Analysis of potential risks associated with 7.5% sodium chloride resuscitation of traumatic shock

Effectiveness of road safety interventions: An evidence and gap map

Background

Road Traffic injuries (RTI) are among the top ten leading causes of death in the world resulting in 1.35 million deaths every year, about 93% of which occur in low- and middle-income countries (LMICs). Despite several global resolutions to reduce traffic injuries, they have continued to grow in many countries. Many high-income countries have successfully reduced RTI by using a public health approach and implementing evidence-based interventions. As many LMICs develop their highway infrastructure, adopting a similar scientific approach towards road safety is crucial. The evidence also needs to be evaluated to assess external validity because measures that have worked in high-income countries may not translate equally well to other contexts. An evidence gap map for RTI is the first step towards understanding what evidence is available, from where, and the key gaps in knowledge.

Objectives

The objective of this evidence gap map (EGM) is to identify existing evidence from all effectiveness studies and systematic reviews related to road safety interventions. In addition, the EGM identifies gaps in evidence where new primary studies and systematic reviews could add value. This will help direct future research and discussions based on systematic evidence towards the approaches and interventions which are most effective in the road safety sector. This could enable the generation of evidence for informing policy at global, regional or national levels.

Search Methods

The EGM includes systematic reviews and impact evaluations assessing the effect of interventions for RTI reported in academic databases, organization websites, and grey literature sources. The studies were searched up to December 2019.

Selection Criteria

The interventions were divided into five broad categories: (a) human factors (e.g., enforcement or road user education), (b) road design, infrastructure and traffic control, (c) legal and institutional framework, (d) post-crash pre-hospital care, and (e) vehicle factors (except car design for occupant protection) and protective devices. Included studies reported two primary outcomes: fatal crashes and non-fatal injury crashes; and four intermediate outcomes: change in use of seat belts, change in use of helmets, change in speed, and change in alcohol/drug use. Studies were excluded if they did not report injury or fatality as one of the outcomes.

Data Collection and Analysis

The EGM is presented in the form of a matrix with two primary dimensions: interventions (rows) and outcomes (columns). Additional dimensions are country income groups, region, quality level for systematic reviews, type of study design used (e.g., case-control), type of road user studied (e.g., pedestrian, cyclists), age groups, and road type. The EGM is available online where the matrix of interventions and outcomes can be filtered by one or more dimensions. The webpage includes a bibliography of the selected studies and titles and abstracts available for preview. Quality appraisal for systematic reviews was conducted using a critical appraisal tool for systematic reviews, AMSTAR 2.

Main Results

The EGM identified 1859 studies of which 322 were systematic reviews, 7 were protocol studies and 1530 were impact evaluations. Some studies included more than one intervention, outcome, study method, or study region. The studies were distributed among intervention categories as: human factors (n = 771), road design, infrastructure and traffic control (n = 661), legal and institutional framework (n = 424), post-crash pre-hospital care (n = 118) and vehicle factors and protective devices (n = 111). Fatal crashes as outcomes were reported in 1414 records and non-fatal injury crashes in 1252 records. Among the four intermediate outcomes, speed was most commonly reported (n = 298) followed by alcohol (n = 206), use of seatbelts (n = 167), and use of helmets (n = 66). Ninety-six percent of the studies were reported from high-income countries (HIC), 4.5% from upper-middle-income countries, and only 1.4% from lower-middle and low-income countries. There were 25 systematic reviews of high quality, 4 of moderate quality, and 293 of low quality.

Authors' Conclusions

The EGM shows that the distribution of available road safety evidence is skewed across the world. A vast majority of the literature is from HICs. In contrast, only a small fraction of the literature reports on the many LMICs that are fast expanding their road infrastructure, experiencing rapid changes in traffic patterns, and witnessing growth in road injuries. This bias in literature explains why many interventions that are of high importance in the context of LMICs remain poorly studied. Besides, many interventions that have been tested only in HICs may not work equally effectively in LMICs. Another important finding was that a large majority of systematic reviews are of low quality. The scarcity of evidence on many important interventions and lack of good quality evidence-synthesis have significant implications for future road safety research and practice in LMICs. The EGM presented here will help identify priority areas for researchers, while directing practitioners and policy makers towards proven interventions.

Comparison of the effects of 7.2% hypertonic saline and 20% mannitol on electrolyte and acid-base variables in dogs with suspected intracranial hypertension

Background

Hyperosmolar agents frequently are used to decrease intracranial pressure but their effects on electrolyte and acid‐base variables have not been prospectively investigated.

Objectives

Compare duration and magnitude of changes in electrolyte and acid‐base variables after hyperosmolar treatment.

Animals

Twenty‐eight client‐owned dogs with intracranial hypertension caused by various pathologies.

Methods

Prospective, randomized, nonblinded, experimental cohort study. Fifteen dogs received a single dose (4 mL/kg) of 7.2% hypertonic saline (HTS), 13 dogs received 20% mannitol (MAN) 1 g/kg IV. Electrolyte and acid‐base variables were measured before (T₀), and 5 (T₅), 60 (T₆₀), and 120 (T₁₂₀) minutes after administration. Variables were compared between treatments and among time points within treatment groups.

Results

Mean plasma sodium and chloride concentrations were higher after HTS than MAN at T₅ (158 vs 141 mEq/L; 126 vs 109 mEq/L) and significant differences were maintained at all time points. After HTS, plasma sodium and chloride concentrations remained increased from T₀ at all time points. After MAN, plasma sodium and chloride concentrations decreased at T₅, but these changes were not maintained at T₆₀ and T₁₂₀. Plasma potassium concentration was lower at T₅ after HTS compared with T₀ (3.6 vs 3.9 mEq/L) and compared to MAN (3.6 vs 4.1 mEq/L). At T₆₀ and T₁₂₀, plasma ionized calcium concentration was lower after HTS than MAN (1.2 vs 1.3 mmol/L). No significant differences were found in acid‐base variables between treatments.

Conclusions and Clinical Importance

At the administered dose, dogs receiving HTS showed sustained increases in plasma sodium and chloride concentrations, whereas dogs receiving MAN showed transient decreases. Future studies should assess the effects of multiple doses of hyperosmolar agents on electrolyte and acid‐base variables.

Fluid resuscitation in critically ill patients: a systematic review and network meta-analysis

Objective

The aim of this study was to compare the effectiveness of different fluids on critically ill patients who need fluid resuscitation through a systematic review and network meta-analysis (NMA).

Data sources

Electronic databases were searched up to March 2018 for randomized controlled trials comparing the effectiveness of different fluids in critically ill patients. The primary outcome was mortality, and the secondary outcomes were the incident of acute kidney injury (AKI) and risk of receiving renal replacement therapy (RRT). A Bayesian NMA was conducted, and the quality of evidence contributing to each network estimate was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) Working Group criteria.

Results

We deemed 49 trials eligible, including 40,910 participants. The quality of evidence was rated as moderate in most comparisons. There was no significant difference among resuscitation fluids in mortality. NMA at the 9-node level showed the most effective fluid was balanced crystalloid (BC) (80.79%, the ranking of resuscitation fluid based on cumulative probability plots and surface under the cumulative ranking curves [SUCRAs]). NMA at the 10-node level showed that the most effective fluid was Plasma-Lyte (77.52%). Results of sensitivity analyses in mortality did not reveal any significant changes in the findings for primary outcomes. High-molecular-weight hetastarch (H-HES) was associated with an increased incidence of AKI when compared with gelatin (odds ratio [OR], 0.43; 95% credibility interval [CrI], 0.19–0.94), low-molecular-weight hetastarch (L-HES; OR, 0.50; 95% CrI, 0.30–0.87), BC (OR, 0.55; 95% CrI, 0.34–0.88), and normal saline (OR, 0.56; 95% CrI, 0.34–0.93). Meanwhile, H-HES was also associated with an increased risk of receiving RRT when compared with BC (OR, 0.51; 95% CrI, 0.27–0.93) and normal saline (OR, 0.52; 95% CrI, 0.24–0.96).

Conclusion

BCs, especially the Plasma-Lyte, are presumably the best choice for most critically ill patients who need fluid resuscitation. Meanwhile, the use of H-HES was associated with an increased incidence of AKI and risk of receiving RRT.

Registration

PROSPERO (CRD42017072728).

