Intensive care unit management of the trauma patient

Pharmacologic Interventions to Prevent Delirium in Trauma Patients: A Systematic Review and Network Meta-Analysis of Randomized Controlled Trials

To compare the relative efficacy of pharmacologic interventions in the prevention of delirium in ICU trauma patients.

DATA SOURCES

We searched Medical Literature Analysis and Retrieval System Online, Embase, and Cochrane Registry of Clinical Trials from database inception until June 7, 2022. We included randomized controlled trials comparing pharmacologic interventions in critically ill trauma patients.

STUDY SELECTION

Two reviewers independently screened studies for eligibility, extracted data, and assessed risk of bias.

DATA EXTRACTION

Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines for network analysis were followed. Random-effects models were fit using a Bayesian approach to network meta-analysis. Between-group comparisons were estimated using hazard ratios (HRs) for dichotomous outcomes and mean differences for continuous outcomes, each with 95% credible intervals. Treatment rankings were estimated for each outcome in the form of surface under the cumulative ranking curve values.

DATA SYNTHESIS

A total 3,541 citations were screened; six randomized clinical trials (n = 382 patients) were included. Compared with combined propofol-dexmedetomidine, there may be no difference in delirium prevalence with dexmedetomidine (HR 1.44, 95% CI 0.39-6.94), propofol (HR 2.38, 95% CI 0.68-11.36), nor haloperidol (HR 3.38, 95% CI 0.65-21.79); compared with dexmedetomidine alone, there may be no effect with propofol (HR 1.66, 95% CI 0.79-3.69) nor haloperidol (HR 2.30, 95% CI 0.88-6.61).

CONCLUSIONS

The results of this network meta-analysis suggest that there is no difference found between pharmacologic interventions on delirium occurrence, length of ICU stay, length of hospital stay, or mortality, in trauma ICU patients.

Surgical Science and the Evolution of Critical Care Medicine

Surgical science has driven innovation and inquiry across adult and pediatric disciplines that provide critical care regardless of location. Surgically originated but broadly applicable knowledge has been globally shared within the pages Critical Care Medicine over the last 50 years.

Clinical efficacy and therapeutic value of delayed surgery in patients with symptomatic old thoracolumbar fractures

Background

To investigate the clinical efficacy and therapeutic value of posterior decompression reduction, bone grafting fusion, and internal fixation for treatment of symptomatic old thoracolumbar fractures.

Method

Retrospective analysis was conducted for 14 patients (9 men, 5 women; average age 40.1 years) with old thoracolumbar fractures who underwent posterior operation. American Spinal Injury Association (ASIA) scores were used to evaluate neurologic function. Vertebral body height, Cobb angle in the sagittal plane, spinal canal volume ratio (%) and bone graft fusion were analyzed by radiography and computed tomography on different follow-up times.

Results

Mean follow-up was 27.1 months (23–36 months). Of three patients with ASIA grade A, 2 had improved postoperative urination and defecation, although no classification change. Preoperative ASIA score for eight patients with incomplete injury was grade B; four patients recovered to grade C at final follow-up. Preoperative ASIA score was C in three patients, increased to D in two patients and returned to normal E in one patient. Preoperative results showed average injured vertebra height loss rate decreased from 50.4 to 8.9%; average Cobb angle on the sagittal plane recovered from 39.6 to 6.9°; and the average spinal canal volume ratio recovered from 33.8 to 5.9%. Bony fusion was achieved; local lumbago and leg pain were relieved to some extent. No patients exhibited loosening of the fracture treated by internal fixation, pseudoarthrosis, or other related serious complications.

Conclusion

Treatment of old thoracolumbar fractures by posterior decompression reduction, bone grafting fusion, and internal fixation can relieve spinal cord compression, improve neurologic function of some patients (ASIA grades B–C), effectively relieve pain, correct deformity, restore biomechanical stability, and significantly improve quality of life.

Impact of an early mobilization protocol on outcomes in trauma patients admitted to the intensive care unit: A retrospective pre-post study

BACKGROUND

Prolonged immobility has detrimental consequences for critically ill patients admitted to the intensive care unit (ICU). Previous work has shown that early mobilization of ICU patients is a safe, feasible and effective strategy to improve outcomes; however, few of these studies focused on trauma ICU patients. Our objective was to assess the impact of implementing an ICU early mobilization protocol (EMP) on trauma outcomes.

METHODS

We conducted a retrospective pre-post study of adult trauma patients (>18 years old) admitted to ICU at a Level I trauma center over a 2-year period prior to and following EMP implementation, allowing for a 1-year transition period. Data were collected from the Nova Scotia Trauma Registry. We compared outcomes (mortality, length of stay [LOS], ventilator-free days) between patients admitted during pre-EMP and post-EMP periods, and assessed for factors associated with outcomes using binary logistic regression and generalized linear models.

