4.2. Study limitations
There are several potential limitations to this study. First, a
non-randomized retrospective trial it is subject to selection bias.
Second, during the study period the CSICU was converted from an open
care model to a semi-closed model, and which may have impacted outcomes
as well. Third, in the initial period between tracheostomies were
performed by open approach by ENT surgeons, and follow tracheostomies
were performed at the bedside using the percutaneous dilatation
technique. Fourth, we don’t investigate secondary outcomes as use of
prolonged sedation, rate of VAP, length of hospital stay, and number of
ventilator-free days. It was beyond scope of the study. Five, authors
have no data on the number of patients who were discharged home/nursing
home/rehabilitation facility or remained in hospital. Also, we do not
have information on the number of decanulated patients. And sixth: we
agree that it is difficult to assess the causality of timing of
tracheostomy and long-term survival. It is possible that those who
received a later tracheostomy were not initially indicated for a
tracheostomy at all.