Beta-blocker exposure in the absence of significant head injuries is associated with reduced mortality in critically ill patients

Understanding Acquired Brain Injury: A Review

Any type of brain injury that transpires post-birth is referred to as Acquired Brain Injury (ABI). In general, ABI does not result from congenital disorders, degenerative diseases, or by brain trauma at birth. Although the human brain is protected from the external world by layers of tissues and bone, floating in nutrient-rich cerebrospinal fluid (CSF); it remains susceptible to harm and impairment. Brain damage resulting from ABI leads to changes in the normal neuronal tissue activity and/or structure in one or multiple areas of the brain, which can often affect normal brain functions. Impairment sustained from an ABI can last anywhere from days to a lifetime depending on the severity of the injury; however, many patients face trouble integrating themselves back into the community due to possible psychological and physiological outcomes. In this review, we discuss ABI pathologies, their types, and cellular mechanisms and summarize the therapeutic approaches for a better understanding of the subject and to create awareness among the public.

Beta-blockade is not associated with improved outcomes in isolated severe extracranial injury: an observational cohort study

Background

There is evidence supporting the use of beta-blockade in patients with traumatic brain injury. The reduction in sympathetic drive is thought to underlie the relationship between beta-blockade and increased survival. There is little evidence for similar effects in extracranial injuries. This study aimed to assess the association between beta-blockade and survival in patients suffering isolated severe extracranial injuries.

Methods

Patients treated at an academic urban trauma centre during a 5-year period were retrospectively identified. Adults suffering isolated severe extracranial injury [Injury Severity Score (ISS) ≥ 16 with Abbreviated Injury Score of ≤ 2 for any intracranial injury] were included. Patient characteristics and outcomes were collected from the trauma registry and hospital medical records. Patients were subdivided into beta-blocker exposed and unexposed groups. Patients were matched using propensity score matching. Differences were assessed using McNemar’s or paired Student’s t test. The primary outcome of interest was 90-day mortality and secondary outcome was in-hospital complications.

Results

698 patients were included of whom 10.5% were on a beta-blocker. Most patients suffered blunt force trauma (88.5%) with a mean [standard deviation] ISS of 24.6 [10.6]. Unadjusted mortality was higher in patients receiving beta-blockers (34.2% vs. 9.1%, p < 0.001) as were cardiac complications (8.2% vs. 1.4%, p = 0.002). Patients on beta-blockers were significantly older (69.5 [14.1] vs. 43.2 [18.0] years) and of higher comorbidity. After matching, no statistically significant differences were seen in 90-day mortality (34.2% vs. 30.1%, p = 0.690) or in-hospital complications.

Conclusions

Beta-blocker therapy does not appear to be associated with improved survival in patients with isolated severe extracranial injuries.

Beta-Blocker Therapy Is Associated With Increased 1-Year Survival After Hip Fracture Surgery: A Retrospective Cohort Study

The high mortality rates seen within the first postoperative year after hip fracture surgery have remained relatively unchanged in many countries for the past 15 years. Recent investigations have shown an association between beta-blocker (BB) therapy and a reduction in risk-adjusted mortality within the first 90 days after hip fracture surgery. We hypothesized that preoperative, and continuous postoperative, BB therapy may also be associated with a decrease in mortality within the first year after hip fracture surgery.

Retrospective cohort study of health service use for cardiovascular disease among adults with and without a record of injury hospital admission

OBJECTIVE

To quantify postinjury cardiovascular-related health service use experienced by mid to older aged adults hospitalised for injury, compared with uninjured adults. Additionally, to explore the effect of beta-blocker medications on postinjury cardiovascular hospitalisations among injury patients, given the potential cardioprotective effects of beta blockers.

DESIGN

A retrospective cohort study using linked administrative and survey data.

PARTICIPANTS

Records of 35 026 injured and 60 823 uninjured matched adults aged over 45 from New South Wales, Australia, who completed the 45 and up survey.

PRIMARY AND SECONDARY OUTCOME MEASURES

Admission rates and cumulative lengths of stay for cardiovascular hospitalisations, and prescription rates for cardiovascular medications. Negative binomial and Cox proportional hazards regression modelling were used to generate incident rate ratios (IRRs) and HR.