RESULTS

Overall, 526 patients were included in the analysis (292 pre-EMP, 234 post-EMP). Ages ranged from 18 years to 92 years (mean, 49.0 ± 20.4 years) and 74.3% were men. The post-EMP group had lower ICU mortality (21.6% vs. 12.8%; p = 0.009) and in-hospital mortality (25.3% vs. 17.5%; p = 0.031). After controlling for confounders, patients in the post-EMP group were less likely to die in the ICU (odds ratio, 0.43; 95% confidence interval, 0.24-0.79; p = 0.006) or in-hospital (odds ratio, 0.55; 95% confidence interval; 0.32-0.94; p = 0.03). In-hospital LOS, ICU LOS, ICU-free days, and number of ventilator-free days were similar between the two groups.

CONCLUSION

Trauma patients admitted to ICU during the post-EMP period had decreased odds of ICU mortality and in-hospital mortality. This is the first study to demonstrate a significant reduction in trauma mortality following implementation of an ICU mobility protocol.

LEVEL OF EVIDENCE

Therapeutic, level III.

Early mobilization of trauma patients admitted to intensive care units: A systematic review and meta-analyses

OBJECTIVE

To determine the effect of early mobilization (EM) in trauma patients admitted to the ICU. Outcomes of interest included mortality, hospital and ICU length of stay (LOS), and duration of mechanical ventilation.

METHODS

We performed a systematic review of 4 electronic databases (Ovid MEDLINE, Embase, CINAHL, Cochrane Library) and the grey literature. Eligible study designs included randomized control trials, prospective cohorts, or retrospective cohorts. Studies must have compared EM to usual care (i.e., delayed or no mobilization) in trauma patients admitted to ICU. Overall, there were 2982 articles screened and 9 were included in the analysis. Two authors independently performed data extraction using a standardized form. Pertinent study design and population characteristics were recorded, as were prespecified outcome measures. Meta-analyses were performed using random effects models. Study quality was assessed using the Newcastle-Ottawa Scale.

RESULTS

Study cohorts ranged from 15 to 1132 patients (median 63) and varied in their inclusion criteria. Most studies utilized a progressive mobility protocol as their intervention. Mortality was reported in 5 studies, of which 3 observed a lower rate with EM; however, meta-analysis showed no difference in mortality between patients mobilized early and those receiving usual care. Eight studies reported on LOS (in-hospital and ICU); although all 8 studies found EM reduced LOS, the difference in LOS was not significant on meta-analysis. Finally, 3 studies reported on ventilator days, all of which observed a reduction in the EM group. On meta-analysis, duration of mechanical ventilation was significantly lower with EM (mean difference -1.18 days, 95% CI, -2.17 - -0.19).

CONCLUSIONS

Few studies have investigated the effects of EM in trauma ICU patients. The available evidence suggests that patients who receive EM require fewer days of mechanical ventilation, but have similar mortality and LOS compared to those receiving usual care.

Is Emergency Transcatheter Hepatic Arterial Embolization Suitable for Spontaneously Ruptured Hepatocellular Carcinoma in Child-Pugh C Cirrhosis?

PURPOSE

To evaluate the utility of emergent transcatheter arterial embolization for spontaneously ruptured hepatocellular carcinoma (HCC) in patients with Child-Pugh class C (CPC) liver cirrhosis presenting hemorrhagic shock.

MATERIALS AND METHODS

A study of all 94 patients was retrospectively conducted from January 2006 to January 2016. Sixty patients underwent conservative treatment (control group) and 34 underwent embolization.

RESULTS

Embolization provided better stabilization of hemodynamic status than conservative treatment (91.2% vs 61.7%), with greater overall survival (OS) rates at 30, 60, and 120 days (73.5%, 52.9%, and 29.4% vs 33.3%, 13.3%, and 0%, respectively). Mean follow-up duration was 51.07 days (range, 3-237 d). Median survival time was longer for the embolization group than the control group, specifically for patients with a shock index (SI) of ≥ 0.6 to < 1 (106.0 d ± 39.4 vs 34.0 d ± 4.7) or ≥ 1 (18.0 d ± 7.5 vs 11.0 d ± 3.2), those with CPC scores 10 or 11 (88.0 d ± 29.4 vs 28.0 d ± 4.5), and those with segmental (165.0 d ± 20.6 vs 34.0 d ± 9.7) or lobar (54.0 d ± 7.9 vs 26.0 d ± 3.4) portal vein tumor thrombus (PVTT). SI ≥ 1, Child-Pugh score of 12/13, tumor size ≥ 10 cm, and PVTT were independent factors in poor prognosis for OS.

