Impact of Moderate Hyperchloremia on Clinical Outcomes in Intracerebral Hemorrhage Patients Treated With Continuous Infusion Hypertonic Saline: A Pilot Study

Acute kidney injury after intracerebral hemorrhage: a mini review

Intracerebral hemorrhage (ICH) stands as a prevalent and pivotal clinical condition. The potential cooccurrence of acute kidney injury (AKI) among afflicted individuals can profoundly influence their prognosis. In recent times, there has been a growing focus among clinical practitioners on researching the relationship between ICH and AKI. AKI occurring concurrently with ICH predominantly arises from both hemodynamic and non-hemodynamic mechanisms. The latter encompasses neurohumoral regulation, inflammatory response, oxidative stress, and iatrogenic factors such as contrast agents, dehydrating agents, antibiotics, and diuretics. Moreover, advanced age, hypertension, elevated baseline creatinine levels, chronic kidney disease, and larger hematomas predispose patients to AKI. Additionally, the current utilization of biomarkers and the development of predictive models appear promising in identifying patients at risk of AKI after ICH. This article aims to underscore the potential of the aforementioned insights to inspire novel approaches to early clinical intervention.

Effect of continuous hypertonic saline infusion on clinical outcomes in patients with traumatic brain injury

Osmotic therapy has been recognized as an important treatment option for patients with traumatic brain injury (TBI). Nevertheless, the effect of hypertonic saline (HTS) remains unknown, as findings are primarily based on a large database. This study aimed to elucidate the effect of HTS on the clinical outcomes of patients with TBI admitted to the intensive care unit (ICU). We retrospectively identified patients with moderate-to-severe TBI from two public databases: Medical Information Mart for Intensive Care (MIMIC)-IV and eICU Collaborative Research Database (eICU-CRD). A marginal structural Cox model (MSCM) was used, with time-dependent variates designed to reflect exposure over time during ICU stay. Trajectory modeling based on the intracranial pressure evolution pattern allowed for the identification of subgroups. Overall, 130 (6.65%) of 1955 eligible patients underwent HTS. MSCM indicated that the HTS significantly associated with higher infection complications (e.g., urinary tract infection (HR 1.88, 95% CI 1.26-2.81, p = 0.002)) and increased ICU LOS (HR 2.02, 95% CI 1.71-2.40, p < 0.001). A protective effect of HTS on GCS was found in subgroups with medium and low intracranial pressure. Our study revealed no significant difference in mortality between patients who underwent HTS and those who did not. Increased occurrence rates of infection and electrolyte imbalance are inevitable outcomes of continuous HTS infusion. Although the study suggests slight beneficial effects, including better neurological outcomes, these results warrant further validation.

Acute kidney injury in neurocritical care

Approximately 20% of patients with acute brain injury (ABI) also experience acute kidney injury (AKI), which worsens their outcomes. The metabolic and inflammatory changes associated with AKI likely contribute to prolonged brain injury and edema. As a result, recognizing its presence is important for effectively managing ABI and its sequelae. This review discusses the occurrence and effects of AKI in critically ill adults with neurological conditions, outlines potential mechanisms connecting AKI and ABI progression, and highlights AKI management principles. Tailored approaches include optimizing blood pressure, managing intracranial pressure, adjusting medication dosages, and assessing the type of administered fluids. Preventive measures include avoiding nephrotoxic drugs, improving hemodynamic and fluid balance, and addressing coexisting AKI syndromes. ABI patients undergoing renal replacement therapy (RRT) are more susceptible to neurological complications. RRT can negatively impact cerebral blood flow, intracranial pressure, and brain tissue oxygenation, with effects tied to specific RRT methods. Continuous RRT is favored for better hemodynamic stability and lower risk of dialysis disequilibrium syndrome. Potential RRT modifications for ABI patients include adjusted dialysate and blood flow rates, osmotherapy, and alternate anticoagulation methods. Future research should explore whether these strategies enhance outcomes and if using novel AKI biomarkers can mitigate AKI-related complications in ABI patients.

Patient-Specific Risk Factors Associated With the Development of Hyperchloremia in a Neurocritical Care Intensive Care Unit

BACKGROUND

Hypertonic sodium chloride (HTS) is used in intensive care unit (ICU) settings to manage cerebral edema, intracranial hypertension, and for the treatment of severe hyponatremia. It has been associated with an increased incidence of hyperchloremia; however, there is limited literature focusing on hyperchloremic risk in neurologically injured patients. Objective: The primary objective of this study was to determine risk factors associated with development of hyperchloremia in a neurocritical care (NCC) ICU population.

METHODS

This was a retrospective case-control study performed in an adult NCC ICU and included patients receiving HTS. The primary outcome was to evaluate patient characteristics and treatments associated with hyperchloremia. Secondary outcomes included acute kidney injury and mortality.

RESULTS

Overall, 133 patients were identified; patients who were hyperchloremic were considered cases (n = 100) and patients without hyperchloremia were considered controls (n = 33). Characteristics and treatments were evaluated with univariate analysis and a logistic regression model. In the multivariate model, APACHE II Score, initial serum osmolality, total 3% saline volume, and total 23.4% saline volume were significant predictors for hyperchloremia. In addition, patients with a serum chloride greater than 113.5 mEq/L were found to have a higher risk of acute kidney injury (AKI) (adjusted OR 3.15; 95% CI 1.10-9.04).

CONCLUSIONS

This study demonstrated APACHE II Score, initial serum osmolality, and total 3% and 23.4% saline volumes were associated with developing hyperchloremia in the NCC ICU. In addition, hyperchloremia is associated with an increased risk of AKI.

