Impact of COVID-19 and lockdown regarding blood transfusion.

BACKGROUND: The outbreak of a SARS-CoV-2 resulted in a massive afflux of patients in hospital and intensive care units with many challenges. Blood transfusion was one of them regarding both blood banks (safety, collection, and stocks) and consumption (usual care and unknown specific demand of COVID-19 patients). The risk of mismatch was sufficient to plan blood transfusion restrictions if stocks became limited. STUDY DESIGN AND METHODS: Analyses of blood transfusion in a tertiary hospital and blood collection in the referring blood bank between February 24 and May 31, 2020. RESULTS: Withdrawal of elective surgery and non-urgent care and admission of 2291 COVID-19 patients reduced global activity by 33% but transfusion by 17% only. Only 237 (10.3) % of COVID-19 patients required blood transfusion, including 45 (2.0%) with acute bleeding. Lockdown and cancellation of mobile collection resulted in an 11% reduction in blood donation compared to 2019. The ratio of reduction in blood transfusion to blood donation remained positive and stocks were slightly enhanced. DISCUSSION: Reduction of admissions due to SARS-CoV-2 pandemic results only in a moderate decrease of blood transfusion. Incompressible blood transfusions concern urgent surgery, acute bleeding (including some patients with COVID-19, especially under high anticoagulation), or are supportive for chemotherapy-induced aplasia or chronic anemia. Lockdown results in a decrease of blood donation by cancellation of mobile donation but with little impact on a short period by mobilization of usual donors. No mismatch between demand and donation was evidenced and no planned restriction to blood transfusion was necessary.

Adjusted calculation model of heparin management during cardiopulmonary bypass in obese patients: A randomised controlled trial.

BACKGROUND: Anticoagulation during cardiopulmonary bypass (CPB) is usually adapted to total body weight (TBW). This may be inaccurate in obese patients and lead to heparin overdose with a risk of bleeding. OBJECTIVES: To validate the efficacy and safety of an adjusted calculation model of heparin dosing based on ideal body weight (IBW) rather than TBW in obese CPB patients, with an expected target mean plasma heparin concentration of 4.5 IU ml after onset of CPB in the experimental group. DESIGN: Randomised controlled study. SETTING: University hospital. PATIENTS: Sixty obese patients (BMI ≥ 30 kg m) scheduled for CPB were included from January to June 2016. INTERVENTIONS: Patients received a bolus dose of unfractionated heparin of either 300 IU kg of TBW or 340 IU kg of IBW before onset of CPB. Additional adjusted boluses were injected to maintain an activated clotting time (ACT) of at least 400 s. MAIN OUTCOME MEASURES: Plasma heparin concentration and ACT were measured at different time points. Total heparin doses and transfusion requirements were recorded. RESULTS: The target heparin concentration of 4.5 IU ml was reached in the IBW group at the onset of CPB and maintained at all time points during CPB. Heparin concentrations were significantly higher in the TBW group after the bolus (6.52 ±â€Š0.97 vs. 4.54 ±â€Š1.13 IU ml, P < 0.001) and after cardioplegia (5.10 ±â€Š1.03 vs. 4.31 ±â€Š1.00 IU ml, P = 0.02). Total heparin doses were significantly higher in the TBW group. Mean ACT was significantly lower in the IBW group but remained over 400 s during CPB. The correlation between heparin and ACT was poor. Peri-operative bleeding and transfusion requirements were comparable. No thrombotic event occurred in the CPB circuit. CONCLUSION: The current IBW-adjusted regimen of heparin administration may be used efficiently in obese CPB patients, thereby avoiding overdose which cannot be accurately assessed by ACT monitoring alone. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02675647.

Effect of Xenon Anesthesia Compared to Sevoflurane and Total Intravenous Anesthesia for Coronary Artery Bypass Graft Surgery on Postoperative Cardiac Troponin Release: An International, Multicenter, Phase 3, Single-blinded, Randomized Noninferiority Trial.

