Point-of-care testing in the cardiovascular operating theatre

Point-of-care testing (POCT) remains under scrutiny by healthcare professionals because of its ill-tried, young history. POCT methods are being developed by a few major equipment companies based on rapid progress in informatics and nanotechnology. Issues as POCT quality control, comparability with standard laboratory procedures, standardisation, traceability and round robin testing are being left to hospitals. As a result, the clinical and operational benefits of POCT were first evident for patients on the operating table. For the management of cardiovascular surgery patients, POCT technology is an indispensable aid. Improvement of the technology has meant that clinical laboratory pathologists now recognise the need for POCT beyond their high-throughput areas. Clin Chem Lab Med 2006;44:1060-

Minimal versus conventional cardiopulmonary bypass: assessment of intraoperative myocardial damage in coronary bypass surgery

Objective: Minimal extracorporeal circulation (mini-ECC) is a new technology, consisting of a centrifugal pump, an oxygenator, and a modified suction system. The main advantage of mini-ECC is the reduction of tubing length (reduction of the priming volume). Additional beneficial effects are a decrease of coagulation cascade and a reduction of blood transfusion in patients undergoing coronary artery bypass grafting (CABG) surgery. We compared the intraoperative and early postoperative myocardial damage and outcome of patients who underwent CABG surgery with conventional cardiopulmonary bypass (CPB) or mini-ECC. Methods: One hundred and thirty-six consecutive patients who underwent isolated CABG surgery at our institution were prospectively studied. Fifty-four patients (39.7%) were operated with mini-ECC. Patient characteristics were similar in both groups. The most interesting intraoperative details as well as in-hospital outcome were assessed. Results: There was no difference in mortality between the two groups. Cross-clamping time was similar in both groups (p = 0.07). Defibrillation was required in one patient in the mini-ECC group (1.9%) and in 38 patients (46.3%) in the CPB group (p < 0.001). In the mini-ECC group, the requirement of inotropic support and incidence of atrial fibrillation was significantly lower than in the CPB group. Postoperative creatine kinase isoenzyme MB (CK-MB) and cardiac Troponin I (cTnI) were significantly lower in the mini-ECC group (p < 0.05). Duration of ventilation, length of stay in the intensive care unit and total hospitalization time were significantly shorter in patients operated with mini-ECC (p < 0.05). Conclusion: Mini-ECC is a safe procedure and is followed by a diminished release of CK-MB and cTnI than after CPB. Postoperative recovery is accelerated following mini-ECC and there is a significantly lower incidence of postoperative atrial fibrillatio

Autotransfusion system or integrated automatic suction device in minimized extracorporeal circulation: influence on coagulation and inflammatory response

Objective: To measure surrogate markers of coagulation activation as well as of the systemic inflammatory response in patients undergoing primary elective coronary artery bypass grafting (CABG) using either the so-called Smart suction device or a continuous autotransfusion system (C.A.T.S.®). Methods: Fifty-eight patients being operated with a miniaturized circuit (minimal extracorporeal circuit, MECC) were prospectively randomized to using a so-called Smart suction device or a routine continuous autotransfusion system (C.A.T.S.®) for collection of mediastinal shed blood. The coagulation response was measured by thrombin-antithrombin complex (TAT) and D-dimer. The inflammatory response was measured by Interleukin 6 (IL-6) and complement factor 3a (C3a) at three different time points, before surgery, 2h after surgery, as well as 18h after surgery. Results: No serious adverse cardiovascular event was observed. Serum levels of TAT significantly differed between both groups 2h after surgery (Smart suction 16.12±13.51μgl−1 vs C.A.T.S® 9.83±7.81μgl−1, p=0.040) and returned to baseline values after 18h in both groups. Serum levels of D-dimer showed a corresponding pattern with a peak 2h after surgery (Smart suction 1115±1231ngml−1 vs C.A.T.S.® 507±604ngml−1, p=0.025). IL-6 levels also significantly differed between both groups 2h after surgery (Smart suction 186±306pgml−1 vs C.A.T.S.® 82±71pgml−1, p=0.072). No significant changes in serum levels of C3a over time could be observed. Conclusions: Despite no differences in the clinical course of patients with either Smart suction or C.A.T.S.® being observed, surrogate markers of coagulation and inflammation seem to be less pronounced in patients where cardiotomy blood is not being directly reinfused. As such, C.A.T.S.® should be preferred in routine CABG, as long as no extensive volume substitution is anticipate

