Use of hypertonic (3%) saline/acetate infusion in the treatment of cerebral edema: Effect on intracranial pressure and lateral displacement of the brain

Updates in Management of Large Hemispheric Infarct

This review delves into updates in management of large hemispheric infarction (LHI), a condition affecting up to 10% of patients with supratentorial strokes. While traditional management paradigms have endured, recent strides in research have revolutionized the approach to acute therapies, monitoring, and treatment. Notably, advancements in triage methodologies and the application of both pharmacological and mechanical abortive procedures have reshaped the acute care trajectory for patients with LHI. Moreover, ongoing endeavors have sought to refine strategies for the optimal surveillance and mitigation of complications, notably space-occupying mass effect, which can ensue in the aftermath of LHI. By amalgamating contemporary guidelines with cutting-edge clinical trial findings, this review offers a comprehensive exploration of the current landscape of acute and ongoing patient care for LHI, illuminating the evolving strategies that underpin effective management in this critical clinical domain.

Acute Liver Failure Guidelines

Acute liver failure (ALF) is a rare, acute, potentially reversible condition resulting in severe liver impairment and rapid clinical deterioration in patients without preexisting liver disease. Due to the rarity of this condition, published studies are limited by the use of retrospective or prospective cohorts and lack of randomized controlled trials. Current guidelines represent the suggested approach to the identification, treatment, and management of ALF and represent the official practice recommendations of the American College of Gastroenterology. The scientific evidence was reviewed using the Grading of Recommendations, Assessment, Development and Evaluation process to develop recommendations. When no robust evidence was available, expert opinions were summarized using Key Concepts. Considering the variety of clinical presentations of ALF, individualization of care should be applied in specific clinical scenarios.

The Safety of Intravenous Peripheral Administration of 3% Hypertonic Saline: A Systematic Review and Meta-analysis

BACKGROUND AND OBJECTIVES

Three percent hypertonic saline (3% HTS) is used to treat several critical conditions such as severe and symptomatic hyponatremia and increased intracranial pressure. It has been traditionally administered through a central venous catheter (CVC). The avoidance of peripheral intravenous infusion of 3% HTS stems theoretically from the concern about the ability of the peripheral veins to tolerate hyperosmolar infusions. The aim of this systematic review and meta-analysis is to assess the rate of complications associated with the infusion of 3% HTS using peripheral intravenous access.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We conducted a systematic review and meta-analysis to assess the rate of complications related to the peripheral infusion of 3% HTS. We searched several databases for available studies that met the criteria until February 24th, 2022. We included ten studies conducted across three countries examining the incidence of infiltration, phlebitis, venous thrombosis, erythema, and edema. The overall event rate was calculated and transformed using the Freeman-Tukey arcsine method and pooled using the DerSimonian and Laird random-effects model. I ² was used to evaluate heterogeneity. Selected items from Newcastle-Ottawa Scale ¹² were used to assess the risk of bias in each included study.

RESULTS

A total of 1200 patients were reported to have received peripheral infusion of 3% HTS. The analysis showed that peripherally administered 3% HTS has a low rate of complications. The overall incidence of each of the complications was as follows: infiltration 3.3%, (95% C.I. = 1.8-5.1%), phlebitis 6.2% (95% C.I. = 1.1-14.3%), erythema 2.3% (95% C.I. = 0.3-5.4%) edema 1.8% (95% C.I. = 0.0-6.2%) and venous thrombosis 1% (95% C.I. = 0.0-4.8%). There was one incident of venous thrombosis preceded by infiltration resulting from peripheral infusion of 3% HTS.

CONCLUSION

Peripheral administration of 3% HTS is considered a safe and possibly preferred option as it carries a low risk of complications and is a less invasive procedure compared to CVC.

Association of hyperchloremia and acute kidney injury in pediatric patients with moderate and severe traumatic brain injury

PURPOSE

Acute kidney injury (AKI) is an established complication of adult traumatic brain injury (TBI) and known risk factor for mortality. Evidence demonstrates an association between hyperchloremia and AKI in critically ill adults but studies in children are scarce. Given frequent use of hypertonic saline in the management of pediatric TBI, we believe the incidence of hyperchloremia will be high and hypothesize that it will be associated with development of AKI.

METHODS

Single-center retrospective cohort study was completed at an urban, level 1 pediatric trauma center. Children > 40 weeks corrected gestational age and < 21 years of age with moderate or severe TBI (presenting GCS < 13) admitted between January 2016 and December 2021 were included. Primary study outcome was presence of AKI (defined by pediatric Kidney Disease: Improving Global Outcomes criteria) within 7 days of hospitalization and compared between patients with and without hyperchloremia (serum chloride ≥ 110 mEq/L).

RESULTS

Fifty-two children were included. Mean age was 5.75 (S.D. 5.4) years; 60% were male (31/52); and mean presenting GCS was 6 (S.D. 2.9). Thirty-seven patients (71%) developed hyperchloremia with a mean peak chloride of 125 (S.D. 12.0) mEq/L and mean difference between peak and presenting chloride of 16 (S.D. 12.7) mEq/L. Twenty-three patients (44%) developed AKI; of those with hyperchloremia, 62% (23/37) developed AKI, while among those without hyperchloremia, 0% (0/15) developed AKI (difference 62%, 95% CI 42-82%, p < 0.001). Attributable risk of hyperchloremia leading to AKI was 62.2 (95% CI 46.5-77.8, p = 0.0015).

CONCLUSION

Hyperchloremia is common in the management of pediatric TBI and is associated with development of AKI. Risk appears to be associated with both the height of serum chloride and duration of hyperchloremia.

Management of Severe Traumatic Brain Injury in Pediatric Patients

The optimal management of severe traumatic brain injury (TBI) in the pediatric population has not been well studied. There are a limited number of research articles studying the management of TBI in children. Given the prevalence of severe TBI in the pediatric population, it is crucial to develop a reference TBI management plan for this vulnerable population. In this review, we seek to delineate the differences between severe TBI management in adults and children. Additionally, we also discuss the known molecular pathogenesis of TBI. A better understanding of the pathophysiology of TBI will inform clinical management and development of therapeutics. Finally, we propose a clinical algorithm for the management and treatment of severe TBI in children using published data.

Early hyperchloremia and outcomes after acute ischemic stroke

OBJECTIVE

Based on the relationship between hyperchloremia and mortality in critically ill patients, we investigated the effect of early hyperchloremia on 90-day outcomes in acute ischemic stroke patients.

MATERIALS AND METHODS

Acute ischemic stroke patients recruited within 5 h of symptom onset were analyzed. Hyperchloremia (defined as 110 mmol/L or greater) at either baseline, or 24, or 48 h after randomization was identified and classified as one occurrence or two or more occurrences. Logistic regression analyses were performed to determine the effects of hyperchloremia on: favorable outcomes (defined by a National Institutes of Health Stroke Scale and/or modified Rankin scale scores of 0-1) at 90-day, death or disability at 90-day, and death within 90-day after accounting for potential confounders.

