| 1. |
- Bartfay, Sven-Erik, et al.
(author)
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Are biventricular assist devices underused as a bridge to heart transplantation in patients with a high risk of postimplant right ventricular failure?
- 2017
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In: Journal of Thoracic and Cardiovascular Surgery. - : Elsevier BV. - 0022-5223 .- 1097-685X. ; 153:2
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Journal article (peer-reviewed)abstract
- Right ventricular failure in patients treated using left ventricular assist devices is associated with poor outcomes. We assessed the strategy of preplanned biventricular assist device implantation in patients with a high risk for right ventricular failure.Between 2010 and 2014, we assigned 20 patients to preplanned biventricular assist device and 21 patients to left ventricular assist device as a bridge to heart transplantation on the basis of the estimated risk of postimplant right ventricular failure. Preimplant characteristics and postimplant outcomes were compared between the 2 groups.Patients with a biventricular assist device were younger, more often female, and more frequently had nonischemic heart disease than left ventricular assist device recipients. At preoperative assessment, biventricular assist device recipients had poorer Interagency Registry for Mechanically Assisted Circulatory Support profiles, a lower cardiac index, and more compromised right ventricular function. Survival on device to heart transplantation/weaning/destination for biventricular assist device and left ventricular assist device recipients was 90% versus 86% (not significant), with shorter heart transplantation waiting times for biventricular assist device recipients (median days, 154 vs 302, P<.001). Overall survival at 1year was 85% (95% confidence interval, 62-95) versus 86% (95% confidence interval, 64-95) (not significant). The majority of both biventricular assist device and left ventricular assist device recipients could be discharged to home during the heart transplantation waiting time (55% vs 71%, not significant), and complication rates on device were comparable between groups (major stroke 10% vs 10%, not significant).Planned in advance, the biventricular assist device seems to be a feasible option as bridge to heart transplantation for patients with a high risk of postimplant right ventricular failure. The outcomes for these patients were similarto those observed for contemporary left ventricular assist device recipients, despite those receiving biventricular assist devices being more severely ill.
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| 2. |
- Bartfay, Sven-Erik, et al.
(author)
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Durable circulatory support with a paracorporeal device as an option for pediatric and adult heart failure patients.
- 2021
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In: The Journal of thoracic and cardiovascular surgery. - : Elsevier BV. - 1097-685X .- 0022-5223. ; 161:4
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Journal article (peer-reviewed)abstract
- Not all patients in need of durable mechanical circulatory support are suitable for a continuous-flow left ventricular assist device. We describe patient populations who were treated with the paracorporeal EXCOR, including children with small body sizes, adolescents with complex congenital heart diseases, and adults with biventricular failure.Information on clinical data, echocardiography, invasive hemodynamic measurements, and surgical procedures were collected retrospectively. Differences between various groups were compared.Between 2008 and 2018, a total of 50 patients (21 children and 29 adults) received an EXCOR as bridge to heart transplantation or myocardial recovery. The majority of patients had heart failure compatible with Interagency Registry for Mechanically Assisted Circulatory Support profile 1. At year 5, the overall survival probability for children was 90%, and for adults 75% (P=.3). After we pooled data from children and adults, the survival probability between patients supported by a biventricular assist device was similar to those treated with a left ventricular assist device/ right ventricular assist device (94% vs 75%, respectively, P=.2). Patients with dilated cardiomyopathy had a trend toward better survival than those with other heart failure etiologies (92% vs 70%, P=.05) and a greater survival free from stroke (92% vs 64%, P=.01). Pump house exchange was performed in nine patients due to chamber thrombosis (n=7) and partial membrane rupture (n=2). There were 14 cases of stroke in eleven patients.Despite severe illness, patient survival on EXCOR was high, and the long-term overall survival probability following heart transplantation and recovery was advantageous. Treatment safety was satisfactory, although still hampered by thromboembolism, mechanical problems, and infections.
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| 3. |
- Bragadottir, Gudrun, et al.
(author)
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Assessing glomerular filtration rate (GFR) in critically ill patients with acute kidney injury - true GFR versus urinary creatinine clearance and estimating equations.
- 2013
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In: Critical care (London, England). - : Springer Science and Business Media LLC. - 1466-609X .- 1364-8535. ; 17:3
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Journal article (peer-reviewed)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.
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| 4. |
- Bragadottir, Gudrun, et al.
