Meropenem pharmacokinetics in cerebrospinal fluid: comparing intermittent and continuous infusion strategies in critically ill patients-a prospective cohort study.

Meropenem penetration into the cerebrospinal fluid (CSF) is subject to high interindividual variability resulting in uncertain target attainment in CSF. Recently, several authors recommended administering meropenem as a continuous infusion (CI) to optimize CSF exposure. This study aimed to compare the concentrations and pharmacokinetics of meropenem in CSF after intermittent infusion (II) and CI. This prospective, observational study (NCT04426383) included critically ill patients with external ventricular drains who received either II or CI of meropenem. Meropenem pharmacokinetics in plasma and CSF were characterized using population pharmacokinetic modeling (NONMEM 7.5). The developed model was used to compare the concentration-time profile and probability of target attainment (PTA) between II and CI. A total of 16 patients (8 CI, 8 II; samples: nplasma = 243, nCSF = 263) were recruited, with nine patients (5 CI, 4 II) suffering from cerebral and seven patients from extracerebral infections. A one-compartment model described the plasma concentrations adequately. Meropenem penetration into the CSF (partition coefficient (KP), cCSF/cplasma) was generally low (6.0%), exhibiting substantial between-subject variability (coefficient of variation: 84.0%). There was no correlation between the infusion mode and KP, but interleukin (IL)-6 measured in CSF showed a strong positive correlation with KP (P < 0.001). Dosing simulations revealed no relevant differences in CSF concentrations and PTA in CSF between CI and II. Our study did not demonstrate increased penetration rates or higher concentrations of meropenem in the CSF with CI compared with II. CLINICAL TRIALS: This study is registered with ClinicalTrials.gov as NCT04426383.

Purely Endoscopic Supracerebellar Infratentorial Approach to the Pineal Region in Pediatric Population.

Pineal lesions represent less than 1% of all brain tumors (Villani et al., Clin Neurol Neurosurg 109:1-6, 2007). The abysmal location and critical neurovascular structures remain a surgical challenge, despite the advent of microneurosurgery. The classical wide surgical suboccipital craniotomy with the supracerebellar infratentorial approach, described by Sir Victor Horsley (Victor, Proc R Soc Med 3:77-78, 1910), is infamous for its considerable surgical morbidity and mortality. This was later upgraded microneurosurgically by Stein to improve surgical outcomes (Stein, J Neurosurg 35:197-202, 1971).Ruge et al. reported the first purely endoscopic fenestration of quadrigeminal arachnoid cysts via this corridor (Ruge et al., Neurosurgery 38:830-7, 1996). A cadaver-based anatomical study by Cardia et al. demonstrated the viability for endoscope-assisted techniques (Cardia et al., J Neurosurg 2006;104(6 Suppl):409-14). However, the first purely endoscopic supracerebellar infratentorial (eSCIT) approach to a pineal cyst was performed in 2008 by Gore et al. (Gore PA et al., Neurosurgery 62:108-9, 2008).Unlike transventricular endoscopy, eSCIT approach poses no mechanical risk to the fornices and can be utilized irrespective of ventricular size. More vascular control and resultant reduction in uncontrolled hemorrhage improve the feasibility of attaining complete resection, especially around corners (Zaidi et al,, World Neurosurg 84, 2015). Gravity-dependent positioning and cerebrospinal fluid (CSF) diversion aid cerebellar relaxation, creating the ideal anatomical pathway. Also, angle of the straight sinus, tentorium, and tectal adherence can often influence the choice of approach; thus direct endoscopic visualization not only counteracts access to the engorged Galenic complex but also encourages sharp dissection of the arachnoid (Cardia et al., J Neurosurg 104:409-14, 2006). These tactics help provide excellent illumination with magnification, making it less fatiguing for the surgeon (Broggi et al., Neurosurgery 67:159-65, 2010).The purely endoscopic approach thwarts the dreaded risk of air embolisms, via simple copious irrigation from a small burr hole (Shahinian and Ra, J Neurol Surg B Skull Base 74:114-7, 2013). The tiny opening and closure are rapid to create, and the smaller wound decreases postoperative pain and morbidity. Recent literature supports its numerous advantages and favorable outcomes, making it a tough contender to traditional open methods.

