The Role and Use of Estrogens Following Trauma

Multicompartmental Trauma Induces Persistent Inflammation and Organ Injury

INTRODUCTION

Previous preclinical models of multicompartmental injury have investigated its effects for durations of less than 72 h and the long-term effects have not been defined. We hypothesized that a model of multicompartmental injury would result in systemic inflammation and multiorgan dysfunction that persists at 1 wk.

METHODS

Male and proestrus female Sprague-Dawley rats (n = 16/group) underwent polytrauma (PT) (unilateral right lung contusion, hemorrhagic shock, cecectomy, bifemoral pseudofractures) and were compared to naive controls. Weight, hemoglobin, plasma neutrophil gelatinase-associated lipocalin, and plasma toll-like receptor 4 were evaluated on days two and seven. Bilateral lungs were sectioned, stained and assessed for injury at day seven. Comparisons were performed in Graphpad with significance defined as ∗P <0.05.

RESULTS

Rats who underwent PT had significant weight loss and anemia at day 2 (P = 0.001) compared to naïve rats which persisted at day 7 (P = 0.001). PT rats had elevated plasma neutrophil gelatinase-associated lipocalin at day 2 compared to naïve (P <0.0001) which remained elevated at day 7 (P <0.0001). Plasma toll-like receptor 4 was elevated in PT compared to naïve at day 2 (P = 0.03) and day 7 (P = 0.01). Bilateral lungs showed significant injury in PT cohorts at day 7 compared to naïve (P <0.0004). PT males had worse renal function at day seven compared to females (P = 0.02).

CONCLUSIONS

Multicompartmental trauma induces systemic inflammation and multiorgan dysfunction without recovery by day seven. However, females demonstrate improved renal recovery compared to males. Long-term assessment of preclinical PT models are crucial to better understand and evaluate future therapeutic immunomodulatory and anti-inflammatory treatments.

ESTROGEN ALLEVIATES POSTHEMORRHAGIC SHOCK MESENTERIC LYMPH-MEDIATED LUNG INJURY THROUGH AUTOPHAGY INHIBITION

ABSTRACT

Background: Hemorrhagic shock-induced acute lung injury (ALI) is commonly associated with the posthemorrhagic shock mesenteric lymph (PHSML) return. Whether excessive autophagy is involved in PHSML-mediated ALI remains unclear. The relationship between estrogen treatment and PHSML or autophagy needs to verify. The current study will clarify the role of estrogen in reducing PHSML-mediated ALI through inhibition of autophagy. Methods: First, a hemorrhagic shock model in conscious rats was used to observe the effects of 17β-estradiol (E2) on intestinal blood flow, pulmonary function, intestinal and pulmonary morphology, and expression of autophagy marker proteins. Meanwhile, the effect of PHSML and autophagy agonist during E2 treatment was also investigated. Secondly, rat primary pulmonary microvascular endothelial cells were used to observe the effect of PHSML, PHSML plus E2, and E2-PHSML (PHSML obtained from rats treated by E2) on the cell viability. Results: Hemorrhagic shock induced intestinal and pulmonary tissue damage and increased wet/dry ratio, reduced intestinal blood flow, along with pulmonary dysfunction characterized by increased functional residual capacity and lung resistance and decreased inspiratory capacity and peak expiratory flow. Hemorrhagic shock also enhanced the autophagy levels in intestinal and pulmonary tissue, which was characterized by increased expressions of LC3 II/I and Beclin-1 and decreased expression of p62. E2 treatment significantly attenuated these adverse changes after hemorrhagic shock, which was reversed by PHSML or rapamycin administration. Importantly, PHSML incubation decreased the viability of pulmonary microvascular endothelial cells, while E2 coincubation or E2-treated lymph counteracted the adverse roles of PHSML. Conclusions: The role of estrogen reducing PHSML-mediated ALI is associated with the inhibition of autophagy.

The outcome of severely injured patients following traumatic brain injury is affected by gender-A retrospective, multicenter, matched-pair analysis utilizing data of the TraumaRegister DGU®

INTRODUCTION

Traumatic brain injury (TBI) causes a major health-concern globally. Gender-dependent differences in mortality outcome after TBI have been controversially discussed.

MATERIALS AND METHODS

We conducted a retrospective, multicenter, matched-pair analysis using data collected by the TraumaRegister DGU® of the German Trauma Society between 2009 and 2020. All patients after severe trauma with the leading injury of TBI (AIS ≥ 3), above 18 years of age were included. Thereby, 42,034 cases were identified. We used 12 different matching criteria to ensure highly accurate matching and were able to match 11,738 pairs of one female and one male patient.