Early Hyperchloremia and Outcomes After Severe Traumatic Brain Injury: Analysis of Resuscitation Outcomes Consortium Hypertonic Saline Trial

To investigate the effect of the occurrence of early hyperchloremia on death or severe disability at 180 days in patients with severe traumatic brain injury (TBI).

DESIGN

Post hoc analysis of Resuscitation Outcomes Consortium Hypertonic Saline (ROC HS)-TBI trial.

SETTING

A total of 114 North American emergency medical services agencies in the ROC.

PATIENTS

A total of 991 patients with severe TBI and Glasgow Coma Scale score of less than or equal to 8.

INTERVENTIONS

Prehospital resuscitation with single IV dose (250 cc) of 7.5% saline in 6% dextran-70, 7.5% saline (no dextran), or crystalloid.

MEASUREMENTS AND MAIN RESULTS

Patients with increased serum chloride concentrations (110 mmol/L or greater) 24 hours after randomization were identified. Hyperchloremia was graded into one or greater than or equal to 2 occurrences in the first 24 hours. Logistic regression analyses were performed to determine the effects of hyperchloremia on: 1) death or severe disability at 180 days and 2) death within 180 days after adjusting for confounders. Compared with patients without hyperchloremia, patients with greater than or equal to 2 occurrences of hyperchloremia had significantly higher odds of death or severe disability at 180 days (odds ratio [OR], 1.81; 95% CI, 1.19-2.75) and death within 180 days (OR, 1.89; 95% CI, 1.14-3.08) after adjustment for confounders. However, the total volume of fluids administered during the first 24 hours was an independent predictor of death within 180 days; therefore, after adding an interaction term between the total volume of fluids administered during the first 24 hours and greater than or equal to 2 occurrences of hyperchloremia, patients with greater than or equal to 2 occurrences of hyperchloremia had significantly higher odds of death within 180 days (OR, 2.35; 95% CI, 1.21-4.61 d) but not of composite outcome of death or severe disability at 180 days.

CONCLUSIONS

After modifying for the effect of the total volume of fluids administered during the first 24 hours, multiple occurrences of hyperchloremia in the first 24 hours were associated with higher odds of death within 180 days in patients with severe TBI.

Association between leukocyte subpopulations and hematoma expansion after spontaneous intracerebral hemorrhage: A retrospective cohort study

Aims

To verify the association between leukocyte subpopulations and hematoma expansion (HE) determined by two definitions in Chinese individuals who experienced spontaneous intracerebral hemorrhage.

Methods

We enrolled 471 patients. The 1/2ABC formula was used to gauge hematoma volume. The outcome was whether HE appeared within 72 h. We used Definition 1 (volume increase ≥6 mL or 33%) and Definition 2 (volume increase ≥12.5 mL or 33%) to define HE, respectively. Binary logistic regression analysis was used to assess the association between leukocyte subpopulations and HE. For statistically significant leukocyte subpopulations, we also performed subgroup analyses to assess differences between subgroups.

Results

Among 471 patients, 131 (27.81%) and 116 (24.63%) patients experienced HE based on Definition 1 and Definition 2, respectively. After adjusting for confounding factors, elevated monocyte count was associated with a higher risk of HE-Definition 1 [adjusted odds ratio (aOR) 2.45, 95% confidence interval (CI) 1.02–5.88, P = 0.0450] and HE-Definition 2 (aOR 2.54, 95% CI 1.04–6.20, P = 0.0399). Additionally, we compared the results before and after adjusting for coagulation parameters. Monocyte count was significantly correlated with HE only after adjusting for coagulation parameters. Increased neutrophil count was associated with a lower risk of HE-Definition 1 (aOR 0.91, 95% CI 0.84–1.00, P = 0.0463). No correlations were observed between lymphocyte and leukocyte counts and HE (P > 0.05), and no subgroup interactions were observed (interaction P > 0.05).

Conclusion

A higher monocyte count is associated with a higher HE risk regardless of the two definitions, after excluding the influence of the coagulation parameters, which facilitates risk stratification. Moreover, an increased neutrophil count is associated with a decreased risk of HE in the context of HE-Definition 1, which reflects the importance of standardizing the definition of HE.

Increase in chloride from baseline is independently associated with mortality in intracerebral hemorrhage patients admitted to intensive care unit: A retrospective study

Background

Hyperchloremia is associated with increased mortality in critically ill patients. The objective of this study was to investigate the association between increased chloride levels and mortality outcomes in intracerebral hemorrhage (ICH) patients admitted to the intensive care unit (ICU).

Methods

We performed a retrospective study of all patients diagnosed with ICH and included in the Medical Information Mart for Intensive Care (MIMIC-Ⅲ) from 2001 to 2012. Inclusion criteria were the first diagnosis of ICH, ICU length of stay (LOS) over 72 h, and not receiving hypertonic saline treatment. Serum chloride perturbation within 72 h of admission was evaluated as a predictor of outcomes. The increase in chloride from baseline was dichotomized based on an increase in chloride in 72 h (≤5 mmol/L or >5 mmol/L). The primary outcome was 90-day mortality.

Results

A total of 376 patients (54.5% male, median age 70 years, interquartile range:58-79 years) were included. The overall 90-day mortality was 32.2% (n=121), in-hospital mortality was 25.8% (n=97), and Day 2 acute kidney injury (AKI) occurred in 29.0% (n=109) of patients. The prevalence of hyperchloremia on admission, during the first 72 h, and an increase in chloride (>5 mmol/L) were 8.8%, 39.4%, and 42.8%, respectively. After adjusting for confounders, the hazard ratio of increase in chloride (>5 mmol/L) was 1.66 (95% confidence interval:1.05-2.64, P=0.031). An increase in chloride (>5 mmol/L) was associated with a higher odds ratio for 90-day mortality in both the AKI and non-AKI groups.