RESULTS

Among the total of 1275 patients, one and two or more occurrence of hyperchloremia within 48 h were seen in 191 patients and 108 patients, respectively. Compared with patients without hyperchloremia, patients with two or more occurrences of hyperchloremia at significantly higher odds of lack of favorable outcomes (odds ratio 3.0, 95% confidence interval 1.8-5.1) and death or disability (odds ratio 2.6, 95% confidence interval 1.6-4.1) at 90-day after adjustment for age, National Institutes of Health Stroke Scale score strata (6-9, 10-19, ≥ 20), study intervention, initial SBP, and intra-arterial treatment.

CONCLUSIONS

The independent association between sustained hyperchloremia and lack of favorable outcomes at 90-day suggest that avoidance of hyperchloremia may reduce the rate of lack of favorable outcomes and death or disability in patients with acute ischemic stroke.

Effectiveness of Continuous Hypertonic Saline in Acute Ischemic Infarcts: A Radiographic and Clinical Evaluation

OBJECTIVE

The role of continuous hypertonic saline (HS) infusion in the management of malignant cerebral edema is controversial. We evaluated patients presenting with large anterior circulation territory infarcts and compared radiographic and clinical outcomes to evaluate the effects of continuous HS.

METHODS

This was a retrospective review of patients with malignant ischemic strokes who were initially managed with continuous HS versus routine medical management. Radiographic parameters of cerebral edema and clinical parameters were collected at different time intervals after admission. Rates and timing of surgery, mortality, and complications were also collected.

RESULTS

The study included 43 patients: 26 in group 1 (HS) and 17 in group 2 (no HS). Both cohorts had comparable baseline clinical and radiographic parameters. There was no difference between rates and timing of surgery, complications, and mortality. Mean midline shift was significantly greater in the HS group at interval 1 (12-36 hours, P = 0.003) and interval 2 (36-60 hours, P = 0.030), and mean change in midline shift from initial interval to interval 1 was significantly greater in the HS group (P = 0.019).

CONCLUSIONS

Despite the widespread use of continuous HS in acute ischemic infarcts, only a limited number of studies have evaluated its efficacy, and virtually no studies have studied its effect on radiographic progression and rates of decompressive surgery. Results of this study indicate that there is no benefit of continuous HS. In fact, there may be worsening of cerebral edema with administration of continuous HS. In addition, there are no differences in prevention or delay of decompressive surgery or in overall mortality.

Traumatic Brain Injury-A Review of Intravenous Fluid Therapy

This manuscript will review intravenous fluid therapy in traumatic brain injury. Both human and animal literature will be included. Basic treatment recommendations will also be discussed.

What is the Role of Hyperosmolar Therapy in Hemispheric Stroke Patients?

The role of hyperosmolar therapy (HT) in large hemispheric ischemic or hemorrhagic strokes remains a controversial issue. Past and current stroke guidelines state that it represents a reasonable therapeutic measure for patients with either neurological deterioration or intracranial pressure (ICP) elevations documented by ICP monitoring. However, the lack of evidence for a clear effect of this therapy on radiological tissue shifts and clinical outcomes produces uncertainty with respect to the appropriateness of its implementation and duration in the context of radiological mass effect without clinical correlates of neurological decline or documented elevated ICP. In addition, limited data suggest a theoretical potential for harm from the prophylactic and protracted use of HT in the setting of large hemispheric lesions. HT exerts effects on parenchymal volume, cerebral blood volume and cerebral perfusion pressure which may ameliorate global ICP elevation and cerebral blood flow; nevertheless, it also holds theoretical potential for aggravating tissue shifts promoted by significant interhemispheric ICP gradients that may arise in the setting of a large unilateral supratentorial mass lesion. The purpose of this article is to review the literature in order to shed light on the effects of HT on brain tissue shifts and clinical outcome in the context of large hemispheric strokes, as well as elucidate when HT should be initiated and when it should be avoided.

Hypertonic saline buffered with sodium acetate for intracranial pressure management

BACKGROUND

3 % hypertonic saline (HS) is a hyperosmolar agent often used to treat elevated intracranial pressure (ICP). However, the resultant hyperchloremia is associated with adverse outcomes in certain patient populations. In this study, HS solution buffered with sodium acetate (HSwSA) is used as an alternative to standard 3 % formulations to reduce overall chloride exposure. Our objectives are to establish whether this alternative agent - with reduced chloride content - is similar to standard 3 % HS in maintaining hyperosmolarity and investigate its effects on hyperchloremia.

METHODS

A retrospective chart review was conducted from August 1, 2014 to August 1, 2017 on patients receiving hypertonic therapies for ICP management. Patients were categorized into three groups, those that received: (1) 3 % HS for at least 72 h, (2) HSwSA for at least 72 h, or (3) were switched from 3 % HS within 72 h of initiating therapy to HSwSA for at least 72 h.

RESULTS

The average increase in serum osmolality after 72 h of therapy was 21.1 moSm/kg for those only on 3 % HS and 20.3 mOsm/kg for those only on HSwSA. Serum chloride levels after 24 h decreased on average by 2.5 mEq/L after switching from 3% HS to HSwSA and stayed below baseline, whereas matched patients only receiving 3% HS on average had serum chloride levels increase 4.3 mEq/L after 24 h and continued to rise.

CONCLUSIONS

Hyperchloremia has been associated with decreased renal perfusion, increasing the risk of acute kidney injury and hyperchloremic metabolic acidosis. Compared to standard 3% HS, our findings suggest an alternative hyperosmolar therapy with less chloride maintains similar hyperosmolarity while reducing overall chloride exposure.

Guidelines for the Acute Treatment of Cerebral Edema in Neurocritical Care Patients

BACKGROUND

Acute treatment of cerebral edema and elevated intracranial pressure is a common issue in patients with neurological injury. Practical recommendations regarding selection and monitoring of therapies for initial management of cerebral edema for optimal efficacy and safety are generally lacking. This guideline evaluates the role of hyperosmolar agents (mannitol, HTS), corticosteroids, and selected non-pharmacologic therapies in the acute treatment of cerebral edema. Clinicians must be able to select appropriate therapies for initial cerebral edema management based on available evidence while balancing efficacy and safety.

METHODS

The Neurocritical Care Society recruited experts in neurocritical care, nursing, and pharmacy to create a panel in 2017. The group generated 16 clinical questions related to initial management of cerebral edema in various neurological insults using the PICO format. A research librarian executed a comprehensive literature search through July 2018. The panel screened the identified articles for inclusion related to each specific PICO question and abstracted necessary information for pertinent publications. The panel used GRADE methodology to categorize the quality of evidence as high, moderate, low, or very low based on their confidence that the findings of each publication approximate the true effect of the therapy.

RESULTS

The panel generated recommendations regarding initial management of cerebral edema in neurocritical care patients with subarachnoid hemorrhage, traumatic brain injury, acute ischemic stroke, intracerebral hemorrhage, bacterial meningitis, and hepatic encephalopathy.

CONCLUSION

The available evidence suggests hyperosmolar therapy may be helpful in reducing ICP elevations or cerebral edema in patients with SAH, TBI, AIS, ICH, and HE, although neurological outcomes do not appear to be affected. Corticosteroids appear to be helpful in reducing cerebral edema in patients with bacterial meningitis, but not ICH. Differences in therapeutic response and safety may exist between HTS and mannitol. The use of these agents in these critical clinical situations merits close monitoring for adverse effects. There is a dire need for high-quality research to better inform clinicians of the best options for individualized care of patients with cerebral edema.

