Fluid management of the neurological patient: a concise review

Group-Based Trajectory Modeling of Fluid Balance in Elderly Patients with Acute Ischemic Stroke: Analysis from Multicenter ICUs

INTRODUCTION

Acute ischemic stroke (AIS) significantly contributes to severe disability and mortality among the elderly. This study aims to explore the association between longitudinal fluid balance (FB) trajectories and clinical outcomes in elderly patients with AIS. Our hypothesis posits the existence of multiple latent trajectories of FB in patients with AIS during the initial 7 days following ICU admission.

METHODS

Patients (age ≥ 65 years) with AIS and continuous FB records were identified from two large databases. Group-based trajectory modeling identified latent groups with similar 7-day FB trajectories. Subsequently, multivariable logistic and quasi-Poisson regression were employed to evaluate the relationship between trajectory groups and outcomes. Additionally, nonlinear associations between maximum fluid overload (FO) and outcomes were analyzed using restricted cubic spline models. To further validate our findings, subgroup and sensitivity analysis were conducted.

RESULTS

A total of 1146 eligible patients were included in this study, revealing three trajectory patterns were identified: low FB (84.8%), decreasing FB (7.2%), and high FB (7.9%). High FB emerged as an independent risk factor for in-hospital mortality. Compared with those without FO, patients with FO had a 1.57-fold increased risk of hospital mortality (adjusted odd ratio (OR) 1.57, 95% confidence interval (CI) 1.08-2.27), 2.37-fold increased risk of adverse kidney event (adjusted OR 2.37, 95% CI 1.56-3.59), and 1.33-fold increased risk of prolonged ICU stay (adjusted incidence rate ratio (IRR) 1.33, 95% CI 1.19-1.48). The risk of hospital mortality and adverse kidney event increased linearly with rising maximum FO (P for non-linearity = 0.263 and 0.563, respectively).

CONCLUSION

Daily FB trajectories were associated with adverse outcomes in elderly patients with AIS. Regular assessment of daily fluid status and restriction of FO are crucial for the recovery of critically ill patients.

Sodium and Its Impact on Outcome After Aneurysmal Subarachnoid Hemorrhage in Patients With and Without Delayed Cerebral Ischemia

OBJECTIVES

To perform a detailed examination of sodium levels, hyponatremia and sodium fluctuations, and their association with delayed cerebral ischemia (DCI) and poor outcome after aneurysmal subarachnoid hemorrhage (aSAH).

DESIGN

An observational cohort study from a prospective SAH Registry.

SETTING

Tertiary referral center focused on SAH treatment in the Amsterdam metropolitan area.

PATIENTS

A total of 964 adult patients with confirmed aSAH were included between 2011 and 2021.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A total of 277 (29%) developed DCI. Hyponatremia occurred significantly more often in DCI patients compared with no-DCI patients (77% vs. 48%). Sodium levels, hyponatremia, hypernatremia, and sodium fluctuations did not predict DCI. However, higher sodium levels were significantly associated with poor outcome in DCI patients (DCI onset -7, DCI +0, +1, +2, +4, +5, +8, +9 d), and in no-DCI patients (postbleed day 6-10 and 12-14). Also, hypernatremia and greater sodium fluctuations were significantly associated with poor outcome in both DCI and no-DCI patients.

CONCLUSIONS

Sodium levels, hyponatremia, and sodium fluctuations were not associated with the occurrence of DCI. However, higher sodium levels, hypernatremia, and greater sodium fluctuations were associated with poor outcome after aSAH irrespective of the presence of DCI. Therefore, sodium levels, even with mild changes in levels, warrant close attention.

Nursing Interventions to Prevent Secondary Injury in Critically Ill Patients with Traumatic Brain Injury: A Scoping Review

Background: Traumatic brain injury is a prevalent health issue with significant social and economic impacts. Nursing interventions are crucial in preventing secondary injury and improving patient prognosis. This scoping seeks to map and analyze the existing scientific evidence on nursing interventions aimed at preventing secondary injuries in critically ill patients with traumatic brain injury. Methods: The review was conducted according to Arksey and O'Malley's methodological framework. The electronic databases Pubmed, MEDLINE Complete, CINAHL Complete, Nursing & Allied Health Collection: Comprehensive, Cochrane Central Register of Controlled Trials, and Cochrane Clinical Answers were consulted in May 2023. We included articles published in English and Portuguese between 2010 and 2023. Results: From the initial search, 277 articles were identified, with 15 meeting the inclusion criteria for the review. Nursing interventions for TBI patients include neuromonitoring, therapeutics, analytical surveillance, professional training, and family support. Nurses play a crucial role in detecting neurological changes, administering treatments, monitoring metabolic markers, training staff, and involving families. These interventions aim to prevent secondary injury and improve patient outcomes. Conclusions: By prioritizing evidence-based practice and utilizing innovative technologies, nurses enhance TBI patient care and contribute to overall well-being.

Measuring pulsatile cortical blood flow and volume during carotid endarterectomy

Carotid endarterectomy (CEA) involves removal of plaque in the carotid artery to reduce the risk of stroke and improve cerebral perfusion. This study aimed to investigate the utility of assessing pulsatile blood volume and flow during CEA. Using a combined near-infrared spectroscopy/diffuse correlation spectroscopy instrument, pulsatile hemodynamics were assessed in 12 patients undergoing CEA. Alterations to pulsatile amplitude, pulse transit time, and beat morphology were observed in measurements ipsilateral to the surgical side. The additional information provided through analysis of pulsatile hemodynamic signals has the potential to enable the discovery of non-invasive biomarkers related to cortical perfusion.

Adult Cerebral Malaria: Acute and Subacute Imaging Findings, Long-term Clinical Consequences

Cerebral malaria is an important cause of mortality and neurodisability in endemic regions. We show magnetic resonance imaging (MRI) features suggestive of cytotoxic and vasogenic cerebral edema followed by microhemorrhages in 2 adult UK cases, comparing them with an Indian cohort. Long-term follow-up images correlate ongoing changes with residual functional impairment.

Fluid therapy in the acute brain injured patient

Adequate fluid therapy in the acute brain injured (ABI) patient is essential for maintaining an adequate brain and systemic physiology and preventing intra- and extracranial complications. The target of euvolemia, implying avoidance of both hypovolemia and fluid overloading (or "hypervolemia," by definition associated with fluid extravasation leading to tissue edema) is of key importance. Primary brain injury can be aggravated by secondary brain injury and systemic deterioration through diverse pathways which can challenge appropriate fluid management, e.g. neuroendocrine and electrolyte disorders, stress cardiomyopathy (also known as cardiac stunning) and neurogenic pulmonary edema. This is an updated expert opinion aiming to provide a practical overview on fluid therapy in the ABI patient, partly based on more recent work and stressing the fact that intravenous fluids should be regarded as drugs, with their inherent potential for both benefit and (unintended) harm.

Pulse Pressure Variance (PPV)-Guided Fluid Management in Adult Patients Undergoing Supratentorial Tumor Surgeries: A Randomized Controlled Trial

Objective  Appropriate fluid management in neurosurgery is critical due to the risk of secondary brain injury. Determination of volume status is challenging with static variables being unreliable. Goal-directed fluid therapy with dynamic variables allows reliable determination of fluid responsiveness and promises better outcomes. We aimed to compare the intraoperative fluid requirement between conventional central venous pressure (CVP)-guided and pulse pressure variance (PPV)-guided fluid management in supratentorial tumor surgeries. Materials and Methods  This prospective, randomized, double-blind, single-center trial was conducted with 72 adults undergoing supratentorial tumor surgery in a supine position. Patients were divided into two groups of 36 patients each receiving CVP- and PPV-guided fluid therapy. The CVP-guided group received boluses to target CVP greater than 8 mm Hg along with hourly replacement of intraoperative losses and maintenance fluids. The PPV-guided group received boluses to target PPV less than 13% in addition to maintenance fluids. Total intraoperative fluids administered and the incidence of hypotension was recorded along with the brain relaxation score. Postoperatively, serum lactate levels, periorbital and conjunctival edema, as well as postoperative nausea and vomiting were assessed. Statistical Analyses  All statistical analyses were performed with Statistical Package for Social Sciences, version-20 (SPSS-20, IBM, Chicago, Illinois, United States). To compare the means between the two groups (CVP vs. PPV), independent samples t -test was used for normal distribution data and Mann-Whitney U test for nonnormal distribution data. The chi-square test or Fischer's exact test was used for categorical variables. Results  The CVP group received significantly more intraoperative fluids than the PPV group (4,340 ± 1,010 vs. 3,540 ± 740 mL, p  < 0.01). Incidence of hypotension was lower in the PPV group (4 [11.1%] vs. 0 [0%], p  = 0.04). Brain relaxation scores, serum lactate levels, periorbital and conjunctival edema, and incidence of postoperative nausea and vomiting were comparable between the groups. Conclusion  The requirement for intraoperative fluids was less in PPV-guided fluid management with better hemodynamic stability, adequate brain conditions, and no compromise of perfusion.