RESULTS

Average age at injury was 67.5 ± 19.6 years in women and 66.7 ± 19.1 years in men. Mean Injury Severity Score (ISS) was 21.3 ± 8.1 in women and 21.6 ± 8.2 in men. While women were more likely to die within the first week after trauma, the mortality was significantly higher in men overall (30.8 vs. 29.2%, p < 0.002). Women were less likely to suffer from multi organ failure (MOF) (27.5 vs. 33.0%) or sepsis (4.5 vs. 7.1%). When comparing younger (≤ 45-years) and older (> 45 years) patients, overall mortality was lower in men (13.1% men vs. 13.4% women) in the younger age group, but in the older group mortality was lower in women (33.8% men vs. 31.8% women).

DISCUSSION

Gender-specific differences in the clinical outcome of severely injured patients with leading TBI could be detected. While women are overall characterized by an advantage in survival, this feature is not equally reproducible in premenopausal women. Therefore, the exact pathophysiological reasons for the described survival advantages of women will have to be explored in further prospective clinical studies.

Patient age affects sex-based differences in post-traumatic mortality: a national trauma registry study in Japan

PURPOSE

Sex-based differences in post-traumatic mortality have been widely discussed for quite some time. We hypothesized that age-related pathophysiologic changes would affect sex-based differences in post-traumatic mortality and aimed to verify the hypothesis using a nationwide trauma registry in Japan.

METHODS

This was a retrospective analysis of trauma patients registered in The Japanese Trauma Data Bank. We stratified the study population into the following three subsets based on age: (1) pediatric subset (age ≤ 14), (2) adult subset (age 15-50) and (3) senior adult subset (age ≥ 51). We evaluated both sex-based differences in mortality in each subset separately using multivariate logistic regression analysis and the two-way interaction effect for predicted survival between the continuous increase of age and the sexes using a nonlinear multivariate regression model.

RESULTS

We included 122,819 trauma patients who fulfilled the inclusion criteria and classified them into the 3 subsets according to age. Male patients were more likely to die compared to female patients only in the senior adult subset (adjusted odds ratio: 1.26; 95% confidence interval: 1.18-1.36), whereas there were no statistically significant differences in the other two subsets. Furthermore, non-linear logistic regression analysis revealed that predicted survival probability in male patients decreased more sharply in accordance with the increase of age compared to that in female patients (p for interaction: 0.051).

CONCLUSION

Age-related change in post-traumatic mortality was significantly different between males and females, and male patients had a relatively higher risk of death in the older population.

Mesenteric Lymph Drainage Improves Cardiac Papillary Contractility and Calcium Sensitivity in Rats with Hemorrhagic Shock

BACKGROUND

Myocardial dysfunction is an important adverse factor of hemorrhagic shock that induces refractory hypotension, and post-hemorrhagic shock mesenteric lymph (PHSML) return is involved in this adverse effect. This study investigated whether mesenteric lymph drainage (MLD) improves PHSML return-induced cardiac contractile dysfunction via the restoration of cardiomyocyte calcium sensitivity.

MATERIALS AND METHODS

A hemorrhage shock model was established by using a controlled hemorrhage through the femoral artery that maintained a mean arterial pressure of 40 ± 2 mmHg for 3 h. MLD and mesenteric lymph duct ligation (MLDL) were performed from 1 to 3 h during hypotension. The papillary muscles of the heart were collected for measurement of calmodulin expression and for determining contractile responses to either isoprenaline or calcium.

RESULTS

The results showed that either MLD or MLDL reversed the hemorrhagic shock-induced downregulation of calmodulin expression, a marker protein of cardiomyocyte calcium sensitization, in papillary muscles. MLD also improved the decreased contractile response and ±df/dt of the papillary muscle strip to gradient isoprenaline or calcium caused by hemorrhagic shock.

CONCLUSION

These findings indicate that increased cardiac contractibility may be associated with the restoration of calcium sensitivity produced by PHSML drainage.

