| 1. |
- Alström, Ulrica, et al.
(författare)
-
Platelet inhibition assessed with VerifyNow, flow cytometry and PlateletMapping in patients undergoing heart surgery
- 2009
-
Ingår i: Thrombosis Research. - : Elsevier BV. - 0049-3848 .- 1879-2472. ; 124:5, s. 572-577
-
Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: A substantial number of patients with coronary artery disease undergo cardiac surgery within five days of discontinuing anti-platelet treatment with aspirin and clopidogrel. The aims of this study were to describe the degree of platelet inhibition in patients with dual anti-platelet treatment scheduled for coronary artery bypass graft (CABG) surgery and to investigate whether the measured platelet inhibition correlated to intra- and postoperative risk for bleeding and transfusion requirements. MATERIAL AND METHODS: Sixty patients were included. Platelet inhibition was analysed with flow cytometry including phosphorylation status of the vasodilator-stimulated phosphoprotein (VASP-assay) and two bed-side analyzers, VerifyNow-System and PlateletMapping, a modified thrombelastograph. All 60 patients were analysed with VerifyNow and PlateletMapping, and 48 were analysed with flow cytometry and VASP-assay. RESULTS: There was a correlation between the ADP-receptor inhibition as measured by VASP-assay and VerifyNowP2Y(12) (r = -0.29, p<0.05), and between VASP-assay and the expression of P-selectin (r = 0.29, p<0.05) as measured by flow cytometry when platelets were stimulated with 5 microM ADP. VerifyNowP2Y(12) was the only measurement of platelet inhibition correlated to total blood loss (Spearman r = 0.29, p=0.03) and red blood cell transfusion (Spearman r = 0.43, p<0.01) requirements, although this might be confounded by aprotinin treatment. CONCLUSION: We found a modest agreement between the methods for preoperative platelet inhibition, though not for PlateletMapping-MA(ADP). There was a correlation between preoperative platelet inhibition measured by VerifyNowP2Y(12) and surgical blood loss or transfusion requirements. However, for the individual patient, preoperative use of VerifyNowP2Y(12) as an instrument to decide bleeding and transfusion risk does not seem helpful.
|
|
| 2. |
- Alström, Ulrica, et al.
(författare)
-
The platelet inhibiting effect of a clopidogrel bolus dose in patients on long-term acetylsalicylic acid treatment
- 2007
-
Ingår i: Thrombosis Research. - : Elsevier BV. - 0049-3848 .- 1879-2472. ; 120:3, s. 353-359
-
Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Addition of clopidogrel to patients treated with ASA has been shown to decrease the incidence of in-stent thrombosis after percutaneous coronary interventions. However, it has also been reported that up to 30% of patients do not achieve adequate platelet inhibition from standard dosages of ASA and clopidogrel. There is a demand for reliable methods to measure the individual platelet inhibiting effect of this combination therapy. MATERIALS AND METHODS: The primary aim of the present investigation was to compare three methods for evaluation of the platelet inhibiting effect of a clopidogrel bolus dose in patients on long-term acetylsalicylic acid treatment. Thirty patients presenting for coronary angiography/PCI were included. Two patients were excluded due to technical problems. All patients were on 75-100 mg ASA/day for at least 8 days. Blood samples were analysed before and 16 h after a 300 mg clopidogrel bolus dose. The platelet inhibiting effect was measured with (1) Whole blood flow cytometry (17 patients); (2) a bed-side test, Platelet Mapping assay for the thrombelastograph (28 patients); and (3) PFA (Platelet function analyser) -100 (26 patients). RESULTS: With flow cytometry, the percentage of platelets expressing P-selectin (p=0.03) on their surface decreased significantly after the bolus dose of clopidogrel. There was also a reduction of platelets binding fibrinogen when stimulated with ADP. A significantly (p=0.002) increased platelet inhibition could also be demonstrated with Platelet Mapping. PFA-100 could not measure any significant platelet inhibiting effect of clopidogrel. CONCLUSION: A significant platelet inhibition could be demonstrated with flow cytometry and the Platelet Mapping assay, but not with PFA-100. However, levels of response for the individual patient with these three methods were inconsistent. Further studies are needed to evaluate how the results correlate to the clinical risk of thrombosis and bleeding.
