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Tranexamic acid reduces blood loss and transfusion requirements with no significant thrombotic adverse effects. Postoperative seizures have been seen in cardiac surgical patients in association with patient (advanced age, underlying neurologic disease, chronic kidney disease); surgical (open cardiac procedures, long bypass times); and drug (high tranexamic acid dose) risk factors. Tranexamic acid dosing regimens should be decreased in patients with chronic kidney dysfunction secondary to reduced clearance and drug accumulation. Optimal dosing for cardiac surgical patients has been recommended. Additional research is required to determine dosing regimens in major noncardiac surgery and plasma concentration levels associated with inducing seizures., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Cerebral oxygen desaturation during cardiac surgery has been associated with adverse perioperative outcomes. Before a large multicenter randomized controlled trial (RCT) on the impact of preventing desaturations on perioperative outcomes, the authors undertook a randomized prospective, parallel-arm, multicenter feasibility RCT to determine whether an intervention algorithm could prevent desaturations., Methods: Eight Canadian sites randomized 201 patients between April 2012 and October 2013. The primary outcome was the success rate of reversing cerebral desaturations below 10% relative to baseline in the intervention group. Anesthesiologists were blinded to the cerebral saturation values in the control group. Intensive care unit personnel were blinded to cerebral saturation values for both groups. Secondary outcomes included the area under the curve of cerebral desaturation load, enrolment rates, and a 30-day follow-up for adverse events., Results: Cerebral desaturations occurred in 71 (70%) of the 102 intervention group patients and 56 (57%) of the 99 control group patients (P = 0.04). Reversal was successful in 69 (97%) of the intervention group patients. The mean cerebral desaturation load (SD) in the operating room was smaller for intervention group patients compared with control group patients (104 [217] %.min vs. 398 [869] %.min, mean difference, -294; 95% CI, -562 to -26; P = 0.03). This was also true in the intensive care unit (P = 0.02). There were no differences in adverse events between the groups., Conclusions: Study sites were successful in reversal of desaturation, patient recruitment, randomization, and follow-up in cardiac surgery, supporting the feasibility of conducting a large multicenter RCT.

Background: The aim of this paper is to describe clinical management in a situation where patient has experienced anaphylaxis while undergoing surgical septal myectomy for hypertrophic obstructive cardiomyopathy (HOCM)., Case Report: A 40-yr-old female was scheduled to undergo surgical septal myectomy for the treatment of HOCM. After induction, the patient developed refractory hypotension that did not respond to escalating doses of vasopressors and volume therapy. Although a clinical examination led to the diagnosis of anaphylaxis, epinephrine, which is the usual treatment of choice, failed to improve the patient's haemodynamics. A transesophageal echocardiography revealed a worsening of left ventricular outflow tract obstruction (LVOTO) after epinephrine administration. In the end, the rapid institution of a cardiopulmonary bypass was required as a rescue therapy instead of to save a patient., Conclusion: The anaesthetic goals in a patient in HOCM are to maintain preload and afterload and to avoid stimulation of inotropy and chronotropy to leading to left ventricular outflow obstruction. In a patient with anaphylaxis, maintaining these haemodynamic goals becomes much more difficult since the pathophysiology and usual treatment of choice will worsen LVOTO. Special consideration for the need to have extracorporeal life support to treat refractory hypotension in surgical patients with HOCM may be warranted.

This systematic review and meta-analysis appraises the utility of point-of-care platelet function tests for predicting blood loss and transfusion requirements in cardiac surgical patients, and analyses whether their use within a transfusion management algorithm is associated with improved patient outcomes. We included 30 observational studies incorporating 3044 patients in the qualitative assessment, and nine randomised controlled trials including 1057 patients in the meta-analysis. Platelet function tests demonstrated significant variability in their ability to predict blood loss and transfusion requirements. Their use within a blood transfusion algorithm demonstrated a reduction in blood loss at longest follow-up (mean difference -102.9 ml (95% CI -149.9 to -56.1 ml), p < 0.001), and transfusion of packed red cells (RR 0.86 (95% CI 0.78-0.94), p = 0.001) and fresh frozen plasma (RR 0.42 (95% CI 0.30-0.59), p < 0.001). Viscoelastic methods used in combination with other platelet function tests achieved greater reduction in blood loss (mean difference -111.8 ml (95% CI -174.9 to -49.1 ml), p = 0.0005) compared with their use alone (mean difference -90.6 ml (95% CI 166.1-15.0 ml), p = 0.02). We conclude that incorporation of point-of-care platelet function tests into transfusion management algorithms is associated with a reduction in blood loss and transfusion requirements in cardiac surgery patients., (© 2015 The Association of Anaesthetists of Great Britain and Ireland.)