Colloids versus crystalloids for fluid resuscitation in critically ill people

BACKGROUND

Critically ill people may lose fluid because of serious conditions, infections (e.g. sepsis), trauma, or burns, and need additional fluids urgently to prevent dehydration or kidney failure. Colloid or crystalloid solutions may be used for this purpose. Crystalloids have small molecules, are cheap, easy to use, and provide immediate fluid resuscitation, but may increase oedema. Colloids have larger molecules, cost more, and may provide swifter volume expansion in the intravascular space, but may induce allergic reactions, blood clotting disorders, and kidney failure. This is an update of a Cochrane Review last published in 2013.

OBJECTIVES

To assess the effect of using colloids versus crystalloids in critically ill people requiring fluid volume replacement on mortality, need for blood transfusion or renal replacement therapy (RRT), and adverse events (specifically: allergic reactions, itching, rashes).

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase and two other databases on 23 February 2018. We also searched clinical trials registers.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs of critically ill people who required fluid volume replacement in hospital or emergency out-of-hospital settings. Participants had trauma, burns, or medical conditions such as sepsis. We excluded neonates, elective surgery and caesarean section. We compared a colloid (suspended in any crystalloid solution) versus a crystalloid (isotonic or hypertonic).

DATA COLLECTION AND ANALYSIS

Independently, two review authors assessed studies for inclusion, extracted data, assessed risk of bias, and synthesised findings. We assessed the certainty of evidence with GRADE.

MAIN RESULTS

We included 69 studies (65 RCTs, 4 quasi-RCTs) with 30,020 participants. Twenty-eight studied starch solutions, 20 dextrans, seven gelatins, and 22 albumin or fresh frozen plasma (FFP); each type of colloid was compared to crystalloids.Participants had a range of conditions typical of critical illness. Ten studies were in out-of-hospital settings. We noted risk of selection bias in some studies, and, as most studies were not prospectively registered, risk of selective outcome reporting. Fourteen studies included participants in the crystalloid group who received or may have received colloids, which might have influenced results.We compared four types of colloid (i.e. starches; dextrans; gelatins; and albumin or FFP) versus crystalloids.Starches versus crystalloidsWe found moderate-certainty evidence that there is probably little or no difference between using starches or crystalloids in mortality at: end of follow-up (risk ratio (RR) 0.97, 95% confidence interval (CI) 0.86 to 1.09; 11,177 participants; 24 studies); within 90 days (RR 1.01, 95% CI 0.90 to 1.14; 10,415 participants; 15 studies); or within 30 days (RR 0.99, 95% CI 0.90 to 1.09; 10,135 participants; 11 studies).We found moderate-certainty evidence that starches probably slightly increase the need for blood transfusion (RR 1.19, 95% CI 1.02 to 1.39; 1917 participants; 8 studies), and RRT (RR 1.30, 95% CI 1.14 to 1.48; 8527 participants; 9 studies). Very low-certainty evidence means we are uncertain whether either fluid affected adverse events: we found little or no difference in allergic reactions (RR 2.59, 95% CI 0.27 to 24.91; 7757 participants; 3 studies), fewer incidences of itching with crystalloids (RR 1.38, 95% CI 1.05 to 1.82; 6946 participants; 2 studies), and fewer incidences of rashes with crystalloids (RR 1.61, 95% CI 0.90 to 2.89; 7007 participants; 2 studies).Dextrans versus crystalloidsWe found moderate-certainty evidence that there is probably little or no difference between using dextrans or crystalloids in mortality at: end of follow-up (RR 0.99, 95% CI 0.88 to 1.11; 4736 participants; 19 studies); or within 90 days or 30 days (RR 0.99, 95% CI 0.87 to 1.12; 3353 participants; 10 studies). We are uncertain whether dextrans or crystalloids reduce the need for blood transfusion, as we found little or no difference in blood transfusions (RR 0.92, 95% CI 0.77 to 1.10; 1272 participants, 3 studies; very low-certainty evidence). We found little or no difference in allergic reactions (RR 6.00, 95% CI 0.25 to 144.93; 739 participants; 4 studies; very low-certainty evidence). No studies measured RRT.Gelatins versus crystalloidsWe found low-certainty evidence that there may be little or no difference between gelatins or crystalloids in mortality: at end of follow-up (RR 0.89, 95% CI 0.74 to 1.08; 1698 participants; 6 studies); within 90 days (RR 0.89, 95% CI 0.73 to 1.09; 1388 participants; 1 study); or within 30 days (RR 0.92, 95% CI 0.74 to 1.16; 1388 participants; 1 study). Evidence for blood transfusion was very low certainty (3 studies), with a low event rate or data not reported by intervention. Data for RRT were not reported separately for gelatins (1 study). We found little or no difference between groups in allergic reactions (very low-certainty evidence).Albumin or FFP versus crystalloidsWe found moderate-certainty evidence that there is probably little or no difference between using albumin or FFP or using crystalloids in mortality at: end of follow-up (RR 0.98, 95% CI 0.92 to 1.06; 13,047 participants; 20 studies); within 90 days (RR 0.98, 95% CI 0.92 to 1.04; 12,492 participants; 10 studies); or within 30 days (RR 0.99, 95% CI 0.93 to 1.06; 12,506 participants; 10 studies). We are uncertain whether either fluid type reduces need for blood transfusion (RR 1.31, 95% CI 0.95 to 1.80; 290 participants; 3 studies; very low-certainty evidence). Using albumin or FFP versus crystalloids may make little or no difference to the need for RRT (RR 1.11, 95% CI 0.96 to 1.27; 3028 participants; 2 studies; very low-certainty evidence), or in allergic reactions (RR 0.75, 95% CI 0.17 to 3.33; 2097 participants, 1 study; very low-certainty evidence).

AUTHORS' CONCLUSIONS

Using starches, dextrans, albumin or FFP (moderate-certainty evidence), or gelatins (low-certainty evidence), versus crystalloids probably makes little or no difference to mortality. Starches probably slightly increase the need for blood transfusion and RRT (moderate-certainty evidence), and albumin or FFP may make little or no difference to the need for renal replacement therapy (low-certainty evidence). Evidence for blood transfusions for dextrans, and albumin or FFP, is uncertain. Similarly, evidence for adverse events is uncertain. Certainty of evidence may improve with inclusion of three ongoing studies and seven studies awaiting classification, in future updates.

Administration of Hypertonic Solutions for Hemorrhagic Shock: A Systematic Review and Meta-analysis of Clinical Trials

BACKGROUND

Several clinical trials on hypertonic fluid administration have been completed, but the results have been inconclusive. The objective of this study is to summarize current evidence for treating hypovolemic patients with hypertonic solutions by performing a systematic review and meta-analysis.

METHODS

Major electronic databases were searched from inception through June 2014. We included only randomized controlled trials involving hemorrhagic shock patients treated with hypertonic solutions. After screening 570 trials, 12 were eligible for the final analysis. Pooled effect estimates were calculated with a random effect model.

RESULTS

The 12 studies included 6 trials comparing 7.5% hypertonic saline (HS) with 0.9% saline or Ringer's lactate solution and 11 trials comparing 7.5% hypertonic saline with dextran (HSD) with isotonic saline or Ringer's lactate. Overall, there were no statistically significant survival benefits for patients treated with HS (relative risk [RR], 0.96; 95% confidence interval [CI], 0.82-1.12) or HSD (RR, 0.92; 95% CI, 0.80-1.06). Treatment with hypertonic solutions was also not associated with increased complications (RR, 1.03; 95% CI, 0.78-1.36). Subgroup analysis on trauma patients in the prehospital or emergency department settings did not change these conclusions. There was no evidence of significant publication bias. Meta-regression analysis did not find any significant sources of heterogeneity.

CONCLUSIONS

Current evidence does not reveal increased mortality when the administration of isotonic solutions is compared to HS or HSD in trauma patients with hemorrhagic shock. HS or HSD may be a viable alternative resuscitation fluid in the prehospital setting. Further studies are needed to determine the optimum volume and regimen of intravenous fluids for the treatment of trauma patients.

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.

Immunomodulatory effect of hypertonic saline in hemorrhagic shock

Multiple organ dysfunction syndrome (MODS) and nosocomial infection following trauma-hemorrhage are among the most important causes of mortality in hemorrhagic shock patients. Dysregulation of the immune system plays a central role in MODS and a fluid having an immunomodulatory effect could be advantageous in hemorrhagic shock resuscitation. Hypertonic saline (HS) is widely used as a resuscitation fluid in trauma-hemorrhagic patients. Besides having beneficial effects on the hemodynamic parameters, HS has modulatory effects on various functions of immune cells such as degranulation, adhesion molecules and cytokines expression, as well as reactive oxygen species production. This article reviews clinical evidence for decreased organ failure and mortality in hemorrhagic shock patients resuscitated with HS. Despite promising results in animal models, results from pre-hospital and emergency department administration in human studies did not show improvement in survival, organ failure, or a reduction in nosocomial infection by HS resuscitation. Further post hoc analysis showed some benefit from HS resuscitation for severely-injured patients, those who received more than ten units of blood by transfusion, patients who underwent surgery, and victims of traumatic brain injury. Several reasons are suggested to explain the differences between clinical and animal models.

