Hypertonic saline reduces cumulative and daily intracranial pressure burdens after severe traumatic brain injury

Comparison of mannitol and hypertonic saline solution for the treatment of suspected brain herniation during prehospital management of traumatic brain injury patients

BACKGROUND AND IMPORTANCE

Occurrence of mydriasis during the prehospital management of traumatic brain injury (TBI) may suggest severe intracranial hypertension (ICH) subsequent to brain herniation. The initiation of hyperosmolar therapy to reduce ICH and brain herniation is recommended. Whether mannitol or hypertonic saline solution (HSS) should be preferred is unknown.

OBJECTIVES

The objective of this study is to assess whether HSS, compared with mannitol, is associated with improved survival in adult trauma patients with TBI and mydriasis.

DESIGN/SETTING AND PARTICIPANTS

A retrospective observational cohort study using the French Traumabase national registry to compare the ICU mortality of patients receiving either HSS or mannitol. Patients aged 16 years or older with moderate to severe TBI who presented with mydriasis during prehospital management were included.

OUTCOME MEASURES AND ANALYSIS

We performed propensity score matching on a priori selected variables [i.e. age, sex and initial Coma Glasgow Scale (GCS)] with a ratio of 1 : 3 to ensure comparability between the two groups. The primary outcome was ICU mortality. The secondary outcomes were regression of pupillary abnormality during prehospital management, pulsatility index and diastolic velocity on transcranial Doppler within 24 h after TBI, early ICU mortality (within 48 h), ICU and hospital length of stay.

RESULTS

Of 31 579 patients recorded in the registry between 2011 and 2021, 1417 presented with prehospital mydriasis and were included: 1172 (82.7%) received mannitol and 245 (17.3%) received HSS. After propensity score matching, 720 in the mannitol group matched 240 patients in the HSS group. Median age was 41 years [interquartile ranges (IQR) 26-60], 1058 were men (73%) and median GCS was 4 (IQR 3-6). No significant difference was observed in terms of characteristics and prehospital management between the two groups. ICU mortality was lower in the HSS group (45%) than in the mannitol group (54%) after matching [odds ratio (OR) 0.68 (0.5-0.9), P = 0.014]. No differences were identified between the groups in terms of secondary outcomes.

CONCLUSION

In this propensity-matched observational study, the prehospital osmotherapy with HSS in TBI patients with prehospital mydriasis was associated with a lower ICU mortality compared to osmotherapy with mannitol.

Hypertonic Saline Versus Other Intracranial-Pressure-Lowering Agents for Patients with Acute Traumatic Brain Injury: A Systematic Review and Meta-analysis

Acute traumatic brain injury (TBI) is a major cause of mortality and disability worldwide. Intracranial pressure (ICP)-lowering is a critical management priority in patients with moderate to severe acute TBI. We aimed to evaluate the clinical efficacy and safety of hypertonic saline (HTS) versus other ICP-lowering agents in patients with TBI. We conducted a systematic search from 2000 onward for randomized controlled trials (RCTs) comparing HTS vs. other ICP-lowering agents in patients with TBI of all ages. The primary outcome was the Glasgow Outcome Scale (GOS) score at 6 months (PROSPERO CRD42022324370). Ten RCTs (760 patients) were included. Six RCTs were included in the quantitative analysis. There was no evidence of an effect of HTS on the GOS score (favorable vs. unfavorable) compared with other agents (risk ratio [RR] 0.82, 95% confidence interval [CI] 0.48-1.40; n = 406; 2 RCTs). There was no evidence of an effect of HTS on all-cause mortality (RR 0.96, 95% CI 0.60-1.55; n = 486; 5 RCTs) or total length of stay (RR 2.36, 95% CI - 0.53 to 5.25; n = 89; 3 RCTs). HTS was associated with adverse hypernatremia compared with other agents (RR 2.13, 95% CI 1.09-4.17; n = 386; 2 RCTs). The point estimate favored a reduction in uncontrolled ICP with HTS, but this was not statistically significant (RR 0.52, 95% CI 0.26-1.04; n = 423; 3 RCTs). Most included RCTs were at unclear or high risk of bias because of lack of blinding, incomplete outcome data, and selective reporting. We found no evidence of an effect of HTS on clinically important outcomes and that HTS is associated with adverse hypernatremia. The included evidence was of low to very low certainty, but ongoing RCTs may help to the reduce this uncertainty. In addition, heterogeneity in GOS score reporting reflects the need for a standardized TBI core outcome set.

A Review of Electrolyte, Mineral, and Vitamin Changes After Traumatic Brain Injury

INTRODUCTION

Despite the prevalence of traumatic brain injury (TBI) in both civilian and military populations, the management guidelines developed by the Joint Trauma System involve minimal recommendations for electrolyte physiology optimization during the acute phase of TBI recovery. This narrative review aims to assess the current state of the science for electrolyte and mineral derangements found after TBI.

MATERIALS AND METHODS

We used Google Scholar and PubMed to identify literature on electrolyte derangements caused by TBI and supplements that may mitigate secondary injuries after TBI between 1991 and 2022.

RESULTS

We screened 94 sources, of which 26 met all inclusion criteria. Most were retrospective studies (n = 9), followed by clinical trials (n = 7), observational studies (n = 7), and case reports (n = 2). Of those, 29% covered the use of some type of supplement to support recovery after TBI, 28% covered electrolyte or mineral derangements after TBI, 16% covered the mechanisms of secondary injury after TBI and how they are related to mineral and electrolyte derangements, 14% covered current management of TBI, and 13% covered the potential toxic effects of the supplements during TBI recovery.

CONCLUSIONS

Knowledge of mechanisms and subsequent derangements of electrolyte, mineral, and vitamin physiology after TBI remains incomplete. Sodium and potassium tended to be the most well-studied derangements after TBI. Overall, data involving human subjects were limited and mostly involved observational studies. The data on vitamin and mineral effects were limited, and targeted research is needed before further recommendations can be made. Data on electrolyte derangements were stronger, but interventional studies are needed to assess causation.

Pressure Time Dose as a Representation of Intracranial Pressure Burden and Its Dependency on Intracranial Pressure Waveform Morphology at Different Time Intervals

Intracranial pressure (ICP) burden or pressure time dose (PTD) is a valuable clinical indicator for pending intracranial hypertension, mostly based on threshold exceedance. Pulse frequency and waveform morphology (WFM) of the ICP signal contribute to PTD. The temporal resolution of the ICP signal has a great influence on PTD calculation but has not been systematically studied yet. Hence, the temporal resolution of the ICP signal on PTD calculation is investigated. We retrospectively analysed continuous 48 h ICP recordings with high temporal resolution obtained from 94 patients at the intensive care unit who underwent neurosurgery due to an intracranial haemorrhage and received an intracranial pressure probe (43 females, median age: 72 years, range: 23 to 88 years). The cumulative area under the curve above the threshold of 20 mmHg was compared for different temporal resolutions of the ICP signal (beat-to-beat, 1 s, 300 s, 1800 s, 3600 s). Events with prolonged ICP elevation were compared to those with few isolated threshold exceedances. PTD increased for lower temporal resolutions independent of WFM and frequency of threshold exceedance. PTDbeat-to-beat best reflected the impact of frequency of threshold exceedance and WFM. Events that could be distinguished in PTDbeat-to-beat became magnified more than 7-fold in PTD1s and more than 104 times in PTD1h, indicating an overestimation of PTD. PTD calculation should be standardised, and beat-by-beat PTD could serve as an easy-to-grasp indicator for the impact of frequency and WFM of ICP elevations on ICP burden.

