Comparison of hypertonic saline and mannitol on whole blood coagulation in vitro assessed by thromboelastometry

Effect of mannitol on platelet function during elective craniotomy in adult patients with brain tumor

BACKGROUND

Mannitol is used in the treatment of raised intracranial pressure (ICP). The aim of this study was to investigate whether mannitol (MAN) leads to a relevant deterioration in platelet function in routine neurosurgical procedures.

METHODS

Thirty-eight patients undergoing elective craniotomy due to a brain tumor with elevated ICP were included. After induction of anesthesia a blood sample was taken (T1). The patients then received 1 g∙kg-1 MAN within 30 minutes. The second blood sample (T2) was obtained 60 minutes after T1. Blood samples were examined by means of aggregometry (Multiplate®; Roche, Basel, Switzertland) and PFA-100® tests (Siemens Healthineers, Erlangen, Germany).

RESULTS

No patient had clinical signs of increased bleeding. We could not find any deterioration in the aggregometry using Multiplate® (Roche), neither in the adenosine diphosphate (ADP), the arachidonic acid (ASPI), or the thrombin receptor activating protein (TRAP) test. PFA-100® (Siemens Healthineers) closing times (cT) showed a significant prolongation between T1 and T2: collagen/adenosine diphosphate (COL/ADP) test 79 s [70/99] and 91 s [81/109]; P=0.002); collagen/epinephrine (COL/EPI) test 109 s [92/129] and 122 s [94/159]; P=0.0004). A subgroup analysis showed that the patients who received isotonic balanced infusions only, had no prolongation of cT, whereas the patients who received additionally gelatin solution had a significant prolongation. COL/ADP: 78 s [70/98] and 91 s [82/133]; P=0.0004). COL/EPI: test 111 s [92/128] and 127 s [103/146]; P=0.0026). Except for individual outliers, the measured values were in the normal range.

CONCLUSIONS

In this study, we found no clinically relevant deterioration of platelet function in neurosurgical patients with increased ICP after administration of MAN. Changes that occurred were all within normal ranges.

In vitro effects of lactated Ringer's solution, hypertonic saline, hydroxyethyl starch, hypertonic saline/hydroxyethyl starch, and mannitol on thromboelastographic variables of canine whole blood

OBJECTIVE

To assess the in vitro effects of crystalloid and colloid IV fluids on the thromboelastographic (TEG) variables of canine whole blood.

DESIGN

In vitro experimental study.

SETTING

Veterinary teaching hospital.

ANIMALS

Twenty-two healthy dogs.

INTERVENTION

Citrated whole blood samples collected from healthy dogs were diluted with 3.4% hypertonic saline (HTS 3.4), 7% hypertonic saline (HTS 7), and 20% mannitol at 8% and 16% dilutions; hydroxyethyl starch 130/0.4 (HES 130/0.4) at 16% dilution; lactated Ringer's solution (LRS) at 16%, 33%, and 66% dilutions; and HTS 7-HES 130/0.4 at 25% and 50% dilutions. Kaolin-activated TEG analysis was concurrently performed on diluted and control (undiluted) samples.

MEASUREMENTS AND MAIN RESULTS

Dilution of canine whole blood with LRS compared to control reduced α angle and MA at both 33% (P = 0.009 and P = 0.011, respectively) and 66% dilution (P < 0.001 and P < 0.001, respectively), and prolonged K time at 66% dilution (P = 0.003). At 16% dilution, HTS 3.4, prolonged R time (P = 0.007), while mannitol, a fluid iso osmolar to HTS 3.4, prolonged K time (P = 0.006), reduced α angle (P < 0.001), MA (P = 0.046), and LY60 (P = 0.015). At 8% dilution, HTS 7, a fluid of high osmolarity and tonicity, prolonged R time (P = 0.009) and reduced MA (P = 0.015), while all measured TEG variables were altered at the 16% dilution (P < 0.01 for all variables). HES 130/0.4 reduced α angle (P = 0.031) and MA (P = 0.001) and increased LY60 (P < 0.001) at 16% dilution. Comparing different fluid types, HES 130/0.4 and HTS 3.4 had no to minor, mannitol intermediate, and HTS 7 profound effects on TEG variables (P < 0.05) when compared to LRS at the same dilution.

