A Comparison of Hypertonic Saline and Mannitol on Intraoperative Brain Relaxation in Patients with Raised Intracranial Pressure during Supratentorial Tumors Resection: A Randomized Control Trial

Hypertonic Saline Solution Versus Mannitol for Brain Relaxation During Craniotomies: A Systematic Review and Updated Meta-Analysis

BACKGROUND AND OBJECTIVES

The preferred osmotic agent used for brain relaxation during craniotomies remains unclear, either mannitol (MAN) or hypertonic saline (HTS). Hence, we sought to compare these solutions in this population.

METHODS

MEDLINE, Embase, and Cochrane databases were systematically searched until August 02, 2023. Data were examined using the Mantel-Haenszel method and 95% CIs. Heterogeneity was assessed using I2 statistics. Meta-regression analysis was conducted to evaluate a possible link between Brain Relaxation Score and tumor volume. R, version 4.2.3, was used for statistical analysis.

RESULTS

A total of 16 randomized controlled trials and 1031 patients were included, of whom 631 (61%) underwent surgery for supratentorial tumor resection. Compared with MAN, HTS achieved better rates of brain relaxation (80% vs 71%; odds ratio [OR] 1.68; 95% CI 1.22-2.33; P = .001; I2 = 0%), which was also demonstrated in the subgroup analysis of patients with supratentorial brain tumor (78% vs 65%; OR 2.02; 95% CI 1.36-2.99; P = .0005; I2 = 0%); a minor number of patients requiring a second dose of osmotic agent (14% vs 28%; OR 0.43; 95% CI 0.27-0.69; P = .0003; I2 = 0%); a lower fluid intake (mean difference -475.9341 mL; 95% CI -818.8952 to -132.9730; P = .007; I2 = 88%); and lower urine output (mean difference -462.0941 mL; 95% CI -585.3020 to -338.8862; P = <.001; I2 = 96%). Hospital length of stay and focal neurological deficits did not reach a statistically significant difference between groups.

CONCLUSION

In this updated meta-analysis, consistent results suggest that HTS is associated with more beneficial outcomes than MAN in patients undergoing craniotomy.

Hyperosmolar Therapy in Elderly Neurosurgical Patients: Comparison of the Effect of Mannitol (20%) and Hypertonic Saline (3%) on Advanced Cardiovascular Parameters Using Transesophageal Echocardiography: A Preliminary Randomized Controlled Trial

OBJECTIVE

Osmotherapeutic agents increase the intravascular volume by withdrawing water from the brain followed by relative hypovolemia due to diuresis leading to significant changes in systemic hemodynamics which might have adverse consequences in the elderly. We studied the effect of mannitol (20%) and hypertonic saline (HTS) (3%) on left ventricular outflow tract velocity time integral (LVOT-VTI) and cardiac output (CO) in elderly patients undergoing supratentorial neurosurgical procedures using transesophageal echocardiography.

METHODS

We recruited 28 patients aged above 65 years undergoing supratentorial craniotomy who received equiosmolar solutions of 5.35 ml/kg of 3% HTS (group HS, n = 14) or 5 ml/kg of 20% mannitol (group M, n = 14). LVOT-VTI was recorded at baseline, 15, 30, 45, 60, and 90 minutes postinfusion and CO was derived. We also recorded heart rate, blood pressure, fluid balance, brain relaxation, vasopressor use, complications, and neurological outcome.

RESULTS

We found a significant decrease in LVOT-VTI at 45, and 60 minutes in group M as compared to group HS [mean (standard deviation), 16.76 (1.81) vs. 20.78 (1.87), P < 0.001, 17.4 (2.38) vs. 19.16 (2), P = 0.044, respectively]. We also found a corresponding significant fall in CO [3863.16 (845.87) vs. 4745.59 (1209.33) ml/minute, P = 0.034] and systolic blood pressure (P = 0.039), at 45 minutes in group M. Urine output was higher in group M (P < 0.001). All other parameters were comparable.

