Impact of an external ventricular shunt (EVD) handling protocol on secondary meningitis rates: a historical cohort study with propensity score matching

Table 2 Patient demographics and EVD (external ventricular drain) catheter data for the entire cohort (n = 409)

	Pre-protocol n = 228	Post-protocol n = 181	p -value
Patient factors
Sex: Male (%)	50	44	0.31
Age (year; median [IQR])	60 [49–70	56 [47–66]	0.006
Emergency surgery (%)	95	86	< 0.001
Indication for EVD (%)			< 0.001
SAH/IVH	48	60
Tumor	10	12
Trauma	3	9
Other^a	39	19
Catheter factors
Surgeon			< 0.001
PGY 1–3	26	39
PGY 4–6	35	18
Neurosurgeon	39	43
Tunnelled EVD^b (%)	47	80	< 0.001
Operating time (min; median [IQR])	66 [54–80]	73 [58. 5–96]	0.005
Prophylactic antibiotics (%)	38	86	< 0.001
CSF leakage (%)	10	13	0.52
Frequency of CSF sampling (median ± IQR)	1 [1–3]	1 [1–2]	0.07
Duration of drainage (days; median ± IQR)	5.5 [2–12]	7 [3–12]	0.11

Shown are median values ± interquartile ranges (IQR). The percentage between brackets is the percentage of patients within that group. P-values represent the results of univariate analysis of the respective parameter. A p-value of < 0.05 was considered significant
CSF cerebral spinal fluid, EVD external ventricular drainage, IVH intraventricular hematoma, SAH subarachnoid hemorrhage, PGY post graduate year of the surgeon, Min minutes
^aincludes infratentorial intracerebral hematoma (38.4%), supratentorial intracerebral hematoma (23.3%), cerebellar infarction (17.8%), colloid cyst (5.5%), ventriculoperitoneal shunt malfunction (4.1%), and miscellaneous (11.0%)
^bthe remaining percentage received a Rickham reservoir

ISSN: 1471-2377