Osmotherapy and the management of traumatic brain injury: still a dilemma

Despite extensive study and use, selecting an osmotherapy agent for traumatic brain injury remains a dilemma. This article explores the challenges in managing patients with traumatic brain injury and the ongoing debate surrounding the efficacy of different hyperosmolar agents as treatment options.

Prediction of Increased Intracranial Pressure in Traumatic Brain Injury Using Quantitative Electroencephalogram in a Porcine Experimental Model

Continuous and non-invasive measurement of intracranial pressure (ICP) in traumatic brain injury (TBI) is important to recognize increased ICP (IICP), which can reduce treatment delays. The purpose of this study was to develop an electroencephalogram (EEG)-based prediction model for IICP in a porcine TBI model. Thirty swine were anaesthetized and underwent IICP by inflating a Foley catheter in the intracranial space. Single-channel EEG data were collected every 6 min in 10 mmHg increments in the ICP from baseline to 50 mmHg. We developed EEG-based models to predict the IICP (equal or over 25 mmHg) using four algorithms: logistic regression (LR), naive Bayes (NB), support vector machine (SVM), and random forest (RF). We assessed the performance of each model based on the accuracy, sensitivity, specificity, and AUC values. The accuracy of each prediction model for IICP was 0.773 for SVM, 0.749 for NB, 0.746 for RF, and 0.706 for LR. The AUC of each model was 0.860 for SVM, 0.824 for NB, 0.802 for RF, and 0.748 for LR. We developed a machine learning prediction model for IICP using single-channel EEG signals in a swine TBI experimental model. The SVM model showed good predictive power with the highest AUC value.

Intracranial peak pressure as a predictor for perioperative mortality after spontaneous intracerebral hemorrhage evacuation and decompressive craniectomy

BACKGROUND

An optimal intracranial pressure (ICP) management target is not well defined in patients with spontaneous intracerebral hemorrhage. The aim of this study was to explore the association between perioperative ICP monitoring parameters and mortality of patients with spontaneous intracerebral hematoma undergoing emergency hematoma removal and decompressive craniectomy (DC), to provide evidence for a target-oriented ICP management.

METHODS

The clinical and radiological features of 176 consecutive patients with spontaneous intracerebral hemorrhage that underwent emergent hematoma evacuation and DC were reviewed. The Glasgow Coma Scale (GCS) and Glasgow Outcome Scale (GOS) scores were assessed 2 weeks after surgery. Multivariate logistic regression analysis was performed to identify predictors for perioperative death.

RESULTS

Forty-four cases (25.0%) were assigned to the ICP group. In patients with an ICP monitor, the median peak ICP value was 25.5 mmHg; 50% of them had a peak ICP value of more than 25 mmHg. The median duration of ICP > 25 mmHg was 2 days. Without a target-specific ICP management, the mortality at 2 weeks after surgery was similar between patients with or without an ICP monitor (27.3% versus 18.2%, p = 0.20). In multivariable analysis, the peak ICP value (OR 1.11, 95% CI 1.004-1.234, p = 0.04) was significantly associated with perioperative death in the ICP group. The area under ROC curve of peak ICP value was 0.78 (95%CI 0.62-0.94) for predicting mortality, with a cut-off value of 31 mmHg.

CONCLUSION

Compared with a persistent hyperintracranial pressure, a high ICP peak value might provide a better prediction for the mortality of patients with spontaneous intracerebral hemorrhage evacuation and DC, suggesting a tailored ICP management protocol to decrease ICP peak value.

Tree-based, two-stage risk factor analysis for postoperative sepsis based on Sepsis-3 criteria in elderly patients: A retrospective cohort study

Background

Sepsis remains the leading cause of postoperative death in elderly patients and is defined as organ dysfunction with proven or suspected infection according to Sepsis-3 criteria. To better avoid potential non-linear associations between the risk factors, we firstly used a tree-based analytic methods to explore the putative risk factors of geriatric sepsis based on the criteria in the study.

Methods

Data of 7,302 surgical patients aged ≥ 65 years at the Third Affiliated Hospital of Sun Yat-sen University from January 2015 to September 2020 were collected. An analytic method that combined tree-based analysis with the method of Mantel-Haenszel and logistic regression was adopted to assess the association between 17 putative risk factors and postoperative sepsis defined by the Sepsis-3 guideline by controlling 16 potential confounding factors.

Results

Among the 16 potential covariates, six major confounders were statistically identified by the tree-based model, including cerebrovascular diseases, preoperative infusion of red blood cells, pneumonia, age ≥ 75, malignant tumor and diabetes. Our analysis indicated that emergency surgery increases the risk of postoperative sepsis in elderly patients by more than six times. The type of surgery is also a crucial risk factor for sepsis, particularly transplantation and neurosurgery. Other risk factors were duration of surgery > 120 min, administration of steroids, hypoalbuminemia, elevated creatinine, blood urea nitrogen, hematocrit, platelets, glucose, white blood cell count, abnormal neutrophil-to-lymphocyte ratio and elevated hsCRP-to-albumin ratio.

Conclusions

Our study uses an effective method to explore some risk factors for postoperative sepsis in elderly by adjusting many potential confounders and it can provide information for intervention design.

Sugar or salt ("SOS"): A protocol for a UK multicentre randomised trial of mannitol and hypertonic saline in severe traumatic brain injury and intracranial hypertension

Hyperosmolar solutions are widely used to treat raised intracranial pressure following severe traumatic brain injury. Although mannitol has historically been the most frequently administered, hypertonic saline solutions are increasingly being used. However, definitive evidence regarding their comparative effectiveness is lacking. The Sugar or Salt Trial is a UK randomised, allocation concealed open label multicentre pragmatic trial designed to determine the clinical and cost-effectiveness of hypertonic saline compared with mannitol in the management of patients with severe traumatic brain injury. Patients requiring intensive care unit admission and intracranial pressure monitoring post-traumatic brain injury will be allocated at random to receive equi-osmolar boluses of either mannitol or hypertonic saline following failure of routine first-line measures to control intracranial pressure. The primary outcome for the study will be the Extended Glasgow Outcome Scale assessed at six months after randomisation. Results will inform current clinical practice in the routine use of hyperosmolar therapy as well as assess the impact of potential side effects. Pre-planned longer term clinical and cost effectiveness analyses will further inform the use of these treatments.

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.

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.

Induced hypernatremia in patients with moderate-to-severe ARDS: a randomized controlled study

Background

Induced hypernatremia and hyperosmolarity is protective in animal models of lung injury. We hypothesized that increasing and maintaining plasma sodium between 145 and 150 mmol/l in patients with moderate-to-severe ARDS would be safe and will reduce lung injury. This was a prospective randomized feasibility study in moderate-to-severe ARDS, comparing standard care with intravenous hypertonic saline to achieve and maintain plasma sodium between 145 and 150 mmol/l for 7 days (HTS group). Both groups of patients were managed with lung protective ventilation and conservative fluid management. The primary outcome was 1-point reduction in lung injury score (LIS) or successful extubation by day 7.

