Test may halve ICU antibiotic use

Blood testing ICU patients for a hormone that indicates bacterial infection could reduce the use of antibiotics, claim Swiss researchers.

They assessed a protocol that measures levels of procalcitonin (PCT) – a hormone produced by the body in the presence of severe bacterial infection and a known indicator of sepsis.

Widely used in mainland Europe, PCT assays are used by some UK hospitals to diagnose infection as a cause of inflammation – but not currently as a guide for the duration of antibiotic therapy.

Researchers randomly assigned 72 ICU patients with severe sepsis or septic shock to an intervention or control group. The intervention group was treated using a protocol where antibiotic cessation decisions were based on bloodstream levels of PCT.

The control group received antibiotic treatment according to a previously defined clinical protocol unrelated to PCT.

Patients in the intervention group spent an average of six days on antibiotics, compared with 12.5 days in the control group. In addition, intervention patients spent just 17 days in hospital compared with the control group average of 23.5 days.

Critical care nurses were cautious about the findings. Sarah Clarke, service improvement nurse lead at Cheshire and Mersey Critical Care Network, said: 'Although this could be used as a tool to help patient management, as far as I am aware most UK critical care units don't give antibiotics longer than seven to eight days anyway.

'Having a strict antibiotic policy in place should be the first step, and good links with microbiology are essential. Only then should other methods to tighten practice be considered,' she added.

Andrea Baldwin, service improvement nurse lead at Lancashire and South Cumbria Critical Care Network, added: 'I am not aware of using PCT levels within critical care units [in the UK] to determine use of antibiotics. A larger, multi-centred trial would need to take place to support these findings before I would support implementation of this protocol.'

American Journal of Respiratory and Critical Care Medicine (2008) 177: 498–505