Will clinical parameters reliably predict external ventricular drain-associated ventriculitis: Is frequent routine cerebrospinal fluid surveillance necessary?

The accuracy and safety of intraoperative ultrasound-guided external ventricular drainage in intraventricular hemorrhage

Severe IVH often results in a poor outcome. Currently, EVD is a standard treatment for IVH, but there is little research to show whether using ultrasound to guide the catheter placement improves outcome. Patients with severe IVH who had iUS-guided EVD (the iUS-guided group) were enrolled retrospectively and compared with a group who had EVD performed without ultrasound guidance (the control group) from January 2016 to July 2022. Data were collected on accuracy of the catheter placement, complications and outcome at 3 months assessed by mRS. The accuracy of the EVD placement was classified as optimal placement, sub-optimal placement and misplacement according to the position of the catheter tip. The complications reported are catheter-related hemorrhage, intracranial infection and hydrocephalus. There were 105 cases enrolled, with 72 patients in the iUS-guided group having 131 catheters inserted and 33 patients in the group where ultrasound was not used with a total of 59 catheters. 116 (88.55%) were optimally placed, 12 (9.16%) sub-optimal and 3 (2.29%) misplaced in the iUS-guided group, while 25 (42.37%) were in optimally placed, 30 (50.85%) sub-optimal and 4(6.78%) misplaced in the control group. Accuracy of placement was highly significantly improved using ultrasound (P < 0.001). The operation time and the average catheterized time were longer in the iUS-guided group (P < 0.05), but the complication rates were no different between the groups. The mRS at three months was not significantly different between the two groups. Using iUS to place EVD catheters in patients with severe IVH is a safe technique delivering more accurate catheter placement without increasing the complication rate compared with freehand placement.

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.

Risk Factors Promoting External Ventricular Drain Infections in Adult Neurosurgical Patients at the Intensive Care Unit-A Retrospective Study

Objectives: Multiple risk factors have been described to be related to external ventricular drain (EVD) associated infections, with results varying between studies. Former studies were limited by a non-uniform definition of EVD associated infection, thus complicating a comparison between studies. In this regard, we assessed risk factors promoting EVD associated infections and propose a modified practice-oriented definition of EVD associated infections.

Methods: We performed a retrospective, single-center study on patients who were treated with an EVD, at the neurosurgical intensive care unit (ICU) at a tertiary center between 2008 and 2019. Based on microbiological findings and laboratory results, patients were assigned into an infection and a non-infection group. Patient characteristics and potential risk factors were compared between the two groups (p < 0.05). Receiver operating characteristics (ROC) for significant clinical, serum laboratory and cerebrospinal fluid (CSF) parameters were calculated.

Results: In total, 396 patients treated with an EVD were included into the study with a mean age of 54.3 (range: 18–89) years. EVD associated infections were observed in 32 (8.1%) patients. EVD insertion at another hospital (OR 3.86), and an increased CSF sampling frequency of more than every third day (OR 12.91) were detected as major risk factors for an EVD associated infection. The indication for EVD insertion, surgeon's experience, the setting of EVD insertion (ICU vs. operating room) and the operating time did not show any significant differences between the two groups. Furthermore, ROC analysis showed that clinical, serum laboratory and CSF parameters did not provide specific prediction of EVD associated infections (specificity 44.4%). This explains the high overtreatment rate in our cohort with the majority of our patients who received intrathecal vancomycin (63.3%), having either negative microbiological results (n = 12) or were defined as contaminations (n = 7).

Conclusions: Since clinical parameters and blood analyzes are not very predictive to detect EVD associated infections in neurosurgical patients, sequential but not too frequent microbiological and laboratory analysis of CSF are still necessary. Furthermore, we propose a uniform classification for EVD associated infections to allow comparability between studies and to sensitize the treating physician in determining the right treatment.

Cerebrospinal Fluid Collected by Lumbar Puncture Has a Higher Diagnostic Accuracy than Collected by Ventriculostomy

BACKGROUND

Patients harboring an external ventricular drain (EVD) who develop signs of infection require screening for infection in the central nervous system (CNS). The cerebrospinal fluid (CSF) can be collected by the EVD or by lumbar puncture (LP). If only one sample is analyzed, the diagnosis might be dubious or false-negative. The objective of this study was to compare the diagnosis accuracy of CNS infection of CSF samples collected from EVD and LP.

METHODS

We conducted a transversal study where data were prospectively collected from 2016 to 2019. Patients harboring EVD with signs of infection were submitted to the CSF analysis collected by LP and EVD. Diagnosis sensibility and results correlation were analyzed using the kappa index.

RESULTS

The 141 samples from LP and 141 samples from EVD were collected from 108 patients. Among the 282 samples, a total of 77 had infection. Seventy CSF samples from LP fulfilled infection criteria. However, only 32 EVD samples demonstrated infection. Among the 70 cases of infection based on the LP sample, 25 CSF samples collected from the EVD were also suggestive of infection; but in 45 patients only the CSF samples from LP met infection criteria. Seven patients had diagnosis of infection only in the EVD sample. The kappa correlation index of the results obtained from LP and EVD was 0.260 and the McNemar χ² test was <0.01.

