Impact of increasing overnight intensive care unit registrar staffing on duration of intubation of elective cardiac surgery patients.

It is unclear whether increases to overnight junior medical staffing levels can improve ICU patient outcomes. We conducted a retrospective cohort study before and after the introduction of a third overnight ICU registrar at a 24-bed metropolitan ICU in February 2012. We hypothesised that this change would be associated with decreased intubation time for elective cardiac surgery patients and an increase in the proportion of these patients being extubated during the overnight period. All elective cardiac surgery patients were included from two temporally matched six-month periods (May to October) in 2011 and 2012. The primary outcome was median duration of intubation, and the secondary outcome was proportion of patients extubated during the 'overnight' period (2200 to 0700). A total of 142 and 188 patients were included in the control and intervention cohorts, respectively. Median (IQR) intubation time was 8.7 (6.6 to 14.5) hours in the control cohort and 8.2 (6.0 to 13.4) hours in the intervention cohort, with no significant difference between groups (P=0.40). The proportion of elective cardiac surgery patients extubated during the overnight period was similar, 54.2% in the control group compared to 50.0% in intervention group (P=0.45). In our unit, increasing overnight ICU registrar staffing levels was not associated with a significant reduction in duration of intubation for elective cardiac surgery patients or a reduction in the proportion of these patients extubated overnight. This is likely due to factors other than medical staffing levels influencing timing of extubation of these patients.