Results

Forty patients were randomized with 20 in each group. Baseline characteristics of severity of illness were well balanced. Patients in the HTS group had higher plasma sodium levels during the first 7 days after randomization when compared with the control group (p = 0.04). Seventy five percent (15/20) of patients in the HTS group were extubated or had ≥ 1-point reduction in LIS compared with 35% (7/20) in the control group (p = 0.02). There was also a decrease in length of mechanical ventilation and hospital length of stay in the HTS group.

Conclusion

We have shown clinical improvement in patients with moderate-to-severe ARDS following induced hypernatremia, suggesting that administration of hypertonic saline is a safe and feasible intervention in patients with moderate-to-severe ARDS. This suggests progress to a phase II study.

Clinical Trial Registration Australian and New Zealand Clinical Trials Registry (ACTRN12615001282572)

Supplementary Information

The online version contains supplementary material available at 10.1186/s40635-021-00399-3.

Safety and Efficacy of 23.4% Sodium Chloride Administered via Peripheral Venous Access for the Treatment of Cerebral Herniation and Intracranial Pressure Elevation

BACKGROUND

Sodium chloride (NaCl) 23.4% solution has been shown to reduce intracranial pressure (ICP) and reverse transtentorial herniation. A limitation of 23.4% NaCl is its high osmolarity (8008 mOsm/l) and the concern for tissue injury or necrosis following extravasation when administered via peripheral venous access. The use of this agent is therefore often limited to central venous or intraosseous routes of administration. Our objective was to evaluate the safety and efficacy of administration of 23.4% NaCl via peripheral venous access compared with administration via central venous access.

METHODS

We reviewed pharmacy records to identify all administrations of 23.4% NaCl at our institution between December 2017 and February 2020. Medical records were then reviewed to identify complications, such as extravasation, soft tissue injury or necrosis, hypotension (mean arterial pressure less than 65 mm Hg), pulmonary edema, hemolysis, and osmotic demyelination. We also compared the change in physiological variables, such as ICP, mean arterial pressure, cerebral perfusion pressure, and heart rate, as well as laboratory values, such as sodium, chloride, bicarbonate, creatinine, and hemoglobin, following administration of 23.4% NaCl via the peripheral and central venous routes.

RESULTS

We identified 299 administrations of 23.4% NaCl (242 central and 57 peripheral) in 141 patients during the study period. There was no documented occurrence of soft tissue injury or necrosis in any patient. One patient developed hypotension following central administration. Among the 38 patients with ICP monitoring at the time of drug administration, there was no significant difference in median ICP reduction (- 13 mm Hg [central] vs. - 24 mm Hg [peripheral], p = 0.21) or cerebral perfusion pressure augmentation (16 mm Hg [central] vs. 15 mm Hg [peripheral], p = 0.87) based on route of administration.

CONCLUSIONS

Peripheral venous administration of 23.4% NaCl is safe and achieves a reduction in ICP equivalent to that achieved by administration via central venous access.

Non-invasive detection of intracranial pressure related to the optic nerve

Intracranial pressure (ICP) is associated with a variety of diseases. Early diagnosis and the timely intervention of elevated ICP are effective means to clinically reduce the morbidity and mortality of some diseases. The detection and judgment of reduced ICP are beneficial to glaucoma doctor and neuro ophthalmologist to diagnose optic nerve disease earlier. It is important to evaluate and monitor ICP clinically. Although invasive ICP detection is the gold standard, it can have complications. Most non-invasive ICP tests are related to the optic nerve and surrounding tissues due to their anatomical characteristics. Ultrasound, magnetic resonance imaging, transcranial Doppler, papilledema on optical coherence tomography, visual evoked potential, ophthalmodynamometry, the assessment of spontaneous retinal venous pulsations, and eye-tracking have potential for application. Although none of these methods can completely replace invasive technology; however, its repeatable, low risk, high accuracy, gradually attracted people's attention. This review summarizes the non-invasive ICP detection methods related to the optic nerve and the role of the diagnosis and prognosis of neurological disorders and glaucoma. We discuss the advantages and challenges and predict possible areas of development in the future.

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.

Traumatic Brain Injury Outcomes in 10 Asian Pediatric ICUs: A Pediatric Acute and Critical Care Medicine Asian Network Retrospective Study

OBJECTIVES

Traumatic brain injury remains an important cause of death and disability. We aim to report the epidemiology and management of moderate to severe traumatic brain injury in Asian PICUs and identify risk factors for mortality and poor functional outcomes.

DESIGN

A retrospective study of the Pediatric Acute and Critical Care Medicine Asian Network moderate to severe traumatic brain injury dataset collected between 2014 and 2017.

SETTING

Patients were from the participating PICUs of Pediatric Acute and Critical Care Medicine Asian Network.

PATIENTS

We included children less than 16 years old with a Glasgow Coma Scale less than or equal to 13.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We obtained data on patient demographics, injury circumstances, and PICU management. We performed a multivariate logistic regression predicting for mortality and poor functional outcomes. We analyzed 380 children with moderate to severe traumatic brain injury. Most injuries were a result of road traffic injuries (174 [45.8%]) and falls (160 [42.1%]). There were important differences in temperature control, use of antiepileptic drugs, and hyperosmolar agents between the sites. Fifty-six children died (14.7%), and 104 of 324 survivors (32.1%) had poor functional outcomes. Poor functional outcomes were associated with non-high-income sites (adjusted odds ratio, 1.90; 95% CI, 1.11-3.29), Glasgow Coma Scale less than 8 (adjusted odds ratio, 4.24; 95% CI, 2.44-7.63), involvement in a road traffic collision (adjusted odds ratio, 1.83; 95% CI, 1.04-3.26), and presence of child abuse (adjusted odds ratio, 2.75; 95% CI, 1.01-7.46).

CONCLUSIONS

Poor functional outcomes are prevalent after pediatric traumatic brain injury in Asia. There is an urgent need for further research in these high-risk groups.

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.

Severe traumatic brain injury management in Tanzania: analysis of a prospective cohort

OBJECTIVE

Given the high burden of neurotrauma in low- and middle-income countries (LMICs), in this observational study, the authors evaluated the treatment and outcomes of patients with severe traumatic brain injury (TBI) accessing care at the national neurosurgical institute in Tanzania.

METHODS

A neurotrauma registry was established at Muhimbili Orthopaedic Institute, Dar-es-Salaam, and patients with severe TBI admitted within 24 hours of injury were included. Detailed emergency department and subsequent medical and surgical management of patients was recorded. Two-week mortality was measured and compared with estimates of predicted mortality computed with admission clinical variables using the Corticoid Randomisation After Significant Head Injury (CRASH) core model.