CONCLUSIONS

Emergent transcatheter arterial embolization is an effective intervention for ruptured HCC in patients with CPC liver function in hemorrhagic shock, particularly those with a SI ≥ 1, Child-Pugh scores of 10/11, and first- or lower-order PVTT.

Intensive care organisation: Should there be a separate intensive care unit for critically injured patients?

In the last two decennia, the mixed population general intensive care unit (ICU) with a “closed format” setting has gained in favour compared to the specialized critical care units with an “open format” setting. However, there are still questions whether surgical patients benefit from a general mixed ICU. Trauma is a significant cause of morbidity and mortality throughout the world. Major or severe trauma requiring immediate surgical intervention and/or intensive care treatment. The role and type of the ICU has received very little attention in the literature when analyzing outcomes from critical injuries. Severely injured patients require the years of experience in complex trauma care that only a surgery/trauma ICU can provide. Should a trauma center have the capability of a separate specialized ICU for trauma patients (“closed format”) next to its standard general mixed ICU

Shock index and prediction of traumatic hemorrhagic shock 28-day mortality: data from the DCLHb resuscitation clinical trials

INTRODUCTION

To assess the ability of the shock index (SI) to predict 28-day mortality in traumatic hemorrhagic shock patients treated in the diaspirin cross-linked hemoglobin (DCLHb) resuscitation clinical trials.

METHODS

We used data from two parallel DCLHb traumatic hemorrhagic shock efficacy trials, one in U.S. emergency departments, and one in the European Union prehospital setting to assess the relationship between SI values and 28-day mortality.

RESULTS

In the 219 patients, the mean age was 37 years, 64% sustained a blunt injury, 48% received DCLHb, 36% died, and 88% had an SI≥1.0 at study entry. The percentage of patients with an SI≥1.0 dropped by 57% (88 to 38%) from the time of study entry to 120 minutes after study resuscitation (p<0.001). Patients with a SI≥1.0, 1.4, and 1.8 at any time point were 2.3, 2.7, and 3.1 times, respectively, more likely to die by 28 days than were patients with SI values below these cutoffs (p<0.001). Similarly, after 120 minutes of resuscitation, patients with a SI≥1.0 were 3.9× times more likely to die by 28 days (40 vs. 15%, p<0.001). Although the distribution of SI values differed based on treatment group, the receiver operator characeristics data showed no difference in SI predictive ability for 28-day mortality in patients treated with DCLHb.

CONCLUSION

In these traumatic hemorrhagic shock patients, the shock index correlates with 28-day mortality, with higher SI values indicating greater mortality risk. Although DCLHb treatment did alter the distribution of SI values, it did not influence the ability of the SI to predict 28-day mortality.

A trauma quality improvement programme associated with improved patient outcomes: 21 years of experience at an Australian Major Trauma Centre

INTRODUCTION

Quality improvement programmes are an important part of care delivery in trauma centres. The objective was to describe the effect of a comprehensive quality improvement programme on long term patient outcome trends at a low volume major trauma centre in Australia.

METHODS

All patients aged 15 years and over with major trauma (Injury Severity Score>15) admitted to a single inner city major trauma centre between 1992 and 2012 were studied. The outcomes of interest were in-hospital mortality and transfer to rehabilitation. Time series analysis using integer valued autoregressive Poisson models was used to determine the reduction in adjusted monthly count data associated with the intervention period (2007-2012). Risk adjusted odds ratios for mortality over three yearly intervals was also obtained using multivariable logistic regression. Crude and risk adjusted mortality was compared before and after the implementation period.

RESULTS

3856 patients were analysed. Crude in-hospital mortality fell from 16% to 10% after implementation (p<0.001). The intervention period was associated with a 25% decrease in monthly mortality counts. Risk adjusted mortality remained stable from 1992 to 2006 and did not fall until the intervention period. Crude and risk adjusted transfer to in-patient rehabilitation after major trauma also declined during the intervention period.

CONCLUSION

In this low volume major trauma centre, the implementation of a comprehensive quality improvement programme was associated with a reduction in crude and risk adjusted mortality and risk adjusted discharge to rehabilitation in severely injured patients.

A comparison of the treatment of severe injuries between the former East and West German States

BACKGROUND

The annual number of persons killed in road-traffic accidents in Germany declined by 36% from 2001 to 2008, yet official traffic statistics still reveal a marked difference in fatalities between the federal states of the former East and West Germany twenty years after German reunification.