Comparative study between ventriculosubgaleal shunt and external ventricular drain for management of post infective hydrocephalus among pediatrics.

PURPOSE: Post infective hydrocephalus (PIH) is a type of hydrocephalus which occurs after an infection of the brain or cerebrospinal fluid (CSF). Treatment of PIH requires temporary measures such as external ventricular drain (EVD) and ventriculosubgaleal shunt (VSGS) until CSF becomes clear and ready to implement VP shunt. Limited research has been done to explore the tradeoff between these approaches particularly in pediatric PIH patients. Our study compares the complications, mortality rates, and the cost of used resources of both procedures. METHODS: A prospective study was conducted for 18 months in which we compared between VSGS and EVD for management of PIH involving 42 randomized cases with 21 patients in group A operated by VSGS and 21 patients in group B operated by EVD. RESULTS: Our results show a statistically significant difference between both groups in the duration of implementation of VSGS/EVD until resolution of infection occurs. Additionally, a higher rate of pediatric intensive care unit (PICU) admission and a longer length of hospital stay (LOS) were recorded among the EVD group. No statistically significant difference between the number of complications that happened in both despite variations in their forms. Moreover, both groups showed nearly similar mortality rates. CONCLUSION: There is no significant difference in the rate of complications between VSGS and EVD for PIH. Based on that, VSGS emerges as a favorable and cost-effective option for the management of PIH which leads to less economic burden on patients and the country's health resources, especially in developing countries.

IMAGINER: improving accuracy with a mixed reality navigation system during placement of external ventricular drains. A feasibility study.

OBJECTIVE: The placement of a ventricular catheter, that is, an external ventricular drain (EVD), is a common and essential neurosurgical procedure. In addition, it is one of the first procedures performed by inexperienced neurosurgeons. With or without surgical experience, the placement of an EVD according to anatomical landmarks only can be difficult, with the potential risk for inaccurate catheter placement. Repeated corrections can lead to avoidable complications. The use of mixed reality could be a helpful guide and improve the accuracy of drain placement, especially in patients with acute pathology leading to the displacement of anatomical structures. Using a human cadaveric model in this feasibility study, the authors aimed to evaluate the accuracy of EVD placement by comparing two techniques: mixed reality and freehand placement. METHODS: Twenty medical students performed the EVD placement procedure with a Cushing's ventricular cannula on the right and left sides of the ventricular system. The cannula was placed according to landmarks on one side and with the assistance of mixed reality (Microsoft HoloLens 2) on the other side. With mixed reality, a planned trajectory was displayed in the field of view that guides the placement of the cannula. Subsequently, the actual position of the cannula was assessed with the help of a CT scan with a 1-mm slice thickness. The bony structure as well as the left and right cannula positions were registered to the CT scan with the planned target point before the placement procedure. CloudCompare software was applied for registration and evaluation of accuracy. RESULTS: EVD placement using mixed reality was easily performed by all medical students. The predefined target point (inside the lateral ventricle) was reached with both techniques. However, the scattering radius of the target point reached through the use of mixed reality (12 mm) was reduced by more than 54% compared with the puncture without mixed reality (26 mm), which represents a doubling of the puncture accuracy. CONCLUSIONS: This feasibility study specifically showed that the integration and use of mixed reality helps to achieve more than double the accuracy in the placement of ventricular catheters. Because of the easy availability of these new tools and their intuitive handling, we see great potential for mixed reality to improve accuracy.

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.

Predictors of shunt insertion in patients with aneurysmal subarachnoid haemorrhage-a single-centre retrospective analysis.

