| 1. |
- Bragadottir, Gudrun, et al.
(författare)
-
Assessing glomerular filtration rate (GFR) in critically ill patients with acute kidney injury - true GFR versus urinary creatinine clearance and estimating equations.
- 2013
-
Ingår i: Critical care (London, England). - : Springer Science and Business Media LLC. - 1466-609X .- 1364-8535. ; 17:3
-
Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Estimation of kidney function in critically ill patients with acute kidney injury (AKI), is important for appropriate dosing of drugs and adjustment of therapeutic strategies, but challenging due to fluctuations in kidney function, creatinine metabolism and fluid balance. Data on the agreement between estimating and gold standard methods to assess glomerular filtration rate (GFR) in early AKI are lacking. We evaluated the agreement of urinary creatinine clearance (CrCl) and three commonly used estimating equations, the Cockcroft Gault (CG), the Modification of Diet in Renal Disease (MDRD) and the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations, in comparison to GFR measured by the infusion clearance of 51Cr-EDTA, in critically ill patients with early AKI after complicated cardiac surgery. METHODS: Thirty patients with early AKI were studied in the intensive care unit, 2 to 12 days after complicated cardiac surgery. Infusion clearance for Chromium-ethylenediaminetetraacetic acid (51Cr-EDTA) was obtained as a measure of GFR (GFR51Cr-EDTA) calculated from the formula; GFR (mL/min/1.73m2) = (51Cr-EDTA infusion rate x 1.73) / (arterial 51Cr-EDTA x BSA) and compared with the urinary CrCl and the estimated GFR (eGFR) from the three estimating equations. Urine was collected in two 30 min periods to measure urine flow and urine creatinine. Urinary CrCl was calculated from the formula; CrCl (mL/min/1.73m2) = (urine volume x urine creatinine x 1.73) / (serum creatinine x 30min x BSA). RESULTS: The within-group error was lower for GFR51Cr-EDTA than the urinary CrCl method, 7.2 %. vs. 55.0 %. The between-method bias was 2.6, 11.6, 11.1 and 7.39 ml/min, for eGFRCrCl, eGFRMDRD , eGFRCKD-EPI and eGFRCG , respectively, when compared to GFR51Cr-EDTA. The error was 103, 68.7, 67.7 and 68.0 % for eGFRCrCl, eGFRMDRD, eGFRCKD-EPI and eGFRCG, respectively when compared to GFR51Cr-EDTA. CONCLUSIONS: The study demonstrated a poor precision of the commonly utilized urinary CrCl method for assessment of GFR in critically ill patients with early AKI and should not be used as a reference method when validating new methods for assessing kidney function in this patient population. The commonly used estimating equations perform poorly, when estimating GFR, with high biases and unacceptably high errors.
|
|
| 2. |
- Bragadottir, Gudrun
(författare)
-
Cardiac surgery and the kidney - studies on the effects of pharmacological interventions on renal perfusion, filtration and oxygenation
- 2013
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Acute kidney injury (AKI) commonly complicates cardiac surgery and is associated with high mortality. Renal ischemia is considered to be the major cause. There is a close association between glomerular filtration rate (GFR), tubular sodium reabsorption and renal oxygen consumption (RVO2) in humans. The filtered load of sodium is an important determinant of RVO2 and any agent that increases GFR has the potential to increase RVO2. An ideal agent to treat patients with AKI would be one that increases both renal blood flow (RBF) and GFR, with no impairment in renal oxygenation, defined as the renal oxygen supply/demand relationship, the inverse of this relationship being the renal extraction of O2 (RO2Ex). Data on the effects of pharmacological interventions on RBF, GFR and renal oxygenation, are scarce. Patients and methods: The renal vein thermodilution technique was used to analyse the effects of vasopressin (n=12) and the effects of levosimendan vs placebo (n=30), on RBF, GFR and renal oxygenation in post-cardiac surgery patients. The effects of mannitol on RBF, GFR and renal oxygenation were studied in patients (n=11) with AKI after cardiac surgery. The agreement of urinary creatinine clearance (CrCl) and three commonly used estimating equations, in comparison to GFR, measured by the infusion clearance of 51Cr-EDTA, were evaluated in critically ill patients with AKI. Results: Vasopressin increased renal vascular resistance (RVR) and decreased RBF, while GFR, RVO2 and RO2Ex increased. Mannitol in AKI, increased urine flow, decreased RVR and increased RBF. Mannitol tended to increase GFR and RVO2 but did