BACKGROUND: Ischemic myocardial damage accompanying coronary artery bypass graft surgery remains a clinical challenge. We investigated whether xenon anesthesia could limit myocardial damage in coronary artery bypass graft surgery patients, as has been reported for animal ischemia models. METHODS: In 17 university hospitals in France, Germany, Italy, and The Netherlands, low-risk elective, on-pump coronary artery bypass graft surgery patients were randomized to receive xenon, sevoflurane, or propofol-based total intravenous anesthesia for anesthesia maintenance. The primary outcome was the cardiac troponin I concentration in the blood 24 h postsurgery. The noninferiority margin for the mean difference in cardiac troponin I release between the xenon and sevoflurane groups was less than 0.15 ng/ml. Secondary outcomes were the safety and feasibility of xenon anesthesia. RESULTS: The first patient included at each center received xenon anesthesia for practical reasons. For all other patients, anesthesia maintenance was randomized (intention-to-treat: n = 492; per-protocol/without major protocol deviation: n = 446). Median 24-h postoperative cardiac troponin I concentrations (ng/ml [interquartile range]) were 1.14 [0.76 to 2.10] with xenon, 1.30 [0.78 to 2.67] with sevoflurane, and 1.48 [0.94 to 2.78] with total intravenous anesthesia [per-protocol]). The mean difference in cardiac troponin I release between xenon and sevoflurane was -0.09 ng/ml (95% CI, -0.30 to 0.11; per-protocol: P = 0.02). Postoperative cardiac troponin I release was significantly less with xenon than with total intravenous anesthesia (intention-to-treat: P = 0.05; per-protocol: P = 0.02). Perioperative variables and postoperative outcomes were comparable across all groups, with no safety concerns. CONCLUSIONS: In postoperative cardiac troponin I release, xenon was noninferior to sevoflurane in low-risk, on-pump coronary artery bypass graft surgery patients. Only with xenon was cardiac troponin I release less than with total intravenous anesthesia. Xenon anesthesia appeared safe and feasible.

Effect of Levosimendan on Low Cardiac Output Syndrome in Patients With Low Ejection Fraction Undergoing Coronary Artery Bypass Grafting With Cardiopulmonary Bypass: The LICORN Randomized Clinical Trial.

Importance: Low cardiac output syndrome after cardiac surgery is associated with high morbidity and mortality in patients with impaired left ventricular function. Objective: To assess the ability of preoperative levosimendan to prevent postoperative low cardiac output syndrome. Design, Setting, and Participants: Randomized, double-blind, placebo-controlled trial conducted in 13 French cardiac surgical centers. Patients with a left ventricular ejection fraction less than or equal to 40% and scheduled for isolated or combined coronary artery bypass grafting with cardiopulmonary bypass were enrolled from June 2013 until May 2015 and followed during 6 months (last follow-up, November 30, 2015). Interventions: Patients were assigned to a 24-hour infusion of levosimendan 0.1 µg/kg/min (n = 167) or placebo (n = 168) initiated after anesthetic induction. Main Outcomes and Measures: Composite end point reflecting low cardiac output syndrome with need for a catecholamine infusion 48 hours after study drug initiation, need for a left ventricular mechanical assist device or failure to wean from it at 96 hours after study drug initiation when the device was inserted preoperatively, or need for renal replacement therapy at any time postoperatively. It was hypothesized that levosimendan would reduce the incidence of this composite end point by 15% in comparison with placebo. Results: Among 336 randomized patients (mean age, 68 years; 16% women), 333 completed the trial. The primary end point occurred in 87 patients (52%) in the levosimendan group and 101 patients (61%) in the placebo group (absolute risk difference taking into account center effect, -7% [95% CI, -17% to 3%]; P = .15). Predefined subgroup analyses found no interaction with ejection fraction less than 30%, type of surgery, and preoperative use of ß-blockers, intra-aortic balloon pump, or catecholamines. The prevalence of hypotension (57% vs 48%), atrial fibrillation (50% vs 40%), and other adverse events did not significantly differ between levosimendan and placebo. Conclusions and Relevance: Among patients with low ejection fraction who were undergoing coronary artery bypass grafting with cardiopulmonary bypass, levosimendan compared with placebo did not result in a significant difference in the composite end point of prolonged catecholamine infusion, use of left ventricular mechanical assist device, or renal replacement therapy. These findings do not support the use of levosimendan for this indication. Trial Registration: EudraCT Number: 2012-000232-25; clinicaltrials.gov Identifier: NCT02184819.