The Hepatoprotective mechanisms of 17β-estradiol after traumatic brain injury in male rats: Classical and non-classical estrogen receptors

Protective effects of estrogen (E2) on traumatic brain injury (TBI) have been determined. In this study, the hepatoprotective effects of E2 after TBI through its receptors and oxidative stress regulation have been evaluated. Diffuse TBI induced by the Marmarou method in male rats. G15, PHTPP, MPP, and ICI182-780 as selective antagonists of E2 were injected before TBI. The results indicated that TBI induces a significant increase in liver enzymes [Alkaline phosphatase (ALP), Aspartate aminotransferase (AST), Alanine aminotransferase (ALT), Glutamyl transferase (GGT)], and oxidants levels [Malondialdehyde (MDA), Nitric oxide (NO)] and decreases in antioxidant biomarkers [Glutathione peroxidase (GPx) and Superoxide dismutase (SOD)] in the brain and liver, and plasma. We also found that E2 significantly preserved levels of these biomarkers and enzymatic activity. All antagonists inhibited the effects of E2 on increasing SOD and GPx. Also, the effects of E2 on brain MDA levels were inhibited by all antagonists, but in the liver, only ICI + G15 + E2 + TBI group was affected. The impacts of E2 on brain and liver and plasma NO levels were inhibited by all antagonists. The current findings demonstrated that E2 probably improved liver injury after TBI by modulating oxidative stress. Also, both classic (ERβ, ERα) and non-classic [G protein-coupled estrogen receptor (GPER)] receptors are affected in the protective effects of E2.

Estrogen Enhances The Microvascular Reactivity Through Rhoa-Rock Pathway In Female Mice During Hemorrhagic Shock

ABSTRACT

Vascular hypo-reactivity plays a critical role inducing organ injury during hemorrhagic shock. 17β-estradiol (E2) can induce vasodilation to increase blood flow in various vascular beds. This study observed whether E2 can restore vascular hypo-reactivity induced by hemorrhagic shock, and whether E2 effects are associated with RhoA - Rho kinase (ROCK)- myosin light chain kinase phosphatase (MLCP) pathway. The hemorrhagic shock model (40 ± 2 mmHg for 1 h, resuscitation for 4 h) was established in ovary intact sham operation (OVI), ovariectomized (OVX) and OVX plus E2 supplement female mice. Intestinal microvascular loop was used to assess blood flow in vivo, mRNA expression and vascular reactivity in vitro. Hemorrhagic shock significantly reduced norepinephrine microvascular reactivity. Decreased microvascular reactivity was exacerbated by OVX and reversed by E2 supplement. U-46619 (RhoA agonist) increased microvascular reactivity, and C3 transferase (an ADP ribosyl transferase that selectively induces RhoA ribosylation) or Y-27632 (ROCK inhibitor) inhibited sham mice microvascular reactivity. Similarly, U-46619 increased microvascular reactivity in OVI and OVX mice following hemorrhagic shock, which was abolished by Y-27632 or concomitant incubation of okadaic acid (OA) (MLCP inhibitor) and Y-27632. In OVX plus E2 supplement mice with hemorrhagic shock, Y-27632 inhibited microvascular reactivity, which was abolished by concomitant U-46619 application. Lastly, hemorrhagic shock remarkably decreased intestinal loop blood flow, RhoA and ROCK mRNA expressions in vascular tissues in OVX females, but not in OVI females, which were reversed by E2 supplement. These results indicate that estrogen improves microvascular reactivity during hemorrhagic shock, and RhoA-ROCK signaling pathway may mediate E2 effects.

Mild and Moderate Traumatic Brain Injury and Gender-Based Critical Care Outcomes

BACKGROUND

Traumatic brain injury (TBI) is a major contributor to death and complications. Previous studies have identified gender disparities among trauma patients. This study aims to examine the association between gender and outcomes in TBI patients.

STUDY DESIGN AND METHODS

Review of our trauma registry: Patients were classified into groups according to their gender. Demographics extracted from the registry included age, injury severity score (ISS), Glasgow Coma Score (GCS), head abbreviated injury score (AIS), and the presence of an epidural hematoma (EDH). The primary outcome was mortality; secondary outcomes included ICU length of stay (ICU-LOS), craniotomy rate, ventilator-associated pneumonia (VAP), and readmission rates. Significance was defined as p < 0.05.

RESULTS

Nine hundred and thirty-five patients with TBI were studied: 62.1% (n = 581) were male and 37.9% (n = 354) were female. There were no differences in GCS, ISS, and head AIS. Males were younger [53 (IQR 30-77) vs. 76 (IQR 49.25-84), p < 0.05] and were more likely to have an EDH (9.6% vs. 4.8%, p = 0.007). Males also had a longer median ICU-LOS [4 days (IQR 2-8) vs. 3 days (IQR 0-5), p < 0.05] and were significantly more likely to require a craniotomy (44.6% vs. 19.2%, p < 0.001). In addition, males were more likely to develop VAP (4.1% vs. 0.8%, p = 0.004). Predicted survival (79.2% vs. 72.9%) and actual mortality rates (4.5% vs. 4.5%) were similar in both genders (p > 0.05).