An overview of management of intracranial hypertension in the intensive care unit

Intracranial hypertension (IH) is a clinical condition commonly encountered in the intensive care unit, which requires immediate treatment. The maintenance of normal intracranial pressure (ICP) and cerebral perfusion pressure in order to prevent secondary brain injury (SBI) is the central focus of management. SBI can be detected through clinical examination and invasive and non-invasive ICP monitoring. Progress in monitoring and understanding the pathophysiological mechanisms of IH allows the implementation of targeted interventions in order to improve the outcome of these patients. Initially, general prophylactic measures such as patient's head elevation, fever control, adequate analgesia and sedation depth should be applied immediately to all patients with suspected IH. Based on specific indications and conditions, surgical resection of mass lesions and cerebrospinal fluid drainage should be considered as an initial treatment for lowering ICP. Hyperosmolar therapy (mannitol or hypertonic saline) represents the cornerstone of medical treatment of acute IH while hyperventilation should be limited to emergency management of life-threatening raised ICP. Therapeutic hypothermia could have a possible benefit on outcome. To control elevated ICP refractory to maximum standard medical and surgical treatment, at first, high-dose barbiturate administration and then decompressive craniectomy as a last step are recommended with unclear and probable benefit on outcomes, respectively. The therapeutic strategy should be based on a staircase approach and be individualized for each patient. Since most therapeutic interventions have an uncertain effect on neurological outcome and mortality, future research should focus on both studying the long-term benefits of current strategies and developing new ones.

Low-chloride- versus high-chloride-containing hypertonic solution for the treatment of subarachnoid hemorrhage-related complications: The ACETatE (A low ChloriE hyperTonic solution for brain Edema) randomized trial

BACKGROUND

Recent reports have demonstrated that among patients with subarachnoid hemorrhage (SAH) treated with hypertonic NaCl, resultant hyperchloremia has been associated with the development of acute kidney injury (AKI). We report a trial comparing the effect of two hypertonic solutions with different chloride contents on the resultant serum chloride concentrations in SAH patients, with a primary outcome aimed at limiting chloride elevation.

METHODS

A low ChloridE hyperTonic solution for brain Edema (ACETatE) trial is a single-center, double-blinded, double-dummy, randomized pilot trial comparing bolus infusions of 23.4% NaCl and 16.4% NaCl/Na-acetate for the treatment of cerebral edema in patients with SAH. Randomization occurred when patients developed hyperchloremia (serum Cl- ≥ 109 mmol/L) and required hyperosmolar treatment.

RESULTS

We enrolled 59 patients, of which 32 developed hyperchloremia and required hyperosmolar treatment. 15 patients were randomized to the 23.4% NaCl group, and 17 patients were randomized to the 16.4% NaCl/Na-acetate group. Although serum chloride levels increased similarly in both groups, the NaCl/Acetate group showed a significantly lower Cl- load at the end of the study period (978mEq vs. 2,464mEq, p < 0.01). Secondary outcome analysis revealed a reduced rate of AKI in the Na-acetate group (53.3% in the NaCl group vs. 11.8% in the Na-acetate group, p = 0.01). Both solutions had similar effects on ICP reduction, but NaCl/Acetate treatment had a more prominent effect on immediate post-infusion Na+ concentrations (increase of 2.2 ± 2.8 vs. 1.4 ± 2.6, (p < 0.01)). Proximal tubule renal biomarkers differed in concentration between the two groups.

CONCLUSIONS

Our pilot trial showed the feasibility and safety of replacing 23.4% NaCl infusions with 16.4% NaCl/Na-acetate infusions to treat cerebral edema in patients with SAH. The degree of hyperchloremia was similar in the two groups. 16.4% NaCl/Na-acetate infusions led to lower Cl- load and AKI rates than 23.4% NaCl infusions. Further multi-center studies are needed to corroborate these results.

TRIAL REGISTRATION

clinicaltrials.gov # NCT03204955, registered on 6/28/2017.

Hyponatremia in the Neurologically Ill Patient: A Review

Hyponatremia is a well-known disorder commonly faced by clinicians managing neurologically ill patients. Neurological disorders are often associated with hyponatremia during their acute presentation and can be associated with specific neurologic etiologies and symptoms. Patients may present with hyponatremia with traumatic brain injury, develop hyponatremia subacutely following aneurysmal subarachnoid hemorrhage, or may manifest with seizures due to hyponatremia itself. Clinicians caring for the neurologically ill patient should be well versed in identifying these early signs, symptoms, and etiologies of hyponatremia. Early diagnosis and treatment can potentially avoid neurologic and systemic complications in these patients and improve outcomes. This review focuses on the causes and findings of hyponatremia in the neurologically ill patient and discusses the pathophysiology, diagnoses, and treatment strategies for commonly encountered etiologies.

The Medical Management of Cerebral Edema: Past, Present, and Future Therapies

Cerebral edema is commonly associated with cerebral pathology, and the clinical manifestation is largely related to the underlying lesioned tissue. Brain edema usually amplifies the dysfunction of the lesioned tissue and the burden of cerebral edema correlates with increased morbidity and mortality across diseases. Our modern-day approach to the medical management of cerebral edema has largely revolved around, an increasingly artificial distinction between cytotoxic and vasogenic cerebral edema. These nontargeted interventions such as hyperosmolar agents and sedation have been the mainstay in clinical practice and offer noneloquent solutions to a dire problem. Our current understanding of the underlying molecular mechanisms driving cerebral edema is becoming much more advanced, with differences being identified across diseases and populations. As our understanding of the underlying molecular mechanisms in neuronal injury continues to expand, so too is the list of targeted therapies in the pipeline. Here we present a brief review of the molecular mechanisms driving cerebral edema and a current overview of our understanding of the molecular targets being investigated.

Real-time Noninvasive Monitoring of Intracranial Fluid Shifts During Dialysis Using Volumetric Integral Phase-Shift Spectroscopy (VIPS): A Proof-of-Concept Study

BACKGROUND

Cerebral edema, which is associated with increased intracranial fluid, is often a complication of many acute neurological conditions. There is currently no accepted method for real-time monitoring of intracranial fluid volume at the bedside. We evaluated a novel noninvasive technique called "Volumetric Integral Phase-shift Spectroscopy (VIPS)" for detecting intracranial fluid shifts during hemodialysis.

METHODS

Subjects receiving scheduled hemodialysis for end-stage renal disease and without a history of major neurological conditions were enrolled. VIPS monitoring was performed during hemodialysis. Serum osmolarity, electrolytes, and cognitive function with mini-mental state examination (MMSE) were assessed.

RESULTS

Twenty-one monitoring sessions from 14 subjects (4 women), mean group age 50 (SD 12.6), were analyzed. The serum osmolarity decreased by a mean of 6.4 mOsm/L (SD 6.6) from pre- to post-dialysis and correlated with an increase in the VIPS edema index (E-Dex) of 9.7% (SD 12.9) (Pearson's correlation r = 0.46, p = 0.037). Of the individual determinants of serum osmolarity, changes in serum sodium level correlated best with the VIPS edema index (Pearson's correlation, r = 0.46, p = 0.034). MMSE scores did not change from pre- to post-dialysis.

CONCLUSIONS

We detected an increase in the VIPS edema index during hemodialysis that correlated with decreased serum osmolarity, mainly reflected by changes in serum sodium suggesting shifts in intracranial fluids.