BACKGROUND: No standard has been established regarding timing and choice of strategy for discontinuation of external ventricular drainage (EVD) in patients with aneurysmal subarachnoid haemorrhage (aSAH), and little is known about the importance of clinical variables. A proportion of the patients who initially pass their discontinuation attempt return with delayed hydrocephalus and the need of a permanent shunt. Early differentiation between patients who need a shunt and those who do not would facilitate care. We conducted a retrospective analysis on patients with aSAH and an EVD to search significant differences in treatment and clinical variables between patients who received a permanent shunt during initial hospitalization or after readmission, and those who never received a shunt. METHODS: We included 183 patients with aSAH who received an EVD over a 4-year period between 2015 and 2018 and divided them into three groups: those who received a shunt during primary admission, those who were readmitted for delayed hydrocephalus and received a shunt, and those who never needed a shunt. Between these groups, we compared selected clinical variables as well as outcome at discharge and after 6 months. Additionally, we assessed the ability of a shunt dependency score (SDASH) to predict the need for permanent drainage in the patients. RESULTS: Of 183 included patients, 108 (59%) ultimately received a ventriculoperitoneal (VP) shunt. Of these, 89 (82%) failed discontinuation during the primary admission and received a permanent shunt before discharge from the neurosurgical department. The remaining 19 (18%) were discharged after successful discontinuation, but subsequently developed delayed hydrocephalus and were admitted for shunt placement a median of 39 (range: 18-235) days after ictus. Ninety-four patients were discharged after successful discontinuation of the EVD, consisting of those who never developed the need for a permanent shunt and the 19 who were readmitted with delayed hydrocephalus, corresponding to a 20% (19/94) readmittance rate. Clinical variables such as drainage volume or discontinuation strategy did not differ across the three groups of patients. The SDASH score failed to provide any clinically useful information regarding prediction of shunt placement. CONCLUSION: In this study, clinical variables including use of the predictive score SDASH predicted neither the overall need for nor the timing of shunt placement after aSAH. The homogeneous distribution of data between the three different groups renders strong independent clinical predictive factors unlikely. Thus, attempts to predict a permanent shunt requirement from these variables may be futile in these patients.

Detection and Management of Elevated Intracranial Pressure in the Treatment of Acute Community-Acquired Bacterial Meningitis: A Systematic Review.

Acute bacterial meningitis (ABM) is associated with severe morbidity and mortality. The most prevalent pathogens in community-acquired ABM are Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae. Other pathogens may affect specific patient groups, such as newborns, older patients, or immunocompromised patients. It is well established that ABM is associated with elevated intracranial pressure (ICP). However, the role of ICP monitoring and management in the treatment of ABM has been poorly described.An electronic search was performed in four electronic databases: PubMed, Web of Science, Embase, and the Cochrane Library. The search strategy chosen for this review used the following terms: Intracranial Pressure AND (management OR monitoring) AND bacterial meningitis. The search yielded a total of 403 studies, of which 18 were selected for inclusion. Eighteen studies were finally included in this review. Only one study was a randomized controlled trial. All studies employed invasive ICP monitoring techniques, whereas some also relied on assessment of ICP-based on clinical and/or radiological observations. The most commonly used invasive tools were external ventricular drains, which were used both to monitor and treat elevated ICP. Results from the included studies revealed a clear association between elevated ICP and mortality, and possibly improved outcomes when invasive ICP monitoring and management were used. Finally, the review highlights the absence of clear standardized protocols for the monitoring and management of ICP in patients with ABM. This review provides an insight into the role of invasive ICP monitoring and ICP-based management in the treatment of ABM. Despite weak evidence certainty, the present literature points toward enhanced patient outcomes in ABM with the use of treatment strategies aiming to normalize ICP using continuous invasive monitoring and cerebrospinal fluid diversion techniques. Continued research is needed to define when and how to employ these strategies to best improve outcomes in ABM.

Serial Diffusion Tensor Imaging and Rate of Ventricular Blood Clearance in Patients with Intraventricular Hemorrhage.

