Yaseen Arabi, Samir Haddad, Nehad Shirawi and Abdullah Al Shimemeri
We should like to thank Dr Kanna and colleagues for their letter.
In our article  we addressed the issue of differences in baseline characteristics, namely whether maxillofacial injuries or spinal cord injuries were present. Using multivariate analysis, we found late tracheostomy (odds ratio 6.9, 95% confidence interval 2.6–18.1; P < 0.001) and, to a much lesser extent, spinal cord injury (odds ratio 4.7, 95% confidence interval 0.99–22.6; P = 0.052) to be independent predictors of prolonged ICU stay.
As we indicated in our report, the study was based on an ICU database, and therefore details regarding the reason for intubation and mode of weaning were not available. However, our trauma patients (like other trauma patients) are typically intubated for airway protection as part of their initial resuscitation.
The purpose of our study was to examine the impact of tracheostomy timing in trauma patients – a population that is typically young and free from medical comorbidities. According to Acute Physiology and Chronic Health Evaluation II definitions for chronic illnesses , there was only one patient with chronic renal failure in the early tracheostomy group and one patient with chronic respiratory insufficiency in the late tracheostomy group, and no patients had chronic cardiac or liver disease or immunosuppression. Therefore, no conclusions could be drawn from our study regarding the impact of medical comorbidities. However, we disagree with the assertion by Kanna and colleagues that no benefit has been demonstrated for early tracheostomy in medical (as opposed to surgical) patients. A recent prospective, randomized controlled trial in medical patients found significant reductions in mortality rate, incidence of pneumonia and LOS .
We were surprised by the statement by Dr Kanna and colleagues that the ICU LOS was 'the same in both groups'. This was not the case because the main finding in our study was a significant reduction in ICU LOS (10.9 ± 1.2 days for the early tracheostomy group versus 21.0 ± 1.3 days for late tracheostomy patients; P < 0.0001). Because our patients were discharged at comparable periods after tracheostomy, as shown in Table 2 of our report , the difference in ICU LOS could only be explained by the reduction in pretracheostomy duration (i.e. the timing of tracheostomy, or days from ICU admission to tracheostomy: 4.6 ± 0.5 days versus 14.1 ± 0.5 days; P < 0.0001).
We agree that ICU discharge practices vary among institutions, but this is unlikely to affect the results and implications of our study because the comparison is made between two groups cared for in the same institution, by the same physicians and using the same discharge practices.