Fig. 1.

Diagram showing the HCRN shunt surgery protocol. In the step requiring the surgeon to ask for antibiotics, the surgeon requests that intravenous cefazolin (30 mg/kg) be given before making the first incision. In patients allergic to cephalosporins, vancomycin (15 mg/kg) is used. When the patient’s hair is clipped, the hair is removed using clippers in the region of the incision as per the surgeon’s usual practice. The shunt equipment selected for shunt insertion or revision is selected by the surgeon, except that antibiotic-impregnated shunts were not allowed. After the shunt procedure and prior to closure, 1 ml (10 mg/ml) of vancomycin mixed with 2 ml (2 mg/ml) of gentamicin is injected into the shunt reservoir with a 25-gauge needle (or smaller). In patients with a prior adverse reaction to vancomycin, the gentamicin is given alone. For this study, procedures in which vancomycin was not used were counted as noncompliant.