Modalities and accuracy of diagnosis of external ventricular drainage-related infections: a prospective multicentre observational cohort study

Development of an Evidence-based Care Bundle for Prevention of External Ventricular Drain-related Infection: Results of a Single-center Prospective Cohort Study and Literature Review

Background

External ventricular drain (EVD)-related infection (ERI) is a common complication in cranial neurosurgery practice with high mortality. The risk factors associated with ERI are not well studied in low- and middle-income countries (LMIC) like India. Identifying the risk variables is a necessity to design robust evidence-based care bundles for ERI prevention.

Materials and methods

This is a single-center prospective cohort study. Patients with and without ERI during the 2-year study period were analyzed along with literature review to identify the risk variables associated with ERI. The Institute for Healthcare Improvement (IHI) comprehensive flowchart was used to develop the concept care bundle for ERI prevention.

Results

A total of 211 EVD were inserted during the study period. 15 ERI (7.1%) were identified based on IDSA criteria, with an average infection rate of 11.12 per 1000 EVD days. Gram negative bacteria (GNB) were the predominant pathogen (12/15, 80%), with Klebsiella pneumoniae (6/15, 40%) being the most common bacteria isolated. In multivariate analysis, the risk variables associated with ERI were use of broad spectrum pre-surgical antimicrobial prophylaxis for long duration, choice of posterior craniometric points for EVD insertion, EVD duration >7 days, EVD leak and surveillance cerebrospinal fluid (CSF) sampling at periodic intervals. Based on the risk variables identified in this study and literature review, a consensus decision on the care elements for the insertion and maintenance phases was chosen for the concept care bundle for ERI prevention.

Conclusion

An evidence-based concept care bundle for ERI prevention is proposed for further multicentric evaluation and validation.

How to cite this article

Ponnambath DK, Divakar G, Mamachan J, Biju S, Raja K, Abraham M. Development of an Evidence-based Care Bundle for Prevention of External Ventricular Drain-related Infection: Results of a Single-center Prospective Cohort Study and Literature Review. Indian J Crit Care Med 2024;28(8):760-768.

Treatment of wound infections linked to neurosurgical implants

As neurosurgery has advanced technologically, more and more neurosurgical implants are being employed on an aging patient population with several comorbidities. As a result, there is a steady increase in the frequency of infections linked to neurosurgical implants, which causes serious morbidity and mortality as well as abnormalities of the skull and inadequate brain protection. We discuss infections linked to internal and external ventricular and lumbar cerebrospinal fluid drainages, neurostimulators, craniotomies, and cranioplasty in this article. Biofilms, which are challenging to remove, are involved in all implant-associated illnesses. It takes a small quantity of microorganisms to create a biofilm on the implant surface. Skin flora bacteria are implicated in the majority of illnesses. Microorganisms that cause disruptions in wound healing make their way to the implant either during or right after surgery. In about two thirds of patients, implant-associated infections manifest early (within the first month after surgery), whereas the remaining infections present later as a result of low-grade infections or by direct extension from adjacent infections (per continuitatem) to the implants due to soft tissue damage. Except for ventriculo-atrial cerebrospinal fluid shunts, neurosurgical implants are rarely infected by the haematogenous route. This research examines established and clinically validated principles that are applicable to a range of surgical specialties using implants to treat biofilm-associated infections in orthopaedic and trauma cases. Nevertheless, there is little evidence and no evaluation in sizable patient populations to support the success of this extrapolation to neurosurgical patients. An optimal microbiological diagnostic, which includes sonicating removed implants and extending culture incubation times, is necessary for a positive result. Additionally, a strategy combining surgical and antibiotic therapy is needed. Surgical procedures involve a suitable debridement along with implant replacement or exchange, contingent on the biofilm's age and the state of the soft tissue. A protracted biofilm-active therapy is a component of antimicrobial treatment, usually lasting 4-12 weeks. This idea is appealing because it allows implants to be changed or kept in place for a single surgical procedure in a subset of patients. This not only enhances quality of life but also lowers morbidity because each additional neurosurgical procedure increases the risk of secondary complications like intracerebral bleeding or ischemia.

Risk Factors for External Ventricular Drainage-Related Infection: A Systematic Review and Meta-analysis

Background and Objectives

External ventricular drainage (EVD) is one of the most commonly performed neurosurgical procedures, but EVD-related infection constitutes a significant health concern. Yet, little consensus identifies the risk factors for the development of EVD-related infection. Therefore, we performed a meta-analysis to systematically summarize existing evidence on the incidence and risk factors for EVD-related infection.

Methods

PubMed, Embase, and the Cochrane Library databases from database inception to February 28, 2022, were searched for all studies investigating the incidence and risk factors for EVD-related infection. Data were assessed by R-4.2.0 software. The meta-analysis was used to calculate pooled odds ratios (OR) and 95% confidence intervals (CI).