RESULTS

In total, 462 patients (mean age 33.9 years) with severe TBI were enrolled over 4.5 years; 89% of patients were male. The mean time to arrival to the hospital after injury was 8 hours; 48.7% of patients had advanced airway management in the emergency department, 55% underwent cranial CT scanning, and 19.9% underwent surgical intervention. Tiered medical therapies for intracranial hypertension were used in less than 50% of patients. The observed 2-week mortality was 67%, which was 24% higher than expected based on the CRASH core model.

CONCLUSIONS

The 2-week mortality from severe TBI at a tertiary referral center in Tanzania was 67%, which was significantly higher than the predicted estimates. The higher mortality was related to gaps in the continuum of care of patients with severe TBI, including cardiorespiratory monitoring, resuscitation, neuroimaging, and surgical rates, along with lower rates of utilization of available medical therapies. In ongoing work, the authors are attempting to identify reasons associated with the gaps in care to implement programmatic improvements. Capacity building by twinning provides an avenue for acquiring data to accurately estimate local needs and direct programmatic education and interventions to reduce excess in-hospital mortality from TBI.

Hypertonic Saline Versus Mannitol for Traumatic Brain Injury: A Systematic Review and Meta-analysis With Trial Sequential Analysis

BACKGROUND

Mannitol and hypertonic saline are widely used to treat raised intracranial pressure (ICP) after traumatic brain injury (TBI), but the clinical superiority of one over the other has not been demonstrated.

METHODS

According to the PRISMA statement, this meta-analysis reports on randomized controlled trials investigating hypertonic saline compared with mannitol in the treatment of elevated ICP following TBI. The protocol for the literature searches (Medline, Embase, Central databases), quality assessment, endpoints (mortality, favorable outcome, brain perfusion parameters), and statistical analysis plan (including a trial sequential analysis) were prospectively specified and registered on the PROSPERO database (CRD42017057112).

RESULTS

A total of 12 randomized controlled trials with 464 patients were eligible for inclusion in this analysis. Although there was a nonsignificant trend in favor of hypertonic saline, there were no significant differences in mortality between the 2 treatments (relative risk [RR]: 0.69, 95% confidence interval [CI]: 0.45, 1.04; P=0.08). There were also no significant differences in favorable neurological outcome between hypertonic saline (HS) and mannitol (RR: 1.28, 95% CI: 0.86, 1.90; P=0.23). There was no difference in ICP at 30 to 60 minutes after treatment (mean difference [MD]: -0.19 mm Hg, 95% CI: -0.54, 0.17; P=0.30), whereas ICP was significantly lower after HS compared with mannitol at 90 to 120 minutes (MD: -2.33 mm Hg, 95% CI: -3.17, -1.50; P<0.00001). Cerebral perfusion pressure was higher between 30 to 60 and 90 to 120 minutes after treatment with HS compared with after treatment with mannitol (MD: 5.48 mm Hg, 95% CI: 4.84, 6.12; P<0.00001 and 9.08 mm Hg, 95% CI: 7.54, 10.62; P<0.00001, respectively). Trial sequential analysis showed that the number of cases was insufficient to produce reliable statements on long-term outcomes.

CONCLUSION

There are indications that HS might be superior to mannitol in the treatment of TBI-related raised ICP. However, there are insufficient data to reach a definitive conclusion, and further studies are warranted.

Effects of two different doses of 3% hypertonic saline with mannitol during decompressive craniectomy following traumatic brain injury: A prospective, controlled study

Background and Aims:

The current study was designed to compare the effects of two different doses of 3% hypertonic saline with mannitol on intraoperative events during decompressive craniectomy in traumatic brain injury (TBI). Primary outcome measures included assessment of intraoperative brain relaxation, hemodynamic variables, and serum electrolytes. Effect on the postoperative outcome, in terms of the Glasgow coma scale (GCS), length of stay in the ICU, and mortality were the secondary outcome measures.

Material and Methods:

Ninety patients with TBI undergoing craniotomy were enrolled. Patients were assigned to receive 300 mL (328 mOsm) of mannitol (n = 26, M) only or 300 mL of mannitol with 150 mL (482 mOsm) of 3% HS (n = 35, HS₁) or with 300 mL (636 mOsm) of 3% HS (n = 29, HS₂). Brain relaxation was assessed and if required, a rescue dose of mannitol (150 mL) was given. GCS was assessed preoperatively, 24 h postoperatively, and at the time of discharge from the ICU and total duration of stay was noted.

Results:

Acceptable brain relaxation was observed in 89.66% (n = 26, HS₂) and 80% (n = 28, HS₁) patients as compared to 46.1% (n = 12, M) patients (P < 0.001) with significantly less number of patients requiring rescue doses of mannitol in groups HS₁ and HS₂(n = 7 and 3, respectively) as compared to group M (n = 14) (P < 0.05). There was a significant improvement in GCS at 24 h and at the time of discharge from the ICU in patients with a severe head injury in group HS₂ (P = 0.029). In patients with moderate head injury there was a significant improvement in GCS at the time of discharge among all the three groups (P < 0.05).

Conclusion:

Increasing osmotic load by addition of 3% HS to mannitol provides better intraoperative brain relaxation than mannitol alone during decompressive craniectomy. An addition of 300mL 3% HS was found to be more effective in improving GCS in patients with severe TBI.

23.4% Sodium Chloride Versus Mannitol for the Reduction of Intracranial Pressure in Patients With Traumatic Brain Injury: A Single-Center Retrospective Cohort Study

BACKGROUND

Intermittent doses of mannitol or hypertonic saline are recommended to treat elevated intracranial pressure (ICP). However, it is unclear if one agent is more effective than the other. Previous studies have compared mannitol and hypertonic saline in reduction of ICP, with conflicting results. However, no study thus far has compared 23.4% sodium chloride with mannitol.

OBJECTIVE

The objective of this study was to determine the difference in absolute reduction of ICP 60 minutes after infusion of 23.4% sodium chloride versus mannitol.

METHODS

This was a single-center retrospective cohort study that included patients at least 16 years old admitted to the trauma/surgical intensive care unit between August 8, 2016, and August 30, 2018, who received either 23.4% sodium chloride 30 mL and/or mannitol 0.5 g/kg and had an ICP monitor or external ventricular drain in place. The primary outcome was absolute reduction in ICP 60 minutes after infusion of hyperosmolar therapy.

RESULTS

In all, 31 patients and 162 doses of hyperosmolar therapy were included in the analysis. There was no statistically significant difference in the primary end point of absolute reduction of ICP 60 minutes after infusion of hyperosmolar therapy comparing 23.4% sodium chloride 30 mL with 0.5 g/kg mannitol (P = 0.2929). There was no statistically significant difference found for any secondary end points.

CONCLUSION AND RELEVANCE

No difference was found for absolute reduction of ICP at 30, 60, and 120 minutes, respectively, after infusion of hyperosmolar agent or time to next elevated ICP. Patient-specific parameters should be used to guide the choice of hyperosmolar agent to be administered.

