Hypertonic saline improves brain resuscitation in a pediatric model of head injury and hemorrhagic shock

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.

The role of hypertonic saline dextran in trauma resuscitation

Modern trauma management has recognized the importance of using conservative fluid resuscitation regimes in order to prevent complications from fluid overload arising. Hypertonic/hyperoncotic fluids appear to provide an ideal means of facilitating this, requiring only small volumes to rapidly elevate blood pressure. Hypertonic saline dextran (HSD) was introduced in 1985 but its take up has been slow, a large part of this has been due to the lack of human trials and concerns about complications.

The current evidence has been reviewed and it is clear that HSD is an efficient means of correcting hypotension, doing so mainly by the mobilizing endogenous water. It is becoming apparent that early administration has the potential to modulate the inflammatory cascade in patients at risk of developing adult respiratory distress syndrome (ARDS) and multiorgan failure. This is reflected in the handful of human trials that show a trend towards increased survival (particularly for head injuries) and a possible reduction in ARDS. The side effect profile appears to be good, even in the presence of dehydration or penetrating trauma.

Published human trials have methodological problems and lack of power of study this has led to a reliance on animal studies. Clearly there is great potential, but before large-scale prehospital usage can be justified further well-conducted randomized human trials are needed.

A comparison of 3% hypertonic saline and mannitol for brain relaxation during elective supratentorial brain tumor surgery

BACKGROUND

In this study, we compared the effects of 3% hypertonic saline (HTS) and 20% mannitol on brain relaxation during supratentorial brain tumor surgery, intensive care unit (ICU) stays, and hospital days.

METHODS

This prospective, randomized, and double-blind study included patients who were selected for elective craniotomy for supratentorial brain tumors. Patients received either 160 mL of 3% HTS (HTS group, n = 122) or 150 mL of 20% mannitol infusion (M group, n = 116) for 5 minutes at the start of scalp incision. The PCO(2) in arterial blood was maintained within 35 to 40 mm Hg, arterial blood pressure was controlled within baseline values +/-20%, and positive fluid balance was maintained intraoperatively at a rate of 2 mL/kg/h. Outcome measures included fluid input, urine output, arterial blood gases, serum sodium concentration, ICU stays, and hospital days. Surgeons assessed the condition of the brain as "tight," "adequate," or "soft" immediately after opening the dura.

RESULTS

Brain relaxation conditions in the HTS group (soft/adequate/tight, n = 58/43/21) were better than those observed in the M group (soft/adequate/tight, n = 39/42/35; P = 0.02). The levels of serum sodium were higher in the HTS group compared with the M group over time (P < 0.001). The average urine output in the M group (707 mL) was higher than it was in the HTS group (596 mL) (P < 0.001). There were no significant differences in fluid input, ICU stays, and hospital days between the 2 groups.

CONCLUSIONS

Our results suggest that HTS provided better brain relaxation than did mannitol during elective supratentorial brain tumor surgery, whereas it did not affect ICU stays or hospital days.

The effects of hypertonic saline and nicotinamide on sensorimotor and cognitive function following cortical contusion injury in the rat

Hypertonic saline (HTS) is an accepted treatment for traumatic brain injury (TBI). However, the behavioral and cognitive consequences following HTS administration have not thoroughly been examined. Recent preclinical evidence has suggested that nicotinamide (NAM) is beneficial for recovery of function following TBI. The current study compared the behavioral and cognitive consequences of HTS and NAM as competitive therapeutic agents for the treatment of TBI. Following controlled cortical impact (CCI), bolus administrations of NAM (500 mg/kg), 7.5% HTS, or 0.9% saline Vehicle (1.0 mL/kg) were given at 2, 24, and 48 h post-CCI. Behavioral results revealed that animals treated with NAM and HTS showed significant improvements in beam walk and locomotor placing compared to the Vehicle group. The Morris water maze (MWM) retrograde amnesia test was conducted on day 12 post-CCI and showed that all groups had significant retention of memory compared to injured, Vehicle-treated animals. Working memory was also assessed on days 8-20 using the MWM. The NAM and Vehicle groups quickly acquired the task; however, HTS animals showed no acquisition of this task. Histological examinations revealed that the HTS-treated animals lost significantly more cortical tissue than either the NAM or Vehicle-treated animals. HTS-treated animals showed a greater loss of hippocampal tissue compared to the other groups. In general, NAM showed a faster rate of recovery than HTS without this associated tissue loss. The results of this study reiterate the strengths of NAM following injury and show concerns with bolus administrations of HTS due to the differential effects on cognitive performance and apparent tissue loss.

