This article is more than 5 years old. Information may no longer be current.
Prolonged antibiotic prophylaxis for external ventricular drains and increased risk for CDI
Click Here to Manage Email Alerts
The efficacy of antimicrobial prophylaxis is clearly established for patients who are undergoing neurosurgical procedures to prevent postoperative infections. Hospital-acquired infections do not occur often in these patients, but when infections do occur, they can have serious consequences and poor outcomes.
Postoperative infection risks
Risk factors for postoperative infections after neurosurgery include an American Society of Anesthesiologists (ASA) physical status classification of 2 or greater; postoperative monitoring of intracranial pressure or ventricular drains for 5 or more days; cerebrospinal fluid leak; procedure duration of more than 2 to 4 hours; diabetes; placement of a foreign body; repeat or additional neurosurgical procedures; concurrent or previous shunt infections; and finally, emergency procedures.
Neurosurgical patients who have an external ventricular drain (EVD) are often given antimicrobial prophylaxis before the operation, as well as postoperatively. American Society of Health-System Pharmacists clinical practice guidelines for prophylaxis in surgery states that there is a general lack of consensus on the use of antimicrobial prophylaxis in patients with EVDs. Typically in clinical practice, the postoperative prophylaxis is continued for the entire duration the drain is in place, which can be several days.
Jeff Brock
No consensus for treatment
The development of ventriculitis is the major concern because it can have significant morbidity and increased length of stay. Besides systemic antibiotic prophylaxis, insertion technique, wound care, use of antimicrobial-coated catheters and use of closed systems devices also have been associated with a reduction in infectious complications in these patients. Based on the available published evidence, the average infection rate related to EVDs is approximately 8% to 10%. In an international survey on prophylaxis recommendations with the use of EVDs, 43% to 64% of neurosurgery and neurocritical care specialists recommended post-procedural prophylaxis for the entire duration the device is in place, and only 4% to 10% recommended prophylaxis for 24 hours after EVD placement. While within the same survey, only 12% of infectious disease specialists recommended prophylaxis for the duration of the EVD. Results of this survey highlight the lack of consensus among specialty physicians.
In a retrospective single-center study of 308 patients who had an EVD in place for 3 or more days, patients were divided into two groups. One group received antimicrobial prophylaxis for the duration of the EVD (n=209), while the other group (n=99) received three or fewer doses of periprocedural prophylaxis. Of those in the extended group, the rate of ventriculitis was 3.8% compared with 4% in the short-term prophylaxis group, which was not statistically different.
Furthermore, in a recently published research article, researchers at Harborview Medical Center in Seattle observed an increase in incidence of Clostridium difficile infection among neurosurgical patients. They observed that of the 20 cases of CDI in this population, 19 of the cases were in those with an EVD. The researchers collaborated with the neurosurgery department to limit the duration of post-op prophylaxis to 24 hours instead of continuing for the entire duration the device was in place. No other changes in hospital policies or infection control practices occurred during the study period.
They then compared the baseline CDI rates for 2011 with those of 2012, when the change in practice occurred. The incidence of CDI decreased from 19 cases (1.97 per 1,000 patient-days) to five cases (0.51 per 1,000 patient-days) in the neurosurgical ICU and from 20 cases (1.18 per 1,000 patient-days) to 10 cases (0.55 per 1,000 patient-days) on the neurosurgical service. The incidence of hospital-wide CDI did not significantly change, with rates of 1.03 in 2011 and 0.91 in 2012.
The rate of positive cerebrospinal fluid cultures was similar before (12.8%) and after (10.3%) the protocol change.
Guideline update
As readers of Infectious Disease News already are aware, CDI increases the length of hospital stay, costs of treatment, morbidity and mortality of our patients. The guidelines to prevent CDIs in acute care hospitals were recently updated. These guidelines provide a comprehensive framework to aid clinicians in preventing this troublesome infection. The most common modifiable risk factors for preventing CDIs are decreasing antimicrobial use and preventing acquisition of C. difficile by adhering to good infection control principles and limiting patient exposure to the health care system. Limiting antimicrobial use is essential to any CDI prevention initiative. Encouraging appropriate antimicrobial use through antimicrobial stewardship programs has been associated with reduced CDI rates.
After discussing the use of prolonged antimicrobial prophylaxis in patients with EVDs with several neurosurgeons, it seems apparent that the culture of using antibiotics for extended periods of time for EVD prophylaxis is engrained in their training and that it would be very difficult to change this practice. For institutions that identify higher rates of CDI in this population, this newly published research regarding CDIs combined with evidence establishing no difference in the incidence of ventriculitis with prolonged prophylaxis may help persuade neurosurgery to decrease the duration of prophylaxis.
Additional study needed
However, a larger clinical trial establishing no difference in postoperative infection rates with short-course prophylaxis will be needed before the culture and guidelines of using prolonged prophylaxis among those with EVDs can be changed.
Bratzler DW. Am J Health Syst Pharm. 2013;70:195-283.
Dellit TH. Infect Control Hosp Epidemiol. 2014;35:589-590.
Dubberke ER. Infect Control Hosp Epidemiol. 2014;35:628-645.
McCarthy PJ. Neurocritical Care. 2010;12:220-224.
Disclosure: Brock reports no relevant financial disclosures.