Clinical impact of rotational thromboelastometry in cardiac surgery

Pre-operative reference ranges for ROTEM® sigma in patients undergoing cardiac surgery: a secondary analysis of two prospective trial cohorts

INTRODUCTION

Rotational thromboelastometry (ROTEM®) is used widely in cardiac surgery. Reference ranges are derived from healthy volunteers but may not be interchangeable with those from patients undergoing cardiac surgery. Furthermore, sex and age seem to influence rotational thromboelastometry profiles. We performed a secondary analysis of two prospective observational study cohorts from a single centre in the Netherlands, which establishes pre-operative ROTEM® sigma reference ranges for adult patients undergoing cardiac surgery and examines sex- and age-specific variations.

METHODS

Reference ranges (2.5-97.5th percentiles) were compared with those reported by the manufacturer by calculating 95%CIs around the percentiles. Sex- and age-specific variations were evaluated similarly by creating subgroups (comparing males with females and different age groups) and calculating the 95%CIs for the ranges in each subgroup. Non-overlapping CIs indicated statistically significant different ranges.

RESULTS

We included 381 patients in the analysis. Differences were found in ROTEM sigma reference ranges compared with those stated by the manufacturer: EXTEM and FIBTEM clot firmness upper limits were higher, and clotting time ranges in EXTEM and INTEM were wider. The lower limit of LI60 EXTEM was lower. When comparing males (n = 260) and females (n = 121), female patients had shorter CT EXTEM and higher A5, A10 and MCF in EXTEM and FIBTEM, but the reference ranges were not significantly different. No differences in medians or reference bounds were found across four age categories, divided by quartiles.

DISCUSSION

Reference ranges for patients undergoing cardiac surgery differed from the manufacturer reference ranges. Pre-operatively, female patients exhibited a slightly more hypercoagulable ROTEM profile than males when comparing medians, though the reference ranges were similar. No differences were found across age categories. Cardiovascular-specific, but not sex- or age-specific ROTEM sigma reference ranges might be needed.

Implementation of Patient Blood Management in Orthotopic Heart Transplants: A Single Centre Retrospective Observational Review

BACKGROUND

Blood transfusion in the perioperative cardiothoracic setting has accepted risks including deep sternal wound infection, increased intensive care unit length of stay, lung injury, and cost. It has an immunomodulatory effect which may cause allo-immunisation. This may influence long-term survival through immune-mediated factors. Targeting coagulation defects to reduce unnecessary or inappropriate transfusions may reduce these complications.

METHODS

In 2012, an institution-wide patient blood management evidence-based algorithmic bleeding management protocol was implemented at The Prince Charles Hospital, Brisbane, Australia. The benefit of this has been previously reported in our lung transplant and cardiac surgery (excluding transplants) cohorts. This study aimed to investigate the effect of this on our orthotopic heart transplant recipients.

RESULTS

After the implementation of the protocol, despite no difference in preoperative haemoglobin levels and higher risk patients (EuroSCORE 20 vs 26; p=0.013), the use of packed red blood cells (13.0 U vs 4.4 U; p=0.046) was significantly lower postoperatively and fresh frozen plasma was significantly lower both intra- and postoperatively (7.4 U vs 0.6 U; p<0.001, and 3.3 U vs 0.6 U; p=0.011 respectively). Concurrently, the use of prothrombin complex concentrate (33% vs 78%; p<0.001) and desmopressin (5% vs 22%; p=0.0028) was significantly higher in the post-protocol group, while there was less use of recombinant factor VIIa (15% vs 4%; p=0.058). Intraoperative units of cryoprecipitate also rose from 0.9 to 2.0 (p=0.006).

CONCLUSIONS

We have demonstrated that a targeted patient blood management protocol with point-of-care testing for heart transplant recipients is correlated with fewer blood products used postoperatively, with some increase in haemostatic products and no evidence of increased adverse events.