Effect of mannitol and hypertonic saline on cerebral oxygenation in patients with severe traumatic brain injury and refractory intracranial hypertension

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.

Comparing equiosmolar hypertonic saline and mannitol for achieving brain relaxation in elective craniotomy patients: A systematic review and meta-analysis

Background

This study strives to provide a current and thorough assessment of the comparative efficacy and safety between equiosmolar quantities of hypertonic saline (HS) and mannitol in facilitating brain relaxation for patients undergoing elective craniotomies.

Methods

This systematic review and meta-analysis, following preferred reporting items for systematic reviews and meta-analyses guidelines, compared the efficacy and safety of equiosmolar concentrations of mannitol and HS in elective craniotomies. PubMed, Scopus, Cochrane Library, ScienceDirect, and Proquest databases were searched using keywords related to mannitol, HS, and craniotomy. Results were analyzed through a random-effects model using Mantel-Haenszel risk ratio and standard mean difference. P < 0.05 was considered significant.

Results

Thirteen randomized controlled trials encompassing 965 patients (516 in the HS group and 448 in the mannitol group) were analyzed. The quality of studies was moderate-to-high, and no significant publication bias was observed. The primary outcome, brain relaxation, favored HS over mannitol without significant heterogeneity. Mannitol was associated with increased urine output compared to HS, irrespective of dose, with high heterogeneity. HS was linked to significantly reduced fluid input, confirmed by subgroup analysis with lower heterogeneity. No significant difference was found in serum osmolality between the two agents. Serum sodium (Na+) levels favored HS, whereas arterial blood Na+ levels also favored HS despite considerable heterogeneity. Maximum mean arterial pressure was higher with HS, but it displayed significant heterogeneity. Maximum central venous pressure showed no significant difference between the two agents, with moderate heterogeneity.

Conclusion

HS appears more effective than mannitol in achieving brain relaxation, and it may offer advantages in fluid management and Na+ balance. Clinicians should consider these findings when selecting hyperosmotic agents for neurosurgical procedures. Further research is needed to address heterogeneity in certain outcomes and guide clinical practice.

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.

Hypertonic Saline Compared to Mannitol for the Management of Elevated Intracranial Pressure in Traumatic Brain Injury: A Meta-Analysis

Background: We performed a meta-analysis to evaluate the effect of hypertonic saline compared to mannitol for the management of elevated intracranial pressure in traumatic brain injury.

Methods: A systematic literature search up to July 2021 was performed and 17 studies included 1,392 subjects with traumatic brain injury at the start of the study; 708 of them were administered hypertonic saline and 684 were given mannitol. They were reporting relationships between the effects of hypertonic saline compared to mannitol for the management of elevated intracranial pressure in traumatic brain injury. We calculated the odds ratio (OR) and mean difference (MD) with 95% confidence intervals (CIs) to assess the effect of hypertonic saline compared to mannitol for the management of elevated intracranial pressure in traumatic brain injury using the dichotomous or continuous method with a random or fixed-effect model.

Results: Hypertonic saline had significantly lower treatment failure (OR, 0.38; 95% CI, 0.15–0.98, p = 0.04), lower intracranial pressure 30–60 mins after infusion termination (MD, −1.12; 95% CI, −2.11 to −0.12, p = 0.03), and higher cerebral perfusion pressure 30–60 mins after infusion termination (MD, 5.25; 95% CI, 3.59–6.91, p &lt; 0.001) compared to mannitol in subjects with traumatic brain injury.

However, hypertonic saline had no significant effect on favorable outcome (OR, 1.61; 95% CI, 1.01–2.58, p = 0.05), mortality (OR, 0.59; 95% CI, 0.34–1.02, p = 0.06), intracranial pressure 90–120 mins after infusion termination (MD, −0.90; 95% CI, −3.21–1.41, p = 0.45), cerebral perfusion pressure 90–120 mins after infusion termination (MD, 4.28; 95% CI, −0.16–8.72, p = 0.06), and duration of elevated intracranial pressure per day (MD, 2.20; 95% CI, −5.44–1.05, p = 0.18) compared to mannitol in subjects with traumatic brain injury.

Conclusions: Hypertonic saline had significantly lower treatment failure, lower intracranial pressure 30–60 mins after infusion termination, and higher cerebral perfusion pressure 30–60 mins after infusion termination compared to mannitol in subjects with traumatic brain injury. However, hypertonic saline had no significant effect on the favorable outcome, mortality, intracranial pressure 90–120 mins after infusion termination, cerebral perfusion pressure 90–120 mins after infusion termination, and duration of elevated intracranial pressure per day compared to mannitol in subjects with traumatic brain injury. Further studies are required to validate these findings.

Comparison of half-molar sodium lactate and mannitol to treat brain edema in severe traumatic brain injury: A systematic review

PURPOSE

Hypertonic fluids such as mannitol and half-molar sodium lactate are given to treat intracranial hypertension in patients with severe traumatic brain injury (TBI). In this study, sodium lactate was compared to mannitol in patients with TBI to investigate the efficacy in reducing intracranial pressure (ICP).

METHODS

This study was a systematic review with literature research on articles published in any year in the databases of PubMed, ScienceDirect, Asian Journal of Neurosurgery, and Cochrane Central Register of Controlled Trials. The keywords were "half-molar sodium lactate", "mannitol", "cerebral edema or brain swelling", and "severe traumatic brain injury". The inclusion criteria were (1) studies published in English, (2) randomized control trials or retrospective/prospective studies on TBI patients, and (3) therapies including half-molar sodium lactate and mannitol and (4) sufficient data such as mean difference (MD) and risk ratio (RR). Data analysis was conducted using Review Manager 5.3.

RESULTS

From 1499 studies, a total of 8 studies were eligible. Mannitol group reduced ICP of 0.65 times (MD 0.65; p = 0.64) and improved cerebral perfusion pressure of 0.61 times (MD 0.61; p = 0.88), better than the half-molar group of sodium lactate. But the half-molar group of sodium lactate maintained the mean arterial pressure level of 0.86 times, better than the mannitol group (MD 0.86; p = 0.09).

CONCLUSION

Half-molar sodium lactate is as effective as mannitol in reducing ICP in the early phase of brain injury, superior over mannitol in an extended period. It is able to prevent intracranial hypertension and give better brain tissue perfusion as well as more stable hemodynamics. Blood osmolarity is a concern as it increases serum sodium.

Moderate and Severe Traumatic Brain Injury

PURPOSE OF REVIEW

Traumatic brain injury (TBI) encompasses a group of heterogeneous manifestations of a disease process with high neurologic morbidity and, for severe TBI, high probability of mortality and poor neurologic outcomes. This article reviews TBI in neurocritical care, hence focusing on moderate and severe TBI, and includes an up-to-date review of the many variables to be considered in clinical care.