Escalate and De-Escalate Therapies for Intracranial Pressure Control in Traumatic Brain Injury

Severe traumatic brain injury (TBI) is frequently associated with an elevation of intracranial pressure (ICP), followed by cerebral perfusion pressure (CPP) reduction. Invasive monitoring of ICP is recommended to guide a step-by-step “staircase approach” which aims to normalize ICP values and reduce the risks of secondary damage. However, if such monitoring is not available clinical examination and radiological criteria should be used. A major concern is how to taper the therapies employed for ICP control. The aim of this manuscript is to review the criteria for escalating and withdrawing therapies in TBI patients. Each step of the staircase approach carries a risk of adverse effects related to the duration of treatment. Tapering of barbiturates should start once ICP control has been achieved for at least 24 h, although a period of 2–12 days is often required. Administration of hyperosmolar fluids should be avoided if ICP is normal. Sedation should be reduced after at least 24 h of controlled ICP to allow neurological examination. Removal of invasive ICP monitoring is suggested after 72 h of normal ICP. For patients who have undergone surgical decompression, cranioplasty represents the final step, and an earlier cranioplasty (15–90 days after decompression) seems to reduce the rate of infection, seizures, and hydrocephalus.

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.

Prehospital fluid administration in patients with severe traumatic brain injury: A systematic review and meta-analysis

BACKGROUND

Prehospital management of severe traumatic brain injury (TBI) focuses on preventing secondary brain injury. Therefore, hypotension should be prevented, or if present, should be promptly treated in order to maintain optimal cerebral perfusion pressure. Fluid resuscitation is a traditional mainstay in the prehospital treatment of hypotension, however, the choice of fluid type that is to be administered in the prehospital setting is the subject of an on-going debate. This systematic review and meta-analysis was therefore performed to assess the effect of different fluid types on outcome in patients with severe TBI.

METHODS

PubMed, Embase and Web of Science were searched for articles up to March 2020. Studies comparing two or more prehospital administered fluid types with suspected or confirmed severe TBI were deemed eligible for inclusion. Studied outcomes were mortality and (extended) Glasgow Outcome Scale (GOS). The meta-analysis tested for differences in survival between hypertonic saline (HTS) and normotonic crystalloids (i.e. normal saline or Lactated Ringer's) and between hypertonic saline with dextran (HSD) and normotonic crystalloids. The systematic review is registered in the PROSPERO register with number CRD42020140423.

RESULTS

This literature search yielded a total of 519 articles, of which 12 were included in the systematic review and 6 were included in the meta-analysis. Eleven studies found no statistically significant difference in survival between patients treated with different fluid types (e.g. normal saline and hypertonic saline). All studies assessing neurological outcome, measured through (extended) GOS, found no statistically significant difference between different fluid types. Meta-analysis showed no better survival for patients treated with HSD, when compared to normotonic crystalloids (overall RR 0.99, 95% CI 0.93-1.06). Moreover, HTS compared to normotonic crystalloids does not result in a better survival (overall RR 1.04, 95% CI 0.97-1.12).

CONCLUSIONS

This systematic review and meta-analysis did not demonstrate a survival or neurological benefit for one specific fluid type administered in the prehospital setting.

Current fluid and blood product availability in veterinary setting: a survey of UK small animal practices

OBJECTIVES

To investigate and discuss current fluid and blood products stocked in small animal practices in the UK.

METHODS

An online survey was circulated to small animal veterinary practices across the UK. The survey included questions regarding the level of hospital care provided, the type of fluid and blood component products stocked, the most frequently restocked products, and the available options in the event that blood products were required but not stocked.

RESULTS

There were 423 responses including 27 duplicates. The remaining 396 respondents represented a spectrum of practices including 19 referral practices. Crystalloids were stocked in all practices. Lactated Ringer's solution was the most frequently re-stocked product in 355 of 396 (90%) of practices. Where synthetic colloids were stocked, gelatin-based colloids (155/178 [87%]) were stocked in preference to hydroxyethyl starches (23/178 [13%]). Blood products were stocked by 81 of 396 (20%) of practices. If a blood product was required but not stocked, 31% of practices would use a pet blood banking service, 28% would use their own blood donors, and 21% would refer.

CLINICAL SIGNIFICANCE

This study provides an insight into the fluid and blood products stocked and used by a selection of veterinary practices within the UK and serves as a baseline for ongoing research and decision-making in both veterinary practice and industry.

Equimolar doses of hypertonic agents (saline or mannitol) in the treatment of intracranial hypertension after severe traumatic brain injury

BACKGROUND

Mannitol and hypertonic saline (HTS) are effective in reducing intracranial pressure (ICP) after severe traumatic brain injury (TBI). However, their efficacy on the ICP has not been evaluated rigorously.

OBJECTIVE

To evaluate the efficacy of repeated bolus dosing of HTS and mannitol in similar osmotic burdens to treat intracranial hypertension (ICH) in patients with severe TBI.

METHODS

The authors used an alternating treatment protocol to evaluate the efficacy of HTS with that of mannitol given for ICH episodes in patients treated for severe TBI at their hospital during 2017 to 2019. Doses of similar osmotic burdens (20% mannitol, 2 ml/kg, or 10% HTS, 0.63 ml/kg, administered as a bolus via a central venous catheter, infused over 15 minutes) were given alternately to the individual patient with severe TBI during ICH episodes. The choice of osmotic agents for the treatment of the initial ICH episode was determined on a randomized basis; osmotic agents were alternated for every subsequent ICH episode in each individual patient. intracranial pressure (ICP), mean arterial pressure (MAP), and cerebral perfusion pressure (CPP) were continuously monitored between the beginning of each osmotherapy and the return of ICP to 20 mm Hg. The duration of the effect of ICP reduction (between the beginning of osmotherapy and the return of ICP to 20 mm Hg), the maximum reduction of ICP and its time was recorded after each dose. Serum sodium and plasma osmolality were measured before, 0.5 hours and 3 hours after each dose. Adverse effects such as central pontine myelinolysis (CPM), severe fluctuations of serum sodium and plasma osmolality were assessed to evaluate the safety of repeated dosing of HTS and mannitol.

RESULTS

Eighty three patients with severe TBI were assessed, including 437 ICH episodes, receiving 236 doses of HTS and 221 doses of mannitol totally. There was no significant difference between equimolar HTS and mannitol boluses on the magnitude of ICP reduction, the duration of effect, and the time to lowest ICP achieved (P > .05). The proportion of efficacious boluses was higher for HTS than for mannitol (P = .016), as was the increase in serum sodium (P = .038). The serum osmolality increased immediately after osmotherapy with a significant difference (P = .017). No cases of CPM were detected.

CONCLUSION

Repeat bolus dosing of 10% HTS and 20% mannitol appears to be significantly and similarly effective for treating ICH in patients with severe TBI. The proportion of efficacious doses of HTS on ICP reduction may be higher than mannitol.

