# Cold-stored platelets: A systematic review of recovery in healthy adults and chest drain output in cardiothoracic surgery patients

## TL;DR

This study reviews cold-stored platelets and finds they reduce chest cavity bleeding after surgery, despite lower recovery rates compared to room-temperature platelets.

## Contribution

The study provides new evidence on the effectiveness of cold-stored platelets in reducing post-surgical bleeding in cardiothoracic patients.

## Key findings

- Cold-stored platelets had a 25.85% lower in vivo recovery compared to room-temperature platelets.
- Cold-stored platelets reduced chest drain output by 249.68 mL in cardiothoracic surgery patients.
- Cold-stored platelets may be optimal for managing bleeding in surgical patients despite logistical challenges.

## Abstract

Cold-stored platelets were abandoned in the 1960s after demonstration of an increased clearance in vivo due to an irreversible activated phenotype. Difficulties in storage, logistics, and the increased requirement of therapeutic platelet transfusions for haemostasis have sparked renewed interest in cold-stored platelets. This systematic review compared two primary outcomes: in vivo recovery for autologous cold-stored platelets versus room-temperature platelets in healthy volunteers, and chest drain output at 24 h for allogeneic cold-stored platelets versus room-temperature platelets after complex cardiothoracic surgery. A total of 4215 articles were found in the ProQuest, PubMed, Scopus, Embase, and Cochrane electronic databases. Seven eligible papers were included in this meta-analysis. Cold-stored platelets showed a decreased in vivo recovery two hours after retransfusion following storage for two to seven days compared to a room-temperature platelet control group (mean difference: −25.85 %; 95 % confidence interval: −41.98 to −9.71 %; p-value = 0.002). Further, cold-stored platelets showed a decreased chest cavity output when transfused within 24 h after complex cardiothoracic surgery (mean difference: 249.68 mL; 95 % confidence interval: 85.68 to 413.67 mL; p-value = 0.003). While cold-stored platelets are not a substitute for room-temperature platelets in a prophylactic scenario, their ability to significantly reduce chest cavity output suggests they may be optimal for the management of bleeding in surgical patients, especially in the context of logistical difficulties.