RECENT FINDINGS

With advances in medicine and biotechnology, understanding of the impact of TBI has substantially elucidated the distinction between primary and secondary brain injury. Consequently, care of TBI is evolving, with intervention-based modalities targeting multiple physiologic variables. Multimodality monitoring to assess intracranial pressure, cerebral oxygenation, cerebral metabolism, cerebral blood flow, and autoregulation is at the forefront of such advances.

SUMMARY

Understanding the anatomic and physiologic principles of acute brain injury is necessary in managing moderate to severe TBI. Management is based on the prevention of secondary brain injury from resultant trauma. Care of patients with TBI should occur in a dedicated critical care unit with subspecialty expertise. With the advent of multimodality monitoring and targeted biomarkers in TBI, patient outcomes have a higher probability of improving in the future.

Evidence for Mannitol as an Effective Agent Against Intracranial Hypertension: An Individual Patient Data Meta-analysis

Mannitol is currently used to reduce intracranial pressure (ICP), but the evidence supporting its usefulness has been questioned. We aim to meta-analyze the effectiveness of mannitol in reducing ICP in adult patients with cerebral injuries and its dependency on baseline ICP values, comparing findings from individual patient data (IPD) and aggregated data (AD) meta-analysis performed on the same studies. We searched the Medline database, with no time limitation, through March 1, 2019. We selected studies for which IPD were available, with a before-after design, concerning adult patients with traumatic cerebral hemorrhages, subarachnoid hemorrhages, or hemorrhagic and ischemic stroke, treated with mannitol for increased intracranial hypertension. We extracted ICP values at baseline and at different time-points, and mannitol doses. We used a multilevel approach to account for multiple measurements on the same patient and for center variability. The AD meta-analysis and meta-regression were conducted using random-effects models. Three studies published IPD, and four authors shared their datasets. Two authors did not own their datasets anymore. Eight authors were unreachable, while 14 did not answer to our request. Overall, 7 studies provided IPD for 98 patients. The linear mixed-effects model showed that ICP decreased significantly after mannitol administration from an average baseline value of 22.1 mmHg to 16.8, 12.8, and 9.7 mmHg at 60, 120, and 180 min after mannitol administration. ICP reduction was proportional to baseline values with a 0.64 mmHg decrease for each unitary increment of the initial ICP value. Dose did not influence ICP reduction. The AD meta-analysis, based on data collected between 30 and 60 min from mannitol administration not accounting for multiple time-point measurements, overestimated ICP reduction (10 mmHg), while meta-regression provided similar results (0.66 mmHg decrease for each unitary increase of initial ICP). Mannitol is effective in reducing pathological ICP, proportionally to the degree of intracranial hypertension. IPD meta-analysis provided a more precise quantification of ICP variation than the AD approach.

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.

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.

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.

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.

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 mannitol plus hypertonic saline combination versus hypertonic saline monotherapy on acute kidney injury after traumatic brain injury

PURPOSE

To compare the effect of mannitol plus hypertonic saline combination (MHS) versus hypertonic saline monotherapy (HS) on renal function in patients with traumatic brain injury (TBI).

MATERIALS AND METHODS

This was a secondary analysis of data from the Resuscitation Outcomes Consortium Hypertonic Saline Trial Shock Study and Traumatic Brain Injury Study. The study cohort included a propensity matched subset of patients with TBI who received MHS or HS. The primary outcome measure was the maximum serum creatinine value during critical illness.

RESULTS

The cohort consisted of 163 patients in the MHS group and 163 patients in the HS group (n = 326). The maximum serum creatinine value during hospitalization was 82 ± 47 μmol/L (0.86 ± 0.26 mg/dL) in the MHS group and 76 ± 23 μmol/L (0.92 ± 0.53 mg/dL) in the HS group (difference -6 μmol/L, 95% CI -14 to 2 μmol/L, p = .151). The lowest eGFR during hospitalization was 108 ± 25 mL/min in the MHS group and 112 ± 24 mL/min in the HS group (difference -4 mL/min, 95% CI -1 to 9 mLmin, p = .150).

CONCLUSIONS

The addition of mannitol to HS did not increase the risk of renal dysfunction compared to HS alone in patients with TBI.

Cerebral Edema in Traumatic Brain Injury: a Historical Framework for Current Therapy

PURPOSE OF REVIEW

The purposes of this narrative review are to (1) summarize a contemporary view of cerebral edema pathophysiology, (2) present a synopsis of current management strategies in the context of their historical roots (many of which date back multiple centuries), and (3) discuss contributions of key molecular pathways to overlapping edema endophenotypes. This may facilitate identification of important therapeutic targets.

RECENT FINDINGS

Cerebral edema and resultant intracranial hypertension are major contributors to morbidity and mortality following traumatic brain injury. Although Starling forces are physical drivers of edema based on differences in intravascular vs extracellular hydrostatic and oncotic pressures, the molecular pathophysiology underlying cerebral edema is complex and remains incompletely understood. Current management protocols are guided by intracranial pressure measurements, an imperfect proxy for cerebral edema. These include decompressive craniectomy, external ventricular drainage, hyperosmolar therapy, hypothermia, and sedation. Results of contemporary clinical trials assessing these treatments are summarized, with an emphasis on the gap between intermediate measures of edema and meaningful clinical outcomes. This is followed by a brief statement summarizing the most recent guidelines from the Brain Trauma Foundation (4th edition). While many molecular mechanisms and networks contributing to cerebral edema after TBI are still being elucidated, we highlight some promising molecular mechanism-based targets based on recent research including SUR1-TRPM4, NKCC1, AQP4, and AVP1.

SUMMARY

This review outlines the origins of our understanding of cerebral edema, chronicles the history behind many current treatment approaches, and discusses promising molecular mechanism-based targeted treatments.

Hypertonic saline versus other intracranial pressure-lowering agents for people with acute traumatic brain injury

BACKGROUND

Increased intracranial pressure has been shown to be strongly associated with poor neurological outcomes and mortality for patients with acute traumatic brain injury. Currently, most efforts to treat these injuries focus on controlling the intracranial pressure. Hypertonic saline is a hyperosmolar therapy that is used in traumatic brain injury to reduce intracranial pressure. The effectiveness of hypertonic saline compared with other intracranial pressure-lowering agents in the management of acute traumatic brain injury is still debated, both in the short and the long term.

OBJECTIVES

To assess the comparative efficacy and safety of hypertonic saline versus other intracranial pressure-lowering agents in the management of acute traumatic brain injury.

SEARCH METHODS

We searched Cochrane Injuries' Specialised Register, CENTRAL, PubMed, Embase Classic+Embase, ISI Web of Science: Science Citation Index and Conference Proceedings Citation Index-Science, as well as trials registers, on 11 December 2019. We supplemented these searches with searches of four major Chinese databases on 19 September 2018. We also checked bibliographies, and contacted trial authors to identify additional trials.

