Coronavirus mortality rates in ICUs here lower than other countries

The mortality rate of patients admitted to public hospital intensive care units with COVID-19 in the first wave in Australia was lower than overseas.

The mortality rate of patients admitted to public hospital intensive care units with COVID-19 in the first wave of the pandemic in Australia was lower than in other parts of the world, with four of out of five patients placed on a ventilator surviving the disease.

A study published in the Medical Journal of Australia that documented 90 per cent of COVID-19 ICU admissions up to July 5 found that the death rate for COVID-19 patients who required ventilation in ICU was 22 per cent, while the mortality rate was 5 per cent for those in ICU who did not require ventilation.

The study also revealed that public hospitals in Australia came nowhere near being overwhelmed by the pandemic. The median peak ICU bed occupancy for the 77 intensive care units that partici­pated in the study was calculated at 14 per cent.

The study, known as SPRINT-SARI, was co-ordinated by the Australian and New Zealand Intensive Care Research Centre (ANZIC-RC) at Monash University. It found that invasively ventilated COVID-19 patients had a median length stay in ICU of 16 days, compared with three days for those who were not ventilated.

The authors of the study concluded that severely ill patients’ chances of dying of COVID-19 may be lower than international studies have indicated, provided a country’s hospital system is not overwhelmed.

“The prognosis for severe COVID-19 may not be as poor as previously described, although resource utilisation may be higher,” they said. “To the end of June 2020, patients admitted to Australian ICUs with COVID-19 requiring invasive ventilation had lower mortality and a longer length of stay than reported globally. These findings highlight the importance of ensuring adequate local ICU capacity, particularly with the recent increase in COVID-19 infections in Australia.”

Previous studies that analysed the death rates of those admitted to ICU with COVID-19 in the US, Italy and China found mortality rates ranging from 40 to 90 per cent. In Britain, a large-scale randomised trial found the mortality rate among invasively ventilated patients was 40 per cent.

The SPRINT-SARI study found several factors might account for the big difference between those figures and Australia’s 22 per cent mortality rate for mechanically ventilated COVID-19 patients in ICU.

First, other countries had little time to prepare for the influx of patients and their hospitals were overwhelmed. As a result, the number of patients invasively ventilated on the first day of their ICU stay was very high; in Australia, only 39 per cent of ICU cases were ventilated in the first 24 hours.

“As the healthcare system in Australia never reached, let alone exceeded, capacity during this period, it may be that in these circumstances, patients could access the ICU earlier in the course of their illness, thereby benefiting from interventions that have been associated with lower mortality rates,” the authors said.

The 204 patients studied had a median age of 63 years and were predominantly male. Common comorbidities were obesity, diabetes and chronic cardiac disease.