Thrombin generation during cardiopulmonary bypass: the possible role of retransfusion of blood aspirated from the surgical field

BACKGROUND: In spite of using heparin-coated extracorporeal circuits, cardiopulmonary bypass (CPB) is still associated with an extensive thrombin generation, which is only partially suppressed by the use of high dosages of heparin. Recent studies have focused on the origins of this thrombotic stimulus and the possible role of retransfused suctioned blood from the thoracic cavities on the activation of the extrinsic coagulation pathway. The present study was designed to find during CPB an association between retransfusion of suctioned blood from the pericardium and pleural space, containing activated factor VIIa and systemic thrombin generation. METHODS: Blood samples taken from 12 consenting patients who had elective cardiac surgery were assayed for plasma factor VIIa, prothrombin fragment 1+2 (F(1+2)), and thrombin-antithrombin (TAT) concentrations. Blood aspirated from the pericardium and pleural space was collected separately, assayed for F(1+2), TAT, and factor VIIa and retransfused to the patient after the aorta occlusion. RESULTS: After systemic heparinization and during CPB thrombin generation was minimal, as indicated by the lower than base line plasma levels of F(1+2), and TAT after correction for hemodilution. In contrast, blood aspirated from the thoracic cavities had significantly higher levels of factor VIIa, F(1+2), and TAT compared to the simultaneous samples from the blood circulation (P < 0.05). Furthermore, after retransfusion of the suctioned blood (range, 200–1600 mL) circulating levels of F(1+2), and TAT rose significantly from 1.6 to 2.9 nmol/L (P = 0.002) and from 5.1 to 37.5 μg/L (P = 0.01), respectively. The increase in both F(1+2), and TAT levels correlated significantly with the amount of retransfused suctioned blood (r = 0.68, P = 0.021 and r = 0.90, P = 0.001, respectively). However, the circulating factor VIIa levels did not correlate with TAT and F(1+2 )levels. CONCLUSIONS: These data suggest that blood aspirated from the thoracic cavities during CPB is highly thrombogenic. Retransfusion of this blood may, therefore, promote further systemic thrombin generation during CPB

Quantification of recirculation as an adjuvant to transthoracic echocardiography for optimization of dual-lumen extracorporeal life support

Proper cannula positioning in single site veno-venous extracorporeal life support (vv-ELS) is cumbersome and necessitates image guidance to obtain a safe and stable position within the heart and the caval veins. Importantly, image-guided cannula positioning alone is not sufficient, as possible recirculation cannot be quantified. We present an ultrasound dilution technique allowing quantification of recirculation for optimizing vv-ELS. We suggest quantification of recirculation in addition to image guidance to provide optimal vv-ELS

Quantitative assessment of cardiac load-responsiveness during extracorporeal life support: case and rationale

We describe a case of a patient assisted by extracorporeal life support, in which we obtained the dynamic filling index, a measure for venous volume during extracorporeal life support, and used this index to assess cardiac load-responsiveness during acute reloading. While reloading, the obtained findings on cardiac pump function by the dynamic filling index were supported by trans-esophageal echocardiography and standard pressure measurement. This suggests that the dynamic filling index can be used to assess cardiac load-responsiveness during extracorporeal life support

Realisation of the guidelines for faculty-internal exams at the Department of General Medicine at the University of Munich

Graded exams are prerequisites for the admission to the medical state examination. Accordingly the exams must be of good quality in order to allow benchmarking with the faculty and between different universities. Criteria for good quality need to be considered - namely objectivity, validity and reliability. The guidelines for the processing of exams published by the GMA are supposed to help maintaining those criteria. In 2008 the Department of General Medicine at the University of Munich fulfils only 14 of 18 items. A review process, appropriate training of the staff and the introduction of the IMSm software were the main changes that helped to improve the ‘GMA-score’ to 30 fulfilled items. We see the introduction of the IMSm system as our biggest challenge ahead. IMSm helps to streamline the necessary workflow and improves their quality (e.g. by the detection of cueing, item analysis). Overall, we evaluate the steps to improve the exam process as very positive. We plan to engage co-workers outside the department to assist in the various review processes in the future. Furthermore we think it might be of value to get into contact with other departments and faculties to benefit from each other’s question pools

Extracorporeal Life Support in Adult Patients A Global Perspective of the Last Decade

Extracorporeal life support (ECLS) is an external medical device to treat critically ill patients with cardiovascular and respiratory failure. In a nutshell, ECLS is only a "bridging" mechanism that provides life support while the heart and/or the lungs is recovering either by therapeutic medical interventions, transplantation, or spontaneously. Extracorporeal life support has been developed since 1950s, and many studies were conducted to improve ECLS techniques, but unfortunately, the survival rate was not improved. Because of Dr Bartlett's success in using ECLS to treat neonates with severe respiratory distress in 1975, ECLS is made as a standard lifesaving therapy for neonates with severe respiratory distress. However, its use for adult patients remains debatable. The objectives of this study are to outline and provide a general overview of the use of ECLS especially for adult patients for the past 10 years and to elaborate on the challenges encountered by each stakeholder involved in ECLS. The data used for this study were extracted from the ELSO Registry Report of January 2018. Results of this study revealed that the number of ECLS centers and the use of ECLS are increasing over the year for the past decade. There was also a shift of the patient's age category from neonatal to adult patients. However, the survival rates for adult patients are relatively low especially for cardiac and extracorporeal cardiopulmonary resuscitation cases. To date, the complications are still the major challenge of ECLS. Other challenges encountered by the stakeholders in ECLS are the limited amount of well-trained and experienced ECLS teams and centers, the limited government expenditure on health, and the lack of improvement and development of ECLS techniques and devices. Further studies are needed to evaluate the value of ECLS for adult patients.</p

Non-Invasive Tissue Oximetry-An Integral Puzzle Piece

Non-invasive tissue oximetry is a monitoring method for continuous assessment of tissue oxygenation, which may aid in detection of hemodynamic instability and otherwise unnoticed hypoxia. Numerous studies focused on using non-invasive tissue oximetry intraoperatively, proposing its predictive value in relation to clinical outcome. Tissue oximetry may be part of standard monitoring practice for brain monitoring during cardiac surgery in many clinical centers; however, the monitoring method can be deployed in numerous clinical settings. This succinct overview aims to determine the role of non-invasive tissue oximetry in current clinical practice

Non-Invasive Tissue Oximetry-An Integral Puzzle Piece

Non-invasive tissue oximetry is a monitoring method for continuous assessment of tissue oxygenation, which may aid in detection of hemodynamic instability and otherwise unnoticed hypoxia. Numerous studies focused on using non-invasive tissue oximetry intraoperatively, proposing its predictive value in relation to clinical outcome. Tissue oximetry may be part of standard monitoring practice for brain monitoring during cardiac surgery in many clinical centers; however, the monitoring method can be deployed in numerous clinical settings. This succinct overview aims to determine the role of non-invasive tissue oximetry in current clinical practice