Reply from the authors

concentration after the removal of CPB and administration of protamine. When a patient is bleeding, it is vital to obtain coagulation test results as soon as possible in order to avoid delays in the identification of coagulation abnormalities and facilitate early treatment and correction of bleeding. Unfortunately, standard laboratory coagulation tests often have long turnaround times, thereby delaying the identification and correction of coagulation problems. For example, the turnaround time of fibrinogen concentration measurement by the Clauss assay has been reported as 30–60 min, 7 and longer times of around 88 min have also been published. Additionally, delayed results may not accurately reflect the current haemostatic status of the patient. There is, therefore, an urgent need for an accurate, reliable, and fast method of measuring the patient’s haemostatic status. Point-of-care testing (POCT), such as the ROTEM-based FIBTEM assay, can obtain results in 5–10 min; 8 however, although POCT is widely used after cardiovascular surgery, many institutions do not yet have the necessary equipment to carry out these tests. A recent study of 26 patients undergoing CPB described plasma fibrinogen values at 60 min on CPB of 209 mg dl, comparable with those taken at the end of CPB, after administration of protamine (202 mg dl). Importantly, the mean CPB duration was 125 min. Therefore, the time point ‘60 min on CPB’ also represents close to 1 h before the end of CPB in these patients, which may be a good time point for most standard laboratories to perform coagulation testing and obtain a first estimation of the coagulation status post-CPB. Many of the current publications on haemostatic therapy with fibrinogen concentrate after CPB use the FIBTEM parameters obtained on CPB, at removal of the aortic clamp (20–30 min before the end of CPB), as a dosing tool. To date, there are no data published on fibrinogen concentration values at the same time point, although clinicians may find such information very useful. Indeed, there is already an ongoing clinical trial of fibrinogen concentrate during elective complex cardiac surgery which is using Clauss assays taken during CPB to determine the dose of fibrinogen (ClinicalTrials.gov identifier NCT01124981). With these considerations in mind, we would be interested to see further data from the study carried out by Solomon (if available). We note that blood samples were obtained from the patients both 20 min before removal of CPB and after removal from CPB/administration of protamine. The article also states that both Clauss assays and ROTEM-based FIBTEM assays were carried out on the samples, and that the dose of fibrinogen administered was based on the FIBTEM measurement taken before removal of CPB. It would be of great interest to investigate the possibility of using the fibrinogen measurements taken before the removal of CPB to determine fibrinogen dosing, and to establish whetheror not this approach would have significantlyaffectedthetreatmentthese patients received. Ifnosignificant difference is observed, this could be of clinical importance for patients with extensive surgery and high risk of bleeding after CPB, for whom delays to treatment must be minimized. Declaration of interest