Long-term outcomes and prognostic factors in pediatric patients with severe traumatic brain injury and elevated intracranial pressure

OBJECT

The management strategies and outcomes in pediatric patients with elevated intracranial pressure (ICP) following severe traumatic brain injury (TBI) are examined in this study.

METHODS

This study was a retrospective review of a prospectively acquired pediatric trauma database. More than 750 pediatric patients with brain injury were seen over a 10-year period. Records were retrospectively reviewed to determine interventions for correcting ICP, and surviving patients were contacted prospectively to determine functional status and quality of life. Only patients with 2 years of follow-up were included in the study.

RESULTS

Ninety-six pediatric patients (age range 3-18 years) were identified with a Glasgow Coma Scale score<8 and elevated ICP>20 mm Hg on presentation. The mean injury severity score was 65 (range 30-100). All patients were treated using a standardized head injury protocol. The mean time course until peak ICP was 69 hours postinjury (range 2-196 hours). Intracranial pressure control was achieved in 82 patients (85%). Methods employed to achieve ICP control included maximal medical therapy (sedation, hyperosmolar therapy, and paralysis) in 34 patients (35%), ventriculostomy in 23 patients (24%), and surgery in 39 patients (41%). Fourteen patients (15%) had refractory ICP despite all interventions, and all of these patients died. Seventy-two patients (75%) were discharged from the hospital, whereas 24 (25%) died during hospitalization. Univariate and multivariate analysis revealed that the presence of vascular injury, refractory ICP, and cisternal effacement at presentation had the highest correlation with subsequent death (p<0.05). Mean follow-up was 53 months (range 11-126 months). Three patients died during the follow-up period (2 due to infections and 1 committed suicide). The mean 2-year Glasgow Outcome Scale score was 4 (median 4, range 1-5). The mean patient competency rating at follow-up was 4.13 out of 5 (median 4.5, range 1-4.8). Univariate analysis revealed that the extent of intracranial and systemic injuries had the highest correlation with long-term quality of life (p<0.05).

CONCLUSIONS

Controlling elevated ICP is an important factor in patient survival following severe pediatric TBI. The modality used for ICP control appears to be less important. Long-term follow-up is essential to determine neurocognitive sequelae associated with TBI.

Pediatric trauma resuscitation: initial fluid management

Fluid management is a vital component in the resuscitative care of the injured child. The goal of fluid resuscitation is to restore tissue perfusion without compromising the body's natural compensatory mechanism. Recent literature has questioned the timing, type, and amount of fluid administration during the resuscitative phase. When managing a pediatric resuscitation, it is imperative to use a variety of age-appropriate physiologic parameters because reliance on blood pressure alone will lead to delayed recognition of shock. Establishing vascular access, via peripheral intravenous, central venous, or intraosseous catheter, should be a high nursing priority. Hemorrhage control and fluid resuscitation of an injured child remains a top priority of trauma care. Early intravenous access with appropriate fluid administration continues to be a universal treatment for the hypotensive trauma patient. Fluid resuscitation in the early phase of care, whether in the field, emergency department, or operating room, should be targeted toward perfusing critical organs, such as the brain and heart. Once obvious bleeding is controlled, the overall goal for fluid management centers on maintaining oxygen delivery to perfuse vital structures with enough oxygen and energy substrates to maintain cellular function, thus avoiding tissue ischemia. However, specific issues around timing and type of fluid administration, once thought to be straightforward, have triggered increasing investigation of current beliefs.

Resuscitation of Hypotensive Head-Injured Patients: Is Hypertonic Saline the Answer?

Hypertonic saline (HTS) may decrease intracranial pressure (ICP) in severe traumatic brain injury (STBI) and effectively resuscitates hypotensive patients. No data exist on institutional standardization of HTS for hypotensive patients with STBI. It remains unclear how HTS affects brain tissue oxygenation (PbtO2) in STBI. We hypothesized HTS could be safely standardized in patients with STBI and would lower ICP while improving cerebral perfusion pressure (CPP) and PbtO2. Under institutional guidelines in a Level I trauma center, 12 hypotensive STBI intensive care unit subjects received HTS. Inclusion criteria included mean arterial pressure (MAP) ≤ 90 mmHg, Glasgow Coma Scale (GCS) ≤ 8, ICP ≥ 20 mmHg, and serum [Na+] < 155 mEq/L. All patients underwent ICP monitoring. Hemodynamics, CPP, ICP, and PbtO2 data were collected before and hourly for 6 hours after HTS infusion. Guideline criteria compliance was greater than 95 per cent. No major complications occurred. Mean ICP levels dropped by 45 per cent (P < 0.01) and this drop persisted for 6 hours. CPP levels increased by 20 per cent (P < 0.05). PbtO2 remained persistently elevated for all time points after HTS infusion. Institutional use of HTS in STBI can be safely implemented in a center caring for neurotrauma patients. HTS infusion in hypotensive STBI reduces ICP and raises CPP. Brain tissue oxygenation tends to improve after HTS infusion.