RESULTS

Compared with the uninjured, those with injury had a 19% higher adjusted rate of postinjury cardiovascular admissions (IRR 1.19, 95% CI 1.14 to 1.25), spent 40% longer in hospital for ardiovascular disease (IRR 1.40, 95% CI 1.26 to 1.57) and had slightly higher cardiovascular prescription rates (IRR 1.04, 95% CI 1.02 to 1.06), during study follow-up. Those in the injury cohort that used beta blockers both prior to and after injury (continuous) appeared to have reduced need for post-injury cardiovascular hospitalisation (IRR 1.09, 95% CI 1.17 to 1.42) compared with those commencing on beta blockers after injury (after 30 days: IRR 1.69, 95% CI 1.37 to 2.08).

CONCLUSIONS

Apparent increased postinjury hospitalisation rates and prolonged length of stay related to cardiovascular disease suggest that injury patients may require clinical support for an extended period after injury. Additionally, injury patients who were on continuous beta blocker treatment appeared to have lower need for post-injury cardiovascular hospitalisations. However, the data do not allow us to draw clear conclusions and further clinical research is required.

β-adrenergic blockade is associated with a reduced risk of 90-day mortality after surgery for hip fractures

Background

There is a significant postoperative mortality risk in patients subjected to surgery for hip fractures. Adrenergic hyperactivity induced by trauma and subsequent surgery is thought to be an important contributor. By downregulating the effect of circulating catecholamines the increased risk of postoperative mortality may be reduced. The aim of the current study is to assess the association between regular β-blocker therapy and postoperative mortality.

Methods

This cohort study used the prospectively collected Swedish National Quality Registry for hip fractures to identify all patients over 40 years of age subjected to surgery for hip fractures between 2013 and 2017 in Örebro County, Sweden. Patients with ongoing β-blocker therapy at the time of surgery were allocated to the β-blocker-positive cohort. The primary outcome of interest was 90-day postoperative mortality. Risk factors for 90-day mortality were evaluated using Poisson regression analysis.

Results

A total of 2443 patients were included in this cohort of whom 900 (36.8%) had ongoing β-blocker therapy before surgery. The β-blocker positive group was significantly older, less fit for surgery based on their American Society of Anesthesiologists classification and had a higher prevalence of comorbidities. A significant risk reduction in 90-day mortality was detected in patients receiving β-blockers (adjusted incidence rate ratio=0.82, 95% CI 0.68 to 0.98, p=0.03).

Conclusions

β-blocker therapy is associated with a significant reduction in 90-day postoperative mortality after hip fracture surgery. Further investigation into this finding is warranted.

Level of evidence

Therapeutic study, level III; prognostic study, level II.

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.

Beta-blocker Therapy is Associated with Decreased 1-year Mortality After Emergency Laparotomy in Geriatric Patients

Background and Aims:

Emergency laparotomy is associated with a great risk of mortality in the elderly. The hyperadrenergic state induced by surgical trauma may play an important role in the pathophysiology of this increased risk. Studies have shown that beta-blocker exposure may be associated with decreased morbidity and mortality in the perioperative period. We aimed to study the effect of beta-blocker on mortality in geriatric patients undergoing emergency laparotomy.

Material and Methods:

This is a retrospective study of patients who underwent emergency laparotomy between 1 January 2015 and 31 December 2016 at a single institution. The outcomes of interest were the association between post-operative complications and in-hospital and 1-year mortality in patients on beta-blocker therapy (BB(+)) and those who were not (BB(−)). The Poisson regression analysis was used to evaluate the association.

Results:

A total of 192 patients were included of whom 62 (32.2%) had pre-operative beta-blocker therapy with continued exposure during their hospital stay. The in-hospital mortality was 17.7% in the BB(+) and 23.8% in the BB(−) cohorts ( p = 0.441). One-year mortality was significantly lower in the BB(+) group compared to the BB(−) group (30.6% versus 47.7%; p = 0.038). After adjusting for confounders, the incidence of deaths during 1 year post-operatively decreased by 35% in the BB(+) group (incidence rate ratio = 0.65, p = 0.004). No significant differences in the incidence of post-operative complications between the two groups could be measured.

Conclusion:

Beta-blocker therapy may be associated with reduced 1-year mortality following emergency laparotomy in geriatric patients.

Effect of preadmission beta-blockade on mortality in multiple trauma

Background

High levels of circulating catecholamines after multiple trauma have been associated with increased morbidity and mortality. Beta‐adrenergic receptor antagonist (beta‐blocker) therapy has emerged as a potential treatment option, but the effect of preinjury beta‐blockade on trauma‐induced mortality is unclear. The aim of this study was to assess whether preinjury beta‐blocker therapy is associated with reduced mortality after multiple trauma.