CONCLUSIONS

In vitro dilution of canine whole blood with commonly used IV fluids leads to thromboelastographic changes consistent with hypocoagulability in a dose dependent manner for all fluid types tested. Viscoelastic changes are also influenced by fluid characteristics, specifically tonicity and osmolarity.

Examining the Effect of Hypertonic Saline Administered for Reduction of Intracranial Hypertension on Coagulation

BACKGROUND

Hypertonic saline (23.4%, HTS) bolus administration is common practice for refractory intracranial hypertension, but its effects on coagulation are unknown. We hypothesize that 23.4% HTS in whole blood results in progressive impairment of coagulation in vitro and in vivo in a murine model of traumatic brain injury (TBI).

STUDY DESIGN

For the in vitro study, whole blood was collected from 10 healthy volunteers, and citrated native thrombelastography was performed with normal saline (0.9%, NS) and 23.4% HTS in serial dilutions (2.5%, 5%, and 10%). For the in vivo experiment, we assessed the effects of 23.4% HTS bolus vs NS on serial thrombelastography and tail-bleeding times in a TBI murine model (n = 10 rats with TBI and 10 controls).

RESULTS

For the in vitro work, clinically relevant concentrations of HTS (2.5% dilution) shortened time to clot formation and increased clot strength (maximum amplitude) compared with control and NS. With higher HTS dosing (5% and 10% blood dilution), there was progressive prolongation of time to clot formation, decreased angle, and decreased maximum amplitude. In the in vivo study, there was no significant difference in thrombelastography measurements or tail-bleeding times after bolus administration of 23.4% HTS compared with NS at 2.5% blood volume.

CONCLUSIONS

At clinically relevant dilutions of HTS, there is a paradoxical shortening of time to clot formation and increase in clot strength in vitro and no significant effects in a murine TBI model. However, with excess dilution, caution should be exercised when using serial HTS boluses in TBI patients at risk for trauma-induced coagulopathy.

Mannitol and the Combination of Mannitol and Gelatin Impair Whole Blood Coagulation and the Platelet Function In Vitro

Objective

Mannitol 20% and succinylated gelatin 4% are routinely used in neurosurgical procedures. The aim of this in vitro study was to explore the influence of both agents on blood coagulation and platelet function.

Methods

Blood from 21 healthy volunteers was obtained and then diluted so as to form five groups: (1) 7% dilution with mannitol; (2) 10% dilution with gelatin; (3) 17% dilution with isotonic balanced electrolyte solution; (4) 17% dilution with mannitol+gelatin; and (5) undiluted blood. The extrinsic thrombelastometry (EXTEM) and fibrin thrombelastometry (FIBTEM) tests were examined by rotational thrombelastometry via ROTEM®, and thrombocyte aggregometry with the aspirin inhibiting- (ASPI), adenosine diphosphate- (ADP), and thrombin-activating protein (TRAP) tests performed by Multiplate.

Results

In the EXTEM test clot formation time, the alpha angle, and maximum clot firmness were significantly reduced by mannitol and the combination of mannitol with gelatin. The platelet function tested in the ADP test was also significantly reduced with this combination.

Conclusion

In this in vitro study, clinically relevant dilutions of mannitol and gelatin showed a significant inhibition of whole blood coagulation and the platelet function, which could be detrimental in neurosurgical settings.

Contemporary Management of Increased Intraoperative Intracranial Pressure: Evidence-Based Anesthetic and Surgical Review

Increased intracranial pressure (ICP) is frequently encountered in the neurosurgical setting. A multitude of tactics exists to reduce ICP, ranging from patient position and medications to cerebrospinal fluid diversion and surgical decompression. A vast amount of literature has been published regarding ICP management in the critical care setting, but studies specifically tailored toward the management of intraoperative acute increases in ICP or brain bulk are lacking. Compartmentalizing the intracranial space into blood, brain tissue, and cerebrospinal fluid and understanding the numerous techniques available to affect these individual compartments can guide the surgical team to quickly identify increased brain bulk and respond appropriately. Rapidly instituting measures for brain relaxation in the operating room is essential in optimizing patient outcomes. Knowledge of the efficacy, rapidity, feasibility, and risks of the various available interventions can aid the team to properly tailor their approach to each individual patient. In this article, we present the first evidence-based review of intraoperative management of ICP and brain bulk.