(author)
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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
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In: Critical care medicine. - 1530-0293. ; 41:10, s. 2328-2335
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Journal article (peer-reviewed)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.
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| 5. |
- Bragadottir, Gudrun, et al.
(author)
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Low-dose vasopressin increases glomerular filtration rate, but impairs renal oxygenation in post-cardiac surgery patients.
- 2009
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In: Acta Anaesthesiol Scand. - : Wiley. - 1399-6576. ; 53:8, s. 1052-9
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Journal article (peer-reviewed)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.
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| 6. |
- Bragadottir, Gudrun, et al.
(author)
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Mannitol increases renal blood flow and maintains filtration fraction and oxygenation in postoperative acute kidney injury: a prospective interventional study.
- 2012
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In: Critical Care. - : Springer Science and Business Media LLC. - 1364-8535 .- 1466-609X. ; 16:4
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Journal article (peer-reviewed)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.
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| 7. |
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| 8. |
- Drevinge, Christina, 1983, et al.
(author)
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Perilipin 5 is protective in the ischemic heart
- 2016
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In: International Journal of Cardiology. - : Elsevier BV. - 0167-5273 .- 1874-1754. ; 219, s. 446-454
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Journal article (peer-reviewed)abstract
- Background: Myocardial ischemia is associated with alterations in cardiac metabolism, resulting in decreased fatty acid oxidation and increased lipid accumulation. Here we investigate how myocardial lipid content and dynamics affect the function of the ischemic heart, and focus on the role of the lipid droplet protein perilipin 5 (Plin5) in the pathophysiology of myocardial ischemia. Methods and results: We generated Plin5(-/-) mice and found that Plin5 deficiency dramatically reduced the triglyceride content in the heart. Under normal conditions, Plin5(-/-) mice maintained a close to normal heart function by decreasing fatty acid uptake and increasing glucose uptake, thus preserving the energy balance. However, during stress or myocardial ischemia, Plin5 deficiency resulted in myocardial reduced substrate availability, severely reduced heart function and increased mortality. Importantly, analysis of a human cohort with suspected coronary artery disease showed that a common noncoding polymorphism, rs884164, decreases the cardiac expression of PLIN5 and is associated with reduced heart function following myocardial ischemia, indicating a role for Plin5 in cardiac dysfunction. Conclusion: Our findings indicate that Plin5 deficiency alters cardiac lipid metabolism and associates with reduced survival following myocardial ischemia, suggesting that Plin5 plays a beneficial role in the heart following ischemia. (C) 2016 The Authors. Published by Elsevier Ireland Ltd.
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| 9. |
- Granklint Enochson, Pernilla, 1965-
(author)
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Om organsystemens organisation och funktion : analys av elevsvar från Sverige och Sydafrika
- 2012
-
Doctoral thesis (other academic/artistic)abstract
- Syftet med denna avhandling är att studera svenska och sydafrikanska elevers föreställningar om kroppens byggnad och funktion, samt hur dessa föreställningar påverkar närliggande frågeställningar. Datainsamling har skett genom att flera olika typer av enkäter samt intervjuer använts. Samtliga elever som deltog gick i årskurs nio. Det var 88 elever i den svenska och 166 i den Sydafrikanska datainsamlingen.Resultaten visar att elever har en god förmåga att beskriva matspjälkningssystemet då de beskriver en smörgås väg genom kroppen, och de visar även god förmåga att koppla samman blodsystemet till matspjälkningsorganen för detta scenario. Däremot har eleverna svårigheter att överföra denna kunskap till ett nytt sammanhang då de skulle beskriva en värktabletts väg genom kroppen. Eleverna hade inte fått undervisning om värktablettens väg genom kroppen, så detta var ett nytt sammanhang för dem. Det visade sig vara än svårare för eleverna att koppla samman ytterligare ett organsystem, det vill säga urinorganen, när de skulle beskriva vattnets väg genom kroppen. Trots att urinorganen finns beskrivna i läroboken och eleverna hade fått undervisning om dessa. Det fanns också elever som visade icke vetenskapligt vedertagna modeller och beskrev vattnets väg genom kroppen genom att rita ett rör direkt från halsen till njuren. Dessa elever kunde inte beskriva njuren främsta funktion som är att rena blodet. En liknande studie genomfördes i fem Sydafrikanska skolor och det visade sig att den i Sverige, och i andra europeiska studier, vanliga icke vetenskapliga förklaringen med en direktkoppling mellan matspjälkningsorganen och njurarna var mycket ovanlig bland dessa elever. Nästan hälften av de sydafrikanska eleverna visade istället en föreställning om att vattnet passerar lungorna på sin väg till magsäcken. Det fanns även mindre mängd elever som även ansåg att maten skulle passera lungorna innan magsäcken. När det gäller vattenfrågan har en djupare analys gjorts på 5 av de svenska elevernas enkät- och intervjusvar. Det visade sig att elevernas föreställningar antingen var desamma eller förändrades till en mindre sofistikerad förklaringsmodell mellan enkät och intervjusvar då det gällde vattnets väg genom kroppen, detta skiljer sig från frågeställningen med smörgåsen där intervjun visade på liknande eller bättre resultat.