[Controlled hypernatremia]

Hypernatremia exerts its main effect on the brain through the osmotic gradient it creates on either side of the blood brain barrier, which is impermeable to sodium. This generates a transfer of water from the intracellular to the vascular sector leading to temporary cell shrinkage. Osmoregulation permits cerebral cells to accumulate osmoactive molecules in order to restore their initial volume. It has been demonstrated in animals with brain injury that intracellular dehydration occurs essentially in the nonlesioned hemisphere. In most experimental studies, the reduction in cerebral volume obtained by hypertonic saline (HS) perfusion is accompanied by an intracranial pressure decrease, even under hemorrhagic shock conditions. Initially, clinical studies successfully used HS, as an alternative to mannitol, in the treatment of acute and refractory intracranial hypertension. Then continuous infusion of HS, with the objective of inducing hypernatremia, had produced encouraging effects on intracranial pressure control. However, these results were limited to non-randomized studies, without control groups and mainly in pediatric patients. Nevertheless, the use of HS on intracranial hypertension, refractory to conventional treatments, could be reasonable under strict monitoring of natremia as well as its adverse effects.

Volume replacement with lactated Ringer's or 3% hypertonic saline solution during combined experimental hemorrhagic shock and traumatic brain injury

BACKGROUND

The devastating effects of hypotension on head-trauma-related mortality are well known. This study evaluates the systemic and cerebral hemodynamic responses to volume replacement with 3% hypertonic saline (HSS) or lactated Ringer's solution (LR), during the acute phase of hemorrhagic shock (HS) associated with traumatic brain injury (TBI).

METHODS

Fifteen dogs were assigned to one of three groups (n = 5, each) according to the volume replacement protocol, infused after TBI (brain fluid percussion, 4 atm) and epidural balloon to an intracranial pressure (ICP) higher than 20 mm Hg and HS, induced by blood removal to a mean arterial pressure (MAP) of 40 mm Hg in 5 minutes: Group HS+TBI+HSS (8 mL/kg of 3% HSS), HS+TBI+LR (16 mL/kg LR), and Group HS+TBI (controls, no fluids). We simulated treatment during prehospital and early hospital admission. Groups HS+ TBI and HS+TBI+LR received shed blood infusion to a target hematocrit of 30%. Measurements included shed blood volume, fluid volume infused to restore MAP, MAP, cardiac output, cerebral perfusion pressure, cerebral and systemic lactate, and oxygen extraction ratios.

RESULTS

Fluid replacement with HSS 3% or LR promoted major hemodynamic benefits over control animals without luids. Cerebral perfusion pressure was higher than controls and similar between treated groups; however, HSS 3% infusion was associated with lower ICP during the "early hospital phase" and a higher serum sodium and osmolarity.

CONCLUSION

In the event of severe head trauma and hemorrhagic shock, the use of HSS 3% and larger volumes of LR promote similar systemic and cerebral hemodynamic benefits. However, a lower ICP was observed after HSS 3% than after LR.

The Effect of Hypertonic (3%) Saline With and Without Furosemide on Plasma Osmolality, Sodium Concentration, and Brain Water Content After Closed Head Trauma in Rats

Adding furosemide (F) to mannitol causes a greater decrease of brain volume, intracranial pressure, and brain water content (BW) as compared with mannitol alone. We examined whether adding F to hypertonic saline (HS) causes less increase of BW early after closed head trauma (CHT) as compared with HS alone. With institutional approval, 125 rats underwent sham surgery or CHT and then immediately received no treatment, HS (1.2 g/kg, 3% solution), or HS + F (2 mg/kg). In groups 1-10 (n = 8/group), the percent BW content was determined at 30, 60, or 120 minutes. In groups 11-14 (n = 8/group), physiologic values were determined at 0, 30, 60, and 120 minutes. At 120 minutes, the increase of BW caused by CHT (sham = 78.9 +/- 0.6% and CHT = 81.5 +/- 2.2%, mean +/- SD) was prevented by HS + F (78.0 +/- 0.8%) but not by HS (80.7 +/- 2.2%). Both HS and HS + F similarly increased plasma osmolality and sodium concentration. Post-CHT hypotension and acidosis (30 and 60 minutes) and decrease of hemoglobin concentration (120 minutes) were less with HS + F than with HS. We conclude that adding F to HS decreases BW without causing more increase of osmolality and Na than that caused by HS alone.

