INFECTIONS RELATED TO EXTERNAL VENTRICULA R DRAINAGE

Infection is the main complication of external ventricular drainage (E VD). This retrospective study assessed the relationships between EVD d uration, antibiotics and cerebrospinal fluid (CSF) infection. From Jan uary 1990 to December 1991, 53 neurosurgical patients, aged 7-76 years , a simplified acute physiological score (SAPS) of 1-20 and having a t otal of 64 EVD, were included in this study. CSF withdrawn from the dr ain was collected daily for bacteriological, biochemical and cytologic al analysis, until the EVD removal. CSF colonization was defined by a positive direct examination or a positive culture of CSF, in the absen ce of biochemical and cytological abnormalities. CSF drain infection w as defined by a low glucose concentration or leucocytosis without bloo d contamination. However the results of bacteriological analysis were modified by the antibiotics. The group of non infected patients and th e group of those with an infected or a colonized drain were comparable with regard to underlying neurosurgical diseases, age, SAPS, Glasgow coma scale and delay between hospital admission and day of drain inser tion and antibiotic administration. The EVD duration was significantly longer in infected EVD and colonized EVD. Staphylococci were the most frequently recognized bacteria and coagulase-negative staphylococci p redominated in CSF of colonized EVD. In five patients, antibiotics wer e unable to cure a meningitis. Their leucocyte count was increased. Th e glucose concentration was low, but the culture, remained negative. I t is concluded that duration and rate of EVD influence more the incide nce of infections than the systemic administration of antibiotics.