Methods

Severely injured patients, aged at least 50 years, admitted to a level one trauma centre over a 10‐year interval were linked to national and local registries of co‐morbidities, prescription drug use and level of education. The association between preinjury beta‐blocker use and 30‐day mortality was explored using logistic regression analysis.

Results

Some 1376 patients were included; 338 (24·6 per cent) were receiving beta‐blockers at the time of trauma. Beta‐blocker users had an increased crude 30‐day mortality rate compared with that for non‐users: 32·8 versus 19·7 per cent respectively (P < 0·001). After adjustment for baseline imbalances and injury‐related factors, there was no association between preinjury beta‐blocker use and mortality (OR 1·09, 95 per cent c.i. 0·70 to 1·70). Separate analyses of individuals with or without severe head injury did not significantly change this association. There was no significant difference in the rate of shock between beta‐blocker users and non‐users.

Conclusion

Pretrauma beta‐blockade is not associated with 30‐day mortality beyond the effects of age, co‐morbidity and injury severity.

Effect of beta-blocker therapy on early mortality after emergency colonic cancer surgery

Background

Emergency colorectal cancer surgery is associated with significant mortality. Induced adrenergic hyperactivity is thought to be an important contributor. Downregulating the effects of circulating catecholamines may reduce the risk of adverse outcomes. This study assessed whether regular preoperative beta-blockade reduced mortality after emergency colonic cancer surgery.

Methods

This cohort study used the prospectively collected Swedish Colorectal Cancer Registry to recruit all adult patients requiring emergency colonic cancer surgery between 2011 and 2016. Patients were subdivided into those receiving regular beta-blocker therapy before surgery and those who were not (control). Demographics and clinical outcomes were compared. Risk factors for 30-day mortality were evaluated using Poisson regression analysis.

Results

A total of 3187 patients were included, of whom 685 (21·5 per cent) used regular beta-blocker therapy before surgery. The overall 30-day mortality rate was significantly reduced in the beta-blocker group compared with controls: 3·1 (95 per cent c.i. 1·9 to 4·7) versus 8·6 (7·6 to 9·8) per cent respectively (P &lt; 0·001). Beta-blocker therapy was the only modifiable protective factor identified in multivariable analysis of 30-day all-cause mortality (incidence rate ratio 0·31, 95 per cent c.i. 0·20 to 0·47; P &lt; 0·001) and was associated with a significant reduction in death of cardiovascular, respiratory, sepsis and multiple organ failure origin.

Conclusion

Preoperative beta-blocker therapy may be associated with a reduction in 30-day mortality following emergency colonic cancer surgery.

The effects of beta blockade and clonidine on persistent injury-associated anemia

BACKGROUND

Nonselective beta blockade (BB) and clonidine may abrogate catecholamine-mediated persistent injury-associated anemia. We hypothesized that critically ill trauma patients who received BB or clonidine would have favorable hemoglobin (Hb) trends when adjusting for operative blood loss (OBL), phlebotomy blood loss (PBL), and red blood cell (RBC) transfusion volumes, and that the effect would be greatest among the elderly, who have higher catecholamine levels.

METHODS

We performed a 4-y retrospective cohort analysis of 280 consecutive trauma patients with ICU stay ≥48 h and moderate/severe anemia. Patients who received BB or clonidine for ≥25% of their hospital stay were grouped as the BB/clonidine cohort (n = 84); all other patients served as controls (n = 196). Admission and discharge Hb were used to calculate ΔHb. OBL, PBL, and RBC volume were used to calculate adjusted ΔHb assuming 300 mL RBC = 1 g/dL Hb.

RESULTS

BB/clonidine and control patients had similar age, injury severity, comorbid illness, and admission Hb. BB/clonidine patients received fewer RBCs despite greater OBL, though neither association was statistically significant. BB/clonidine patients had higher discharge Hb (9.9 versus 9.5, P = 0.029) and adjusted ΔHb (+1.0 versus -0.8, P = 0.003). Hb curves separated after hospital day 10. The difference in adjusted ΔHb between groups increased with advanced age (all patients: 1.7, ≥50 y: 1.8, ≥60 y: 2.4, ≥70 y: 3.7).

CONCLUSIONS

Critically ill trauma patients receiving BB or clonidine had favorable Hb trends when accounting for OBL, PBL, and RBC transfusions. These findings support the hypothesis that BB and clonidine alleviate persistent injury-associated anemia, with strongest effects among the elderly.