Conclusions

An increase in chloride from baseline is common in adult patients with ICH admitted to ICU. The increase is significantly associated with elevated mortality. These results support the significance of diligently monitoring chloride levels in these patients.

Early Hyperchloremia is Independently Associated with Death or Disability in Patients with Intracerebral Hemorrhage

BACKGROUND

On the basis of increased mortality associated with hyperchloremia among critically ill patients, we investigated the effect of occurrence of early hyperchloremia on death or disability at 90 days in patients with intracerebral hemorrhage (ICH).

METHODS

We analyzed the data from Antihypertensive Treatment of Cerebral Hemorrhage 2 trial, which recruited patients with spontaneous ICH within 4.5 h of symptom onset. Patients with increased serum chloride levels (110 mmol/L or greater) at either baseline or 24, 48, or 72 h after randomization were identified. We further graded hyperchloremia into one occurrence or two or more occurrences within the first 72 h. Two logistic regression analyses were performed to determine the effects of hyperchloremia on (1) death within 90 days and (2) death or disability at 90 days after adjustment for potential confounders.

RESULTS

Among the total of 1,000 patients analyzed, hyperchloremia within 72 h was seen in 114 patients with one occurrence and in 154 patients with two or more occurrences. Patients with one occurrence of hyperchloremia (odds ratio [OR] 2.5, 95% confidence interval [CI] 1.1-5.5) and those with two or more occurrences (OR 2.6, 95% CI 1.3-5.0) had significantly higher odds of death within 90 days after adjustment for age, race and ethnicity, National Institutes of Health Stroke Scale score strata, hematoma volume, presence or absence of intraventricular hemorrhage, cigarette smoking, previous stroke, and maximum hourly dose of nicardipine. Patients with two or more occurrences of hyperchloremia (OR 3.4, 95% CI 2.1-5.6) had significantly higher odds of death or disability at 90 days compared with patients without hyperchloremia after adjustment for the abovementioned potential confounders.

CONCLUSIONS

The independent association between hyperchloremia and death or disability at 90 days suggests that avoidance of hyperchloremia may reduce the observed death or disability in patients with ICH.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov: NCT01176565.

A teaspoon of sugar and a pinch of salt: Reviewing hyperosmolar therapy

ABSTRACT

The traditional hyperosmolar agents used to treat patients with elevated intracranial pressure are mannitol and hypertonic sodium chloride solution. This article focuses on some of the pros and cons of these treatments for managing cerebral edema.

Hypertonic lactate for the treatment of intracranial hypertension in patients with acute brain injury

Hypertonic lactate (HL) is emerging as alternative treatment of intracranial hypertension following acute brain injury (ABI), but comparative studies are limited. Here, we examined the effectiveness of HL on main cerebral and systemic physiologic variables, and further compared it to that of standard hypertonic saline (HS). Retrospective cohort analysis of ABI subjects who received sequential osmotherapy with 7.5% HS followed by HL-given at equi-osmolar (2400 mOsmol/L) and isovolumic (1.5 mL/kg) bolus doses-to reduce sustained elevations of ICP (> 20 mmHg). The effect of HL on brain (intracranial pressure [ICP], brain tissue PO₂ [PbtO₂], cerebral microdialysis [CMD] glucose and lactate/pyruvate ratio [LPR]) and blood (chloride, pH) variables was examined at different time-points (30, 60, 90, 120 min vs. baseline), and compared to that of HS. A total of 34 treatments among 17 consecutive subjects (13 traumatic brain injury [TBI], 4 non-TBI) were studied. Both agents significantly reduced ICP (p < 0.001, at all time-points tested): when comparing treatment effectiveness, absolute ICP decrease in mmHg and the duration of treatment effect (median time with ICP < 20 mmHg following osmotherapy 183 [108-257] vs. 150 [111-419] min) did not differ significantly between HL and HS (all p > 0.2). None of the treatment had statistically significant effects on PbtO₂ and CMD biomarkers. Treatment with HL did not cause hyperchloremia and resulted in a more favourable systemic chloride balance than HS (Δ blood chloride - 1 ± 2.5 vs. + 4 ± 3 mmol/L; p < 0.001). This is the first clinical study showing that HL has comparative effectiveness than HS for the treatment of intracranial hypertension, while at the same time avoiding hyperchloremic acidosis. Both agents had no significant effect on cerebral oxygenation and metabolism.

Effect of half-molar sodium lactate infusion on biochemical parameters in critically ill patients

OBJECTIVE

To evaluate the impact of the infusion of sodium lactate 500ml upon different biochemical variables and intracranial pressure in patients admitted to the intensive care unit.

DESIGN

A prospective experimental single cohort study was carried out.

SCOPE

Polyvalent intensive care unit of a university hospital.

PATIENTS

Critical patients with shock and intracranial hypertension.

PROCEDURE

A 500ml sodium lactate bolus was infused in 15min. Plasma levels of sodium, potassium, magnesium, calcium, chloride, lactate, bicarbonate, PaCO₂, pH, phosphate and albumin were recorded at 3 timepoints: T0 pre-infusion; T1 at 30min, and T2 at 60min post-infusion. Mean arterial pressure and intracranial pressure were measured at T0 and T2.

