Ploeg, E. van der (Eke) (2019) Heparin Rebound and Platelet Dysfunction: Two Phenomena in Cardiopulmonary Bypass Surgery and Their Associations with Postoperative Blood Loss. thesis, Medicine.
Full text available on request.Abstract
Postoperative bleeding is one of the main complications of cardiothoracic surgery with cardiopulmonary bypass (CPB). Heparin rebound and platelet dysfunction are two phenomena that could partially explain this. This study investigates whether heparin rebound and platelet function are associated with postoperative bleeding. Next to that, the reversibility of CPB induced platelet dysfunction is analysed. Methods For the interim analysis of this prospective observational study, measurements were done in 32 patients who underwent cardiothoracic surgery with CPB. Thromboelastography (TEG), multiple electrode aggregometry (MEA), activated clotting time (ACT), and laboratory measurements were done at five different time points between induction of anaesthesia and 4 h after protamine administration. The difference in TEG reaction time with and without heparinase (∆R) was used as a measure to detect heparin. MEA results were used to measure platelet function. Results ∆R was .67 min higher 4 h after protamine administration (T4) compared with baseline (T0) (p < .001). There was no association between the change of ∆R between the different time points and chest drainage after 24 h, and neither between the change of ∆R between the different time points and transfusion requirement. Platelet function did not statistically differ between T0 and T4. Platelet function at T4 was significantly associated with chest drainage after 24 h in adenosine diphosphate (ADP) and arachidonic acid (ASPI) tests (ADP, R2 = .22 and p = .007; ASPI, R2 = .15 and p = .032). At T0 there was a similar association, but this was not significant (ADP, R2 = .09 and p = .096; ASPI, R2 = .12 and p = .057). There were no associations between the change in platelet function between T0 and T4 and chest drainage. Conclusion With ∆R taken as the measure, there is more heparin present in the blood 4 h after protamine administration than after induction of anaesthesia. This indicates the presence of heparin rebound. However, the difference that was found was small and might not be clinically relevant. There was no association between this heparin rebound and postoperative blood loss. Platelet function was found to be completely reversible 4 h after protamine administration. There was no association between the change in platelet function between T0 and T4 and postoperative blood loss, which corresponds with the finding that platelet function has returned to normal after this time
| Item Type: | Thesis (Thesis) |
|---|---|
| Supervisor name: | Faculty supervisor: and Absalom, Prof. Dr. A.B. and anaesthetist |
| Supervisor name: | Daily supervisor: and Vlot, Drs. E.A. and anaesthetist-intensivist and Deparment: Anaesthesia and Institution: St. Antonius Ziekenhuis, Nieuwegein |
| Faculty: | Medical Sciences |
| Date Deposited: | 25 Jun 2020 11:00 |
| Last Modified: | 25 Jun 2020 11:00 |
| URI: | https://umcg.studenttheses.ub.rug.nl/id/eprint/2017 |
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