Albumin combined with Mannitol impairs whole blood coagulation and platelet function in vitro

BACKGROUND

The indication of hydroxyethyl starch is currently under critical discussion and albumin 5% (ALB) has an increasing use in the operating theatre. Therefore, ALB is routinely used in neurosurgical procedures and often combined with mannitol 20% (MAN). Purpose of this in vitro study was to determine the influence of the combination of MAN and ALB on blood coagulation and platelet function.

METHODS

22 healthy volunteers were included into this study and 21 analysed. Blood was obtained and diluted into five groups: (1) 7% dilution with MAN, (2) 10% dilution with ALB (3) 17% dilution with isotonic balanced electrolyte solution, (4) 17% dilution with MAN + ALB and (5) undiluted blood as control group (CON). Rotational thrombelastometry via ROTEM® (EXTEM, FIBTEM-Test) and thrombocyte aggregometry via Multiplate® (ASPI, ADP and TRAP-test) were used to detect differences within the intervention groups and compared to the control group.

RESULTS

The maximum clot firmness in the FIBTEM test decreased under the normal range with the combination of MAN+ALB: 8mm (5.5-11) compared to CON: 15mm (12.5-20), p<0.05. Platelet function (ADP-test) showed significant decreases for ALB: 51 AUC (40-84) and MAN+ALB: 54 AUC (41-68) compared to CON: 92 AUC (75-101), p<0.05. Except in clotting time all other EXTEM tests of MAN+ALB subgroup showed significant impairment on blood coagulation compared to the control group.

CONCLUSIONS

In this in vitro study clinically relevant dilutions of MAN+ALB showed a significant inhibition of blood coagulation and platelet function. Further in vivo studies are necessary to confirm these results.

Neuroanesthesiology Update

We provide a synopsis of innovative research, recurring themes, and novel experimental findings pertinent to the care of neurosurgical patients and critically ill patients with neurological diseases. We cover the following broad topics: general neurosurgery, spine surgery, stroke, traumatic brain injury, monitoring, and anesthetic neurotoxicity.

Equiosmolar Solutions of Hypertonic Saline and Mannitol Do Not Impair Blood Coagulation During Elective Intracranial Surgery

BACKGROUND

The authors investigated the effect of equiosmolar, equivolemic solutions of 3% hypertonic saline (HS) and 20% mannitol on blood coagulation assessed by rotational thromboelastometry (ROTEM) and standard coagulation tests during elective craniotomy.

METHODS

In a prospective, randomized, double-blind trial, 40 patients undergoing elective craniotomy were randomized to receive 5 mL/kg of either 20% mannitol or 3% HS for intraoperative brain relaxation. Fibrinogen, activated partial thromboplastin time, prothrombin time, hemoglobin, hematocrit, and platelet count were simultaneously measured intraoperatively with ROTEM for EXTEM, INTEM, and FIBTEM analysis. ROTEM parameters were: clotting time (CT), clot formation time (CFT), maximum clot firmness (MCF), and α-angle.

RESULTS

No significant differences between groups were found in ROTEM variables CT, CFT, MCF, α-angle (EXTEM and INTEM), and MCF (FIBTEM) nor standard coagulation tests. ROTEM parameters did not show changes after administration of hyperosmolar solutions relating to basal values, except for an increase of CFT EXTEM (118±28 vs. 128±26 s) and decrease of CT INTEM (160±18 vs. 148±15 s) with values within normal range. Significant decreases from baseline levels were observed for hematocrit (-7%), platelet count (-10%), and fibrinogen (-13%) after HS infusion, and hematocrit (-9%), platelet count (-13%), and fibrinogen (-9%) after mannitol infusion, but remaining normal.

CONCLUSIONS

The use of 5 mL/kg of equiosmolar solutions of 3% HS and 20% mannitol applied to reach a brain relaxation during elective craniotomy does not induce coagulation impairment as evidenced by ROTEM and standard coagulation tests.

