Relationship of causative organism and time to infection among children with cerebrospinal fluid shunt infection

Preoperative nomogram predicting ventriculoperitoneal shunt longevity after initial shunt failure

Background and objectives

Initial shunt failure following ventriculoperitoneal (VP) shunt surgery has a significant impact on the working time of the shunt. However, there are few studies regarding factors affecting VP shunt longevity. Hence, in this study, we aimed to build a nomogram to predict the longevity of the replacement VP shunt in patients with initial shunt failure.

Methods

From 2011 to 2021, 142 patients with initial VP failure who underwent VP shunt revision were enrolled and relevant clinical and demographic factors were analyzed. Univariate and multivariate Cox proportional hazard regression models were used to choose predictors, and a nomogram was constructed using nine independent prognostic variables: sex, age, hydrocephalus type, intensive care unit admission, tracheostomy, decompressive craniectomy, craniotomy, lumbar cisterna drainage, and ventricular drainage. The prediction models' discrimination, accuracy, calibration, and clinical value were evaluated using Harrell's C-index, a calibration plot, and decision curve analysis.

Results

At 1 month, 3 months, and 5 years, the nomogram's C-index was 0.680, 0.708, and 0.694, respectively. The nomogram's calibration plot provided a good fit for the overall prediction over the course of 1 year. Decision curve analysis predicted that 1-3 months after surgery will yield good net benefits between 30 and 50% probability thresholds.

Conclusion

A preoperative nomogram may be an effective tool for assessing VP shunt longevity after initial VP shunt placement.

Cerebrospinal fluid shunt infections in children

Cerebrospinal fluid (CSF) shunts are commonly used for the long-term management of hydrocephalus in children. Shunt infection remains a common complication, occurring in about 5%-15% of CSF shunts. This narrative review summarises key evidence from recent literature on the epidemiology, pathogenesis, clinical presentation, diagnosis, management, outcomes and prevention of CSF shunt infections in children. The majority of shunt infections occur due to contamination at the time of surgery, with coagulase-negative staphylococci and Staphylococcus aureus being the most common infecting organisms. Clinical presentations of shunt infection can be varied and difficult to recognise. CSF cultures are the primary test used for diagnosis. Other CSF and blood parameters may aid in diagnosis but lack sensitivity and specificity. Core aspects of management of shunt infections include systemic antimicrobial therapy and surgical removal of the shunt. However, many specific treatment recommendations are limited by a lack of robust evidence from large studies or controlled trials. Shunt infections may result in long hospital stays, worsening hydrocephalus, neurological sequelae and other complications, as well as death. Therefore, reducing the incidence of infection and optimising management are high priorities. Antibiotic prophylaxis at the time of shunt placement, improved surgical protocols and antibiotic-impregnated shunts are key strategies to prevent shunt infections. Nevertheless, further work is needed to identify additional strategies to prevent complications and improve outcomes.

Cerebrospinal Fluid Shunt Infections in Children: Do Hematologic and Cerebrospinal Fluid White Cells Examinations Correlate With the Type of Infection?

BACKGROUND

Cerebrospinal fluid (CSF) shunt infections in children represent an increasing problem in clinical practice. However, comprehensive clinical, laboratory and microbiologic data are scarce in pediatric age.

METHODS

We conducted a 10-year retrospective study to (1) analyze clinical, laboratory and microbiologic parameters associated with infections in children; (2) analyze results according to the type of catheter (medicated or not), type of infection (first or relapses), type of hydrocephalus (acquired and congenital), presence or not of bacteriemia; (3) describe antibiotic susceptibilities and their evolution during the study period.

