Randomisation, allocation concealment and blinding
All contributing studies are randomised controlled studies. At randomisation each participant is assigned to nebulised heparin or standard care in a one-to-one allocation ratio. Allocation concealment is performed at the level of each study as specified in the respective study protocols. All contributing studies are open label by design. The meta-trial data analysts are blinded. Unblinding is permissible when pre-specified Bayesian stopping rules for efficacy or safety have been met.