Multi-phase post-mortem CT angiography: development of a standardized protocol

The objective of this work was to develop an easily applicable technique and a standardized protocol for high-quality post-mortem angiography. This protocol should (1) increase the radiological interpretation by decreasing artifacts due to the perfusion and by reaching a complete filling of the vascular system and (2) ease and standardize the execution of the examination. To this aim, 45 human corpses were investigated by post-mortem computed tomography (CT) angiography using different perfusion protocols, a modified heart-lung machine and a new contrast agent mixture, specifically developed for post-mortem investigations. The quality of the CT angiographies was evaluated radiologically by observing the filling of the vascular system and assessing the interpretability of the resulting images and by comparing radiological diagnoses to conventional autopsy conclusions. Post-mortem angiography yielded satisfactory results provided that the volumes of the injected contrast agent mixture were high enough to completely fill the vascular system. In order to avoid artifacts due to the post-mortem perfusion, a minimum of three angiographic phases and one native scan had to be performed. These findings were taken into account to develop a protocol for quality post-mortem CT angiography that minimizes the risk of radiological misinterpretation. The proposed protocol is easy applicable in a standardized way and yields high-quality radiologically interpretable visualization of the vascular system in post-mortem investigation

Point-of-care testing in the cardiovascular operating theatre

Point-of-care testing (POCT) remains under scrutiny by healthcare professionals because of its ill-tried, young history. POCT methods are being developed by a few major equipment companies based on rapid progress in informatics and nanotechnology. Issues as POCT quality control, comparability with standard laboratory procedures, standardisation, traceability and round robin testing are being left to hospitals. As a result, the clinical and operational benefits of POCT were first evident for patients on the operating table. For the management of cardiovascular surgery patients, POCT technology is an indispensable aid. Improvement of the technology has meant that clinical laboratory pathologists now recognise the need for POCT beyond their high-throughput areas

Minimal versus conventional cardiopulmonary bypass: assessment of intraoperative myocardial damage in coronary bypass surgery

Objective: Minimal extracorporeal circulation (mini-ECC) is a new technology, consisting of a centrifugal pump, an oxygenator, and a modified suction system. The main advantage of mini-ECC is the reduction of tubing length (reduction of the priming volume). Additional beneficial effects are a decrease of coagulation cascade and a reduction of blood transfusion in patients undergoing coronary artery bypass grafting (CABG) surgery. We compared the intraoperative and early postoperative myocardial damage and outcome of patients who underwent CABG surgery with conventional cardiopulmonary bypass (CPB) or mini-ECC. Methods: One hundred and thirty-six consecutive patients who underwent isolated CABG surgery at our institution were prospectively studied. Fifty-four patients (39.7%) were operated with mini-ECC. Patient characteristics were similar in both groups. The most interesting intraoperative details as well as in-hospital outcome were assessed. Results: There was no difference in mortality between the two groups. Cross-clamping time was similar in both groups (p = 0.07). Defibrillation was required in one patient in the mini-ECC group (1.9%) and in 38 patients (46.3%) in the CPB group (p < 0.001). In the mini-ECC group, the requirement of inotropic support and incidence of atrial fibrillation was significantly lower than in the CPB group. Postoperative creatine kinase isoenzyme MB (CK-MB) and cardiac Troponin I (cTnI) were significantly lower in the mini-ECC group (p < 0.05). Duration of ventilation, length of stay in the intensive care unit and total hospitalization time were significantly shorter in patients operated with mini-ECC (p < 0.05). Conclusion: Mini-ECC is a safe procedure and is followed by a diminished release of CK-MB and cTnI than after CPB. Postoperative recovery is accelerated following mini-ECC and there is a significantly lower incidence of postoperative atrial fibrillation