|
|
| 3. |
- Axelsson, Birger, 1957-
(författare)
-
Cardiac effects of non-adrenergic inotropic drugs : clinical and experimental studies
- 2013
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Myocardial failure and dysfunction is not uncommon during critical illness and following cardiac surgery. For optimal treatment, a better understanding of the effects of inotropic drugs is needed. In this thesis, two non-adrenergic mediated inotropes, milrinone and levosimendan were studied in different models of myocardial dysfunction. The study aims were to assess the following: the effects of milrinone on blood flow in coronary artery bypass grafts during CABG surgery; the effects of milrinone on left ventricular diastolic function during post-ischaemic myocardial dysfunction; whether milrinone or levosimendan are protective or injurious during acute myocardial ischaemia, and if levosimendan potentiates myocardial function when added to milrinone in an experimental model of post-ischaemic (stunned) myocardium.Material and Methods: In Study I, 44 patients undergoing coronary artery bypass surgery(CABG) were included as subjects. Milrinone or saline was administrated in a single dose during cardio-pulmonary bypass (CPB) and coronary graft flow measurements were recorded after 10 and 30 min following CPB. In Study II; 24 patients undergoing CABG had estimations of peak ventricular filling rates made before and after CPB with administration of milrinone or saline as a single dose during CPB, performed by assessment of the rate of change in diastolic cross-sectional left ventricular area. In Study III, energy-metabolic effects of milrinone and levosimendan were measured in an anaesthetized porcine model during 45 minutes of regional myocardial ischemia. Microdialysis sampling of metabolites of local ischemic metabolism allowed assessment of glycolytic activity and the degree of myocardial calcium overload. In Study IV, in a porcine model of postischaemic myocardial stunning, ventricular pressure-volume relationships were analyzed when milrinone or a combination of milrinone and levosimendan were given together.Results: In Study I, there was a clear increase in non-sequential saphenous vein graft blood flow with milrinone at 10 minutes (64.5 ± 37.4 compared to placebo 43.6 ± 25.7 ml/min (mean ± SD).). A decreasing but still measureable flow increase was seen for milrinone at 30 minutes. In Study II, an increase in early left ventricular filling rate (ventricular cross-sectional area rate of change,dA/dt) was seen in the milrinone treated group. Pre-bypass milrinone group dA/dt 22.0 ± 9.5 changed to post-bypass values dA/dt 27.8 ± 11.5 cm2/sec). Placebo group pre-bypass dA/dt was 21.0 ± 8.7 and post-bypass 17.1 ± 7.1 cm2/sec. A milrinone effect was demonstrated in an adjusted regression model (p = 0.001). In Study III, neither milrinone nor levosimendan led to a change in energy-metabolic activity during ischemia as reflected by interstitial glucose, pyruvate, lactate orglycerol. Neither drug exacerbated the relative myocardial calcium overload during ischemia. In Study IV, milrinone improved active relaxation (tau) in post-ischemic stunned myocardium, but did not markedly improve systolic function by preload recruitable stroke work. Levosimendan added to milrinone showed minimal effect on active relaxation but a positive effect on systolic function in combination with milrinone.Conclusions: We conclude that milrinone treatment leads to an increase in blood flow in newly implanted coronary saphenous vein grafts, and improves ventricular relaxation post-cardiopulmonary bypass. Neither milrinone nor levosimendan, in this porcine model, negatively influence myocardial energy metabolism or calcium overload during acute ischaemia. Addition of levosimendan to milrinone treatment during post-ischaemic ventricular dysfunction may provide additive inotropic effects on systolic function but probably not for active relaxation.
|
|
| 4. |
- Axelsson, Birger, 1957-, et al.