The prehospital management of traumatic brain injury

Traumatic brain injury (TBI) is an important cause of death and disability, particularly in younger populations. The prehospital evaluation and management of TBI is a vital link between insult and definitive care and can have dramatic implications for subsequent morbidity. Following a TBI the brain is at high risk for further ischemic injury, with prehospital interventions targeted at reducing this secondary injury while optimizing cerebral physiology. In the following chapter we discuss the prehospital assessment and management of the brain-injured patient. The initial evaluation and physical examination are discussed with a focus on interpretation of specific physical examination findings and interpretation of vital signs. We evaluate patient management strategies including indications for advanced airway management, oxygenation, ventilation, and fluid resuscitation, as well as prehospital strategies for the management of suspected or impending cerebral herniation including hyperventilation and brain-directed hyperosmolar therapy. Transport decisions including the role of triage models and trauma centers are discussed. Finally, future directions in the prehospital management of traumatic brain injury are explored.

Hypertonic saline in the traumatic hypovolemic shock: meta-analysis

BACKGROUND

A wealth of evidence from animal experiments has indicated that hypertonic saline (HS) maybe a better choice for fluid resuscitation in traumatic hypovolemic shock in comparison with conventional isotonic saline. However, the results of several clinical trials raised controversies on the superiority of fluid resuscitation with HS. This meta-analysis was performed to better understand the efficacy of HS in patients with traumatic hypovolemic shock comparing with isotonic saline.

MATERIALS AND METHODS

According to the search strategy, we searched the PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials, which was completed on October 2013. After literature searching, two investigators independently performed the literature screening, assessment of quality of the included trials, and data extraction. Disagreements were resolved by consensus or by a third investigator if needed. The outcomes included mortality, blood pressure, fluid requirement, and serum sodium.

RESULTS

Six randomized controlled trials were included in the meta-analysis. The pooled risk ratio for mortality at discharge was 0.96 (95% confidence interval [CI], 0.82-1.14), whereas the pooled mean difference for the change in systolic blood pressure from baseline and the level of serum sodium after infusion was 6.47 (95% CI, 1.31-11.63) and 7.94 (95% CI, 7.38-8.51), respectively. Current data were insufficient to evaluate the effect of HS on the fluid requirement for the resuscitation.

CONCLUSIONS

The present meta-analysis was unable to demonstrate a clinically important improvement in mortality after the HS administration. Moreover, we observed HS administration maybe accompanied with significant increase in blood pressure and serum sodium.

[The concept of small volume resuscitation for preclinical trauma management. Experiences in the Air Rescue Service]

BACKGROUND

Prompt hemorrhage control and adequate fluid resuscitation are the key components of early trauma care. However, the optimal resuscitation strategy remains controversial. In this context the small volume resuscitation (SVR) concept with hypertonic-hyperoncotic solutions is a new strategy.

PATIENTS AND METHODS

This was a retrospective study in the Helicopter Emergency Medical Service over a 5-year period. Included were all major trauma victims if they were candidates for SVR (initially 4 ml HyperHaes/kg body weight, followed by conventional fluid resuscitation with crystalloids and colloids). Demographic data, type and cause of injury and injury severity score (ISS) were recorded and the amount of fluid volume and the hemodynamic profile were analyzed. Negative side-effects as well as sodium chloride serum levels on hospital admission were recorded.

RESULTS

A total of 342 trauma victims (male 70.2%, mean age 39.0 ± 18.8 years, ISS 31.6 ± 16.9, ISS>16, 81.6%) underwent prehospital SVR. A blunt trauma mechanism was predominant (96.8%) and the leading cause of injury was motor vehicle accidents (61.5%) and motorcycle accidents (22.3%). Multiple trauma and polytrauma were noted in 87.4% of the cases. Predominant was traumatic brain injury (73.1%) as well as chest injury (73.1%) followed by limb injury (69.9%) and abdominal/pelvic trauma (45.0%). Within the whole study group in addition to 250 ml HyperHaes, mean volumes of 1214 ± 679 ml lactated Ringers and 1288 ± 954 ml hydroxethylstarch were infused during the prehospital treatment phase. There were no statistically significant differences in the amount of crystalloids and colloids infused regarding the subgroups multisystem trauma (ISS>16), severe traumatic brain injury (GCS<9) and entrapment trauma compared to the total study group. In patients with an initial systolic blood pressure (SBP) >80 mmHg significantly less colloids (1035 ± 659 ml vs. 1288 ± 954 ml, p<0.006) were infused, whereas in patients with an initial SBP ≤ 80 mmHg significantly more colloids were infused (1609 ± 1159 ml vs. 1288 ± 954 ml, p<0.002). There was a statistically significant increase in systolic as well as diastolic blood pressure at all times of blood pressure measurement during prehospital treatment after bolus infusion of HyperHaes within the whole study group. The same applies to the subgroups multisystem trauma, severe traumatic brain injury and entrapment trauma. Minor negative side-effects were observed in 4 cases (1.2%). The mean serum sodium chloride profile on hospital admission was 146.9 ± 5.0 mmol/l, the base excess (BE) was -5.7 ± 5.3 mmol/l) and the pH was 7.3 ± 0.1.

CONCLUSION

The concept of small volume resuscitation provides early and effective hemodynamic control. Clinical side-effects associated with bolus infusion of hypertonic-hyperoncotic solutions are rare.

ROC trials update on prehospital hypertonic saline resuscitation in the aftermath of the US-Canadian trials

The objectives of this review are to assess the current state of hypertonic saline as a prehospital resuscitation fluid in hypotensive trauma patients, particularly after the 3 major Resuscitation Outcomes Consortium trauma trials in the US and Canada were halted due to futility. Hemorrhage and traumatic brain injury are the leading causes of death in both military and civilian populations. Prehospital fluid resuscitation remains controversial in civilian trauma, but small-volume resuscitation with hypertonic fluids is of utility in military scenarios with prolonged or delayed evacuation times. A large body of pre-clinical and clinical literature has accumulated over the past 30 years on the hemodynamic and, most recently, the anti-inflammatory properties of hypertonic saline, alone or with dextran-70. This review assesses the current state of hypertonic fluid resuscitation in the aftermath of the failed Resuscitation Outcomes Consortium trials.

Updates in the management of the small animal patient with neurologic trauma

Neurologic trauma, encompassing traumatic brain injury (TBI) and acute spinal cord injury (SCI), is a cause of significant morbidity and mortality in veterinary patients. Acute SCIs occurring secondary to trauma are also common. Essential to the management of TBI and SCI is a thorough understanding of the pathophysiology of the primary and secondary injury that occurs following trauma. This article reviews the pathophysiology of this primary and secondary injury, as well as recommendations regarding clinical assessment, diagnostics, pharmacologic and nonpharmacologic therapy, and prognosis.

Colloids versus crystalloids for fluid resuscitation in critically ill patients

BACKGROUND

Colloid solutions are widely used in fluid resuscitation of critically ill patients. There are several choices of colloid, and there is ongoing debate about the relative effectiveness of colloids compared to crystalloid fluids.

OBJECTIVES

To assess the effects of colloids compared to crystalloids for fluid resuscitation in critically ill patients.

SEARCH METHODS

We searched the Cochrane Injuries Group Specialised Register (17 October 2012), the Cochrane Central Register of Controlled Trials (The Cochrane Library) (Issue 10, 2012), MEDLINE (Ovid) 1946 to October 2012, EMBASE (Ovid) 1980 to October 2012, ISI Web of Science: Science Citation Index Expanded (1970 to October 2012), ISI Web of Science: Conference Proceedings Citation Index-Science (1990 to October 2012), PubMed (October 2012), www.clinical trials.gov and www.controlled-trials.com. We also searched the bibliographies of relevant studies and review articles.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of colloids compared to crystalloids, in patients requiring volume replacement. We excluded cross-over trials and trials involving pregnant women and neonates.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and rated quality of allocation concealment. We analysed trials with a 'double-intervention', such as those comparing colloid in hypertonic crystalloid to isotonic crystalloid, separately. We stratified the analysis according to colloid type and quality of allocation concealment.

