A decade of intensive care unit trauma admissions in Auckland

AIMS: To describe the demographics, nature and severity of injury of trauma admissions to a New Zealand urban Intensive Care Unit (ICU) over a ten year period; to determine differences in injury characteristics between patients received from inside and outside the local trauma catchment area; and to calculate incidence rates in the local population served, to identify high risk groups of patients. METHODS: We carried out a cross-sectional analysis of a prospective ICU patient registry. Data on all trauma admissions from 1988 to 1997 to the ICU of a large New Zealand urban hospital were studied with respect to age, gender, ethnicity, injury type and severity, and referral status. National Census data for the ICU catchment area were used to calculate incidence rates for local admissions. RESULTS: A total of 2305 trauma patients were admitted over the period of the study, accounting for 25% of all ICU admissions. The median age was 28 years and 75% were males. Blunt trauma, mostly due to motor vehicle crashes, accounted for 95% of admissions and penetrating trauma was very rare. The median Injury Severity Score (ISS) was 26 and most life threatening injuries occurred in the head region. Referred admissions were more severely injured and had a higher prevalence of severe head injury than local admissions. The ICU trauma admission rate for local patients was 34.6 per 100,000 person-years. Males had a higher rate than females in all age groups. New Zealand Europeans made up the majority of admissions, but Maori and Pacific Island males had the highest incidence rates. CONCLUSIONS: This study identified trauma as a major component of the ICU population. ICU trauma admissions were characterised by young males with head injuries resulting from motor vehicle crashes. Referred admissions were more severely injured than local admissions and would thus distort the estimated incidence of trauma in the local geographic region served. Calculation of incidence rates highlighted a significantly higher risk of ICU trauma admission amongst Maori and Pacific Islands people than New Zealand Europeans.