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Background: Cerebral blood flow (CBF) is believed to be relatively constant within an upper and lower blood pressure limit. Different methods are available to monitor CBF autoregulation during surgery. This study aims to critically analyze the application of the cerebral oxygenation index (COx), one of the commonly used techniques, using a reference to data from a series of clinical registrations. Method: CBF was monitored using near-infrared spectroscopy, while cerebral blood pressure was estimated by recordings obtained from either the radial or femoral artery in 10 patients undergoing cardiopulmonary bypass. The association between CBF and blood pressure was calculated as a moving continuous correlation coefficient. A COx index > 0.4 was regarded as a sign of abnormal cerebral autoregulation (CA). Recordings were examined to discuss reliability measures and clinical feasibility of the measurements, followed by interpretation of individual results, identification of possible pitfalls, and suggestions of alternative methods. Results and Conclusion: Monitoring of CA during cardiopulmonary bypass is intriguing and complex. A series of challenges and limitations should be considered before introducing this method into clinical practice.

Objective: Postoperative delirium (POD) is common after cardiac surgery. We have previously identified plasma sodium concentration and the volume of infused fluids during surgery as possible risk factors. Both are linked to the selection and composition of the pump prime used for cardiopulmonary bypass (CPB). Present study aims to examine whether hyperosmolality increases the risk for POD. Design: Patients ≥65 years (n = 195) scheduled for cardiac surgery were prospectively enrolled into this double blinded randomised clinical trial. Study group received a pump prime containing mannitol and ringer-acetate (966 mOsmol) (n = 98) vs. ringer-acetate (388 mOsmol) (n = 97) in the control group. Postoperative delirium was defined according to DSM-5 criteria based on a test-battery pre- and postoperatively (days 1–3). Plasma osmolality was measured on five occasions and coordinated with the POD assessments. The primary outcome was the POD incidence related to hyperosmolality as the secondary outcome. Results: The incidence of POD was 36% in the study group and 34% in the control group, without intergroup difference (p=.59). The plasma osmolality was significantly higher in the study group, both on days 1 and 3 and after CPB (p<.001). Post hoc analysis indicated that high osmolality levels increased the risk for delirium on day 1 by 9% (odds ratio (OR) 1.09, 95% CI 1.03–1.15) and by 10% on day 3 (OR 1.10, 95% CI 1.04–1.16). Conclusions: Use of a prime solution with high osmolality did not increase the incidence of POD. However, the influence of hyperosmolality as a risk factor for POD warrants further investigation. [ABSTRACT FROM AUTHOR]

Introduction: The study objective was to investigate whether a Ringer's acetate based priming solution with addition of Mannitol and sodium concentrate increases the risk of cardiac surgery associated kidney injury (CSA-AKI)., Methods: This is a double blind, prospective randomized controlled trial from a single tertiary teaching hospital in Sweden including patients aged ≥65 years ( n = 195) admitted for routine cardiac surgery with cardiopulmonary bypass. Patients in the study group received Ringer's acetate 1000 mL + 400 mL Mannitol (60 g) + sodium chloride 40 mL (160 mmol) and heparin 2 mL (10 000 IU) 966 mOsmol ( n = 98), while patients in the control group received Ringer's acetate 1400 mL + heparin 2 mL (10 000 IU), 388 mOsmol ( n = 97) as pump prime. Acute kidney injury was analysed based on the Kidney Disease Improving Outcomes (KDIGO 1-3) definition., Results: The overall incidence of CSA-AKI (KDIGO stage 1) was 2.6% on day 1 in the ICU and 5.6% on day 3, postoperatively. The serum creatinine level did not show any postoperative intergroup differences, when compared to baseline preoperative values. Six patients in the Ringer and five patients in the Mannitol group developed CSA-AKI (KDIGO 1-3), all with glomerular filtration rates <60 mL/min/1.73 m 2 . These patients showed significantly higher plasma osmolality levels compared to preoperative values. Hyperosmolality together with patient age and the duration of the surgery were independent risk factors for postoperative acute kidney injury (KDIGO 1-3)., Conclusions: The use of a hyperosmolar prime solution did not increase the incidence of postoperative CSA-AKI in this study, while high plasma osmolality alone increased the associated risk by 30%. The data suggests further examination of plasma hyperosmolality as a relative risk factor of CSA-AKI., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article. FundingThe author(s) received no financial support for the research, authorship, and/or publication of this article.