CONCLUSION

In the context of our study, male patients with TBI were significantly younger, were more likely to sustain an EDH, and were also more likely to require a craniotomy, but mortality rates between both genders were similar. The male gender was also associated with a significantly increased ICU-LOS and VAP.

Estrogen Alleviates Sex-Dependent Differences in Lung Bacterial Clearance and Mortality Secondary to Bacterial Pneumonia after Traumatic Brain Injury

Traumatic brain injury (TBI) is the leading cause of injury-related death and disability in patients under the age of 46 years. Survivors of the initial injury often endure systemic complications such as pulmonary infection, and Pseudomonas aeruginosa is one of the most common causes of nosocomial pneumonia in intensive care units. Female patients are less likely to develop secondary pneumonia after TBI, and pre-clinical studies have revealed a salutary role for estrogen after trauma. Therefore, we hypothesized that female mice would experience less mortality after post-TBI pneumonia with P. aeruginosa. We employed a mouse model of TBI followed by P. aeruginosa pneumonia. Male mice had greater mortality and impaired lung bacterial clearance after post-TBI pneumonia compared with female mice. This was confirmed as a difference in sex hormones, as oophorectomized wild-type mice had mortality and lung bacterial clearance similar to male mice. There were differences in tumor necrosis factor-α secretion in male and female alveolar macrophages after P. aeruginosa infection. Finally, injection of male or oophorectomized wild-type female mice with estrogen restored lung bacterial clearance and prevented mortality. Our model of TBI followed by P. aeruginosa pneumonia is among the first to reveal sex dimorphism in secondary, long-term TBI complications.

Engagement of Posthemorrhagic Shock Mesenteric Lymph on CD4+ T Lymphocytes In Vivo and In Vitro

BACKGROUND

Immune dysfunction is associated with posthemorrhagic shock mesenteric lymph (PHSML) return. To determine the proliferation and cytokine production capacity of CD4⁺ T lymphocytes, the effect of PHSML drainage on spleen CD4⁺ T lymphocytes in a mouse model of hemorrhagic shock was assessed.

METHODS

The normal spleen CD4⁺ T lymphocytes were in vitro incubated with either drained normal mesenteric lymph (NML), PHSML during hypotension (PHSML-H), or PHSML from 0 h to 3 h after resuscitation (PHSML-R) to verify direct proliferation effects of PHSML.

RESULTS

Hemorrhagic shock led to reduction of proliferation and mRNA expression of interleukin 2 (IL-2) and IL-2 receptor in CD4⁺ T lymphocytes and to decrease in IL-2 and interferon γ (IFN-γ) levels in supernatants. In contrast, the interleukin-4 levels were increased. These effects were reversed by PHSML drainage. Moreover, NML incubation promoted CD4⁺ T lymphocyte proliferation, whereas both PHSML-H and PHSML-R treatment had a biphasic effects on CD4⁺ T lymphocyte proliferation, exhibiting an enhanced effect at early stages and an inhibitory effect at later stages. Compared with NML, PHSML-H increased IL-2 expression at 12 h, but decreased expression of both IL-2 and IFN-γ at 24 h. By contrast, PHSML-R induced significant increases in IL-2 and IFN-γ levels at 24 h. Interleukin-4 expression in CD4⁺ T lymphocytes was reduced at 12 h, but augmented at 24 h after incubation with either PHSML-H or PHSML-R.

CONCLUSIONS

The results indicate that PHSML has a direct inhibitory effect on CD4⁺ T lymphocyte proliferation that induces an inflammatory response, which is associated with cellular immune dysfunction.

Sex-Based Differences in Inpatient Burn Mortality

BACKGROUND

Among burn patients, research is conflicted, but may suggest that females are at increased risk of mortality, despite the opposite being true in non-burn trauma. Our objective was to determine whether sex-based differences in burn mortality exist, and assess whether patient demographics, comorbid conditions, and injury characteristics explain said differences.

METHODS

Adult patients admitted with burn injury-including inhalation injury only-between 2004 and 2013 were included. Inverse probability of treatment weights (IPTW) and inverse probability of censor weights (IPCW) were calculated using admit year, patient demographics, comorbid conditions, and injury characteristics to adjust for potential confounding and informative censoring. Standardized Kaplan-Meier survival curves, weighted by both IPTW and IPCW, were used to estimate the 30-day and 60-day risk of inpatient mortality across sex.