RESULTS

Eighty-seven children with shunt infection and 61 children with mechanical shunt malfunction were enrolled. Fever, vomit, leukocytosis and elevated C-reactive protein were more frequent in the infected group (P < 0.001), while neurologic symptoms developed more frequently in the noninfected group (10.3% vs. 27.87%; P = 0.006). Local signs of inflammation and abdomen distension were similarly reported in the 2 groups. Children with medicated shunts had lower cell count in the CSF (12/mm3) compared with those with nonmedicated shunts (380/mm3; P < 0.0001). Gram-negative bacteria were more common in the not-medicated catheters (90.91% vs. 50% of cultures; P = 0.04). Gram-negative bacteria were identified in 50.67% of CSF cultures, Gram-positive bacteria in 53.33% and fungi were observed in 5.33%. Sixteen children (18.4%) had also a positive blood culture. Enterococci isolation was associated with relapsed infections (37.50% vs. 15.25%; P = 0.05).

CONCLUSIONS

Our study shows that the diagnosis and management of children with shunt infections are challenging. Prospective studies with a comprehensive approach focusing on patient, medical, microbiologic and surgical risk factors for first infection are urgently needed.

The Hydrocephalus Clinical Research Network quality improvement initiative: the role of antibiotic-impregnated catheters and vancomycin wound irrigation

OBJECTIVE

Two previous Hydrocephalus Clinical Research Network (HCRN) studies have demonstrated that compliance with a standardized CSF shunt infection protocol reduces shunt infections. In this third iteration, a simplified protocol consisting of 5 steps was implemented. This analysis provides an updated evaluation of protocol compliance and evaluates modifiable shunt infection risk factors.

METHODS

The new simplified protocol was implemented at HCRN centers on November 1, 2016, for all shunt procedures, excluding external ventricular drains, ventricular reservoirs, and subgaleal shunts. Procedures performed through December 31, 2019, were included (38 months). Compliance with the protocol, use of antibiotic-impregnated catheters (AICs), and other variables of interest were collected at the index operation. Outcome events for a minimum of 6 months postoperatively were recorded. The definition of infection was unchanged from the authors' previous report.

RESULTS

A total of 4913 procedures were performed at 13 HCRN centers. The overall infection rate was 5.1%. Surgeons were compliant with all 5 steps of the protocol in 79.4% of procedures. The infection rate for the protocol alone was 8.1% and dropped to 4.9% when AICs were added. Multivariate analysis identified having ≥ 2 complex chronic conditions (odds ratio [OR] 1.76, 95% confidence interval [CI] 1.26-2.44, p = 0.01) and a history of prior shunt surgery within 12 weeks (OR 1.84, 95% CI 1.37-2.47, p < 0.01) as independent risk factors for shunt infection. The use of AICs (OR 0.70, 95% CI 0.50-0.97, p = 0.05) and vancomycin irrigation (OR 0.36, 95% CI 0.21-0.62, p < 0.01) were identified as independent factors protective against shunt infection.

CONCLUSIONS

The authors report the third iteration of their quality improvement protocol to reduce the risk of shunt infection. Compliance with the protocol was high. These updated data suggest that the incorporation of AICs is an important, modifiable infection prevention measure. Vancomycin irrigation was also identified as a protective factor but requires further study to better understand its role in preventing shunt infection.

Antimicrobial use in central nervous system infections

PURPOSE OF REVIEW

Central nervous system (CNS) infections are associated with high rates of morbidity and mortality. The purpose of this review is to summarize current antimicrobial therapies, as well as, updates in the management of community-acquired meningitis and healthcare-associated meningitis and ventriculitis.

RECENT FINDINGS

Due to the increasing rates of multidrug resistant and extensively-drug resistant organisms, available antimicrobials are limited. Novel treatment options include newer systemic antimicrobials and antimicrobials that have previously limited data in the management of CNS infections. Although limited by retrospective data, intrathecal (IT) and intraventricular (IVT) routes of administration offer the opportunity for antimicrobials that conventionally have minimal cerebrospinal fluid (CSF) penetration to achieve high CSF concentrations while minimizing systemic exposure.

SUMMARY

Updates in the use of systemic, IT, and IVT antimicrobials offer promise as therapeutic options for CNS infections. Additional pharmacokinetic and prospective data are needed to confirm these findings.