Forty-eight-hour cold-stored whole blood in paediatric cardiac surgery: Implications for haemostasis and blood donor exposures.

Background and objectives: Cold-stored whole blood (CS-WB) in paediatric cardiac surgery is making a resurgence, given its identified benefits compared to conventional blood component therapy (CT).

Study design and methods: A single-centre retrospective study was conducted from January 2018 to October 2018 by including children <18 years of age undergoing cardiac surgery requiring cardiopulmonary bypass. ABO-compatible CS-WB from non-directed random donors was leukoreduced with platelet-sparing filters and compared with CT.

Results: Fifty-seven patients (30, 53% CS-WB; 27, 47% CT) were studied. Patient demographics were similar, although CT patients were cooled to a lower intra-operative temperature. Blood product requirements 24 h post operation were less in the CS-WB group (11.1 vs. 26.7 mL/kg, p = 0.048). Twelve (40%) patients in the CS-WB cohort had more than one donor exposure versus 25 (93%) in the CT group (p < 0.001). CT patients compared to CS-WB patients had a greater decrease in pre-operative versus 48-h post-operative haemoglobin, platelets and prothrombin time. Patients who received CT compared to CS-WB had a trend towards higher median (interquartile range [IQR]) chest-tube output (mL/kg/h) in the first 4 h post cardiac intensive care unit (ICU) admission (2.1 [0.8, 3] vs. 1.6 [0.8, 2.2], p = 0.197). There was no difference in antifibrinolytic use, length of stay, sepsis, acute kidney injury or wound infection. Survival to discharge was similar.

Conclusion: CS-WB in paediatric cardiac surgery may reduce donor exposure and improve haemostatic balance. Future multi-centre prospective studies are needed to validate these findings and identify patients who would benefit from CS-WB in paediatric cardiac surgery.