not change RO2Ex. Compared to placebo, levosimendan decreased RVR and increased RBF and GFR, while RVO2 and RO2Ex were not affected. Finally, the within-group error was higher for the urinary CrCl method than the 51Cr-EDTA clearance method. The urinary CrCl method and the estimating equations had high biases and high errors compared to GFR measured by 51Cr-EDTA. Conclusion: The vasopressin-induced increase in GFR was caused by post-glomerular renal vasoconstriction, accompanied by an increase in RVO2 and RO2Ex. Thus, vasopressin impaired renal oxygenation. Mannitol treatment of AKI induced a renal vasodilation and increased RBF. Mannitol did neither affect filtration fraction nor renal oxygenation, suggestive of balanced increases in perfusion/filtration and oxygen demand/supply. Levosimendan induced a vasodilation, preferentially of pre-glomerular resistance vessels, increasing both RBF and GFR without jeopardizing renal oxygenation. Levosimendan could therefore be a potentially useful agent for treatment of AKI in patients with heart failure. Assessment of GFR by the urinary CrCl method, had a poor precision in critically ill patients with AKI, and should not be used as a reference method, when validating new methods for assessing kidney function in this patient population. All the estimating equations performed poorly, when estimating GFR in these patients.
|
|
| 3. |
- Bragadottir, Gudrun, et al.
(författare)
-
Effects of Levosimendan on Glomerular Filtration Rate, Renal Blood Flow, and Renal Oxygenation After Cardiac Surgery With Cardiopulmonary Bypass: A Randomized Placebo-Controlled Study.
- 2013
-
Ingår i: Critical care medicine. - 1530-0293. ; 41:10, s. 2328-2335
-
Tidskriftsartikel (refereegranskat)abstract
- Acute kidney injury develops in a large proportion of patients after cardiac surgery because of the low cardiac output syndrome. The inodilator levosimendan increases cardiac output after cardiac surgery with cardiopulmonary bypass, but a detailed analysis of its effects on renal perfusion, glomerular filtration, and renal oxygenation in this group of patients is lacking. We therefore evaluated the effects of levosimendan on renal blood flow, glomerular filtration rate, renal oxygen consumption, and renal oxygen demand/supply relationship, i.e., renal oxygen extraction, early after cardiac surgery with cardiopulmonary bypass.
|
|
| 4. |
- Bragadottir, Gudrun, et al.
(författare)
-
Low-dose vasopressin increases glomerular filtration rate, but impairs renal oxygenation in post-cardiac surgery patients.
- 2009
-
Ingår i: Acta Anaesthesiol Scand. - : Wiley. - 1399-6576. ; 53:8, s. 1052-9
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The beneficial effects of vasopressin on diuresis and creatinine clearance have been demonstrated when used as an additional/alternative therapy in catecholamine-dependent vasodilatory shock. A detailed analysis of the effects of vasopressin on renal perfusion, glomerular filtration, excretory function and oxygenation in man is, however, lacking. The objective of this pharmacodynamic study was to evaluate the effects of low to moderate doses of vasopressin on renal blood flow (RBF), glomerular filtration rate (GFR), renal oxygen consumption (RVO2) and renal oxygen extraction (RO2Ex) in post-cardiac surgery patients. METHODS: Twelve patients were studied during sedation and mechanical ventilation after cardiac surgery. Vasopressin was sequentially infused at 1.2, 2.4 and 4.8 U/h. At each infusion rate, systemic haemodynamics were evaluated by a pulmonary artery catheter, and RBF and GFR were measured by the renal vein thermodilution technique and by renal extraction of 51chromium-ethylenediaminetetraacetic acid, respectively. RVO2 and RO2Ex were calculated by arterial and renal vein blood samples. RESULTS: The mean arterial pressure was not affected by vasopressin while cardiac output and heart rate decreased. RBF decreased and GFR, filtration fraction, sodium reabsorption, RVO2, RO2Ex and renal vascular resistance increased dose-dependently with vasopressin. Vasopressin exerted direct antidiuretic and antinatriuretic effects. CONCLUSIONS: Short-term infusion of low to moderate, non-hypertensive doses of vasopressin induced a post-glomerular renal vasoconstriction with a decrease in RBF and an increase in GFR in post-cardiac surgery patients. This was accompanied by an increase in RVO2, as a consequence of the increases in the filtered tubular load of sodium. Finally, vasopressin impaired the renal oxygen demand/supply relationship.
|
|
| 5. |
- Bragadottir, Gudrun, et al.