Neurocognitive Sequelae and Rehabilitation after Subarachnoid Hemorrhage: Optimizing Outcomes

Subarachnoid hemorrhage (SAH) is a medical emergency that requires immediate intervention. The etiology varies between cases; however, rupture of an intracranial aneurysm accounts for 80% of medical emergencies. Early intervention and treatment are essential to prevent long-term complications. Over the years, treatment of SAH has drastically improved, which is responsible for the rapid rise in SAH survivors. Post-SAH, a significant number of patients exhibit impairments in memory and executive function and report high rates of depression and anxiety that ultimately affect daily living, return to work, and quality of life. Given the rise in SAH survivors, rehabilitation post-SAH to optimize patient outcomes becomes crucial. The review addresses the current rehabilitative strategies to combat the neurocognitive and behavioral issues that may arise following SAH.

A step-by-step guide for the diagnosis and management of hyponatraemia in patients with stroke

Hyponatraemia is common in patients with stroke and associated with adverse outcomes and increased mortality risk. The present review presents the underlying causes and provides a thorough algorithm for the diagnosis and management of hyponatraemia in stroke patients. Concomitant diseases and therapies, such as diabetes, chronic kidney disease and heart failure, along with diuretics, antidepressants and proton pump inhibitors are the most common causes of hyponatraemia in community. In the setting of acute stroke, the emergence of hyponatraemia might be attributed to the administration of hypotonic solutions and drugs (ie. mannitol and antiepileptics), poor solute intake, infections, as well as stroke-related conditions or complications, such as the syndrome of inappropriate secretion of antidiuretic hormone, cerebral salt wasting syndrome and secondary adrenal insufficiency. Diagnostically, the initial step is to differentiate hypotonic from non-hypotonic hyponatraemia, usually caused by hyperglycaemia or recent mannitol administration in patients with stroke. Determining urine osmolality, urine sodium level and volume status are the following steps in the differentiation of hypotonic hyponatraemia. Of note, specific parameters, such as fractional uric acid and urea excretion, along with plasma copeptin concentration, may further improve the diagnostic yield. Therapeutic options are based on the duration and symptoms of hyponatremia. In the case of acute or symptomatic hyponatraemia, hypertonic saline administration is recommended. Hypovolaemic chronic hyponatremia is treated with isotonic solution administration. Although fluid restriction remains the first-line treatment for the rest forms of chronic hyponatraemia, therapies increasing renal free water excretion may be necessary. Loop diuretics and urea serve this purpose in patients with stroke, whereas sodium-glucose transport protein-2 inhibitors appear to be a promising therapy. Nevertheless, it is yet unclear whether the appropriate restoration of sodium level improves outcomes in such patients. Randomized trials designed to compare therapeutic strategies in managing hyponatraemia in patients with stroke are required.

Fluid Stewardship of Maintenance Intravenous Fluids

Despite the frequent use of maintenance intravenous fluids (mIVF) in critically ill patients, limited guidance is available. Notably, fluid overload secondary to mIVF mismanagement is associated with significant adverse patient outcomes. The Four Rights (right drug, right dose, right duration, right patient) construct of fluid stewardship has been proposed for the safe evaluation and use of fluids. The purpose of this evidence-based review is to offer practical insights for the clinician regarding mIVF selection, dosing, and duration in line with the Four Rights of Fluid Stewardship.

The Brain–Gut Axis in Traumatic Brain Injury: Implications for Nutrition Support

Purpose of Review

Early enteral nutrition improves outcomes following traumatic brain injury (TBI). This can prove difficult due to TBI-induced feeding intolerance secondary to disruption of the brain-gut axis, a network composed of central nervous system (CNS) input, autonomic signaling, and immunologic regulation that controls gut and CNS homeostasis. Here, we discuss the pathophysiology of brain–gut axis dysregulation and outline nutrition strategies in patients with TBI.

Recent Findings

Feeding intolerance following TBI is multifactorial; complex signaling between the CNS, sympathetic nervous system, parasympathetic nervous system, and enteric nervous system that controls gut homeostasis is disrupted within hours post-injury. This has profound effects on the immune system and gut microbiome, further complicating post-TBI recovery. Despite this disruption, calorie and protein requirements increase considerably following TBI, and early nutritional supplementation improves survival following TBI. Enteral nutrition has proven more efficacious than parenteral nutrition in TBI patients and should be initiated within 48 hours following admission. Immune-fortified nutrition reduces CNS and gut inflammation and may improve outcomes in TBI patients.

Summary

Although autonomic dysregulation of the brain–gut axis results in feeding intolerance following TBI, early enteral nutrition is of paramount importance. Enteral nutrition reduces post-TBI inflammation and enhances immunologic and gut function. When feasible, enteral nutrition should be initiated within 48 hours following injury.

Hemodynamic management of acute brain injury caused by cerebrovascular diseases: a survey of the European Society of Intensive Care Medicine

BACKGROUND

The optimal hemodynamic targets and management of patients with acute brain injury are not completely elucidated, but recent evidence points to important impact on clinical outcomes. We performed an international survey with the aim to investigate the practice in the hemodynamic targets, monitoring, and management of patients with acute ischemic stroke (AIS), intracranial hemorrhage (ICH) and subarachnoid hemorrhage (SAH).

METHODS

This survey was endorsed by the European Society of Intensive Care (ESICM). An electronic questionnaire of 76 questions divided in 4 sections (general information, AIS, ICH, SAH specific questions) was available between January 2022 to March 2022 on the ESICM website.

RESULTS

One hundred fifty-four healthcare professionals from 36 different countries and at least 98 different institutions answered the survey. Routine echocardiography is routinely performed in 37% of responders in AIS, 34% in ICH and 38% in SAH. Cardiac output monitoring is used in less than 20% of cases by most of the responders. Cardiovascular complications are the main reason for using advanced hemodynamic monitoring, and norepinephrine is the most common drug used to increase arterial blood pressure. Most responders target fluid balance to neutral (62% in AIS, 59% in ICH,44% in SAH), and normal saline is the most common fluid used. Large variability was observed regarding the blood pressure targets.

CONCLUSIONS

Hemodynamic management and treatment in patients with acute brain injury from cerebrovascular diseases vary largely in clinical practice. Further research is required to provide clear guidelines to physicians for the hemodynamic optimization of this group of patients.

microRNAs in Subarachnoid Hemorrhage (Review of Literature)

Recently, many studies have shown that microRNAs (miRNAs) in extracellular bioliquids are strongly associated with subarachnoid hemorrhage (SAH) and its complications. The article presents issues related to the occurrence of subarachnoid hemorrhage (epidemiology, symptoms, differential diagnosis, examination, and treatment of the patient) and a review of current research on the correlation between miRNAs and the complications of SAH. The potential use of miRNAs as biomarkers in the treatment of SAH is presented.

Saline versus Balanced Crystalloids for Adults with Aneurysmal Subarachnoid Hemorrhage: A Subgroup Analysis of the SMART Trial

BACKGROUND

Whether the composition of intravenous crystalloid solutions affects outcomes in adults with aneurysmal subarachnoid hemorrhage (aSAH) remains unknown. Therefore, we determined whether the use of saline is associated with lower risk of disability and death in aSAH patients compared to balanced crystalloids.

METHODS

We conducted a post hoc subgroup analysis of the Isotonic Solutions and Major Adverse Renal Events Trial (SMART), a pragmatic, unblinded, cluster-randomized, multiple-crossover clinical trial that enrolled 15,802 adults between June 2015 and April 2017. We compared intravenous administration of saline to balanced crystalloids in consecutively enrolled aSAH patients aged 18 years or older whose ruptured aneurysm was procedurally secured at a single academic center in the United States. The primary outcome was the score on the modified Rankin scale (mRS, range, 0 [no symptoms] to 6 [death]) at 90 days obtained from a prospective institutional stroke registry. Secondary outcome included death by 90 days. Logistic or proportional odds regression models were used to test for between-group differences adjusted for age, hypertension, aSAH grade, and procedure type.