RESULTS

Females were older (median age 44 vs. 41 years old, p < 0.0001) and more likely to be Black (32% vs. 25%, p < 0.0001), have diabetes (14% vs. 10%, p < 0.0001), pulmonary disease (14% vs. 7%, p < 0.0001), heart failure (4% vs. 2%, p = 0.001), scald burns (45% vs. 26%, p < 0.0001), and inhalational injuries (10% vs. 8%, p = 0.04). Even after weighting, females were still over twice as likely to die after 60 days (RR 2.87, 95% CI 1.09, 7.51).

CONCLUSION

Female burn patients have a significantly higher risk of 60-day mortality, even after accounting for demographics, comorbid conditions, burn size, and inhalational injury. Future research efforts and treatments to attenuate mortality should account for these sex-based differences. The project was supported by the National Institutes of Health, Grant Number UL1TR001111.

Neuroendocrine Modulation of the Immune Response after Trauma and Sepsis: Does It Influence Outcome?

Although the treatment of multiple-injured patients has been improved during the last decades, sepsis and multiple organ failure (MOF) still remain the major cause of death. Following trauma, profound alterations of a large number of physiological systems can be observed that may potentially contribute to the development of sepsis and MOF. This includes alterations of the neuroendocrine and the immune system. A large number of studies focused on posttraumatic changes of the immune system, but the cause of posttraumatic immune disturbance remains to be established. However, an increasing number of data indicate that the bidirectional interaction between the neuroendocrine and the immune system may be an important mechanism involved in the development of sepsis and MOF. The aim of this article is to highlight the current knowledge of the neuroendocrine modulation of the immune system during trauma and sepsis.

Histone Deacetylase Inhibitors: A Novel Strategy in Trauma and Sepsis

Trauma remains a leading cause of morbidity and mortality among all age groups in the United States. Hemorrhagic shock and traumatic brain injury (TBI) are major causes of preventable death in trauma. Initial treatment involves fluid resuscitation to improve the intravascular volume. Although crystalloids may provide volume expansion, they do not have any pro-survival properties. Furthermore, aggressive fluid resuscitation can provoke a severe inflammatory response and worsen clinical outcomes. Due to logistical constraints, however, definitive resuscitation with blood products is often not feasible in the prehospital setting-highlighting the importance of adjunctive therapies. In recent years, histone deacetylase inhibitors (HDACis) have shown promise as pharmacologic agents for use in both trauma and sepsis. In this review, we discuss the role of histone deacetylases (HDACs) and pharmacologic agents that inhibit them (HDACis). We also highlight the therapeutic effects and mechanisms of action of HDACis in hemorrhagic shock, TBI, polytrauma, and sepsis. With further investigation and translation, HDACis have the potential to be a high-impact adjunctive therapy to traditional resuscitation.

Measurement of compensatory reserve predicts racial differences in tolerance to simulated hemorrhage in women

BACKGROUND

The compensatory reserve measurement (CRM) has been established to accurately measure the body's total integrated capacity to compensate for physiologic states of reduced central blood volume and predict hemodynamic decompensation associated with inadequate tissue oxygenation. We previously demonstrated that African American (AA) women have a higher tolerance to reductions in central blood volume. Therefore, we tested the hypothesis that the CRM would identify racial differences during simulated hemorrhage, before the onset of traditional signs/symptoms.

METHODS

We performed a retrospective analysis during simulated hemorrhage using lower-body negative pressure (LBNP) in 23 AA (22 ± 1 years; 24 ± 1 kg/m) and 31 white women (WW) (20 ± 1 years; 23 ± 1 kg/m). Beat-by-beat blood pressure (BP) and heart rate (HR) were recorded during progressive lower body negative pressure to presyncope. The BP waveforms were analyzed using a machine-learning algorithm to derive the CRM at each lower body negative pressure stage.

RESULTS

Resting mean arterial BP (AA, 78 ± 3 mm Hg vs. WW, 74 ± 2 mm Hg) and HR (AA, 68 ± 2 bpm vs. WW, 65 ± 2 bpm) were similar between groups. The CRM progressively decreased during LBNP in both groups; however, the rate of decline in the CRM was less (p < 0.05) in AA. The CRM was 4% higher in AA at -15 mm Hg LBNP and progressively increased to 21% higher at -50 mm Hg LBNP (p < 0.05). However, changes in BP and HR were not different between groups.