(författare)
-
Mannitol increases renal blood flow and maintains filtration fraction and oxygenation in postoperative acute kidney injury: a prospective interventional study.
- 2012
-
Ingår i: Critical Care. - : Springer Science and Business Media LLC. - 1364-8535 .- 1466-609X. ; 16:4
-
Tidskriftsartikel (refereegranskat)abstract
- ABSTRACT: INTRODUCTION: Acute kidney injury (AKI), which is a major complication after cardiovascular surgery, is associated with significant morbidity and mortality. Diuretic agents are frequently used to improve urine output, and to facilitate fluid management in these patients. Mannitol, an osmotic diuretic, is used in the perioperative setting in the belief that it exerts reno-protective properties. In a recent study on uncomplicated post-cardiac surgery patients with normal renal function, mannitol increased glomerular filtration rate (GFR), possibly by a de-swelling effect on tubular cells. Furthermore, experimental studies have previously shown that renal ischemia causes an endothelial cell injury and dysfunction followed by endothelial cell oedema. We studied the effects of mannitol on renal blood flow (RBF), glomerular filtration rate (GFR), renal oxygen consumption (RVO2) and extraction (RO2Ex) in early, ischaemic AKI after cardiac surgery. METHODS: Eleven patients with AKI were studied during propofol sedation and mechanical ventilation 2-6 days after complicated cardiac surgery. All patients had severe heart failure treated with one (100%) or two (73%) inotropic agents and intra-aortic balloon pump (36%). Systemic haemodynamics were measured by a pulmonary artery catheter. RBF and renal filtration fraction (FF) were measured by the renal vein thermo-dilution technique and by renal extraction of chromium-51- ethylenediaminetetraacetic acid (51Cr-EDTA), respectively. GFR was calculated as the product of FF and renal plasma flow RBF x (1-hematocrit). RVO2 and RO2Ex were calculated from arterial and renal vein blood samples according to standard formulae. After control measurements, a bolus dose of mannitol 225 mg/kg, was given followed by an infusion at a rate of 75 mg/kg/h for two 30-minute periods. RESULTS: Mannitol did not affect cardiac index or cardiac filling pressures. Mannitol increased urine flow by 61% (P<0.001). This was accompanied by a 12% increase in RBF (P<0.05) and 13% decrease in renal vascular resistance (P<0.05). Mannitol increased the RBF/cardiac output (CO) relationship (P=0.040). Mannitol caused no significant changes in RO2Ext or renal FF. CONCLUSIONS: Mannitol treatment of postoperative AKI induces a renal vasodilation and redistributes systemic blood flow to the kidneys. Mannitol does not affect filtration fraction or renal oxygenation, suggestive of balanced increases in perfusion/filtration and oxygen demand/supply.
|
|
| 6. |
- Corderfeldt, Anna, et al.
(författare)
-
Non-invasive and invasive measurement of skeletal muscular oxygenation during isolated limb perfusion
- 2023
-
Ingår i: Perfusion-Uk. - : SAGE Publications. - 0267-6591. ; 38:5, s. 1019-1028
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Isolated limb perfusion (ILP) is a regional surgical treatment for localized metastatic disease. High doses of chemotherapeutic agents are administered within an extracorporeal circulated isolated extremity, treating the metastasis, while systemic toxicity is avoided. To our knowledge, indexed oxygen supply/demand relationship during ILP has not previously been described. Our aim was to measure and describe oxygen metabolism, specifically oxygen delivery, consumption, and extraction, in an isolated leg/arm during ILP. Also investigate whether invasive oxygenation measurement during ILP correlates and can be used interchangeable with the non-invasive method, near infrared spectroscopy (NIRS). Methods: Data from 40 patients scheduled for ILP were included. At six time points blood samples were drawn during the procedure. DO2, VO2, and O2ER were calculated according to standard formulas. NIRS and hemodynamics were recorded every 10 min. Results: For all observations, the mean of DO2 was 190 +/- 59 ml/min/m(2), VO2 was 35 +/- 8 ml/min/m(2), and O2ER was 21 +/- 8%. VO2 was significantly higher in legs compared to arms (38 +/- 8 vs. 29 +/- 7 ml/min/m(2), p=0.02). Repeated measures showed a significant decrease in DO2 in legs (209 +/- 65 to 180 +/- 66 ml/min/m(2), p=<0.01) and in arms (252 +/- 72 to 150 +/- 57 ml/min/m(2), p=<0.01). Significant increase in O2ER in arms was also found (p=0.03). Significant correlation was detected between NIRS and venous extremity oxygen saturation (SveO(2)) (r(rm)=0.568, p=<. 001, 95% CI 0.397-0.701). When comparing SveO(2) and NIRS using a Bland-Altman analysis, the mean difference (bias) was 8.26 +/- 13.03 (p=<. 001) and the limit of agreement was - 17.28-33.09, with an error of 32.5%. Conclusion: DO2 above 170 ml/min/m(2) during ILP kept O2ER below 30% for all observations. NIRS correlates significant to SveO(2); however, the two methods do not agree sufficiently to work interchangeable.
