IntroductionCoagulation and fibrinolysis remain sparsely addressed with regards to acute respiratory distress syndrome (ARDS). We hypothesized that ARDS development might be associated with changes in plasma coagulation and fibrinolysis. Our aim was to investigate the relationships between ARDS diagnosis and plasma concentrations of tissue factor (TF), tissue plasminogen activator (t-PA), and plasminogen activator inhibitor-1 (PAI-1) in mechanically ventilated patients at increased risk of developing ARDS.Materials and methodsWe performed an ethically approved prospective observational pilot study. Inclusion criteria were patients with PaO2/FiO2 < 300 mmHg admitted to the intensive care unit (ICU) for mechanical ventilation for 24 h, or more, because of one or more disease conditions associated with increased risk of developing ARDS. Exclusion criteria were age below 18 years; cardiac disease. We sampled plasma prospectively and compared patients who developed ARDS with those who did not using descriptive statistics and chi-square analysis of baseline demographical and clinical data. We also analyzed plasma concentrations of TF, t-PA, and PAI-1 at inclusion (T0) and on third (T3) and seventh day (T7) of the ICU stay with non-parametric statistics inclusive their sensitivity and specificity associated with the development of ARDS using receiver operating characteristic curve analysis. Statistical significance: p < 0.05.ResultsOf 24 patients at risk, 6 developed mild ARDS and 4 of each moderate or severe ARDS, respectively, 3 ± 2 (mean ± SD) days after inclusion. Median plasma concentrations of TF and PAI-1 were significantly higher at T7 in patients with ARDS, as compared to non-ARDS. Simultaneously, we found moderate correlations between plasma concentrations of TF and PAI-1, TF and PaO2/FiO2, and positive end-expiratory pressure and TF. TF plasma concentration was associated with ARDS with 71% sensitivity and 100% specificity, a cut off level of 145 pg/ml and AUC 0.78, p = 0.02. PAI-1 displayed 64% sensitivity and 100% specificity with a cut off concentration of 117.5 pg/ml and AUC 0.77, p = 0.02. t-PA did not change significantly during the observation time.ConclusionThis pilot study showed that increased plasma concentrations of TF and PAI-1 might support ARDS diagnoses in mechanically ventilated patients after 7 days in ICU.

BackgroundEnhanced bleeding remains a serious problem after cardiac surgery, and fibrinolysis is often involved. We speculate that lower plasma concentrations of plasminogen activator inhibitor – 1 (PAI-1) preoperatively and tissue plasminogen activator/PAI-1 (t-PA/PAI-1) complex postoperatively might predispose for enhanced fibrinolysis and increased postoperative bleeding.MethodsTotally 88 adult patients (mean age 66 ± 10 years) scheduled for cardiac surgery, were enrolled into a prospective study. Blood samples were collected pre-operatively, on admission to the recovery and at 6 and 24 hours postoperatively. Patients with a surgical bleeding that was diagnosed during reoperation were discarded from the study. The patients were allocated to two groups depending on the 24-hour postoperative chest tube drainage (CTD): Group I > 500ml, Group II ≤ 500ml. Associations between CTD, PAI-1, t-PA/PAI-1 complex and D-dimer were analyzed with SPSS.ResultsNine patients were excluded because of surgical bleeding. Of the 79 remaining patients, 38 were allocated to Group I and 41 to Group II. The CTD volumes correlated with the preoperative plasma levels of PAI-1 (r = − 0.3, P = 0.009). Plasma concentrations of preoperative PAI-1 and postoperative t-PA/PAI-1 complex differed significantly between the groups (P < 0.001 and P = 0.012, respectively). Group I displayed significantly lower plasma concentrations of fibrinogen and higher levels of D-dimer from immediately after the operation and throughout the first 24 hours postoperatively.ConclusionsLower plasma concentrations of PAI-1 preoperatively and t-PA/PAI-1 complex postoperatively leads to higher plasma levels of D-dimer in association with more postoperative bleeding after cardiac surgery.

Introduction: Coagulation assessment is often missing in microvascular surgery. We aimed at evaluating the predictive value of thromboelastometry for free flap thrombosis in microvascular surgery patients. Conclusions:In LS patients with thrombogenic comorbidities, thromboelastometry supports the detection of hypercoagulability and predicts free flap thrombosis risk. In ES patients, postoperative hypercoagulability did not predict free flap thrombosis. Prolonged surgery time should be considered as a risk factor.

Microvascular free flap surgery, has become an important part of reconstructive surgery during the last decades, as it allows closure of various tissue defects and recovery of organs function. Despite surgical progress resulting in high rates of transferred tissue survival, the risk of pedicle vessels thrombosis still remains a significant problem. A total of 108 articles from Pubmed and Science Direct databases published in 2005–2015 were analysed. This review of the literature assessed the influence of patient-dependent risk factors and different perioperative management strategies on development of microvascular free flap thrombosis. Sufficient evidence for risk associated with hypercoagulation, advanced age and certain comorbidities was identified. Presently, rotational thromboelastometry allows early hypercoagulability detection, significantly changing further patient management. Identification of flap thrombosis promoting surgery-related aspects is also essential in preoperative settings. Choice of anaesthesia and postoperative analgesia, administration of different types and amounts of fluids, blood products and vasoactive agents, temperature control are no less important in perioperative anaesthesiological management. More attention should be focused on timely preoperative evaluation of patient-dependent risk factors, which can influence anaesthesiological and surgical tactics during and after microvascular free flap surgery. Perioperative anaesthesiological management strategy continues to be controversial and therefore it should be performed based on thrombotic risk assessment and patient individual needs, thus improving flap survival rates and surgical outcome.