BACKGROUND: Cardiac surgery with cardiopulmonary bypass is associated with important changes in the microcirculation, usually attributed to endothelial dysfunction. Another common finding of cardiac surgery is postoperative thrombocytopenia and platelet loss of function. OBJECTIVE: To investigate the association between microvascular flow pattern and postoperative changes in platelet count and function in cardiac surgery patients. METHODS: Twelve adult cardiac surgery patients received microvascular circulation (sidestream darkfield sublingual mucosa analysis) and platelet count and function (multiple electrode aggregometry ADPtest and TRAPtest) assessment before and after cardiopulmonary bypass. RESULTS: After cardiopulmonary bypass, sublingual microcirculation showed a significantly ( P = 0.001) decreased microvascular flow index and increased heterogeneity index ( P = 0.006). Platelet function significantly decrease after cardiopulmonary bypass both at ADPtest ( P = 0.011) and TRAPtest ( P = 0.002). Preoperative patterns of poor microvascular perfusion (low perfused vessels density and total vessels density) were significantly associated with lower values of post-cardiopulmonary bypass platelet function (ADPtest, P = 0.009, TRAPtest, P = 0.031) and count ( P = 0.048). CONCLUSIONS: A preoperative disturbance of the microcirculation is associated with a greater postoperative platelet dysfunction. Endothelial damage, chemical and mechanical stimuli are the possible link between the two patterns.

Background: Presently, a number of specific observations have been performed on microcirculatory function in a coronavirus disease-19 (COVID-19) setting. We hypothesized that, in the critically ill, endothelial dysfunction secondary to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and the subsequent inflammation and coagulopathy may lead to microcirculatory alterations, further exacerbated by the hypoxemic state. A dysfunctional microcirculation may represent the hidden motor underlying the development of COVID-19’s clinical manifestations. Methods: A single center, prospective, observational study. We analyzed bedside sublingual microcirculation in twenty-four consecutive COVID-19-associated acute respiratory distress syndrome (ARDS) patients mechanically ventilated in an Intensive Care Unit (ICU), together with macro-hemodynamics, clinical parameters, echocardiography, and laboratory data at a single time-point after ICU admission. All participants were recruited between March and May 2020. Results: The microcirculatory pattern was characterized by increased values of total vessel density and perfused vessel density, a reduced value of proportion of perfused vessels and microvascular flow index, and high values of heterogeneity index. The duration of mechanical ventilation before microcirculation assessment was inversely associated with the proportion of perfused vessels (p = 0.023). Within the macro-hemodynamic parameters, the right ventricle end-diastolic diameter was inversely associated with proportion of perfused vessels and microvascular flow index (p = 0.039 and 0.014, respectively) and directly associated with the heterogeneity index (p = 0.033). Conclusions: In COVID-19-associated ARDS patients, the microcirculation showed impaired quality of flow parameters coupled with a high vessel density.

Extracorporeal Membrane Oxygenation (ECMO) is an advanced life support modality for patients with respiratory or cardiac failure refractory to standard therapy

The recently released EACTS/EACTA/EBCP guidelines on cardiopulmonary bypass (CPB) in adult cardiac surgery

Background/Objectives: A low level of soluble coagulation factors after cardiac surgery may cause excessive bleeding and trigger clinical correction using prothrombin complex concentrate (PCC). According to the current guidelines, the trigger values for PCC administration are not defined. In the published algorithms, when driven by ROTEM^®, the triggers vary from 80 s to >100 s of coagulation time (CT) during an EXTEM test. Two randomized controlled trials on fibrinogen (FC) supplementation after cardiac surgery previously pointed out that the patients receiving FC supplementation had a significant decrease in their EXTEM CT. This study investigates the hypothesis that after increasing the availability of a substrate (fibrinogen), thrombin generation induces fibrin network formation faster, and that, before considering PCC administration, the normalization of fibrinogen levels should be sought. Methods: A retrospective study based on a post-hoc analysis of the data collected in two previous RCTs involving 85 patients, all of whom received FC supplementation. Results: The results of this post-hoc analysis demonstrate that there is a significant negative association between FIBTEM maximum clot firmness (MCF) and the EXTEM CTs before and after FC supplementation; FC supplementation decreases the EXTEM CTs both in patients with a low FIBTEM MCF and a normal FIBTEM MCF. After FC supplementation, 45 (53%) of the patients had an EXTEM CT of >80 s, 22 (26%) had an EXTEM CT of >90 s, and 8 (9%) had an EXTEM CT of >100 s. Conclusions: Our study confirms and quantifies the effects of reducing EXTEM CTs through FC supplementation. A stepwise strategy of factors correction with FC supplementation should be used before considering PCC administration as it might reduce the need for PCC.

Background: Infants < 10 kg undergoing cardiac surgery with cardiopulmonary bypass (CPB) may receive either fresh frozen plasma (FFP) or other solutions in the CPB priming volume. The existing comparative studies are controversial. No study addressed the possibility of total avoidance of FFP throughout the whole perioperative course in this patient population. This retrospective, non-inferiority, propensity-matched study investigates an FFP-free strategy compared to an FFP-based strategy. Methods: Among patients <10 kg with available viscoelastic measurements, 18 patients who received a total FFP-free strategy were compared to 27 patients (1:1.5 propensity matching) receiving an FFP-based strategy. The primary endpoint was chest drain blood loss in the first 24 postoperative hours. The level of non-inferiority was settled at a difference of 5 mL/kg. Results: The 24-h chest drain blood loss difference between groups was −7.7 mL (95% confidence interval −20.8 to 5.3) in favor of the FFP-based group, and the non-inferiority hypothesis was rejected. The main difference in coagulation profile was a lower level of fibrinogen concentration and FIBTEM maximum clot firmness in the FFP-free group immediately after protamine, at the admission in the ICU and for 48 postoperative hours. No differences in transfusion of red blood cells or platelet concentrate were observed; patients in the FFP-free group did not receive FFP but required a larger dose of fibrinogen concentrate and prothrombin complex concentrate. Conclusions: An FFP-free strategy in infants < 10 kg operated with CPB is technically feasible but results in an early post-CPB coagulopathy that was not completely compensated with our bleeding management protocol.