11 August 2021
Should we be using chlorhexidine dressings with external ventricular drains?
External ventricular drain insertion is a commonly performed, life-saving neurosurgical procedure. Unfortunately, about 10% of patients experience an EVD infection. The consequences can be devastating for patients and their families, often requiring prolonged administration of antibiotics, further surgery and a longer hospital stay. But could a simple intervention like a chlorhexidine dressing help prevent these infections?
Mueez Waqar is a neurosurgical trainee and CRUK PhD fellow. Abdurrahman Islim is an incoming NIHR academic neurosurgical trainee.

The elephant in the room

EVD insertion is a life-saving procedure performed across the world and the commonest procedure we do in neurosurgery. It is done in an emergency to relieve fluid that can build up after a head injury, stroke, or cancer, which can block the brain’s fluid pathways. Unfortunately, about 1 in 10 patients experience an EVD infection, which can change patients’ and relatives’ lives forever. It can lead to prolonged antibiotics, further surgery, a longer hospital stay and a worse neurological outcome for patients. The overall costs of care may also double at least!

What has been done so far to avert this issue?

To date, we have tried several strategies to reduce EVD infections. These have included silver and antibiotic impregnated drains, prophylactic and prolonged antibiotic administration and the use of EVD care bundles. However, more still needs to be done as shown by the high infection rate!

Drawing on experience with arterial and central lines (Shush! Don’t tell the intensivists)

An EVD is an indwelling catheter so we drew inspiration for this review from other types of indwelling catheters such as central lines and arterial lines. The source of infection from these lines is usually the patient's own skin flora. To this end, dressings containing the antiseptic chlorhexidine have been tested in randomised controlled trials and have been shown to reduce the risk of line infections.

In common with line infections, EVD infections also usually arise from skin organisms, so chlorhexidine dressings may be beneficial for patients with EVDs. In this review, we sought to test the hypothesis whether chlorhexidine dressings could reduce the frequency of EVD infections. Overall, we found that there is a lack of good quality evidence to properly test our hypothesis. However, the limited evidence available does suggest that chlorhexidine dressings may reduce the risk of EVD infections (infection rate 1.7% vs. 7.9%).

What’s next?

Although there is currently a lack of good quality evidence to properly test our hypothesis, our findings do strongly suggest there is an urgent need to test the efficacy of chlorhexidine dressings for EVDs in a future randomised controlled trial. This simple and cost effective intervention could dramatically alter EVD outcomes across the world if it is found to be efficacious.

Together with the Society of British Neurological Surgeons (SBNS) and the British Neurosurgical Trainees Research Collaborative (BNTRC), we hope to further explore this area so stay tuned! We will provide further updates on Twitter (@waqar_nsurg) as this project moves forwards – so show some support / reach out to us there!

You can read the JHI article by Mueez Waqar and colleagues here:

Waqar M, Chari A, Islim AI, Davies B, Fountain DM et al Chlorhexidine dressings could reduce external ventricular drain infections: results from a systematic review and meta-analysis Journal of Hospital Infection, In Press, 2021.