|
|
| 7. |
- Lannemyr, Lukas, 1974, et al.
(författare)
-
Effects of Cardiopulmonary Bypass on Renal Perfusion, Filtration, and Oxygenation in Patients Undergoing Cardiac Surgery.
- 2017
-
Ingår i: Anesthesiology. - 1528-1175. ; 126:2, s. 205-213
-
Tidskriftsartikel (refereegranskat)abstract
- Acute kidney injury is a common complication after cardiac surgery with cardiopulmonary bypass. The authors evaluated the effects of normothermic cardiopulmonary bypass on renal blood flow, glomerular filtration rate, renal oxygen consumption, and renal oxygen supply/demand relationship, i.e., renal oxygenation (primary outcome) in patients undergoing cardiac surgery.Eighteen patients with a normal preoperative serum creatinine undergoing cardiac surgery procedures with normothermic cardiopulmonary bypass (2.5 l · min · m) were included after informed consent. Systemic and renal hemodynamic variables were measured by pulmonary artery and renal vein catheters before, during, and after cardiopulmonary bypass. Arterial and renal vein blood samples were taken for measurements of renal oxygen delivery and consumption. Renal oxygenation was estimated from the renal oxygen extraction. Urinary N-acetyl-β-D-glucosaminidase was measured before, during, and after cardiopulmonary bypass.Cardiopulmonary bypass induced a renal vasoconstriction and redistribution of blood flow away from the kidneys, which in combination with hemodilution decreased renal oxygen delivery by 20%, while glomerular filtration rate and renal oxygen consumption were unchanged. Thus, renal oxygen extraction increased by 39 to 45%, indicating a renal oxygen supply/demand mismatch during cardiopulmonary bypass. After weaning from cardiopulmonary bypass, renal oxygenation was further impaired due to hemodilution and an increase in renal oxygen consumption, accompanied by a seven-fold increase in the urinary N-acetyl-β-D-glucosaminidase/creatinine ratio.Cardiopulmonary bypass impairs renal oxygenation due to renal vasoconstriction and hemodilution during and after cardiopulmonary bypass, accompanied by increased release of a tubular injury marker.
|
|
| 8. |
- Lannemyr, Lukas, 1974, et al.
(författare)
-
Effects of milrinone on renal perfusion, filtration and oxygenation in patients with acute heart failure and low cardiac output early after cardiac surgery
- 2020
-
Ingår i: Journal of Critical Care. - : Elsevier BV. - 0883-9441. ; 57, s. 225-230
-
Tidskriftsartikel (refereegranskat)abstract
- Purpose: Early postoperative heart failure is common after cardiac surgery, and inotrope treatment may impact renal perfusion and oxygenation. We aimed to study the renal effects of the inodilator milrinone when used for the treatment of heart failure after weaning from cardiopulmonary bypass (CPB). Material and methods: In 26 patients undergoing cardiac surgery with CPB, we used renal vein catheterization to prospectively measure renal blood flow (RBF), glomerular filtration rate (GFR), and renal oxygenation. Patients who developed acute heart failure and lowcardiac output (cardiac index b2.1 L/min/m2) at 30min afterweaning fromCPB (n= 7) were given milrinone, and the remaining patients (n= 19) served as controls. Additionalmeasurements were made at 60 min after CPB. Results: In patientswith acute postoperative heart failure, before receiving milrinone, renal blood flow was lower (-33%, p b.05) while renal oxygen extraction was higher (41%, p b.05) compared to the control group. Milrinone increased cardiac index (21%, p b.001), RBF (36%, p b.01) and renal oxygen delivery (35%, p b.01), with no significant change in GFR and oxygen consumption compared to the control group. Conclusions: In patients with acute heart failure after weaning from CPB, the milrinone-induced increase in cardiac output was accompanied by improved renal oxygenation. Trial registration: ClinicalTrials.gov; identifier NCT02405195, date of registration; March 27, 2015, and NCT02549066, date of registration; 9 September 2015. (c) 2020 Elsevier Inc. All rights reserved.
