Effectiveness of a Chlorhexidine Dressing on Silver-coated External Ventricular Drain-associated Colonization and Infection: A Prospective Single-blinded Randomized Controlled Clinical Trial

Effectiveness of a multimodal strategy to reduce external ventricular drain-associated infection: A quasi-experimental study

BACKGROUND

Infection is a serious complication in neurosurgical patients who undergo external ventricular drain (EVD) insertion.

METHODS

We conducted a quasi-experimental study in patients who underwent EVD insertion to evaluate the impact of a multi-modal strategy to reduce the incidence of external ventricular drain associated infections (EVDAIs). The study was divided into 2 periods; (1) the pre-intervention period when techniques for EVD insertion and maintenance were up to the discretion of the neurosurgeons and (2) the post-intervention after implementation of a multi-modal strategy (cefazolin antibiotic prophylaxis, preoperative chlorhexidine showers, application of postoperative chlorhexidine-impregnated dressing, limited manipulation of the EVD, and meticulous EVD management). The primary outcome was the incidence rate of EVDAIs; secondary outcomes included in-hospital mortality rate, the hospital length of stay.

RESULTS

In total, 135 patients were included. The incidence rate of EVDAIs was significantly reduced in the post-intervention period (5.6 cases/1,000 EVD-days) compared with the pre-intervention period (18.2 cases/1,000 EVD-days; P=0.026). There were no differences in all secondary outcomes analyzed. This multi-modal strategy was associated with high satisfaction among health care personnel.

CONCLUSIONS

Implementation of a multi-modal strategy was associated with a reduction in the incidence of EVDAIs. This was in line with our goal of promoting a new culture of safety despite being in a resource-limited setting.

Management of external ventricular drain: to wean or not to wean?

PURPOSE

External ventricular drain (EVD) is one of the most frequent procedures in neurosurgery and around 15 to 30% of these patients require a permanent cerebrospinal fluid (CSF) diversion. The optimal EVD weaning strategy is still unclear. Whether gradual weaning compared to rapid closure, reduces the rate of permanent CSF diversion remains controversial. The aim of this trial is to compare the rates of permanent CSF diversion between gradual weaning and rapid closure of an EVD.

METHODS

This was a single-center, retrospective cohort study including patients between 2010 to 2020. Patients were divided into a weaning (WG) and non-weaning (NWG) group. The primary outcome was permanent CSF diversion rates, secondary outcomes included hospitalization time, EVD-related morbidity, and clinical outcome.

RESULTS

Out of 412 patients, 123 (29.9%) patients were excluded due to early death or palliative treatment. We registered 178 (61.6%) patients in the WG and 111 (38.4%) in the NWG. Baseline characteristics were comparable between groups. The VPS rate was comparable in both groups (NWG 37.8%; WG 39.9%, p = 0.728). EVD related infection (13.5% vs 1.8%, p < 0.001), as well as non-EVD related infection rates (2.8% vs 0%, p < 0.001), were significantly higher in the WG. Hospitalization time was significantly shorter in the NWG (WG 24.93 ± 9.50 days; NWG 23.66 ± 14.51 days, p = 0.039).

CONCLUSION

Gradual EVD weaning does not seem to reduce the need for permanent CSF diversion, while infection rates and hospitalization time were significantly higher/longer. Therefore, direct closure should be considered in the clinical setting.

Postprocedural Complications of External Ventricular Drains: A Meta-Analysis Evaluating the Absolute Risk of Hemorrhages, Infections, and Revisions

BACKGROUND

External ventricular drain (EVD) insertion is often a lifesaving procedure frequently used in neurosurgical emergencies. It is routinely done at the bedside in the neurocritical care unit or in the emergency room. However, there are infectious and noninfectious complications associated with this procedure. This meta-analysis sought to evaluate the absolute risk associated with EVD hemorrhages, infections, and revisions. The secondary purpose was to identify and characterize risk factors for EVD complications.

METHODS

We searched the MEDLINE (PubMed) database for "external ventricular drain," "external ventricular drain" + "complications" or "Hemorrhage" or "Infection" or "Revision" irrespective of publication year. Estimates from individual studies were combined using a random effects model, and 95% confidence intervals (CIs) were calculated with maximum likelihood specification. To investigate heterogeneity, the t2 and I2 tests were utilized. To evaluate for publication bias, a funnel plot was developed.