MAIN RESULTS

We identified 78 eligible trials; 70 of these presented mortality data.COLLOIDS COMPARED TO CRYSTALLOIDS: Albumin or plasma protein fraction - 24 trials reported data on mortality, including a total of 9920 patients. The pooled risk ratio (RR) from these trials was 1.01 (95% confidence interval (CI) 0.93 to 1.10). When we excluded the trial with poor-quality allocation concealment, pooled RR was 1.00 (95% CI 0.92 to 1.09). Hydroxyethyl starch - 25 trials compared hydroxyethyl starch with crystalloids and included 9147 patients. The pooled RR was 1.10 (95% CI 1.02 to 1.19). Modified gelatin - 11 trials compared modified gelatin with crystalloid and included 506 patients. The pooled RR was 0.91 (95% CI 0.49 to 1.72). (When the trials by Boldt et al were removed from the three preceding analyses, the results were unchanged.) Dextran - nine trials compared dextran with a crystalloid and included 834 patients. The pooled RR was 1.24 (95% CI 0.94 to 1.65). COLLOIDS IN HYPERTONIC CRYSTALLOID COMPARED TO ISOTONIC CRYSTALLOID: Nine trials compared dextran in hypertonic crystalloid with isotonic crystalloid, including 1985 randomised participants. Pooled RR for mortality was 0.91 (95% CI 0.71 to 1.06).

AUTHORS' CONCLUSIONS

There is no evidence from randomised controlled trials that resuscitation with colloids reduces the risk of death, compared to resuscitation with crystalloids, in patients with trauma, burns or following surgery. Furthermore, the use of hydroxyethyl starch might increase mortality. As colloids are not associated with an improvement in survival and are considerably more expensive than crystalloids, it is hard to see how their continued use in clinical practice can be justified.

Hyperosmolar therapy for intracranial hypertension

The use of hyperosmolar agents for intracranial hypertension was introduced in the early 20th century and remains a mainstay of therapy for patients with cerebral edema. Both animal and human studies have demonstrated the efficacy of two hyperosmolar agents, mannitol and hypertonic saline, in reducing intracranial pressure via volume redistribution, plasma expansion, rheologic modifications, and anti-inflammatory effects. However, because of physician and institutional variation in therapeutic practices, lack of standardized protocols for initiation and administration of therapy, patient heterogeneity, and a paucity of randomized controlled trials have yielded little class I evidence on which clinical decisions can be based, most current evidence regarding the use of hyperosmolar therapy is derived from retrospective analyses (class III) and case series (class IV). In this review, we summarize the available evidence regarding the use of hyperosmolar therapy with mannitol or hypertonic saline for the medical management of intracranial hypertension and present a comprehensive discussion of the evidence associated with various theoretical and practical concerns related to initiation, dosage, and monitoring of therapy.

Prehospital emergency trauma care and management

Prehospital care of the trauma patient is continuing to evolve; however, the principles of airway maintenance, hemorrhage control, and appropriate resuscitative maneuvers remain central to the role of the emergency medical care provider. Recent changes in the regulations for research in emergency settings will allow randomized trials to proceed to test new devices, drugs, and resuscitative strategies in the prehospital environment. The creation of prehospital research networks will provide the appropriate infrastructure to greatly facilitate the development of new protocols and the execution of large-scale randomized trials with the potential to change current prehospital practice.

Comparison of hypertonic saline versus normal saline on cytokine profile during CABG

Background and the purpose of the study

Blood contact with artificial surfaces of the extracorporeal circuit and ischemia-reperfusion injury in CABG with CPB, may lead to a systemic inflammatory response. Hypertonic saline have been recently investigated as a fluid in order to decrease inflammatory response and cytokines generation in patients undergo cardiac operations. Our purpose is to study the prophylactic effect of HS 5% infusion versus NS on serum IL-6 as an inflammatory & IL-10 as an anti-inflammatory biomarker in CABG patients.

Methods

The present study is a randomized double-blinded clinical trial. 40 patients undergoing CABG were randomized to receive HS 5% or NS before operation. Blood samples were obtained after receiving HS or NS, just before operation, 24 and 48 hours post-operatively. Plasma levels of IL-6 and IL-10 were measured by ELISA.

Results and major conclusion

Patients received HS had lower levels of IL-6 and higher level of IL-10 compared with NS group, however these differences were not statistically significant. Results of this study suggest that pre-treatment with small volume hypertonic saline 5% may have beneficial effects on inflammatory response following CABG operation.

Colloids versus crystalloids for fluid resuscitation in critically ill patients

BACKGROUND

Colloid solutions are widely used in fluid resuscitation of critically ill patients. There are several choices of colloid and there is ongoing debate about the relative effectiveness of colloids compared to crystalloid fluids.

OBJECTIVES

To assess the effects of colloids compared to crystalloids for fluid resuscitation in critically ill patients.

SEARCH METHODS

We searched the Cochrane Injuries Group Specialised Register (searched 16 March 2012), Cochrane Central Register of Controlled Trials 2011, issue 3 (The Cochrane Library), MEDLINE (Ovid) 1946 to March 2012, Embase (Ovid) 1980 to March 2012, ISI Web of Science: Science Citation Index Expanded (1970 to March 2012), ISI Web of Science: Conference Proceedings Citation Index-Science (1990 to March 2012), PubMed (searched 16 March 2012), www.clinical trials.gov and www.controlled-trials.com. We also searched the bibliographies of relevant studies and review articles.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of colloids compared to crystalloids, in patients requiring volume replacement. We excluded cross-over trials and trials in pregnant women and neonates.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data and rated quality of allocation concealment. We analysed trials with a 'double-intervention', such as those comparing colloid in hypertonic crystalloid to isotonic crystalloid, separately. We stratified the analysis according to colloid type and quality of allocation concealment.

MAIN RESULTS

We identified 74 eligible trials; 66 of these presented mortality data.Colloids compared to crystalloids Albumin or plasma protein fraction - 24 trials reported data on mortality, including a total of 9920 patients. The pooled relative risk (RR) from these trials was 1.01 (95% confidence interval (CI) 0.93 to 1.10). When we excluded the trial with poor quality allocation concealment, pooled RR was 1.00 (95% CI 0.92 to 1.09). Hydroxyethyl starch - 21 trials compared hydroxyethyl starch with crystalloids, n = 1385 patients. The pooled RR was 1.10 (95% CI 0.91 to 1.32). Modified gelatin - 11 trials compared modified gelatin with crystalloid, n = 506 patients. The pooled RR was 0.91 (95% CI 0.49 to 1.72). (When the trials by Boldt et al were removed from the three preceding analyses, the results were unchanged.) Dextran - nine trials compared dextran with a crystalloid, n = 834 patients. The pooled RR was 1.24 (95% CI 0.94 to 1.65).Colloids in hypertonic crystalloid compared to isotonic crystalloid Nine trials compared dextran in hypertonic crystalloid with isotonic crystalloid, including 1985 randomised participants. Pooled RR was 0.91 (95% CI 0.71 to 1.06).

AUTHORS' CONCLUSIONS

There is no evidence from RCTs that resuscitation with colloids reduces the risk of death, compared to resuscitation with crystalloids, in patients with trauma, burns or following surgery. As colloids are not associated with an improvement in survival, and as they are more expensive than crystalloids, it is hard to see how their continued use in these patients can be justified outside the context of RCTs.

Small-volume hypertonic saline/pentastarch improves ileal mucosal microcirculation in experimental peritonitis

We compared the effects of hypertonic saline 7.2%/6% hydroxyethyl starch (HSS-HES) and isotonic saline 0.9%/6% hydroxyethyl starch (ISS-HES) on ileal microcirculatory blood flow (MBF) at the initial phase of septic shock. Pigs were anesthetized and mechanically ventilated. Catheters were inserted into right atrium, pulmonary artery, carotid artery, and portal vein for hemodynamic measurements and for blood sampling. Ileal mucosal and muscularis MBF was continuously measured by laser Doppler flowmetry (LDF). Septic shock was obtained 240 min after induction of fecal peritonitis; then animals were randomized to receive 10 mL.kg(-1) during 10 min of either HSS-HES or ISS-HES. Systemic and microcirculatory blood flow as well as systemic metabolism were assessed. Fecal peritonitis promoted a hypodynamic septic shock, with significant reduction of mean arterial pressure (MAP) and cardiac index (CI). Ileal mucosal MBF (-34%) and ileal muscularis MBF (-54%) significantly diminished from baseline. Contrary to ISS-HES group, mucosal MBF significantly augmented after HSS-HES (+192% at min 150 post-shock) despite low blood pressure. There was weak correlation with CI (r(2)= 0.2, P=0.01) . Muscularis MBF didn't change. HSS-HES-treated animals had a significantly higher osmolarity and sodium concentration than ISS-HES group. Other variables did not change. Small-volume resuscitation with HSS-HES, but not ISS-HES, improved ileal microcirculatory impairment in experimental peritonitis model of septic shock even when MAP was low. This beneficial microcirculatory effect could be valuable in the management of early severe sepsis.