RESULTS

Forty-one patients received sodium lactate: 19 as an osmotically active agent and 22 as a volume expander. Metabolic alkalosis was observed: T0 vs. T1 (p=0.007); T1 vs. T2 (p=0.003). Sodium increased at the 3 timepoints (T0 vs. T1, p<0.0001; T1 vs. T2, p=0.0001). In addition, sodium lactate decreased intracranial pressure (T0: 24.83±5.4 vs. T2: 15.06±5.8; p<0.001). Likewise, plasma lactate showed a biphasic effect, with a rapid decrease at T2 (p<0.0001), including in those with previous hyperlactatemia (p=0.002).

CONCLUSIONS

The infusion of sodium lactate is associated to metabolic alkalosis, hypernatremia, reduced chloremia, and a biphasic change in plasma lactate levels. Moreover, a decrease in intracranial pressure was observed in patients with acute brain injury.

Intravenous Fluid Selection for Unruptured Intracranial Aneurysm Clipping : Balanced Crystalloid versus Normal Saline

OBJECTIVE

While balanced crystalloid (BC) could be a relevant fluid regimen with buffer system compared with normal saline (NS), there have been no studies on the optimal fluid for surgery of an unruptured intracranial aneurysm (UIA). This study aimed to compare the effects of fluid regimens between NS and BC on the metabolic and clinical outcomes of patients who underwent surgery for UIA.

METHODS

This study was designed as a propensity score matched retrospective comparative study and included adult patients who underwent UIA clipping. Patient groups were categorized as NS and BC groups based on the types of pre-operative fluid and the amount of fluid administered during surgery. The primary outcomes were defined as electrolyte imbalance and acidosis immediately after surgery. The secondary outcomes were the length of stay in the intensive care unit (ICU) and duration from the end of the operation to extubation.

RESULTS

A total of 586 patients were enrolled in this study, with each of 293 patients assigned to the NS and BC groups, respectively. Immediately after surgery, serum chloride levels were significantly higher in the NS group. Compared to the NS group, the BC group had lower incidence rates of acidemia (6.5% vs. 11.6%, p=0.043) and metabolic acidosis (0.7% vs. 4.4%, p=0.007). As compared to NS group, BC group had significantly shorter duration from the end of the operation to extubation (250±824 vs. 122±372 minutes, p=0.016) and length of stay in ICU (1.37±1.11 vs. 1.12±0.61 days, p=0.001). Throughout multivariable analysis, use of BC was found to be significant factor for favorable post-operative results.

CONCLUSION

This study showed that the patients who received BC during UIA clipping had lower incidence of metabolic acidosis, earlier extubation and shorter ICU stay compared to those who received NS. Therefore, using BC as a peri-operative fluid can be recommended for patients who undergo surgery for UIA.

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.

An Audit and Comparison of pH, Measured Concentration, and Particulate Matter in Mannitol and Hypertonic Saline Solutions

Background: The preferred hyperosmolar therapy remains controversial. Differences in physical properties such as pH and osmolality may be important considerations in hyperosmolar agent selection. We aimed to characterize important physical properties of commercially available hyperosmolar solutions.

Methods: We measured pH and concentration in 37 commonly-used hyperosmolar solutions, including 20 and 25% mannitol and 3, 5, 14.6, and 23.4% hypertonic saline. pH was determined digitally and with litmus paper. Concentration was determined by freezing point and vapor pressure osmometry. Salinity/specific gravity was measured with portable refractometry. Particulate matter was analyzed with filtration and light microscopy and with dynamic light scattering nephelometry.

Results: pH of all solutions was below physiological range (measured range 4.13–6.80); there was no correlation between pH and solution concentration (R² = 0.005, p = 0.60). Mannitol (mean 5.65, sd 0.94) was less acidic than hypertonic saline (5.16, 0.60). 14/59 (24%) pH measurements and 85/111 concentration measurements were outside manufacturer standards. All 36/36 mannitol concentration measurements were outside standards vs. 48/72 (67%) hypertonic saline (p < 0.0001). All solutions examined on light microscopy contained crystalline and/or non-crystalline particulate matter up to several hundred microns in diameter. From nephelometry, particulate matter was detected in 20/22 (91%) solutions.

Conclusion: We present a novel characterization of mannitol and hypertonic saline. Further research should be undertaken, including research examining development of acidosis following hyperosmolar therapy, the relevance of our findings for dose-response, and the clinical relevance of particulate matter in solution.

Glycerol Infusion Versus Mannitol for Cerebral Edema: A Systematic Review and Meta-analysis

PURPOSE

For the treatment of cerebral edema, the use of glycerol, an osmotic agent, as well as mannitol, is popular in Asia. However, the relative therapeutic benefit of glycerol remains unknown. The goal of this study was to investigate the comparative efficacy and safety of glycerol infusion versus mannitol infusion for cerebral edema.

METHODS

A systematic search was performed in PubMed, Cochrane Central Register of Controlled Trials, Web of Science, EMBASE, and Scopus for all eligible articles published before July 2020, with no restrictions on language. Two reviewers independently screened the articles, extracted data, and carefully assessed the quality of the evidence.

FINDINGS

Eight studies (6 clinical, 2 animal) were ultimately included in the qualitative analysis, and five were included in the quantitative analysis. Pooled analyses revealed nonsignificant differences in the successful control of cerebral edema (relative risk [RR], 0.97; 95% CI, 0.81-1.15). The combination therapy with glycerol led to a favorable trend in neurologic improvements. Regarding safety, glycerol was associated with a significantly lower risk of acute kidney injury (RR, 0.27; 95% CI, 0.11-0.69) and electrolyte disturbances (RR, 0.20; 95% CI, 0.06-0.64), as well as a lower possibility of rebound effects. No hemolysis was observed at the final follow-up.