Identifying optimal heparin management during cardiopulmonary bypass in obese patients: A prospective observational comparative study.

BACKGROUND: The heparin regimen providing anticoagulation during cardiopulmonary bypass (CPB) is usually adapted to total body weight (TBW), but may be inaccurate in obese patients in whom TBW exceeds their ideal body weight. OBJECTIVES: The objective is to compare the effects of heparin injection based on TBW on haemostatic parameters between obese and nonobese patients during cardiac surgery and to calculate the optimal heparin regimen. DESIGN: Prospective comparative study. SETTING: University hospital. PATIENTS: Two groups of 50 patients (BMI≥ or <30 kg m) were included in the study over a 9-month period in 2013. The study started on 27 February 2013. INTERVENTIONS: An unfractionated heparin (UFH) bolus of 300 IU kg TBW was injected before initiation of CPB followed by additional doses (50 to 100 IU kg) to maintain a target activated coagulation time (ACT) of at least 400 s. MAIN OUTCOME MEASURES: ACT and plasma heparin concentration were measured at different time points after initiation of, and weaning from CPB. RESULTS: Obese patients received higher initial and total doses of heparin (P < 0.0001). Plasma heparin concentrations were significantly higher in obese patients at each time point (P < 0.001) and reached very high values after the initial bolus (5.90 vs. 4.48 IU ml, P < 0.0001). The relationship between plasma heparin concentration and ACT after the initial bolus was not linear and followed an asymptotic regression curve. Haemoglobin concentration decreased intraoperatively to a greater extent in the obese group (P < 0.001). No significant differences in postoperative bleeding or global transfusion requirements were observed. CONCLUSION: The standard heparin regimen based on TBW in obese patients during CPB results in excessive plasma heparin concentrations and a significant intraoperative decrease in haemoglobin concentration. ACT monitoring was not accurate in identifying this excess dosage. An initial bolus of 340 IU kg ideal body weight would achieve a heparin concentration of 4.5 IU ml, similar to that observed in nonobese patients. Further investigations are warranted to confirm this heparin regimen.

Optimization of cerebral oxygenation based on regional cerebral oxygen saturation monitoring during carotid endarterectomy: a Phase III multicenter, double-blind randomized controlled trial.

BACKGROUND: Whether the optimization of cerebral oxygenation based on regional cerebral oxygen saturation (rSO2) monitoring reduces the occurrence of cerebral ischemic lesions is unknown. METHODS: This multicenter, randomized, controlled trial recruited adults admitted for scheduled carotid endarterectomy. Patients were randomized between the standard of care or optimization of cerebral oxygenation based on rSO2 monitoring using near-infrared spectroscopy. In the intervention group, in case of a decrease in rSO2 in the intervention, the following treatments were sequentially recommended: (1) increasing oxygenotherapy, (2) reducing the tidal volume, (3) legs up-raising, (4) performing a fluid challenge and (5) initiating vasopressor support. The primary endpoint was the number of new cerebral ischemic lesions detected using magnetic resonance imaging pre- and postoperatively. Secondary endpoints included new neurological deficits and mortality on day 120 after surgery. RESULTS: Among the 879 patients who were randomized, 665 (75.7%) were men. There was no statistically significant difference between groups for the mean number of new cerebral ischemic lesions per patient up to 3 days after surgery: 0.35 (±1.05) in the standard group vs. 0.58 (±2.83), in the NIRS group; mean difference, 0.23 [95% CI, -0.06 to 0.52]; estimate, 0.22 [95% CI, -0.06 to 0.50]. New neurological deficits up to day 120 after hospital discharge were not different between the groups: 15 (3,39%) in the standard group vs. 42 (5,49%) in the NIRS group; absolute difference, 2,10 [95% CI, -0,62 to 4,82]. There was no significant difference between groups for the median [IQR] hospital length of stay: 4.0 [4.0-6.0] in the standard group vs. 5.0 [4.0-6.0] in the NIRS group; mean difference, -0.11 [95% CI, -0.65 to 0.44]. The mortality rate on day 120 was not different between the standard group (0.68%) vs. the NIRS group (0.92%); absolute difference = 0.24% [95% CI, -0.94 to 1.41]. CONCLUSIONS: Among patients undergoing carotid endarterectomy, optimization of cerebral oxygenation based on rSO2 did not reduce the occurrence of cerebral ischemic lesions postoperatively compared with controlled hypertensive therapy. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01415648.