RESULTS

Of the 79 aSAH patients procedurally treated during the SMART study period, 78 were enrolled (median age, 58 years; IQR, 49 to 64.5; 64% female), with 41 (53%) assigned to saline and 37 (47%) to balanced crystalloids. Plasma-Lyte was the primary balanced crystalloid used. Among 72 patients with 90-day mRS assessment, the adjusted common odds ratio, aOR, for mRS was 0.68 (95% CI, 0.28-1.63; P=0.39), with values less than 1.0 favoring saline. By 90 days, 2/39 patients (5%) in the saline group and 9/35 (26%) in the balanced-crystalloids group had died (aOR, 0.06; 95% CI, 0.00-0.50; P=0.02).

CONCLUSIONS

Among procedurally treated aSAH patients, the risk of disability or death at 90 days did not significantly differ between saline and balanced crystalloids. Death occurred less frequently with saline than balanced crystalloids.

Rapid chest compression effects on intracranial pressure in patients with acute cerebral injury

BACKGROUND

Patients with acute brain injury often require invasive mechanical ventilation, increasing the risk of developing complications such as respiratory secretions retention. Rapid chest compression is a manual chest physiotherapy technique that aims to improve clearance of secretions in these patients. However, the rapid chest compression technique has been suggested to be associated with increased intracranial pressure in patients with acute brain injury. The aim of this work is to elucidate the effects of the technique on intracranial pressure in mechanically ventilated patients with acute brain injury. Furthermore, the effects of the technique in different volumes and flows recorded by the ventilator and the relationship between the pressure applied in the intervention group and the different variables will also be studied.

METHODS

Randomized clinical trial, double-blinded. Patients with acute brain injury on invasive mechanical ventilation > 48 h will be included and randomized in two groups. In the control group, a technique of passive hallux mobilization will be applied, and in the intervention group, it will be performed using the rapid chest compression technique. Intracranial pressure (main variable) will be collected with an intracranial pressure monitoring system placed at the lateral ventricles (Integra Camino).

DISCUSSION

The safety of chest physiotherapy techniques in patients at risk of intracranial hyperpressure is still uncertain. The aim of this study is to identify if the rapid manual chest compression technique is safe in ventilated patients with acute brain injury.

TRIAL REGISTRATION

NCT03609866 . Registered on 08/01/2018.

Challenges in the hemodynamic management of acute nontraumatic neurological injuries

PURPOSE OF REVIEW

To appraise the evidence from the literature and suggest an integrated hemodynamic approach of early and delayed phases of acute ischemic stroke (AIS), subarachnoid hemorrhage (SAH) and intracerebral hemorrhage (ICH).

RECENT FINDINGS

In AIS, the research aims to evaluate the optimal pressure control before, during and after the revascularization, to optimize the perfusion in the ischemic areas, minimizing the risk of hemorrhage or secondary damage to already infarcted areas. In the early phase of SAH, systemic pressure should be controlled to balance the risk of stroke, hypertension-related rebleeding, and maintenance of cerebral perfusion pressure. The late phase aims to minimize the risk of cerebral vasospasm by adapting systemic pressure and volemia to cerebral and systemic physiological hemodynamic targets. In the mild-to-moderate ICH, achieving SAP of less than 140 mmHg and greater than 110 mmHg may be considered as a beneficial target. Caution should be considered in lowering intensively SAP in severe ICH.

SUMMARY

In nontraumatic brain injuries, the hemodynamic management is strictly related to fluctuating physiology of these diseases, needing a strict control of pressure and flow variable to ensure both cerebral and systemic homeostasis.

Intracranial pressure management: moving beyond guidelines

PURPOSE OF REVIEW

The aim of this study was to provide an overview on advances in intracranial pressure (ICP) protocols for care, moving from traditional to more recent concepts.

RECENT FINDINGS

Deep understanding of mechanics and dynamics of fluids and solids have been introduced for intracranial physiology. The amplitude or the harmonics of the cerebral-spinal fluid and the cerebral blood waves shows more information about ICP than just a numeric threshold. When the ICP overcome the compensatory mechanisms that maintain the compliance within the skull, an intracranial compartment syndrome (ICCS) is defined. Autoregulation monitoring emerge as critical tool to recognize CPP management. Measurement of brain tissue oxygen will be a critical intervention for diagnosing an ICCS. Surgical procedures focused on increasing the physiological compliance and increasing the volume of the compartments of the skull.

SUMMARY

ICP management is a complex task, moving far than numeric thresholds for activation of interventions. The interactions of intracranial elements requires new interpretations moving beyond classical theories. Most of the traditional clinical studies supporting ICP management are not generating high class evidence. Recommendations for ICP management requires better designed clinical studies using new concepts to generate interventions according to the new era of personalized medicine.

Abstract No.: ABS0639: A comparison of the total intraoperative fluid administered by goal directed fluid therapy and conventional fluid therapy in isolated traumatic brain injury patients undergoing early decompressive craniectomy- a prospective randomised controlled trial

Background & Aims:

Traumatic brain injury patients are prone to osmotic and electrolyte disturbances, hence require a unique approach to fluid management. Primary aim of the study is to compare goal-directed therapy and conventional hemodynamic based therapy on total intra-operative fluid administered during decompressive craniectomy

Methods:

Prospective randomised controlled trial was conducted at PGIMER, accruing 64 adult patients with TBI undergoing decompressive craniectomy Goal directed fluid therapy (GDT) used Flo Trac, EV-1000 device (Edwards Lifesciences, Irvine, CA) to monitor Stroke volume variation, Cardiac index and mean arterial pressure Conventional fluid therapyutilisedcrystalloids infused at a rate of 2 ml/kg/hour with target MAP >70 mm of Hg. Quantitative variables were compared using unpaired t test if normally distributed, Mann Whitney U test was used for non-normally distributed quantitative and ordinal data. A P < 0.05 was considered statistically significant. The statistical analysis was done using IBM SPSS version 25.

Results:

There was a numerical difference in total fluid administered between both the groups but did not prove to be statistically significant (p=0.511). No significant difference in intraoperative blood loss (p=0.776), urine output (p=0.230), total ventilator days (p=0.30), total ICU days (p=0.34), total hospital days (p=0.57) and GCS at discharge (0.53). There was significant difference in levels of hematocrit (p=0.00) and levels of lactate (p=0.00) within both the groups and GCS pre- and post-surgery (p=0.04)

Conclusion:

No statistically significant difference between the total intraoperative fluid administered between both the groups was observed. Quest for methods to improve outcome in traumatic brain injury patients it still ongoing.

Focused Management of Patients With Severe Acute Brain Injury and ARDS

Considering the COVID-19 pandemic where concomitant occurrence of ARDS and severe acute brain injury (sABI) has increasingly coemerged, we synthesize existing data regarding the simultaneous management of both conditions. Our aim is to provide readers with fundamental principles and concepts for the management of sABI and ARDS, and highlight challenges and conflicts encountered while managing concurrent disease. Up to 40% of patients with sABI can develop ARDS. Although there are trials and guidelines to support the mainstays of treatment for ARDS and sABI independently, guidance on concomitant management is limited. Treatment strategies aimed at managing severe ARDS may at times conflict with the management of sABI. In this narrative review, we discuss the physiological basis and risks involved during simultaneous management of ARDS and sABI, summarize evidence for treatment decisions, and demonstrate these principles using hypothetical case scenarios. Use of invasive or noninvasive monitoring to assess brain and lung physiology may facilitate goal-directed treatment strategies with the potential to improve outcome. Understanding the pathophysiology and key treatment concepts for comanagement of these conditions is critical to optimizing care in this high-acuity patient population.

The effect of the volemic and cardiac status on brain oxygenation in patients with subarachnoid hemorrhage: a bi-center cohort study

Background

Fluid management in patients after subarachnoid hemorrhage (SAH) aims at the optimization of cerebral blood flow and brain oxygenation. In this study, we investigated the effects of hemodynamic management on brain oxygenation by integrating advanced hemodynamic and invasive neuromonitoring.