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| 10. |
- Granklint Enochson, Pernilla
(author)
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Om organsystemens organisation och funktion– analys av elevsvar från Sverige och Sydafrika : analys av elevsvar från Sverige och Sydafrika
- 2012
-
Doctoral thesis (other academic/artistic)abstract
- Syftet med denna avhandling är att studera svenska och sydafrikanska elevers föreställningar om kroppens byggnad och funktion, samt hur dessa föreställningar påverkar närliggande frågeställningar. Datainsamling har skett genom att flera olika typer av enkäter samt intervjuer använts. Samtliga elever som deltog gick i årskurs nio. Det var 88 elever i den svenska och 166 i den Sydafrikanska datainsamlingen. Resultaten visar att elever har en god förmåga att beskriva matspjälkningssystemet då de beskriver en smörgås väg genom kroppen, och de visar även god förmåga att koppla samman blodsystemet till matspjälkningsorganen för detta scenario. Däremot har eleverna svårigheter att överföra denna kunskap till ett nytt sammanhang då de skulle beskriva en värktabletts väg genom kroppen. Eleverna hade inte fått undervisning om värktablettens väg genom kroppen, så detta var ett nytt sammanhang för dem. Det visade sig vara än svårare för eleverna att koppla samman ytterligare ett organsystem, det vill säga urinorganen, när de skulle beskriva vattnets väg genom kroppen. Trots att urinorganen finns beskrivna i läroboken och eleverna hade fått undervisning om dessa. Det fanns också elever som visade icke vetenskapligt vedertagna modeller och beskrev vattnets väg genom kroppen genom att rita ett rör direkt från halsen till njuren. Dessa elever kunde inte beskriva njuren främsta funktion som är att rena blodet. En liknande studie genomfördes i fem Sydafrikanska skolor och det visade sig att den i Sverige, och i andra europeiska studier, vanliga icke vetenskapliga förklaringen med en direktkoppling mellan matspjälkningsorganen och njurarna var mycket ovanlig bland dessa elever. Nästan hälften av de sydafrikanska eleverna visade istället en föreställning om att vattnet passerar lungorna på sin väg till magsäcken. Det fanns även mindre mängd elever som även ansåg att maten skulle passera lungorna innan magsäcken. När det gäller vattenfrågan har en djupare analys gjorts på 5 av de svenska elevernas enkät- och intervjusvar. Det visade sig att elevernas föreställningar antingen var desamma eller förändrades till en mindre sofistikerad förklaringsmodell mellan enkät och intervjusvar då det gällde vattnets väg genom kroppen, detta skiljer sig från frågeställningen med smörgåsen där intervjun visade på liknande eller bättre resultat.
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| 11. |
- Henningsson, Anna, et al.