Pelvic fractures and associated injuries in children

BACKGROUND

Pelvic fractures occur uncommonly in children. Despite serious sequelae, they have been infrequently reviewed.

METHODS

We conducted a retrospective review of admissions to our institution from January 1983 to December 2000.

RESULTS

One hundred twenty children with pelvic fractures were identified. Median age was 9 years (range, 1-16 years) and 66% (n = 80) were boys. Pedestrian-motor vehicle injury accounted for 68% (n = 82) of cases. Associated injuries were present in 78% (n = 94). Management of the pelvic fracture was nonoperative in 113 (94%). Thirty-two children (27%) required surgery for associated injuries. Complications during admission occurred in 28% (n = 34). Five children died as a result of their injuries. With a mean follow-up of 36 months (range, 7-156 months), 27% (n = 32) of children suffered an adverse outcome, including neurologic dysfunction and leg-length discrepancies.

CONCLUSION

The majority of pelvic fractures in children may be satisfactorily treated nonoperatively. Operative interventions were more frequently required for associated injuries. Long-term review is indicated because of delayed complications in children that are continuing to grow and develop.

Five percent, 7.5% or 10% hypertonic saline prevents delayed neuronal death in gerbils

PURPOSE

To clarify the appropriate concentration and dose of hypertonic saline solution (HSS) for preventing delayed neuronal death in the hippocampal CA1 subfield after transient forebrain ischemia in gerbils.

METHODS

Thirty gerbils were randomly assigned to five groups: physiological saline solution (PSS) group, ischemia/reperfusion treated with PSS 2 mL x kg(-1); 5% HSS group, treated with 5% HSS 2 mL x kg(-1); 7.5% HSS group, treated with 7.5% HSS 2 mL x kg(-1); 10% HSS group, treated with 10% HSS 2 mL x kg(-1); 20% HSS group, treated with 20% HSS 2 mL x kg(-1). Transient forebrain ischemia was induced by occluding the bilateral common carotid arteries for four minutes. Five days later, histopathological changes in the hippocampal area were examined, and the degenerative ratio of the pyramidal cells were measured according to the following formula: (number of degenerative pyramidal cells/total number of pyramidal cells per 1 mm of hippocampal CA1 subfield) x 100.

RESULTS

In PSS and 20% groups, neuronal cell damage was observed five days after ischemia. In the other three groups, these changes were not observed. The degenerative ratios of pyramidal cells were as follows; PSS group: 91.6 +/- 5.6%, 5% HSS group: 7.2 +/- 1.6%, 7.5% group: 8.3 +/- 1.4%, 10% HSS group: 6.2 +/- 1.1%, 20% HSS group: 85.8 +/- 8.7% (P < 0.05; PSS and 20% HSS vs three other groups).

CONCLUSION

This study demonstrates that 5, 7.5 or 10% HSS 2 mL x kg(-1) may prevent delayed neuronal death in the hippocampal CA1 subfield after cerebral ischemia/reperfusion in gerbils.

Cerebral resuscitation after traumatic brain injury and cardiopulmonary arrest in infants and children in the new millennium

As outlined in Figure 1, it is likely that a series of interventions beginning in the field and continuing through the emergency department, ICU, rehabilitation center, and possibly beyond, will be needed to optimize clinical outcome after severe TBI or asphyxial CA in infants and children. Despite the many differences between these two important pediatric insults, it is likely that many of the therapies targeting neuronal death, in either condition, will need to be administered early after the insult, possibly at the injury scene. Even cerebral swelling, a pathophysiologic derangement routinely treated in the PICU, almost certainly is better prevented rather than treated. Finally, this review includes, for one of the first times, a brief discussion of additional horizons in the management of patients with severe brain injury, namely, manipulation of the injured circuitry and stimulation of regeneration. Further research is needed to define better the pathobiology of these two important conditions at the bedside, to understand the optimal application of contemporary therapies, and to develop and apply novel therapies. The tools necessary to carry out these studies are materializing, although the obstacles are great. This difficult but important challenge awaits further investigation by clinician-scientists in pediatric neurointensive care.

Use of hypertonic saline solutions in treatment of cerebral edema and intracranial hypertension

OBJECTIVES

To review the literature on the use of hypertonic saline (HS) in treating cerebral edema and intracranial hypertension.

