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- Skytte Larsson, Jenny, et al.
(author)
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Renal Blood Flow, Glomerular Filtration Rate, and Renal Oxygenation in Early Clinical Septic Shock
- 2018
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In: Critical Care Medicine. - : Ovid Technologies (Wolters Kluwer Health). - 0090-3493. ; 46:6
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Journal article (peer-reviewed)abstract
- Objective: Data on renal hemodynamics, function, and oxygenation in early clinical septic shock are lacking. We therefore measured renal blood flow, glomerular filtration rate, renal oxygen consumption, and oxygenation in patients with early septic shock. Patients: Patients with norepinephrine-dependent early septic shock (n = 8) were studied within 24 hours after arrival in the ICU and compared with postcardiac surgery patients without acute kidney injury (comparator group, n = 58). Measurements and Main Results: Data on systemic hemodynamics and renal variables were obtained during two 30-minute periods. Renal blood flow was measured by the infusion clearance of para-aminohippuric acid, corrected for renal extraction of para-aminohippuric acid. Renal filtration fraction was measured by renal extraction of chromium-51 labeled EDTA. Renal oxygenation was estimated from renal oxygen extraction. Renal oxygen delivery (-24%; p = 0.037) and the renal blood flow-to-cardiac index ratio (-21%; p = 0.018) were lower, renal vascular resistance was higher (26%; p = 0.027), whereas renal blood flow tended to be lower (-19%; p = 0.068) in the septic group. Glomerular filtration rate (-32%; p = 0.006) and renal sodium reabsorption (-29%; p = 0.014) were both lower in the septic group. Neither renal filtration fraction nor renal oxygen consumption differed significantly between groups. Renal oxygen extraction was significantly higher in the septic group (28%; p = 0.022). In the septic group, markers of tubular injury were elevated. Conclusions: In early clinical septic shock, renal function was lower, which was accompanied by renal vasoconstriction, a lower renal oxygen delivery, impaired renal oxygenation, and tubular sodium reabsorption at a high oxygen cost compared with controls.
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| 2. |
- Skytte Larsson, Jenny, et al.
(author)
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Renal effects of norepinephrine-induced variations in mean arterial pressure after liver transplantation: A randomized cross-over trial
- 2018
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In: Acta Anaesthesiologica Scandinavica. - : Wiley. - 0001-5172. ; 62:9, s. 1229-1236
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Journal article (peer-reviewed)abstract
- BackgroundAcute kidney injury is commonly seen after liver transplantation. The optimal perioperative target mean arterial pressure (MAP) for renal filtration, perfusion and oxygenation in liver recipients is not known. The effects of norepinephrine-induced changes in MAP on renal blood flow (RBF), oxygen delivery (RDO2), glomerular filtration rate (GFR) and renal oxygenation (=renal oxygen extraction, RO(2)Ex) were therefore studied early after liver transplantation. MethodsTen patients with an intra- and post-operative vasopressor-dependent systemic vasodilation were studied early after liver transplantation during sedation and mechanical ventilation. To achieve target MAP levels of 60, 75 and 90mmHg, the norepinephrine infusion rate was randomly and sequentially titrated. At each target MAP, data on cardiac index (CI), RBF and GFR were obtained by transpulmonary thermodilution (PiCCO), the renal vein thermodilution technique and renal extraction of chromium ethylenediaminetetraaceticacid (Cr-51-EDTA), respectively. Renal oxygen consumption (RVO2) and extraction (RO(2)Ex) were calculated according to standard formulas. ResultsAt a target MAP of 75mmHg, CI (13%), RBF (18%), RDO2 (24%), GFR (31%) and RVO2 (20%) were higher while RO(2)Ex was unchanged compared to a target MAP of 60mmHg. Increasing MAP from 75 up to 90mmHg increased RVR by 38% but had no further effects on CI, RBF, RDO2 or GFR. ConclusionsIn patients undergoing liver transplantation, RBF and GFR are pressure-dependent at MAP levels below 75mmHg. Our results suggest that MAP should probably be targeted to approximately 75mmHg for optimal perioperative renal filtration, perfusion and oxygenation in patients undergoing liver transplantation.