SELECTION CRITERIA

We sought to identify all randomised controlled trials (RCTs) of hypertonic saline versus other intracranial pressure-lowering agents for people with acute traumatic brain injury of any severity. We excluded cross-over trials as incompatible with assessing long-term outcomes.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened search results to identify potentially eligible trials and extracted data using a standard data extraction form. Outcome measures included: mortality at end of follow-up (all-cause); death or disability (as measured by the Glasgow Outcome Scale (GOS)); uncontrolled intracranial pressure (defined as failure to decrease the intracranial pressure to target and/or requiring additional intervention); and adverse events e.g. rebound phenomena; pulmonary oedema; acute renal failure during treatment).

MAIN RESULTS

Six trials, involving data from 287 people, met the inclusion criteria. The majority of participants (91%) had a diagnosis of severe traumatic brain injury. We had concerns about particular domains of risk of bias in each trial, as physicians were not reliably blinded to allocation, two trials contained participants with conditions other than traumatic brain injury and in one trial, we had concerns about missing data for important outcomes. The original protocol was available for only one trial and other trials (where registered) were registered retrospectively. Meta-analysis for both the primary outcome (mortality at final follow-up) and for 'poor outcome' as per conventionally dichotomised GOS criteria, was only possible for two trials. Synthesis of long-term outcomes was inhibited by the fact that two trials ceased data collection within two hours of a single bolus dose of an intracranial pressure-lowering agent and one at discharge from the intensive care unit (ICU). Only three trials collected data after participants were released from hospital, one of which did not report mortality and reported a 'poor outcome' by GOS criteria in an unconventional way. Substantial missing data in a key trial meant that in meta-analysis we report 'best-case' and 'worst-case' estimates alongside available case analysis. In no scenario did we discern a clear difference between treatments for either mortality or poor neurological outcome. Due to variation in modes of drug administration (including whether it followed or did not follow cerebrospinal fluid (CSF) drainage, as well as different follow-up times and ways of reporting changes in intracranial pressure, as well as no uniform definition of 'uncontrolled intracranial pressure', we did not perform meta-analysis for this outcome and report results narratively, by individual trial. Trials tended to report both treatments to be effective in reducing elevated intracranial pressure but that hypertonic saline had increased benefits, usually adding that pretreatment factors need to be considered (e.g. serum sodium and both system and brain haemodynamics). No trial provided data for our other outcomes of interest. We consider evidence quality for all outcomes to be very low, as assessed by GRADE; we downgraded all conclusions due to imprecision (small sample size), indirectness (due to choice of measurement and/or selection of participants without traumatic brain injury), and in some cases, risk of bias and inconsistency. Only one of the included trials reported data on adverse effects; a rebound phenomenon, which was present only in the comparator group (mannitol). None of the trials reported data on pulmonary oedema or acute renal failure during treatment. On the whole, trial authors do not seem to have rigorously sought to collect data on adverse events.

AUTHORS' CONCLUSIONS

This review set out to find trials comparing hypertonic saline to a potential range of other intracranial pressure-lowering agents, but only identified trials comparing it with mannitol or mannitol in combination with glycerol. Based on limited data, there is weak evidence to suggest that hypertonic saline is no better than mannitol in efficacy and safety in the long-term management of acute traumatic brain injury. Future research should be comprised of large, multi-site trials, prospectively registered, reported in accordance with current best practice. Trials should investigate issues such as the type of traumatic brain injury suffered by participants and concentration of infusion and length of time over which the infusion is given.

Hypertonic saline versus other intracranial pressure-lowering agents for people with acute traumatic brain injury

BACKGROUND

Increased intracranial pressure (ICP) has been shown to be strongly associated with poor neurological outcomes and mortality for patients with acute traumatic brain injury (TBI). Currently, most efforts to treat these injuries focus on controlling the ICP. Hypertonic saline (HTS) is a hyperosmolar therapy that is used in traumatic brain injury to reduce intracranial pressure. The effectiveness of HTS compared with other ICP-lowering agents in the management of acute TBI is still debated, both in the short and the long term.

OBJECTIVES

To assess the comparative efficacy and safety of hypertonic saline versus other ICP-lowering agents in the management of acute TBI.

SEARCH METHODS

We searched the Cochrane Injuries Group's Specialised Register, The Cochrane Library, PubMed, Embase Classic+Embase (OvidSP), ISI Web of Science: Science Citation Index and Conference Proceedings Citation Index-Science, as well as trials registers, on 11 December 2019. We supplemented these searches using four major Chinese databases on 19 September 2018. We also checked bibliographies, and contacted study authors to identify additional studies.

SELECTION CRITERIA

We sought to identify all randomised controlled trials (RCTs) of HTS versus other intracranial pressure-lowering agents for people with acute TBI of any severity. We excluded cross-over trials as incompatible with assessing long term outcomes.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened search results to identify potentially eligible trials and extracted data using a standard data extraction form. Outcome measures included: mortality at end of follow-up (all-cause); death or disability (as measured by the Glasgow Outcome Scale (GOS)); uncontrolled ICP (defined as failure to decrease the ICP to target and/or requiring additional intervention); and adverse events (AEs) (e.g. rebound phenomena; pulmonary oedema; acute renal failure during treatment).

MAIN RESULTS

Six trials, involving data from 295 people, met the inclusion criteria. The majority of participants (89%) had a diagnosis of severe TBI. We had concerns about particular domains of risk of bias in each trial, as physicians were not reliably blinded to allocation, two trials contained participants with conditions other than TBI and in one trial, there were concerns about missing data for important outcomes. The original protocol was available for only one study and other trials (where registered) were registered retrospectively. Meta-analysis for both the primary outcome (mortality at final follow up) and for 'poor outcome' as per conventionally dichotomised GOS criteria, was only possible for two studies. Synthesis of long-term outcomes was inhibited by the fact that two ceased data collection within two hours of a single bolus dose of an ICP-lowering agent and one at discharge from ICU. Only three studies collected data after release from hospital. Due to variation in modes of drug administration, follow-up times, and ways of reporting changes in ICP, as well as no uniform definition of 'uncontrolled ICP', we did not perform meta-analysis for this outcome and report results narratively, by individual trial. Trials tended to report both treatments to be effective in reducing elevated ICP but that HTS had increased benefits, usually adding that pretreatment factors need to be considered (e.g. serum sodium and both system and brain hemodynamics). No trial provided data for our other outcomes of interest. Evidence for all outcomes is considered very low, as assessed by GRADE. All conclusions were downgraded due to imprecision (small sample size), indirectness (due to choice of measurement and/or selection of patients without TBI), and in some cases, risk of bias and inconsistency. Only one of the included trials reported data on adverse effects (AEs) - a rebound phenomenon, which was present only in the comparator group (mannitol). No data were reported on pulmonary oedema or acute renal failure during treatment. On the whole, investigators do not seem to have rigorously sought to collect data on AEs.