|
|
| 9. |
- Lannemyr, Lukas, 1974, et al.
(författare)
-
Impact of Cardiopulmonary Bypass Flow on Renal Oxygenation in Patients Undergoing Cardiac Operations
- 2019
-
Ingår i: The Annals of thoracic surgery. - : Elsevier BV. - 1552-6259 .- 0003-4975. ; 107:2, s. 505-511
-
Tidskriftsartikel (refereegranskat)abstract
- Cardiac surgery with cardiopulmonary bypass (CPB) is associated with acute kidney injury, and the risk increases with low oxygen delivery during CPB. We hypothesized that renal oxygenation could be improved at higher than normal CPB flow rates.After ethical approval and informed consent, 17 patients with normal serum creatinine undergoing normothermic CPB were included and received pulmonary artery and renal vein catheters after anesthesia induction for measurements of systemic and renal variables. Renal oxygen extraction (RO2Ex), a direct measure of the renal oxygen delivery /renal oxygen consumption ratio, and renal filtration fraction were measured, the latter by renal extraction of 51chromium-EDTA. After start of CPB and aortic cross-clamp, the pump flow rate was randomly varied between 2.4, 2.7 and 3.0 l·min-1·m-2 and measurements were made after 10 minutes at each flow rate.RO2Ex increased by 30% at a flow rate of 2.4 l·min-1·m-2 vs. pre-CPB (p<0.05). At a flow rate of 2.7 and 3.0 l·min-1·m-2, RO2Ex was 12% (p<0.05) and 23% (p<0.01) lower, respectively, compared to 2.4 l·min-1·m-2. This corresponds to a 14% and 30% improvement, respectively, of the renal oxygen supply/demand relationship. Filtration fraction was not affected by changes in flow rate, indicating that the glomerular filtration rate increased in proportion to the increase in renal perfusion.The impaired renal oxygenation seen during CPB is ameliorated by an increase in CPB flow rate. Thus, one way to protect the kidneys, during CPB, could be to use a higher flow rate than the one traditionally used.
|
|
| 10. |
- Lannemyr, Lukas, 1974, et al.
(författare)
-
Renal tubular injury during cardiopulmonary bypass as assessed by urinary release of N-acetyl-ss-D-glucosaminidase
- 2017
-
Ingår i: Acta Anaesthesiologica Scandinavica. - : Wiley. - 0001-5172. ; 61:9, s. 1075-1083
-
Tidskriftsartikel (refereegranskat)abstract
- BackgroundAcute kidney injury (AKI) is a common complication with a major impact on morbidity and mortality after cardiac surgery with cardiopulmonary bypass (CPB). The aim of the present study was to perform a detailed analysis on the release of the tubular injury biomarker N-acetyl-b-D-glucosaminidase (NAG) during and early after CPB and to describe independent predictors of maximal tubular injury. We hypothesized that renal tubular injury occurs early after the onset of CPB. MethodsIn this prospective observational study, we included 61 patients undergoing open cardiac surgery with an expected CPB duration exceeding 60min. The urinary NAG levels were measured at 30min intervals during CPB, as well as early (30min) after CPB and post-operatively. Independent predictors of tubular injury were identified using an Interquantile multivariate regression model. ResultsAlready 30min after the onset of CPB, NAG excretion was significantly increased (P<0.001), followed by a sixfold peak increase after discontinuation of CPB (P<0.001). In the multivariable regression model, CPB duration (P<0.05) and the degree of rewarming during CPB (P<0.05), were independent predictors of peak NAG excretion. ConclusionIn cardiac surgery, a renal tubular cell injury is seen early after onset of CPB with a peak biomarker increase early after end of CPB. The magnitude of this tubular injury is independently related to CPB duration and the degree of rewarming. Efforts made to decrease the CPB duration and to avoid hypothermia and the need for rewarming may decrease the risk for tubular injury.
|
|
| 11. |
- Redfors, Bengt, et al.
