Abstract

BACKGROUND This pilot trial focused on feasibility and safety to provide preliminary data to evaluate the hemostatic potential of cold-stored platelets (2° to 6°C) compared with standard room temperature-stored platelets (20° to 24°C) in adult patients undergoing complex cardiothoracic surgery. This study aimed to assess feasibility and to provide information for future pivotal trials. METHODS A single center two-stage exploratory pilot study was performed on adult patients undergoing elective or semiurgent complex cardiothoracic surgery. In stage I, a two-armed randomized trial, platelets stored up to 7 days in the cold were compared with those stored at room temperature. In the subsequent single-arm stage II, cold storage time was extended to 8 to 14 days. The primary outcome was clinical effect measured by chest drain output. Secondary outcomes were platelet function measured by multiple electrode impedance aggregometry, total blood usage, immediate and long-term (28 days) adverse events, length of stay in intensive care, and mortality. RESULTS In stage I, the median chest drain output was 720 ml (quartiles 485 to 1,170, n = 25) in patients transfused with room temperature-stored platelets and 645 ml (quartiles 460 to 800, n = 25) in patients transfused with cold-stored platelets. No significant difference was observed. The difference in medians between the room temperature- and cold-stored up to 7 days arm was 75 ml (95% CI, -220, 425). In stage II, the median chest drain output was 690 ml (500 to 1,880, n = 15). The difference in medians between the room temperature arm and the nonconcurrent cold-stored 8 to 14 days arm was 30 ml (95% CI, -1,040, 355). Platelet aggregation in vitro increased after transfusion in both the room temperature- and cold-stored platelet study arms. Total blood usage, number of adverse events, length of stay in intensive care, and mortality were comparable among patients receiving cold-stored and room temperature-stored platelets. CONCLUSIONS This pilot trial supports the feasibility of platelets stored cold for up to 14 days and provides critical guidance for future pivotal trials in high-risk cardiothoracic bleeding patients.

Abstract

INTRODUCTION The use of cardiopulmonary bypass (CPB) leads to increased fluid filtration and edema. The use of artificial colloids to counteract fluid extravasation during cardiac surgery is controversial. Beneficial effects on global fluid loading, leading to better cardiac performance and hemodynamics, have been claimed. However, renal function and coagulation may be adversely affected, with unfavorable impact on outcome following cardiac surgery. METHODS Forty patients were randomly allocated to study groups receiving either acetated Ringer's solution (CT group) or hydroxyethyl starch (HES group, Tetraspan((R))) as CPB priming solution. Fluid balance, bleeding and hemodynamics, including cardiac output, were followed postoperatively. The occurrence of acute kidney injury was closely registered. RESULTS Two patients were excluded from further analyzes due to surgical complications. Fluid accumulation was attenuated in the HES group (3374 (883) ml) compared with the CT group (4328 (1469) ml) (p=0.024). The reduced perioperative fluid accumulation was accompanied by an increased cardiac index immediately after surgery (2.7 (0.4) L/min/m(2) in the HES group and 2.1 (0.3) L/min/m(2) in the CT group (p<0.001)). No increase in bleeding could be demonstrated in the HES group. Three patients, all of them in the HES group, experienced acute kidney injury postoperatively. CONCLUSIONS CPB priming with HES solution lowers fluid loading during bypass and improves cardiac function in the early postoperative period. The manifestation of acute kidney injury exclusively in the HES group of patients raises doubts about the use of HES products in conjunction with cardiac surgery. ( https://clinicaltrials.gov/ct2/show/NCT01511120 ).