METHODS

We retrospectively analyzed data from the Trauma Registry of the German Trauma Society (Deutsche Gesellschaft für Unfallchirurgie; TR-DGU). Patients receiving primary treatment that had an Injury Severity Score (ISS) of 9 or above were analyzed separately depending on whether they were treated in the former East Germany or the former West Germany.

RESULTS

Data were obtained from a total of 26 866 road-accident trauma cases. With Berlin excluded, 2597 cases (10.2%) were from the former East Germany (EG), and 22 966 (89.9%) were from the former West Germany (WG). The percentage of the population living in these two parts of the country is 16.7% and 83.3%, respectively. The two groups did not differ significantly in either the mortality of injuries (EG 15.8%, WG 15.7%) or in the standardized mortality rate (0.89 [EG] vs. 0.88 [WG]). Over the years 2002-2008, the mean time to arrival of the emergency medical services on the scene was 19 minutes (EG) vs. 17 minutes (WG), and the mean time to arrival in hospital was 76 minutes (EG) vs. 69 minutes (WG).

CONCLUSION

Among the hospitals whose cases are included in the TR-DGU, there is no significant difference between the former East and West Germany with respect to mortality or any other clinically relevant variable. Hypothetically, the higher rate of death from road-traffic accidents in the former East Germany, as revealed by national traffic statistics, might be attributable to a difference in the quality of care received by trauma patients, but no such difference was found. Other potential reasons for it might be poorer road conditions, more initially fatal accidents, and lower accessibility of medical care in less densely populated areas.

The timing of definitive fixation for major fractures in polytrauma--a matched-pair comparison between a US and European level I centres: analysis of current fracture management practice in polytrauma

PURPOSE

Early definitive stabilisation is usually the treatment of choice for major fractures in polytrauma patients. Modifications may be made when patients are in critical condition, or when associated injuries dictate the timing of surgery. The current study investigates whether the timing of fracture treatment is different in different trauma systems.

MATERIALS AND METHODS

Consecutive patients treated a Level I trauma centre were documented (Group US) and a matched-pair group was gathered from the German Trauma Registry (Group GTR).

INCLUSION CRITERIA

New Injury Severity Score (NISS)>16, >2 major fractures and >1 organ/soft tissue injury. The timing and type of surgery for major fractures was recorded, as were major complications.

RESULTS

114 patients were included, n=57 Group US (35.1% F, 64.9% M, mean age: 44.1 yrs±16.49, mean NISS: 27.4±8.65, mean ICU stay: 10±7.49) and n=57 Group GTR (36.8% F, 63.1% M, mean age: 41.2 yrs±15.35, mean NISS: 29.4±6.88, mean ICU stay: 15.6±18.25). 44 (57.1%) out of 77 fractures in Group US received primary definitive fracture fixation compared to 61 (65.5%) out of 93 fractures in Group GTR (n.s.). The average duration until definitive treatment was comparable in all major extremity fractures (pelvis: 5 days±2.8 Group US, 7.1 days±9.6 Group GTR (n.s.), femur: 7.9 days±8.3 Group US, 5.5 days±7.9 (n.s.), tibia: 6.2 days±5.6 Group US, 6.2 days±9.1 Group GTR (n.s.), humerus: 5 days±3.7 Group US, 6.6 days±6.1 Group GTR (n.s.), radius: 6 days±4.7 Group US, 6.1 days±8.7 Group GTR (n.s.).

CONCLUSION

The current matched-pair analysis demonstrates that the timing of initial definitive fixation of major fractures is comparable between the US and Europe. Certain fractures are stabilised internally in a staged fashion regardless the trauma system, thus discounting previous apparent contradictions.

Surgical intensive care unit--the trauma surgery perspective

PURPOSE

This review addresses and summarizes the key issues and unique specific intensive care treatment of adult patients from the trauma surgery perspective.

MATERIALS AND METHODS

The cornerstones of successful surgical intensive care management are fluid resuscitation, transfusion protocol and extracorporeal organ replacement therapies. The injury-type specific complications and unique pathophysiologic regulatory mechanisms of the traumatized patients influencing the critical care treatment are discussed.

CONCLUSIONS

Furthermore, the fundamental knowledge of the injury severity, understanding of the trauma mechanism, surgical treatment strategies and specific techniques of surgical intensive care are pointed out as essentials for a successful intensive care therapy.