Management and Challenges of Severe Traumatic Brain Injury

Traumatic brain injury (TBI) is the leading cause of death and disability in trauma patients, and can be classified into mild, moderate, and severe by the Glasgow coma scale (GCS). Prehospital, initial emergency department, and subsequent intensive care unit (ICU) management of severe TBI should focus on avoiding secondary brain injury from hypotension and hypoxia, with appropriate reversal of anticoagulation and surgical evacuation of mass lesions as indicated. Utilizing principles based on the Monro-Kellie doctrine and cerebral perfusion pressure (CPP), a surrogate for cerebral blood flow (CBF) should be maintained by optimizing mean arterial pressure (MAP), through fluids and vasopressors, and/or decreasing intracranial pressure (ICP), through bedside maneuvers, sedation, hyperosmolar therapy, cerebrospinal fluid (CSF) drainage, and, in refractory cases, barbiturate coma or decompressive craniectomy (DC). While controversial, direct ICP monitoring, in conjunction with clinical examination and imaging as indicated, should help guide severe TBI therapy, although new modalities, such as brain tissue oxygen (PbtO₂) monitoring, show great promise in providing strategies to optimize CBF. Optimization of the acute care of severe TBI should include recognition and treatment of paroxysmal sympathetic hyperactivity (PSH), early seizure prophylaxis, venous thromboembolism (VTE) prophylaxis, and nutrition optimization. Despite this, severe TBI remains a devastating injury and palliative care principles should be applied early. To better affect the challenging long-term outcomes of severe TBI, more and continued high quality research is required.

Intracranial Pressure Monitoring Signals After Traumatic Brain Injury: A Narrative Overview and Conceptual Data Science Framework

Continuous intracranial pressure (ICP) monitoring is a cornerstone of neurocritical care after severe brain injuries such as traumatic brain injury and acts as a biomarker of secondary brain injury. With the rapid development of artificial intelligent (AI) approaches to data analysis, the acquisition, storage, real-time analysis, and interpretation of physiological signal data can bring insights to the field of neurocritical care bioinformatics. We review the existing literature on the quantification and analysis of the ICP waveform and present an integrated framework to incorporate signal processing tools, advanced statistical methods, and machine learning techniques in order to comprehensively understand the ICP signal and its clinical importance. Our goals were to identify the strengths and pitfalls of existing methods for data cleaning, information extraction, and application. In particular, we describe the use of ICP signal analytics to detect intracranial hypertension and to predict both short-term intracranial hypertension and long-term clinical outcome. We provide a well-organized roadmap for future researchers based on existing literature and a computational approach to clinically-relevant biomedical signal data.

Hypertonic Saline is Superior to Mannitol for the Combined Effect on Intracranial Pressure and Cerebral Perfusion Pressure Burdens in Patients With Severe Traumatic Brain Injury

BACKGROUND

Hypertonic saline (HTS) and mannitol are effective in reducing intracranial pressure (ICP) after severe traumatic brain injury (TBI). However, their simultaneous effect on the cerebral perfusion pressure (CPP) and ICP has not been studied rigorously.

OBJECTIVE

To determine the difference in effects of HTS and mannitol on the combined burden of high ICP and low CPP in patients with severe TBI.

METHODS

We performed a case-control study using prospectively collected data from the New York State TBI-trac® database (Brain Trauma Foundation, New York, New York). Patients who received only 1 hyperosmotic agent, either mannitol or HTS for raised ICP, were included. Patients in the 2 groups were matched (1:1 and 1:2) for factors associated with 2-wk mortality: age, Glasgow Coma Scale score, pupillary reactivity, hypotension, abnormal computed tomography scans, and craniotomy. Primary endpoint was the combined burden of ICPhigh (> 25 mm Hg) and CPPlow (< 60 mm Hg).

RESULTS

There were 25 matched pairs for 1:1 comparison and 24 HTS patients matched to 48 mannitol patients in 1:2 comparisons. Cumulative median osmolar doses in the 2 groups were similar. In patients treated with HTS compared to mannitol, total number of days (0.6 ± 0.8 vs 2.4 ± 2.3 d, P < .01), percentage of days with (8.8 ± 10.6 vs 28.1 ± 26.9%, P < .01), and the total duration of ICPhigh + CPPlow (11.12 ± 14.11 vs 30.56 ± 31.89 h, P = .01) were significantly lower. These results were replicated in the 1:2 match comparisons.

CONCLUSION

HTS bolus therapy appears to be superior to mannitol in reduction of the combined burden of intracranial hypertension and associated hypoperfusion in severe TBI patients.

Effects of hypertonic saline versus mannitol in patients with traumatic brain injury in prehospital, emergency department, and intensive care unit settings: a systematic review and meta-analysis

BACKGROUND

Intracranial pressure control has long been recognized as an important requirement for patients with severe traumatic brain injury. Hypertonic saline has drawn attention as an alternative to mannitol in this setting. The aim of this study was to assess the effects of hypertonic saline versus mannitol on clinical outcomes in patients with traumatic brain injury in prehospital, emergency department, and intensive care unit settings by systematically reviewing the literature and synthesizing the evidence from randomized controlled trials.

METHODS

We searched the MEDLINE database, the Cochrane Central Register of Controlled Trials, and the Igaku Chuo Zasshi (ICHUSHI) Web database with no date restrictions. We selected randomized controlled trials in which the clinical outcomes of adult patients with traumatic brain injury were compared between hypertonic saline and mannitol strategies. Two investigators independently screened the search results and conducted the data extraction. The primary outcome was all-cause mortality. The secondary outcomes were 90-day and 180-day mortality, good neurological outcomes, reduction in intracranial pressure, and serum sodium level. Random effects estimators with weights calculated by the inverse variance method were used to determine the pooled risk ratios.

RESULTS

A total of 125 patients from four randomized trials were included, and all the studies were conducted in the intensive care unit. Among 105 patients from three trials that evaluated the primary outcome, 50 patients were assigned to the hypertonic saline group and 55 patients were assigned to the mannitol group. During the observation period, death was observed for 16 patients in the hypertonic saline group (32.0%) and 21 patients in the mannitol group (38.2%). The risks were not significant between the two infusion strategies (pooled risk ratio, 0.82; 95% confidence interval, 0.49-1.37). There were also no significant differences between the two groups in the other secondary outcomes. However, the certainty of the evidence was rated very low for all outcomes.

CONCLUSIONS

Our findings revealed no significant difference in the all-cause mortality rates between patients receiving hypertonic saline or mannitol to control intracranial pressure. Further investigation is warranted because we only included a limited number of studies.

Hypertonic saline mediates the NLRP3/IL-1β signaling axis in microglia to alleviate ischemic blood-brain barrier permeability by downregulating astrocyte-derived VEGF in rats

Introduction

The aim of this study was to explore whether the antibrain edema of hypertonic saline (HS) is associated with alleviating ischemic blood‐brain barrier (BBB) permeability by downregulating astrocyte‐derived vascular endothelial growth factor (VEGF), which is mediated by microglia‐derived NOD‐like receptor protein 3 (NLRP3) inflammasome.

Methods

The infarct volume and BBB permeability were detected. The protein expression level of VEGF in astrocytes in a transient focal brain ischemia model of rats was evaluated after 10% HS treatment. Changes in the NLRP3 inflammasome, IL‐1β protein expression, and the interleukin‐1 receptor (IL1R1)/pNF‐кBp65/VEGF signaling pathway were determined in astrocytes.

Results

HS alleviated the BBB permeability, reduced the infarct volume, and downregulated the expression of VEGF in astrocytes. HS downregulates IL‐1β expression by inhibiting the activation of the NLRP3 inflammasome in microglia and then downregulates VEGF expression by inhibiting the phosphorylation of NF‐кBp65 mediated by IL‐1β in astrocytes.

