An observational study to determine the effect of delayed admission to the intensive care unit on patient outcome.

Introduction: Delayed patient admission to the intensive care unit (ICU) due to lack of bed availability is a common problem, but the effect on patient outcome is not fully known.

Methods: A retrospective study was performed using departmental computerised records to determine the effect of delayed ICU admission and temporary management within the operating theatre suite on patient outcome. Emergency surgical and medical patients admitted to the ICU (2003 to 2007) were divided into delay (more than three hours from referral to admission) and no-delay (three or fewer hours from referral to admission) groups. Our primary outcome measure was length of ICU stay. Secondary outcome measures were mortality rates and duration of organ support.

Results: A total of 1,609 eligible patients were included and 149 (9.3%) had a delayed admission. The delay and no-delay groups had similar baseline characteristics. Median ICU stay was 5.1 days (delay) and 4.5 days (no-delay) (P = 0.55) and ICU mortality was 26.8% (delay) and 24.2% (no-delay) (P = 0.47). Following adjustment for demographic and baseline characteristics there was no difference in either length of ICU stay or mortality rates between groups. ICU admission delay was associated with both an increased requirement for advanced respiratory support (92.3% delay vs. 76.4% no-delay, P <0.01) and a longer time spent ventilated (median four days delay vs. three days no-delay, P = 0.04).

Conclusions: No significant difference in length of ICU stay or mortality rate was demonstrated between the delay and no-delay cohorts. Patients within the delay group had a significantly greater requirement for advanced respiratory support and spent a longer time ventilated.