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- Brix-Christensen, V., et al.
(författare)
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Plasma cytokines do not reflect expression of pro- and anti-inflammatory cytokine mRNA at organ level after cardiopulmonary bypass in neonatal pigs.
- 2003
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Ingår i: Acta Anaesthesiologica Scandinavica. - : Wiley. - 0001-5172. ; 47:5, s. 525-531
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Tidskriftsartikel (refereegranskat)abstract
- Background: Plasma concentrations of inflammatory markers are increased in response to the trauma of cardiac surgery and cardiopulmonary bypass (CPB). It is, however, unknown whether the plasma cytokine levels and cytokine mRNA expression at organ level reflect each other. Methods: Twenty-six piglets (17–19 days) were allocated to the sham-group (sternotomy only, n = 13) or to the CPB-group (sternotomy, 120 min CPB procedure with 60-min aortic cross-clamp, n = 13). The pigs were observed for 0.5 h or 4 h post-CPB. Plasma levels of IL-1β, IL-6, IL-8 and IL-10 and mRNA expression of TNF-α, IL-1β, IL-6, IL-8, IL-10 and iNOS in organs were registered with concomitant changes in oxygenation index (OI) and expiratory nitric oxide (NO). Results: In pigs killed 0.5 h post-CPB there was a significant increase in IL-10 mRNA in the lungs and kidneys compared with the sham-group. IL-1β mRNA was detectable in the kidneys and lungs of the CPB-pigs, while IL-6 mRNA was up regulated only in lungs. In pigs killed 4 h post-CPB a significantly higher IL-6 mRNA was found in heart tissue and a lower IL-10 mRNA was found in lungs of CPB pigs compared with the sham-group. There was a concomitant significant increase in OI and increased plasma IL-8 and IL-10 concentrations in the CPB-pigs compared with the sham-pigs. Conclusion: The cytokine mRNA expression pattern was very different for the pigs killed already 0.5 h after the CPB procedure compared with the pigs killed 4 h post-CPB. The plasma cytokine levels poorly reflected mRNA expression of the pro- and anti-inflammatory cytokines.
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| 2. |
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| 3. |
- Chew, Michelle
(författare)
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Does modified ultrafiltration reduce the systemic inflammatory response to cardiac surgery with cardiopulmonary bypass?
- 2004
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Ingår i: Perfusion. - : SAGE Publications. - 1477-111X .- 0267-6591. ; 19 Suppl 1, s. 57-60
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Tidskriftsartikel (refereegranskat)abstract
- Cardiopulmonary bypass (CPB) is associated with an accumulation of total body water and a systemic inflammatory response syndrome (SIRS), which, in turn, is associated with organ dysfunction and postoperative morbidity. It has been suggested that modified ultrafiltration (MUF) may be capable of reducing SIRS and improving clinical outcome by filtering out the inflammatory mediators generated during CPB. This paper reviews the data regarding the use of MUF in paediatric and adult settings. Specifically, three issues will be considered: 1) Does MUF improve clinical outcome? 2) Does MUF reduce the systemic inflammatory response to cardiac surgery with CPB? 3) Is MUF more effective than conventional ultrafiltration in improving clinical outcome?
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| 4. |
- Chew, Michelle, et al.
(författare)
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Doppler flow measurement using surface integration of velocity vectors (Sivv) : in vitro validation
- 2000
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Ingår i: Ultrasound in Medicine and Biology. - 0301-5629 .- 1879-291X. ; 26:2, s. 255-262
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Tidskriftsartikel (refereegranskat)abstract
- Blood flow measurement using an improved surface integration of velocity vectors (SIVV) technique was tested in in vitro phantoms. SIVV was compared with true flow (12–116 mL/s) in a steady-state model using two angles of insonation (45° and 60°) and two vessel sizes (internal diameter = 11 and 19 mm). Repeatability of the method was tested at various flow rates for each angle of insonation and vessel. In a univentricular pulsatile model, SIVV flow measured at the mitral inlet was compared to true flow (29–61 mL/s). Correlation was excellent for the 19-mm vessel (r2= 0.99). There was a systematic bias but close limits of agreement (mean ± 2 SD = −24.1% ± 7.6% at 45 °; +16.4% ± 11.0% at 60 °). Using the 11-mm vessel, a quadratic relationship was demonstrated between between SIVV and true flow (r2 = 0.98–0.99), regardless of the angle of insonation. In the pulsatile system, good agreement and correlation were shown (r2 = 0.94, mean ± 2 SD = −4.7 ± 10.1%). The coefficients of variation for repeated SIVV measurements ranged from 0.9% to 10.3%. This method demonstrates precision and repeatability, and is potentially useful for clinical measurements.
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| 5. |
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| 6. |
- Chew, Michelle, et al.
(författare)
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Pediatric cardiac output measurement using surface integration of velocity vectors : an in vivo validation study
- 2000
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Ingår i: Critical Care Medicine. - : Ovid Technologies (Wolters Kluwer Health). - 0090-3493 .- 1530-0293. ; 28:11, s. 3664-3671
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To test the accuracy and reproducibility of systemic cardiac output (CO) measurements using surface integration of velocity vectors (SIVV) in a pediatric animal model with hemodynamic instability and to compare SIVV with traditional pulsed-wave Doppler measurements.Design: Prospective, comparative study.Setting: Animal research laboratory at a university medical center.Subjects: Eight piglets weighing 10-15 kg.Interventions: Hemodynamic instability was induced by using inhalation of isoflurane and infusions of colloid and dobutamine.Measurements: SIVV CO was measured at the left ventricular outflow tract, the aortic valve, and ascending aorta. Transit time CO was used as the reference standard.Results: There was good agreement between SIVV and transit time CO. At high frame rates, the mean difference ± 2 sd between the two methods was 0.01 ± 0.27 L/min for measurements at the left ventricular outflow tract, 0.08 ± 0.26 L/min for the ascending aorta, and 0.06 ± 0.25 L/min for the aortic valve. At low frame rates, measurements were 0.06 ± 0.25, 0.19 ± 0.32, and 0.14 ± 0.30 L/min for the left ventricular outflow tract, ascending aorta, and aortic valve, respectively. There were no differences between the three sites at high frame rates. Agreement between pulsed-wave Doppler and transit time CO was poorer, with a mean difference ± 2 sd of 0.09 ± 0.93 L/min. Repeated SIVV measurements taken at a period of relative hemodynamic stability differed by a mean difference ±2 sd of 0.01 ± 0.22 L/min, with a coefficient of variation = 7.6%. Intraobserver coefficients of variation were 5.7%, 4.9%, and 4.1% at the left ventricular outflow tract, ascending aorta, and aortic valve, respectively. Interobserver variability was also small, with a coefficient of variation = 8.5%.Conclusions: SIVV is an accurate and reproducible flow measurement technique. It is a considerable improvement over currently used methods and is applicable to pediatric critical care.
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