Because of a lack of contemporary data regarding seizures after cardiac surgery, we undertook a retrospective analysis of prospectively collected data from 11 529 patients in whom cardiopulmonary bypass was used from January 2004 to December 2010. A convulsive seizure was defined as a transient episode of disturbed brain function characterised by abnormal involuntary motor movements. Multivariate regression analysis was performed to identify independent predictors of postoperative seizures. A total of 100 (0.9%) patients developed postoperative convulsive seizures. Generalised and focal seizures were identified in 68 and 32 patients, respectively. The median (IQR [range]) time after surgery when the seizure occurred was 7 (6-12 [1-216]) h and 8 (6-11 [4-18]) h, respectively. Epileptiform findings on electroencephalography were seen in 19 patients. Independent predictors of postoperative seizures included age, female sex, redo cardiac surgery, calcification of ascending aorta, congestive heart failure, deep hypothermic circulatory arrest, duration of aortic cross-clamp and tranexamic acid. When tested in a multivariate regression analysis, tranexamic acid was a strong independent predictor of seizures (OR 14.3, 95% CI 5.5-36.7; p < 0.001). Patients with convulsive seizures had 2.5 times higher in-hospital mortality rates and twice the length of hospital stay compared with patients without convulsive seizures. Mean (IQR [range]) length of stay in the intensive care unit was 115 (49-228 [32-481]) h in patients with convulsive seizures compared with 26 (22-69 [14-1080]) h in patients without seizures (p < 0.001). Convulsive seizures are a serious postoperative complication after cardiac surgery. As tranexamic acid is the only modifiable factor, its administration, particularly in doses exceeding 80 mg.kg(-1), should be weighed against the risk of postoperative seizures.

Purpose: Administrative electronic databases are highly specific for postoperative complications, but they lack sensitivity. The objective of this study was to determine the incidence of delirium after cardiac surgery using a targeted prospectively collected dataset and to compare the findings with the incidence of delirium in the same cohort of patients identified in a hospital administrative database., Methods: Following Research Ethics Board approval, we compared delirium rates in a prospectively collected data research database with delirium rates in the same cohort of patients in an administrative hospital database where delirium was identified from codes entered by coding and abstracting staff. Every 12 hr postoperatively, delirium was assessed with a Confusion Assessment Method in the Intensive Care Unit. The administrative database contained the International Classification of Diseases version 10 (ICD-10) codes for patient diagnoses. The ICD-10 codes were extracted from the administrative database for each patient in the research database and were checked for the presence of the ICD-10 code for delirium., Results: Data from a cohort of 1,528 patients were analyzed. Postoperative delirium was identified in 182 (11.9%) patients (95% confidence interval [CI], 10.3-13.5%) in the research dataset and 46 (3%) patients (95% CI, 2.2-3.8%) in the administrative dataset (P < 0.001). Thirteen (0.85%) patients who were coded for delirium in the administrative database were not identified in the research dataset. The median onset of postoperative delirium in these patients was significantly delayed (4 [3-9] days) compared with patients identified by both datasets (2 [1-9] days) and compared with patients from the research database only (1 [1-14] days) (P = 0.007)., Conclusion: Postoperative delirium rates after cardiac surgery are underestimated by the hospital administrative database.

Background: Accurate risk stratification may help reduce the burden of excessive blood loss after cardiac surgery. We measured the incremental value of thrombelastography to an existing risk prediction model for excessive blood loss in cardiac surgery., Methods: This observational study included 434 patients who underwent cardiac surgery with cardiopulmonary bypass (CPB) and had thrombelastographic measures before and during CPB, their risk of excessive blood loss could be calculated with an existing risk prediction model and they had not received clopidogrel or warfarin within 5 days of surgery. Excessive blood loss was defined as transfusion of > or = 5 U of red blood cells from termination of CPB to 1 day after surgery. Logistic regression models including an existing risk prediction model without and with thrombelastographic measures were constructed. Improvement in risk prediction was measured by the area under the curve and net reclassification improvement., Results: Excessive blood loss occurred in 59 of 434 patients (13.6%). The only thrombelastographic measure that improved risk stratification was maximum amplitude during CPB, which reflects maximum clot strength. Although the addition of this variable to the existing prediction model did not have a material effect on the area under the curve (increased from 0.780 to 0.784; P = 0.8), it did improve the net reclassification improvement by 12% (P = 0.05), primarily by improving the detection of high-risk cases., Conclusions: Risk stratification for excessive blood loss after cardiac surgery is improved when on-CPB thrombelastography is added to an existing risk prediction model that incorporates readily available patient- and surgery-related variables, but large, multicenter trials are needed to verify this finding and create a new risk prediction model.