(author)
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Prehospital monitoring of cerebral circulation during out of hospital cardiac arrest ? : A feasibility study
- 2022
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In: Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine. - : Springer Science and Business Media LLC. - 1757-7241. ; 30:1
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Journal article (peer-reviewed)abstract
- BackgroundAbout two-thirds of the in-hospital deaths after out-of-hospital cardiac arrests (OHCA) are a consequence of anoxic brain injuries, which are due to hypoperfusion of the brain during the cardiac arrests. Being able to monitor cerebral perfusion during cardiopulmonary resuscitation (CPR) is desirable to evaluate the effectiveness of the CPR and to guide further decision making and prognostication.MethodsTwo different devices were used to measure regional cerebral oxygen saturation (rSO2): INVOS™ 5100 (Medtronic, Minneapolis, MN, USA) and Root® O3 (Masimo Corporation, Irvine, CA, USA). At the scene of the OHCA, advanced life support (ALS) was immediately initiated by the Emergency Medical Services (EMS) personnel. Sensors for measuring rSO2 were applied at the scene or during transportation to the hospital. rSO2 values were documented manually together with ETCO2 (end tidal carbon dioxide) on a worksheet specially designed for this study. The study worksheet also included a questionnaire for the EMS personnel with one statement on usability regarding potential interference with ALS.ResultsTwenty-seven patients were included in the statistical analyses. In the INVOS™5100 group (n = 13), the mean rSO2 was 54% (95% CI 40.3–67.7) for patients achieving a return of spontaneous circulation (ROSC) and 28% (95% CI 12.3–43.7) for patients not achieving ROSC (p = 0.04). In the Root® O3 group (n = 14), the mean rSO2 was 50% (95% CI 46.5–53.5) and 41% (95% CI 36.3–45.7) (p = 0.02) for ROSC and no ROSC, respectively. ETCO2 values were not statistically different between the groups. The EMS personnel graded the statement of interference with ALS to a median of 2 (IQR 1–6) on a 10-point Numerical Rating Scale.ConclusionOur results suggest that both INVOS™5100 and ROOT® O3 can distinguish between ROSC and no ROSC in OHCA, and both could be used in the pre-hospital setting and during transport with minimal interference with ALS.
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| 12. |
- Jamaly, Shabbar, 1965, et al.
(author)
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Prognostic significance of BMI after PCI treatment in ST-elevation myocardial infarction: a cohort study from the Swedish Coronary Angiography and Angioplasty Registry.
- 2021
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In: Open heart. - : BMJ. - 2053-3624. ; 8:1
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Journal article (peer-reviewed)abstract
- Obesity along with clustering of cardiovascular risk factors is a promoter for coronary artery disease. On the other hand, a high body mass index (BMI) appears to exert a protective effect with respect to outcomes after a coronary artery event, termed the obesity paradox.The Swedish Coronary Angiography and Angioplasty Registry collects information on all patients who undergo percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction (STEMI) in Sweden along with demographic and procedure-related data. We studied the predictability of four categories of BMI for 1-year all-cause mortality in people with STEMI undergoing PCI.Among 25384 patients, mean (SD) age 67.7 (12.1) years and 70.2% male, who underwent PCI for STEMI, a total of 5529 (21.8%) died within 1year. Using normal weight (BMI 18.5-24.9kg/m2) as a reference, subjects with obesity (BMI ≥30kg/m2) had a low 1-year all-cause mortality risk in unadjusted analysis, HR 0.59 (95% CI 0.53 to 0.67). However, after adjustment for age, sex and other covariates, the difference became non-significant, HR 0.88 (95% CI 0.75 to 1.02). Patients with overweight (BMI 25.0-29.9kg/m2) had the lowest 1-year mortality risk in analysis adjusted for age, sex and other covariates, HR 0.87 (95% CI 0.79 to 0.97), whereas those with underweight (BMI <18.5kg/m2) had the highest mortality in both unadjusted HR 2.22 (95% CI 1.69 to 2.92) and adjusted analysis, HR 1.62 (95% CI 1.18 to 2.23).The protective effect of obesity with respect to 1-year mortality after coronary intervention became non-significant after adjusting for age, sex and relevant covariates. Instead, overweight people displayed the lowest risk and underweight individuals the highest risk for adjusted all-cause mortality.NCT02311231.
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| 13. |
- Lannemyr, Lukas, 1974, et al.
(author)
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Effects of Cardiopulmonary Bypass on Renal Perfusion, Filtration, and Oxygenation in Patients Undergoing Cardiac Surgery.
- 2017
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In: Anesthesiology. - 1528-1175. ; 126:2, s. 205-213
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Journal article (peer-reviewed)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.
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| 14. |
- Lannemyr, Lukas, 1974, et al.
(author)
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Effects of milrinone on renal perfusion, filtration and oxygenation in patients with acute heart failure and low cardiac output early after cardiac surgery
- 2020
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In: Journal of Critical Care. - : Elsevier BV. - 0883-9441. ; 57, s. 225-230
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Journal article (peer-reviewed)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.