IMPLICATIONS

Although the data are limited, compared with mannitol, glycerol shows a similar level of effectiveness, a more favorable safety profile, and promising neurologic improvement in individuals with cerebral edema. Additional research is needed to confirm these findings.

PROSPERO

CRD42020187702.

An update on the pharmacological management and prevention of cerebral edema: current therapeutic strategies

Introduction: Cerebral edema is a common complication of multiple neurological diseases and is a strong predictor of outcome, especially in traumatic brain injury and large hemispheric infarction.Areas Covered: Traditional and current treatments of cerebral edema include treatment with osmotherapy or decompressive craniectomy at the time of clinical deterioration. The authors discuss preclinical and clinical models of a variety of neurological disease states that have identified receptors, ion transporters, and channels involved in the development of cerebral edema as well as modulation of these receptors with promising agents.Expert opinion: Further study is needed on the safety and efficacy of the agents discussed. IV glibenclamide has shown promise in preclinical and clinical trials of cerebral edema in large hemispheric infarct and traumatic brain injury. Consideration of underlying pathophysiology and pharmacodynamics is vital, as the synergistic use of agents has the potential to drastically mitigate cerebral edema and secondary brain injury thusly transforming our treatment paradigms.

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.

Association of Hyperchloremia and Acute Kidney Injury in Patients With Traumatic Brain Injury

Introduction:

Hypertonic saline is often used to treat patients with traumatic brain injury. It carries the undesired side effect of hyperchloremia, which has been linked to acute kidney injury (AKI). We sought to evaluate the relationship of hyperchloremia and AKI in this population and whether the absolute exposure to hyperchloremia, including maximal hyperchloremia and duration of hyperchloremia were associated with AKI.

Methods:

A retrospective study of severe traumatic brain injury patients who received hypertonic saline at a single academic institution. Demographics, head abbreviated injury scale, development of hyperchloremia (Cl ≥ 115), duration of hyperchloremia, highest chloride level, duration of hypertonic saline use, admission GFR, and administration of nephrotoxic medications were abstracted. The outcome of interest was the association between renal function and hyperchloremia.

Results:

A total of 123 patients were included in the study. Multivariable logistic regression analysis demonstrated that only duration of hyperchloremia ( p = 0.014) and GFR on admission ( p = 0.004) were independently associated with development of AKI. The number of days of hypertonic saline infusion ( p = 0.79) without the persistence of hyperchloremia and highest serum chloride levels ( p = 0.23) were not predictive of AKI development.

Discussion:

In patients with traumatic brain injury, admission GFR and prolonged hyperchloremia rather than the highest chloride level or the duration of hypertonic saline infusion were associated with the development of AKI.

Peak Serum Chloride and Hyperchloremia in Patients Undergoing Cardiac Surgery Is Not Explained by Chloride-Rich Intravenous Fluid Alone: A Post-Hoc Analysis of the LICRA Trial

OBJECTIVES

With the exception of 0.9% saline, little is known about factors that may contribute to increased serum chloride concentration (S_Cl^-) in patients undergoing cardiac surgery. For the present study, the authors sought to characterize the association between administered chloride load from intravenous fluid and other perioperative variables, with peak perioperative S_Cl^-.

DESIGN

Secondary analysis of data from a previously published controlled clinical trial in which patients were assigned to a chloride-rich or chloride-limited perioperative fluid strategy (NCT02020538).

SETTING

Academic medical center.

PARTICIPANTS

The study comprised 1,056 adult patients with normal preoperative S_Cl^- undergoing cardiac surgery.

INTERVENTIONS

None MEASUREMENTS AND MAIN RESULTS: Peak perioperative S_Cl^- and hyperchloremia, defined as peak S_Cl^- >110 mmol/L, were selected as co-primary endpoints. Regression modeling identified factors independently associated with these endpoints. Mean (standard deviation) peak perioperative S_Cl^- was 114 (5) mmol/L, and hyperchloremia occurred in 824 (78.0%) of the cohort. In addition to administered volume of 0.9% saline, multivariate linear and logistic regression modeling consistently associated preoperative S_Cl^- (regression coefficient 0.5; 95% confidence interval [CI] 0.4-0.6 mmol/L; odds ratio 1.60; 95% CI 1.41-1.82 per 1 mmol/L increase) and cardiopulmonary bypass duration (regression coefficient 0.1; 95% CI 0.1-0.2 mmol/L; odds ratio 1.12; 95% CI 1.06-1.19 per 10 minutes) with both co-primary outcomes. Multivariate modeling only explained approximately 50% of variability in peak S_Cl^-.

CONCLUSIONS

The present study's data identified an association for both 0.9% saline administration and other nonfluid variables with peak perioperative S_Cl^- and hyperchloremia. Stand-alone strategies to limit administration of chloride-rich intravenous fluid may have limited ability to prevent hyperchloremia in this setting.

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 Association Between Hyperchloremia and Acute Kidney Injury in Patients With Acute Ischemic Stroke

Background and Purpose

While an association between hyperchloremia and worse outcomes, such as acute kidney injury and increased mortality, has been demonstrated in hemorrhagic stroke, it is unclear whether the same relationship exists after acute ischemic stroke. This study aims to determine the relationship between moderate hyperchloremia (serum chloride ≥115 mmol/L) and acute kidney injury in patients with ischemic stroke.