Methods

This observational cohort bi-center study included data of consecutive poor-grade SAH patients who underwent pulse contour cardiac output (PiCCO) monitoring and invasive neuromonitoring. Fluid management was guided by the transpulmonary thermodilution system and aimed at euvolemia (cardiac index, CI ≥ 3.0 L/min/m²; global end-diastolic index, GEDI 680–800 mL/m²; stroke volume variation, SVV < 10%). Patients were managed using a brain tissue oxygenation (P_btO₂) targeted protocol to prevent brain tissue hypoxia (BTH, P_btO₂ < 20 mmHg). To assess the association between CI and P_btO₂ and the effect of fluid challenges on CI and P_btO₂, we used generalized estimating equations to account for repeated measurements.

Results

Among a total of 60 included patients (median age 56 [IQRs 47–65] years), BTH occurred in 23% of  the monitoring time during the first 10 days since admission. Overall, mean CI was within normal ranges (ranging from 3.1 ± 1.3 on day 0 to 4.1 ± 1.1 L/min/m² on day 4). Higher CI levels were associated with higher P_btO₂ levels (Wald = 14.2; p < 0.001). Neither daily fluid input nor fluid balance was associated with absolute P_btO₂ levels (p = 0.94 and p = 0.85, respectively) or the occurrence of BTH (p = 0.68 and p = 0.71, respectively). P_btO₂ levels were not significantly different in preload dependent patients compared to episodes of euvolemia. P_btO₂ increased as a response to fluid boluses only if BTH was present at baseline (from 13 ± 6 to 16 ± 11 mmHg, OR = 13.3 [95% CI 2.6–67.4], p = 0.002), but not when all boluses were considered (p = 0.154).

Conclusions

In this study a moderate association between increased cardiac output and brain oxygenation was observed. Fluid challenges may improve P_btO₂ only in the presence of baseline BTH. Individualized hemodynamic management requires advanced cardiac and brain monitoring in critically ill SAH patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-021-00960-z.

Albumin Use in Brain-injured and Neurosurgical Patients: Concepts, Indications, and Controversies

Human albumin has been used extensively for decades as a nonwhole blood plasma replacement fluid in the perioperative and critical care setting. Its potential advantages as a highly effective volume expander must be weighed, however, against its potential harm for patients in the context of various neurological states and for various neurosurgical interventions. This narrative review explores the physiological considerations of intravenous human albumin as a replacement fluid and examines the extant clinical evidence for and against its use within the various facets of modern neuroanesthesia and neurocritical care practice.

Dehydration and Headache

PURPOSE OF REVIEW

We define dehydration and its relationship to pain physiology including both primary and secondary headache disorders.

RECENT FINDINGS

Intravenous fluids administered for acute migraine attacks in an emergency department setting have not been shown to improve pain outcomes. However, increased intravascular volume before diagnostic lumbar puncture may reduce the frequency of post-lumbar puncture headache from iatrogenic spinal fluid leak. Maintenance of euhydration can help treat orthostatic and "coat-hanger" headache due to autonomic disorders. Similarly, prevention of fluid losses can mitigate secondary headaches provoked by dehydration such as cerebral venous thrombosis or pituitary apoplexy. Dehydration alone may cause headache, but oftentimes exacerbates underlying medical conditions such as primary headache disorders or other conditions dependent on fluid balance.

Positive fluid balance is associated with death and severity of brain injury in neonates with hypoxic-ischemic encephalopathy

OBJECTIVE

To investigate the association between fluid balance during therapeutic hypothermia (TH) and severity of brain injury on magnetic resonance imaging (MRI) in neonates with hypoxic-ischemic encephalopathy (HIE).

STUDY DESIGN

This is a secondary analysis of data from a prospective observational study in neonates with HIE. Daily net positive fluid balance during TH was investigated for association with the adverse primary outcome of death or moderate-to-severe brain injury on MRI using multivariable logistic regression.

RESULTS

Of the 150 neonates included, 50 suffered adverse outcome and had significantly higher net positive fluid balance (53 vs. 19 ml/kg/day, p < 0.01) during first 24 hours of TH. Neonates with a net positive fluid balance (>25 ml/kg/day) at 24 hours of TH had 3.4 (95% CI 1.3-9) times higher odds of adverse outcome.

CONCLUSIONS

Positive fluid balance during TH in neonates with HIE is independently associated with death or moderate-to-severe brain injury on MRI.

High Chloride Burden and Clinical Outcomes in Critically Ill Patients With Large Hemispheric Infarction

Background: In general, disease severity has been found to be associated with abnormal chloride levels in critically ill patients, but hyperchloremia is associated with mixed results regarding patient-centered clinical outcomes. We aimed to investigate the impact of maximum serum chloride concentration on the clinical outcomes of critically ill patients with large hemispheric infarction (LHI).

Methods: We conducted a retrospective observational cohort study using prospective institutional neurocritical care registry data from 2013 to 2018. Patients with LHIs involving over two-thirds of middle cerebral artery territory, with or without infarction of other vascular territories, and a baseline National Institutes of Health Stroke Scale score of ≥13 were assessed. Those with a baseline creatinine clearance of <15 mL/min and required neurocritical care for <72 h were excluded. Primary outcome was in-hospital mortality. Secondary outcomes included 3-month mortality and acute kidney injury (AKI) occurrence. Outcomes were compared to different maximum serum chloride levels (5 mmol/L increases) during the entire hospitalization period using multivariable logistic regression analyses.

Results: Of 90 patients, 20 (22.2%) died in-hospital. Patients who died in-hospital had significantly higher maximum serum chloride levels than did those who survived up to hospital discharge (139.7 ± 8.1 vs. 119.1 ± 10.4 mmol/L; p < 0.001). After adjusting for age, sex, and Glasgow coma scale score, each 5-mmol/L increase in maximum serum chloride concentration was independently associated with an increased risk of in-hospital mortality (adjusted odds ratio (aOR), 4.34; 95% confidence interval [CI], 1.98–9.50; p < 0.001). Maximum serum chloride level was also an independent risk factor for 3-month mortality (aOR, 1.99 [per 5 mmol/L increase]; 95% CI, 1.42–2.79; p < 0.001) and AKI occurrence (aOR, 1.57 [per 5 mmol/L increase]; 95% CI, 1.18–2.08; p = 0.002).

Conclusions: High maximum serum chloride concentrations were associated with poor clinical outcomes in critically ill patients with LHI. This study highlights the importance of monitoring serum chloride levels and avoiding hyperchloremia in this patient population.

Post-operative fluid overload as a predictor of hospital and long-term outcomes in a pediatric heart transplant population

BACKGROUND

Pediatric patients undergoing heart transplant have a number of factors predisposing them to become fluid-overloaded, including capillary leak syndrome. Capillary leak and FO are associated with organ injury and may influence both short- and long-term outcomes. This study aimed to 1) determine the extent, timing, and predictors of post-operative FO and 2) investigate the association of FO with clinically important outcomes.

METHODS

Between 2000 and 2012, 70 children less than 6 years old had a heart transplant at our institution. This was a secondary analysis of data from an ongoing prospective cohort study.

RESULTS

FO, defined as cumulative fluid balance greater than 10% of body weight in the first 5 post-operative days, occurred in 16/70 patients (23%); 7 of these had more than 20% FO. Shorter donor ischemic time and longer cardiopulmonary bypass time were independently associated with increased risk of FO. FO >20% was a statistically significant independent predictor of mortality (P = .005), ventilation time, and PICU length of stay. There was no statistically significant association between identified neurodevelopment domains and FO.

CONCLUSIONS

Our single-center experience demonstrates that FO was common after pediatric heart transplant and was associated with worse clinical outcomes. FO is a potentially modifiable factor, and research is needed to better determine risk factors and whether intervention to reduce FO can improve outcomes in pediatric heart transplant patients.

International Practice Variability in Treatment of Aneurysmal Subarachnoid Hemorrhage

Prior research suggests substantial between-center differences in functional outcome following aneurysmal subarachnoid hemorrhage (aSAH). One hypothesis is that these differences are due to practice variability. To characterize practice variability, we sent a survey to 230 centers, of which 145 (63%) responded. Survey respondents indicated that an estimated 65% of ruptured aneurysms were treated endovascularly. Sixty-five percent of aneurysms were treated within 24 h of symptom onset, 18% within 24–48 h, and eight percent within 48–72 h. Centers in the United States (US) and Europe (EU) treat aneurysms more often endovascularly (72% and 70% vs. 51%, respectively, US vs. other p < 0.001, and EU vs. other p < 0.01) and more often within 24 h (77% and 64% vs. 46%, respectively, US vs. other p < 0.001, EU vs. other p < 0.01) compared to other centers. Most centers aim for euvolemia (96%) by administrating intravenous fluids to 0 (53%) or +500 mL/day (41%) net fluid balance. Induced hypertension is more often used in US centers (100%) than in EU (87%, p < 0.05) and other centers (81%, p < 0.05), and endovascular therapies for cerebral vasospasm are used more often in US centers than in other centers (91% and 60%, respectively, p < 0.05). We observed significant practice variability in aSAH treatment worldwide. Future comparative effectiveness research studies are needed to investigate how practice variation leads to differences in functional outcome.