Results

A total of 48 studies were included. Among the 29 factors analyzed, statistically significant risk factors were subarachnoid hemorrhage(SAH)/intraventricular hemorrhage(IVH) (OR = 1.48, 95% CI = 1.20-1.82, p < 0.001), concomitant systemic infection (OR = 1.90, 95% CI = 1.34-2.70, p < 0.001), other neurosurgical procedures (OR = 1.76, 95% CI = 1.02-3.04, p = 0.041), change of catheter (OR = 5.05, 95% CI = 3.67-6.96, p < 0.001), bilateral EVDs (OR = 2.25, 95% CI = 1.03-4.89, p = 0.041), (cerebrospinal fluid) CSF leak (OR = 3.19, 95% CI = 2.12-4.81, p < 0.001) and duration of EVD >7 days (OR = 4.62, 95% CI = 2.26-9.43, p < 0.001). The use of silver-coated catheters (OR = 0.57, 95% CI = 0.38-0.87, p = 0.008) and antibiotic-impregnated catheters (OR = 0.60, 95% CI = 0.41-0.88, p = 0.009) might help reduce the risk of infection. No significant difference was indicated in studies evaluating factors like diabetes mellitus (OR = 1.25, 95% CI = 0.90-1.75, p = 0.178), steroids used (OR = 1.52, 95% CI = 0.96-2.4, p = 0.074), prophylactic antibiotics(OR = 0.87, 95% CI = 0.66-1.14, p = 0.308).

Discussion

The meta-analysis of various relevant factors in the onset of EVD-related infection in patients submitted to EVD enabled us to establish a more probable profile of the patients who are more likely to develop it during the treatment.

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.

Longitudinal ventricular cerebrospinal fluid profile in patients with spontaneous subarachnoid hemorrhage

Background

Spontaneous subarachnoid hemorrhage (SAH) is a severe neurological disease that frequently requires placement of external ventricular drainage (EVD). Cerebrospinal fluid (CSF) obtained via the drain is used to detect potential complications of SAH.

Objective

This study aimed to describe the longitudinal profile of routine CSF parameters in patients with SAH and to identify associations with neurological complications.

Methods

A total of thirty-three patients with spontaneous SAH who required an EVD and had at least three consecutive CSF samples collected over a period of more than 7 days were included in this study.

Results

A median of 6 longitudinally collected CSF samples per patient were available within 1–22 days after SAH onset. Overall, red blood cells (RBC) steadily decreased over time, whereas white blood cells (WBC) and total protein (TP) increased until days 6 and 13, respectively, and decreased thereafter. The estimated decay rates of RBC, WBC, and TP were 28, 22, and 6% per day. Distinct CSF patterns over time were linked to known complications after SAH. Patients with rebleeding showed increased RBC, TP, and phagocytosing cells compared to patients without re-bleeding. For ventriculitis, an elevated cell index with a higher proportion of granulocytes was characteristic. CSF of patients with delayed cerebral ischemia showed increased RBC and WBC compared to patients without DCI. Early CSF WBC and cell index were predictive for the occurrence of DCI and ventriculitis later during the disease course. The amount of daily CSF drainage via EVD had no impact on routine CSF parameters.

Conclusion

Longitudinal CSF characteristics are associated with SAH-related complications.

A nationwide prospective multicenter study of external ventricular drainage: accuracy, safety, and related complications

OBJECTIVE

External ventricular drainage (EVD) catheters are associated with complications such as EVD catheter infection (ECI), intracranial hemorrhage (ICH), and suboptimal placement. The aim of this study was to investigate the rates of EVD catheter complications and their associated risk factor profiles in order to optimize the safety and accuracy of catheter insertion.

METHODS

A total of 348 patients with urgently placed EVD catheters were included as a part of a prospective multicenter observational cohort. Strict definitions were applied for each complication category.

RESULTS

The rates of misplacement, ECI/ventriculitis, and ICH were 38.6%, 12.2%, and 9.2%, respectively. Catheter misplacement was associated with midline shift (p = 0.002), operator experience (p = 0.031), and intracranial length (p < 0.001). Although mostly asymptomatic, ICH occurred more often in patients receiving prophylactic low-molecular-weight heparin (LMWH) (p = 0.002) and those who required catheter replacement (p = 0.026). Infectious complications (ECI/ventriculitis and suspected ECI) occurred more commonly in patients whose catheters were inserted at the bedside (p = 0.004) and those with smaller incisions (≤ 1 cm) (p < 0.001). ECI/ventriculitis was not associated with preinsertion antibiotic prophylaxis (p = 0.421), catheter replacement (p = 0.118), and catheter tunneling length (p = 0.782).