Cerebral Edema and Elevated Intracranial Pressure

PURPOSE OF REVIEW

This article reviews the management of cerebral edema, elevated intracranial pressure (ICP), and cerebral herniation syndromes in neurocritical care.

RECENT FINDINGS

While corticosteroids may be effective in reducing vasogenic edema around brain tumors, they are contraindicated in traumatic cerebral edema. Mannitol and hypertonic saline use should be tailored to patient characteristics including intravascular volume status. In patients with traumatic brain injury who are comatose, elevated ICP should be managed with an algorithmic, multitiered treatment protocol to maintain an ICP of 22 mm Hg or less. Third-line ICP treatments include anesthetic agents, induced hypothermia, and decompressive craniectomy. Recent clinical trials have demonstrated that induced hypothermia and decompressive craniectomy are ineffective as early neuroprotective strategies and should be reserved for third-line management of refractory ICP elevation in severe traumatic brain injury. Monitoring for cerebral herniation should include bedside pupillometry in supratentorial space-occupying lesions and recognition of upward herniation in patients with posterior fossa lesions.

SUMMARY

Although elevated ICP, cerebral edema, and cerebral herniation are interrelated, treatments should be based on the distinct pathophysiologic process. Focal lesions resulting in brain compression are primarily managed with surgical decompression, whereas global or multifocal brain injury requires a treatment protocol that includes medical and surgical interventions.

Transitions of Care for Patients with Neurologic Diagnoses Transition from the Intensive Care Unit to the Floor

Transition of care from the intensive care unit to acute care units after critical neurologic injury includes the consideration of a variety of factors to ensure safe and effective care, and promote ongoing neurologic recovery. Assessment of effectiveness of deescalation techniques, agitation management, and risk factor mitigation are important strategies to enhance the success of transitions. Clear and consistent interdisciplinary communication between teams during hand-off between units is imperative to decrease the risk of complications and errors, and to streamline discharge processes.

The Effects of Induction and Treatment of Intracranial Hypertension on Cerebral Autoregulation: An Experimental Study

Background

This study aimed to analyse cerebral autoregulation (CA) during induction and treatment of intracranial hypertension (ICH) in an experimental model.

Materials and Methods

Landrace and Duroc piglets were divided into mild and severe ICH groups. Four or seven millilitres of saline solution was infused into paediatric bladder catheter inserted in the parietal lobe (balloon inflation). After 1.5 h, a 3% saline solution was infused via venous catheter, and 30 min later, the bladder catheter balloon was deflated (surgery). The cerebral static autoregulation (sCA) index was evaluated using cerebral blood flow velocities (CBFV) obtained with Doppler ultrasound.

Results

Balloon inflation increased ICP in both groups. The severe ICH group showed significantly lower sCA index values (p=0.001, ANOVA) after balloon inflation (ICH induction) and a higher sCA index after saline injection (p=0.02) and after surgery (p=0.04). ICP and the sCA index were inversely correlated (r=-0.68 and p<0.05). CPP and the sCA index were directly correlated (r=0.74 and p<0.05).

Conclusion

ICH was associated with local balloon expansion, which triggered CA impairment, particularly in the severe ICH group. Moreover, ICP-reducing treatments were associated with improved CA in subjects with severe ICH.

Association between continuous peripheral i.v. infusion of 3% sodium chloride injection and phlebitis in adults

PURPOSE

One institution's experience with use of peripheral i.v. (PIV) catheters for prolonged infusions of 3% sodium chloride injection at rates up to 100 mL/hr is described.

METHODS

A prospective, observational, 13-month quality assurance project was conducted at an academic medical center to evaluate frequencies of patient and catheter phlebitis among adult inpatients who received both an infusion of 3% sodium chloride injection for a period of ≥4 hours through a dedicated PIV catheter and infusions of routine-care solutions (RCSs) through separate PIV catheters during the same hospital stay.

RESULTS

Sixty patients received PIV infusions through a total of 291 catheters during the study period. The majority of patients (78%) received infusions of 3% sodium chloride injection for intracranial hypertension, with 30% receiving such infusions in the intensive care unit. Phlebitis occurred in 28 patients (47%) during infusions of 3% sodium chloride and 26 patients (43%) during RCS infusions (p = 0.19). Catheter phlebitis occurred in 73 catheters (25%), with no significant difference in the frequencies of catheter phlebitis with infusion of 3% sodium chloride versus RCSs (30% [32 of 106 catheters]) versus 22% [41 of 185 catheters]), p = 0.16).

CONCLUSION

Patient and catheter phlebitis rates were not significantly different with infusions of 3% sodium chloride injection versus RCSs, suggesting that an osmolarity cutoff value of 900 mOsm/L for peripheral infusions of hypertonic saline solutions may not be warranted.

Hypertonic saline infusion for treating intracranial hypertension after severe traumatic brain injury

Traumatic brain injury (TBI) remains a major cause of mortality and disability. Post-traumatic intracranial hypertension (ICH) further complicates the care of patients. Hyperosmolar agents are recommended for the treatment of ICH, but no consensus or high-level data exist on the use of any particular agent or the route of administration. The two agents used commonly are hypertonic saline (HTS) and mannitol given as bolus therapy. Smaller studies suggest that HTS may be a superior agent in reducing the ICH burden, but neither agent has been shown to improve mortality or functional outcome. In a recently published analysis of pooled data from three prospective clinical trials, continuous infusion of HTS correlated with serum hypernatremia and reduced ICH burden in addition to improving 90-day mortality and functional outcome. This lays the foundation for the upcoming continuous hyperosmolar therapy for traumatic brain-injured patients (COBI) randomized controlled trial to study the outcome benefit of continuous HTS infusion to treat ICH after severe TBI. This is much anticipated and will be a high impact trial should the results be replicated. However, this would still leave a question over the use of mannitol bolus therapy which will need to be studied.

The association between intensive care unit-acquired hypernatraemia and mortality in critically ill patients with cerebrovascular diseases: a single-centre cohort study in Japan

OBJECTIVES

Hypernatraemia is one of the major electrolyte disorders associated with mortality among critically ill patients in intensive care units (ICUs). It is unclear whether this applies to patients with cerebrovascular diseases in whom high sodium concentrations may be allowed in order to prevent cerebral oedema. This study aimed to examine the association between ICU-acquired hypernatraemia and the prognosis of patients with cerebrovascular diseases.

DESIGN

A retrospective cohort study.

SETTING

The incidence of ICU-acquired hypernatraemia was assessed retrospectively in a single tertiary care facility in Japan.

PARTICIPANTS

Adult patients (≥18 years old) whose length of stay in ICU was >2 days and those whose serum sodium concentrations were 130-149 mEq/L on admission to ICU were included.

OUTCOME MEASURES

28-day in-hospital mortality risk was assessed by Cox regression analysis. Hypernatraemia was defined as serum sodium concentration ≥150 mEq/L. Using multivariate analysis, we examined whether ICU-acquired hypernatraemia and the main symptom present at ICU admission were associated with time to death among ICU patients. We also evaluated how the maximum and minimum sodium concentrations during ICU stay were associated with mortality, using restricted cubic splines.