Conclusions

HS alleviated the BBB permeability, reduced the infarct volume, and downregulated the expression of VEGF in astrocytes. HS downregulated IL‐1β expression via inhibiting the activation of the NLRP3 inflammasome in microglia and then downregulated VEGF expression through inhibiting the phosphorylation of NF‐кBp65 mediated by IL‐1β in astrocytes.

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.

Hyperosmolar Therapy in Pediatric Severe Traumatic Brain Injury-A Systematic Review

OBJECTIVES

Traumatic brain injury is a leading cause of hospital visits for children. Hyperosmolar therapy is often used to treat severe traumatic brain injury. Hypertonic saline is used predominantly, yet there remains disagreement about whether hypertonic saline or mannitol is more effective.

DATA SOURCES

Literature search was conducted using Pubmed, Cochrane, and Embase. Systematic review followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

STUDY SELECTION

Retrospective and prospective studies assessing use of hyperosmolar therapy in pediatric patients with severe traumatic brain injury were included.

DATA EXTRACTION

Two independent authors performed article review. Two-thousand two-hundred thirty unique articles were initially evaluated, 11 were included in the final analysis, with a total of 358 patients. Study quality was assessed using Modified Newcastle-Ottawa Scale and Jadad score.

DATA SYNTHESIS

Of the 11 studies, all evaluated hypertonic saline and four evaluated both hypertonic saline and mannitol. Nine reported that hypertonic saline lowered intracranial pressure and two reported that mannitol lowered intracranial pressure. The studies varied significantly in dose, concentration, and administrations schedule for both hypertonic saline and mannitol. Five studies were prospective, but only one directly compared mannitol to hypertonic saline. The prospective comparison study found no difference in physiologic outcomes. Clinical outcomes were reported using different measures across studies. For hypertonic saline-treated patients, mechanical ventilation was required for 6.9-9 days, decompressive craniectomy was required for 6.25-29.3% of patients, ICU length of stay was 8.0-10.6 days, in-hospital mortality was 10-48%, and 6-month mortality was 7-17%. In mannitol-treated patients, ICU length of stay was 9.5 days, in-hospital mortality was 56%, and 6-month mortality was 19%.

CONCLUSIONS

Both hypertonic saline and mannitol appear to lower intracranial pressure and improve clinical outcomes in pediatric severe traumatic brain injury, but the evidence is extremely fractured both in the method of treatment and in the evaluation of outcomes. Given the paucity of high-quality data, it is difficult to definitively conclude which agent is better or what treatment protocol to follow.

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.

Hypertonic saline versus mannitol for the treatment of increased intracranial pressure in traumatic brain injury

BACKGROUND

Increased intracranial pressure (ICP) occurring after traumatic brain injury (TBI) is associated with increased morbidity and mortality. If appropriate treatments are not initiated, brain herniation can occur and lead to death. Previously, the Brain Trauma Foundation recommended mannitol as the first-choice hyperosmolar agent. However, in 2016, they retracted this recommendation, citing a lack of sufficient supporting evidence. Current research shows that hypertonic saline (HTS) also decreases ICP.

OBJECTIVES

To compare the efficacy of HTS and mannitol in lowering ICP in patients with TBI.

DATA SOURCES

A search was conducted up to June 1, 2019, using PubMed, Embase, CINAHL, and Web of Science. Selected articles compared mannitol and HTS in adults with TBI, with the measured outcome of reduced ICP. Four meta-analyses, three randomized controlled trials, and one retrospective cohort study met the inclusion criteria.

CONCLUSIONS

Hypertonic saline is an effective alternative to mannitol for increased ICP. Three studies suggested HTS may be superior to mannitol. Conclusions were limited by sample size and methodological differences, such as varying concentrations and doses, and inclusion of patients without TBI in their studies.

IMPLICATIONS FOR PRACTICE

Evidence demonstrates HTS to be as effective as mannitol for ICP reduction. Further research in a large multicenter clinical trial is needed to compare these two agents for superiority in the management of increased ICP. Providers should consider the properties of each agent, adverse effects, and potential benefits when selecting a hyperosmotic agent.

The Value of Managing Severe Traumatic Brain Injury During the Perioperative Period Using Intracranial Pressure Monitoring

This study aimed to investigate the clinical efficacy of intracranial pressure (ICP) monitoring regarding the perioperative management of patients with severe traumatic brain injury (sTBI). This was a cohort study performed between Jan 2013 and Jan 2016 and included all patients with sTBI. All patients were split into ICP monitoring and non-ICP monitoring groups. The primary outcomes were in-hospital mortality and Glasgow Outcome Scale (GOS) scores 6 months after injury, whereas the secondary outcomes include rate of successful nonsurgical treatment, rate of decompression craniotomy (DC), the length of stay in the ICU, and the hospital and medical expenses. This retrospective analysis included 246 ICP monitoring sTBI patients and 695 without ICP monitoring sTBI patients. No significant difference between groups regarding patient demographics. All patients underwent a GOS assessment 6 months after surgery. Compared to the non-ICP monitoring group, a lower in-hospital mortality (20.3% vs 30.2%, P < 0.01) and better GOS scores after 6 months (3.3 ± 1.6 vs 2.9 ± 1.6, P < 0.05) with ICP monitoring. In addition, patients in the ICP monitoring group had a lower craniotomy rate (41.1% vs 50.9%, P < 0.01) and a lower DC rate (41.6% vs 55.9%, P < 0.05) than those in the non-ICP monitoring group. ICU length of stay (12.4 ± 4.0 days vs 10.2 ± 4.8 days, P < 0.01) was shorter in the non-ICP monitoring group, but it had no difference between 2 groups on total length of hospital stay (22.9 ± 13.6 days vs 24.6 ± 13.6 days, P = 0.108); Furthermore, the medical expenses were significantly higher in the non-ICP monitoring group than the ICP monitoring group (11.5 ± 7.2 vs 13.3 ± 9.1, P < 0.01). Intracranial pressure monitoring has beneficial effects for sTBI during the perioperative period. It can reduce the in-hospital mortality and DC rate and also can improve the 6-month outcomes. However, this was a single institution and observational study, well-designed, multicenter, randomized control trials are needed to evaluate the effects of ICP monitoring for perioperative sTBI patients.

A Retrospective Study of Intracranial Pressure in Head-Injured Patients Undergoing Decompressive Craniectomy: A Comparison of Hypertonic Saline and Mannitol

Objective: The impact of hypertonic saline (HTS) on the control of increased intracranial pressure (ICP) in head-injured patients undergoing decompressive craniectomy (DC) has yet to be established. The current retrospective study was conducted to compare the effect of HTS and mannitol on lowering the ICP burden of these patients.

Methods: We reviewed data on patients who had sustained a traumatic brain injury (TBI) and were admitted to the First People's Hospital of Kunshan between January 1, 2012, and August 31, 2017. Patients who received only one type of hyperosmotic agent, 3% HTS or 20% mannitol, after DC were included. The daily ICP burden (h/day) and response to the hyperosmolar agent were used as primary outcome measures. The numbers of days in the intensive care unit and in the hospital, and the 2-weeks mortality rates were also compared between the groups.

