Patients were excluded from the protocol if they were
deaf; as they would not be able to listen to music, or
pregnant, needing a SAS 1 or 2 or neuromuscular blockade.
All patients were screened and recruited at the CHUS MICU
of Fleurimont which is a 16-bed mixed medical-coronary
unit for adult patients with an average annual admission rate
of approximately 1000/year. The trial was conducted from
Jan 2009 to April 2011 and 720 patients were maintained at
least 1 day on invasive MV during this period.
A computer-generated block randomization list was
prepared by the investigators. Randomization was concealed
using numbered, opaque sealed envelopes and was revealed
by an ICU staff member not involved in the direct care of the
randomized patient. This staff member took a first blood
sample and recorded baseline vital signs (VS) as well as
sedative infusion rates (step 1); positioned the music system
(ie, MP3) on the patient's head and started the listening
period (step 2); and repeated step 1 procedures at the end of
the listening period (step 3). All efforts were made to avoid
any nonurgent interventions from steps 1 to 3.