Methods

This is a multicenter, retrospective, propensity-matched cohort study of adults admitted for acute ischemic stroke. The primary objective was to determine the relationship between moderate hyperchloremia and acute kidney injury, as defined by the Acute Kidney Injury Network criteria. Secondary objectives included mortality and hospital length of stay.

Results

A total of 407 patients were included in the unmatched cohort (332 nonhyperchloremia and 75 hyperchloremia) and 114 patients (57 in each group) were matched based upon propensity scores. In the matched cohort, hyperchloremia was associated with an increased risk of acute kidney injury (relative risk 1.91 [95% confidence interval 1.01-3.59]) and a longer hospital length of stay (16 vs 12 days; P = .03). Mortality was higher in the hyperchloremia group (19.3% vs 10.5%, P = .19), but this did not reach statistical significance.

Conclusions

In this study, hyperchloremia after ischemic stroke was associated with increased rates of acute kidney injury and longer hospital length of stay. Further research is needed to determine which interventions may increase chloride levels in patients with acute ischemic stroke and the association between hyperchloremia and clinical outcomes.

Fluids and hyperosmolar agents in neurocritical care: an update

PURPOSE OF REVIEW

To discuss recent updates in fluid management and use of hyperosmolar therapy in neurocritical care.

RECENT FINDINGS

Maintaining euvolemia with crystalloids seems to be the recommended fluid resuscitation for neurocritical care patients. Buffered crystalloids have been shown to reduce hyperchloremia in patients with subarachnoid hemorrhage without causing hyponatremia or hypo-osmolality. In addition, in patients with traumatic brain injury, buffered solutions reduce the incidence of hyperchloremic acidosis but are not associated with intracranial pressure (ICP) alteration. Both mannitol and hypertonic saline are established as effective hyperosmolar agents to control ICP. Both agents have been shown to control ICP, but their effects on neurologic outcomes are unclear. A recent surge in preference for using hypertonic saline as a hyperosmolar agent is based on few studies without strong evidence.

SUMMARY

Fluid resuscitation with crystalloids seems to be reasonable in this setting although no recommendations can be made regarding type of crystalloids. Based on current evidence, elevated ICP can be effectively reduced by either hypertonic saline or mannitol.

Hyperchloremia, not Concomitant Hypernatremia, Independently Predicts Early Mortality in Critically Ill Moderate-Severe Traumatic Brain Injury Patients

BACKGROUND

Hypernatremia has been associated with mortality in neurocritically ill patients, with and without traumatic brain injury (TBI). These studies, however, lack concomitant adjustment for hyperchloremia as a physiologically co-occurring finding despite the associations with hyperchloremia and worse outcomes after trauma, sepsis, and intracerebral hemorrhage. The objective of our study was to examine the association of concomitant hypernatremia and hyperchloremia with in-hospital mortality in moderate-severe TBI (msTBI) patients.

METHODS

We retrospectively analyzed prospectively collected data from the OPTIMISM-study and included all msTBI patients consecutively enrolled between 11/2009 and 1/2017. Time-weighted average (TWA) sodium and chloride values were calculated for all patients to examine the unadjusted mortality rates associated with the burden of hypernatremia and hyperchloremia over the entire duration of the intensive care unit stay. Multivariable logistic regression modeling predicting in-hospital mortality adjusted for validated confounders of msTBI mortality was applied to evaluate the concomitant effects of hypernatremia and hyperchloremia. Internal bootstrap validation was performed.

RESULTS

Of the 458 patients included for analysis, 202 (44%) died during the index hospitalization. Fifty-five patients (12%) were excluded due to missing data. Unadjusted mortality rates were nearly linearly increasing for both TWA sodium and TWA chloride, and were highest for patients with a TWA sodium > 160 mmol/L (100% mortality) and TWA chloride > 125 mmol/L (94% mortality). When evaluated separately in the multivariable analysis, TWA sodium (per 10 mmol/L change: adjusted OR 4.0 [95% CI 2.1-7.5]) and TWA chloride (per 10 mmol/L change: adjusted OR 3.9 [95% CI 2.2-7.1]) independently predicted in-hospital mortality. When evaluated in combination, TWA chloride remained independently associated with in-hospital mortality (per 10 mmol/L change: adjusted OR 2.9 [95% CI 1.1-7.8]), while this association was no longer observed with TWA sodium values (per 10 mmol/L change: adjusted OR 1.5 [95% CI 0.51-4.4]).

CONCLUSIONS

When concomitantly adjusting for the burden of hyperchloremia and hypernatremia, only hyperchloremia was independently associated with in-hospital mortality in our msTBI cohort. Pending validation, our findings may provide the rationale for future studies with targeted interventions to reduce hyperchloremia and improve outcomes in msTBI patients.

Effect of half-molar sodium lactate infusion on biochemical parameters in critically ill patients

OBJECTIVE

To evaluate the impact of the infusion of sodium lactate 500ml upon different biochemical variables and intracranial pressure in patients admitted to the intensive care unit.

DESIGN

A prospective experimental single cohort study was carried out.

SCOPE

Polyvalent intensive care unit of a university hospital.

PATIENTS

Critical patients with shock and intracranial hypertension.

PROCEDURE

A 500ml sodium lactate bolus was infused in 15min. Plasma levels of sodium, potassium, magnesium, calcium, chloride, lactate, bicarbonate, PaCO₂, pH, phosphate and albumin were recorded at 3timepoints: T0 pre-infusion; T1 at 30minutes, and T2 at 60minutes post-infusion. Mean arterial pressure and intracranial pressure were measured at T0 and T2.