[Clinical efficacy of restrictive fluid management in patients with severe traumatic brain injury]

OBJECTIVE

To investigate the effects of restrictive fluid management in patients with severe traumatic brain injury (sTBI).

METHODS

Between January, 2019 and June, 2020, we randomly assigned 51 postoperative patients (stay in the ICU of no less than 7 days) with sTBI into treatment group (n=25) with restrictive fluid management and the control group (n=26) with conventional fluid management. The data of optic nerve sheath diameter (ONSD), middle cerebral artery pulsatility index (MAC- PI), neuron-specific enolase (NSE) level, inferior vena cava (IVC) diameter, Glascow Coma Scale (GCS) score, mean arterial blood pressure, heart rate, and fluid balance of the patients were collected at ICU admission and at 1, 3 and 7 days after ICU admission, and the duration of mechanical ventilation, ICU stay, and 28-day mortality were recorded.

RESULTS

The cumulative fluid balance of the two groups were positive on day 1 and negative on days 3 and 7 after ICU admission; at the same time points, the patients in the treatment group had significantly greater negative fluid balance than those in the control group (P < 0.05). In both of the groups, the ONSD and MCA-PI values were significantly higher on day 1 than the baseline (P < 0.05), reached the peak levels on day 3, and decreased on day 7; at the same time point, these values were significantly lower in the treatment group than in the control group (P < 0.05). No significant difference was found in NSE level on day 1 between the two groups (P>0.05); on day 3, NSE level reached the peak level and was significantly higher in the control group (P < 0.05); on day 7, NSE level was lowered the level of day 1 in the treatment group but remained higher than day 1 level in the control group. The 28-day mortality rate did not differ significantly between the two groups (16.00% vs 23.08%, P>0.05); the duration of mechanical ventilation, length of ICU stay, and the number of tracheotomy were all significantly shorter or lower in the treatment group than in the control group (P < 0.05).

CONCLUSIONS

Restrictive fluid management can reduce cerebral edema and improve the prognosis but does not affect the 28-day mortality of patients with sTBI.

Terms, Definitions, Nomenclature, and Routes of Fluid Administration

Fluid therapy is administered to veterinary patients in order to improve hemodynamics, replace deficits, and maintain hydration. The gradual expansion of medical knowledge and research in this field has led to a proliferation of terms related to fluid products, fluid delivery and body fluid distribution. Consistency in the use of terminology enables precise and effective communication in clinical and research settings. This article provides an alphabetical glossary of important terms and common definitions in the human and veterinary literature. It also summarizes the common routes of fluid administration in small and large animal species.

The Prognostic Role of Lactate Concentrations after Aneurysmal Subarachnoid Hemorrhage

Blood lactate concentrations are often used to assess global tissue perfusion in critically ill patients; however, there are scarce data on lactate concentrations after subarachnoid hemorrhage (SAH). We aimed to assess the prognostic role of serial blood lactate measurements on hospital mortality and neurological outcomes at 3 months after SAH. We reviewed all SAH patients admitted to the intensive care unit from 2007 to 2019 and recorded the highest daily arterial lactate concentration for the first 6 days. Patients with no lactate concentration were excluded. Hyperlactatemia was defined as a blood lactate concentration >2.0 mmol/L. A total of 456 patients were included: 158 (35%) patients died in hospital and 209 (46%) had an unfavorable outcome (UO) at 3 months. The median highest lactate concentration was 2.7 (1.8–3.9) mmol/L. Non-survivors and patients with UO had significantly higher lactate concentrations compared to other patients. Hyperlactatemia increased the chance of dying (OR 4.19 (95% CI 2.38–7.39)) and of having UO in 3 months (OR 4.16 (95% CI 2.52–6.88)) after adjusting for confounding factors. Therefore, initial blood lactate concentrations have prognostic implications in patients with SAH; their role in conjunction with other prognostic indicators should be evaluated in prospective studies.

Immunomodulatory Effect of Hypertonic Saline Solution in Traumatic Brain-Injured Patients and Intracranial Hypertension

Traumatic brain injury (TBI) is often associated with an increase in the intracranial pressure (ICP). This increase in ICP can cross the physiological range and lead to a reduction in cerebral perfusion pressure (CPP) and the resultant cerebral blood flow (CBF). It is this reduction in the CBF that leads to the secondary damage to the neural parenchyma along with the physical axonal and neuronal damage caused by the mass effect. In certain cases, a surgical intervention may be required to either remove the mass lesion (hematoma of contusion evacuation) or provide more space to the insulted brain to expand (decompressive craniectomy). Whether or not a surgical intervention is performed, all these patients require some form of pharmaceutical antiedema agents to bring down the raised ICP. These agents have been broadly classified as colloids (e.g., mannitol, glycerol, urea) and crystalloids (e.g., hypertonic saline), and have been used since decades. Even though mannitol has been the workhorse for ICP reduction owing to its unique properties, crystalloids have been found to be the preferred agents, especially when long-term use is warranted. The safest and most widely used agent is hypertonic saline in various concentrations. Whatever be the concentration, hypertonic saline has created special interest among physicians owing to its additional property of immunomodulation and neuroprotection. In this review, we summarize and understand the various mechanism by which hypertonic saline exerts its immunomodulatory effects that helps in neuroprotection after TBI.

Lack of Association between Low Cumulative Dose of Hydroxyethyl Starch and Acute Kidney Injury in Patients with Acute Ischemic Stroke

BACKGROUND

Hydroxyethyl starch (HES, 6% 130/0.4) has been used as a volume expander for the treatment of cerebral hypoperfusion in acute ischemic stroke. Although HES use was associated with renal failure in sepsis or critical illness, it still remains to be elucidated whether HES is linked to renal adverse events in patients with acute ischemic stroke.

METHODS

A total of 524 patients with acute ischemic stroke within 7 days of onset were included between January 2012 and May 2016. Renal function on admission and follow-up on day 7 ± 2 was assessed using serum creatinine (SCr) and estimated glomerular filtration rate (eGFR). Propensity score matching (PSM) was used to perform a 1:1 matched-pair analysis to minimize the group differences caused by covariates. The percentage of patients with new-onset acute renal injury (AKI) using the Kidney Disease: Improving Global Outcomes or good functional outcome (modified Rankin Scale 0-2) at 90 days were compared between HES cohort and controls.

RESULTS

Among the included patients (mean age, 68.6 years; male, 56.5%), 81 patients (15.5%) were HES cohort (median cumulative dose, 1,450 mL). Baseline renal function was better in HES cohort compared to that in the controls (SCr, 0.87 ± 0.43 mg/dL vs. 1.15 ± 1.15 mg/dL, P < 0.001; eGFR, 86.91 ± 24.27 mL/min vs. 74.55 ± 29.58 mL/min, P < 0.001), which became not significant in PSM cohort (72 pairs). The percentage of new-onset AKI did not differ between the HES cohort and controls (1.4% vs. 1.4%, P = 1.000). In addition, new-onset AKI was not related to HES (odds ratio, 1.422; 95% confidence interval, 0.072-28.068; P = 0.817) after adjusting for confounders. HES cohort tended to have higher percentage of good functional outcome at 90 days compared to controls, which failed to reach statistical significance (68.1% vs. 54.2%, P = 0.087).

CONCLUSION

A low cumulative dose of HES was not associated with renal adverse events in patients with acute ischemic stroke.

