Evaluation of a New Sonoclot Device for Heparin Management in Cardiac Surgery.

BACKGROUND: Sonoclot is used to measure kaolin-based activated clotting time (kACT) for heparin management. Apart from measuring kACT, the device assesses the patient's coagulation status by glass bead-activated tests (gbACTs; measuring also clot rate [CR] and platelet function [PF]). Recently, a new version of the Sonoclot has been released, and the redesign may result in performance changes. The aim of this study was to evaluate and compare the performance of the new (S2) and the previous (S1) Sonoclot. METHODS: The S1 was used in the routine management of 30 patients undergoing elective cardiac surgery. Blood samples were taken at baseline (T1), after heparin administration (200 U/kg, 100 U/kg; T2 and T3), during cardiopulmonary bypass (T4), after protamine infusion (T5), and before intensive care unit transfer (T6). Kaolin-based activated clotting time and gbACTs were measured in duplicate by both the old and the new device and performance compared by Bland-Altman analysis and percentage error calculation. RESULTS: A total of 300 kACT and 180 gbACTs were available. Bland-Altman analysis for kACT revealed that S2 consistently reported results in shorter time compared to S1 (overall = -14.7%). Comparing S2 and S1, the glass bead-activated tests showed mean percentage differences of -18.9% (gbACTs), +37.4% (CR), and -3.7% (PF). CONCLUSION: Since clotting is faster in the new S2 compared to S1, shorter clotting times have to be considered in clinical practice. The use of S2 kACT in heparin management will result in higher heparin and protamine dosing unless heparin kACT target values are adjusted to correct for the differences in results between S1 and S2.

Extracorporeal Membrane Oxygenation in Miliary Tuberculosis and AIDS: A Case Report.

Background The aim of this study is to present the success of a multidisciplinary approach in a patient with a rare triad of disease. Case Description A 33-year-old patient with newly diagnosed human immunodeficiency virus infection presented with miliary tuberculosis, consecutive adult respiratory distress syndrome, and multiple-organ failure. An interdisciplinary, time-limited approach combining extracorporeal membrane oxygenation, intensive care therapy, hemodiafiltration, tuberculostatic therapy, steroids, and antiretroviral therapy led to survival despite a low probability at presentation. Conclusion Even though the use of such extensive and expensive treatment can be questioned, this example encourages an aggressive approach in a young patient, even in situations of multiple diagnosis of individually limited prognosis.

High risk of intraoperative awareness during cardiopulmonary bypass with isoflurane administration via diffusion membrane oxygenators.

In cardiac surgery with the aid of extracorporeal circulation (ECC), inhalation anaesthetics can be administered via the oxygenator. Until the recent advent of a new type of diffusion membrane oxygenator, we routinely added the inhalation agent, isoflurane, to the gas flow of a microporous capillary membrane-type oxygenator. Applying this procedure to the diffusion-type oxygenators, the depth of anaesthesia appeared to be affected, which manifested itself through unusually high intraoperative perfusion pressures. This observation led to a prospective randomized study comprising 60 patients and two models of a microporous capillary membrane oxygenator, as well as two models of a diffusion membrane oxygenator. Simultaneous isoflurane concentration measurements at both the gas inlet and outlet ports of the oxygenators showed that, whereas in the microporous capillary-type oxygenators the isoflurane administered was reduced by about 50% during the passage of gas through the device, there was only a minimal transfer of isoflurane in the diffusion-type membrane oxygenators.