Circulatory consequences of reduced endogenous nitric oxide production during small-volume resuscitation

Hypertonic small-volume resuscitation transiently restores the cardiovascular function during various circulatory disturbances. Nitric oxide (NO) is an important mediator of flow-induced peripheral and central hemodynamic changes, and therefore, we hypothesized that a decreased endogenous NO production could influence the consequences and the effectiveness of hypertonic fluid therapy. The main goal of this study was to outline and compare the circulatory effects small volume hypertonic saline-dextran (HSD, 7.5% NaCl-10% dextran; 4 ml/kg iv) infusion with (n=7) or without (n=7) artificially diminished NO production in normovolemic anesthetized dogs. HSD administration significantly increased cardiac index (CI), coronary flow (CF) and myocardial contractility, and elevated plasma nitrite/nitrate (NOx) and endothelin-1 (ET-1) levels. However, the late (2 h) postinfusion period was characterized by significantly decreased myocardial NO synthase (NOS) and enhanced myeloperoxidase activities. Pre-treatment with the non-selective NOS inhibitor N-nitro-L-arginine (NNA, 4 mg/kg) immediately increased cardiac contractility, and the HSD-induced CI and CF elevations and the positive inotropy were absent. Additionally, plasma ET-1 levels increased and NOx levels were significantly decreased. In conclusion, our results demonstrate that HSD infusion leads to preponderant vasoconstriction when endogenous NO synthesis is diminished, and this could explain the loss of effectiveness of HSD resuscitation in NO-deficient states.

Randomized controlled trials affecting polytrauma care

Trauma remains the leading cause of death in the world in patients under 45 years of age. The evaluation, resuscitation, and appropriate management of polytraumatized patients are paramount to successful outcomes. The advance of evidence-based medicine has had a powerful and positive impact on trauma care, even though the nature of many traumatic injuries lends itself poorly to study in a randomized fashion. During the initial management of bleeding patients, hypotensive resuscitation prior to surgical control has found strong support in the literature, and its use has been adopted by many surgeons. Head injury is the most common cause of traumatic death, and while high-level evidence is limited, adherence to management guidelines is associated with improved outcomes. For abdominal trauma, the concept of damage control surgery, while popular, has never been put to the test in a randomized controlled trial. Numerous randomized trials in the field of critical care have affected the management of severely injured patients, including intensive insulin therapy and low tidal volume ventilation in patients with compromised respiratory function. Finally, a multidisciplinary approach to trauma care in designated trauma centers allows for improved outcomes in polytraumatized patients.

Out-of-hospital hypertonic resuscitation after traumatic hypovolemic shock: a randomized, placebo controlled trial

OBJECTIVE

To determine whether out-of-hospital administration of hypertonic fluids would improve survival after severe injury with hemorrhagic shock.

BACKGROUND

Hypertonic fluids have potential benefit in the resuscitation of severely injured patients because of rapid restoration of tissue perfusion, with a smaller volume, and modulation of the inflammatory response, to reduce subsequent organ injury.

METHODS

Multicenter, randomized, blinded clinical trial, May 2006 to August 2008, 114 emergency medical services agencies in North America within the Resuscitation Outcomes Consortium.

INCLUSION CRITERIA

injured patients, age ≥ 15 years with hypovolemic shock (systolic blood pressure ≤ 70 mm Hg or systolic blood pressure 71-90 mm Hg with heart rate ≥ 108 beats per minute). Initial resuscitation fluid, 250 mL of either 7.5% saline per 6% dextran 70 (hypertonic saline/dextran, HSD), 7.5% saline (hypertonic saline, HS), or 0.9% saline (normal saline, NS) administered by out-of-hospital providers. Primary outcome was 28-day survival. On the recommendation of the data and safety monitoring board, the study was stopped early (23% of proposed sample size) for futility and potential safety concern.

RESULTS

 : A total of 853 treated patients were enrolled, among whom 62% were with blunt trauma, 38% with penetrating. There was no difference in 28-day survival-HSD: 74.5% (0.1; 95% confidence interval [CI], -7.5 to 7.8); HS: 73.0% (-1.4; 95% CI, -8.7-6.0); and NS: 74.4%, P = 0.91. There was a higher mortality for the postrandomization subgroup of patients who did not receive blood transfusions in the first 24 hours, who received hypertonic fluids compared to NS [28-day mortality-HSD: 10% (5.2; 95% CI, 0.4-10.1); HS: 12.2% (7.4; 95% CI, 2.5-12.2); and NS: 4.8%, P < 0.01].

CONCLUSION

Among injured patients with hypovolemic shock, initial resuscitation fluid treatment with either HS or HSD compared with NS, did not result in superior 28-day survival. However, interpretation of these findings is limited by the early stopping of the trial.

CLINICAL TRIAL REGISTRATION

Clinical Trials.gov, NCT00316017.

Colloids versus crystalloids for fluid resuscitation in critically ill patients

BACKGROUND

Colloid solutions are widely used in fluid resuscitation of critically ill patients. There are several choices of colloid and there is ongoing debate about the relative effectiveness of colloids compared to crystalloid fluids.

OBJECTIVES

To assess the effects of colloids compared to crystalloids for fluid resuscitation in critically ill patients.

SEARCH STRATEGY

We searched the Cochrane Injuries Group Specialised Register, CENTRAL (The Cochrane Library 2008, Issue 3), MEDLINE, EMBASE, ISI Web of Science: Science Citation Index Expanded (SCI-EXPANDED), ISI Web of Science: Conference Proceedings Citation Index-Science (CPCI-S), and The Controlled Trials metaRegister (www.controlled-trials.com). Reference lists of relevant studies and review articles were searched for further trials. The searches were last updated in September 2008.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of colloids compared to crystalloids, in patients requiring volume replacement. We excluded cross-over trials and trials in pregnant women and neonates.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data and rated quality of allocation concealment. We analysed trials with a 'double-intervention', such as those comparing colloid in hypertonic crystalloid to isotonic crystalloid, separately. We stratified the analysis according to colloid type and quality of allocation concealment.

MAIN RESULTS

We identified 65 eligible trials; 56 of these presented mortality data.Colloids compared to crystalloidsAlbumin or plasma protein fraction - 23 trials reported data on mortality, including a total of 7754 patients. The pooled relative risk (RR) from these trials was 1.01 (95% confidence interval (95% CI) 0.92 to 1.10). When we excluded the trial with poor quality allocation concealment, pooled RR was 1.00 (95% CI 0.91 to 1.09). Hydroxyethyl starch - 17 trials compared hydroxyethyl starch with crystalloids, n = 1172 patients. The pooled RR was 1.18 (95% CI 0.96 to 1.44). Modified gelatin - 11 trials compared modified gelatin with crystalloid, n = 506 patients. The pooled RR was 0.91 (95% CI 0.49 to 1.72). (When the trials by Boldt et al were removed from the three preceding analyses, the results were unchanged.) Dextran - nine trials compared dextran with a crystalloid, n = 834 patients. The pooled RR was 1.24 (95% CI 0.94 to 1.65).Colloids in hypertonic crystalloid compared to isotonic crystalloidEight trials compared dextran in hypertonic crystalloid with isotonic crystalloid, including 1283 randomised participants. Pooled RR was 0.88 (95% CI 0.74 to 1.05).

AUTHORS' CONCLUSIONS

There is no evidence from RCTs that resuscitation with colloids reduces the risk of death, compared to resuscitation with crystalloids, in patients with trauma, burns or following surgery. As colloids are not associated with an improvement in survival, and as they are more expensive than crystalloids, it is hard to see how their continued use in these patients can be justified outside the context of RCTs.

Use of hypertonic saline injection in trauma

PURPOSE

The use of hypertonic saline injection in trauma patients is discussed.