BACKGROUND: We developed a noninvasive biomarker to quantify the rate of ventricular blood clearance in patients with intracerebral hemorrhage and extension to the ventricles-intraventricular hemorrhage. METHODS: We performed magnetic resonance imaging in 26 patients at 1, 14, 28, and 42 days of onset and measured their hematoma volume (HV), ventricular blood volume (VBV), and two diffusion metrics: fractional anisotropy (FA), and mean diffusivity (MD). The ipasilesional ventricular cerebral spinal fluid's FA and MD were associated with VBV and stroke severity scores (National Institute of Health Stroke Scale [NIHSS]). A subcohort of 14 patients were treated with external ventricular drain (EVD). A generalized linear mixed model was applied for statistical analysis. RESULTS: At day 1, the average HVs and NIHSS scores were 14.6 ± 16.7 cm3 and 16 ± 8, respectively. A daily rate of 2.1% and 1.3% blood clearance/resolution were recorded in HV and VBV, respectively. Ipsilesional ventricular FA (vFA) and ventricular MD (vMD) were simultaneously decreased (vFA = 1.3% per day, posterior probability [PP] > 99%) and increased (vMD = 1.5% per day, PP > 99%), respectively. Patients with EVD exhibited a faster decline in vFA (1.5% vs. 1.1% per day) and an increase in vMD (1.8% vs. 1.5% per day) as compared with patients without EVD. Temporal change in vMD was associated with VBV; a 1.00-cm3 increase in VBV resulted in a 5.2% decrease in vMD (PP < 99%). VBV was strongly associated with NIHSS score (PP = 97-99%). A larger cerebral spinal fluid drained volume was associated with a greater decrease (PP = 83.4%) in vFA, whereas a smaller volume exhibited a greater increase (PP = 94.8%) in vMD. CONCLUSIONS: In conclusion, vFA and vMD may serve as biomarkers for VBV status.

Prompt closure versus gradual weaning of external ventricular drainage for hydrocephalus following aneurysmal subarachnoid haemorrhage: Protocol for the DRAIN randomised clinical trial.

BACKGROUND: Aneurysmal subarachnoid haemorrhage (aSAH) is a life-threatening disease caused by rupture of an intracranial aneurysm. A common complication following aSAH is hydrocephalus, for which placement of an external ventricular drain (EVD) is an important first-line treatment. Once the patient is clinically stable, the EVD is either removed or replaced by a ventriculoperitoneal shunt. The optimal strategy for cessation of EVD treatment is, however, unknown. Gradual weaning may increase the risk of EVD-related infection, whereas prompt closure carries a risk of acute hydrocephalus and redundant shunt implantations. We designed a randomised clinical trial comparing the two commonly used strategies for cessation of EVD treatment in patients with aSAH. METHODS: DRAIN is an international multi-centre randomised clinical trial with a parallel group design comparing gradual weaning versus prompt closure of EVD treatment in patients with aSAH. Participants are randomised to either gradual weaning which comprises a multi-step increase of resistance over days, or prompt closure of the EVD. The primary outcome is a composite outcome of VP-shunt implantation, all-cause mortality, or ventriculostomy-related infection. Secondary outcomes are serious adverse events excluding mortality, functional outcome (modified Rankin scale), health-related quality of life (EQ-5D) and Fatigue Severity Scale (FSS). Outcome assessment will be performed 6 months after ictus. Based on the sample size calculation (event proportion 80% in the gradual weaning group, relative risk reduction 20%, type I error 5%, power 80%), 122 patients are needed in each intervention group. Outcome assessment for the primary outcome, statistical analyses and conclusion drawing will be blinded. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT03948256.

External ventricular drainage in the management of pediatric patients with posterior fossa tumors and hydrocephalus: a retrospective cohort study.

