Impact of a new high dependency unit: An analysis of activity patterns in a HDU and its impact on ICU utilization

Abstract

Objective: To determine High Dependency Unit (HDU) utilization patterns over time and its impact on Intensive Care Unit (ICU) workload. Design: Retrospective analysis of prospectively collected data. Setting: High Dependency and Intensive Care Units of an Irish University Hospital. Subjects: Data prospectively collected on all HDU admissions was analyzed for the first 6 months of operation and comparable 3-month periods during years 2 and 4. ICU workload was assessed by comparing ICU admissions by speciality, length of ICU stay, and need for ventilatory support before and after HDU opening. Interventions: None Measurements and main results: Demographic data, reason for admission, patient source, admitting speciality, length of HDU stay, and discharge destination were analysed. ICU data included casemix, length of stay, and requirement for ventilatory support. Seventy four percent of HDU admissions were from the cardiothoracic, vascular and general surgical specialities. The mean HDU stay was 2.1 days, with a Male:Female ratio of 1.8:1, mean age 59.6 years, and occupancy rate of 80.5%. 88.1% were discharged to the ward, 5.5% required ICU admission, with HDU mortality 1.1% during the first 6 months. HDU utilization evolved over time, with increased admissions directly from the operating theatre, more vascular surgical admissions, and longer length of stay. ICU patients requiring intubation and/or assisted ventilation increased from 61.3% to 80.3%. Conclusions: Our HDU has proven a useful, highly utilised resource, and has played a central role in the evolution of perioperative care reserving the ICU for more severely ill patients.