The redox status of experimental hemorrhagic shock as measured by cyclic voltammetry

Hemorrhagic shock (HS) leads to reactive oxygen species production. However, clinicians do not have access to bedside measurements of the redox status during HS. Cyclic voltammetry (CyV) is a simple electrochemical method of measuring redox status. The aims of this study were to 1) report the first application of cyclic voltammetry to measure the acute changes in serum redox status after HS, 2) to contrast it with another severe systemic disease with a different redox pathology (acute pancreatitis [AP]), and 3) to describe the response of CyV over time in a resolving model of AP. In the acute study, 24 male Wistar rats were randomized into three groups: groups 1 (control), 2 (AP), and 3 (HS). In the time-course study, 28 rats were randomized to a sham-control as well as 6 and 24 h post-AP cohorts, respectively.Cyclic voltammetry was performed using a three-electrode system. In the acute study, the first and second voltammetric peaks increased significantly in HS. In contrast, within the AP group, only the first voltammetric peak showed a significant increase. The first voltammetric peak correlated with plasma protein carbonyls (PCs) and with thiobarbituric acid-reactive substances, whereas the second voltammetric peak correlated positively with plasma protein carbonyls. In the second study, the first voltammetric peak correlated with physiological improvements. Here, we showed that serum CyV could respond to the serum redox change in HS and AP. Cyclic voltammetry warrants evaluation as a potential real-time beside measure of a patient's redox status during shock.

Common drug interactions leading to adverse drug events in the intensive care unit: management and pharmacokinetic considerations

Critically ill patients are predisposed to drug interactions because of the complexity of the drug regimens they receive in the intensive care setting. Drugs may affect the absorption, distribution, metabolism, and/or elimination of an object drug and consequently alter the intended pharmacologic response and potentially lead to an adverse event. Certain disease states that afflict critically ill patients may also amplify an intended pharmacologic response and potentially result in an unintended effect. A team approach is important to identify, prevent, and address drug interactions in the intensive care setting and optimize patient outcomes.

Trauma in pregnancy

In the United States, trauma is the leading nonobstetric cause of maternal death. The principal causes of trauma in pregnancy include motor vehicle accidents, falls, assaults, homicides, domestic violence, and penetrating wounds. The managing team evaluating and coordinating the care of the pregnant trauma patient should be multidisciplinary so that it is able to understand the physiologic changes in pregnancy. Blunt trauma to the abdomen increases the risk of placental abruption. Evaluation of the pregnant trauma patient requires a primary and secondary survey with emphasis on airway, breathing, circulation, and disability. The use of imaging studies, invasive hemodynamics, critical care medications, and surgery, if necessary, should be individualized and guided by a coordinating team effort to improve maternal and fetal conditions. A clear understanding of gestational age and fetal viability should be documented in the record.

The lack of consistent diaspirin cross-linked hemoglobin infusion blood pressure effects in the US and EU traumatic hemorrhagic shock clinical trials

Hemoglobin solutions have demonstrated a pressor effect that could adversely affect hemorrhagic shock patient resuscitation through accelerated hemorrhage, diminished perfusion, or inadequate resuscitation. Data from two parallel, multicenter traumatic hemorrhagic shock clinical trials in 17 US emergency departments and in 27 EU prehospital systems using diaspirin cross-linked hemoglobin (DCLHb), a hemoglobin-based resuscitation fluid. In the 219 patients, patients were 37 years old, 64% sustained blunt injury, 48% received DCLHb, and 36% expired. Although mean systolic blood pressure (SBP) and diastolic blood pressure values differed at 2 of the 10 measured time points, blood pressure (BP) curve analysis showed no SBP, diastolic blood pressure, or MAP differences based on treatment. Although SBP values 160 and 120 mmHg or greater were 2.2x and 2.6x more frequently noted in survivors, they were not more common with DCLHb use or in DCLHb patients who expired in US study nonsurvivors or in any EU study patients. Systolic blood pressure values 160 and 120 mmHg or greater were 2.8x and 1.3x more frequently noted in DCLHb survivors as compared with normal saline survivors. Only 3% of the BP variation noted could be attributed to DCLHb use, and as expected, injury severity and baseline physiologic status were stronger predictors. In the United States alone, treatment group was not correlated by regression with BP at any time point. Neither mean BP readings nor elevated BP readings were correlated with DCLHb treatment of traumatic hemorrhagic shock patients. As such, no clinically demonstrable DCLHb pressor effect could be directly related to the adverse mortality outcome observed in the US study.

Is dopexamine superior to dopamine in the treatment of multiple trauma patients--a prospective, double-blind, randomised study

BACKGROUND

The goal of this prospective, randomised, double-blind clinical trial study was to assess the effects of dopexamine hydrochloride on organ failure, inflammatory mediators and splanchnic oxygenation in blunt multiple trauma patients at high risk of multiple organ dysfunction syndrome (MODS).

