Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Dear Editor,
Plasma free haemoglobin is the gold standard for monitoring for intravascular haemolysis in extracorporeal membrane oxygenation (ECMO), and its use is recommended by the Extracorporeal Life Support Organisation [1]. Elevated plasma free haemoglobin is an independent predictor of mortality during ECMO [2]. Severe haemolysis may herald a hyperfibrinolytic state associated with bleeding, thrombosis and potential membrane oxygenator dysfunction. However, the routine use of plasma free haemoglobin has certain limitations: it is not universally available in all laboratories, it is prone to error due to traumatic sampling, spectrophotometric methods are susceptible to interference from bilirubin and lipaemia and it can take considerable time to perform.
Anzeige
Carboxyhaemoglobin is also used as a marker of intravascular haemolysis. Free haem is degraded by haem oxygenase into biliverdin, free iron and carbon monoxide. This is the primary source of endogenous carbon monoxide production. Several case reports have demonstrated dramatically elevated carboxyhaemoglobin in the setting of haemolysis on ECMO, with no reported cases surviving [3, 4]. There is also evidence of low-level elevation in almost half of veno-venous ECMO patients [5]. The use of carboxyhaemoglobin as a marker of haemolysis has several benefits. It is widely and rapidly available on routinely collected blood gases through co-oximetry, and it is not susceptible to elevation due to traumatic sampling.
In our centre, evidence of haemolysis frequently results in an ECMO circuit exchange. Circuit-driven haemolysis is generally interrupted, normalising the plasma free haemoglobin and preventing progression to a hyperfibrinolytic state or membrane oxygenator dysfunction.
To demonstrate the possible use of carboxyhaemoglobin as a marker of haemolysis on ECMO, we analysed the blood results of four patients on veno-venous ECMO for severe respiratory failure who had circuit exchanges due to suspected intravascular haemolysis with elevated plasma free haemoglobin. Plasma free haemoglobin and carboxyhaemoglobin data were collected for the 72 h before and after ECMO circuit exchange and are presented in Fig. 1.
×
The results demonstrate that carboxyhaemoglobin levels were elevated prior to the circuit exchange in all cases and correlated with acute rises in plasma free haemoglobin. In patients 1–3, carboxyhaemoglobin levels then fell over the subsequent days post-circuit exchange. Patient 4 showed the same correlation, however died of suspected overwhelming sepsis with diffuse intravascular coagulation 30 h post-circuit exchange.
Anzeige
These preliminary results suggest carboxyhaemoglobin is potentially a novel marker of haemolysis on ECMO and may be useful as an indicator for ECMO circuit exchange. Further well-designed prospective studies are needed to investigate whether the relationship between carboxyhaemoglobin and intravascular haemolysis during ECMO is more widespread, and whether it has a clinically useful role in the management of ECMO patients.
Declarations
Consent for publication
The requirement to consent for publication was waived by the Alfred Hospital Ethics Committee due to the retrospective nature of the research, and de-identified data had no foreseeable physical, psychological, social, financial or cultural risks to participants and there was adequate protection of their privacy and confidentiality.
Ethics approval
Research ethics approval was granted by the Alfred Hospital Ethics Committee (Project 332/19).
Competing interests
No competing interests to declare.
Open AccessThis article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data.
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Der optimale Ansatz für die Blutdruckkontrolle bei Patientinnen und Patienten mit akutem Schlaganfall ist noch nicht gefunden. Ob sich eine frühzeitige Therapie der Hypertonie noch während des Transports in die Klinik lohnt, hat jetzt eine Studie aus China untersucht.
Laut einer Studie aus den USA und Kanada scheint es bei der Reanimation von Kindern außerhalb einer Klinik keinen Unterschied für das Überleben zu machen, ob die Wiederbelebungsmaßnahmen während des Transports in die Klinik stattfinden oder vor Ort ausgeführt werden. Jedoch gibt es dabei einige Einschränkungen und eine wichtige Ausnahme.
Eine ältere Frau trinkt regelmäßig Sennesblättertee gegen ihre Verstopfung. Der scheint plötzlich gut zu wirken. Auf Durchfall und Erbrechen folgt allerdings eine Hyponatriämie. Nach deren Korrektur kommt es plötzlich zu progredienten Kognitions- und Verhaltensstörungen.
In der Notaufnahme wird die Chance, Opfer von häuslicher Gewalt zu identifizieren, von Orthopäden und Orthopädinnen offenbar zu wenig genutzt. Darauf deuten die Ergebnisse einer Fragebogenstudie an der Sahlgrenska-Universität in Schweden hin.
Update AINS
Bestellen Sie unseren Fach-Newsletter und bleiben Sie gut informiert.