Lessons from the CONSCIOUS-1 Study

After years of research on treatment of aneurysmal subarachnoid hemorrhage (aSAH), including randomized clinical trials, few treatments have been shown to be efficacious. Nevertheless, reductions in morbidity and mortality have occurred over the last decades. Reasons for the improved outcomes remain unclear. One randomized clinical trial that has been examined in detail with these questions in mind is Clazosentan to Overcome Neurological Ischemia and Infarction Occurring After Subarachnoid Hemorrhage (CONSCIOUS-1). This was a phase-2 trial testing the effect of clazosentan on angiographic vasospasm (aVSP) in patients with aSAH. Clazosentan decreased moderate to severe aVSP. There was no statistically significant effect on the extended Glasgow outcome score (GOS), although the study was not powered for this endpoint. Data from the approximately 400 patients in the study were detailed, rigorously collected and documented and were generously made available to one investigator. Post-hoc analyses were conducted which have expanded our knowledge of the management of aSAH. We review those analyses here.

Nutrition Therapy, Glucose Control, and Brain Metabolism in Traumatic Brain Injury: A Multimodal Monitoring Approach

The goal of neurocritical care in patients with traumatic brain injury (TBI) is to prevent secondary brain damage. Pathophysiological mechanisms lead to loss of body mass, negative nitrogen balance, dysglycemia, and cerebral metabolic dysfunction. All of these complications have been shown to impact outcomes. Therapeutic options are available that prevent or mitigate their negative impact. Nutrition therapy, glucose control, and multimodality monitoring with cerebral microdialysis (CMD) can be applied as an integrated approach to optimize systemic immune and organ function as well as adequate substrate delivery to the brain. CMD allows real-time bedside monitoring of aspects of brain energy metabolism, by measuring specific metabolites in the extracellular fluid of brain tissue. Sequential monitoring of brain glucose and lactate/pyruvate ratio may reveal pathologic processes that lead to imbalances in supply and demand. Early recognition of these patterns may help individualize cerebral perfusion targets and systemic glucose control following TBI. In this direction, recent consensus statements have provided guidelines and recommendations for CMD applications in neurocritical care. In this review, we summarize data from clinical research on patients with severe TBI focused on a multimodal approach to evaluate aspects of nutrition therapy, such as timing and route; aspects of systemic glucose management, such as intensive vs. moderate control; and finally, aspects of cerebral metabolism. Research and clinical applications of CMD to better understand the interplay between substrate supply, glycemic variations, insulin therapy, and their effects on the brain metabolic profile were also reviewed. Novel mechanistic hypotheses in the interpretation of brain biomarkers were also discussed. Finally, we offer an integrated approach that includes nutritional and brain metabolic monitoring to manage severe TBI patients.

The Effect of Fluid Loading and Hypertonic Saline Solution on Cortical Cerebral Microcirculation and Glycocalyx Integrity

BACKGROUND

Fluid loading and hyperosmolar solutions can modify the cortical brain microcirculation and the endothelial glycocalyx (EG). This study compared the short-term effects of liberal fluid loading with a restrictive fluid intake followed by osmotherapy with hypertonic saline (HTS) on cerebral cortical microcirculation and EG integrity in a rabbit craniotomy model.

METHODS

The experimental rabbits were allocated randomly to receive either <2 mL/kg/h (group R, n=14) or 30 mL/kg/h (group L, n=14) of balanced isotonic fluids for 1 hour. Then, the animals were randomized to receive 5 mL/kg intravenous infusion of either 3.2% saline (group HTS, n=14) or 0.9% saline (group normal saline, n=13) in a 20-minute infusion. Microcirculation in the cerebral cortex based on sidestream dark-field imaging, a morphologic index of glycocalyx damage to sublingual and cortical brain microcirculation (the perfused boundary region), and serum syndecan-1 levels were evaluated.

RESULTS

Lower cortical brain perfused small vessel density (P=0.0178), perfused vessel density (P=0.0286), and total vessel density (P=0.0447) were observed in group L, compared with group R. No differences were observed between the HTS and normal saline groups after osmotherapy. Cerebral perfused boundary region values (P=0.0692) and hematocrit-corrected serum syndecan-1 levels (P=0.0324) tended to be higher in group L than in group R animals.

CONCLUSIONS

Liberal fluid loading was associated with altered cortical cerebral microcirculation and EG integrity parameters. The 3.2% saline treatment did not affect cortical cerebral microcirculation or EG integrity markers.

Performance of Electrical Velocimetry for Noninvasive Cardiac Output Measurements in Perioperative Patients After Subarachnoid Hemorrhage

BACKGROUND

Fluid therapy guided by cardiac output measurements is of particular importance for adequate cerebral perfusion and oxygenation in neurosurgical patients. We examined the usefulness of a noninvasive electrical velocimetry (EV) device based on the thoracic bioimpedance method for perioperative hemodynamic monitoring in patients after aneurysmal subarachnoid hemorrhage.

PATIENTS AND METHODS

In total, 18 patients who underwent surgical clipping or endovascular coiling for ruptured aneurysms were examined prospectively. Simultaneous cardiac index (CI) measurements obtained with EV (CIEV) and reference transpulmonary thermodilution (CITPTD) were compared. A total of 223 pairs of data were collected.

RESULTS

A significant correlation was found between CIEV and CITPTD (r=0.86; P<0.001). Bland and Altman analysis revealed a bias between CIEV and CITPTD of -0.06 L/min/m, with limits of agreement of ±1.14 L/min/m and a percentage error of 33%. Although the percentage error for overall data was higher than the acceptable limit of 30%, subgroup analysis during the postoperative phase showed better agreement (23% vs. 42% during the intraprocedure phase). Four-quadrant plot and polar plot analyses showed fair-to-poor trending abilities (concordance rate of 90% to 91%, angular bias of +17 degrees, radial limits of agreement between ±37 and ±40 degrees, and polar concordance rate of 72% to 75%), including the subgroup analysis.

CONCLUSIONS

Absolute CI values obtained from EV and TPTD are not interchangeable with TPTD for perioperative use in subarachnoid hemorrhage patients. However, considering the moderate levels of agreement with marginal trending ability during the early postoperative phase, this user-friendly device can provide an attractive monitoring option during neurocritical care.

High Early Fluid Input After Aneurysmal Subarachnoid Hemorrhage: Combined Report of Association With Delayed Cerebral Ischemia and Feasibility of Cardiac Output-Guided Fluid Restriction

BACKGROUND

Guidelines on the management of aneurysmal subarachnoid hemorrhage (aSAH) recommend euvolemia, whereas hypervolemia may cause harm. We investigated whether high early fluid input is associated with delayed cerebral ischemia (DCI), and if fluid input can be safely decreased using transpulmonary thermodilution (TPT).

METHODS

We retrospectively included aSAH patients treated at an academic intensive care unit (2007-2011; cohort 1) or managed with TPT (2011-2013; cohort 2). Local guidelines recommended fluid input of 3 L daily. More fluids were administered when daily fluid balance fell below +500 mL. In cohort 2, fluid input in high-risk patients was guided by cardiac output measured by TPT per a strict protocol. Associations of fluid input and balance with DCI were analyzed with multivariable logistic regression (cohort 1), and changes in hemodynamic indices after institution of TPT assessed with linear mixed models (cohort 2).

RESULTS

Cumulative fluid input 0 to 72 hours after admission was associated with DCI in cohort 1 (n=223; odds ratio [OR] 1.19/L; 95% confidence interval 1.07-1.32), whereas cumulative fluid balance was not. In cohort 2 (23 patients), using TPT fluid input could be decreased from 6.0 ± 1.0 L before to 3.4 ± 0.3 L; P = .012), while preload parameters and consciousness remained stable.

CONCLUSION

High early fluid input was associated with DCI. Invasive hemodynamic monitoring was feasible to reduce fluid input while maintaining preload. These results indicate that fluid loading beyond a normal preload occurs, may increase DCI risk, and can be minimized with TPT.

Modern Management of Bleeding, Clotting, and Coagulopathy in Trauma Patients: What Is the Role of Viscoelastic Assays?

Purpose of Review

The purpose of this review is to briefly outline the current state of hemorrhage control and resuscitation in trauma patients with a specific focus on the role viscoelastic assays have in this complex management, to include indications for use across all phases of care in the injured patient.

Recent Findings

Viscoelastic assay use to guide blood-product resuscitation in bleeding trauma patients can reduce mortality by up to 50%. Viscoelastic assays also reduce total blood products transfused, reduce ICU length of stay, and reduce costs. There are a large number of observational and retrospective studies evaluating viscoelastic assay use in the initial trauma resuscitation, but only one randomized control trial. There is a paucity of data evaluating use of viscoelastic assays in the operating room, post-operatively, and during ICU management in trauma patients, rendering their use in these settings extrapolative/speculative based on theory and data from other surgical disciplines and settings.

