Hydroelectrolytic balance and cerebral relaxation with hypertonic isoncotic saline versus mannitol (20%) during elective neuroanesthesia

A Brief Explanation on Surgical Approaches for Treatment of Different Brain Tumors

The main goal of brain tumor surgery is to achieve gross total tumor resection without postoperative complications and permanent new deficits. However, when the lesion is located close or within eloquent brain areas, cranial nerves, and/or major brain vessels, it is imperative to balance the extent of resection with the risk of harming the patient, by following a so-called maximal safe resection philosophy. This view implies a shift from an approach-guided attitude, in which few standard surgical approaches are used to treat almost all intracranial tumors, to a pathology-guided one, with surgical approaches actually tailored to the specific tumor that has to be treated with specific dedicated pre- and intraoperative tools and techniques. In this chapter, the basic principles of the most commonly used neurosurgical approaches in brain tumors surgery are presented and discussed along with an overview on all available modern tools able to improve intraoperative visualization, extent of resection, and postoperative clinical outcome.

Effect of intraoperative goal-directed fluid therapy on the postoperative brain edema in patients undergoing high-grade glioma resections: a study protocol of randomized control trial

Introduction

Brain edema is the most frequent postoperative complication after brain tumor resection, especially in patients with high-grade glioma. However, the effect of SVV-based goal-directed fluid therapy (GDFT) on postoperative brain edema and the prognosis remain unclear.

Methods and analysis

This is a prospective, randomized, double-blinded, parallel-controlled trial aiming to observe whether stroke volume variation (SVV)-based GDFT could improve the postoperative brain edema in patients undergoing supratentorial high-grade gliomas compared with traditional fluid therapy. The patient will be given 3 ml/kg hydroxyethyl starch solution when the SVV is greater than 15% continuously for more than 5 min intraoperatively. The primary outcome will be postoperative cerebral edema volume on brain CT within 24 h.

Ethics and dissemination

This trial has been registered at ClinicalTrials.gov (NCT03323580) and approved by the Ethics Committee of Beijing Tiantan Hospital, Capital Medical University (reference number: KY2017-067-02). The findings will be disseminated in peer-reviewed journals and presented at national or international conferences relevant to the subject fields.

Trial registration

ClinicalTrials.gov NCT03323580 (First posted: October 27, 2017; Last update posted: February 11, 2022).

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06859-9.

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.

Comparison of Preoperative Hypertonic Saline versus Mannitol for Intraoperative Brain Relaxation and Early Postoperative Outcome among Patients with Cerebral Low-grade Glioma: A Prospective Study

Introduction:

Hypertonic saline (HS) has an important role in the treatment of raised intracranial pressure after traumatic brain injury. This study evaluates the efficacy and safety of HS and its impact on the postoperative course of patients undergoing craniotomy for low-grade gliomas.

Materials and Methods:

Sixty patients with supratentorial low-grade glioma were enrolled. All patients were anesthetized and operated with the same team and protocol. They successively received either HS or mannitol just before surgery. The amount of brain edema was classified according to the dural tension score (I–III) just after craniotomy and before dural opening. Other intraoperative measurements (such as urine output, need, and dosage of other diuretic agents) and postoperative findings (intensive care unit [ICU] and hospital stay, corticosteroid demand, and confusion period) were also assessed. Pre- and postoperative serum S100B levels were documented in both groups.

Results:

The dural tension score was not significantly different among the two groups: severe tension in six and five patients in the mannitol and HS groups, respectively. HS group had a significantly lower amount of diuresis (609 vs. 725 ml) during surgery. Patients in the HS group had shorter ICU stay (16.3 vs. 27.9 h) and shorter duration of corticosteroid therapy after surgery (3.4 vs. 5.2 days).

Conclusion:

HS infusion just before the onset of craniotomy is at least as effective as mannitol in controlling intraoperative brain edema in patients with supratentorial glioma. Improved early postoperative course and lower degrees of S100B rise after craniotomy seen in the HS group needs to be explained in more detailed studies.

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

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

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

OBJECTIVE

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Definition, evaluation, and management of brain relaxation during craniotomy

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

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.

Mannitol versus hypertonic saline for brain relaxation in patients undergoing craniotomy

BACKGROUND

Patients with brain tumour usually suffer from increased pressure in the skull due to swelling of brain tissue. A swollen brain renders surgical removal of the brain tumour difficult. To ease surgical tumour removal, measures are taken to reduce brain swelling, often referred to as brain relaxation. Brain relaxation can be achieved with intravenous fluids such as mannitol or hypertonic saline. This review was conducted to find out which of the two fluids may have a greater impact on brain relaxation.

OBJECTIVES

The objective of this review was to compare the effects of mannitol versus those of hypertonic saline on intraoperative brain relaxation in patients undergoing craniotomy.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2013, Issue 10), MEDLINE via Ovid SP (1966 to October 2013) and EMBASE via Ovid SP (1980 to October 2013). We also searched specific websites, such as www.indmed.nic.in, www.cochrane-sadcct.org and www.Clinicaltrials.gov.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that compared the use of hypertonic saline versus mannitol for brain relaxation. We also included studies in which any other method used for intraoperative brain relaxation was compared with mannitol or hypertonic saline. Primary outcomes were longest follow-up mortality, Glasgow Outcome Scale score at three months and any adverse events related to mannitol or hypertonic saline. Secondary outcomes were intraoperative brain relaxation, intensive care unit (ICU) stay, hospital stay and quality of life.

DATA COLLECTION AND ANALYSIS

We used standardized methods for conducting a systematic review, as described by the Cochrane Handbook for Systematic Reviews of Interventions. Two review authors independently extracted details of trial methodology and outcome data from reports of all trials considered eligible for inclusion. All analyses were made on an intention-to-treat basis. We used a fixed-effect model when no evidence was found of significant heterogeneity between studies, and a random-effects model when heterogeneity was likely.

MAIN RESULTS

We included six RCTs with 527 participants. Only one RCT was judged to be at low risk of bias. The remaining five RCTs were at unclear or high risk of bias. No trial mentioned the primary outcomes of longest follow-up mortality, Glasgow Outcome Scale score at three months or any adverse events related to mannitol or hypertonic saline. Three trials mentioned the secondary outcomes of intraoperative brain relaxation, hospital stay and ICU stay; quality of life was not reported in any of the trials. Brain relaxation was inadequate in 42 of 197 participants in the hypertonic saline group and in 68 of 190 participants in the mannitol group. The risk ratio for brain bulge or tense brain in the hypertonic saline group was 0.60 (95% confidence interval (CI) 0.44 to 0.83, low-quality evidence). One trial reported ICU and hospital stay. The mean (standard deviation (SD)) duration of ICU stay in the mannitol and hypertonic saline groups was 1.28 (0.5) and 1.25 (0.5) days (P value 0.64), respectively; the mean (SD) duration of hospital stay in the mannitol and hypertonic saline groups was 5.7 (0.7) and 5.7 (0.8) days (P value 1.00), respectively

AUTHORS' CONCLUSIONS

From the limited data available on the use of mannitol and hypertonic saline for brain relaxation during craniotomy, it is suggested that hypertonic saline significantly reduces the risk of tense brain during craniotomy. A single trial suggests that ICU stay and hospital stay are comparable with the use of mannitol or hypertonic saline. However, focus on other related important issues such as long-term mortality, long-term outcome, adverse events and quality of life is needed.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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