RESULTS

There were 260 total studies screened from our PubMed literature database search, with 176 studies selected for full-text review, and all of these 176 studies were included in the meta-analysis as they met the inclusion criteria. A total of 132,128 EVD insertions were reported, with a total of 130,609 participants having at least one EVD inserted. The pooled absolute risk (risk difference) and percentage of the total variability due to true heterogeneity (I2) for hemorrhagic complication was 1236/10,203 (risk difference: -0.63; 95% CI: -0.66 to -0.60; I2: 97.8%), infectious complication was 7278/125,909 (risk difference: -0.65; 95% CI: -0.67 to -0.64; I2: 99.7%), and EVD revision was 674/4416 (risk difference: -0.58; 95% CI: -0.65 to -0.51; I2: 98.5%). On funnel plot analysis, we had a variety of symmetrical plots, and asymmetrical plots, suggesting no bias in larger studies, and the lack of positive effects/methodological quality in smaller studies.

CONCLUSIONS

In conclusion, these findings provide valuable information regarding the safety of one of the most important and most common neurosurgical procedures, EVD insertion. Implementing best-practice standards is recommended in order to reduce EVD-related complications. There is a need for more in-depth research into the independent risk factors associated with these complications, as well as confirmation of these findings by well-structured prospective studies.

Current Perspectives on the Diagnosis and Management of Healthcare-Associated Ventriculitis and Meningitis

Ventriculitis or post-neurosurgical meningitis or healthcare-associated ventriculitis and meningitis (VM) is a severe infection that complicates central nervous system operations or is related to the use of neurosurgical devices or drainage catheters. It can further deteriorate patients who have already presented significant neurologic injury and is associated with high morbidity, mortality, and poor functional outcome. VM can be difficult to distinguish from aseptic meningitis, inflammation that follows hemorrhagic strokes and neurosurgical operations. The associated microorganisms can be either skin flora or nosocomial pathogens, most commonly, Gram-negative bacteria. Classical microbiology can fail to isolate the culprit pathogen. Novel cerebrospinal fluid (CSF) biomarkers and molecular microbiology can fill the diagnostic gap and expedite pathogen identification and treatment. The pathogens may demonstrate significant resistant patterns and their antibiotic treatment can be difficult, as many important drug classes, including the beta-lactams and the glycopeptides, hardly penetrate to the CSF, and do not achieve therapeutic levels at the site of the infection. Treatment modifications, such as higher daily dose and prolonged or continuous administration, might increase antibiotic levels in the site of infection and facilitate pathogens clearance. However, in the case of therapeutic failure or infection due to difficult-to-treat bacteria, the direct antibiotic instillation into the CSF, in addition to the intravenous antibiotic delivery, may help in the resolution of infection. However, intraventricular antibiotic therapy may result in aseptic meningitis and seizures, concerning the administration of aminoglycosides, polymyxins, and vancomycin. Meanwhile, bacteria form biofilms on the catheter or the device that should routinely be removed. Novel neurosurgical treatment modalities comprise endoscopic evacuation of debris and irrigation of the ventricles. VM prevention includes perioperative antibiotics, antimicrobial impregnated catheters, and the implementation of standardized protocols, regarding catheter insertion and manipulation.

Challenges in the Microbiological Diagnosis of Implant-Associated Infections: A Summary of the Current Knowledge

Implant-associated infections are characterized by microbial biofilm formation on implant surface, which renders the microbiological diagnosis challenging and requires, in the majority of cases, a complete device removal along with a prolonged antimicrobial therapy. Traditional cultures have shown unsatisfactory sensitivity and a significant advance in the field has been represented by both the application of the sonication technique for the detachment of live bacteria from biofilm and the implementation of metabolic and molecular assays. However, despite the recent progresses in the microbiological diagnosis have considerably reduced the rate of culture-negative infections, still their reported incidence is not negligible. Overall, several culture- and non-culture based methods have been developed for diagnosis optimization, which mostly relies on pre-operative and intra-operative (i.e., removed implants and surrounding tissues) samples. This review outlines the principal culture- and non-culture based methods for the diagnosis of the causative agents of implant-associated infections and gives an overview on their application in the clinical practice. Furthermore, advantages and disadvantages of each method are described.

Effect of External Ventricular Drain Tunnel Length on Cerebrospinal Fluid Infection Rates-A Bayesian Network Meta-Analysis

BACKGROUND

External ventricular drain (EVD)-associated cerebrospinal fluid infection (EACI) remains a major complication associated with EVD. Length of EVD tunnel, an overlooked but modifiable factor, can be associated with increased risk of EACI. The aim of this study is to find the tunnel length associated with least chances of EACI by performing a network meta-analysis.

METHODS

A comprehensive search of different databases was performed to retrieve studies that studied the rates of EACI with different EVD tunnel lengths and a Bayesian network meta-analysis was performed.