Summary

Both hypocoagulable and hypercoagulable states exist in trauma patients, and better indicate what therapy may be most appropriate. Further study is needed, particularly in the operating room and post-operative/ICU settings in trauma patients.

Common Data Elements for Unruptured Intracranial Aneurysms and Aneurysmal Subarachnoid Hemorrhage: Recommendations from the Working Group on Hospital Course and Acute Therapies-Proposal of a Multidisciplinary Research Group

INTRODUCTION

The Common Data Elements (CDEs) initiative is a National Institute of Health/National Institute of Neurological Disorders and Stroke (NINDS) effort to standardize naming, definitions, data coding, and data collection for observational studies and clinical trials in major neurological disorders. A working group of experts was established to provide recommendations for Unruptured Aneurysms and Aneurysmal Subarachnoid Hemorrhage (SAH) CDEs.

METHODS

This paper summarizes the recommendations of the Hospital Course and Acute Therapies after SAH working group. Consensus recommendations were developed by assessment of previously published CDEs for traumatic brain injury, stroke, and epilepsy. Unruptured aneurysm- and SAH-specific CDEs were also developed. CDEs were categorized into "core", "supplemental-highly recommended", "supplemental" and "exploratory".

RESULTS

We identified and developed CDEs for Hospital Course and Acute Therapies after SAH, which included: surgical and procedure interventions; rescue therapy for delayed cerebral ischemia (DCI); neurological complications (i.e. DCI; hydrocephalus; rebleeding; seizures); intensive care unit therapies; prior and concomitant medications; electroencephalography; invasive brain monitoring; medical complications (cardiac dysfunction; pulmonary edema); palliative comfort care and end of life issues; discharge status. The CDEs can be found at the NINDS Web site that provides standardized naming, and definitions for each element, and also case report form templates, based on the CDEs.

CONCLUSION

Most of the recommended Hospital Course and Acute Therapies CDEs have been newly developed. Adherence to these recommendations should facilitate data collection and data sharing in SAH research, which could improve the comparison of results across observational studies, clinical trials, and meta-analyses of individual patient data.

Fluid Balance Variations During the Early Phase of Large Hemispheric Stroke Are Associated With Patients' Functional Outcome

Background: From the variety of factors underlying the ischemia-associated edema formation in large hemispheric stroke (LHS), an increased brain water content during the early phase seems to have a pivotal role for long-lasting tissue damage. However, the importance of the fluid management during the acute phase of LHS has so far not been adequately studied. Therefore, this study explored the association between the fluid balance and functional outcome in patients suffering from LHS. Methods: We analyzed hospital-based medical records of 39 consecutive patients with LHS and decompressive hemicraniectomy. Over the first 10 days after admission, the volumes of all administered fluids were assessed daily and corrected for daily urinary output and insensible loss. Functional outcome at 3 months was assessed with the modified Rankin Scale (mRS) and dichotomized into an acceptable (mRS ≤ 4) vs. a poor outcome (mRS ≥ 5). Results: Compared to patients with a poor functional outcome (n = 19), those with an acceptable outcome (n = 20) were characterized by a significantly lower cumulative net fluid balance at day 5 (1.6 ± 2.5 vs. 3.4 ± 4.4 l), day 7 (2.0 ± 2.9 vs. 4.6 ± 5.2 l), and day 10 (0 ± 2.5 vs. 5.6 ± 6.2 l). In addition to age, only the cumulative net fluid balance at day 10 served as an independent factor for poor functional outcome in multiple regression analyses. Conclusion: These data provide evidence for a critical role of the early phase net fluid balance with respect to the functional outcome after LHS. This observation leads to the hypothesis that patients with LHS might benefit from a more restrictive volume therapy. However, prospective studies are warranted to establish a causal relationship and recommendations for treatment strategies.

Balanced Crystalloids Versus Saline for Perioperative Intravenous Fluid Administration in Children Undergoing Neurosurgery: A Randomized Clinical Trial

BACKGROUND

Balanced crystalloid solutions induce less hyperchloremia than normal saline, but their role as primary fluid replacement for children undergoing surgery is unestablished. We hypothesized that balanced crystalloids induce less chloride and metabolic derangements than 0.9% saline solutions in children undergoing brain tumor resection.

METHODS

In total, 53 patients (age range, 6 mo to 12 y) were randomized to receive balanced crystalloid (balanced group) or 0.9% saline solution (saline group) during and after (for 24 h) brain tumor resection. Serum electrolyte and arterial blood gas analyses were performed at the beginning of surgery (baseline), after surgery, and at postoperative day 1. The primary trial outcome was the absolute difference in serum chloride concentrations (post-preopΔCl) measured after surgery and at baseline. Secondary outcomes included the post-preopΔ of other electrolytes and base excess (BE); hyperchloremic acidosis incidence; and the brain relaxation score, a 4-point scale evaluated by the surgeon for assessing brain edema.

RESULTS

Saline infusion increased post-preopΔCl (6 [3.5; 8.5] mmol/L) compared with balanced crystalloid (0 [-1.0; 3.0] mmol/L; P<0.001). Saline use also resulted in increased post-preopΔBE (-4.4 [-5.0; -2.3] vs. -0.4 [-2.7; 1.3] mmol/L; P<0.001) and hyperchloremic acidosis incidence (6/25 [24%] vs. 0; P=0.022) compared with balanced crystalloid. Brain relaxation score was comparable between groups.

CONCLUSIONS

In children undergoing brain tumor resection, saline infusion increased variation in serum chloride compared with balanced crystalloid. These findings support the use of balanced crystalloid solutions in children undergoing brain tumor resection.

Fluid Management in Acute Brain Injury

PURPOSE OF THE REVIEW

The aims of fluid management in acute brain injury are to preserve or restore physiology and guarantee appropriate tissue perfusion, avoiding potential iatrogenic effects. We reviewed the literature, focusing on the clinical implications of the selected papers. Our purposes were to summarize the principles regulating the distribution of water between the intracellular, interstitial, and plasma compartments in the normal and the injured brain, and to clarify how these principles could guide fluid administration, with special reference to intracranial pressure control.

RECENT FINDINGS

Although a considerable amount of research has been published on this topic and in general on fluid management in acute illness, the quality of the evidence tends to vary. Intravascular volume management should aim for euvolemia. There is evidence of harm with aggressive administration of fluid aimed at achieving hypervolemia in cases of subarachnoid hemorrhage. Isotonic crystalloids should be the preferred agents for volume replacement, while colloids, glucose-containing hypotonic solutions, and other hypotonic solutions or albumin should be avoided. Osmotherapy seems to be effective in intracranial hypertension management; however, there is no clear evidence regarding the superiority of hypertonic saline over mannitol. Fluid therapy plays an important role in the management of acute brain injury patients. However, fluids are a double-edged weapon because of the potential risk of hyper-hydration, hypo- or hyper-osmolar conditions, which may unfavorably affect the clinical course and the outcome.

Comparison of crystalloid resuscitation fluids for treatment of acute brain injury: a clinical and pre-clinical systematic review and network meta-analysis protocol

BACKGROUND

Current guidelines identify the choice of fluid resuscitation as important in minimizing the incidence of secondary brain injury from cerebral edema. It is widely accepted that isotonic crystalloid resuscitation fluids, specifically normal saline (NS), are optimal for resuscitation and that other relatively hypotonic fluids, such as Ringer's lactate (RL), should be avoided in this patient population. The aim of this review is to systematically compare the use of relatively hypotonic versus isotonic crystalloid resuscitation fluids in clinical and pre-clinical models of acute brain injury and their effect on outcomes. In recognition of the potential need for a network meta-analysis (NMA), we have also included all other relevant crystalloid resuscitation fluids as interventions of relevance to potentially inform indirect comparisons.

METHODS

Systematic searches of MEDLINE, Embase, and Web of Science BIOSIS Previews® will be used to identify eligible clinical and pre-clinical studies, which included studies examining acute brain injury (human and in vivo animal brain injury models) within the first 7 days of therapy. The intervention of interest is the intravenous use of relatively hypotonic crystalloid resuscitation fluids (e.g., Ringer's lactate, Hartmann's or Plasma Lyte® fluids). The main comparator of interest is an isotonic crystalloid resuscitation fluid, specifically normal saline (0.9%). Other crystalloid resuscitation fluids (e.g., hypertonic saline (3-23.4%)) will also be included as an additional intervention of interest. The primary outcome measures of interest are intracranial pressure (ICP) and cerebral perfusion pressure (CPP). Secondary outcomes include the effect of resuscitation on cerebral edema, brain and serum osmolarity, and electrolyte concentrations and clinical outcomes including modified Rankin Scale (mRS), (extended) Glasgow Outcome Scale (GOS/eGOS), and mortality. Separate meta-analyses will be conducted to quantify the effects of the different fluid resuscitation on acute brain injury outcomes in clinical and pre-clinical populations. Network meta-analyses to compare interventions will also be performed to compare the effects of different interventions.