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| 3. |
- Skytte Larsson, Jenny, et al.
(author)
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Renal function and oxygenation are impaired early after liver transplantation despite hyperdynamic systemic circulation.
- 2017
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In: Critical Care. - : Springer Science and Business Media LLC. - 1364-8535 .- 1466-609X. ; 21:1
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Journal article (peer-reviewed)abstract
- Acute kidney injury (AKI) occurs frequently after liver transplantation and is associated with the development of chronic kidney disease and increased mortality. There is a lack of data on renal blood flow (RBF), oxygen consumption, glomerular filtration rate (GFR) and renal oxygenation, i.e. the renal oxygen supply/demand relationship, early after liver transplantation. Increased insight into the renal pathophysiology after liver transplantation is needed to improve the prevention and treatment of postoperative AKI. We have therefore studied renal hemodynamics, function and oxygenation early after liver transplantation in humans.Systemic hemodynamic and renal variables were measured during two 30-min periods in liver transplant recipients (n=12) and post-cardiac surgery patients (controls, n=73). RBF and GFR were measured by the renal vein retrograde thermodilution technique and by renal extraction of Cr-EDTA (= filtration fraction), respectively. Renal oxygenation was estimated from the renal oxygen extraction.In the liver transplant group, GFR decreased by 40% (p<0.05), compared to the preoperative value. Cardiac index and systemic vascular resistance index were 65% higher (p<0.001) and 36% lower (p<0.001), respectively, in the liver transplant recipients compared to the control group. GFR was 27% (p<0.05) and filtration fraction 40% (p<0.01) lower in the liver transplant group. Renal vascular resistance was 15% lower (p<0.05) and RBF was 18% higher (p<0.05) in liver transplant recipients, but the ratio between RBF and cardiac index was 27% lower (p<0.001) among the liver-transplanted patients compared to the control group. Renal oxygen consumption and extraction were both higher in the liver transplants, 44% (p<0.01) and 24% (p<0.05) respectively.Despite the hyperdynamic systemic circulation and renal vasodilation, there is a severe decline in renal function directly after liver transplantation. This decline is accompanied by an impaired renal oxygenation, as the pronounced elevation of renal oxygen consumption is not met by a proportional increase in renal oxygen delivery. This information may provide new insights into renal pathophysiology as a basis for future strategies to prevent/treat AKI after liver transplantation.ClinicalTrials.gov, NCT02455115 . Registered on 23 April 2015.
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| 4. |
- Sondergaard, S, et al.
(author)
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The haemodynamic effects of crystalloid and colloid volume resuscitation on primary, derived and efficiency variables in post-CABG patients.
- 2019
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In: Intensive care medicine experimental. - : Springer Science and Business Media LLC. - 2197-425X. ; 7:1
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Journal article (peer-reviewed)abstract
- Recent studies in haemodynamic management have focused on fluid management and assessed its effects in terms of increase in cardiac output based on fluid challenges or variations in pulse pressure caused by cyclical positive pressure ventilation. The theoretical scope may be characterised as Starling-oriented. This approach ignores the actual events of right-sided excitation and left-sided response which is consistently described in a Guyton-oriented model of the cardiovascular system.Based on data from a previous study, we aim to elucidate the primary response to crystalloid and colloid fluids in terms of cardiac output, mean blood pressure and right atrial pressure as well as derived and efficiency variables defined in terms of Guyton venous return physiology.Re-analyses of previously published data.Cardiac output invariably increased on infusion of crystalloid and colloid solutions, whereas static and dynamic efficiency measures declined in spite of increasing pressure gradient for venous return.We argue that primary as well as derived and efficiency measures should be reported and discussed when haemodynamic studies are reported involving fluid administrations.
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