PURPOSE: To determine whether intraoperative adjunctive EVD placement in patients with a posterior fossa tumor (PFT) led to improved surgical, radiographic, and clinical outcomes compared to those who did not receive an EVD. METHODS: Patients were grouped as those who underwent routine intraoperative adjunctive EVD insertion and those who did not at time of PFT resection. Patients who pre-operatively required a clinically indicated EVD insertion were excluded. Comparative analyses between both groups were conducted to evaluate clinical, radiological, and pathological outcomes. Odds ratios (ORs) with corresponding 95% confidence intervals (CIs) were computed for post-operative outcomes. RESULTS: Fifty-five selected patients were included, 15 who had an EVD placed at the time of PFT resection surgery, and 40 who did not. Children without an EVD did not experience a higher rate of complications or poorer post-operative outcomes compared to those with an EVD placed during resection surgery. There was no significant difference in the degree of gross total resection (p = 0.129), post-operative CSF leak (p = 1.000), and post-operative hemorrhage (p = 0.554) between those with an EVD and those without. The frequency of new cranial nerve deficits post-operatively was higher in those with an EVD (40%) compared to those without (3%, p = 0.001). There was a trend towards more frequently observed post-operative hydrocephalus in the EVD group (p = 0.057). CONCLUSION: The routine use of EVD as an intraoperative adjunct in clinically stable pediatric patients with posterior fossa tumors and hydrocephalus may not be associated with improved radiological or clinical outcomes.

Revisiting the transorbital approach for emergency external ventricular drainage: an anatomical study of relevant parameters and their effect on the effectiveness of using Tubbs' point.

The transorbital approach (TOA) can provide immediate access to the lateral ventricles by piercing the roof of the orbit (ROO) with a spinal needle and without the need of a drill. Reliable external landmarks for the TOA ventriculostomy have been described, however, the necessary spinal needle gauge and other relevant parameters such as the thickness of the ROO have not been evaluated. Nineteen formalin-fixed adult cadaveric heads underwent the TOA. Spinal needles of different gauges were consecutively used in each specimen beginning with the smallest gauge until the ROO was successfully pierced. The thickness of the ROO at the puncture site and around its margins was measured. Other parameters were also measured. The TOA was successfully performed in 14 cases (73.68%), where the most suitable needle gauge was 13 (47.37%), followed by a 10-gauge needle (36.84%). The mean thickness of the ROO at the puncture site, and the mean length of the needle to the puncture site were 1.7 mm (range 0.2-3.4 mm) and 15.5 mm (range 9.2-23.4 mm), respectively. A ROO thickness of greater than 2.0 mm required a 10-gauge needle in seven cases, and in five cases, a 10-gauge needle was not sufficient for piercing the ROO. The presence of hyperostosis frontalis interna (HFI) (21.05%) was related to the failure of this procedure (80%; p < 0.00). Using a 13/10-gauge spinal needle at Tubbs' point for TOA ventriculostomy allowed for external ventricular access in most adult specimens. The presence of HFI can hinder this procedure. These findings are important when TOA ventriculostomy is considered.

The insertion and management of an external ventricular drain in pediatric patients with hydrocephalus associated with medulloblastoma.

An external ventricular drain (EVD) is used to facilitate cerebrospinal fluid (CSF) removal in medulloblastoma patients suffering from hydrocephalus. It is essential to recognize that EVD management plays a crucial role in influencing the incidence of drain-related complications. However, the ideal method for EVD management remains undetermined. Our research sought to examine the safety of EVD placement and the impact of EVD on the incidences of intracranial infections, postresection hydrocephalus, and posterior fossa syndrome (PFS). We conducted a single-center observational study involving a cohort of 120 pediatric medulloblastoma patients who were treated from 2017 to 2020. The rates of intracranial infection, postresection hydrocephalus, and PFS were 9.2%, 18.3%, and 16.7%, respectively. EVD did not influence the occurrence of intracranial infection (p = 0.466), postresection hydrocephalus (p = 0.298), or PFS (p = 0.212). A gradual EVD weaning protocol correlated with an elevated incidence of postresection hydrocephalus (p = 0.033), whereas a rapid weaning approach resulted in 4.09 ± 0.44 fewer drainage days (p < 0.001) than the gradual weaning strategy. EVD placement (p = 0.010) and intracranial infection (p = 0.002) were linked to delayed speech return, whereas a longer duration of drainage was conducive to the recovery of language function (p = 0.010). EVD insertion was not correlated with the incidence of intracranial infection, postoperative hydrocephalus, or PFS. The optimal EVD management method should encompass a rapid EVD weaning strategy, followed by prompt drain closure. We have presented additional evidence to improve the safety of EVD insertion and management in neurosurgical patients to ultimately facilitate the establishment of standardized institutional/national implementation and management protocols.

