External ventricular drainage catheters: Effect of surface heparinization on bacterial colonization and infection

Surface heparinization of central venous catheters has earlier been shown t o reduce the frequency of bacterial colonization and septicaemia. The prese nt study was undertaken to investigate the benefit of surface heparinizatio n of external ventricular drainage (EVD) catheters in relation to bacterial colonization, as measured by bacterial growth and examination by a 16S-rRN A PCR assay, of catheters and of samples of cerebrospinal fluid (CSF). Nine ty-eight heparinized and one hundred unheparinized EVD catheters from the s ame batch of catheters were used. Twenty point five percent of the heparini zed and 22.8% (p = 0.63) of the unheparinized EVD catheters were colonized with bacteria. Culture of CSF, which is the definition of clinical infectio n in this study, yielded growth in 10.3% of patients with heparinized and i n 6.3% (p = 0.18) of those with unheparinized catheters. PCR examination yi elded positive signal in 31.3% of patients with heparinized catheters and i n 37.7% (p = 0.061) of patients without (CSF and catheters). In the subgrou p of patients with subarachnoid haemorrhages, there was a tendency, though not statistically significant, towards a lowered frequency of colonization with 23.1% for heparinized and 33.3% (p = 0.31) for unheparinized catheters . PCR examination did not contribute any further to the diagnostic procedur e in the patients concerned. The EVD catheters are skin-penetrating devices and contamination from the skin flora is common. Skin cultures, obtained a fter skin disinfection and insertion of catheters. showed growth of bacteri a in 62% of the patients.