The randomisation-list in the institute of pharmacy University Hospital Inselspital Bern will only be accessible to unblinded employees. In case of unblinding an authorized member of the blinded trial team contacts the 24-hours service-number of the pharmacist on-duty in the institute of pharmacy. After disclosure of the patient-number, the pharmacist on-duty performs the unblinding and informs the authorized unblinded trial-member about allocation. Finally unblinding is registered on the randomization list by the pharmacist on-duty.