SUMMARY

Patients with hemorrhage, burns, and traumatic brain injury (TBI) may develop hypovolemic shock and require resuscitation. Compared with conventional isotonic crystalloids, hypertonic saline has several advantages, including hemodynamic, immune-modulating, and antiinflammatory effects, for use in trauma patients for resuscitation. In addition, hypertonic saline is also used in patients with TBI to reduce intracranial pressure (ICP). Overall, studies have not shown a difference in mortality or other clinically important outcomes with the use of hypertonic saline for resuscitation in trauma patients; however, most of these studies were not adequately powered to show significant differences. A recent Cochrane review concluded that there is no evidence that hypertonic crystalloids are better than isotonic or near-isotonic crystalloids for fluid resuscitation in trauma patients. Two recent trials that were adequately powered to investigate a mortality endpoint were halted for futility. A few small randomized controlled studies found that hypertonic saline was more effective than mannitol as a hyperosmolar agent for ICP reduction. Recent guidelines from the American Burn Association have suggested that hypertonic saline may be used for burn shock resuscitation by experienced providers with close monitoring to avoid excessive hypernatremia. One of the main concerns with the use of hypertonic saline is its potential to cause central pontine myelinolysis due to a rapid increase in serum sodium levels.

CONCLUSION

There is no evidence that hypertonic saline provides any additional benefit over isotonic crystalloid solutions for trauma resuscitation. Hypertonic saline may be more effective than mannitol at reducing ICP in patients with TBI.

Current concepts in resuscitation

Early recognition and differentiation of shock, as well as goal-directed resuscitation, are fundamental principles in the care of the critically ill or injured patient. Substantial progress has been made over the last decade in the understanding of both shock and resuscitation. Specific areas of advancement, particularly pertaining to hemorrhagic shock, include a heightened appreciation of dynamic measurements of preload responsiveness (e.g., respiratory-induced pulse pressure and venous diameter variability), an improved awareness of the detrimental effects of blood product transfusion, and better recognition of the complications of overzealous volume expansion. However, several areas of controversy remain regarding the optimal resuscitation strategy. These include the optimal targets for perfusion pressure and oxygen delivery, endpoints of resuscitation, resuscitative fluid, and transfusion strategies for packed red blood cells and blood products. This article reviews the diagnosis and differentiation of shock, measurements of tissue perfusion, current evidence regarding various resuscitative techniques, and complications of resuscitation.

The role of pre-hospital blood gas analysis in trauma resuscitation

Background

To assess, whether arterial blood gas measurements during trauma patient's pre-hospital shock resuscitation yield useful information on haemodynamic response to fluid resuscitation by comparing haemodynamic and blood gas variables in patients undergoing two different fluid resuscitation regimens.

Methods

In a prospective randomised study of 37 trauma patients at risk for severe hypovolaemia, arterial blood gas values were analyzed at the accident site and on admission to hospital. Patients were randomised to receive either conventional fluid therapy or 300 ml of hypertonic saline. The groups were compared for demographic, injury severity, physiological and outcome variables.

Results

37 patients were included. Mean (SD) Revised Trauma Score (RTS) was 7.3427 (0.98) and Injury Severity Score (ISS) 15.1 (11.7). Seventeen (46%) patients received hypertonic fluid resuscitation and 20 (54%) received conventional fluid therapy, with no significant differences between the groups concerning demographic data or outcome. Base excess (BE) values decreased significantly more within the hypertonic saline (HS) group compared to the conventional fluid therapy group (mean BE difference -2.1 mmol/l vs. -0.5 mmol/l, p = 0.003). The pH values on admission were significantly lower within the HS group (mean 7.31 vs. 7.40, p = 0.000). Haemoglobin levels were in both groups lower on admission compared with accident site. Lactate levels on admission did not differ significantly between the groups.

Conclusion

Pre-hospital use of small-volume resuscitation led to significantly greater decrease of BE and pH values. A portable blood gas analyzer was found to be a useful tool in pre-hospital monitoring for trauma resuscitation.

Blood loss and transcapillary refill in uncontrolled treated hemorrhage in dogs

OBJECTIVE

This study evaluated retroperitoneal hematomas produced by bilateral injury of iliac arteries (uncontrolled hemorrhage), blood volume loss, transcapillary refill, the effects of volume replacement on retroperitoneal bleeding and the hemodynamic changes with and without treatment.

METHODS

Initial blood volume was determined with Tc(99m)-labelled red cells, and bleeding was evaluated by means of a portable scintillation camera positioned over the abdomen. Previously splenectomized mongrel dogs (16.8 +/- 2.2 kg) were submitted to hemorrhage for 30 minutes and randomized into three groups: I - no treatment (n=7); II - treatment with 32 mL/kg of Lactated Ringer's for three to five minutes (n=7); and III - treatment with 4 mL/kg of 7.5% NaCl plus 6.0% dextran 70 for three to five minutes (n=7). They were studied for an additional 45 minutes.

RESULTS

Volume replacement produced transitory recovery in hemodynamic variables, including mean pulmonary artery pressure, pulmonary capillary wedge pressure and cardiac index, with significant increase in dogs treated with 32 mL/kg of Lactated Ringer's and 7.5% NaCl plus 6.0% dextran 70 (p<0.001, against no treatment), along with a decrease (p<0.001) in the systemic vascular resistance index. Groups II and III had significant initial decreases in hematocrit and hemoglobin. The treated dogs (groups II and III) presented rebleeding, which was greater during treatment with 32 mL/kg of Lactated Ringer's (group II).

CONCLUSIONS

Despite the rebleeding observed in treated groups, the utilization of hypertonic saline solution with dextran proved to be effective in the initial reanimation, producing evident transcapillary refill, while the Lactated Ringer's solution produced capillary extravasation and was ineffective in the initial volume replacement in this model of uncontrolled hemorrhage.

Guidelines for prehospital fluid resuscitation in the injured patient

Although the need and benefit of prehospital interventions has been controversial for quite some time, an increasing amount of evidence has stirred both sides into more frequent debate. Proponents of the traditional "scoop-and-run" technique argue that this approach allows a more timely transfer to definitive care facilities and limits unnecessary (and potentially harmful) procedures. However, advocates of the "stay-and-play" method point to improvement in survival to reach the hospital and better neurologic outcomes after brain injury. Given the lack of consensus, the Eastern Association for the Surgery of Trauma convened a Practice Management Guideline committee to answer the following questions regarding prehospital resuscitation: (1) should injured patients have vascular access attempted in the prehospital setting? (2) if so, what location is preferred for access? (3) if access is achieved, should intravenous fluids be administered? (4) if fluids are to be administered, which solution is preferred? and (5) if fluids are to be administered, what volume and rate should be infused?

Hypertonic saline in critical care: a review of the literature and guidelines for use in hypotensive states and raised intracranial pressure

Hypertonic saline has been in clinical use for many decades. Its osmotic and volume-expanding properties make it theoretically useful for a number of indications in critical care. This literature review evaluates the use of hypertonic saline in critical care. The putative mechanism of action is presented, followed by a narrative review of its clinical usefulness in critical care. The review was conducted using the Scottish Intercollegiate Guidelines Network method for the review of cohort studies, randomised-controlled trials and meta-analyses. The review focuses specifically on blood pressure restoration and outcome benefit in both haemorrhagic and non-haemorrhagic shock, and the management of raised intracranial pressure. Issues of clinical improvement and outcome benefit are addressed. Hypertonic saline solutions are effective for blood pressure restoration in haemorrhagic, but not other, types of shock. There is no survival benefit with the use of hypertonic saline solutions in shock. Hypertonic saline solutions are effective at reducing intracranial pressure in conditions causing acute intracranial hypertension. There is no survival or outcome benefit with the use of hypertonic saline solutions for raised intracranial pressure. Recommendations for clinical use and future directions of clinical research are presented.

Management of traumatic brain injury: first link in chain of survival

Traumatic brain injury is a significant cause of morbidity and mortality. The prehospital care of the patient with a traumatic brain injury is critical to maximizing the chances for a good outcome. Prehospital management of the traumatic brain injury patient is directed toward preventing and limiting secondary brain injury while facilitating rapid transport to an appropriate facility capable of providing definitive neurocritical care. Key points in management include the assessment of oxygenation, blood pressure, and mental status (as measured with the Glasgow Coma Scale) and the pupillary examination. Treatment strategies are directed toward maintaining adequate oxygenation and perfusion and treating herniation. Judicious use of temporary hyperventilation and hypertonic saline are considerations. This review provides the most recent evidence regarding the treatment of traumatic brain injury in the prehospital setting and introduces areas in need of future research.

Review article: hypertonic saline use in the emergency department

Hypertonic saline (HS) is being increasingly used for the management of a variety of conditions, most notably raised intracranial pressure. This article reviews the available evidence on HS solutions as they relate to emergency medicine, and develops a set of recommendations for its use. To conclude, HS is recommended as an alternative to mannitol for treating raised intracranial pressure in traumatic brain injury. HS is also recommended for treating severe and symptomatic hyponatremia, and is worth considering for both recalcitrant tricyclic antidepressant toxicity and for cerebral oedema complicating paediatric diabetic ketoacidosis. HS is not recommended for hypovolaemic resuscitation.