β-Blockade use for Traumatic Injuries and Immunomodulation: A Review of Proposed Mechanisms and Clinical Evidence

Sympathetic nervous system activation and catecholamine release are important events following injury and infection. The nature and timing of different pathophysiologic insults have significant effects on adrenergic pathways, inflammatory mediators, and the host response. Beta adrenergic receptor blockers (β-blockers) are commonly used for treatment of cardiovascular disease, and recent data suggests that the metabolic and immunomodulatory effects of β-blockers can expand their use. β-blocker therapy can reduce sympathetic activation and hypermetabolism as well as modify glucose homeostasis and cytokine expression. It is the purpose of this review to examine either the biologic basis for proposed mechanisms or to describe current available clinical evidence for the use of β-blockers in traumatic brain injury, spinal cord injury, hemorrhagic shock, acute traumatic coagulopathy, erythropoietic dysfunction, metabolic dysfunction, pulmonary dysfunction, burns, immunomodulation, and sepsis.

Beta-blockers and Traumatic Brain Injury: A Systematic Review, Meta-analysis, and Eastern Association for the Surgery of Trauma Guideline

OBJECTIVE

To determine if beta-(β)-blockers improve outcomes after acute traumatic brain injury (TBI).

BACKGROUND

There have been no new inpatient pharmacologic therapies to improve TBI outcomes in a half-century. Treatment of TBI patients with β-blockers offers a potentially beneficial approach.

METHODS

Using MEDLINE, EMBASE, and CENTRAL databases, eligible articles for our systematic review and meta-analysis (PROSPERO CRD42016048547) included adult (age ≥ 16 years) blunt trauma patients admitted with TBI. The exposure of interest was β-blocker administration initiated during the hospitalization. Outcomes were mortality, functional measures, quality of life, cardiopulmonary morbidity (e.g., hypotension, bradycardia, bronchospasm, and/or congestive heart failure). Data were analyzed using a random-effects model, and represented by pooled odds ratio (OR) with 95% confidence intervals (CI) and statistical heterogeneity (I).

RESULTS

Data were extracted from 9 included studies encompassing 2005 unique TBI patients with β-blocker treatment and 6240 unique controls. Exposure to β-blockers after TBI was associated with a reduction of in-hospital mortality (pooled OR 0.39, 95% CI: 0.27-0.56; I = 65%, P < 0.00001). None of the included studies examined functional outcome or quality of life measures, and cardiopulmonary adverse events were rarely reported. No clear evidence of reporting bias was identified.

CONCLUSIONS

In adults with acute TBI, observational studies reveal a significant mortality advantage with β-blockers; however, quality of evidence is very low. We conditionally recommend the use of in-hospital β-blockers. However, we recommend further high-quality trials to answer questions about the mechanisms of action, effectiveness on subgroups, dose-response, length of therapy, functional outcome, and quality of life after β-blocker use for TBI.

Traumatic Endotheliopathy: A Prospective Observational Study of 424 Severely Injured Patients

Objective:

Investigate and confirm the association between sympathoadrenal activation, endotheliopathy and poor outcome in trauma patients.

Background:

The association between sympathoadrenal activation, endotheliopathy, and poor outcome in trauma has only been demonstrated in smaller patient cohorts and animal models but needs confirmation in a large independent patient cohort.

Methods:

Prospective observational study of 424 trauma patients admitted to a level 1 Trauma Center. Admission plasma levels of catecholamines (adrenaline, noradrenaline) and biomarkers reflecting endothelial damage (syndecan-1, thrombomodulin, and sE-selectin) were measured and demography, injury type and severity, physiology, treatment, and mortality up till 28 days were recorded.

Results:

Patients had a median ISS of 17 with 72% suffering from blunt injury. Adrenaline and noradrenaline correlated with syndecan-1 (r = 0.38, P < 0.001 and r = 0.23, P < 0.001, respectively) but adrenaline was the only independent predictor of syndecan-1 by multiple linear regression adjusted for age, injury severity score, Glascow Coma Scale, systolic blood pressure, base excess, platelet count, hemoglobin, prehospital plasma, and prehospital fluids (100 pg/mL higher adrenaline predicted 2.75 ng/mL higher syndecan-1, P < 0.001). By Cox analyses adjusted for age, sex, injury severity score, Glascow Coma Scale, base excess, platelet count and hemoglobin, adrenaline, and syndecan-1 were the only independent predictors of both <24-hours, 7-day and 28-day mortality (all P < 0.05). Furthermore, noradrenaline was an independent predictor of <24-hours mortality and thrombomodulin was an independent predictor of 7-day and 28-day mortality (all P < 0.05).