RESULTS

Six studies met the inclusion criteria and were included in the network meta-analysis. With 0 cm tunnel length as reference, the odds ratio (OR) for developing EACI was minimum for tunnel length 5-10 cm (OR, 0.027). It was followed by tunnel length of 5 cm (OR, 0.060) and 10 cm (OR, 0.075). The surface under the cumulative ranking curve plot showed that the probability of the tunnel length 5-10 cm (ranked first), 5 cm (ranked second), and 10 cm (ranked third) for being the best EVD tunnel length was found to be 86%, 64%, and 61%, respectively.

CONCLUSIONS

The length for which an EVD is tunneled may have an impact on the rate of EACI. Our network meta-analyses showed that the tunnel length of 5-10 cm was associated with the lowest rates of EACI, with 86% probability of being the best EVD tunnel length. The probability of a patient with 5-10 cm EVD length developing EACI was 2.7% compared with zero tunnel length.

Chlorhexidine dressings could reduce external ventricular drain infections: results from a systematic review and meta-analysis

BACKGROUND

The incidence of external ventricular drain (EVD) infections remains high. Chlorhexidine dressings have demonstrated efficacy in reducing infections associated with indwelling catheters at other body sites, although evidence for their use with EVDs is limited.

AIM

The aim of this systematic review and meta-analysis was to evaluate the efficacy of chlorhexidine dressings in reducing EVD associated cerebrospinal fluid infection (EVDAI).

METHODS

Systematic review and meta-analysis. MEDLINE, EMBASE and the Cochrane library were queried for articles from inception. The primary outcome was the incidence of EVDAI. Secondary outcomes included device safety, microbiological outcomes and shunt-dependency.

FINDINGS

From 896 unique records, 5 studies were included of which 4 presented suitable data for quantitative analysis including 3 case series and one underpowered randomised controlled trial. There was a high risk of bias in all studies. 880 patients were included with a mean age of 57.7 years (95% CI 57.4-58.0 years). In primary outcome analysis, the chlorhexidine dressing group had a significantly lower incidence of EVDAI (1.7% vs. 7.9%, RD = 0.07, 95% CI 0.00 - 0.13, p = 0.04).

CONCLUSION

Chlorhexidine dressings may reduce the incidence of EVDAI but require future study in randomised trials to definitively determine efficacy.

Early permanent cerebrospinal fluid diversion in aneurysmal subarachnoid hemorrhage: does a lower rate of nosocomial meningitis outweigh the risk of delayed cerebral vasospasm related morbidity?

Objective: Early permanent cerebrospinal fluid (CSF) diversion for hydrocephalus during the first 2 weeks after aneurysmal subarachnoid hemorrhage (aSAH) shortens the duration of external ventricular drainage (EVD) and reduces EVD-associated infections (EVDAI). The objective of this study was to detect any association with symptomatic delayed cerebral vasospasm (DCVS), or delayed cerebral ischemia (DCI) by the time of hospital discharge. Methods: We used a single-center dataset of aSAH patients who had received a permanent CSF diversion. We compared an 'early group' in which the procedure was performed up to 14 days after the ictus, to a 'late group' in which it was performed from the 15^th day onward. Results: Among 274 consecutive aSAH patients, 39 (14%) had a permanent CSF diversion procedure with a silver-coated EVD. While the blood clot burden was similarly distributed, patients with early permanent CSF diversion (20 out of 39; 51%) had higher levels of consciousness on admission. Early permanent CSF diversion was associated with less colonized catheter, a shorter duration of extracorporeal CSF diversion (OR 0.73, 95%CI 0.58-0.92 per EVD day), and a lower rate of EVDAI (OR 0.08, 95%CI 0.01-0.80). The occurrence of CSF diversion device obstruction, the rate of symptomatic DCVS or detected DCI on computed tomography and the likelihood of a poor outcome at discharge did not differ between the two groups. Discussion: Early permanent CSF diversion lowers the occurrence of catheter colonization and infectious complication without affecting DCVS-related morbidity in good-grade aSAH patients. These findings need confirmation in larger prospective multicenter cohorts. Abbreviations: aSAH: aneurysmal subarachnoid hemorrhage; BNI: Barrow Neurological Institute Scale; CSF: Cerebrospinal fluid; DCVS: Delayed Cerebral Vasospasm; DCI: Delayed Cortical Ischemia; EKNZ: Ethik-Kommission Nordwest Schweiz; EVD: External ventricular drain; EVDAI: External ventricular drain-associated infections; GCS: Glasgow Coma Scale; IRB: Institutional Review Board; IVH: Inraventricular hemorrhage; mRS: Modified Rankin Scale; SOS: Swiss Study of Subarachnoid Hemorrhage Registry; WFNS: World Federation Neurological-Surgeon Scale.