Results: The 30 patients who received 3% HTS only and the 30 who received 20% mannitol only were identified for approximate matching and additional data analyses. The demographic characteristics of the patients in the two groups were comparable, but the daily ICP burden was significantly lower in the HTS group than in the mannitol group (0.89 ± 1.02 h/day vs. 2.11 ± 2.95 h/day, respectively; P = 0.038). The slope of the reduction in ICP in response to a bolus dose at baseline was higher with HTS than with mannitol (P = 0.001). However, the between-group difference in the 2-weeks mortality rates was not statistically significant (2 [HTS] vs. 1 [mannitol]; P = 0.554).

Conclusion: When used in equiosmolar doses, the reduction in the ICP of TBI patients achieved with 3% HTS was superior to that achieved with 20% mannitol after DC. However, this advantage did not seem to confer any additional benefit terms of short-term mortality.

Comparison of effect of dexmedetomidine and lidocaine on intracranial and systemic hemodynamic response to chest physiotherapy and tracheal suctioning in patients with severe traumatic brain injury

PURPOSE

Chest physiotherapy and tracheal suction cause sympathetic stimulation and increase heart rate (HR), mean arterial pressure (MAP) and intracranial pressure (ICP) which may have deleterious effect in the head injured. We planned to compare the effect of intravenous dexmedetomidine and lidocaine on intracerebral and systemic hemodynamic response to chest physiotherapy (CP) and tracheal suctioning (TS) in patients with severe traumatic brain injury (sTBI).

METHODS

Prospective, randomized study in patients with sTBI, 18-60 years of age, undergoing mechanical ventilation and intraparenchymal ICP monitoring. Patients were randomized to receive either iv dexmedetomidine 0.5 mcg/kg (group I; n = 30) or iv lidocaine 2 mg/kg (group II; n = 30) over 10 min. After infusion of test drug, CP with vibrator and manual compression was performed for 2 min and TS was done over next 15-20 s. The hemodynamic response was recorded before, during and at interval of 1 min for 10 min after CP and TS. A 20% change in hemodynamic parameters was considered significant.

RESULTS

The baseline hemodynamic (HR, MAP), intracranial (ICP, CPP) and respiratory (SPO₂, AWP_peak) parameters were normal and comparable in both the groups. After dexmedetomidine infusion, MAP and CPP decreased significantly from baseline value. In group II, there was no significant change in HR, MAP, ICP and CPP. At end of CP and TS, HR, MAP and CPP in group I was lower as compared to group II. During the 10-min observation period following CP and TS, MAP and CPP in group I remained significantly lower as compared to baseline and group II. There was no significant change in value of other measured parameters.

CONCLUSIONS

Both dexmedetomidine and lidocaine were effective to blunt rise in HR, MAP and ICP in response to CP and TS in patients with sTBI. However, intravenous dexmedetomidine caused significant decrease in MAP and CPP as compared to the baseline and lidocaine.

Value of Ventricular Intracranial Pressure Monitoring for Traumatic Bifrontal Contusions

OBJECTIVE

To investigate clinical efficacy of and optimal therapeutic strategy for ventricular intracranial pressure monitoring (V-ICPM) in patients with traumatic bifrontal contusions (TBCs).

METHODS

From 8760 patients with traumatic brain injury treated between January 2010 and January 2016, a retrospective analysis was performed on 105 patients with TBCs who underwent V-ICPM and 282 patients with TBCs who did not. All patients underwent treatment at the 101st Hospital of PLA, Wuxi, China. Rates of successful conservative treatment, decompressive craniectomy, and bifrontal craniotomy; incidence of neurologic dysfunction; length of stay; and medical expenses were compared between groups.

RESULTS

Glasgow Outcome Scale was used to assess all patients during follow-up (range, 6 months to 5.5 years). There were no significant differences in prognosis between the 2 groups (P = 0.100). Compared with the patients who did not undergo V-ICPM, the V-ICPM group had a significantly better successful conservative treatment rate (64.8% vs. 47.2%, P = 0.002), decompressive craniectomy rate (8.1% vs. 22.1%, P = 0.008), and bifrontal craniotomy rate (5.7% vs. 15.6%, P = 0.01); shorter length of stay (P = 0.000); and lower medical expenses (P = 0.004).

CONCLUSIONS

Patients with TBCs should be strictly, closely, and dynamically observed by neurosurgery intensive care unit physicians and nurses. Patients should undergo ventricular intracranial pressure probe implantation in a timely manner. V-ICPM can help optimize treatment. Although V-ICPM did not significantly improve the prognosis of patients, it had many other advantages. V-ICPM warrants further clinical research and may be beneficial for patients with TBCs.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

The influence of acute elevations in plasma osmolality and serum sodium on sympathetic outflow and blood pressure responses to exercise

Elevated plasma osmolality (pOsm) has been shown to increase resting sympathetic nerve activity in animals and humans. The present study tested the hypothesis that increases in pOsm and serum sodium (sNa⁺) concentration would exaggerate muscle sympathetic nerve activity (MSNA) and blood pressure (BP) responses to handgrip (HG) exercise and postexercise ischemia (PEI). BP and MSNA were measured during HG followed by PEI before and after a 23-min hypertonic saline infusion (HSI-3% NaCl). Eighteen participants (age 23 ± 1 yr; BMI 24 ± 1 kg/m²) completed the protocol; pOsm and sNa⁺ increased from pre- to post-HSI (285 ± 1 to 291 ± 1 mosmol/kg H₂O; 138.2 ± 0.3 to 141.3 ± 0.4 mM; P < 0.05 for both). Resting mean BP (90 ± 2 vs. 92 ± 1 mmHg) and MSNA (11 ± 2 vs. 15 ± 2 bursts/min) were increased pre- to post-HSI ( P < 0.05 for both). Mean BP responses to HG (106 ± 2 vs. 111 ± 2 mmHg, P < 0.05) and PEI (102 ± 2 vs. 107 ± 2 mmHg, P < 0.05) were higher post-HSI. Similarly, MSNA during HG (20 ± 2 vs. 29 ± 2 bursts/min, P < 0.05) and PEI (19 ± 2 vs. 24 ± 3 bursts/min, P < 0.05) were greater post-HSI. In addition, the change in MSNA was greater post-HSI during HG (Δ9 ± 2 vs. Δ13 ± 3 bursts/min, P < 0.05). A second set of participants ( n = 13, age 23 ± 1 yr; BMI 24 ± 1 kg/m²) completed a time control (TC) protocol consisting of quiet rest instead of an infusion. The TC condition yielded no change in resting sNa⁺, pOsm, mean BP, or MSNA (all P > 0.05); responses to HG and PEI were not different pre- to post-quiet rest ( P > 0.05). In summary, acutely increasing pOsm and sNa⁺ exaggerates BP and MSNA responses during HG exercise and PEI. NEW & NOTEWORTHY Elevated plasma osmolality has been shown to increase resting sympathetic activity and blood pressure. This study provides evidence that acute elevations in plasma osmolality and serum sodium exaggerated muscle sympathetic nerve activity and blood pressure responses during exercise pressor reflex activation in healthy young adults.