RESULTS

Of 1756 patients, 121 developed ICU-acquired hypernatraemia. Multivariate Cox proportional hazard analysis revealed an association between ICU-acquired hypernatraemia and 28-day mortality (adjusted HR, 3.07 (95% CI 2.12 to 4.44)). The interaction between ICU-acquired hypernatraemia and cerebrovascular disease was significantly associated with 28-day mortality (HR, 3.03 (95% CI 1.29 to 7.15)). The restricted cubic splines analysis of maximum serum sodium concentration in ICU patients determined a threshold maximum of 147 mEq/L. There was no significant association between minimum sodium concentration and mortality.

CONCLUSIONS

ICU-acquired hypernatraemia was associated with an increased mortality rate among critically ill patients with cerebrovascular diseases; the threshold maximum serum sodium concentration associated with mortality was 147 mEq/L.

The Use of Mannitol and Hypertonic Saline Therapies in Patients with Elevated Intracranial Pressure: A Review of the Evidence

Patients with increased intracranial pressure generally require pharmacologic therapies and often more definitive treatments, such as surgical intervention. The overall goal of these interventions is to maintain or re-establish adequate cerebral blood flow and prevent herniation. Regardless of the cause of increased intracranial pressure, osmotherapy is considered the mainstay of medical therapy, and should be administered as soon as possible. This article reviews the history of hyperosmolar and hypertonic therapies, the Monro-Kellie hypothesis, and types of cerebral edema. Pharmacologic properties, clinical applications, complications, recommended monitoring during therapy, and risks versus benefits are also discussed.

Analyzing the efficacy of frequent sodium checks during hypertonic saline infusion after elective brain tumor surgery

OBJECTIVE

To assess the utility of frequent sodium checks (every 6h) in patients receiving hypertonic saline (HS) after elective brain tumor surgeries.

PATIENTS AND METHODS

A single-institution retrospective review of patients having undergone elective craniotomies for brain tumors and treated with postoperative continuous intravenous infusions of 3% HS was performed. Changes in serum sodium values were analyzed at different time points. The rates of <12.5, 25, and 50cc/h infusions were also examined. Healthcare cost analysis was performed by extrapolating our cohort to the total number of craniotomies performed in the United States.

RESULTS

No significant differences among sodium values checked between 0 to 4, 4-6, 6-8, 8-10, and >10h were observed (P=.64). In addition, no differences in serum sodium values among the rates of <12.5, 25, and 50cc/h were found (P=.30). No patients developed symptoms of acute hypernatremia.

CONCLUSIONS

Serum sodium values did not significantly change more than 10h after infusion of HS. Further studies are needed to determine the optimal frequency of routine sodium checks to increase the quality of care and decrease healthcare costs.

Emergency anesthesia for evacuating a traumatic acute subdural hemorrhage in a child overdosed with hypertonic saline

A previously healthy 1-year-old child with a traumatic acute subdural hemorrhage received 10 times higher dose of hypertonic saline inadvertently immediately before surgery. This case report describes deviations in fluid management needed to alleviate salt toxicity and its adverse effects during surgery under anesthesia perioperatively. The child made an uneventful recovery with no evident residual damage at follow-up.

Predictors of Acute Kidney Injury in Neurocritical Care Patients Receiving Continuous Hypertonic Saline

BACKGROUND AND PURPOSE

Continuous intravenous 3% hypertonic saline (HTS) infusions are commonly used for the management of cerebral edema following severe neurologic injuries. Despite widespread use, data regarding the incidence and predictors of nephrotoxicity are lacking. The purpose of this study was to describe the incidence and identify predictors of acute kidney injury (AKI) in neurocritical care patients administered continuous infusion HTS.

METHODS

This was an institutional review board-approved, multicenter, retrospective cohort study of patients receiving HTS infusions at 2 academic medical centers. A univariate analysis and multivariable logistic regression were used to identify predictors of AKI. Data regarding AKI were evaluated during treatment with HTS and up to 24 hours after discontinuation.

RESULTS

A total of 329 patients were included in our analysis, with 54 (16%) developing AKI. Those who developed AKI experienced significantly longer stays in the intensive care unit (14.8 vs 11.5 days; P = .006) and higher mortality (48.1% vs 21.9%; P < .001). We identified past medical history of chronic kidney disease (odds ratio [OR]: 9.7, 95% confidence interval [CI]: 1.9-50.6; P = .007), serum sodium greater than 155 mmol/L (OR: 4.1, 95% CI: 2.1-8.0; P < .001), concomitant administration of piperacillin/tazobactam (OR: 3.9, 95% CI: 1.7-9.3; P = .002), male gender (OR: 3.2, 95% CI: 1.5-6.6; P = .002), and African American race (OR: 2.6, 95% CI: 1.3-5.2; P = .007) as independent predictors of AKI.

CONCLUSION

Acute kidney injury is relatively common in patients receiving continuous HTS and may significantly impact clinical outcomes.

Today's Approach to Treating Brain Swelling in the Neuro Intensive Care Unit

Brain swelling is an urgent clinical problem that frequently accompanies ischemic stroke, brain hemorrhage, and traumatic brain injury; it increases morbidity and mortality associated with them. It occurs due to failure of membrane transporters and leakage of the blood-brain barrier (BBB), resulting in combination of cytotoxic, ionic, and vasogenic edema. Currently, decompressive craniectomy and osmotherapy are the mainstays of management, but these therapies do not halt the underlying molecular cascade leading to brain swelling. Recent advances in the molecular underpinnings of cerebral edema have opened up possibilities of newer targeted therapeutic options. Here the authors outline the current approach for rapid diagnosis and intervention to reduce mortality and morbidity associated with brain swelling.

The Reduction Rate of Serum Sodium and Mortality in Patients Undergoing Continuous Venovenous Hemofiltration for Acute Severe Hypernatremia

BACKGROUND

The excessive correction of acute hypernatremia is not known to be harmful. This study aimed to evaluate whether a reduction rate of serum sodium (RRSeNa) > 1mEq/L/hour in acute severe hypernatremia is an independent risk factor for mortality in critically ill patients undergoing continuous venovenous hemofiltration (CVVH) treatment.

MATERIALS AND METHODS

For this retrospective study, we reviewed records of 75 critically ill patients undergoing CVVH treatment for acute severe hypernatremia between March 2011 and March 2015.

RESULTS

The 28-day mortality rate of all patients was 61.3%. In multivariate Cox regression analyses, a reduction rate of serum sodium (RRSeNa) > 1mEq/L/hour (hazard ratio = 1.89; 95% CI: 1.03-3.47; P = 0.04), Acute Physiology and Chronic Health Evaluation II score and vasopressor dependency (yes or no) had a statistically significantly effect on mortality. Once we excluded patients with an RRSeNa ≤ 0.5mEq/L/hour, only RRSeNa > 1mEq/L/hour (hazard ratio = 2.611; 95% CI: 1.228-5.550; P = 0.013) and vasopressor dependency had a statistically significant influence on mortality in multivariate regression.

CONCLUSIONS

In addition to the Acute Physiology and Chronic Health Evaluation II score and vasopressor dependency, the excessive correction of acute severe hypernatremia was possibly associated with mortality in critically ill patients undergoing CVVH treatment. The optimal reduction rate of acute hypernatremia should be extensively studied in critically ill patients.