AUTHORS' CONCLUSIONS

This review set out to find trials comparing HTS to a potential range of other ICP-lowering agents, but only identified trials comparing it with mannitol or mannitol in combination with glycerol. Based on limited data, there is weak evidence to suggest that HTS is no better than mannitol in efficacy and safety in the long-term management of acute TBI. Future research should be comprised of large, multi-site trials, prospectively registered, reported in accordance with current best practice. Issues such as the type of TBI suffered by participants and concentration of infusion and length of time over which the infusion is given should be investigated.

Hypertonic Lactate to Improve Cerebral Perfusion and Glucose Availability After Acute Brain Injury

OBJECTIVES

Lactate promotes cerebral blood flow and is an efficient substrate for the brain, particularly at times of glucose shortage. Hypertonic lactate is neuroprotective after experimental brain injury; however, human data are limited.

DESIGN

Prospective study (clinicaltrials.gov NCT01573507).

SETTING

Academic ICU.

PATIENTS

Twenty-three brain-injured subjects (13 traumatic brain injury/10 subarachnoid hemorrhage; median age, 59 yr [41-65 yr]; median Glasgow Coma Scale, 6 [3-7]).

INTERVENTIONS

Three-hour IV infusion of hypertonic lactate (sodium lactate, 1,000 mmol/L; concentration, 30 µmol/kg/min) administered 39 hours (26-49 hr) from injury.

MEASUREMENTS AND MAIN RESULTS

We examined the effect of hypertonic lactate on cerebral perfusion (using transcranial Doppler) and brain energy metabolism (using cerebral microdialysis). The majority of subjects (13/23 = 57%) had reduced brain glucose availability (baseline pretreatment cerebral microdialysis glucose, < 1 mmol/L) despite normal baseline intracranial pressure (10 [7-15] mm Hg). Hypertonic lactate was associated with increased cerebral microdialysis lactate (+55% [31-80%]) that was paralleled by an increase in middle cerebral artery mean cerebral blood flow velocities (+36% [21-66%]) and a decrease in pulsatility index (-21% [13-26%]; all p < 0.001). Cerebral microdialysis glucose increased above normal range during hypertonic lactate (+42% [30-78%]; p < 0.05); reduced brain glucose availability correlated with a greater improvement of cerebral microdialysis glucose (Spearman r = -0.53; p = 0.009). No significant changes in cerebral perfusion pressure, mean arterial pressure, systemic carbon dioxide, and blood glucose were observed during hypertonic lactate (all p > 0.1).

CONCLUSIONS

This is the first clinical demonstration that hypertonic lactate resuscitation improves both cerebral perfusion and brain glucose availability after brain injury. These cerebral vascular and metabolic effects appeared related to brain lactate supplementation rather than to systemic effects.

Cerebral influx of Na+ and Cl- as the osmotherapy-mediated rebound response in rats

Background

Cerebral edema can cause life-threatening increase in intracranial pressure. Besides surgical craniectomy performed in severe cases, osmotherapy may be employed to lower the intracranial pressure by osmotic extraction of cerebral fluid upon intravenous infusion of mannitol or NaCl. A so-called rebound effect can, however, hinder continuous reduction in cerebral fluid by yet unresolved mechanisms.

Methods

We determined the brain water and electrolyte content in healthy rats treated with osmotherapy. Osmotherapy (elevated plasma osmolarity) was mediated by intraperitoneal injection of NaCl or mannitol with inclusion of pharmacological inhibitors of selected ion-transporters present at the capillary lumen or choroidal membranes. Brain barrier integrity was determined by fluorescence detection following intravenous delivery of Na⁺-fluorescein.

Results

NaCl was slightly more efficient than mannitol as an osmotic agent. The brain water loss was only ~ 60% of that predicted from ideal osmotic behavior, which could be accounted for by cerebral Na⁺ and Cl⁻ accumulation. This electrolyte accumulation represented the majority of the rebound response, which was unaffected by the employed pharmacological agents. The brain barriers remained intact during the elevated plasma osmolarity.

Conclusions

A brain volume regulatory response occurs during osmotherapy, leading to the rebound response. This response involves brain accumulation of Na⁺ and Cl⁻ and takes place by unresolved molecular mechanisms that do not include the common ion-transporting mechanisms located in the capillary endothelium at the blood–brain barrier and in the choroid plexus epithelium at the blood–CSF barrier. Future identification of these ion-transporting routes could provide a pharmacological target to prevent the rebound effect associated with the widely used osmotherapy.

Effects of Hypertonic Saline and Sodium Lactate on Cortical Cerebral Microcirculation and Brain Tissue Oxygenation

BACKGROUND

Hyperosmolar solutions have been used in neurosurgery to modify brain bulk. The aim of this animal study was to compare the short-term effects of equivolemic, equiosmolar solutions of hypertonic saline (HTS) and sodium lactate (HTL) on cerebral cortical microcirculation and brain tissue oxygenation in a rabbit craniotomy model.

METHODS

Rabbits (weight, 1.5 to 2.0 kg) were anesthetized, ventilated mechanically, and subjected to a craniotomy. The animals were allocated randomly to receive a 3.75 mL/kg intravenous infusion of either 3.2% HTS (group HTS, n=9), half-molar sodium lactate (group HTL, n=10), or normal saline (group C, n=9). Brain tissue partial pressure of oxygen (PbtO2) and microcirculation in the cerebral cortex using sidestream dark-field imaging were evaluated before, 20 and 40 minutes after 15 minutes of hyperosmolar solution infusion. Global hemodynamic data were recorded, and blood samples for laboratory analysis were obtained at the time of sidestream dark-field image recording.

RESULTS

No differences in the microcirculatory parameters were observed between the groups before and after the use of osmotherapy. Brain tissue oxygen deteriorated over time in groups C and HTL, this deterioration was not significant in the group HTS.

CONCLUSIONS

Our findings suggest that equivolemic, equiosmolar HTS and HTL solutions equally preserve perfusion of cortical brain microcirculation in a rabbit craniotomy model. The use of HTS was better in preventing the worsening of brain tissue oxygen tension.

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.

Treatment of Tuberculous Meningitis and Its Complications in Adults

PURPOSE OF REVIEW

Tuberculous meningitis (TBM) is a global health problem. In this review, we systematically evaluate the evidence for current and emerging antimicrobials, host-directed therapies and supportive managements.