METHODS

We performed a prospective randomised controlled trial on 30 consecutive blunt multiple trauma patients with ISS>or=16, age 18-60 years and initial blood pressure >or=120 mmHg initially admitted to our level I trauma centre. Patients were randomised to treatment with dopamine (n=15) or dopexamine (n=15) for 48 h after admission. Outcome in terms of mortality, MODS, splanchnic perfusion, complications, duration of stay was statistically analysed.

RESULTS

Dopexamine treatment was associated with impaired organ function and an increased duration of ventilation and ICU stay compared with patients who received dopamine treatment. The acute inflammatory response was increased in the Dopexamine group while a decreased pHi and MEGX formation and increased serum lactate levels were measured.

CONCLUSIONS

The indication to use dopexamine hydrochloride appears questionable. In the absence of an antiinflammatory effect, dopexamine demonstrated a disadvantageous ICU course in regards to the organ function and the duration of treatment. In addition, a decreased pHi and MEGX formation suggested a deterioration of splanchnic oxygenation.

Pharmacological optimization of tissue perfusion

After fluid resuscitation, vasoactive drug treatment represents the major cornerstone for correcting any major impairment of the circulation. However, debate still rages as to the choice of agent, dose, timing, targets, and monitoring modalities that should optimally be used to benefit the patient yet, at the same time, minimize harm. This review highlights these areas and some new pharmacological agents that broaden our therapeutic options.

Microcirculatory parameters after isotonic and hypertonic colloidal fluid resuscitation in acute hemorrhagic shock

BACKGROUND

Volume resuscitation is one of the primary therapeutic goals in hemorrhagic shock, but data on microcirculatory effects of different colloidal fluid resuscitation regimen are sparse. We investigated sublingual mucosal microcirculatory parameters during hemorrhage and after fluid resuscitation with gelatin, hydroxyethyl starch, or hypertonic saline and hydroxyethyl starch in pigs.

METHODS

To induce hemorrhagic shock, 60% of calculated blood volume was withdrawn. Microvascular blood flow was assessed by laser Doppler velocimetry. Microcirculatory hemoglobin oxygen saturation was measured with a tissue reflectance spectrophotometry, and side darkfield imaging was used to visualize the microcirculation and to quantify the flow quality. Systemic hemodynamic variables, systemic acid base and blood gas variables, and lactate measurements were recorded. Measurements were performed at baseline, after hemorrhage, and after fluid resuscitation with a fixed volume regimen.

RESULTS

Systemic hemodynamic parameters returned or even exceeded to baseline values in all three groups after fluid resuscitation, but showed significantly higher filling pressures and cardiac output values in animals treated with isotonic colloids. Microcirculatory parameters determined in gelatin and hydroxyethyl starch resuscitated animals, and almost all parameters except microvascular hemoglobin oxygen saturation in animals treated with hypertonic saline and hydroxyethyl starch, were restored after treatment.

DISCUSSION

Hemorrhaged pigs can be hemodynamically stabilized with either isotonic or hypertonic colloidal fluids. The main finding is an adequate restoration of sublingual microcirculatory blood flow and flow quality in all three study groups, but only gelatin and hydroxyethyl starch improved microvascular hemoglobin oxygen saturation, indicating some inadequate oxygen supply/demand ratio maybe due to a better restoration of systemic hemodynamics in isotonic colloidal resuscitated animals.

Aging and animal models of systemic insult: trauma, burn, and sepsis

In the acute-care setting, it is widely accepted that elderly patients have increased morbidity and mortality compared with young healthy patients. The reasons for this, however, are largely unknown. Although animal modeling has helped improve treatment strategies for young patients, there are a scarce number of studies attempting to understand the mechanisms of systemic insults such as trauma, burn, and sepsis in aged individuals. This review aims to highlight the relevance of using animals to study the pathogenesis of these insults in the aged and, despite the deficiency of information, to summarize what is currently known in this field.

Probiotics prevent intestinal barrier dysfunction in acute pancreatitis in rats via induction of ileal mucosal glutathione biosynthesis

Background

During acute pancreatitis (AP), oxidative stress contributes to intestinal barrier failure. We studied actions of multispecies probiotics on barrier dysfunction and oxidative stress in experimental AP.