Management of Elevated Intracranial Pressure

Elevated intracranial pressure (ICP) is a primary cause of morbidity and mortality for many neurologic disorders. The relationship between ICP and brain volume is influenced by autoregulatory processes that can become dysfunctional. As a result, neurologic damage can occur by systemic and intracranial insults such as ischemia and excitatory amino acids. Therefore, survival is dependent on optimizing ICP and cerebral perfusion pressure. Treatment of intracranial hypertension requires intensive monitoring and aggressive therapy. Intracranial pressure monitoring techniques such as intraventricular catheters are useful for determining ICP elevations before changes in vital signs and neurologic status. Therapeutic modalities, generally aimed at reducing cerebral blood volume, brain tissue, and cerebrospinal fluid (CSF) volume, include nonpharmacologic (CSF removal, controlled hyperventilation, and elevating the patient’s head) and pharmacologic management. Mannitol and sedation are first-line agents used to lower ICP. Barbiturate coma may be beneficial in patients with elevated ICP refractory to conventional treatment. The use of prophylactic antiseizure therapy and optimal nutrition prevents significant complication. Currently, investigations are directed at discovering useful neuroprotective agents that prevent secondary neurologic injury.

Critical Care Management of Increased Intracranial Pressure

Increased intracranial pressure (ICP) is a pathologic state common to a variety of serious neurologic conditions, all of which are characterized by the addition of volume to the intracranial vault. Hence all ICP therapies are directed toward reducing intracranial volume. Elevated ICP can lead to brain damage or death by two principle mechanisms: (1) global hypoxic-ischemic injury, which results from reduction of cerebral perfusion pressure (CPP) and cerebral blood flow, and (2) mechanical compression, displacement, and herniation of brain tissue, which results from mass effect associated with compartmentalized ICP gradients. In unmonitored patients with acute neurologic deterioration, head elevation (30 degrees), hyperventilation (pCO2 26-30 mmHg), and mannitol (1.0-1.5 g/kg) can lower ICP within minutes. Fluid-coupled ventricular catheters and intraparenchymal pressure transducers are the most accurate and reliable devices for measuring ICP in the intensive care unit (ICU) setting. In a monitored patient, treatment of critical ICP elevation (>20 mmHg) should proceed in the following steps: (1) consideration of repeat computed tomography (CT) scanning or consideration of definitive neurosurgical intervention, (2) intravenous sedation to attain a quiet, motionless state, (3) optimization of CPP to levels between 70 and 110 mmHg, (4) osmotherapy with mannitol or hypertonic saline, (5) hyperventilation (pCO2 26-30 mmHg), (6) high-dose pentobarbital therapy, and (7) systemic cooling to attain moderate hypothermia (32-33°C). Placement of an ICP monitor and use of a stepwise treatment algorithm are both essential for managing ICP effectively in the ICU setting.

Definition, evaluation, and management of brain relaxation during craniotomy

The term 'brain relaxation' is routinely used to describe the size and firmness of the brain tissue during craniotomy. The status of brain relaxation is an important aspect of neuroanaesthesia practice and is relevant to the operating conditions, retraction injury, and likely patient outcomes. Brain relaxation is determined by the relationship between the volume of the intracranial contents and the capacity of the intracranial space (i.e. a content-space relationship). It is a concept related to, but distinct from, intracranial pressure. The evaluation of brain relaxation should be standardized to facilitate clinical communication and research collaboration. Both advantageous and disadvantageous effects of the various interventions for brain relaxation should be taken into account in patient care. The outcomes that matter the most to patients should be emphasized in defining, evaluating, and managing brain relaxation. To date, brain relaxation has not been reviewed specifically, and the aim of this manuscript is to discuss the current approaches to the definition, evaluation, and management of brain relaxation, knowledge gaps, and targets for future research.

The effect of continuous hypertonic saline infusion and hypernatremia on mortality in patients with severe traumatic brain injury: a retrospective cohort study

PURPOSE

Hypertonic saline (HTS) is used to control intracranial pressure (ICP) in patients with traumatic brain injury (TBI); however, in prior studies, the resultant hypernatremia has been associated with increased mortality. We aimed to study the effect of HTS on ICP and mortality in patients with severe TBI.

METHODS

We performed a retrospective cohort study of 231 patients with severe TBI (Glasgow Coma Scale [GCS] ≤ 8) admitted to two neurotrauma units from 2006-2012. We recorded daily HTS, ICP, and serum sodium (Na) concentration. We used Cox proportional regression modelling for hospital mortality and incorporated the following time-dependent variables: use of HTS, hypernatremia, and desmopressin administration.

RESULTS

The mean [standard deviation (SD)] age of patients was 34 (17) and the median (interquartile range [IQR]) GCS was 6 [3-8]. Hypertonic saline was administered as a continuous infusion in 124 of 231 (54%) patients over 788 of 2,968 (27%) patient-days. Hypernatremia (Na > 145 mmol·L(-1)) developed in 151 of 231 (65%) patients over 717 of 2,968 (24%) patients-days. In patients who developed hypernatremia, the median [IQR] Na was 146 [142-147] mmol·L(-1). Overall hospital mortality was 26% (59 of 231 patients). After adjusting for baseline covariates, neither HTS (hazard ratio [HR], 1.07; 95% confidence interval [CI], 0.56 to 2.05; P = 0.84) nor hypernatremia (HR, 1.31; 95% CI, 0.68 to 2.55; P = 0.42) was associated with hospital mortality. There was no effect modification by either HTS or hypernatremia on each another. Patients who received HTS observed a significant decrease in ICP during their ICU stay compared with those who did not receive HTS (4 mmHg; 95% CI, 2 to 6; P < 0.001 vs 2 mmHg; 95% CI, -1 to 5; P = 0.14).

CONCLUSIONS

Hypertonic saline and hypernatremia are not associated with hospital mortality in patients with severe TBI.

Therapeutic Hypothermia Reduces Intracranial Pressure and Partial Brain Oxygen Tension in Patients with Severe Traumatic Brain Injury: Preliminary Data from the Eurotherm3235 Trial

Traumatic brain injury (TBI) is a significant cause of disability and death and a huge economic burden throughout the world. Much of the morbidity associated with TBI is attributed to secondary brain injuries resulting in hypoxia and ischemia after the initial trauma. Intracranial hypertension and decreased partial brain oxygen tension (PbtO2) are targeted as potentially avoidable causes of morbidity. Therapeutic hypothermia (TH) may be an effective intervention to reduce intracranial pressure (ICP), but could also affect cerebral blood flow (CBF). This is a retrospective analysis of prospectively collected data from 17 patients admitted to the Western General Hospital, Edinburgh. Patients with an ICP >20 mmHg refractory to initial therapy were randomized to standard care or standard care and TH (intervention group) titrated between 32°C and 35°C to reduce ICP. ICP and PbtO2 were measured using the Licox system and core temperature was recorded through rectal thermometer. Data were analyzed at the hour before cooling, the first hour at target temperature, 2 consecutive hours at target temperature, and after 6 hours of hypothermia. There was a mean decrease in ICP of 4.3±1.6 mmHg (p<0.04) from 15.7 to 11.4 mmHg, from precooling to the first epoch of hypothermia in the intervention group (n=9) that was not seen in the control group (n=8). A decrease in ICP was maintained throughout all time periods. There was a mean decrease in PbtO2 of 7.8±3.1 mmHg (p<0.05) from 30.2 to 22.4 mmHg, from precooling to stable hypothermia, which was not seen in the control group. This research supports others in demonstrating a decrease in ICP with temperature, which could facilitate a reduction in the use of hyperosmolar agents or other stage II interventions. The decrease in PbtO2 is not below the suggested treatment threshold of 20 mmHg, but might indicate a decrease in CBF.