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| 15. |
- Lannemyr, Lukas, 1974, et al.
(author)
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Impact of Cardiopulmonary Bypass Flow on Renal Oxygenation in Patients Undergoing Cardiac Operations
- 2019
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In: The Annals of thoracic surgery. - : Elsevier BV. - 1552-6259 .- 0003-4975. ; 107:2, s. 505-511
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Journal article (peer-reviewed)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.
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| 16. |
- Lannemyr, Lukas, 1974, et al.
(author)
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Renal tubular injury during cardiopulmonary bypass as assessed by urinary release of N-acetyl-ss-D-glucosaminidase
- 2017
-
In: Acta Anaesthesiologica Scandinavica. - : Wiley. - 0001-5172. ; 61:9, s. 1075-1083
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Journal article (peer-reviewed)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.
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| 17. |
- Nygren, Andreas, 1967, et al.
(author)
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Norepinephrine causes a pressure-dependent plasma volume decrease in clinical vasodilatory shock.
- 2010
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In: Acta anaesthesiologica Scandinavica. - : Wiley. - 1399-6576 .- 0001-5172. ; 54:7, s. 814-20
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Journal article (peer-reviewed)abstract
- BACKGROUND: Recent experimental studies have shown that a norepinephrine-induced increase in blood pressure induces a loss of plasma volume, particularly under increased microvascular permeability. We studied the effects of norepinephrine-induced variations in the mean arterial pressure (MAP) on plasma volume changes and systemic haemodynamics in patients with vasodilatory shock. METHODS: Twenty-one mechanically ventilated patients who required norepinephrine to maintain MAP > or =70 mmHg because of septic/postcardiotomy vasodilatory shock were included. The norepinephrine dose was randomly titrated to target MAPs of 60, 75 and 90 mmHg. At each target MAP, data on systemic haemodynamics, haematocrit, arterial and mixed venous oxygen content and urine flow urine were measured. Changes in the plasma volume were calculated as 100 x (Hct(pre)/Hct(post)-1)/ (1-Hct(pre)), where Hct(pre) and Hct(post) are haematocrits before and after intervention. RESULTS: Norepinephrine doses to obtain target MAPs of 60, 75 and 90 mmHg were 0.20+/-0.18, 0.29+/-0.18 and 0.42+/-0.31 microg/kg/min, respectively. From 60 to 90 mmHg, increases in the cardiac index (15%), systemic oxygen delivery index (25%), central venous pressure (CVP) (20%) and pulmonary artery occlusion pressure (33%) were seen, while the intrapulmonary shunt fraction was unaffected by norepinehrine. Plasma volume decreased by 6.5% and 9.4% (P<0.0001) when blood pressure was increased from 60 to 75 and 90 mmHg, respectively. MAP (P<0.02) independently predicted the decrease in plasma volume with norepinephrine but not CVP (P=0.19), cardiac index (P=0.73), norepinephrine dose (P=0.58) or urine flow (P=0.64). CONCLUSIONS: Norepinephrine causes a pressure-dependent decrease in the plasma volume in patients with vasodilatory shock most likely caused by transcapillary fluid extravasation.
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| 18. |
- Redfors, Bengt, et al.
(author)
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Acute renal failure is NOT an "acute renal success"--a clinical study on the renal oxygen supply/demand relationship in acute kidney injury.
- 2010
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In: Critical Care Medicine. - 1530-0293. ; 38:8, s. 1695-701
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Journal article (peer-reviewed)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.
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| 19. |
- Redfors, Bengt, et al.
(author)
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Dopamine increases renal oxygenation: a clinical study in post-cardiac surgery patients.
- 2010
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In: Acta Anaesthesiol Scand. - : Wiley. - 1399-6576. ; 54:2, s. 183-90
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Journal article (peer-reviewed)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.
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| 20. |
- Redfors, Bengt, et al.
(author)
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Effects of mannitol alone and mannitol plus furosemide on renal oxygen consumption, blood flow and glomerular filtration after cardiac surgery.