RECENT FINDINGS

Current antimicrobial regimes do not factor the differing ability of drugs to cross the blood-brain barrier. Rifampicin may be more effective at higher doses yet the most recent clinical trial failed to demonstrate survival benefit at 15 mg/kg/day. Dose finding studies suggest that higher doses still may be safe and more effective. Fluoroquinolones are currently listed as important second-line agents in drug-resistant TBM; however, a survival benefit as a first-line agent has yet to be shown. Linezolid may be a promising antimicrobial with good central nervous system penetrance. Dexamethasone reduces mortality in HIV-uninfected individuals yet evidence for its use in HIV co-infection is lacking. Aspirin has anti-inflammatory and anti-thrombotic properties. Small studies have demonstrated efficacy in reducing stroke but further research is required to better understand its effect on controlling the host inflammatory response. Discovery of genetic polymorphisms may direct individualized immune therapies and mediators of the innate immune response may provide targets for the development of novel therapies. There is at present no significant evidence base to guide management of hydrocephalus in HIV co-infection. Further clinical trial data is required to improve treatment outcomes in TBM in particularly in regard to the value of high-dose rifampicin, newer antimicrobials with improved central nervous system penetration and host-directed therapies. Supportive measures in particular the management of hydrocephalus in HIV co-infection should be an area for future research.

Cardiac output changes after osmotic therapy in neurosurgical and neurocritical care patients: a systematic review of the clinical literature

AIM

Osmotherapy constitutes a first-line intervention for intracranial hypertension management. However, hyperosmolar solutes exert various systematic effects, among which their impact on systemic haemodynamics is poorly clarified. This review aims to appraise the clinical evidence of the effect of mannitol and hypertonic saline (HTS) on cardiac performance in neurosurgical and neurocritical care patients.

METHOD

A database search was conducted to identify randomized clinical trials and observational studies reporting HTS or mannitol use in acute brain injury setting. The primary end-points were alterations of cardiac output (CO) and other haemodynamic variables, while the impact of osmotic agents on intracranial pressure, brain relaxation, plasma osmolality, electrolyte levels and urinary output constituted secondary outcomes.

RESULTS

Eight studies, enrolling 182 patients in total, were included. HTS exerted a more profound cardiac output augmentation than mannitol, but no distinct difference between groups occurred. Central venous pressure, stroke volume and stroke volume variation were favourably affected by both osmotic agents, whilst the reported changes in blood pressure were inconclusive. HTS infusion yielded a larger intracranial pressure reduction than mannitol but had an equivalent effect on brain relaxation. Mannitol presented a more potent diuretic effect than HTS. Effect on serum osmolality was alike in both osmotic agents, but contrary to HTS-promoted hypernatraemia, mannitol use induced transient hyponatraemia.

CONCLUSIONS

Mannitol or HTS administration seems to induce an enhancement of cardiac performance; being more prominent after HTS infusion. This effect combined with mannitol-induced enhancement of diuresis and HTS-promoted increase of plasma sodium concentration could partially explain the effects of osmotherapy on cerebral haemodynamics.

Tuberculous meningitis

Tuberculosis remains a global health problem, with an estimated 10.4 million cases and 1.8 million deaths resulting from the disease in 2015. The most lethal and disabling form of tuberculosis is tuberculous meningitis (TBM), for which more than 100,000 new cases are estimated to occur per year. In patients who are co-infected with HIV-1, TBM has a mortality approaching 50%. Study of TBM pathogenesis is hampered by a lack of experimental models that recapitulate all the features of the human disease. Diagnosis of TBM is often delayed by the insensitive and lengthy culture technique required for disease confirmation. Antibiotic regimens for TBM are based on those used to treat pulmonary tuberculosis, which probably results in suboptimal drug levels in the cerebrospinal fluid, owing to poor blood-brain barrier penetrance. The role of adjunctive anti-inflammatory, host-directed therapies - including corticosteroids, aspirin and thalidomide - has not been extensively explored. To address this deficit, two expert meetings were held in 2009 and 2015 to share findings and define research priorities. This Review summarizes historical and current research into TBM and identifies important gaps in our knowledge. We will discuss advances in the understanding of inflammation in TBM and its potential modulation; vascular and hypoxia-mediated tissue injury; the role of intensified antibiotic treatment; and the importance of rapid and accurate diagnostics and supportive care in TBM.

A Comparison of Pharmacologic Therapeutic Agents Used for the Reduction of Intracranial Pressure After Traumatic Brain Injury

OBJECTIVE

In neurotrauma care, a better understanding of treatments after traumatic brain injury (TBI) has led to a significant decrease in morbidity and mortality in this population. TBI represents a significant medical problem, and complications after TBI are associated with the initial injury and postevent intracranial processes such as increased intracranial pressure and brain edema. Consequently, appropriate therapeutic interventions are required to reduce brain tissue damage and improve cerebral perfusion. We present a contemporary review of literature on the use of pharmacologic therapies to reduce intracranial pressure after TBI and a comparison of their efficacy.

METHODS

This review was conducted by PubMed query. Only studies discussing pharmacologic management of patients after TBI were included. This review includes prospective and retrospective studies and includes randomized controlled trials as well as cohort, case-control, observational, and database studies. Systematic literature reviews, meta-analyses, and studies that considered conditions other than TBI or pediatric populations were not included.

RESULTS

Review of the literature describing the current pharmacologic treatment for intracranial hypertension after TBI most often discussed the use of hyperosmolar agents such as hypertonic saline and mannitol, sedatives such as fentanyl and propofol, benzodiazepines, and barbiturates. Hypertonic saline is associated with faster resolution of intracranial hypertension and restoration of optimal cerebral hemodynamics, although these advantages did not translate into long-term benefits in morbidity or mortality. In patients refractory to treatment with hyperosmolar therapy, induction of a barbiturate coma can reduce intracranial pressure, although requires close monitoring to prevent adverse events.

CONCLUSIONS

Current research suggests that the use of hypertonic saline after TBI is the best option for immediate decrease in intracranial pressure. A better understanding of the efficacy of each treatment option can help to direct treatment algorithms during the critical early hours of trauma care and continue to improve morbidity and mortality after TBI.

Comparison of 20% mannitol and 3% hypertonic saline on intracranial pressure and systemic hemodynamics

Mannitol and hypertonic saline (HS) are most commonly used hyperosmotic agents for intraoperative brain relaxation. We compared the changes in ICP and systemic hemodynamics after infusion of equiosmolar solutions of both agents in patients undergoing craniotomy for supratentorial tumors. Forty enrolled adults underwent a standard anesthetic induction. Apart from routine monitoring parameters, subdural ICP with Codmann catheter and cardiac indices by Vigileo monitor, were recorded. The patients were randomized to receive equiosmolar solutions of either 20% mannitol (5ml/kg) or 3% HS (5.35ml/kg) for brain relaxation. The time of placement of ICP catheter was marked as T₀ and baseline ICP and systemic hemodynamic variables were noted; it was followed by recording of the same parameters every 5min till 45min (Study Period). After the completion of study period, brain relaxation score as assessed by the neurosurgeon was recorded. Arterial blood gas (ABG) was analysed every 30min starting from T₀ upto one and half hours (T₉₀), and values of various parameters were recorded. Data was analysed using appropriate statistical methods. Both mannitol and HS significantly reduced the ICP; the values were comparable in between the two groups at most of the times. The brain relaxation score was comparable in both the groups. Urine output was significantly higher with mannitol. The perioperative complications, overall hospital stay, and Glasgow outcome score at discharge were comparable in between the two groups. To conclude, both mannitol and hypertonic saline in equiosmolar concentrations produced comparable effects on ICP reduction, brain relaxation, and systemic hemodynamics.