(författare)
-
Acute renal failure is NOT an "acute renal success"--a clinical study on the renal oxygen supply/demand relationship in acute kidney injury.
- 2010
-
Ingår i: Critical Care Medicine. - 1530-0293. ; 38:8, s. 1695-701
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: Acute kidney injury occurs frequently after cardiac or major vascular surgery and is believed to be predominantly a consequence of impaired renal oxygenation. However, in patients with acute kidney injury, data on renal oxygen consumption (RVO2), renal blood flow, glomerular filtration, and renal oxygenation, i.e., the renal oxygen supply/demand relationship, are lacking and current views on renal oxygenation in the clinical situation of acute kidney injury are presumptive and largely based on experimental studies. DESIGN: Prospective, two-group comparative study. SETTING: Cardiothoracic intensive care unit of a tertiary center. PATIENTS: Postcardiac surgery patients with (n = 12) and without (n = 37) acute kidney injury were compared with respect to renal blood flow, glomerular filtration, RVO2, and renal oxygenation. INTERVENTIONS: None MEASUREMENTS AND MAIN RESULTS: Data on systemic hemodynamics (pulmonary artery catheter) and renal variables were obtained during two 30-min periods. Renal blood flow was measured using two independent techniques: the renal vein thermodilution technique and the infusion clearance of paraaminohippuric acid, corrected for renal extraction of paraaminohippuric acid. The filtration fraction was measured by the renal extraction of Cr-EDTA and the renal sodium resorption was measured as the difference between filtered and excreted sodium. Renal oxygenation was estimated from the renal oxygen extraction. Cardiac index and mean arterial pressure did not differ between the two groups. In the acute kidney injury group, glomerular filtration (-57%), renal blood flow (-40%), filtration fraction (-26%), and sodium resorption (-59%) were lower, renal vascular resistance (52%) and renal oxygen extraction (68%) were higher, whereas there was no difference in renal oxygen consumption between groups. Renal oxygen consumption for one unit of reabsorbed sodium was 2.4 times higher in acute kidney injury. CONCLUSIONS: Renal oxygenation is severely impaired in acute kidney injury after cardiac surgery, despite the decrease in glomerular filtration and tubular workload. This was caused by a combination of renal vasoconstriction and tubular sodium resorption at a high oxygen demand.
|
|
| 12. |
- Redfors, Bengt, et al.
(författare)
-
Dopamine increases renal oxygenation: a clinical study in post-cardiac surgery patients.
- 2010
-
Ingår i: Acta Anaesthesiol Scand. - : Wiley. - 1399-6576. ; 54:2, s. 183-90
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Imbalance of the renal medullary oxygen supply/demand relationship can cause ischaemic acute renal failure (ARF). The use of dopamine for prevention/treatment of ischaemic ARF has been questioned. It has been suggested that dopamine may increase renal oxygen consumption (RVO(2)) due to increased solute delivery to tubular cells, which may jeopardize renal oxygenation. Information on the effects of dopamine on renal perfusion, filtration and oxygenation in man is, however, lacking. We evaluated the effects of dopamine on renal blood flow (RBF), glomerular filtration rate (GFR), RVO(2) and renal O(2) demand/supply relationship, i.e. renal oxygen extraction (RO(2)Ex). METHODS: Twelve uncomplicated, mechanically ventilated and sedated post-cardiac surgery patients with pre-operatively normal renal function were studied. Dopamine was sequentially infused at 2 and 4 ug/kg/min. Systemic haemodynamics were evaluated by a pulmonary artery catheter. Absolute RBF was measured using two independent techniques: by the renal vein thermodilution technique and by infusion clearance of paraaminohippuric acid (PAH), with a correction for renal extraction of PAH. The filtration fraction (FF) was measured by the renal extraction of (51)Cr-EDTA. RESULTS: Neither GFR, tubular sodium reabsorption nor RVO(2) was affected by dopamine, which increased RBF (45-55%) with both methods, decreased renal vascular resistance (30-35%), FF (21-26%) and RO(2)Ex (28-34%). The RBF/CI ratio increased with dopamine. Dopamine decreased renal PAH extraction, suggestive of a flow distribution to the medulla. CONCLUSIONS: In post-cardiac surgery patients, dopamine increases the renal oxygenation by a pronounced renal pre-and post-glomerular vasodilation with no increases in GFR, tubular sodium reabsorption or renal oxygen consumption.
|
|
| 13. |
- Redfors, Bengt, et al.