CONCLUSION

These data support the notion that the greater tolerance to simulated hemorrhage induced by LBNP in AA women can be explained by their greater capacity to protect the reserve to compensate for progressive central hypovolemia compared with WW, independent of standard vital signs.

LEVEL OF EVIDENCE

Diagnostic test, level II.

Chinese yam extract and adenosine attenuated LPS-induced cardiac dysfunction by inhibiting RAS and apoptosis via the ER-mediated activation of SHC/Ras/Raf1 pathway

PURPOSE

This study aimed to examine the effects of the Chinese yam extract and adenosine on lipopolysaccharide (LPS)-induced cardiac anomalies and the underlying mechanisms involved.

METHODS

Chinese yam extract [1630 mg/kg, intragastric (i.g.), 2 times/day] and adenosine (50 mg/kg, i.g., 2 times/day) were administered for 3 days, followed by the induction of sepsis by injecting LPS intraperitoneally [10 mg/kg, 2 h prior, intraperitoneally (i.p.)]. Also, estrogen receptor (ER)-unspecific antagonist Faslodex (ICI182,780, 0.5 mg/kg, i.p.) was administered 30 min before the treatments of Chinese yam extract or adenosine to evaluate whether the observed effects elicited by yam and adenosine were mediated via ERs. The heart function and the levels of pro-inflammatory cytokines, reversed mitogen-activated protein kinases (MAPKs), renin-angiotensin system (RAS), apoptosis markers, ER, and SHC/Ras/Raf1 were examined. The antagonistic effect of ICI182,780 (1 μM) and FTS (1 μM) against the Chinese yam extract (0.1 mg/ml) and adenosine (5 μM) in LPS (20 μg/ml, 24 h)-induced H9c2 cells was also investigated.

RESULTS

The Chinese yam extract and adenosine improved heart function, downregulated pro-inflammatory cytokines, reversed MAPK and RAS, transformed the apoptosis markers, and increased the expression of ER and SHC/Ras/Raf1 following LPS challenge. These effects could be blocked by ICI182,780. FTS could not block the expression of ER on the Chinese yam extract and adenosine interposed on LPS-induced H9c2 cells, demonstrating that ER might be the upstream signaling regulator of SHC/Ras/Raf1.

CONCLUSION

The Chinese yam extract and adenosine ameliorated LPS-induced cardiac contractility through the inhibition of RAS and apoptosis possibly via an ER-SHC/Ras/Raf1-dependent mechanism.

Anterior pituitary function in critical illness

Critical illness is hallmarked by major changes in all hypothalamic-pituitary-peripheral hormonal axes. Extensive animal and human studies have identified a biphasic pattern in circulating pituitary and peripheral hormone levels throughout critical illness by analogy with the fasting state. In the acute phase of critical illness, following a deleterious event, rapid neuroendocrine changes try to direct the human body toward a catabolic state to ensure provision of elementary energy sources, whereas costly anabolic processes are postponed. Thanks to new technologies and improvements in critical care, the majority of patients survive the acute insult and recover within a week. However, an important part of patients admitted to the ICU fail to recover sufficiently, and a prolonged phase of critical illness sets in. This prolonged phase of critical illness is characterized by a uniform suppression of the hypothalamic-pituitary-peripheral hormonal axes. Whereas the alterations in hormonal levels during the first hours and days after the onset of critical illness are evolutionary selected and are likely beneficial for survival, endocrine changes in prolonged critically ill patients could be harmful and may hamper recovery. Most studies investigating the substitution of peripheral hormones or strategies to overcome resistance to anabolic stimuli failed to show benefit for morbidity and mortality. Research on treatment with selected and combined hypothalamic hormones has shown promising results. Well-controlled RCTs to corroborate these findings are needed.

Blockade of Stellate Ganglion Remediates Hemorrhagic Shock-Induced Intestinal Barrier Dysfunction

BACKGROUND

Acute hemorrhage-induced excessive excitation of sympathetic-adrenal-medullary system (SAS) leads to gut hypoperfusion and barrier dysfunction, which is a critical event during hemorrhagic shock-induced multiple organ injury. Stellate ganglion blockade (SGB) has been widely used for suppression of sympathetic-adrenal-medullary system in the clinical practice. However, whether SGB improves intestinal barrier function after hemorrhagic shock remains unclear. Here, we hypothesized that the implementation of SGB restores intestinal barrier function and reduces gut injury.