CONCLUSIONS

HTS appears to be associated with better systemic hemodynamics (LVOT-VTI, CO) while providing equivalent brain relaxation as mannitol in elderly patients. A future larger study is required to confirm our preliminary findings.

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.

Equiosmolar doses of hypertonic saline versus mannitol for brain relaxation in patients undergoing elective craniotomies: an updated systematic review and meta-analysis

Background

Hypertonic saline and mannitol are hyperosmolar agents frequently used to lower ICP and relax the brain during surgeries. Several methods have been used to achieve a good and relaxed brain, such as hyperventilation, cerebrospinal fluid drainage, head position correction, and administration of hyperosmolar agents. Comparing equiosmolar doses between hypertonic saline and mannitol in patients undergoing elective craniotomies is important to further notice the differences in several outcomes. This study aims to compare the outcome of hypertonic saline versus mannitol on brain relaxation in patients undergoing elective craniotomy.

Results

10 articles from 2007 to 2021 were included. Hypertonic saline is associated with better brain relaxation (OR  = 1.84, 95% CI 1.31–2.59; P = 0.001) but significantly increase blood natrium level, both serum and arterial (MD = 3.03, 95% CI 1.70–4.36; P =  < 0.001 and MD = 7.14, 95% CI 0.04–14.24; P =  < 0.001, respectively). Mannitol was associated with increased fluid input and urine output (SMD = − 0.56, 95% CI − 0.98 to − 0.15; P =  < 0.001 and SMD = − 0.96, 95% CI − 1.42 to − 0.50; P =  < 0.001, respectively). Serum osmolality and hemodynamic parameters difference was insignificant.

Conclusions

Hypertonic saline is associated with significantly better brain relaxation score and increased blood sodium level without increase in urine. This may prove to be clinically significant in patients with electrolyte imbalance.

Salted or sweet? Hypertonic saline or mannitol for treatment of intracranial hypertension

PURPOSE OF REVIEW

The aim of this review article is to present current recommendations regarding the use of hypertonic saline and mannitol for the treatment of intracranial hypertension.

RECENT FINDINGS

In recent years, a significant number of studies have been published comparing hypertonic saline with mannitol in patients with acute increased intracranial pressure, mostly caused by traumatic brain injury. Albeit several randomized controlled trials, systematic reviews and meta-analysis support hypertonic saline as more effective than mannitol in reducing intracranial pressure, no clear benefit in regards to the long-term neurologic outcome of these patients has been reported.

SUMMARY

Identifying and treating increased intracranial pressure is imperative in neurocritical care settings and proper management is essential to improve long-term outcomes. Currently, there is insufficient evidence from comparative studies to support a formal recommendation on the use of any specific hyperosmolar medication in patients with acute increased intracranial pressure.

The Optimal Dose and Concentration of Hypertonic Saline in Traumatic Brain Injury - A Systematic Review

Management of increased intracranial pressure in traumatic brain injury remains challenging in neurosurgical emergencies. The mainstay of medical management for increased intracranial pressure is hyperosmolar therapy with mannitol or hypertonic saline. Mannitol has been the “gold standard” osmotic agent for almost a century. Given its wide usage, there has been a dilemma of concern because of its adverse effects. Over the past few decades, hypertonic saline has become an increasingly better alternative. To date, there is no consensus on the optimal therapeutic dose and concentration of hypertonic saline for treating increased intracranial pressure. This systematic review aimed to compare the efficacy of hypertonic saline and mannitol in the management of traumatic brain injury and investigate the optimal dose and concentration of hypertonic saline for the treatment. Extensive research was conducted on PubMed, DOAJ, and Cochrane databases. Studies published within the last 20 years were included. Research articles in the form of meta-analyses, clinical trials, and randomized controlled trials were preferred. Those with ambiguous remarks, irrelevant correlations to the main issue, or a focus on other disorders were excluded. Nineteen studies were included in the systematic review. Eleven studies have stated that hypertonic saline and mannitol were equally efficacious, whereas eight studies have reported that hypertonic saline was superior. Moreover, 3% hypertonic saline was the main concentration most discussed in research. Improvements in increased intracranial pressure, cerebral perfusion pressure, survival rate, brain relaxation, and systemic hemodynamics were observed. Hypertonic saline is worthy of consideration as an excellent alternative to mannitol. This study suggests 3% hypertonic saline as the optimal concentration, with the therapeutic dose from 1.4 to 2.5 mL/kg, given as a bolus.