Background: Patients with preoperative dual antiplatelet therapy prior to coronary artery bypass surgery are at risk of bleeding and blood component transfusion. We hypothesise that an optimised cardiopulmonary bypass strategy reduces postoperative blood loss and transfusions., Methods: In total, 60 patients admitted for coronary artery bypass grafting with ticagrelor and aspirin medication withdrawn <96 hours before surgery were prospectively randomised into two equal sized groups. Cardiopulmonary bypass combined a closed Cortiva ® heparin-coated circuit with low systemic heparinisation (activated clotting time < 250 seconds) and intraoperative cell salvage in the study group, whereas the control group used a Balance ® coated open circuit, full systemic heparinisation (activated clotting time > 480 seconds) and conventional cardiotomy suction. This perfusion strategy was evaluated by the chest drain volume after 24 hours, perioperative haemoglobin and platelet loss accompanied by global coagulation assessments., Results: Patients in the study group demonstrated significantly better outcomes signified by lower blood loss 554 ± 224 versus 1,100 ± 989 mL (p < 0.001), reduced packed red cell transfusion 7% versus 53% (p < 0.001), reduced haemoglobin -28 ± 15 versus -40 ± 14 g/L (p = 0.004) and platelet loss -35 ± 36 versus -82 ± 67 × 10 9 /L (p = 0.001). Indices of rotational thromboelastometry indicated shorter clotting times within the internal and external pathways. Adenosine diphosphate activated platelet function was within normal range based on Multiplate ® aggregometry, while ROTEM ® platelet analyses indicated inhibited function both preoperatively and post-bypass. Platelet inhibition by aspirin was verified throughout the perioperative period. Platelet function showed no intergroup differences., Conclusion: A stringent perfusion strategy reduced blood loss and transfusions in dual antiplatelet therapy patients requiring urgent surgery.

Introduction: In the literature addressing cardiopulmonary bypass (CPB) prime composition, there is a considerable lack of discussion concerning plasma osmolality changes induced by using a hyperosmolar prime. With this study, we try to determine the magnitude and temporal relationship of plasma osmolality changes related to the use of a hyperosmolar CPB prime., Method: In this prospective observational study performed in a university hospital setting, we enrolled thirty patients scheduled for elective coronary bypass surgery. Plasma osmolality was analysed on eight occasions. A hyperosmolar CPB prime was used., Results: Analyses of the perioperative plasma osmolality on eight occasions gave the following results: the preoperative osmolality level was normal (297±4 mOsm/kg); a significant increase to 322±17 mOsm/kg (p<0.001) was observed at the commencement of CPB and remained elevated after 30 minutes (310±4 mOsm/kg) and throughout the procedure (309±4 mOsm/kg); the osmolality level returned to 291±5 mOsm/kg on day 1 postoperatively and remained normal the following day (291±6 mOsm/kg)., Conclusions: Use of hyperosmolar CPB prime resulted in a dramatic and instant elevation of the plasma osmolality. Rapid changes in plasma osmolality are associated with organ dysfunction (e.g. osmotic demyelination syndrome), therefore, effects on plasma osmolality related to the CPB prime composition should be recognised. Influence on organ function and clinical outcome warrants further investigations. - Clinical Trials.gov (NCT03060824). Changes in Plasma Osmolality Related to the Use of Cardiopulmonary Bypass With Hyperosmolar Prime. URL: https://clinicaltrials.gov/ct2/show/NCT03060824?term=cpb&cond=osmolality&rank=1.

Objective: To establish a statistical model for determination of protamine dose in conjunction with cardiopulmonary bypass., Design: Prospective., Setting: University hospital., Participants: Ninety consecutive cardiac surgical patients., Interventions: None., Measurements and Main Results: A series of clinically oriented variables were introduced into a statistical model for projection of the protamine dose after cardiopulmonary bypass. The following significant predictors were identified using multivariable regression analysis: The patient's body surface area, the administered dose of heparin, heparin clearance, and the preoperative platelet count. The statistical model projected the protamine dose within 3±23 mg of the point-of-care test used as reference., Conclusion: Protamine dosing based on statistical modeling represents an alternative to point-of-care tests., (Copyright © 2015 Elsevier Inc. All rights reserved.)