CONCLUSIONS

The CSF analysis exclusive from the EVD has a low sensibility and negative predictive value. CSF collected from LP has a sensibility 2.18 times higher than EVD.

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.

Safety and Efficacy of Transcatheter Administration of Tissue Plasminogen Activating Factor as Adjuvant Therapy for Intraventricular Hemorrhage

Objective

Stroke is the fifth leading cause of death in the United States and the leading cause of disability. Hemorrhagic stroke has higher risks of mortality and neurologic deficit. Higher still, acute intraventricular hemorrhage (IVH) has mortality between 50% and 80% while complicating subarachnoid hemorrhage in 15% of cases and intracerebral hemorrhage in 40% of cases. We sought to demonstrate that early adjuvant intraventricular recombinant tissue plasminogen activating factor (rt-PA) improved outcomes.

Methods

Retrospective chart review was performed on patients aged 18-95 years with external ventricular drain (EVD) and intraventricular rt-PA for clot evacuation in IVH between 2005 and 2015. In total, 22 patients met the inclusion criteria. Generalized linear modeling was performed with factorial analysis using the Glasgow Coma Score (GCS) on arrival, GCS at EVD placement, EVD day of onset of rt-PA administration, GCS at onset of rt-PA administration, total duration of EVD, necessity of ventriculoperitoneal (VP) shunt, occurrence of ventriculitis, day of ventriculitis, GCS after rt-PA, length of stay (LOS) in the intensive care unit (ICU), and hospital disposition.

Results

Presenting GCS affected LOS significantly. Ventriculitis only significantly affected ICU LOS. GCS after rt-PA only significantly affected discharge GCS. EVD day of rt-PA protocol commencement demonstrated significant effects on EVD duration and cerebrospinal fluid (CSF) diversion requirement. Age affected ICU and hospital LOS.

Conclusion

These findings argue for larger prospective trials of EVD day two rt-PA protocol inception in acute IVH. Reported ventriculitis rates with EVDs are 8.8%, while we demonstrated a rate of 18% without significant effects except in ICU LOS. Transcatheter intraventricular rt-PA is safe and effective as an adjuvant in acute spontaneous intraventricular hemorrhage with the greatest benefit of rt-PA protocol at EVD day two.

Peripheral white blood cell count as a screening tool for ventriculostomy-related infections

One of the most common complications following external ventricular drain (EVD) placement is infection. Routine cultures of cerebrospinal fluid (CSF) are often used to screen for infection, however several days may pass before infection is discovered. In this study, we compared the predictive value of daily recorded vital sign parameters and peripheral white blood count (WBC) in identifying ventriculostomy-related infections. Patients with EVDs who had CSF cultures for microorganisms performed between January 2011 and July 2017 were assigned to either an infected and/or uninfected study group. Clinical parameters were then compared using t-test, chi squared and multiple logistic regression analyses. Patients of any age and gender were included. One hundred seventy uninfected and 10 infected subjects were included in the study. Nine of the 10 infected patients had an elevated WBC (>10.4 × 10³/μL), with a significantly greater WBC (15.9 × 10³/μL) than the uninfected group (10.4 × 10³/μL) (p-value ≤ 0.0001). Using logistic regression, we found no association between patient vital signs and CSF infection except for WBC (p = .003). As a diagnostic marker for CSF infection, the sensitivity and specificity of WBC elevation greater than 15 × 10³/μL was 70% (7/10) and 90.2% (147/163), respectively. This study serves as a 'proof of concept' that WBC could be useful as potential screening tool for early detection of CSF infection post-EVD placement. Future investigation using a large, multicenter prospective study is needed to further assess the applicability of this parameter.

Effect of sample processing and time delay on cell count and chemistry tests in cerebrospinal fluid collected from drainage systems

Introduction

Cerebrospinal fluid (CSF) from extra-ventricular drainage (EVD) systems is routinely analysed to diagnose EVD–related bacterial meningitis. We investigated the effect of time delay and sample processing on cell count and basic biochemistry results in EVD CSF to define optimal turnaround time and whether manual and automated cell counting are comparable in such samples.

Materials and methods

In total, 32 EVD CSF samples were analysed. Baseline testing included cell counting (Fuchs-Rosenthal chamber and Sysmex XE5000) and biochemistry analyses (glucose, lactate, proteins). Manual cell counting was also performed at intervals of 61-90 and 91-150 minutes from baseline in the residual sample. Biochemistry analyses were performed in samples before and after centrifugation at baseline and at 91-150 minutes interval.

Results

At 91-150 minutes total cell count (P < 0.001), large lymphocytes (P = 0.007), neutrophils (P < 0.001) and phagocytes (P = 0.006) obtained by manual counting decreased and the number of disintegrated cells count increased (P = 0.016) compared to the baseline values. Considering method comparison, proportional difference between methods for all cell (sub)groups was obtained, whereas polymorphonuclears also showed the constant difference (y = 11.21 + 1.22x). Compared to centrifuged CSF, lower concentration of glucose and lactates were obtained in uncentrifuged samples (P < 0.001) at baseline.

Conclusions

Manual cell counting should be performed within 60 minutes as any delay can alter results. The same counting technique should be used to obtain longitudinally assessable results. Biochemistry tests are stable in uncentrifuged CSF up to 2.5 hours.