Colloids versus crystalloids for fluid resuscitation in critically ill patients

BACKGROUND

Colloid solutions are widely used in fluid resuscitation of critically ill patients. There are several choices of colloid and there is ongoing debate about the relative effectiveness of colloids compared to crystalloid fluids.

OBJECTIVES

To assess the effects of colloids compared to crystalloids for fluid resuscitation in critically ill patients.

SEARCH STRATEGY

We searched the Cochrane Injuries Group's specialised register, CENTRAL, MEDLINE, EMBASE, the National Research Register, Web of Science and MetaRegister. Bibliographies of trials and review articles retrieved were searched. The searches were last updated in December 2006.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of colloids compared to crystalloids, in patients requiring volume replacement. Cross-over trials and trials in pregnant women and neonates were excluded.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data and rated quality of allocation concealment. Trials with a 'double-intervention', such as those comparing colloid in hypertonic crystalloid to isotonic crystalloid, were analysed separately. The analysis was stratified according to colloid type and quality of allocation concealment.

MAIN RESULTS

We identified 63 eligible trials, 55 of these presented mortality data. COLLOIDS COMPARED TO CRYSTALLOIDS: Albumin or plasma protein fraction - 23 trials reported data on mortality, including a total of 7,754 patients. The pooled relative risk (RR) from these trials was 1.01 (95% confidence interval [95% CI] 0.92 to 1.10). When the trial with poor quality allocation concealment was excluded, pooled RR was 1.00 (95% CI 0.91 to 1.09). Hydroxyethyl starch - 16 trials compared hydroxyethyl starch with crystalloids, n = 637 patients. The pooled RR was 1.05 (95% CI 0.63 to 1.75). Modified gelatin - 11 trials compared modified gelatin with crystalloid, n = 506 patients. The pooled RR was 0.91 (95% CI 0.49 to 1.72). Dextran - nine trials compared dextran with a crystalloid, n = 834 patients. The pooled RR was 1.24 (95% CI 0.94 to 1.65). COLLOIDS IN HYPERTONIC CRYSTALLOID COMPARED TO ISOTONIC CRYSTALLOID: Eight trials compared dextran in hypertonic crystalloid with isotonic crystalloid, including 1,283 randomised participants. Pooled RR was 0.88 (95% CI 0.74 to 1.05).

AUTHORS' CONCLUSIONS

There is no evidence from RCTs that resuscitation with colloids reduces the risk of death, compared to resuscitation with crystalloids, in patients with trauma, burns or following surgery. As colloids are not associated with an improvement in survival, and as they are more expensive than crystalloids, it is hard to see how their continued use in these patients can be justified outside the context of RCTs.

Hypertonic saline: a clinical review

Literature suggest that hypertonic saline (HTS) solution with sodium chloride concentration greater than the physiologic 0.9% can be useful in controlling elevated intracranial pressure (ICP) and as a resuscitative agent in multiple settings including traumatic brain injury (TBI). In this review, we discuss HTS mechanisms of action, adverse effects, and current clinical studies. Studies show that HTS administered during the resuscitation of patients with a TBI improves neurological outcome. HTS also has positive effects on elevated ICP from multiple etiologies, and for shock resuscitation. However, a prospective randomized Australian study using an aggressive resuscitation protocol in trauma patients showed no difference in amount of fluids administered during prehospital resuscitation, and no differences in ICP control or neurological outcome. The role of HTS in prehospital resuscitation is yet to be determined. The most important factor in improving outcomes may be prevention of hypotension and preservation of cerebral blood flow. In regards to control of elevated ICP during the inpatient course, HTS appears safe and effective. Although clinicians currently use HTS with some success, significant questions remain as to the dose and manner of HTS infusion. Direct protocol comparisons should be performed to improve and standardize patient care.

Traumatic brain injury: assessment, resuscitation and early management

This review examines the evidence base for the early management of head-injured patients. Traumatic brain injury (TBI) is common, carries a high morbidity and mortality, and has no specific treatment. The pathology of head injury is increasingly well understood. Mechanical forces result in shearing and compression of neuronal and vascular tissue at the time of impact. A series of pathological events may then ensue leading to further brain injury. This secondary injury may be amenable to intervention and is worsened by secondary physiological insults. Various risk factors for poor outcome after TBI have been identified. Most of these are fixed at the time of injury such as age, gender, mechanism of injury, and presenting signs (Glasgow Coma Scale and pupillary signs), but some such as hypotension and hypoxia are potential areas for medical intervention. There is very little evidence positively in favour of any treatments or packages of early care; however, prompt, specialist neurocritical care is associated with improved outcome. Various drugs that target specific pathways in the pathophysiology of brain injury have been the subject of animal and human research, but, to date, none has been proved to be successful in improving outcome.

Use of Hypertonic 7.5% Sodium Chloride (NaCl) Solution in Patients with Traumatic Brain Injuries Trauma: Antibiotics in Open Fractures: Sedation Update: Time for a Change?

This feature examines the impact of pharmacologic interventions on the treatment of the critically ill patient — an area of health care that has become increasingly complex. Recent advances in drug therapy (including evolving and controversial data) for adult intensive-care-unit patients will be reviewed and assessed in terms of clinical, humanistic, and economic outcomes. Direct questions or comments to Sandra Kane-Gill, PharmD, MSc, at kanesl@upmc.edu .

The effects of 10% hypertonic saline, 0.9% saline and hydroxy ethyl starch infusions on hydro-electrolyte status and adrenal function in healthy conscious dogs

The purpose of this study was to investigate the influence of different saline and colloid solutions on adrenal steroid secretion in dogs. Six healthy male Beagles underwent three infusion cycles: 10 min infusion of 30 ml/kg of NaCl 0.9%, 5 ml/kg of hydroxy ethyl starch, or 5 ml/kg of NaCl 10%. Plasma osmolality, hematocrit, total solids, cortisol and aldosterone levels were measured at 0, 5, 15, 30, 60, 120, 180 and 240 min after beginning infusion. Plasma ACTH levels were measured at 0, 15 and 240 min. An identical timing of sampling was applied during a control session omitting the fluid infusion. Osmolality, sodium, chloride and cortisol levels were found to be significantly higher with hypertonic saline solute compared to control. All fluid infusions lead to lowered plasma potassium, hematocrit, total solids and aldosterone values. ACTH concentrations did not show significant changes with any of the infusion cycles. The increase in cortisol levels suggests that hypertonic saline infusion could be interesting in critical care resuscitation, particularly in patients who are suffering from relative adrenal insufficiency.

Hypertonic-hyperoncotic solutions improve cardiac function in children after open-heart surgery

OBJECTIVES

Hypertonic-hyperoncotic solutions are used for the improvement of micro- and macrocirculation in various types of shock. In pediatric intensive care medicine, controlled, randomized studies with hypertonic-hyperoncotic solutions are lacking. Hypertonic-hyperoncotic solutions may improve cardiac function in children. The primary objective of this controlled, randomized, blinded study was to evaluate the hemodynamic effects and safety of hypertonic-hyperoncotic solution infusions in children shortly after open-heart surgery for congenital cardiac disease. The secondary objective was to determine whether the administration of hypertonic-hyperoncotic solutions could be a potential and effective therapeutic option for preventing a probable capillary leakage syndrome that frequently occurs in children after open-heart surgery.

METHODS

The children were randomly assigned to 2 groups of 25. The hypertonic-hyperoncotic solution group received Poly-(O-2)-hydroxyethyl-starch 60.0 g, with molecular weight of 200 kDa, Na+ 1232 mmol/L and osmolality of 2464 mOsmol/L (7.2% sodium chloride with 6% hydroxyethyl-starch 200 kDa). The isotonic saline solution group received isotonic saline solution (0.9% sodium chloride). Atrial and ventricular septal defects were corrected using a homograft patch. Monitoring consisted of an arterial, a central venous, and a thermodilution catheter (PULSIOCATH). Cardiac index, extravascular lung water index, stroke volume index, mean arterial blood pressure, and systemic vascular resistance index were measured (Pulse Contour Cardiac Output technique). Immediately after surgery, patients were loaded either with hypertonic-hyperoncotic solution or with isotonic saline solution (4 mL/kg). Blood samples (sodium concentration, osmolality, thrombocyte count, fibrinogen, and arterial blood gases) were drawn directly before; immediately after; 15 minutes after; and, 1, 4, 12, and 24 hours after the end of volume loading. Hemodynamic parameters were registered at the same time. The total amount of dobutamine required was documented, as well as the 24- and 48-hour fluid balances.