Effectiveness of 7.5% hypertonic saline in children with severe traumatic brain injury

PURPOSE

Hyperosmolar therapies aim at controlling increased intracranial pressure (ICP) in patients with traumatic brain injury (TBI). The aim of this study was to evaluate the effect of 7.5% hypertonic saline (HTS) on ICP and cerebral perfusion pressure (CPP) in children with severe TBI.

MATERIALS AND METHODS

Medical records of patients 14 years or younger with severe TBI, admitted in the pediatric intensive care unit of "Aghia Sophia" Children's Hospital, Athens, Greece, during 2009 to 2015, and received HTS apart from mannitol were retrospectively reviewed. The ICP and CPP pre-HTS and 30, 60, and 120 minutes post-HTS infusion were evaluated. Furthermore, the presence of adverse effects, the long-term neurological outcome, and survival were recorded.

RESULTS

Twenty-nine patients requiring in total 136 HTS infusions were analyzed. The ICP was significantly reduced and CPP elevated at 30, 60, and 120 minutes postinfusion; and furthermore, postadministration ICP and CPP were predominantly within acceptable limits. No significant adverse effects were recorded and most of the patients survived, however, one third had severe neurological impairment at 6 months postinjury.

CONCLUSIONS

In our study, 7.5% HTS infusion as a second-tier osmotic therapy was associated with significant reduction of ICP and increase of CPP in children with severe TBI.

Evaluating the Role of Reduced Oxygen Saturation and Vascular Damage in Traumatic Brain Injury Using Magnetic Resonance Perfusion-Weighted Imaging and Susceptibility-Weighted Imaging and Mapping

The cerebral vasculature, along with neurons and axons, is vulnerable to biomechanical insult during traumatic brain injury (TBI). Trauma-induced vascular injury is still an underinvestigated area in TBI research. Cerebral blood flow and metabolism could be important future treatment targets in neural critical care. Magnetic resonance imaging offers a number of key methods to probe vascular injury and its relationship with traumatic hemorrhage, perfusion deficits, venous blood oxygen saturation changes, and resultant tissue damage. They make it possible to image the hemodynamics of the brain, monitor regional damage, and potentially show changes induced in the brain's function not only acutely but also longitudinally following treatment. These methods have recently been used to show that even mild TBI (mTBI) subjects can have vascular abnormalities, and thus they provide a major step forward in better diagnosing mTBI patients.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Mannitol Improves Brain Tissue Oxygenation in a Model of Diffuse Traumatic Brain Injury

OBJECTIVES

Based on evidence supporting a potential relation between posttraumatic brain hypoxia and microcirculatory derangements with cell edema, we investigated the effects of the antiedematous agent mannitol on brain tissue oxygenation in a model of diffuse traumatic brain injury.

DESIGN

Experimental study.

SETTING

Neurosciences and physiology laboratories.

SUBJECTS

Adult male Wistar rats.

INTERVENTIONS

Thirty minutes after diffuse traumatic brain injury (impact-acceleration model), rats were IV administered with either a saline solution (traumatic brain injury-saline group) or 20% mannitol (1 g/kg) (traumatic brain injury-mannitol group). Sham-saline and sham-mannitol groups received no insult.

MEASUREMENTS AND MAIN RESULTS

Two series of experiments were conducted 2 hours after traumatic brain injury (or equivalent) to investigate 1) the effect of mannitol on brain edema and oxygenation, using a multiparametric magnetic resonance-based approach (n = 10 rats per group) to measure the apparent diffusion coefficient, tissue oxygen saturation, mean transit time, and blood volume fraction in the cortex and caudoputamen; 2) the effect of mannitol on brain tissue PO2 and on venous oxygen saturation of the superior sagittal sinus (n = 5 rats per group); and 3) the cortical ultrastructural changes after treatment (n = 1 per group, taken from the first experiment). Compared with the sham-saline group, the traumatic brain injury-saline group had significantly lower tissue oxygen saturation, brain tissue PO2, and venous oxygen saturation of the superior sagittal sinus values concomitant with diffuse brain edema. These effects were associated with microcirculatory collapse due to astrocyte swelling. Treatment with mannitol after traumatic brain injury reversed all these effects. In the absence of traumatic brain injury, mannitol had no effect on brain oxygenation. Mean transit time and blood volume fraction were comparable between the four groups of rats.

CONCLUSION

The development of posttraumatic brain edema can limit the oxygen utilization by brain tissue without evidence of brain ischemia. Our findings indicate that an antiedematous agent such as mannitol can improve brain tissue oxygenation, possibly by limiting astrocyte swelling and restoring capillary perfusion.

Mannitol or hypertonic saline in the setting of traumatic brain injury: What have we learned?

Background:

Intracranial hypertension, defined as an intracranial pressure (ICP) >20 mmHg for a period of more than 5 min, worsens neurologic outcome in traumatic brain injury (TBI). While several mechanisms contribute to poor outcome, impaired cerebral perfusion appears to be a highly significant common denominator. Management guidelines from the Brain Trauma Foundation recommend measuring ICP to guide therapy. In particular, hyperosmolar therapy, which includes mannitol or hypertonic saline (HTS), is frequently administered to reduce ICP. Currently, mannitol (20%) is considered the gold standard hyperosmolar agent. However, HTS is increasingly used in this setting. This review sought to compare the efficacy of mannitol to HTS in severe TBI.

Methods:

The PubMed database was used to systematically search for articles comparing mannitol to HTS in severe TBI. The following medical subject headings were used: HTS, sodium lactate, mannitol, ICP, intracranial hypertension, and TBI. We included both prospective and retrospective randomized controlled studies of adult patients with intracranial hypertension as a result of severe TBI who received hyperosmolar therapy.

Results:

Out of 45 articles, seven articles were included in our review: 5 were prospective, randomized trials; one was a prospective, nonrandomized trial; and one was a retrospective, cohort study.

Conclusions:

While all seven studies found that both mannitol and HTS were effective in reducing ICP, there was heterogeneity with regard to which agent was most efficacious.