Comparison of the effects of 7.2% hypertonic saline and 20% mannitol on whole blood coagulation and platelet function in dogs with suspected intracranial hypertension - a pilot study

BACKGROUND

Hyperosmolar therapy with either mannitol or hypertonic saline (HTS) is commonly used in the treatment of intracranial hypertension (ICH). In vitro data indicate that both mannitol and HTS affect coagulation and platelet function in dogs. The aim of this study was to compare the effects of 20% mannitol and 7.2% HTS on whole blood coagulation using rotational thromboelastometry (ROTEM®) and platelet function using a platelet function analyzer (PFA®) in dogs with suspected ICH. Thirty client-owned dogs with suspected ICH needing osmotherapy were randomized to receive either 20% mannitol (5 ml/kg IV over 15 min) or 7.2% HTS (4 ml/kg IV over 5 min). ROTEM® (EXTEM® and FIBTEM® assays) and PFA® analyses (collagen/ADP cartridges) were performed before (T0), as well as 5 (T5), 60 (T60) and 120 (T120) minutes after administration of HTS or mannitol. Data at T5, T60 and T120 were analyzed as a percentage of values at T0 for comparison between groups, and as absolute values for comparison between time points, respectively.

RESULTS

No significant difference was found between the groups for the percentage change of any parameter at any time point except for FIBTEM® clotting time. Within each group, no significant difference was found between time points for any parameter except for FIBTEM® clotting time in the HTS group, and EXTEM® and FIBTEM® maximum clot firmness in the mannitol group. Median ROTEM® values lay within institutional reference intervals in both groups at all time points, whereas median PFA® values were above the reference intervals at T5 (both groups) and T60 (HTS group).

CONCLUSIONS

Using currently recommended doses, mannitol and HTS do not differ in their effects on whole blood coagulation and platelet function in dogs with suspected ICH. Moreover, no relevant impairment of whole blood coagulation was found following treatment with either solution, whereas a short-lived impairment of platelet function was found after both solutions.

The effect of hypertonic saline and mannitol on coagulation in moderate traumatic brain injury patients

BACKGROUND

Hyperosmolar therapy, using either hypertonic saline (HTS) or mannitol (MT), is considered the treatment of choice for intracranial hypertension, a disorder characterized by high intracranial pressure (ICP). However, hyperosmolar agents have been postulated to impair coagulation and platelet function. The aim of this study was to identify whether HTS and MT could affect coagulation in moderate traumatic brain injury (TBI) patients.

METHODS

In this prospective and randomized double-blind study, we included adult patients with moderate TBI. Patients were divided into two groups according to the type of hypertonic solution administered. Group A patients received 20% MT and group B patients received 3% HTS. Rotational thromboelastometry (ROTEM) parameters were used to assess coagulation and platelet function.

RESULTS

ROTEM parameters included CT (clotting time), CFT (clot formation time), maximum clot firmness (MCF) measured by MCF (EXTEM and INTEM), MCF (FIBTEM) and standard coagulation tests (p>0.05). No significant differences were found between the two groups. Moreover, ROTEM parameters did not show significant changes at different time points after administration of the hyperosmolar solutions (p>0.05). Conclusions Overall, use of 3% HTS and 20% MT for the control of ICP did not significantly affect patients' coagulation function. Therefore, hyperosmotic solution is safe and does not increase the risk of intracranial rebleeding.

A Comparison of the Effects of 20% Mannitol and 3% NaCl on Coagulation Parameters In Vitro using ROTEM: A Prospective Randomized Crossover Study

OBJECTIVE

The aim of the present study is to compare the effect of 20% mannitol and 3% NaCl on blood coagulation in vitro using rotational thromboelastometry (ROTEM).

METHODS

Twenty-millilitre blood samples were obtained from 15 volunteers. In each group, 2 mL blood samples were collected into both polypropylene tubes and EDTA tubes for ROTEM and hemogram analysis. After sampling, blood samples were diluted with test solutions. Group C (control): Only blood, Group M (mannitol): 7% vol 20% mannitol concentration in the blood, Group hypertonic saline (HS): 7% vol 3% hypertonic saline (NaCl) in the blood, Group M/H (mannitol and hydroxyethyl starch solutions [HES]): 6% vol 20% mannitol concentration and 8% vol HES in the blood and Group HS/H (hypertonic saline and HES): 6% vol 3% hypertonic saline concentration and 8% vol HES in the blood. The following thromboelastometric parameters were measured automatically: clotting time (CT) and clot formation time (CFT) with intrinsic activation by tissue factor (InTEM), CT, CFT and maximum clot firmness (MCF) with extrinsic activation by tissue factor (ExTEM) and MCF with FibTEM.