Methodology/Principal Findings

Fifty-three male Spraque-Dawley rats were randomly allocated into five groups: 1) controls, non-operated, 2) sham-operated, 3) AP, 4) AP and probiotics and 5) AP and placebo. AP was induced by intraductal glycodeoxycholate infusion and intravenous cerulein (6 h). Daily probiotics or placebo were administered intragastrically, starting five days prior to AP. After cerulein infusion, ileal mucosa was collected for measurements of E. coli K12 and ⁵¹Cr-EDTA passage in Ussing chambers. Tight junction proteins were investigated by confocal immunofluorescence imaging. Ileal mucosal apoptosis, lipid peroxidation, and glutathione levels were determined and glutamate-cysteine-ligase activity and expression were quantified. AP-induced barrier dysfunction was characterized by epithelial cell apoptosis and alterations of tight junction proteins (i.e. disruption of occludin and claudin-1 and up-regulation of claudin-2) and correlated with lipid peroxidation (r>0.8). Probiotic pre-treatment diminished the AP-induced increase in E. coli passage (probiotics 57.4±33.5 vs. placebo 223.7±93.7 a.u.; P<0.001), ⁵¹Cr-EDTA flux (16.7±10.1 vs. 32.1±10.0 cm/s10⁻⁶; P<0.005), apoptosis, lipid peroxidation (0.42±0.13 vs. 1.62±0.53 pmol MDA/mg protein; P<0.001), and prevented tight junction protein disruption. AP-induced decline in glutathione was not only prevented (14.33±1.47 vs. 8.82±1.30 nmol/mg protein, P<0.001), but probiotics even increased mucosal glutathione compared with sham rats (14.33±1.47 vs. 10.70±1.74 nmol/mg protein, P<0.001). Glutamate-cysteine-ligase activity, which is rate-limiting in glutathione biosynthesis, was enhanced in probiotic pre-treated animals (probiotics 2.88±1.21 vs. placebo 1.94±0.55 nmol/min/mg protein; P<0.05) coinciding with an increase in mRNA expression of glutamate-cysteine-ligase catalytic (GCLc) and modifier (GCLm) subunits.

Conclusions

Probiotic pre-treatment diminished AP-induced intestinal barrier dysfunction and prevented oxidative stress via mechanisms mainly involving mucosal glutathione biosynthesis.

Arginine vasopressin: a promising rescue drug in the treatment of uncontrolled haemorrhagic shock

Haemorrhagic shock is one of the most frequent types of shock. If haemorrhage cannot be controlled and fluid resuscitation as well as catecholamines are insufficient to stabilize cardiovascular function, uncontrolled haemorrhagic shock occurs. Several approaches have been suggested as promising alternatives to volume resuscitation. The rationale for the use of arginine vasopressin (AVP) is the pharmacologic amplification of the neuroendocrine stress response. AVP-mediated vasoconstriction is the first physiologic step to haemostasis and shifts blood away from the bleeding site towards the heart, lungs and brain. Particularly, when uncontrolled haemorrhage is accompanied by traumatic brain injury this may help to reduce secondary neurological damage. Since AVP can prevent acute death only transiently, it must comprehensively be combined with rapid hospital admission, immediate control of haemorrhage followed by aggressive fluid resuscitation and blood transfusion. This review article summarizes current experimental and clinical evidence on the use of AVP in uncontrolled haemorrhagic shock.

Purification and characterization of human adrenomedullin binding protein-1

We recently discovered that the vascular responsiveness to adrenomedullin (AM), a potent vasoactive peptide, decreased during sepsis and hemorrhage in the rat and was markedly improved by its novel binding protein (AMBP-1). Moreover, AM/AMBP-1 appears to be one of the leading candidates for further development to treat sepsis and hemorrhage. However, the extremely high cost of commercial AMBP-1 limits the development of human AM and AMBP-1 as therapeutic agents. The purpose of this study was to isolate and purify AMBP-1 from normal human serum and test its stability and biological activity under in vitro and in vivo conditions. AMBP-1 was isolated and purified from normal human serum with a yield of about 3.0 mg per 100 mL and purity of >99%. The purified AMBP-1 has a AM-binding capacity similar to that of the commercial AMBP-1. Human AM and human AMBP-1 in combination significantly inhibited lipopolysaccharide-induced tumor necrosis factor (TNF)-alpha and interleukin (IL)-6 production from macrophages. The biological activity of the purified human AMBP-1 was well preserved when stored at 45 degrees C for 5 d in solution or at 100 degrees C for 1 h in powder. Moreover, administration of AM and purified AMBP-1 to hemorrhaged rats attenuated tissue injury and neutrophil accumulation. Purified AMBP-1 in combination with AM also suppressed the hemorrhage-induced rise in serum cytokines TNF-alpha and IL-6. Thus, we have successfully purified biologically active AMBP-1 from human normal serum and demonstrated the stability of purified human AMBP-1. This technique will enable us to further develop human AM/AMBP-1 as a novel treatment for safe and effective therapy of patients with hemorrhagic shock, sepsis, and ischemic injury.