Monitoring of brain and systemic oxygenation in neurocritical care patients

Maintenance of adequate oxygenation is a mainstay of intensive care, however, recommendations on the safety, accuracy, and the potential clinical utility of invasive and non-invasive tools to monitor brain and systemic oxygenation in neurocritical care are lacking. A literature search was conducted for English language articles describing bedside brain and systemic oxygen monitoring in neurocritical care patients from 1980 to August 2013. Imaging techniques e.g., PET are not considered. A total of 281 studies were included, the majority described patients with traumatic brain injury (TBI). All tools for oxygen monitoring are safe. Parenchymal brain oxygen (PbtO2) monitoring is accurate to detect brain hypoxia, and it is recommended to titrate individual targets of cerebral perfusion pressure (CPP), ventilator parameters (PaCO2, PaO2), and transfusion, and to manage intracranial hypertension, in combination with ICP monitoring. SjvO2 is less accurate than PbtO2. Given limited data, NIRS is not recommended at present for adult patients who require neurocritical care. Systemic monitoring of oxygen (PaO2, SaO2, SpO2) and CO2 (PaCO2, end-tidal CO2) is recommended in patients who require neurocritical care.

Effects of hypertonic saline and mannitol on cortical cerebral microcirculation in a rabbit craniotomy model

Background

Hyperosmolar solutions have been used in neurosurgery to modify brain bulk and prevent neurological deterioration. The aim of this animal study was to compare the short-term effects of equivolemic, equiosmolar solutions of mannitol and hypertonic saline (HTS) on cerebral cortical microcirculation in a rabbit craniotomy model.

Methods

Rabbits (weight, 2.0–3.0 kg) were anesthetized, ventilated mechanically, and subjected to a craniotomy. The animals were allocated randomly to receive a 3.75 ml/kg intravenous infusion of either 3.2 % HTS (group HTS, n = 8) or 20 % mannitol (group MTL, n = 8). Microcirculation in the cerebral cortex was evaluated using sidestream dark-field (SDF) imaging before and 20 min after the end of the 15-min HTS infusion. Global hemodynamic data were recorded, and blood samples for laboratory analysis were obtained at the time of SDF image recording.

Results

No differences in the microcirculatory parameters were observed between the groups before the use of osmotherapy. After osmotherapy, lower proportions of perfused small vessel density (P = 0.0474), perfused vessel density (P = 0.0457), and microvascular flow index (P = 0.0207) were observed in the MTL group compared with those in the HTS group.

Conclusions

Our findings suggest that an equivolemic, equiosmolar HTS solution better preserves perfusion of cortical brain microcirculation compared to MTL in a rabbit craniotomy model.

What's new in the management of traumatic brain injury on neuro ICU?

PURPOSE OF REVIEW

In recent years, we have begun to better understand how to monitor the injured brain, look for less common complications and importantly, reduce unnecessary and potentially harmful intervention. However, the lack of consensus regarding triggers for intervention, best neuromonitoring techniques and standardization of therapeutic approach is in need of more careful study. This review covers the most recent evidence within this exciting and dynamic field.

RECENT FINDINGS

The role of intracranial pressure monitoring has been challenged; however, it still remains a cornerstone in the management of the severely brain-injured patient and should be used to compliment other techniques, such as clinical examination and serial imaging.The use of multimodal monitoring continues to be refined and it may be possible to use them to guide novel brain resuscitation techniques, such as the use of exogenous lactate supplementation in the future.

SUMMARY

Neurocritical care management of traumatic brain injury continues to evolve. However, it is important not to use a 'one-treatment-fits-all' approach, and perhaps look to use targeted therapies to individualize treatment.

Comparison of equiosmolar concentrations of hypertonic saline and mannitol for intraoperative lax brain in patients undergoing craniotomy

Background:

Osmotherapy is the frequently used for the treatment of intracranial pressure. The purpose of the study was to compare the effect of equiosmolar solution of 3% hypertonic saline and 20% mannitol on brain relaxation in supratentorial tumor surgery.

Methods:

After institutional review board approval and written informed consent, 50 patients aged >18, Glasgow Coma Scale (GCS) >13 with ASA physical status 1, 2, and 3 scheduled to undergo craniotomy for supratentorial tumors were enrolled in this prospective, randomized study. Patients received 5 ml/kg of either 3% hypertonic saline (n = 25) or 20% mannitol (n = 25). Hemodynamic variables (heart rate [HR], SBP, DBP, MBP, and central venous pressure [CVP]), serum electrolytes, serum osmolality, urine output, and fluid balance were measured. The surgeon assessed the brain condition on four point scale (1 = perfectly relaxed, 2 = satisfactorily relaxed, 3 = firm brain, and 4 = bulging brain), who was blinded to study drug.

Results:

Brain relaxation was comparable in two groups and there was no significant difference (P = 0.633). The number of brain conditions classified as perfectly relaxed, satisfactorily relaxed, firm brain, and bulging brain in the HS group was 8, 13, 3, and 1, respectively, whereas it was 5, 17, 3, and 0, respectively, in the M group. There was no significant difference in hemodynamic variables between the two groups except CVP at 30 min (P = 048). Compared with mannitol, hypertonic saline caused increase in the serum osmolality at 120 min (P = 0.008) and in serum sodium at 120 min (P = 0.001). Urine output was higher with mannitol than hypertonic saline (P = 0.001).

Conclusion:

3% hypertonic saline and 20% mannitol are equally effective for brain relaxation in elective supratentorial tumor surgery and compared with mannitol, hypertonic saline was associated with less diuretic effect.

A prospective, randomized, double blind study to compare the effects of equiosmolar solutions of 3% hypertonic saline and 20% mannitol on reduction of brain-bulk during elective craniotomy for supratentorial brain tumor resection

Aims:

The aim of the study was to compare the effect of mannitol (M) and hypertonic saline (HTS) on brain relaxation and electrolyte balance.

Settings and Design:

Prospective, randomized, double-blind study.

Subjects and Methods:

A total of 114 patients with American Society of Anesthesiologists status II and III, scheduled to undergo craniotomy for supratentorial brain tumor resection were enrolled. Patients received 5 ml/kg 20% mannitol (n = 56) or 3% HTS (n = 58) at the start of scalp incision. Hemodynamics, fluid balance and electrolytes, were measured at 0, 15, 30, and 60 min and 6 h after infusion. Intensive Care Unit (ICU) stay between the two groups was also recorded. The surgeon assessed brain relaxation on a four-point scale (1 = Relaxed, 2 = Satisfactory, 3 = Firm, 4 = Bulging). Appropriate statistical tests were used for comparison; P < 0.05 was considered significant.

Results:

Brain relaxation conditions in the HTS group (relaxed/satisfactory/firm/bulging, n = 28/20/5/3) were better than those observed in the M group (relaxed/satisfactory/firm/bulging, n = 17/21/11/9). The levels of serum sodium were higher in the HTS group (P < 0.001). The average urine output was higher in the M group (5.50 ± 0.75 L) than in the HTS group (4.38 ± 0.72 L) (P < 0.005). There was no significant difference in fluid input, ICU stay, and hospital days between the two groups.

Conclusion:

We concluded that HTS provided better brain relaxation than mannitol during elective supratentorial brain tumor surgery, without affecting ICU and hospital stay.

