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We thank Lyness and Mallett for their interest in our article 1. Hypercoagulability can be detected with rotational thromboelastography (ROTEM®) as shortened clotting time (CT) and clot firmness time (CFT) and/or increased alpha angle and maximum clot firmness (MCF). Thorson et al. 2 specified hypercoagulability as any ROTEM variable (CT, CFT, MCF in INTEM or EXTEM, or MCF of FIBTEM) lying outside the reference range. However, universal diagnostic criteria of hypercoagulation in ROTEM are still not defined. In our study, we did not aim to diagnose postoperative hypercoagulation but to compare postoperative blood coagulability when intra-operative magnesium sulphate was or was not used. Even though all of the variables were within normal ranges, the differences in MCFs in INTEM, EXTEM and FIBTEM between the two groups were significant on the third postoperative day, meaning that blood coagulability was affected by intra-operative administration of magnesium sulphate. However, as Lyness and Mallett correctly point out, no conclusion can be drawn regarding any clinical or subclinical occurrence of thromboembolic complications. Pre- and postoperative platelet counts and fibrinogen levels were comparable between the groups (Table 1) and so we can conclude that different ROTEM results do not result from different levels of platelet or fibrinogen, but from their function, i.e. platelet aggregation or fibrin polymerisation. High thrombin generation reflects a thrombotic phenotype. Thrombin enables conversion of fibrinogen to fibrin, leading to clot formation 3, and thrombin generation is interrupted by magnesium 4, which explains our results. We are aware that the lack of statistical significance between data points at 1 h postoperatively is at odds with our previous findings 5. However, although differences were not significant, the pattern of changes 1 h postoperatively is similar in both papers. Specifically, all CTs and CFTs of INTEM and EXTEM were increased in the magnesium group. The MCFs of INTEM, EXTEM and FIBTEM were decreased in the magnesium group. Every parameter of the control group changed conversely, except the CFT of INTEM, CT of EXTEM, and MCF of FIBTEM. Third day postoperative data, which showed significant changes in the MCF of INTEM, EXTEM, and FIBTEM, cannot be compared with those from our previous study, because we collected no data at the same time point in that study. We agree wholeheartedly with Lyness and Mallett about the clinical significance of analysing ROTEM in patients undergoing orthopedic or vascular procedures, known to cause postoperative hypercoagulability, in order to investigate the change of coagulability by magnesium sulphate. However, cancer patients have already been shown to have hypercoagulability 6 and major surgery also increases procoagulant factors 7. Previous studies have shown postoperative hypercoagulability in abdominal surgery using thromboelastography (TEG®) or ROTEM 2, 8. Therefore, we think that our cohort was suitable for meeting the aims of this study. Lastly, blood loss was minimal in the cohort undergoing laparoscopic colorectal cancer surgery, so colloid expansion of intravascular volume was not administered to any patient during the peri-operative period. Lactated Ringer's solution was administered postoperatively at a rate of 40-80 ml.h-1 according to the patient's body weight in addition to total parenteral nutrition. Considering the haemoglobin levels shown in Table 1, we think it unlikely that haemodilution might have had any influence on postoperative coagulability.