Invasive Pressure Monitors: Leveling the Playing Field.

Invasive pressure monitors are ubiquitous in cardiothoracic and vascular anesthesia. This technology allows beat-to-beat assessment of central venous, pulmonary, and arterial blood pressures during surgery, procedural interventions, and critical care. Education is commonly focused on the procedural aspects and the complications associated with the initial placement of these monitors without instruction on the technical concepts required for obtaining accurate data. Anesthesiologists must understand the fundamental concepts on which measurements are made to effectively use invasive pressure monitors, including pulmonary artery catheters, central venous catheters, intra-arterial catheters, external ventricular drains, and spinal or lumbar drains. This review will address important gaps in knowledge surrounding leveling and zeroing of invasive pressure monitors, emphasizing the impact of varied practice patterns on patient care.

Iatrogenic lumbosacral infiltration with petroleum (hydrodesulfurized heavy) with secondary intrathecal distribution-a case report.

Petroleum is commonly used as a solvent, and primary intrathecal administration or secondary diffusion and subsequent clinical management has not been reported. We report the case of a male patient with intrathecal petroleum diffusion following accidental lumbar infiltration. After the onset of secondary myeloencephalopathy with coma and tetraparesis, continuous cranio-lumbar irrigation using an external ventricular and a lumbar drain was established. Cranial imaging revealed distinct supra- and infratentorial alterations. The patient improved slowly and was referred to rehabilitation. Intrathecal petroleum leads to myeloencephalopathy and continuous cranio-lumbar irrigation might be a safe treatment option.

The positive impact of cisternostomy with cisternal drainage on delayed hydrocephalus after aneurysmal subarachnoid hemorrhage.

BACKGROUND: Hydrocephalus is one of the major complications of aneurysmal subarachnoid haemorrhage (aSAH). In the acute setting, an external ventricular drain (EVD) is used for early management. A cisternal drain (CD) coupled with the micro-surgical opening of basal cisterns can be an alternative when the aneurysm is clipped. Chronic hydrocephalus after aSAH is managed with ventriculo-peritoneal (VP) shunt, a procedure associated with a wide range of complications. The aim of this study is to analyse the impact of micro-surgical opening of basal cisterns coupled with CD on the incidence of VP shunt, compared to patients treated with EVD. METHODS: The authors conducted a retrospective review of 89 consecutive cases of patients with aSAH treated surgically and endovascularly with either EVD or CD between January 2009 and September 2021. Patients were stratified into two groups: Group 1 included patients with EVD, Group 2 included patients with CD. Subgroup analysis with only patients treated surgically was also performed. We compared their baseline characteristics, clinical outcomes and shunting rates. RESULTS: There were no statistically significant differences between the two groups in terms of epidemiological characteristics, WFNS score, Fisher scale, presence of intraventricular hemorrhage (IVH), acute hydrocephalus, postoperative meningitis or of clinical outcomes at last follow-up. Cisternostomy with CD (Group 2) was associated with a statistically significant reduction in VP-shunt compared with the use of an EVD (Group 1) (9.09% vs 53.78%; p < 0.001). This finding was confirmed in our subgroup analysis, as among patients with a surgical clipping, the rate of VP shunt was 43.7% for the EVD group and 9.5% for the CD group (p = 0.02). CONCLUSIONS: Cisternostomy with CD may reduce the rate of shunt-dependent hydrocephalus. Cisternostomy allows the removal of subarachnoid blood, thereby reducing arachnoid inflammation and fibrosis. CD may enhance this effect, thus resulting in lower rates of chronic hydrocephalus.

Rapid Versus Gradual Weaning of External Ventricular Drain: A Systematic Literature Review and Meta-analysis.

