A prolonged ICU stay after interhospital transport?

Transport of critically ill patients can be complicated[1-3]. Barratt and colleagues studied patients transferredfor nonclinical reasons to evaluate the consequences oftransportation [4]. Th ere was no diff erence in mortalitybut the ICU length of stay (LOS) increased by 3 days,which was explained as a negative impact of the transporton patient physiology. We disagree with this conclusion.First, by including only transports to level 3 ICUs thereceived level of care for transported patients willincrease, introducing a bias.Second, the increase in LOS can be interpreted as aresult of selection bias, because patients with a shortexpected LOS would often not be considered eligible fortransport. Also, since there was no increase in mortality,which would have been expected with an increased LOS,we might be looking at a mortality reduction as a resultof the transfer to a higher-level ICU.Th ird, Barrett and colleagues suggest that deteriorationof patient physiology during transport is probably responsible for the increase in LOS. However, the reportedIntensive Care National Audit and Research Centrescores before and after transport (although not validatedfor sequential patient assessments) do not support thisassumption.Fourth, the method of transportation should have beenincluded in this study. Specialised transport teams deliverpatients with a better acute physiology compared withnonspecialised teams [2,5], making a need for regainingphysiological stability unlikely.In conclusion, we congratulate Barratt and colleaguesfor their research. However, we think their conclusion ispremature because multiple possible confounders werenot taken into account