RESULTS

Forty-one patients received sodium lactate: 19 as an osmotically active agent and 22 as a volume expander. Metabolic alkalosis was observed: T0 vs. T1 (P=0.007); T1 vs. T2 (P=0.003). Sodium increased at the 3time points (T0 vs. T1, P<0.0001; T1 vs. T2, P=0.0001). In addition, sodium lactate decreased intracranial pressure (T0: 24.83±5.4 vs. T2: 15.06±5.8; P<0.001). Likewise, plasma lactate showed a biphasic effect, with a rapid decrease at T2 (P<0.0001), including in those with previous hyperlactatemia (P=0.002).

CONCLUSIONS

The infusion of sodium lactate is associated to metabolic alkalosis, hypernatremia, reduced chloremia, and a biphasic change in plasma lactate levels. Moreover, a decrease in intracranial pressure was observed in patients with acute brain injury.

Assessment of Acute Kidney Injury in Neurologically Injured Patients Receiving Hypertonic Sodium Chloride: Does Chloride Load Matter?

Background: Increasing evidence suggests that large-volume infusions of 0.9% sodium chloride (NaCl) for resuscitation are associated with hyperchloremic metabolic acidosis, renal vasoconstriction, and increased risk of acute kidney injury (AKI). Patients with neurological injury may require hypertonic NaCl for therapeutic hypernatremia, treatment of cerebral salt wasting, hyponatremia, or elevated intracranial pressure. Consequently, this increased exposure to chloride may result in an increased risk for development of AKI. Objective: The primary aim of this study was to describe the risk for development of AKI in neurologically injured patients receiving large volumes of intravenous hypertonic NaCl. Methods: This single-center, retrospective study looked at neurologically injured patients who received hypertonic NaCl and sodium acetate. Data were collected to assess renal function, hyperchloremia, and acidemia. Receiver operating characteristic (ROC) curve analysis was used to determine the predictive association between the amount of daily and overall chloride exposure and development of AKI. Results: A total of 301 patients were screened, and of those, 142 were included. Of the 142 patients included, 13% developed AKI, and 38% developed hyperchloremia. Additionally, 32% of patients were switched from NaCl to sodium acetate after an average of 3.4 ± 1.5 days of NaCl therapy. The ROC curve demonstrated that if patients received greater than 2055 mEq of chloride over 7 days, they were more likely to develop AKI (sensitivity 72%, specificity 70%; P = 0.002; area under the curve = 0.7). Conclusion and Relevance: Neurologically injured patients receiving hypertonic sodium therapy with a high chloride load are at risk of developing hyperchloremia and AKI.

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.

Acute Management of Hypertension Following Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH) is responsible for approximately 15% of strokes annually in the United States, with nearly 1 in 3 of these patients dying without ever leaving the hospital. Because this disproportionate mortality risk has been stagnant for nearly 3 decades, a main area of research has been focused on the optimal strategies to reduce mortality and improve functional outcomes. The acute hypertensive response following ICH has been shown to facilitate ICH expansion and is a strong predictor of mortality. Rapidly reducing blood pressure was once thought to induce cerebral ischemia, though has been found to be safe in certain patient populations. Clinicians must work quickly to determine whether specific patient populations may benefit from acute lowering of systolic blood pressure (SBP) following ICH. This review provides nurses with a summary of the available literature on blood pressure control following ICH. It focuses on intravenous and oral antihypertensive medications available in the United States that may be utilized to acutely lower SBP, as well as medications outside of the antihypertensive class used during the acute setting that may reduce SBP.

Aggressive Resuscitation Is Associated with the Development of Acute Kidney Injury in Acute Pancreatitis

INTRODUCTION

The association between early resuscitation volume and clinical outcomes remains controversial in acute pancreatitis. In the present study, we aimed to identify the association between resuscitation volume and the development of acute kidney injury (AKI) and other clinical outcome metrics.

METHODS

Patients admitted to our center with moderately severe acute pancreatitis (MSAP) and severe acute pancreatitis (SAP) from January 2009 to December 2013 were reviewed retrospectively. Patients were stratified into two groups on the basis of the volume of fluid infused during the first 24 h. The primary clinical endpoint was incidence of AKI. Moreover, AKI lasting time, utilization of continuous renal replacement therapy and lasting time, creatinine increase, and other clinical metrics were also compared. The potential risk factors of new-onset AKI were also analyzed.

RESULTS

A total of 179 patients were included, and aggressive fluid resuscitation (≥ 4 l) was associated with increased incidence of AKI compared with nonaggressive group (53.12% vs. 25.64%, p = 0.008), longer AKI lasting time (p = 0.038), and increased creatinine increase (p < 0.001) during hospitalization. Moreover, utilization of continuous renal replacement therapy was more frequent in aggressive group (40.63% vs. 24.36%, p = 0.108), and the lasting time of continuous renal replacement therapy was also longer (p = 0.181), though both not statistically different. Moreover, in multivariate analysis, aggressive resuscitation [OR 4.36 (1.52-13.62); p = 0.001] and chloride exposure [OR 2.53 (1.26-5.21); p = 0.012] in the first 24 h were risk factors of new-onset AKI.

CONCLUSION

In patients with MSAP and SAP, aggressive fluid resuscitation was associated with increased incidence and longer duration of AKI. Moreover, aggressive resuscitation and chloride exposure in the first 24 h were risk factors of new-onset AKI.