Objective: Recombinant activated factor VII (rFVIIa) is being increasingly used in cardiac surgical patients with refractory hemorrhage. In this study, the authors assessed the ability of thromboelastography (TEG) in guiding rFVIIa therapy in this setting., Design: Retrospective study., Setting: Tertiary care university hospital., Participants: Thirty-eight consecutive patients who received rFVIIa for refractory hemorrhage after cardiac surgery and had a complete coagulation profile including TEG within 30 minutes before and after rFVIIa., Interventions: Standard coagulation (prothrombin time, partial thromboplastin time, platelet number, and fibrinogen) and TEG measurements (r time, k time, alpha angle, and maximum amplitude) before and after rFVIIa therapy were compared between responders and nonresponders (determined retrospectively based on clinical records)., Measurements and Results: Twenty-eight patients (74%) were classified as responders. There were no consistent changes in standard coagulation and TEG measurements before and after rFVIIa therapy. The number of abnormalities in pretreatment coagulation tests was related to response rates; odds of response were 11-fold (95% confidence interval [CI]) and 33-fold (95% CI) greater among patients with 0 or 1 abnormality in standard coagulation tests and TEG measures, respectively, than those with 2 or more abnormalities., Conclusions: TEG may be a useful tool for predicting response to rFVIIa in the setting of refractory hemorrhage after cardiac surgery.

Purpose: Recombinant factor VIIa (rFVIIa) is being used for refractory, excessive blood loss (EBL) after cardiac surgery, but its safety for this indication is not known., Methods: The unadjusted and risk-adjusted adverse event (AE) rates were compared between 114 consecutive cardiac surgical patients who received rFVIIa for refractory EBL and 541 concurrent patients who developed EBL but did not receive rFVIIa. Similarly, timing of rFVIIa therapy was assessed by dichotomizing rFVIIa patients based on median number of red blood cell (RBC) units received before therapy. The measured AE was a composite of death, stroke, renal failure, myocardial infarction, and major vein thrombosis. For risk adjustment, logistic regression models for this outcome were constructed using known predictors of AEs., Results: The median RBC units transfused before rFVIIa therapy was eight. The AE rates in the untreated, early (< or = 8 U), and late (> 8 U) treated patients were 24% (129/541), 30% (20/66), and 60% (29/48). The risk-adjustment model included total RBC units, pump time, weaning difficulty, gender, weight, and age. The unadjusted and adjusted AE odds ratios (OR) in the treated vs untreated groups were 2.41 [confidence interval (CI) 1.58-3.67; P < 0.0001] and 1.04 (CI 0.60-1.81; P = 0.9). In the rFVIIa group, the adjusted AE OR was lower in the early treated group (OR 0.41; CI 0.18-0.92; P = 0.03)., Conclusion: In cardiac surgical patients with refractory hemorrhage, rFVIIa therapy is not associated with increased risk of AEs, and early treatment may be associated with better outcomes.

Purpose: To determine the independent relationship between leukoreduced platelet transfusions and adverse events in cardiac surgery., Methods: In this observational study, detailed baseline and perioperative data were prospectively collected on consecutive patients who underwent cardiac surgery at a single institution from 1999 to 2004. The independent associations of platelet transfusion with clinical outcomes (low output syndrome, myocardial infarction, stroke, renal failure, sepsis, and death) were determined by multivariable logistic regression analysis and propensity score case-control analysis., Results: Of the 11,459 patients analyzed, 2,174 (19%) received (leukoreduced) platelets - 1,408 received 5 U, 471 received 10 U, 140 received 15 U, and 155 received 20 or more units. Although all measured adverse event rates were higher in those who received platelets, in neither the logistic regression analyses nor the propensity score analyses was there any association between platelet transfusion and any of the adverse events., Conclusions: Transfusion of leukoreduced platelets in cardiac surgery is not associated with adverse clinical outcomes when adjustments are made for important confounders.