MATERIALS AND METHODS

Male rats received the SGB pretreatment and underwent hemorrhagic shock followed by resuscitation. The 96-h survival rate, intestinal permeability and morphology, D-lactic acid concentration and diamine oxidase activity in plasma, and expressions of F-actin, Claudin-1, and E-cadherin in intestinal tissues were observed.

RESULTS

Pretreatment with SGB significantly enhances the 96-h survival rate in rats subjected to hemorrhagic shock (from 8.3% to 66.7%). Hemorrhagic shock reduced the coverage scale of intestinal mucus and intestinal villus width and height, enhanced the intestinal permeability to fluorescein isothiocyanate-dextran 4 and D-lactic acid concentration in plasma, and decreased the expressions of F-actin, Claudin-1, and E-Cadherin in intestinal tissue. These hemorrhagic shock-induced adverse effects were abolished by SGB treatment.

CONCLUSIONS

SGB treatment has a beneficial effect during hemorrhagic shock, which is associated with the improvement of intestine barrier function. SGB may be considered as a new therapeutic strategy for treatment of hemorrhagic shock.

Gender differences in response to abdominal compartment syndrome in rats

Objective

Our study aims to emphasize the novelty of female rats in regard to their hemodynamic changes in response to abdominal compartment syndrome. A group of 64 rats was randomly divided into 4 subgroups for each gender. Except for the control, intra-abdominal pressure was increased to 10, 20, 30 mmHg. Survival time, mean arterial pressure, pH and lactate were determined at different time intervals.

Results

As IAP was 20 mmHg, a statistically difference was seen between the male group and the female group starting from 15 min (126 ± 9.7 mmHg, 124 ± 14.7 mmHg respectively, p < 0.02) and lasting 2 h. At 30 mmHg, a statistically difference was seen between 30 to 60 min (p < 0.05). Only group 2 presented results with statistical power both at 30 and at 60 min concerning pH (p = 0.003, p < 0.001 respectively). In the lactate measurements at IAP of 10 mmHg, at 60 min male lactate level was 3.93 ± 1.13 and 2.25 ± 0.33 in female rats (p = 0.034). Female rats that were subjected to IAP of 20 mmHg and 30 mmHg had significantly better survival than male rats that were subjected to the same pressure (p < 0.05 and p < 0.01, respectively). We concluded that female rats have better preserved their hemodynamic and metabolic parameters during ACS than male rats.

Comparison of clinical characteristics and outcomes of pyogenic liver abscess patients < 65 years of age versus ≥ 65 years of age

Background

Pyogenic liver abscess (PLA) in the elderly is insufficiently elucidated. A few studies attempted to investigate the role of age in PLA have yielded controversial results. The purpose of this study was to explore the possible differences in the comorbidity, microbiological characteristics and clinical course between elderly and young PLA patients.

Methods

The clinical data of 332 adult PLA patients who received treatment at our hospital from January 2010 to December 2016 were collected. The demographic data, etiologies, comorbidities, clinical features, laboratory results, imaging findings, microbiological characteristics, choices of treatment and clinical outcomes were analyzed.

Results

Eighty-two (24.7%) patients were older than 65 years. Comorbidities including hypertension, diabetes mellitus, and cholelithiasis were more frequently found in older patients. Elderly PLA patients were more likely to present with atypical symptoms and signs on admission. The laboratory abnormalities and imaging findings were similar between the two groups. Klebsiella pneumonia was the most common pathogen on pus culture in both groups. There were no statistically significant differences in choices of treatment, PLA-related complications and length of in-hospital stay between the two groups. And there was no in-hospital mortality.

Conclusions

The clinical characteristics were similar in young and elderly PLA patients. However, elderly PLA patients were more likely to have underlying diseases and tended to have atypical presentations. Physicians need to be vigilant when encounter possible elderly patients with PLA. However, older PLA patients had comparable outcomes as their younger counterparts. With effective treatment, both elderly and young PLA patients can be cured.

Is there an association between female gender and outcome in severe trauma? A multi-center analysis in the Netherlands

INTRODUCTION

Little evidence suggest that female gender is associated with a lower risk of mortality in severely injured patients, especially in premenopausal women. Previous clinical studies have shown contradictory results regarding protective effects of gender on outcome after severe trauma. The objective of this study was to determine the association between gender and outcome (mortality and Intensive Care Unit (ICU) admission) among severely injured patients in the Netherlands.