RESULTS

The ExTEM CT value was found to be significantly longer in the M/H group than in the controls. The ExTEM CFT median and percentile values were: group C: 85 s (70-95 s), group M: 115 s (94-128 s), group HS: 102 s (84-114 s), group M/H: 128 s (110-144 s) and group HS/H: 118 s (107-132 s). In all the groups, FibTEM MCF values were significantly lower than the control and also there was a significant difference between groups M and HS according to FibTEM MCF values.

CONCLUSION

Whole-blood coagulation disorder induced by these solutions is mainly dependent on fibrinogen and fibrin interaction. However, 3% HS has much less negative effect on coagulation.

Update on anesthesia for craniotomy

PURPOSE OF REVIEW

In this review, we present an update on the relationship between anesthesia and intraoperative hemodynamic complications, early postanesthesia recovery, postoperative pain and postoperative nausea and vomiting after craniotomy. We also review latest advances in education and research in neuroanesthesia for brain surgery.

RECENT FINDINGS

Insights from clinical reports published from January 2012 to April 2013 on anesthesia for craniotomy will be summarized. Recent findings address the need for a tight intraoperative hemodynamic monitoring - that should include aggressive prevention of arterial hypotension and cardiac arrhythmias - and a careful management of fluids and electrolytes balance. Data on the relationship between anesthesia (selection of anesthetics used intraoperatively) and early recovery demonstrate a limited benefit when ultra-short acting drugs (as remifentanil vs fentanyl) are used. Evidence on postoperative pain and postoperative nausea and vomiting contribute to define how to better prevent and treat these complications. Latest guidelines on training and research in neuroanesthesia define unique end points in this subspecialty.

SUMMARY

Neuroanesthesia for craniotomy should be aimed to ensure intraoperative loss of consciousness (unless awake craniotomy is the selected anesthesiological approach), pain control and an uneventful postoperative recovery, but should also be addressed to manipulate physiological variables including cerebral blood flow and to obtain optimal surgical exposure.

In vitro effects of 3% hypertonic saline and 20% mannitol on canine whole blood coagulation and platelet function

Background

Hyperosmolar therapy, using either mannitol or hypertonic saline (HTS), is considered the treatment of choice for intracranial hypertension. However, hyperosmolar agents may impair coagulation and platelet function, limiting their use in patients at risk for hemorrhage. Despite this, studies evaluating the effects of mannitol compared to other hyperosmolar agents in dogs are largely lacking. The aim of this study was to compare the in vitro effects on global hemostasis and platelet function of 20 % mannitol and 3 % HTS on canine blood.

Methods

Citrated whole blood from 15 healthy dogs was diluted with 0.9 % saline, 20 % mannitol and 3 % HTS in ratios of 1:16 and 1:8. Rotational thromboelastometry (ROTEM) was used to assess clotting time (CT), clot formation time (CFT) and maximal clot firmness (MCF) following extrinsic activation (Ex-tem) and after platelet inhibition (Fib-tem). A platelet function analyzer (PFA-100) was used to assess closure time (Ct_PFA).

Results

No significant differences were observed between untreated whole blood and samples diluted with saline. Samples diluted with both mannitol and HTS were hypocoagulable compared to untreated whole blood samples. At a dilution of 1:16, no significant differences were found between any measured parameter in samples diluted with saline compared to mannitol or HTS. At a 1:8 dilution, Ct_PFA was prolonged in samples diluted with mannitol and HTS compared to saline, and Ct_PFA was prolonged more with mannitol than HTS. Ex-tem CT was increased at a 1:8 dilution with mannitol compared to HTS. Ex-tem CFT was prolonged at a 1:8 dilution with both agents compared to saline, and was prolonged more with mannitol than HTS. Ex-tem MCF was reduced at a 1:8 dilution with both agents compared to saline.

Discussion and Conclusions

Data in this study indicate that both mannitol and HTS affect canine platelet function and whole blood coagulation in vitro in a dose-dependent fashion. The most pronounced effects were observed after high dilutions with mannitol, which impaired platelet aggregation, clot formation time, clot strength, and fibrin formation significantly more than HTS. Further in vivo studies are necessary before recommendations can be made.