Conclusions:

We confirmed that sympathoadrenal activation was strongly and independently associated with endothelial glycocalyx and cell damage (ie, endotheliopathy) and furthermore that sympathoadrenal activation and endotheliopathy were independent predictors of mortality in trauma patients.

Syndecan-1: A Quantitative Marker for the Endotheliopathy of Trauma

BACKGROUND

Endothelial glycocalyx breakdown elicits syndecan-1 shedding and endotheliopathy of trauma (EoT). We hypothesized that a cutoff syndecan-1 level can identify patients with endothelial dysfunction who would have poorer outcomes.

STUDY DESIGN

We conducted a prospective observational study. Trauma patients with the highest level of activation admitted from July 2011 through September 2013 were eligible. We recorded demographics, injury type/severity (Injury Severity Score), physiology and outcomes data, and quantified syndecan-1 and soluble thrombomodulin from plasma with ELISAs. With receiver operating characteristic curve analysis, we defined EoT+ as the syndecan-1 cutoff level that maximized the sum of sensitivity and specificity (Youden index) in predicting 24-hour in-hospital mortality. We stratified by this cutoff and compared both groups. Factors associated with 30-day in-hospital mortality were assessed with multivariable logistic regression (adjusted odds ratios and 95% CIs reported).

RESULTS

From receiver operating characteristic curve analysis (area under the curve = 0.71; 95% CI 0.58 to 0.84), we defined EoT+ as syndecan-1 level ≥40 ng/mL (sensitivity = 0.62, specificity = 0.73). Of the 410 patients evaluated, 34% (n = 138) were EoT+ patients, who presented with higher Injury Severity Scores (p < 0.001) and blunt trauma frequency (p = 0.016) than EoT- patients. Although EoT+ patients had lower systolic blood pressure (median 119 vs 128 mmHg; p < 0.001), base excess and hemoglobin were similar between groups. The proportion of transfused (EoT+ 71.7% vs EoT- 36.4%; p < 0.001) and deceased EoT+ patients (EoT+ 24.6% vs EoT- 12.1%; p < 0.001) was higher. EoT+ was significantly associated with 30-day in-hospital mortality (adjusted odds ratio = 2.23; 95% CI 1.22 to 4.04).

CONCLUSIONS

A syndecan-1 level ≥40 ng/mL identified patients with significantly worse outcomes, despite admission physiology similar to those without the condition.

β-Blockers, Cocaine, and the Unopposed α-Stimulation Phenomenon

Cocaine abuse remains a significant worldwide health problem. Patients with cardiovascular toxicity from cocaine abuse frequently present to the emergency department for treatment. These patients may be tachycardic, hypertensive, agitated, and have chest pain. Several pharmacological options exist for treatment of cocaine-induced cardiovascular toxicity. For the past 3 decades, the phenomenon of unopposed α-stimulation after β-blocker use in cocaine-positive patients has been cited as an absolute contraindication, despite limited and inconsistent clinical evidence. In this review, the authors of the original studies, case reports, and systematic review in which unopposed α-stimulation was believed to be a factor investigate the pathophysiology, pharmacology, and published evidence behind the unopposed α-stimulation phenomenon. We also investigate other potential explanations for unopposed α-stimulation, including the unique and deleterious pharmacologic properties of cocaine in the absence of β-blockers. The safety and efficacy of the mixed β-/α-blockers labetalol and carvedilol are also discussed in relation to unopposed α-stimulation.

Impact of Beta-Blockers on Nonhead Injured Trauma Patients

Catecholamine surge after traumatic injury may lead to dysautonomia with increased morbidity. Small retrospective studies have shown potential benefit of beta-blockers (BB) in trauma patients with and without traumatic brain injury (TBI). This study evaluates a large multiply injured cohort without TBI that received BB. Patients were identified from the trauma registry from January 1, 2003 to December 31, 2011. Patients who received >1 dose of BB were compared to controls. Patients with TBI, length of stay (LOS) < 2 days, and prehospital BB were excluded. Outcomes were mortality, intensive care unit (ICU) LOS, and LOS. Stepwise multivariable regression was used to identify variables significantly associated with mortality. During the study period, 19,151 eligible patients were admitted. The mean age was 39 years. Most were male (74%) and most sustained blunt mechanism (75%). A total of 1854 (11%) patients received BB. BB patients had longer LOS (16 vs 6 days), ICU LOS (7 vs 1 days), and higher mortality (2.8 vs 0.5%) (all P < 0.001). Multivariable regression demonstrated no benefit to BB after adjusting for potential confounding characteristics [odds ratio (OR) 0.952; confidence interval (CI) 0.620–1.461]. In conclusion, in this largest study to date, patients receiving BB were older, more severely injured, and had a higher mortality. Unlike TBI patients, multivariable regression showed no benefit from BB in this population.