Options for managing raised intracranial pressure

This article reviews the current monitoring and management options for raised intracranial pressure (ICP), primarily in traumatic head injuries, in line with current literature and guidelines. The use of ICP monitoring is useful in managing, predicting outcomes, following the progression and guiding interventions of neurological disease states.

Patients with raised ICP should be monitored closely in a neurocritical care setting where appropriate interventions can be instituted based on available monitoring parameters. Various first- and second-tier methods should be considered, with the primary goal to decrease secondary insult to brain tissue for best outcomes.

Efficacy and Safety of Continuous Micro-Pump Infusion of 3% Hypertonic Saline combined with Furosemide to Control Elevated Intracranial Pressure

Background

Elevated intracranial pressure is one of the most common problems in patients with diverse intracranial disorders, leading to increased morbidity and mortality. Effective management for increased intracranial pressure is based mainly on surgical and medical techniques with hyperosmolar therapy as one of the core medical treatments. The study aimed to explore the effects of continuous micro-pump infusions of 3% hypertonic saline combined with furosemide on intracranial pressure control.

Material/Methods

We analyzed data on 56 eligible participants with intracranial pressure >20 mmHg from March 2013 to July 2014. The target was to increase and maintain plasma sodium to a level between 145 and 155 mmol/L and osmolarity to a level of 310 to 320 mOsmol/kg.

Results

Plasma sodium levels significantly increased from 138±5 mmol/L at admission to 151±3 mmol/L at 24 h (P<0.01). Osmolarity increased from 282±11 mOsmol/kg at baseline to 311±8 mOsmol/kg at 24 h (P<0.01). Intracranial pressure significantly decreased from 32±7 mmHg to 15±6 mmHg at 24 h (P<0.01). There was a significant improvement in CPP (P<0.01). Moreover, central venous pressure, mean arterial pressure, and Glasgow Coma Scale slightly increased. However, these changes were not statistically significant.

Conclusions

Continuous infusion of 3% hypertonic saline + furosemide is effective and safe for intracranial pressure control.

Hypertonic saline for the treatment of intracranial hypertension

Intracranial hypertension is caused by brain edema generated by different disorders, the commonest of which is traumatic brain injury. The treatment of brain edema focuses on drawing water out of brain tissue into the intravascular space. This is typically accomplished with osmolar therapy, most commonly mannitol and hypertonic saline. Recent human trials suggest that hypertonic saline may have a more profound and long-lasting effect in reducing intracranial hypertension following traumatic brain injury when compared with mannitol. However, reports suffer from inconsistencies in dose, frequency, concentration, and route of administration. Side effect profile, potential complications, and contraindications to administration need to be factored in when considering which first-line osmotherapy to choose for a given patient with head injury.

Post-traumatic multimodal brain monitoring: response to hypertonic saline

Emerging evidence suggests that hypertonic saline (HTS) is efficient in decreasing intracranial pressure (ICP). However there is no consensus about its interaction with brain hemodynamics and oxygenation. In this study, we investigated brain response to HTS bolus with multimodal monitoring after severe traumatic brain injury (TBI). We included 18 consecutive TBI patients during 10 days after neurocritical care unit admission. Continuous brain monitoring applied included ICP, tissue oxygenation (PtO2) and cerebral blood flow (CBF). Cerebral perfusion pressure (CPP), cerebrovascular resistance (CVR), and reactivity indices related to pressure (PRx) and flow (CBFx) were calculated. ICM+software was used to collect and analyze monitoring data. Eleven of 18 (61%) patients developed 99 episodes of intracranial hypertension (IHT) greater than 20 mm Hg that were managed with 20% HTS bolus. Analysis over time was performed with linear mixed-effects regression modelling. After HTS bolus, ICP and CPP improved over time (p<0.001) following a quadratic model. From baseline to 120 min, ICP had a mean decrease of 6.2 mm Hg and CPP a mean increase of 3.1 mmHg. Mean increase in CBF was 7.8 mL/min/100 g (p<0.001) and mean decrease in CVR reached 0.4 mm Hg*min*100 g/mL (p=0.01). Both changes preceded pressures improvement. PtO2 exhibited a marginal increase and no significant models for time behaviour could be fitted. PRx and CBFx were best described by a linear decreasing model showing autoregulation recover after HTS (p=0.01 and p=0.04 respectively). During evaluation, CO2 remained constant and sodium level did not exhibit significant variation. In conclusion, management of IHT with 20% HTS significantly improves cerebral hemodynamics and cerebrovascular reactivity with recovery of CBF appearing before rise in CPP and decrease in ICP. In spite of cerebral hemodynamic improvement, no significant changes in brain oxygenation were identified.

Hyperosmolar and methotrexate therapy avoiding surgery in the acute presentation of primary central nervous system lymphoma

Background:

Primary central nervous system lymphoma (PCNSL) is an aggressive type of extra-nodal non-Hodgkin lymphoma. Without treatment, PCNSL is associated with significant morbidity and mortality, including rapid neurological deterioration. In contrast to other high-grade intracranial neoplasms, PCNSL is considered to have a high response rate to conventional medical therapy, especially in younger patients, and therefore warrants particular attention in terms of nonsurgical treatment.

Case Description:

We report a case of the medical management of acute deterioration due to rapidly growing PCNSL with mass effect to highlight the efficacy of temporization with hyperosmolar therapy while awaiting the known rapid effects of dexamethasone and methotrexate (MTX) treatment. Surgical intervention was avoided, and tumor response was rapid. The patient had corresponding clinical resolution of symptoms of elevated intracranial pressure with return to neurologic baseline.

Conclusions:

Despite the evidence that PCNSL responds well to steroids and MTX, the rapidity of onset with which this occurs can vary. In patients presenting with mass effect and rapid neurologic decline, there is little evidence to support medical over surgical intervention. Herein we present an illustrative case of a large PCNSL lesion presenting with rapid decline. With clinical improvement in one day and a 50% reduction in tumor volume over less than seven days, the authors present the specific time frame with which PCNSL responds to medical therapy and a safe strategy for medical temporization.

Infarct volume after hyperacute infusion of hypertonic saline in a rat model of acute embolic stroke

INTRODUCTION

Hypertonic saline (HS) can treat cerebral edema arising from a number of pathologic conditions. However, physicians are reluctant to use it during the first 24 h after stroke because of experimental evidence that it increases infarct volume when administered early after reperfusion. Here, we determined the effect of HS on infarct size in an embolic clot model without planned reperfusion.

METHODS

A clot was injected into the internal carotid artery of male Wistar rats to reduce perfusion in the middle cerebral artery territory to less than 40 % of baseline, as monitored by laser-Doppler flowmetry. After 25 min, rats were randomized to receive 10 mL/kg of 7.5 % HS (50:50 chloride:acetate) or normal saline (NS) followed by a 0.5 mL/h infusion of the same solution for 22 h.