The influence of excipients commonly used in freeze drying on whole blood coagulation dynamics assessed by rotational thromboelastometry

BACKGROUND

Lyophilized reagents are used on a daily basis in coagulation diagnostics. They often contain a number of excipients in addition to the active compound. Some of these excipients may, however, influence coagulation dynamics.

METHODS

Besides from plasmatic coagulation bulking agents may influence platelet properties. We therefore studied the influence of a variety of bulking agents (glycine, mannitol, sucrose and trehalose) as well as a surfactant (Tween® 80) on whole blood coagulation using thromboelastometry (ROTEM®) and platelet function analysis (ROTEM® platelet).

RESULTS

Both disaccharides as well as Tween® 80 did not influence whole blood coagulation in the concentration range investigated. The addition of glycine and mannitol solutions to the ROTEM® measurement leads to an impaired clot formation as well as overall clot strength while clotting initiation remained barely influenced. Hypertonic glycine and mannitol solutions exhibit different clot formation impairment when correlated to their osmolar concentration and compared to equally osmolar NaCl-solutions. The effect of glycine was assigned to fibrin formation impairment identified with the FIBTEM assay. Platelet function analysis revealed that hypertonic glycine solutions do not alter platelet function but hypertonic mannitol and NaCl solutions do.

CONCLUSIONS

While the influence observed for glycine may be due to fibrinogen precipitation, the mechanism of mannitol appears to be more complex as platelet function as well as fibrin-based clot formation are influenced. This study therefore demonstrates the necessity to check for coagulation impairment due to compounds contained in lyophilized reagents.

In vitro assessment of effects of hyperglycemia on the optical properties of blood during coagulation using optical coherence tomography

No published reports have demonstrated the capability of the optical coherence tomography technique for quantifying the optical coherence tomography signal slope, 1/e light penetration depth, and attenuation coefficient of hyperglycemic blood by an in vitro assessment. The purpose of this study was to investigate the effects of hyperglycemia on optical properties during in vitro blood coagulation by optical coherence tomography. Normal whole blood acted as the control group. After 1-h coagulation, the average optical coherence tomography signal slope decreased approximately 23.3 and 16.7%, and the 1/e light penetration depths increased approximately 21.5 and 19.2% for the control and hyperglycemic groups, respectively. It could be seen from the 1/e light penetration depth evolution curves that the blood coagulation time was about (425 ± 19) s for normal whole blood and (367 ± 15) s for the hyperglycemic blood. The coagulation time decreased 13.6% for the hyperglycemic blood compared with that for normal whole blood. There was statistically significant difference in blood coagulation time between the hyperglycemic and normal whole blood (p < 0.05). The results suggested that hyperglycemia has a procoagulant effect. Our experiment was the first reported study of monitoring hyperglycemic blood coagulation using OCT. We conclude that OCT is potential technique to quantify and follow the liquid-gel transition of hyperglycemic blood coagulation.

Effective treatment of refractory intracranial hypertension after traumatic brain injury with repeated boluses of 14.6% hypertonic saline

Object

Normal intracranial pressure (ICP) and cerebral perfusion pressure (CPP) have been identified as favorable prognostic factors in the outcome of patients with traumatic brain injuries (TBIs). Osmotic diuretics and hypertonic saline (HTS) are commonly used to treat elevated ICP in patients with TBI; however, sustained effects of repeated high-concentration HTS boluses for severely refractory ICP elevation have not been studied. The authors' goal in this study was to determine whether repeated 14.6% HTS boluses were efficacious in treating severely refractory intracranial hypertension in patients with TBI.

Methods

In a prospective cohort study in a neurocritical care unit, adult TBI patients with sustained ICP > 30 mm Hg for more than 30 minutes after exhaustive medical and/or surgical therapy received repeated 15-minute boluses of 14.6% HTS over 12 hours through central venous access.