CONCLUSIONS

EVD-associated complications are common. These results suggest that the operating room setting can help reduce the risk of infection, but not the use of preoperative antibiotic prophylaxis. Although EVD-related ICH was associated with LMWH prophylaxis for deep vein thrombosis, there were no significant clinical manifestations in the majority of patients. Catheter misplacement was associated with operator level of training and midline shift. Information from this multicenter prospective cohort can be utilized to increase the safety profile of this common neurosurgical procedure.

Meningitis and encephalitis management in the ICU

PURPOSE OF REVIEW

Management of patients with meningitis and encephalitis oftentimes requires ICU level of care. This article is an update on management for meningitis and encephalitis with focus on clinical care in the ICU. Information provided is based on a review of recent studies with focus on studies since 2017.

RECENT FINDINGS

Advances in diagnostic and treatment approach for different pathogens are presented. Nosocomial meningitis now constitutes a major part of brain infections seen in ICUs in the developed world. Advances in ICU care of central nervous system (CNS) infections include application of newer diagnostic methods, improved understanding and delivery of antibiotics to the CNS, infection prevention for nosocomial infections, and application of neuromonitoring where indicated.

SUMMARY

Advances in diagnostics and therapeutic approach to CNS infections are continually made. For intensivists, focus on neuromonitoring and brain resuscitation in critically ill patients with CNS infections may present a path to enhance preservation of brain function and improve outcomes. VIDEO ABSTRACT: http://links.lww.com/COCC/A22.

A Retrospective Quality Analysis of External Ventricular Drain Infection Rates Following Stroke Diagnoses and Other Brain Injuries: Comparison of Emergency Room and ICU/OR Setting

Objective

The purpose of this study was to analyze the incidence of infections in patients following placement of External Ventricular Drain (EVD) in either the Emergency Room (ER) or the Intensive Care Unit (ICU)/ Operating Room (OR) at a single Comprehensive Stroke Center.

Methods

Retrospective analysis of post-procedure infection rates in 710 patients with EVDs placed on site between 2010 and 2018 was performed. We analyzed cases between sex, age, stroke and non-stroke related and further requirement of conversion of the EVD to a ventriculoperitoneal (VP) shunt.

Results

Significant decrease in EVD related infection (ERIs) rates following the shift in EVD placement from ER to ICU/OR (from 13% to 7.7%, p=.03) among all ages, sex and type of brain injury was observed. Furthermore, our data also shows that the rate of conversion of EVDs to VP shunts is independent of the setting where EVD was placed, but increases in patients who develop ERIs. 23.1% of stroke patients that developed an ERI required a conversion to VP shunt while 67.3% of non-stroke patients that developed an ERI required further VP shunt (p<.001) showing that non-stroke EVD patients with infections are more likely to require VP shunt.

Conclusion

This is one of the larger retrospective studies conducted on EVD related infections. ERIs were significantly higher when EVDs were placed in the ER. Moreover, our results highlight the relation between ERIs and further requirement of conversion EVD to VP shunt. These figures highlight the importance of focusing on infection rates, and the implications CSF infection has on the long-term care of patients.

Factors and measures predicting external CSF drain-associated ventriculitis

Objective

To determine the diagnostic value of clinical factors and biochemical or microbiological measures for diagnosing a drain-associated ventriculitis, we summarized the available evidence.

Methods

We performed a systematic review and meta-analysis of studies of patients with external ventricular CSF drains who developed drain-associated ventriculitis by searching MEDLINE, EMBASE, and CENTRAL electronic database. We reported the occurrence of abnormal test results in patients with and without drain-associated ventriculitis. For continuous variables, we recalculated mean values presented in multiple studies.

Results

We identified 42 articles published between 1984 and 2018 including 3,035 patients with external CSF drains of whom 697 (23%) developed drain-associated bacterial ventriculitis. Indications for drain placement were subarachnoid, intraventricular or cerebral hemorrhage or hemorrhage not further specified (69%), traumatic brain injury (13%), and obstructive hydrocephalus secondary to a brain tumor (10%). Fever was present in 116 of 162 patients with ventriculitis (72%) compared with 80 of 275 (29%) patients without ventriculitis. The CSF cell count was increased for 74 of 80 patients (93%) with bacterial ventriculitis and 30 of 95 patients (32%) without ventriculitis. CSF culture was positive in 125 of 156 episodes classified as ventriculitis (80%), and CSF Gram stain was positive in 44 of 81 patients (54%). In patients with ventriculitis, PCR on ribosomal RNA was positive on 54 of 78 CSF samples (69%).

Conclusion

Clinical factors and biochemical and microbiological measures have limited diagnostic value in differentiating between ventriculitis and sterile inflammation in patients with external CSF drains. Prospective well-designed diagnostic accuracy studies in drain-associated ventriculitis are needed.