Impact of a phosphorylcholine-coated cardiac bypass circuit on blood loss and platelet function: a prospective, randomized study.

Platelet dysfunction due to cardiopulmonary bypass (CPB) surgery increases the risk of bleeding. This study analyzed the effect of a phosphorylcholine (PC)-coated CPB circuit on blood loss, transfusion needs, and platelet function. We performed a prospective, randomized study at Strasbourg University Hospital, which included 40 adults undergoing coronary artery bypass graft surgery (CABG) (n = 20) or mitral valve repair (n = 20) using CPB. Patients were randomized either to PC-coated CPB or uncoated CPB (10 CABG patients and 10 mitral valve repair patients in each group). Blood loss and transfusion needs were evaluated intra- and postoperatively. Markers of platelet activation and thrombin generation were measured at anesthesia induction, at the beginning and end of CPB, on skin closure, and on days 0, 1, and 5. Comparisons were made by Student's t test or covariance analysis (significance threshold p < or = .05). Blood loss was significantly lower in the PC group during the first 6 postoperative hours (171 +/- 102 vs. 285 +/- 193 mL, p = .024), at the threshold of significance from 6-24 hours (p = .052), and similar in both groups after 24 hours. During CPB, platelet count decreased by 48% in both groups. There was no difference in markers of platelet activation, thrombin generation, or transfusion needs between the two groups. Norepinephrine use was more frequent in the control group (63% vs. 33%) but not significantly. PC-coating of the CPB surface reduced early postoperative bleeding, especially in CABG patients, but had no significant effect on platelet function because of large interindividual variations that prevented the establishment of a causal relationship.

Intramural atrial hematoma complicating transesophageal echocardiography during cardiac arrest.

BACKGROUND: Adequate strategies using either transthoracic (TTE) or transesophageal (TEE) echocardiography in patients receiving cardiopulmonary resuscitation (CPR) is an ongoing area of research. OBJECTIVES: As transthoracic point-of-care ultrasound (POCUS) during cardiac arrest resuscitation might result in an increased duration of interruptions in the delivery of chest compressions; the use of TEE has been proposed as an alternative. METHODS: No technical complications of either TTE nor TEE are so far being reported in the literature. RESULTS: We report the case of a left intramural atrial hematoma complicating TEE procedure during cardiac arrest. This highlights a unique and to our knowledge, first-in-man, described complicating TEE procedure during CPR. CONCLUSIONS: Further research on the safety of transesophageal echo during CRP is mandatory and the question about any potential harm of particular interest.

Twenty-seven-year experience with composite valve graft replacement of the aortic root.

BACKGROUND AND AIM OF THE STUDY: The study aim was to assess early and late outcome in patients undergoing composite valve graft replacement (CVGR) of the aortic root by means of the Bentall procedure, and to identify predictors of early and late death associated with this surgical approach. METHODS: Between August 1975 and July 2002, 162 consecutive patients underwent a Bentall procedure for CVGR. Demographic, treatment and clinical outcome data from these patients were gathered, reviewed, and analyzed. Potential predictors of early and late mortality were analyzed. RESULTS: The study population was predominantly male (n = 132; 81.5%) and middle-aged (mean age 51.3 +/- 15.8 years; range: 10-79 years). The main indications for surgery were annuloaortic ectasia (n = 75; 46.3%), aortic dissection (n = 44; 27.2%) and Marfan syndrome (n = 34; 21%). Reoperation was required in 37 cases (22.8%). The mean follow up was 74 months. Early (in-hospital) mortality was 1.9% (n = 3). The only independent determinant of early mortality was cardiopulmonary bypass time (p = 0.025). Late mortality was 27.7% (n = 44). On multivariate analysis, the only independent risk factors for late mortality were age >60 years (p = 0.044) and left ventricular ejection fraction <50% (p = 0.037). Actuarial survival rates were 92.9%, 77%, 56.2%, and 47.1% at one, five, 10, and 15 years, respectively. Rates of freedom from reoperation on the aortic root and ascending aorta were 90.6% and 72.5% at five and 15 years, respectively. No false aneurysms were observed at any coronary reimplantation sites. CONCLUSION: In this series, the Bentall procedure was associated with low operative mortality and good early and late results. This suggests that the procedure may be considered as a reference to other operations on the aortic root, at least in adult patients.