Hypertonic saline for the treatment of intracranial hypertension

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

Autologous bone marrow mononuclear cells reduce therapeutic intensity for severe traumatic brain injury in children

OBJECTIVES

The devastating effect of traumatic brain injury is exacerbated by an acute secondary neuroinflammatory response, clinically manifest as elevated intracranial pressure due to cerebral edema. The treatment effect of cell-based therapies in the acute post-traumatic brain injury period has not been clinically studied although preclinical data demonstrate that bone marrow-derived mononuclear cell infusion down-regulates the inflammatory response. Our study evaluates whether pediatric traumatic brain injury patients receiving IV autologous bone marrow-derived mononuclear cells within 48 hours of injury experienced a reduction in therapeutic intensity directed toward managing elevated intracranial pressure relative to matched controls.

DESIGN

The study was a retrospective cohort design comparing pediatric patients in a phase I clinical trial treated with IV autologous bone marrow-derived mononuclear cells (n = 10) to a control group of age- and severity-matched children (n = 19).

SETTING

The study setting was at Children's Memorial Hermann Hospital, an American College of Surgeons Level 1 Pediatric Trauma Center and teaching hospital for the University of Texas Health Science Center at Houston from 2000 to 2008.

PATIENTS

Study patients were 5-14 years with postresuscitation Glasgow Coma Scale scores of 5-8.

INTERVENTIONS

The treatment group received 6 million autologous bone marrow-derived mononuclear cells/kg body weight IV within 48 hours of injury. The control group was treated in an identical fashion, per standard of care, guided by our traumatic brain injury management protocol, derived from American Association of Neurological Surgeons guidelines.

MEASUREMENTS AND MAIN RESULTS

The primary measure was the Pediatric Intensity Level of Therapy scale used to quantify treatment of elevated intracranial pressure. Secondary measures included the Pediatric Logistic Organ Dysfunction score and days of intracranial pressure monitoring as a surrogate for length of neurointensive care. A repeated-measure mixed model with marginal linear predictions identified a significant reduction in the Pediatric Intensity Level of Therapy score beginning at 24 hours posttreatment through week 1 (p < 0.05). This divergence was also reflected in the Pediatric Logistic Organ Dysfunction score following the first week. The duration of intracranial pressure monitoring was 8.2 ± 1.3 days in the treated group and 15.6 ± 3.5 days (p = 0.03) in the time-matched control group.

CONCLUSIONS

IV autologous bone marrow-derived mononuclear cell therapy is associated with lower treatment intensity required to manage intracranial pressure, associated severity of organ injury, and duration of neurointensive care following severe traumatic brain injury. This may corroborate preclinical data that autologous bone marrow-derived mononuclear cell therapy attenuates the effects of inflammation in the early post-traumatic brain injury period.

Hypertonic saline for the management of raised intracranial pressure after severe traumatic brain injury

Hyperosmolar agents are commonly used as an initial treatment for the management of raised intracranial pressure (ICP) after severe traumatic brain injury (TBI). They have an excellent adverse-effect profile compared to other therapies, such as hyperventilation and barbiturates, which carry the risk of reducing cerebral perfusion. The hyperosmolar agent mannitol has been used for several decades to reduce raised ICP, and there is accumulating evidence from pilot studies suggesting beneficial effects of hypertonic saline (HTS) for similar purposes. An ideal therapeutic agent for ICP reduction should reduce ICP while maintaining cerebral perfusion (pressure). While mannitol can cause dehydration over time, HTS helps maintain normovolemia and cerebral perfusion, a finding that has led to a large amount of pilot data being published on the benefits of HTS, albeit in small cohorts. Prophylactic therapy is not recommended with mannitol, although it may be beneficial with HTS. To date, no large clinical trial has been performed to directly compare the two agents. The best current evidence suggests that mannitol is effective in reducing ICP in the management of traumatic intracranial hypertension and carries mortality benefit compared to barbiturates. Current evidence regarding the use of HTS in severe TBI is limited to smaller studies, which illustrate a benefit in ICP reduction and perhaps mortality.

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

OBJECT

Increased intracranial pressure (ICP) in patients with traumatic brain injury (TBI) is associated with a higher mortality rate and poor outcome. Mannitol and hypertonic saline (HTS) have both been used to treat high ICP, but it is unclear which one is more effective. Here, the authors compare the effect of mannitol versus HTS on lowering the cumulative and daily ICP burdens after severe TBI.

METHODS

The Brain Trauma Foundation TBI-trac New York State database was used for this retrospective study. Patients with severe TBI and intracranial hypertension who received only 1 type of hyperosmotic agent, mannitol or HTS, were included. Patients in the 2 groups were individually matched for Glasgow Coma Scale score (GCS), pupillary reactivity, craniotomy, occurrence of hypotension on Day 1, and the day of ICP monitor insertion. Patients with missing or erroneous data were excluded. Cumulative and daily ICP burdens were used as primary outcome measures. The cumulative ICP burden was defined as the total number of days with an ICP of > 25 mm Hg, expressed as a percentage of the total number of days of ICP monitoring. The daily ICP burden was calculated as the mean daily duration of an ICP of > 25 mm Hg, expressed as the number of hours per day. The numbers of intensive care unit (ICU) days, numbers of days with ICP monitoring, and 2-week mortality rates were also compared between the groups. A 2-sample t-test or chi-square test was used to compare independent samples. The Wilcoxon signed-rank or Cochran-Mantel-Haenszel test was used for comparing matched samples.

RESULTS

A total of 35 patients who received only HTS and 477 who received only mannitol after severe TBI were identified. Eight patients in the HTS group were excluded because of erroneous or missing data, and 2 other patients did not have matches in the mannitol group. The remaining 25 patients were matched 1:1. Twenty-four patients received 3% HTS, and 1 received 23.4% HTS as bolus therapy. All 25 patients in the mannitol group received 20% mannitol. The mean cumulative ICP burden (15.52% [HTS] vs 36.5% [mannitol]; p = 0.003) and the mean (± SD) daily ICP burden (0.3 ± 0.6 hours/day [HTS] vs 1.3 ± 1.3 hours/day [mannitol]; p = 0.001) were significantly lower in the HTS group. The mean (± SD) number of ICU days was significantly lower in the HTS group than in the mannitol group (8.5 ± 2.1 vs 9.8 ± 0.6, respectively; p = 0.004), whereas there was no difference in the numbers of days of ICP monitoring (p = 0.09). There were no significant differences between the cumulative median doses of HTS and mannitol (p = 0.19). The 2-week mortality rate was lower in the HTS group, but the difference was not statistically significant (p = 0.56).

CONCLUSIONS

HTS given as bolus therapy was more effective than mannitol in lowering the cumulative and daily ICP burdens after severe TBI. Patients in the HTS group had significantly lower number of ICU days. The 2-week mortality rates were not statistically different between the 2 groups.