- 2009
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In: Intensive care medicine. - : Springer Science and Business Media LLC. - 1432-1238 .- 0342-4642. ; 35:1, s. 115-22
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Journal article (peer-reviewed)abstract
- OBJECTIVE: Imbalance of the renal medullary oxygen supply/demand relationship can cause hypoxic medullary damage and ischaemic acute renal failure (ARF). The use of mannitol for prophylaxis/treatment of clinical ischaemic ARF is controversial and the effect of mannitol on renal oxygenation in man has not yet been investigated. We evaluated the effects of mannitol on renal oxygen consumption (RVO(2))(,) renal blood flow (RBF) and glomerular filtration rate (GFR) in postoperative patients. DESIGN: Prospective interventional study. SETTING: University hospital cardiothoracic ICU. PATIENTS: Ten uncomplicated mechanically ventilated and sedated postcardiac surgery patients with preoperatively normal renal function. INTERVENTIONS: Mannitol infusion (225 mg/kg + 75 mg/kg/h) and combined mannitol and furosemide infusion (0.25 mg/kg + 0.25 mg/kg/h). MEASUREMENTS AND RESULTS: Systemic haemodynamics were evaluated by a pulmonary artery catheter. RBF and GFR were measured by the renal vein thermodilution technique and by renal extraction of (51)Cr-EDTA, respectively. Mannitol increased urine flow (60%), GFR (20%) and filtration fraction (FF) (20%) with no change in RBF. This was accompanied by an increase in renal sodium reabsorption (18%), RVO(2) (19%) and renal oxygen extraction (21%). When combined with mannitol, furosemide normalised sodium reabsorption, RVO(2), renal oxygen extraction with no change in RBF, while GFR and FF were still elevated compared to control. CONCLUSIONS: In patients with normal renal function, mannitol increases GFR, which increases tubular sodium load, sodium reabsorption and RVO(2) after cardiac surgery. The lack of effect on RBF, indicates that mannitol impairs the renal oxygen supply/demand relationship. Furosemide normalised renal oxygenation when combined with mannitol.
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| 21. |
- Redfors, Bengt, et al.
(author)
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Effects of norepinephrine on renal perfusion, filtration and oxygenation in vasodilatory shock and acute kidney injury.
- 2011
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In: Intensive Care Medicine. - : Springer Science and Business Media LLC. - 1432-1238 .- 0342-4642. ; 37:1, s. 60-7
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Journal article (peer-reviewed)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.
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| 22. |
- Redfors, Bengt
(author)
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Prevention and treatment of acute kidney injury after cardiac surgery.
- 2010
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Doctoral thesis (other academic/artistic)abstract
- Acute kidney injury (AKI) occurs frequently after cardiac surgery and is independently associated with increased mortality. The main cause of AKI in these patients is renal ischemia. However, data on the renal oxygenation, defined as the renal oxygen supply/demand relationship are lacking in clinical AKI, and the effects of various pharmacological interventions on renal oxygenation are not known. Patients and methods: The effects of mannitol (n=10) and dopamine (n=12) on renal blood flow (RBF... mer), glomerular filtration rate (GFR) and renal oxygenation were analysed in post-cardiac surgery patients using the renal vein thermodilution technique. Furthermore, RBF, GFR and renal oxygenation were studied in patients with AKI (n=12) and compared to postoperative patients with no renal impairment (n=37). Finally, the effects of norepinephrine-induced changes in mean arterial pressure (MAP) on renal variables were analysed in AKI patients (n=12) with vasodilatory shock. Results: Mannitol increased GFR and the renal oxygen demand (RVO2), while it had no effect on RBF. Mannitol, thus, pharmacologically improved the renal function at the cost of an impaired renal oxygenation. In contrast, dopamine redistributed blood flow to the kidney and increased RBF, but had no effect on GFR or RVO2. Consequently, dopamine improved renal oxygenation. AKI patients had a 40% lower RBF and a 60 % lower net-sodium reabsorption and GFR compared to control patients. However, contrary to previous hypothesis, this decrease in reabsorptive workload was not accompanied with a decrease in RVO2. Thus, renal oxygenation was severely impaired in AKI. The high RVO2 correlated directly to the sodium reabsorption, consuming 2.4 times more oxygen for a certain amount of reabsorbed sodium in AKI compared to control. Restoration of MAP from 60–75 mmHg with norepinephrine, improved renal oxygen delivery, GFR and renal oxygenation in AKI patients. Increasing MAP to 90 mmHg had no further beneficial effect. Conclusions: While mannitol improves GFR at the cost of an impaired renal oxygenation, dopamine, in contrast, improves renal oxygenation, but has no effect on GFR. Furthermore, renal oxygenation is severely impaired in AKI, due to renal vasoconstriction and sodium reabsorption at a high oxygen cost. Finally, norepinephrine improves GFR and renal oxygenation when used for treatment of hypotension.