Use of Focused Ultrasound (Sonication) for the Diagnosis of Infections in Neurosurgical Operations: A Systematic Review and Meta-Analysis

OBJECTIVE

Postoperative infections are one of the most devastating complications in neurosurgery, and their results are even more disastrous when biocompatible implants are involved. As the application of these implants increases, the need for a sensitive and efficient method to detect pathogens becomes imperative. The application of sonication appears to be a viable option.

METHODS

A systematic review and meta-analysis of the available literature was conducted, looking for studies reporting findings from the application of sonication following neurosurgical operations. To be included, an article needed to contain information about the material that was subjected to sonication, indication of other culture methods that were applied, and information about the isolated pathogens.

RESULTS

Six studies comprising 437 patients were included in the meta-analysis. Potential superiority of sonication over conventional microbiologic methods was found in the detection of gram-positive bacteria and in particular of coagulase-negative Staphylococcus species. A sensitivity of 0.87 and a specificity of 0.57 were calculated.

CONCLUSIONS

Regardless of the potential of sonication, it is still not a panacea. Additional studies are expected to provide significant insight into the indications and limitations of this technique.

Randomized Controlled Trial to Reduce Bacterial Colonization of Surgical Drains with the Use of Chlorhexidine-Coated Dressings After Breast Cancer Surgery

BACKGROUND

Breast surgery is considered a clean surgery. However, surgical-site infection (SSI) rates are currently higher than predicted. Postoperative drains remain in situ for several days, with inevitable bacterial colonization and increased SSI risk.

METHODS

This randomized controlled trial from October 2016 to January 2018 analyzed patients undergoing breast cancer surgery. The patients were randomized to either the standard drain care group or the antiseptic dressing group (3M® Tegaderm® CHG). Drain samples taken on postoperative days (PODs) 7 and 14 were cultured as standardized in the laboratory. Colonization rates and SSI were compared between the two groups.

RESULTS

The study enrolled 104 patients with 167 surgical drains. The patients' clinical characteristics were similar in the two groups, with no statistically significant differences. Bulb fluid cultures at postoperative week (POW) 1 were positive for 42.9% of the control group and 28.9% of the antiseptic group (p = 0.06). Cultures from the POW 2 assessment were positive for 79.7% of the control group versus 54.9% of the antiseptic group (p = 0.001). Cultures from drain tubes were positive for 79.8% of the control group and 50.7% of the antiseptic group (p = < 0.001). In 11 patients, an SSI developed, 3 (5.8%) from the intervention and 8 (15.4%) from the control procedure (p = 0.11).

CONCLUSION

The study findings demonstrated that the use of antiseptics at the drain exit site significantly reduced bacterial colonization of the closed drainage system in breast cancer surgery. Semi-permeable occlusive chlorhexidine-impregnated dressings provide an opportunity to test simple, safe, and low-cost interventions that may reduce drain bacterial colonization and SSI after breast surgery.

Comparative efficacy of 13 antimicrobial dressings and different securement devices in reducing catheter-related bloodstream infections: A Bayesian network meta-analysis

PURPOSE

The purpose of our study is to carry out a Bayesian network meta-analysis comparing the efficacy of different antimicrobial dressings for prevention of catheter-related blood infections (CRBSI) and rank these antimicrobial dressings for practical consideration.

METHODS

We searched the PubMed, Cochrane library, Embase, earlier relevant meta-analysis and reference lists of included studies for randomized controlled trials (RCTs) that compared dressings for prevention of CRBSI. Two authors independently extracted data from each included RCT according to a predesigned Excel spreadsheet and assessed the methodological quality of included RCTs using the Cochrane risk of bias tool. Data was analyzed using the WinBUGS (V.1.4.3) and the Stata (V.15.0).

RESULTS

Finally, 35 RCTs involving 8494 patients and evaluating 13 dressings were included. Network meta-analysis showed that transparent dressing may be the best way to prevent CRBSI. Suture and bordered polyurethane dressing might have the lowest risk of CRBSI rate per 1000 catheter-days, and sutureless securement device might lead to the lowest incidence of catheter failure.

CONCLUSIONS

This network meta-analysis indicated that transparent dressings may be selected for the prevention of CRBSI in patients with central venous catheters, which is of importance in future research. Although evidence is scant, more attention should be paid to head-to-head comparisons of the most commonly used dressings in this field.