Psychiatrymiddle twist
A 26-year-old woman has been an inpatient for three weeks with recurrent bloodstream infections through her central venous catheter, growing a different mix of gut organisms each time, and no source has been found. She has agreed enthusiastically to every investigation offered. A nurse cleaning her locker finds a syringe of brown fluid and an alcohol swab. She is afebrile and haemodynamically stable today. The resident wants to take the syringe to her straight away. Which one of the following should be done first?