METHODS

A retrospective multicentre study was performed including all polytrauma patients (Injury Severity Score (ISS) ≥16) admitted to the ED of three level 1 trauma centres, between January 1st, 2006 and December 31st, 2014. Data on age, gender, mechanism of injury, ISS, Abbreviated Injury Scale (AIS), prehospital intubation, Revised Trauma Score (RTS), systolic blood pressure (SBP) and Glasgow Coma Scale (GCS) upon admission at the Emergency Department was collected from three Regional Trauma Registries. To determine whether gender was an independent predictor of mortality and ICU admission, logistic regression analysis was performed.

RESULTS

Among 6865 trauma patients, male patients had a significantly higher ISS compared to female patients (26.3 ± 10.2 vs 25.3 ± 9.7, P = < 0.0001). Blunt trauma was significantly more common in the female group (95.2% vs 92.3%, P = < 0.0001). Males aged 16- to 44-years had a significant higher in-hospital mortality rate (10.4% vs 13.4%, P = 0.046). ICU admission rate was significantly lower in females (49.3% vs 54.5%, P = < 0.0001). In the overall group, logistic regression did not show gender as an independent predictor for in-hospital mortality (OR 1.020 (95% CI 0.865-1.204), P = 0.811) or mortality within 24 h (OR 1.049 (95% CI 0.829-1.327), P = 0.693). However, male gender was associated with an increased likelihood for ICU admission in the overall group (OR 1.205 (95% CI 1.046-1.388), P = 0.010).

CONCLUSION

The current study shows that in this population of severely injured patients, female sex is associated with a lower in-hospital mortality rate among those aged 16- to 44-years. Furthermore, female sex is independently associated with an overall decreased likelihood for ICU admission. More research is needed to examine the physiologic background of this protective effect of female sex in severe trauma.

Plasma metabolomics pilot study suggests age and sex-based differences in the metabolic response to traumatic injury

INTRODUCTION

Age and sex affect outcomes from trauma. Older patients tend to be under-triaged, consume more healthcare resources, and experience worse outcomes relative to younger patients. Sex has also been associated with different outcomes, with women experiencing better outcomes than men. While baseline metabolism differs with both age and sex, no study has examined how these differences affect the response to trauma. We used high-throughput metabolomics to assess metabolic differences associated with blunt trauma according to age and sex.

METHODS

Metabolic profiles were constructed using nuclear magnetic resonance spectroscopy for trauma patients age 21-40 years (n = 20, 55% male) and >65 years (n = 22, 41% male) from plasma samples obtained on Day 1 and Day 3 of each patient's hospital stay. These were compared to profiles constructed from plasma obtained from healthy controls of the same age (21-40: n = 23, 61% male; 65+: n = 26, 50% male). Differences in metabolic profiles were assessed with partial least squares discriminant analysis.

RESULTS

Trauma elicits an overwhelming global stress response that includes more subtle differences in metabolism related to age and gender. Significant differences due to normal aging were also identified. Many of the metabolites measured were present in similar levels in healthy controls age 65+ as they were in trauma patients of all ages. Sex-based differences in metabolism were observed in younger trauma patients on Day 3 but not in older patients.

CONCLUSIONS

Differences in energy metabolism and oxidative stress were implicated in the response to trauma in all patients. Older trauma patients may enter the trauma state with pre-existing oxidative stress and energy deficits that complicate recovery. Sex-based differences in recovery from trauma support the large body of work demonstrating the role of sex in recovery from trauma.

Gender differences in trauma, shock and sepsis

Despite efforts in prevention and intensive care, trauma and subsequent sepsis are still associated with a high mortality rate. Traumatic injury remains the main cause of death in people younger than 45 years and is thus a source of immense social and economic burden. In recent years, the knowledge concerning gender medicine has continuously increased. A number of studies have reported gender dimorphism in terms of response to trauma, shock and sepsis. However, the advantageous outcome following trauma-hemorrhage in females is not due only to sex. Rather, it is due to the prevailing hormonal milieu of the victim. In this respect, various experimental and clinical studies have demonstrated beneficial effects of estrogen for the central nervous system, the cardiopulmonary system, the liver, the kidneys, the immune system, and for the overall survival of the host. Nonetheless, there remains a gap between the bench and the bedside. This is most likely because clinical studies have not accounted for the estrus cycle. This review attempts to provide an overview of the current level of knowledge and highlights the most important organ systems responding to trauma, shock and sepsis. There continues to be a need for clinical studies on the prevailing hormonal milieu following trauma, shock and sepsis.