Human vasoactive hormone adrenomedullin and its binding protein rescue experimental animals from shock

We recently discovered that vascular responsiveness to adrenomedullin (AM), a vasoactive hormone, decreases after hemorrhage, which is markedly improved by the addition of its binding protein AMBP-1. One obstacle hampering the development of AM/AMBP-1 as resuscitation agents in trauma victims is the potential immunogenicity of rat proteins in humans. Although less potent than rat AM, human AM has been shown to increase organ perfusion in rats. We therefore hypothesized that administration of human AM/AMBP-1 improves organ function and survival after severe blood loss in rats. To test this, male Sprague-Dawley rats were bled to and maintained at an MAP of 40 mmHg for 90 min. They were then resuscitated with an equal volume of shed blood in the form of Ringer's lactate (i.e., low-volume resuscitation) over 60 min. At 15 min after the beginning of resuscitation, human AM/AMBP-1 (12/40 or 48/160 microg/kg BW) were administered intravenously over 45 min. Various pathophysiological parameters were measured 4h after resuscitation. In additional groups of animals, a 12-day survival study was conducted. Our result showed that tissue injury as evidenced by increased levels of transaminases, lactate, and creatinine, was present at 4h after hemorrhage and resuscitation. Moreover, pro-inflammatory cytokines TNF-alpha and IL-6 were also significantly elevated. Administration of AM/AMBP-1 markedly attenuated tissue injury, reduced cytokine levels, and improved the survival rate from 29% (vehicle) to 62% (low-dose) or 70% (high-dose). However, neither human AM alone nor human AMBP-1 alone prevented the significant increase in ALT, AST, lactate and creatinine at 4h after the completion of hemorrhage and resuscitation. Moreover, the half-life of human AM and human AMBP-1 in rats was 35.8 min and 1.68 h, respectively. Thus, administration of human AM/AMBP-1 may be a useful approach for attenuating organ injury, and reducing mortality after hemorrhagic shock.

Haemorrhagic shock therapy

BACKGROUND

Severe injury is often associated with haemorrhagic shock and this is the most common cause of preventable mortality after injury. Care of the injured patient in shock involves an overlapping continuum of care beginning during the prehospital phase of care and extending through the interventional and critical care phases.

OBJECTIVE

This study aimed to review emerging therapies in the treatment of haemorrhagic shock.

METHODS

A review of recent clinical articles (1996 - 2007) examining therapeutic measures for haemorrhagic shock treatment was undertaken.

CONCLUSIONS

Although the mainstay of therapy continues to be obtaining haemostasis and restoring tissue perfusion, a multitude of novel strategies are emerging, including advanced haemostatic agents, hypertonic resuscitation and massive transfusion protocols, as well as blood substitutes and an improved understanding of damage control principles, thereby allowing increased survival and improved outcomes in the severely injured patient with major haemorrhage.

Functional significance of gene polymorphisms in the promoter of myeloid differentiation-2

OBJECTIVE

To investigate the functional significance of the reported single nucleotide polymorphisms (SNPs) in the promoter of the myeloid differentiation-2 (MD-2) gene.

SUMMARY BACKGROUND DATA

Functional gene polymorphisms of innate immune receptors have been shown to be critical determinants of the immune inflammatory response. MD-2 is an important signaling enhancer protein in the endotoxin (LPS) receptor complex. Although a total of 156 SNPs have been identified within the whole MD-2 gene, little is known about the functional significance of these SNPs.

METHODS

: The possible biosignificance of 8 reported SNPs was analyzed using on-line software tools. The selected SNPs were then genotyped using a restriction fragment length polymorphism method applied to 711 healthy Chinese volunteers. Their functional effects were assessed by the observation of transcription activity, MD-2 mRNA expression, and leukocyte response to ex vitro LPS stimulation. Moreover, the clinical relevance of these SNPs was investigated in 105 patients with major trauma.

RESULTS

Three SNPs (C-1625G, A-1064G, and A-475T) in the MD-2 promoter were selected based on bio-informatic analysis. Both -1625 and -1064 SNPs, rather than -475, were seen in the Chinese population, with frequencies of 19.8% (-1625G) and 34.7% (-1064G). But only the -1625 polymorphism was found to affect MD-2 promoter activity. Moreover, the expression of MD-2 mRNA and the production of TNF-alpha in whole blood leukocytes, in response to LPS stimulation, were significantly increased in subjects with the -1625 G allele. Patients who possessed the -1625 G allele were more likely to experience complications with organ dysfunction and sepsis after major trauma. All these associations were in allele-dose dependent effect.

CONCLUSIONS

The MD-2/-1625 polymorphism is an important functional variant.