated with selected parameters from initial characterization. Insulation resistance between ACF interconnects were then measured to determine the short circuit rate of samples with different pitches. The ACF used in this study was a 20 µm thick single layer ACF filled with 5 µm diameter conductive particles. Silicon based test chips and substrates, with interconnect pitch ranging from 110 µm to 200 µm have been designed to study the effect of pitch on reliability of the ACF interconnects. Characterization results showed that sufficient interconnect resistance could be obtained with bond pressure ranging from 100 to 140 MPa, while bond temperature was 180 oC. Insulation resistance between ACF joints in two separate daisy chains was sufficiently high (approximately 1 GO) and independent of pitch factor. This initial study has verified the feasibility of reduced pitch down to 110 µm for ACF interconnects. Based on this study, further investigations into effect of rough environments on ACF joints with different pitches will be of interest.

• Hellerud, Bernt C; Thorgersen, Ebbe Billmann; Castellheim, Albert; Nielsen, EW; Pharo, Anne Margrethe & Lindstad, Julie Katrine [Vis alle 10 forfattere av denne artikkelen] (2007). The role of complement and CD14 in the Gram-negative bacteria induced inflammatory reaction: In vitro evidence and design of an in vivo porcine model. Molecular Immunology. ISSN 0161-5890. 44, s. 182–182. doi: 10.1016/j.molimm.2006.07.085.

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