Equiosmolar hypertonic saline and mannitol for brain relaxation in patients undergoing supratentorial tumor surgery: A systematic review and meta-analysis

Background:

Hypertonic saline (HS) and mannitol are hyperosmolar agents that are usually used to reduce intracranial pressure (ICP) and provide a satisfactory brain relaxation. The aim of the study was to perform a systematic review and meta-analysis to compare the efficacy of HS and mannitol on brain relaxation intraoperatively in patient undergoing craniotomies for supra-tentorial brain tumors.

Methods:

A systematic review and meta-analysis of randomized control trials. We included randomized control trials that compared equiosmolar HS and mannitol in supratentorial tumors craniotomies and reported at least one of the following outcomes: degree of brain relaxation, ICP, central venous pressure, mean arterial pressure, perioperative fluid input, urine output, Na+ levels, and K+ levels. We searched Medline, Cochrane Central Register of Controlled Trials, and Embase using MESH terms and keywords. The bibliographic references of included studies and trial registries were also searched.

Results:

Seven articles were included. The degree brain of relaxation was comparable across the two groups with slight tendency toward HS (RR = 1.13, 95% CI 0.99–1.29; P = 0.08). Mannitol was associated with significantly higher urine output (standardized mean difference [SMD] = −1.33, 95% CI −1.56–−1.10; P < 0.001). Na⁺ levels were higher in HS group (SMD = 1.47, 95% CI 0.86–2.09; P < 0.001). Mannitol was associated with non-significant decrease in CVP and increase fluid input (SMD = 0.42, 95% CI 0.00–0.85 and SMD = −0.18, 95% CI −0.37–0.02, respectively).

Conclusion:

Both HS and mannitol are associated with satisfactory brain relaxation with a non-statistically significant tendency for HS to achieve better relaxation scores with mannitol resulting in higher urine output while HS with higher Na⁺ levels.

Evaluation of equiosmolar 20% mannitol, 3% hypertonic saline and 8.4% sodium bicarbonate on intraoperative brain relaxation and hemodynamic parameters in patients undergoing craniotomy for supratentorial tumors: a prospective randomized study

BACKGROUND

Research comparing 20% mannitol, 3% hypertonic saline and 8.4% sodium bicarbonate for intraoperative hyperosmolar therapy during supratentorial tumor excision is sparse. With the hypothesis that equiosmolar concentration of these agents will produce equivalent effects, this study was conducted to compare the effects on intraoperative brain relaxation and hemodynamics.

METHODS

The prospective study was conducted over a period of one year. Ninety patients, aged 18-60 years, American Society of Anesthesiologists class Ι and ΙΙ with supratentorial tumor and scheduled for surgery were randomized into three groups to receive equiosmolar 20% mannitol (group 1), 3% hypertonic saline (group 2) and 8.4% sodium bicarbonate (group 3). Primary outcome assessed was the effect on intraoperative brain relaxation score while hemodynamic parameters, changes in arterial blood gas parameters, serum electrolytes, serum osmolarity, urine output, fluid intake, post-operative course, hospital stay were the secondary outcomes.

RESULTS

Demographic characteristics, surgical and anesthetic variables, were comparable between the three groups. Brain relaxation scores were significantly better in group 3 compared to group 2 and group 1 respectively. Patients in group 1 had lower mean blood pressure and central venous pressure values, higher urine output, fluid intake compared to other groups. Patients of group 3 had significantly higher pH, bicarbonate, partial pressure of carbon dioxide, serum sodium and serum osmolarity values compared to groups 1 and 2.

CONCLUSIONS

Eight point four percent sodium bicarbonate solution infusion is associated with superior intraoperative brain relaxation scores and improved haemodynamic stability compared to equiosmolar 3% hypertonic saline solution and 20% mannitol.