RESULTS

Infarct volume was similar between NS and HS groups (in mm(3): cortex 102 ± 65 mm(3) vs. 93 ± 49 mm(3), p = 0.72; caudoputamenal complex 15 ± 9 mm(3) vs. 21 ± 14, p = 0.22; total hemisphere 119 ± 76 mm(3) vs. 114 ± 62, p = 0.88, respectively). Percent water content was unchanged in the infarcted hemisphere (NS 81.6 ± 1.5 %; HS 80.7 ± 1.3 %, p = 0.16), whereas the HS-treated contralateral hemisphere was significantly dehydrated (NS 79.4 ± 0.8 %; HS 77.5 ± 0.8 %, p < 0.01).

CONCLUSIONS

HS reduced contralateral hemispheric water content but did not affect ipsilateral brain water content when compared to NS. Infarct volume was unaffected by HS administration at all evaluated locations.

Prehospital neurologic deterioration is independent predictor of outcome in traumatic brain injury: analysis from National Trauma Data Bank

BACKGROUND

The prevalence and impact of prehospital neurologic deterioration (PhND) in patients with traumatic brain injury (TBI) have not been investigated. We aimed to determine the prevalence of PhND during emergency medical service (EMS) transportation among patients with TBI and its impact on patient's outcome.

METHODS

We used the National Trauma Data Bank, using data files from 2009 to 2010 to identify patients with TBI through International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes. The initial Glasgow Coma Scale (GCS) score ascertained at the scene by EMS was compared with the subsequent GCS score evaluation in the emergency department (ED) to identify neurologic deterioration (defined as a decrease in GCS of ≥2 points). Patients' demographics, initial injury severity score (ISS), admission GCS score, and hospital outcome were compared between patients with PhND and patients without neurologic deterioration.

RESULTS

A total of 257 127 patients with TBI were identified. Among patients with TBI, 22 254 patients had PhND, which comprised 9% of all patients with TBI. The mean of GCS score decrease during EMS transport was 5 points (±3). Patients without PhND tended to have higher GCS recorded by EMS (median, 15 vs 12; P < .0001). Patients with TBI who had PhND had significantly higher hospital length of stay and intensive care unit days after adjusting for baseline characteristics and EMS GCS score, EMS transport time, type of injury, presence of intracranial hemorrhages, and ED ISS (P < .0001). These patients had higher rate of in-hospital mortality after adjusting for the same variables (odds ratio, 2.30; 95% confidence interval, 2.18-2.41).

CONCLUSION

Prehospital neurologic deterioration occurs in 9% of patients with TBI. It is more prevalent in men and associated with lower EMS GCS level and higher ED ISS. Prehospital neurologic deterioration is an independent predictor of worse hospital outcome and higher resource use in patients with TBI.

Current purpose and practice of hypertonic saline in neurosurgery: a review of the literature

OBJECTIVE

To review and summarize controversies and current concepts regarding the use of hypertonic saline during the perioperative period in neurosurgery.

METHODS

Relevant literature was searched on PubMed and Scopus electronic databases to identify all studies that have investigated the use of hypertonic saline in neurosurgery.

RESULTS

Fluid management during the course of neurosurgical practice has been debated at length, especially strategies to control intracranial pressure and small volume resuscitation. The goal of fluid therapy includes minimizing cerebral edema, preserving intravascular volume, and maintaining cerebral perfusion pressure. Mannitol is widely recognized as the gold standard for treating intracranial hypertension but can result in systemic hypotension. Thus, hypertonic saline provides volume expansion and may improve cerebral and systemic hemodynamics. Recently published prospective data, however, regarding the use of osmotic agents fails to establish clear guidelines in neurosurgical patients.

CONCLUSIONS

We suggest that hypertonic saline will emerge as an alternative to mannitol, especially for a long-term use or multiple doses are needed and lead to a great opportunity for collaborative research.

Hyperosmolar therapy for intracranial hypertension

The use of hyperosmolar agents for intracranial hypertension was introduced in the early 20th century and remains a mainstay of therapy for patients with cerebral edema. Both animal and human studies have demonstrated the efficacy of two hyperosmolar agents, mannitol and hypertonic saline, in reducing intracranial pressure via volume redistribution, plasma expansion, rheologic modifications, and anti-inflammatory effects. However, because of physician and institutional variation in therapeutic practices, lack of standardized protocols for initiation and administration of therapy, patient heterogeneity, and a paucity of randomized controlled trials have yielded little class I evidence on which clinical decisions can be based, most current evidence regarding the use of hyperosmolar therapy is derived from retrospective analyses (class III) and case series (class IV). In this review, we summarize the available evidence regarding the use of hyperosmolar therapy with mannitol or hypertonic saline for the medical management of intracranial hypertension and present a comprehensive discussion of the evidence associated with various theoretical and practical concerns related to initiation, dosage, and monitoring of therapy.

The relationship between serum sodium and intracranial pressure when using hypertonic saline to target mild hypernatremia in patients with head trauma

INTRODUCTION

Limited data suggest mild hypernatremia may be related to lower intracranial pressure (ICP) in patients with traumatic brain injury (TBI). The practice at the study center has been to use hypertonic saline (HTS) to generate a targeted serum sodium of 145 to 155 mEq/l in patients with TBI. The purpose of this study was to determine the relationship between serum sodium values and ICP, and to evaluate the acute effect of HTS on ICP.

METHODS

A retrospective review of patients who were admitted to the trauma ICU for TBI, had an ICP monitor placed, and received at least one dose of HTS between January 2006 and March 2011 was performed. Data were collected for up to 120 hours after ICP monitor placement. The primary outcome was the relationship between serum sodium and maximum ICP. Secondary outcomes were the relationship between serum sodium and the mean number of daily interventions for ICP control, and the acute effect of HTS on ICP during the 6 hours after each dose. Linear regression was used to analyze the primary outcome. Analysis of variance on ranks and repeated measures analysis of variance were used to evaluate the number of interventions and the acute effect of HTS on ICP, respectively.

RESULTS

Eighty-one patients were enrolled with mean ± standard deviation age of 36 ± 15 years and median Glasgow Coma Scale score of 7 (interquartile range, 4 to 7). A total of 1,230 serum sodium values (range, 118 to 174 mEq/l) and 7,483 ICP values (range, 0 to 159 mmHg) were collected. There was no correlation between serum sodium and maximum ICP (R(2) = 0.0052). The overall mean ± standard deviation number of interventions for elevated ICP per day was 4.2 ± 2.9, 2.9 ± 2.0, and 2.6 ± 2.3 for patients with a mean serum sodium of < 145, 145 to 155, and > 155 mEq/l, respectively (P < 0.001). Regarding the acute effect of HTS on ICP, there was no statistical difference in mean ICP compared with baseline during hours 1 through 6 following HTS doses (baseline, 13.7 ± 8.4 mmHg; hour 1, 13.6 ± 8.3 mmHg; hour 2, 13.5 ± 8.8 mmHg; hour 3, 13.3 ± 8.7 mmHg; hour 4, 13.4 ± 8.7 mmHg; hour 5, 13.4 ± 8.3 mmHg; hour 6, 13.5 ± 8.3 mmHg; P = 0.84).

CONCLUSIONS

Serum sodium concentrations did not correlate with ICP values. These results warrant further evaluation and possible reassessment of sodium goals for ICP management in patients with TBI.