The insertion of an external ventricular drain (EVD) is one of the most common neurosurgical procedures. Whether the weaning method (gradual or rapid) influences the ventriculoperitoneal shunt (VPS) insertion rate has not been conclusively established. The aim of this study is to provide a systematic literature review and conduct a meta-analysis of studies comparing gradual with rapid EVD weaning regarding VPS insertion rate. Articles were identified by searching the Pubmed/Medline, Embase, and Web of Science databases throughout October 2022. Two independent researchers assessed the studies for inclusion and quality. We included randomized trials, prospective cohort studies, and retrospective cohort studies, which compared gradual and rapid EVD weaning. The primary outcome was VPS insertion rate, whereas secondary outcomes were EVD-associated infection (EVDAI) rate and length of stay in the hospital and intensive care unit (ICU). Four studies directly comparing rapid versus gradual EVD weaning, with 1337 patients suffering from subarachnoid hemorrhage, were identified and included in the meta-analysis. VPS insertion rate was 28.1% and 32.1% in patients with gradual and rapid EVD weaning, respectively (relative risk 0.85, 95% confidence interval 0.49-1.46, p = 0.56). Further, the EVDAI rate was comparable between the groups (gradual group 11.2%, rapid group 11.5%, relative risk 0.67, 95% confidence interval 0.24-1.89, p = 0.45), whereas length of stay in the ICU and hospital were significantly shorter in the rapid weaning group (2.7 and 3.6 days, respectively; p < 0.01). Rapid EVD weaning seems comparable to gradual EVD weaning concerning VPS insertion rates and EVDAI, whereas hospital and ICU length of stay is significantly reduced.

Predictive Values for Time from Transducer Stopcock Closure to Accurate Intracranial Pressure Reading.

BACKGROUND: When using an external ventricular drain (EVD) to monitor intracranial pressure (ICP), nurses need to know how long to wait after each manipulation of the transducer before the displayed ICP value represents an accurate signal. This study explores ICP signal equilibration time (EqT) under clinical conditions. METHODS: This was a prospective ex vivo study using a simulated skull, standard EVD tubing, and a strain gauge transducer. All 270 trials simulating 90 combinations of different pressures and common clinical conditions were completed in August 2021. Each trial was recorded on video. Videos were scored using video editing software to obtain the exact start and stop time for each trial. RESULTS: The mean EqT was 44.90 (18.77) seconds. One hundred fifty (55.56%) observations did not reach their expected value within 60 s. The longest mean EqTs were noted when blood was present in the EVD tubing (57.67 [8.91] seconds), when air bubbles were in the tubing (57.41 [8.73] seconds), and when EVD tubing was not flat (level) (50.77 [15.43] seconds). An omnibus test comparing mean EqT for conditions with no variables manipulated (30.08 [16.07] seconds) against mean EqT for all others (47.18 [18.13] seconds) found that mean EqTs were significantly different (P < 0.001). CONCLUSIONS: Even when no additional variables were introduced, the mean EqTs were ~ 30 s. Common clinical variables increase the length of time before a transducer connected to an EVD will provide an accurate reading. Nurses should wait at least 30 s after turning the EVD stopcock before assuming ICP value reflects accurate ICP.

Use of α-Defensins to Help Diagnose Nosocomial Ventriculitis.

Ventriculitis is a severe complication of indwelling neurosurgical devices that is associated with significant morbidity and mortality. The incidence rate of ventriculitis is approximately 10% with external ventricular drains. Obstinately, patients with these indwelling neurosurgical devices are prone to have traditional cerebral spinal fluid parameters that lack sensitivity and specificity in diagnosing nosocomial ventriculitis. In addition, diagnosis can be arduous given that indolent pathogens are commonly implicated. Therefore, diagnosis is difficult but paramount to thwart the morbidity and mortality associated with this infectious condition as well as to reduce the prolonged use of broad-spectrum antibiotics. As we extrapolate from prosthetic joint infections, for which diagnosis can also be challenging, we learn that the use of α-defensins as a diagnostic biomarker for nosocomial ventriculitis may hold promise. Herein, the viewpoint of using α-defensins as a diagnostic biomarker for nosocomial ventriculitis is discussed.

