Aim: To evaluate rates of unplanned ICU admissions before, during and after New Zealand's COVID-19 Alert Level 4/3 lockdown, and to describe the characteristics and outcomes of patients admitted to Wellington ICU during lockdown in comparison to historical controls.
Method: We conducted a retrospective cohort study using the Wellington Hospital ICU database and included patients with an unplanned ICU admission during the first 35 weeks of the year from 2015 to 2020 inclusive. The primary variable of interest was the rate of unplanned ICU admission in 2020 compared with historical controls. We also described the characteristics and outcomes of patients with unplanned admissions to ICU during the 2020 COVID-19 lockdown compared to historical controls.
Results: During the five weeks of Alert Level Four, and the subsequent two weeks of Alert Level Three, the number of unplanned ICU admissions per day fell to 1.65±1.52 compared to a historical average of 2.56±1.52 ICU unplanned ICU admissions per day (P<0.0001). The observed reduction in ICU admission rates appeared to occur for most categories of ICU admission diagnosis but was not evident for patients with neurologic disorders. The characteristics and outcomes of patients who had unplanned admissions to Wellington ICU during the COVID-19 lockdown were broadly similar to historical controls. The rate of unplanned ICU admissions in 2020 before and after the lockdown period were similar to historical controls.
Conclusion: In this study, we observed a reduction in unplanned admissions to Wellington Hospital ICU associated with New Zealand's initial COVID-19 lockdown.