(författare)
-
Effects of Combined Milrinone and Levosimendan Treatment on Systolic and Diastolic Function During Postischemic Myocardial Dysfunction in a Porcine Model
- 2016
-
Ingår i: Journal of Cardiovascular Pharmacology and Therapeutics. - Thousand Oaks, USA : Sage Publications. - 1074-2484 .- 1940-4034. ; 21:5, s. 495-503
-
Tidskriftsartikel (refereegranskat)abstract
- It is not known whether there are positive or negative interactions on ventricular function when a calcium-sensitizing inotrope is added to a phosphodiesterase inhibitor in the clinical setting of acute left ventricular (LV) dysfunction. We hypothesized that when levosimendan is added to milrinone treatment, there will be synergetic inotropic and lusitropic effects. This was tested in an anesthetized porcine postischemic global LV injury model, where ventricular pressures and volumes (conductance volumetry) were measured. A global ischemic injury was induced by repetitive left main stem coronary artery occlusions. Load-independent indices of LV function were assessed before and after ventricular injury, after milrinone treatment, and finally after addition of levosimendan to the milrinone treatment. Nonparametric, within-group comparisons were made. The protocol was completed in 12 pigs, 7 of which received the inotrope treatment and 5 of which served as controls. Milrinone led to positive lusitropic effects seen by improvement in tau after myocardial stunning. The addition of levosimendan to milrinone further increased lusitropic state. The latter effect could however not be attributed solely to levosimendan, since lusitropic state also improved spontaneously in time-matched controls at the same rate during the corresponding period. When levosimendan was added to milrinone infusion, there was no increase in systolic function (preload recruitable stroke work) compared to milrinone treatment alone. We conclude that in this model of postischemic LV dysfunction, there appears to be no clear improvement in systolic or diastolic function after addition of levosimendan to established milrinone treatment but also no negative effects of levosimendan in this context.
|
|
| 5. |
|
|
| 6. |
- Bogatic, Wirginia, 1969-
(författare)
-
Exilens dilemma: att stanna eller att återvända : Beslut i Sverige av polska kvinnor som överlevde KZ-lägret Ravensbrück och räddades till Sverige 1945-1947
- 2010
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis is about the intersection of great narratives and individual decisions. In the intersection, the dilemma of exile is discussed: to remain in exile or return to one’s homeland. The decision to remain or return was made by the surviving Polish female concentration camp prisoners that were brought back to Sweden in 1945 with the Red Cross rescue operation.The women’s decisions have been contextualized by being placed against the political, social and economic upheavals that took place primarily in Poland, but also partly in Sweden, as well as in the international environment with which the new Poland had to form a relationship following the Second World War.The thesis moves between three levels: the micro level, comprising the individuals, their choices and experiences; the macro level, including the surrounding social, economic and political structures; the meso level, which merges the individual, her network and the state. The theoretical framework is on the one hand based on Reinhart Koselleck’s concepts of “realm of experience” and “expectations” that structure the time horizon and refer to the universal, and on the other hand, the sociological concept of generations and Svante Lundberg's model of exile with the concepts of Circumstance, Frame and Meaning. Both Koselleck and Lundberg focus on the individual / group and structural context. Sources used have been material from the Swedish Government and the two Polish governments and their agencies. In addition, a number of Polish and Swedish newspapers published during the period 1945-1947 as well as material from the Polish Source Institute in Lund (PIZ) have been studied. Thirteen in-depth interviews with the surviving women (both in Poland and Sweden) have been carried out, resulting in so-called life stories, with the objective of providing an answer to the question of why some of them remained in Sweden after the war while others returned to Poland. In the women's life stories, some themes can be distinguished: the common realm of experience, being adherent to the same sociological generation with a manifest collective memory (which in part developed differently depending on their decisions to remain or return), a link between war and captivity and expectations for the future. Otherwise, the life stories highlight the women's construction of identity, which is affected by growing up in the between-war Poland, the time during World War II and the occupation. It also reveals that these experiences influenced their decision: remaining and returning.
|
|
| 7. |
|
|
| 8. |
- Jideus, Lena, et al.
(författare)
-
Thoracic epidural anesthesia does not influence the occurrence of postoperative sustained atrial fibrillation
- 2001
-
Ingår i: Annals of Thoracic Surgery. - 0003-4975 .- 1552-6259. ; 72:1, s. 65-71
-
Tidskriftsartikel (refereegranskat)abstract
- Background. To evaluate whether thoracic epidural anesthesia (TEA) can reduce the incidence of atrial fibrillation (AF) after coronary artery bypass grafting (CABG).Methods. Forty-one patients undergoing CABG were treated with TEA intraoperatively and postoperatively. Another 80 patients served as the control group. The sympathetic and parasympathetic activities were evaluated by analysis of neuropeptides, catecholamines and heart rate variability (HRV), preoperatively and postoperatively.Results. Postoperative AF occurred in 31.7% of the TEA-treated patients and in 36.3% of the untreated patients (p = 0.77). TEA significantly suppressed sympathetic activity, as indicated by a less pronounced increase of norepinephrine and epinephrine (p = 0.03, p = 0.02) and a significant decrease of neuropeptide Y (p = 0.01) postoperatively in TEA-treated patients compared to untreated patients. The HRV variable expressing sympathetic activity was significantly lower and the postoperative increase in heart rate was significantly less in the TEA group than in the control group after surgery (p = 0.01, p < 0.001). Among patients developing AF, the maximal number of supraventricular premature beats per minute increased significantly in untreated patients postoperatively but remained unchanged in TEA-treated patients (p = 0.004 versus p = 0.86).Conclusions. TEA has no effect on the incidence of postoperative sustained AF, despite a significant reduction in sympathetic activity.
|
|
| 9. |
- Linde, Torbjörn, et al.
