In my opinion the use of conventional lifts for evacuation in hospitals is perfectly valid providing that the approriate risk assessments are undertaken and any necessary measures are set in place. Due to the size and relative complexity of hospital buildings there are often circumstances when perfectly functioning lifts and thier power supplies, controls etc. are remote both physically and in terms of fire protection from any fire incident and could continue to operate safely.
HTM 05-03 Part E addresses the specific issues and appropriate measures when vertical evacuation of patients using lifts is considered as part of the evacuation startegy. Usually this approach is take when either there are insufficient stair provisions or when a particular need has been identified such as a limited potential for horizontal evacuation particularly if it involves the evacuation of ITU.