Invasive Neuromonitoring Modalities in the Pediatric Population.

Invasive neuromonitoring has become an important part of pediatric neurocritical care, as neuromonitoring devices provide objective data that can guide patient management in real time. New modalities continue to emerge, allowing clinicians to integrate data that reflect different aspects of cerebral function to optimize patient management. Currently, available common invasive neuromonitoring devices that have been studied in the pediatric population include the intracranial pressure monitor, brain tissue oxygenation monitor, jugular venous oximetry, cerebral microdialysis, and thermal diffusion flowmetry. In this review, we describe these neuromonitoring technologies, including their mechanisms of function, indications for use, advantages and disadvantages, and efficacy, in pediatric neurocritical care settings with respect to patient outcomes.

Poor Accuracy of Manually Derived Head Computed Tomography Parameters in Predicting Intracranial Hypertension After Nontraumatic Intracranial Hemorrhage.

BACKGROUND: The utility of head computed tomography (CT) in predicting elevated intracranial pressure (ICP) is known to be limited in traumatic brain injury; however, few data exist in patients with spontaneous intracranial hemorrhage. METHODS: We conducted a retrospective review of prospectively collected data in patients with nontraumatic intracranial hemorrhage (subarachnoid hemorrhage [SAH] or intraparenchymal hemorrhage [IPH]) who underwent external ventricular drain (EVD) placement. Head CT scans performed immediately prior to EVD placement were quantitatively reviewed for features suggestive of elevated ICP, including temporal horn diameter, bicaudate index, basal cistern effacement, midline shift, and global cerebral edema. The modified Fisher score (mFS), intraventricular hemorrhage score, and IPH volume were also measured, as applicable. We calculated the accuracy, positive predictive value (PPV), and negative predictive value (NPV) of these radiographic features for the coprimary outcomes of elevated ICP (> 20 mm Hg) at the time of EVD placement and at any time during the hospital stay. Multivariable backward stepwise logistic regression analysis was performed to identify significant radiographic factors associated with elevated ICP. RESULTS: Of 608 patients with intracranial hemorrhages enrolled during the study time frame, 243 (40%) received an EVD and 165 (n = 107 SAH, n = 58 IPH) had a preplacement head CT scan available for rating. Elevated opening pressure and elevated ICP during hospitalization were recorded in 48 of 152 (29%) and 103 of 165 (62%), respectively. The presence of ≥ 1 radiographic feature had only 32% accuracy for identifying elevated opening pressure (PPV 30%, NPV 58%, area under the curve [AUC] 0.537, 95% asymptotic confidence interval [CI] 0.436-0.637, P = 0.466) and 59% accuracy for predicting elevated ICP during hospitalization (PPV 63%, NPV 40%, AUC 0.514, 95% asymptotic CI 0.391-0.638, P = 0.820). There was no significant association between the number of radiographic features and ICP elevation. Head CT scans without any features suggestive of elevated ICP occurred in 25 of 165 (15%) patients. However, 10 of 25 (40%) of these patients had elevated opening pressure, and 15 of 25 (60%) had elevated ICP during their hospital stay. In multivariable models, mFS (adjusted odds ratio [aOR] 1.36, 95% CI 1.10-1.68) and global cerebral edema (aOR 2.93, 95% CI 1.27-6.75) were significantly associated with elevated ICP; however, their accuracies were only 69% and 60%, respectively. All other individual radiographic features had accuracies between 38 and 58% for identifying intracranial hypertension. CONCLUSIONS: More than 50% of patients with spontaneous intracranial hemorrhage without radiographic features suggestive of elevated ICP actually had ICP > 20 mm Hg during EVD placement or their hospital stay. Morphological head CT findings were only 32% and 59% accurate in identifying elevated opening pressure and ICP elevation during hospitalization, respectively.