(författare)
-
The use of pretransplant erythropoietin to normalize hemoglobin levels has no deleterious effects on renal transplantation outcome
- 2001
-
Ingår i: Transplantation. - : Ovid Technologies (Wolters Kluwer Health). - 0041-1337 .- 1534-6080. ; 71:1, s. 79-82
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The aim of this study was to establish the outcome of renal transplantation in patients given pretransplant erythropoietin (EPO) treatment targeted at reaching a normal hemoglobin concentration (Hb), compared to those given EPO-treatment aimed at maintaining subnormal Hb. METHODS: A total of 416 patients from Scandinavian countries and with renal anaemia were enrolled to examine the effects of increasing Hb from a subnormal level (90-120 g/liter) to a normal level (135-160 g/liter) by EPO treatment. Half of the patients were randomized to have their Hb increased, with the other half randomized to maintain a subnormal Hb. Thirty-two patients from the normal Hb group and 24 patients from the subnormal group received a renal graft during the study period. The outcomes of these transplantations were examined prospectively for 6 months. RESULTS: Preoperative Hb levels were 143+/-17 and 121+/-14 g/liter in the two groups, respectively (P<0.0001). The Hb remained higher in the normal Hb group during the first 2 weeks after transplantation. The percentage of patients requiring postoperative blood transfusions in the normal Hb group was 16%, compared with 50% in the subnormal group (P<0.01). No statistically significant difference in the proportion of functioning grafts or in the serum creatinine levels could be detected. No correlation between EPO treatment and creatinine levels after transplantation was found. The frequency of adverse events was similar in the two groups. CONCLUSIONS: EPO treatment aimed at reaching a normal Hb in renal transplant recipients reduces the postoperative requirement for blood transfusions and has no deleterious effects on kidney graft function.
|
|
| 10. |
- Magnusson, Lennart, et al.
(författare)
-
Atelectasis is a major cause of hypoxemia and shunt after cardiopulmonary bypass : An experimental study
- 1997
-
Ingår i: Anesthesiology. - 0003-3022 .- 1528-1175. ; 87:5, s. 1153-1163
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Respiratory failure after cardiopulmonary bypass (CPB) remains a major complication after cardiac surgery. The authors tested the hypothesis that atelectasis is an important factor responsible for the increase in intrapulmonary shunt after CPB. METHODS: Six pigs received standard CPB (bypass group). Six other pigs had the same surgery but without CPB (sternotomy group). Another six pigs were anesthetized for the same duration but without any surgery (control group). The ventilation-perfusion distribution was measured with the inert gases technique, extravascular lung water was quantified by the double-indicator distribution technique, and atelectasis was analyzed by computed tomography. RESULTS: Intrapulmonary shunt increased markedly after bypass but was unchanged over time in the control group (17.9 +/- 6.2% vs. 3.5 +/- 1.2%; P < 0.0001). Shunt also increased in the sternotomy group (10 +/- 2.6%; P < 0.01 compared with baseline) but was significantly lower than in the bypass group (P < 0.01). Extravascular lung water was not significantly altered in any group. The pigs in the bypass group showed extensive atelectasis (32.3 +/- 28.7%), which was significantly larger than in the two other groups. The pigs in the sternotomy group showed less atelectasis (4.1 +/- 1.9%) but still more (P < 0.05) than the controls (1.1 +/- 1.6%). There was good correlation between shunt and atelectasis when all data were pooled (R2 = 0.67; P < 0.0001). CONCLUSIONS: Atelectasis is produced to a much larger extent after CPB than after anesthesia alone or with sternotomy and it explains most of the marked post-CPB increase in shunt and hypoxemia. Surgery per se contributes to a lesser extent to postoperative atelectasis and gas exchange impairment.
|
|
