A great new little study has just been published in Infection Prevention in Practice by Mark Garvey and colleagues up in Birmingham investigating the sink splash zone in the ICU. The study certainly does identify elements of danger in the sink splash zone, and provides evidence of tangible transmission risk for Pseudomonas and other water-borne pathogens in the ICU.

The study used a simple but effective technique to explore how much and how far water splashes into a 2m “sink splash” radius during the use of sinks in the ICU. Absorbent paper towels were laid out around a sink, and the degree which splashing occurred was evaluated with the tap running (a bit of splash, Figure panel A) and after hand hygiene (quite a bit of splash, Figure panel B). Quite a similar approach to Peter Hoffman’s “light coloured trouser test”. (For those of you who haven’t heard this explained, Peter stands by the sink in light coloured trousers and sees how much splash-back occurs!)

The team also observed what types of equipment and patients found their way into the sink splash zone (Figure, panel C. And you name it, they found it: all kinds of IV equipment and medication, electronic equipment, medical devices, and a range of patients (including immunosuppressed patients with multiple IV lines). This isn’t a failure of process or procedure in this ICU but rather a reflection of how things would be in pretty much every ICU you walk onto in the world.

Figure: The sink splash zone. Panel A: after running the tap. Panel B: after hand hygiene. Panel C: equipment in the sink splash zone.

This study provides more evidence that we need to think really carefully about the risk balance of how we use water to deliver care. It would be wise to avoid putting anything in the sink splash zone, but especially items that are going to be used to care for vulnerable patients who are susceptible to Pseudomonas infection. Perhaps the solution here is to get risk of the sinks altogether and go water-free; no sink = no sink splash (danger) zone!

(And couldn’t resist the Top Gun reference!)