Does the introduction of HDU reduce surgical mortality?

The aim of this study was to assess the change in workload in a general surgery department over 2 consecutive 1-year periods and document the impact of a high dependency unit (HDU) on hospital mortality. Data were collected on all admissions, the number and type of operations performed for a 1-year period before and after a purpose-built HDU was opened. During the study period, the total number of admissions increased by 15%, with a disproportionately large increase (27%) in the number of emergency admissions. This was reflected by increases in the emergency out-of-hours operating by 12%. During the study period, the overall in-patient mortality rose from 2.16% to 3.2%. Introduction of HDU facilities alone does not lead to a reduction in hospital mortality. Alterations in emergency workload and changes in case-mix are important in determining outcome. League tables of hospital mortality are likely to be difficult to interpret without adequate information about facilities and case-mix.