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| 23. |
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| 24. |
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| 25. |
- Schultz, Tomas, 1972, et al.
(author)
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Stress-Induced Cardiomyopathy in Sweden: Evidence for Different Ethnic Predisposition and Altered Cardio-Circulatory Status
- 2012
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In: Cardiology. - : S. Karger AG. - 0008-6312 .- 1421-9751. ; 122:3, s. 180-186
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Journal article (peer-reviewed)abstract
- Background: In this paper, we report about new insights regarding clinical course, long-term outcome, ethnic/genetic predisposition and cardio-circulatory status in the large stress-induced cardiomyopathy (SIC) cohort from Sweden. Methods and Results: We have included 115 consecutive SIC patients between January 2005 and January 2010 at Sahlgrenska University Hospital in Gothenburg. Hemodynamic status and sympathetic nerve activity were evaluated and compared with those of healthy controls. Mean age was 64, and 14% were males. Thirty-day and 3-year mortality was 6 and 10%, respectively. Eleven percent had ischemic heart disease, 3% developed thromboembolic complications, 6% had cardiac arrest and 14% developed cardiogenic shock. The great majority of SIC patients (93%) were ethnic Swedes. In three families, several close relatives developed SIC. Fourteen percent developed two or more episodes of SIC. Hemodynamic evaluation has shown subnormal systemic vascular resistance, 22% lower sympathetic activity and preserved cardiac output in SIC patients. Conclusions: SIC affects both men and women of different ages and is associated with significant short- and long-term mortality. There is a strong signal for the presence of ethnic/genetic predisposition to develop SIC. Sympathetic activity and systemic vascular resistance are lower in SIC patients, suggesting that SIC is a cardio-circulatory phenomenon. Copyright (C) 2012 S. Karger AG, Basel
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| 26. |
- Singh, P., et al.
(author)
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Renal oxygenation and haemodynamics in acute kidney injury and chronic kidney disease
- 2013
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In: Clinical and Experimental Pharmacology and Physiology. - : Wiley. - 0305-1870 .- 1440-1681. ; 40:2, s. 138-147
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Journal article (peer-reviewed)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.
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| 27. |
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| 28. |
- 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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| 29. |
- 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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| 30. |
- 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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| 31. |
- Sultanian, Pedram, et al.
(author)
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Prediction of survival in out-of-hospital cardiac arrest: the updated Swedish cardiac arrest risk score (SCARS) model
- 2024
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In: EUROPEAN HEART JOURNAL - DIGITAL HEALTH. - 2634-3916.
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Journal article (peer-reviewed)abstract
- Aims Out-of-hospital cardiac arrest (OHCA) is a major health concern worldwide. Although one-third of all patients achieve a return of spontaneous circulation and may undergo a difficult period in the intensive care unit, only 1 in 10 survive. This study aims to improve our previously developed machine learning model for early prognostication of survival in OHCA.Methods and results We studied all cases registered in the Swedish Cardiopulmonary Resuscitation Registry during 2010 and 2020 (n = 55 615). We compared the predictive performance of extreme gradient boosting (XGB), light gradient boosting machine (LightGBM), logistic regression, CatBoost, random forest, and TabNet. For each framework, we developed models that optimized (i) a weighted F1 score to penalize models that yielded more false negatives and (ii) a precision-recall area under the curve (PR AUC). LightGBM assigned higher importance values to a larger set of variables, while XGB made predictions using fewer predictors. The area under the curve receiver operating characteristic (AUC ROC) scores for LightGBM were 0.958 (optimized for weighted F1) and 0.961 (optimized for a PR AUC), while for XGB, the scores were 0.958 and 0.960, respectively. The calibration plots showed a subtle underestimation of survival for LightGBM, contrasting with a mild overestimation for XGB models. In the crucial range of 0-10% likelihood of survival, the XGB model, optimized with the PR AUC, emerged as a clinically safe model.Conclusion We improved our previous prediction model by creating a parsimonious model with an AUC ROC at 0.96, with excellent calibration and no apparent risk of underestimating survival in the critical probability range (0-10%). The model is available at www.gocares.se.
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