Increase in serum chloride and chloride exposure are associated with acute kidney injury in moderately severe and severe acute pancreatitis patients

OBJECTIVE

We aimed to evaluate whether early (first 48 h) hyperchloremia and/or the change of serum chloride concentration are associated with acute kidney injury (AKI) in patients with moderately severe and severe acute pancreatitis (MSAP and SAP).

METHODS

We retrospectively collected the data of patients with a primary diagnosis of MSAP or SAP from a tertiary center between January 2014 and June 2017. Consecutive chloride levels within the first 48 h after admission were retrieved for further calculation. Logistic regression analysis and receiving operating characteristic (ROC) curve were used to assess the relationship between hyperchloremia and AKI.

RESULTS

145 patients were enrolled for analysis, of whom 33.5% (47/145) developed hyperchloremia during the observation period. The incidence of AKI was significantly higher in the hyperchloremia group (40.4% vs 7.1%; p < 0.001). On multivariate analysis, the increase in serum chloride (Δ[Cl-]) was independently associated with AKI [OR = 1.32 (1.00-1.74)], as was chloride exposure [OR = 1.01 (1.00-1.02)], and these associations were found to be stronger in patients identified as predicted SAP (PSAP). Moreover, even in patients without hyperchloremia, increase in serum chloride (Δ[Cl-]) was still associated with AKI [OR = 1.65 (1.18-2.32)]. Area under the curve of the ROC curve (AUCROC) analysis found that Δ[Cl-] is a good predictor of AKI with an optimal cutoff point at 3.5 mmol/L, showing an AUCROC of 0.81.

CONCLUSION

Hyperchloremia is common in patients with AP and Δ[Cl^-] and chloride exposure during the first 48 h were independent risk factors for AKI in MSAP and SAP patients.

Hyperchloremia and postoperative acute kidney injury: a retrospective analysis of data from the surgical intensive care unit

Background

Whether perioperative hyperchloremia can induce postoperative acute kidney injury (AKI) is controversial. We investigated the association between perioperative hyperchloremia and postoperative AKI in patients admitted to the intensive care unit (ICU) after surgery.

Methods

We performed a retrospective observational study of patients admitted to the surgical ICU at a single tertiary care hospital between January 2011 and June 2016. Our primary objective was to determine whether hyperchloremia or an increase in serum chloride levels was associated with postoperative AKI. Perioperative hyperchloremia was defined as serum chloride levels ≥ 110 mmol·L^− 1 during postoperative days (PODs) 0–3. The increase in serum chloride levels was defined as the difference between preoperative and maximum postoperative serum chloride levels during the first 3 days after surgery.

Results

Of the 7991 patients included in the final analysis, 1876 (23.5%) developed hyperchloremia during PODs 0–3, and 1187 (14.9%) developed postoperative AKI. Exposure to hyperchloremia during the first 3 days after surgery was not associated with postoperative AKI (odds ratio, 1.09; 95% confidence interval, 0.80–1.49; P = 0.571). However, among patients with preoperative chronic kidney disease stage ≥ 3 (estimated glomerular filtration rate < 60 mL·min^− 1·1.73·m^− 2), the incidence of postoperative AKI was higher in patients with an increase > 6 mmol·L^− 1 in serum chloride levels than in patients with an increase ≤ 1 mmol·L^− 1 (odds ratio, 1.42; 95% confidence interval, 1.09–1.84; P = 0.009). In addition, the incidence of postoperative AKI stage ≥ 2 was not associated with exposure to hyperchloremia or with the increase in serum chloride levels during PODs 0–3, regardless of preoperative kidney function.

Conclusions

Exposure to perioperative hyperchloremia is not associated with postoperative AKI in surgical ICU patients. However, in patients with moderate-to-severe chronic kidney disease (stage ≥ 3), a substantial perioperative increase in serum chloride levels may reflect a higher risk of AKI.

Electronic supplementary material

The online version of this article (10.1186/s13054-018-2216-5) contains supplementary material, which is available to authorized users.

A dose-response relationship study of hypertonic saline on brain relaxation during supratentorial brain tumour craniotomy

Background: A prospective, randomized, double-blind study was designed to assess differences in brain relaxation between 2 doses of 3% HS during elective supratentorial brain tumour surgery.Methods: 60 patients undergoing supratentorial craniotomy for tumour resection were enrolled to receive either 3 mL/kg (group L) or 5 mL/kg (group H) of 3% HS administered at skin incision. Brain relaxation was assessed after dura opening on a scale ranging 1-4 (1 = perfectly relaxed, 2 = satisfactorily relaxed, 3 = firm brain, 4 = bulging brain). Hemodynamic variables and laboratory values (blood gases, osmolarity, haematocrit, and lactate) were collected before HS infusion and 30, 120 and 360 min after it. Presence of midline shift, postoperative complications, PCU and hospital stay, and mortality after 30 days were also recorded.Results: There was no difference in brain relaxation, with 2.0 (1.0-3.0) and 2.0 (1.0-2.3) (P = 0.535) for patients in groups L and H, respectively. If adjusted for the presence of midline shift, 50% of patients had adequate brain relaxation scores (grades 1 and 2) in group L and 61% in group H (OR 0.64, CI = 0.16-2.49, P = 0.515). No significant differences in perioperative outcome, mortality and length of PCU and hospital stay were observed.Conclusion: 3 mL/kg of 3% HS result in similar brain relaxation scores as 5 mL/kg in patients undergoing craniotomy for supratentorial brain tumour. This study reveals that both high and low doses of 3% HS may be less effective on intraoperative brain relaxation in patients with midline shift.

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.

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.