After written informed consent was obtained, the patients were randomly allocated to one of three therapy groups (MAD, nCPAP, or placebo; see below). To ensure that the groups were of approx. the same size, block randomisation was used. Block sizes were 6, 12, and 18; sizes were randomly varied. The allocation sequence was automatically generated and subsequently concealed by an independent co-worker, who kept a paper copy in a lockable drawer. Sealed opaque envelopes were used to conceal the allocation from the principal investigator.