(författare)
-
Effects of norepinephrine on renal perfusion, filtration and oxygenation in vasodilatory shock and acute kidney injury.
- 2011
-
Ingår i: Intensive Care Medicine. - : Springer Science and Business Media LLC. - 1432-1238 .- 0342-4642. ; 37:1, s. 60-7
-
Tidskriftsartikel (refereegranskat)abstract
- The use of norepinephrine (NE) in patients with volume-resuscitated vasodilatory shock and acute kidney injury (AKI) remains the subject of much debate and controversy. The effects of NE-induced variations in mean arterial blood pressure (MAP) on renal blood flow (RBF), oxygen delivery (RDO(2)), glomerular filtration rate (GFR) and the renal oxygen supply/demand relationship (renal oxygenation) in vasodilatory shock with AKI have not been previously studied.
|
|
| 14. |
- Ricksten, Sven-Erik, 1953, et al.
(författare)
-
Renal oxygenation in clinical acute kidney injury.
- 2013
-
Ingår i: Critical care (London, England). - : Springer Science and Business Media LLC. - 1466-609X .- 1364-8535. ; 17:2
-
Tidskriftsartikel (refereegranskat)
|
|
| 15. |
- Singh, P., et al.
(författare)
-
Renal oxygenation and haemodynamics in acute kidney injury and chronic kidney disease
- 2013
-
Ingår i: Clinical and Experimental Pharmacology and Physiology. - : Wiley. - 0305-1870 .- 1440-1681. ; 40:2, s. 138-147
-
Tidskriftsartikel (refereegranskat)abstract
- Acute kidney injury (AKI) is a major burden on health systems and may arise from multiple initiating insults, including ischaemia-reperfusion injury, cardiovascular surgery, radiocontrast administration and sepsis. Similarly, the incidence and prevalence of chronic kidney disease (CKD) continues to increase, with significant morbidity and mortality. Moreover, an increasing number of AKI patients survive to develop CKD and end-stage renal disease. Although the mechanisms for the development of AKI and progression to CKD remain poorly understood, initial impairment of oxygen balance likely constitutes a common pathway, causing renal tissue hypoxia and ATP starvation that, in turn, induce extracellular matrix production, collagen deposition and fibrosis. Thus, possible future strategies for one or both conditions may involve dopamine, loop diuretics, atrial natriuretic peptide and inhibitors of inducible nitric oxide synthase, substances that target kidney oxygen consumption and regulators of renal oxygenation, such as nitric oxide and heme oxygenase-1.
|
|
| 16. |
|
|
| 17. |
- Skytte Larsson, Jenny, et al.
(författare)
-
Renal Blood Flow, Glomerular Filtration Rate, and Renal Oxygenation in Early Clinical Septic Shock
- 2018
-
Ingår i: Critical Care Medicine. - : Ovid Technologies (Wolters Kluwer Health). - 0090-3493. ; 46:6
-
Tidskriftsartikel (refereegranskat)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.
|
|
| 18. |
- Skytte Larsson, Jenny, et al.
(författare)
-
Renal effects of norepinephrine-induced variations in mean arterial pressure after liver transplantation: A randomized cross-over trial
- 2018
-
Ingår i: Acta Anaesthesiologica Scandinavica. - : Wiley. - 0001-5172. ; 62:9, s. 1229-1236
-
Tidskriftsartikel (refereegranskat)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.
|
|
| 19. |
- Skytte Larsson, Jenny, et al.
(författare)
-
Renal function and oxygenation are impaired early after liver transplantation despite hyperdynamic systemic circulation.
- 2017
-
Ingår i: Critical Care. - : Springer Science and Business Media LLC. - 1364-8535 .- 1466-609X. ; 21:1
-
Tidskriftsartikel (refereegranskat)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.
|
|