Results

Response to treatment was evaluated in 11 patients. Within 5 minutes of bolus administration, mean ICP decreased from 40 to 33 mm Hg (30% reduction, p < 0.05). Intracranial pressure–lowering effects were sustained for 12 hours (41% reduction, p < 0.05) with multiple boluses (mean number of boluses 7 ± 5.5). The mean CPP increased 22% and 32% from baseline at 15 and 30 minutes, respectively (p < 0.05). The mean serum sodium level (SNa) at baseline was 155 ± 7.1 mEq/L, and after multiple boluses of 14.6% HTS, SNa at 12 hours was 154 ± 7.1 mEq/L. The mean heart rate, systolic blood pressure, blood urea nitrogen, and creatinine demonstrated no significant change throughout the study.

Conclusions

The subset of TBI patients with intracranial hypertension that is completely refractory to all other medical therapies can be treated effectively and safely with repeated boluses of 14.6% HTS rather than a one-time dose.

Anesthetic management of a patient with hemophilia A with spontaneous acute subdural hematoma

Intracranial hemorrhage in patients with hemophilia is associated with high mortality and sequelae. We report the case of 50-year-old man with Hemophilia A, who presented with spontaneous acute subdural hematoma and underwent craniotomy for clot evacuation. The patient received Factor VIII infusions perioperatively along with other measures to decrease blood loss. The patient presented with signs of high intracranial tension and received 3% saline intraoperatively and postoperatively to prevent brain edema. Recommendations for perioperative preparation and management of hemophilia, especially in the setting of emergency major surgery are reviewed.

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.

Thromboelastometry during intraoperative transfusion of fresh frozen plasma in pediatric neurosurgery

Normal blood coagulation is essential in pediatric neurosurgery because of the risk of abundant bleeding, and therefore it is important to avoid transfusion of fluids that might interfere negatively with the coagulation process. There is a lack of transfusion guidelines in massive bleeding with pediatric neurosurgical patients, and early use of blood compounds is partly controversial. We describe two pediatric patients for whom fresh frozen plasma (FFP) infusion was started at the early phase of brain tumor surgery to prevent intraoperative coagulopathy and hypovolemia. In addition to the traditional laboratory testing, modified thromboelastometry analyses were used to detect possible disturbances in coagulation. Early transfusion of FFP and red blood cells preserved the whole blood coagulation capacity. Even with continuous FFP infusion, fibrin clot firmness was near to critical value at the end of surgery despite increased preoperative values. By using FFP instead of large amounts of crystalloids and colloids when major blood loss is expected, blood coagulation is probably less likely to be impaired. Our results indicate, however, that the capacity of FFP to correct fibrinogen deficit is limited.

Slack brain in meningioma surgery through lateral supraorbital approach

BACKGROUND

Surgery of skull base meningiomas by the lateral supraorbital (LSO) approach requires relaxed brain. Therefore, we assessed combined effects of the elements of neuroanesthesia on neurosurgical conditions during craniotomy.

METHODS

The anesthesiological and surgical charts of 66 olfactory groove, 73 anterior clinoidal, and 52 tuberculum sellae meningioma patients operated on by the senior author (J.H.) at the Department of Neurosurgery of Helsinki University Central Hospital, Helsinki, Finland, between September 1997 and August 2010, were retrospectively analyzed.

RESULTS

One-hundred fifty-four (82%) patients had good surgical conditions, and this was achieved by (1) elevating the head 20 cm above the cardiac level in all patients with only slightly lateral turn or neck flexion, (2) administering mannitol preoperatively in medium or large meningiomas (n = 60), (3) maintaining anesthesia with propofol infusion (n = 46) or volatile anesthetics (n = 107) also in patients with large tumors (n = 37), and (4) controlling intraoperative hemodynamics. Brain relaxation was satisfactory in 18 (10%) and poor in 15 (8%) patients. The median intraoperative blood loss was 200 (range, 0-2000) ml. Only 9% of patients received red blood cell transfusion. The median time to extubation was 18 (range, 8-105) min after surgery. Extubation time correlated with the patients' preoperative clinical status and the size of tumor but not with the modality of anesthesia.

CONCLUSIONS

Slack brain during the LSO approach is achieved by correct patient positioning, preoperative mannitol, either by propofol or in small tumors inhaled anesthetics, and optimizing cerebral perfusion pressure. Under these circumstances, intraoperative brain swelling is prevented, bleeding is minimal, and no blood transfusions are needed.