DISCUSSION

This systematic review will comprehensively summarize the difference in treatment efficacy of various crystalloid resuscitation fluids in acute brain injury. This review is essential to underscore the evidence, or lack thereof, present in the literature to date to support current preference-driven practice and to direct future study.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO #CRD42016042960.

Hyperchloremia Is Associated With Poorer Outcome in Critically Ill Stroke Patients

Background and Purpose: This study aims to explore the cause and predictive value of hyperchloremia in critically ill stroke patients.

Materials and Methods: We conducted a retrospective study of a prospectively collected database of adult patients with first-ever acute ischemic stroke (AIS) or intracerebral hemorrhage (ICH) admitted to the neurointensive care unit (NICU) of a university-affiliated hospital, between January 2013 and December 2016. Patients were excluded if admitted beyond 72 h from onset, if they required neurocritical care for less than 72 h, and were treated with hypertonic saline within 72 h or had creatinine clearance less than 15 mL/min.

Results: Of 405 eligible patients, the prevalence of hyperchloremia ([Cl⁻] ≥ 110 mmol/L) was 8.6% at NICU admission ([Cl⁻]₀) and 17.0% within 72 h ([Cl⁻]_max). Thirty-eight (9.4%) patients had new-onset hyperchloremia and 110 (27.1%) had moderate increase in chloride (Δ[Cl⁻] ≥ 5 mmol/L; Δ[Cl⁻] = [Cl⁻]_max − [Cl⁻]₀) in the first 72 h after admission, which were found to be determined by the sequential organ failure assessment score in multivariate logistic regression analysis. Neither total fluid input nor cumulative fluid balance had significant association with such chloride disturbance. New-onset hyperchloremia and every 5 mmol/L increment in Δ[Cl⁻] were both associated with increased odds of 30-day mortality and 6-month poor outcome, although no independent significance was found in multivariate models.

Conclusion: Hyperchloremia tends to occur in patients more severely affected by AIS and ICH. Although no independent association was found, new-onset hyperchloremia and every 5 mmol/L increment in Δ[Cl⁻] were related to poorer outcome in critically ill AIS and ICH patients.

Subject terms: clinical studies, intracranial hemorrhage, ischemic stroke, mortality/survival, quality and outcomes.

Postinterventional critical care management of aneurysmal subarachnoid hemorrhage

PURPOSE OF REVIEW

Subarachnoid hemorrhage from a ruptured aneurysm (aSAH) is a complex disorder with the potential to have devastating effects on the brain as well as other organ systems. After more than 3 decades of research, the underlying pathophysiologic mechanisms remain incompletely understood and important questions remain regarding the evaluation and management of these patients. The purpose of this review is to analyze the recent literature and improve our understanding of certain key clinical aspects.

RECENT FINDINGS

Growing body of evidence highlights the usefulness of CT perfusion scans in the diagnosis of vasospasm and delayed cerebral ischemia (DCI). Hypervolemia leads to worse cardiopulmonary outcomes and does not improve DCI. The traditional triple H therapy is falling out of favor with hemodynamic augmentation alone now considered the mainstay of medical management. Randomized controlled trials have shown that simvastatin and intravenous magnesium do not prevent DCI or improve functional outcomes after aneurysmal subarachnoid hemorrhage (aSAH). Emerging data using multimodality monitoring has further advanced our understanding of the pathophysiology of DCI in poor grade aSAH.

SUMMARY

The brief review will focus on the postinterventional care of aSAH patients outlining the recent advances over the past few years.

Update on the Treatment of Spontaneous Intraparenchymal Hemorrhage: Medical and Interventional Management

PURPOSE OF REVIEW

Spontaneous intraparenchymal hemorrhage (IPH) is a prominent challenge faced globally by neurosurgeons, neurologists, and intensivists. Over the past few decades, basic and clinical research efforts have been undertaken with the goal of delineating biologically and evidence-based practices aimed at decreasing mortality and optimizing the likelihood of meaningful functional outcome for patients afflicted with this devastating condition. Here, the authors review the medical and surgical approaches available for the treatment of spontaneous intraparenchymal hemorrhage, identifying areas of recent progress and ongoing research to delineate the scope and scale of IPH as it is currently understood and treated.

RECENT FINDINGS

The approaches to IPH have broadly focused on arresting expansion of hemorrhage using a number of approaches. Recent trials have addressed the effectiveness of rapid blood pressure lowering in hypertensive patients with IPH, with rapid lowering demonstrated to be safe and at least partially effective in preventing hematoma expansion. Hemostatic therapy with platelet transfusion in patients on anti-platelet medications has been recently demonstrated to have no benefit and may be harmful. Hemostasis with administration of clotting complexes has not been shown to be effective in reducing hematoma expansion or improving outcomes although correcting these abnormalities as soon as possible remains good practice until further data are available. Stereotactically guided drainage of IPH with intraventricular hemorrhage (IVH) has been shown to be safe and to improve outcomes. Research on new stereotactic surgical methods has begun to show promise. Patients with IPH should have rapid and accurate diagnosis with neuroimaging with computed tomography (CT) and computed tomography angiography (CTA). Early interventions should include control of hypertension to a systolic BP in the range of 140 mmHg for small hemorrhages without intracranial hypertension with beta blockers or calcium channel blockers, correction of any coagulopathy if present, and assessment of the need for surgical intervention. IPH and FUNC (Functional Outcome in Patients with Primary Intracerebral Hemorrhage) scores should be assessed. Patients should be dispositioned to a dedicated neurologic ICU if available. Patients should be monitored for seizures and intracranial pressure issues. Select patients, particularly those with intraventricular extension, may benefit from evacuation of hematoma with a ventriculostomy or stereotactically guided catheter. Once stabilized, patients should be reassessed with CT imaging and receive ongoing management of blood pressure, cerebral edema, ICP issues, and seizures as they arise. The goal of care for most patients is to regain capacity to receive multidisciplinary rehabilitation to optimize functional outcome.

Association between continuous hyperosmolar therapy and survival in patients with traumatic brain injury - a multicentre prospective cohort study and systematic review

BACKGROUND

Intracranial hypertension (ICH) is a major cause of death after traumatic brain injury (TBI). Continuous hyperosmolar therapy (CHT) has been proposed for the treatment of ICH, but its effectiveness is controversial. We compared the mortality and outcomes in patients with TBI with ICH treated or not with CHT.

METHODS

We included patients with TBI (Glasgow Coma Scale ≤ 12 and trauma-associated lesion on brain computed tomography (CT) scan) from the databases of the prospective multicentre trials Corti-TC, BI-VILI and ATLANREA. CHT consisted of an intravenous infusion of NaCl 20% for 24 hours or more. The primary outcome was the risk of survival at day 90, adjusted for predefined covariates and baseline differences, allowing us to reduce the bias resulting from confounding factors in observational studies. A systematic review was conducted including studies published from 1966 to December 2016.

RESULTS

Among the 1086 included patients, 545 (51.7%) developed ICH (143 treated and 402 not treated with CHT). In patients with ICH, the relative risk of survival at day 90 with CHT was 1.43 (95% CI, 0.99-2.06, p = 0.05). The adjusted hazard ratio for survival was 1.74 (95% CI, 1.36-2.23, p < 0.001) in propensity-score-adjusted analysis. At day 90, favourable outcomes (Glasgow Outcome Scale 4-5) occurred in 45.2% of treated patients with ICH and in 35.8% of patients with ICH not treated with CHT (p = 0.06). A review of the literature including 1304 patients from eight studies suggests that CHT is associated with a reduction of in-ICU mortality (intervention, 112/474 deaths (23.6%) vs. control, 244/781 deaths (31.2%); OR 1.42 (95% CI, 1.04-1.95), p = 0.03, I 2 = 15%).

CONCLUSIONS

CHT for the treatment of posttraumatic ICH was associated with improved adjusted 90-day survival. This result was strengthened by a review of the literature.