RESULTS

In the hypertonic-hyperoncotic solution group, cardiac index was 3.6 +/- 0.26 L/min per m2 before volume administration and increased to 5.96 +/- 0.27 after the administration of the study solution (64%). Fifteen and 60 minutes after administration, the cardiac index remained significantly elevated (5.55 +/- 0.29 L/min per m2 and 4.65 +/- 0.18 L/min per m2, respectively) and returned to preadministration values after 4 hours. In the isotonic saline solution group, the cardiac index did not change during the entire observation period (3.39 +/- 0.21 before and 3.65 +/- 0.23 L/min per m2 after isotonic saline solution). The systemic vascular resistance index decreased in the hypertonic-hyperoncotic solution group after administration from 1396 +/- 112 to 868 +/- 63 dyn/sec per cm(-5)/m2. The decrease of systemic vascular resistance index in the hypertonic-hyperoncotic solution group was transiently significant within 60 minutes after administration but stayed lower than before volume load (999 +/- 70 dyn/sec per cm-(5)/m2). In the isotonic saline solution group, we found no statistically relevant change in systemic vascular resistance index. Stroke volume index significantly increased after hypertonic-hyperoncotic solution infusion (53.9 +/- 3.0 mL/m2 directly after, 48.8 +/- 2.46 mL/m2 15 minutes after, and 41.4 +/- 2.2 mL/m2 60 minutes after) when compared with stroke volume index before administration (32.4 +/- 2.6 mL/m2). In the hypertonic-hyperoncotic solution group, an increase in mean arterial blood pressure remained transiently significant within 60 minutes after administration when compared with the isotonic saline solution group, in which the mean arterial blood pressure remained unchanged. Both central venous pressure and heart rate were unchanged during the whole time of observation in both groups. In the hypertonic-hyperoncotic solution group, extravascular lung water index decreased from 10.6 +/- 1.2 to 5.6 +/- 1.2 mL/kg and remained significantly decreased 15 minutes after (6.5 +/- 1.2 mL/kg) when compared with before volume administration. In the isotonic saline solution group, extravascular lung water index increased from 12.3 +/- 1.1 mL/kg to 18.1 +/- 1.7 mL/kg directly after administration and remained elevated for 60 minutes after volume loading (15.6 +/- 1.5 mL/kg). In all patients, no hypoxia (Pa(O2)<60 mm Hg) or hypercapnia (Pa(CO2) >60 mm Hg) was observed. Arterial blood gas analysis showed pH and base excess within physiologic range, and this did not change throughout the whole period of observation. After infusion of hypertonic-hyperoncotic solution, sodium concentration increased from 139.2 +/- 0.7 to 147.5 +/- 0.7 mmol/L. The maximum sodium concentration was 153 mmol/L, measured immediately after hypertonic-hyperoncotic solution in 1 patient. The total amount of fluid infused was similar in both groups. The postoperative need for infused dobutamine in the patients in the hypertonic-hyperoncotic solution group was decreased compared with the isotonic saline solution group (46.9 +/- 8.8 microg/kg vs 308.2 +/- 46.6 microg/kg). No patient presented with severe bleeding. Short- and long-term cardiac and neurologic outcome was not reduced and all patients left the hospital in a clinically sufficient state.

DISCUSSION

This study demonstrates a profound increase of cardiac index after the administration of hypertonic-hyperoncotic solution in children after uncomplicated open-heart surgery, suggesting a positive inotropic effect. The total amount of catecholamine was lower, assuming that hypertonic-hyperoncotic solution reduces the need for positive inotropic support. The observed positive cardiac effect of hypertonic-hyperoncotic solution may even be intensified by the decreased afterload (decreased systemic vascular resistance index). According to the Frank-Starling relation, an effective tool in the treatment of low cardiac output are an elevated preload while afterload is diminished. Therefore, we postulate that hypertonic-hyperoncotic solution may be helpful in preventing or attenuating low cardiac output failure in childhood. Capillary leakage syndrome also is a frequent problem after cardiopulmonary bypass. For quantification of edema formation, extravascular lung water index measurement is a useful tool. Using this approach, we provided evidence that the infusion of hypertonic-hyperoncotic solution is transiently able to reduce extravascular lung water index. This reduction was transient but might prevent the triggering of a clinically relevant capillary leakage syndrome. This is in line with in vitro studies demonstrating that hypertonic-hyperoncotic solution improves microcirculation by reducing vascular permeability. The single administration of hypertonic-hyperoncotic solution infusion was safe, and no adverse effects, such as hemostatic disturbances, were observed.

CONCLUSIONS

A single infusion of hypertonic-hyperoncotic saline solution after cardiac surgery is safe despite the hypertonicity and the colloid component of the hypertonic-hyperoncotic saline solution. In children after cardiopulmonary bypass surgery, the administration of hypertonic-hyperoncotic saline solution increased cardiac index by elevating stroke volume index in combination with a lowered systemic vascular resistance index. Extravascular lung water index transiently decreased, suggesting that hypertonic-hyperoncotic saline solution effectively counteracts the capillary leakage that often occurs after cardiac surgery in children. Additional investigations might elucidate whether the temporary effects of hypertonic-hyperoncotic saline solution are beneficial in the treatment of severe capillary leakage after complicated cardiac surgery. It has to be shown that hypertonic-hyperoncotic saline solution is a long-lasting, effective treatment strategy for low cardiac output failure in children that is caused by sepsis, multiorgan failure, and endothelial edema. We have provided evidence to pediatric intensive care clinicians that the single administration of hypertonic-hyperoncotic saline solution might be a useful and safe treatment in the amelioration of contractility, inotropy, and the possible treatment of early-onset capillary leakage.

The Use of Hypertonic Saline for Treating Intracranial Hypertension After Traumatic Brain Injury

The past decade has witnessed a resurgence of interest in the use of hypertonic saline for low-volume resuscitation after trauma. Preliminary studies suggested that benefits are limited to a subgroup of trauma patients with brain injury, but a recent study of prehospital administration of hypertonic saline to patients with traumatic brain injury failed to confirm a benefit. Animal and human studies have demonstrated that hypertonic saline has clinically desirable physiological effects on cerebral blood flow, intracranial pressure, and inflammatory responses in models of neurotrauma. There are few clinical studies in traumatic brain injury with patient survival as an end point. In this review, we examined the experimental and clinical knowledge of hypertonic saline as an osmotherapeutic agent in neurotrauma.

Hypertonic saline resuscitation after mesenteric ischemia/reperfusion induces ileal apoptosis

BACKGROUND

We have previously demonstrated that hypertonic saline (HS) resuscitation decreased inflammation and mucosal injury after mesenteric ischemia/reperfusion (I/R). In contrast to I/R cell necrosis, apoptosis provides controlled cell death that minimizes inflammation. We therefore hypothesized that HS resuscitation after mesenteric I/R would induce apoptosis and decrease mucosal injury.

METHODS

Rats underwent 60 minutes of superior mesenteric artery occlusion (SMAO) and then received no resuscitation or resuscitation with 4 mL/kg of HS, 4 mL/kg of lactated Ringer's (LR) solution (equal volume), or 32 mL/kg of LR solution (equal salt load). Rats were killed at 6 hours of reperfusion, and ileum was harvested for analysis. DNA fragmentation (apoptosis) was assessed by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL) and mucosal injury by histology (Chiu score 0-5). Caspase-3 (proapoptotic mediator) and Bcl-xL (antiapoptotic mediator) protein expression were analyzed by Western immunoblot.

RESULTS

SMAO with no resuscitation, SMAO with 4 mL/kg of LR, and SMAO with 32 mL/kg of LR increased apoptosis (quantitated by TUNEL) and I/R-induced mucosal injury (quantitated by Chiu score). This was associated with an increase to similar levels in both proapoptotic caspase-3 and antiapoptotic Bcl-xL protein expression. Moreover, SMAO with 4 mL/kg of HS further increased apoptosis but decreased mucosal injury. This was associated with a differential expression of proapoptotic caspase-3 over antiapoptotic Bcl-xL.

CONCLUSION

HS resuscitation after mesenteric I/R significantly increased ileal mucosal apoptosis while decreasing mucosal injury and may represent a novel mechanism by which HS resuscitation after mesenteric I/R reduces inflammation and imparts protection to the gut.