Increased Extravascular Lung Water and Plasma Biomarkers of Acute Lung Injury Precede Oxygenation Impairment in Primary Graft Dysfunction After Lung Transplantation.

BACKGROUND: After lung transplantation (LT), early prediction of grade 3 pulmonary graft dysfunction (PGD) remains a research gap for clinicians. We hypothesized that it could be improved using extravascular lung water (EVLWi) and plasma biomarkers of acute lung injury. METHODS: After institutional review board approval and informed consent, consecutive LT recipients were included. Transpulmonary thermodilution-based EVLWi, plasma concentrations of epithelial (soluble receptor for advanced glycation endproducts [sRAGE]) and endothelial biomarkers (soluble intercellular adhesion molecule-1 and endocan [full-length and cleaved p14 fragment]) were obtained before and after LT (0 [H0], 6, 12, 24, 48 and 72 hours after pulmonary artery unclamping). Grade 3 PGD was defined according to the International Society for Lung and Heart Transplantation definition, combining arterial oxygen partial pressure (PaO2)/inspired fraction of oxygen (FiO2) ratio and chest X-rays. Association of clinical risk factors, EVLWi and biomarkers with grade 3 PGD was analyzed under the Bayesian paradigm, using logistic model and areas under the receiver operating characteristic curves (AUCs). RESULTS: In 47 LT recipients, 10 developed grade 3 PGD, which was obvious at H6 in 8 cases. Clinical risk factors, soluble intercellular adhesion molecule-1 and endocan (both forms) were not associated with grade 3 PGD. Significant predictors of grade 3 PGD included (1) EVLWi (optimal cutoff, 13.7 mL/kg; AUC, 0.74; 95% confidence interval [CI], 0.48-0.99), (2) PaO2/FiO2 ratio (optimal cutoff, 236; AUC, 0.68; 95% CI, 0.52-0.84), and (3) sRAGE (optimal cutoff, 11 760 pg/mL; AUC, 0.66; 95% CI, 0.41-0.91) measured at H0. CONCLUSIONS: Immediate postreperfusion increases in EVLWi and sRAGE along with impaired PaO2/FiO2 ratios were early predictors of grade 3 PGD at or beyond 6 hours and may trigger early therapeutic interventions.

Exercising with a denervated heart after cardiac transplantation.

Heart transplantation (HTR) is now an accepted life-extending procedure for those dying of intractable heart failure (CHF). HTR patients expect a high quality of life which implies a reasonable exercise capacity. Nevertheless HTR present unique exercise challenges with both central and peripheral factors of limitation that result in peak oxygen uptakes of 60-70% of age-matched normal subjects. Among central factors persistent chronotropic incompetence questions the occurrence and role of the graft reinnervation. Among peripheral factors the energetic impairement of the skeletal muscle seem to result more from microvascular abnormalities than from an actual deficit in oxidative capacity, questioning the mechanism of recovery from the CHF peripheral myopathy and the role of immunosuppressive drugs. Endurance and resistance training programs may reverse at least in part most but not all of these abnormalities. Training permits patients to engage in sports and even to participate in competitive events that are rewarding to them but also to the community because it promotes organ donation and confidence in medical achievements. Mechanisms of exercise impairments and improvements resulting from training are discussed in the perspective of current literature. Areas of future research and recommendations for the practice of sports after HTR are suggested.

Conflicts versus analytical redundancy relations: a comparative analysis of the model based diagnosis approach from the artificial intelligence and automatic control perspectives.

Two distinct and parallel research communities have been working along the lines of the model-based diagnosis approach: the fault detection and isolation (FDI) community and the diagnostic (DX) community that have evolved in the fields of automatic control and artificial intelligence, respectively. This paper clarifies and links the concepts and assumptions that underlie the FDI analytical redundancy approach and the DX consistency-based logical approach. A formal framework is proposed in order to compare the two approaches and the theoretical proof of their equivalence together with the necessary and sufficient conditions is provided.