DATA SOURCES

Review of scientific and clinical literature retrieved from a computerized MEDLINE search from January 1965 through November 1999.

STUDY SELECTION

Pertinent literature is referenced, including clinical and laboratory investigations, to demonstrate principles and efficacy of treatment with HS in patients with intracranial space-occupying pathology.

DATA EXTRACTION

The literature was reviewed to summarize the mechanisms of action, efficacy, adverse effects, systemic effects, and comparisons with standard treatments in both clinical and laboratory settings.

DATA SYNTHESIS

HS has an osmotic effect on the brain because of its high tonicity and ability to effectively remain outside the bloodbrain barrier. Numerous animal studies have suggested that fluid resuscitation with HS bolus after hemorrhagic shock prevents the intracranial pressure (ICP) increase that follows resuscitation with standard fluids. There may be a minimal benefit in restoring cerebral blood flow, which is thought to be mitigated through local effects of HS on cerebral microvasculature. In animal models with cerebral injury, the maximum benefit is observed in animals with focal injury associated with vasogenic edema (cryogenic injury). The ICP reduction is seen for < or =2 hrs and may be maintained for longer periods by using a continuous infusion of HS. The ICP reduction is thought to be caused by a reduction in water content in areas of the brain with intact blood-brain barrier such as the nonlesioned hemisphere and cerebellum. Most comparisons with mannitol suggest almost equal efficacy in reducing ICP, but there is a suggestion that mannitol may have a longer duration of action. Human studies published to date reporting on the use of HS in treating cerebral edema and elevated ICP include case reports, case series, and small controlled trials. Results from studies directly comparing HS with standard treatment in regard to safety and efficacy are inconclusive. However, the low frequency of side effects and a definite reduction of ICP observed with use of HS in these studies are very promising. Systemic effects include transient volume expansion, natriuresis, hemodilution, immunomodulation, and improved pulmonary gas exchange. Adverse effects include electrolyte abnormalities, cardiac failure, bleeding diathesis, and phlebitis. Although unproven, a potential for central pontine myelinolysis and rebound intracranial hypertension exists with uncontrolled administration.

CONCLUSIONS

HS demonstrates a favorable effect on both systemic hemodynamics and intracranial pressure in both laboratory and clinical settings. Preliminary evidence supports the need for controlled clinical trials evaluating its use as resuscitative fluid in brain-injured patients with hemorrhagic shock, as therapy for intracranial hypertension resistant to standard therapy, as firstline therapy for intracranial hypertension in certain intracranial pathologies, as small volume fluid resuscitation during spinal shock, and as maintenance intravenous fluid in neurocritical care units.

Cerebral hemodynamic effects of 7.2% hypertonic saline in patients with head injury and raised intracranial pressure

The aim of the present study was to investigate the acute effects of 7.2% hypertonic saline (HS) on intracranial pressure (ICP), cerebral and systemic hemodynamics, serum sodium, and osmolality in 14 patients with moderate and severe traumatic brain injury (Glasgow Coma Scale < or =13) and raised ICP (>15 mm Hg) within the first 72 h postinjury. After CO2 reactivity and autoregulation were tested, each patient received a 15-min infusion of 7.2% HS (1,232 mEq/L, volume 1.5 mL/kg). ICP, serial hemodynamics, cerebral blood flow (CBF) estimated from cerebral arteriovenous oxygen content difference (AVDO2), and laboratory variables, including serum osmolality, electrolytes, urea, and creatinine were collected before infusion (T0) and at 5, 30, 60, and 120 min after (T5, T30, T60, T120). Urine output was measured 2 h before infusion and at T120. While CO2 reactivity was preserved in all patients, autoregulation was preserved in only four. ICP decreased to about 30% of base line (p = 0.0001) during the whole study period. During the first hour after infusion, cerebral perfusion pressure (p< or =0.04) and cardiac index (CI; p< or =0.01) increased, while systemic vascular resistance index fell (p< or =0.05). Heart rate increased (p< or =0.04) during the first 30 min. Pulmonary artery occlusion pressure (PAOP) increased (p = 0.004) at T5. There were no significant changes in mean arterial blood pressure (MABP), urine output, and estimated CBF. A significant positive correlation (r = 0.75; p = 0.02) between ICP and serum osmolality was found at T5. The administration of 7.2% HS in patients with traumatic brain injury significantly reduces ICP without significant changes in relative global CBF (expressed as 1/AVDO2), increases CI and transiently increases PAOP, without changing MABP and urine output. The correlation between changes in osmolality and ICP supports the hypothesis that HSS may in part decrease ICP by means of an osmotic mechanism.