Sympathoadrenal activation and endothelial damage are inter correlated and predict increased mortality in patients resuscitated after out-of-hospital cardiac arrest. a post Hoc sub-study of patients from the TTM-trial

Objective

Sympathoadrenal activation and endothelial damage are hallmarks of acute critical illness. This study investigated their association and predictive value in patients resuscitated from out-of-hospital cardiac arrest (OHCA).

Methods

Post-hoc analysis of patients included at a single site in The Targeted Temperature Management at 33 degrees versus 36 degrees after Cardiac Arrest (TTM) trial. The main study reported similar outcomes with targeting 33 versus 36 degrees. TTM main study ClinicalTrials.gov: NCT01020916. One hundred sixty three patients resuscitated from OHCA were included at a single site ICU. Blood was sampled a median 135 min (Inter Quartile Range (IQR) 103-169) after OHCA. Plasma catecholamines (adrenaline, noradrenaline) and serum endothelial biomarkers (syndecan-1, thrombomodulin, sE-selectin, sVE-cadherin) were measured at admission (immediately after randomization). We had access to data on demography, medical history, characteristics of the OHCA, patients and 180-day outcome.

Results

Adrenaline and noradrenaline correlated positively with syndecan-1 and thrombomodulin i.e., biomarkers reflecting endothelial damage (both p<0.05). Overall 180-day mortality was 35%. By Cox analyses, plasma adrenaline, serum sE-selectin, reflecting endothelial cell activation, and thrombomodulin levels predicted mortality. However, thrombomodulin was the only biomarker independently associated with mortality after adjusting for gender, age, rhythm (shockable vs. non-shockable), OHCA to return of spontaneous circulation (ROSC) time, shock at admission and ST elevation myocardial infarction (30-day Hazards Ratio 1.71 (IQR 1.05-2.77), p=0.031 and 180-day Hazards Ratio 1.65 (IQR 1.03-2.65), p=0.037 for 2-fold higher thrombomodulin levels).

Conclusions

Circulating catecholamines and endothelial damage were intercorrelated and predicted increased mortality. Interventions aiming at protecting and/or restoring the endothelium may be beneficial in OHCA patients.

Impact of β-adrenoceptor blockade on systemic inflammation and coagulation disturbances in rats with acute traumatic coagulopathy

BACKGROUND

Sympathetic hyperactivity occurs early in acute traumatic coagulopathy (ATC) and is closely related to its development. β-adrenoceptor antagonists are known to alleviate adverse sympathetic effects and improve outcome in various diseases. We investigated whether β-blockers have protective effects against inflammation and endothelial and hemostatic disorders in ATC.

MATERIAL AND METHODS

ATC was induced in male Sprague-Dawley rats by trauma and hemorrhagic shock. Rats were randomly assigned to the sham, ATCC (ATC control), and ATCB (ATC with beta-adrenoceptor blockade) groups. Rats were injected intraperitoneally with propranolol or vehicle at baseline. Heart rate variability (HRV) and markers of inflammation, coagulation, and endothelial activation were measured, and Western blotting analysis of nuclear factor (NF)-κB was done after shock. Separate ATCC and ATCB groups were observed to compare overall mortality.

RESULTS

HRV showed enhanced sympathetic tone in the ATCC group, which was reversed by propranolol. Propranolol attenuated the induction of pro-inflammatory cytokines TNF-α and IL-6, as well as fibrinolysis markers plasmin antiplasmin complex and tissue-type plasminogen activator. The increased serum syndecan-1 and soluble thrombomodulin were inhibited by propranolol, and the NF-κB expression was also decreased by propranolol pretreatment. But propranolol did not alter overall mortality in rats with ATC after shock.

CONCLUSIONS

Beta-adrenoceptor blockade can alleviate sympathetic hyperactivity and exert anti-inflammatory, anti-fibrinolysis, and endothelial protective effects, confirming its pivotal role in the pathogenesis of ATC. Its mechanism in ATC should be explored further.

Perioperative beta-blockade: might the baby go out with the bath water?

Perioperative β-blocker therapy has been advocated to reduce cardiac mortality and morbidity in high-risk cardiac patients undergoing non-cardiac surgery. Core data that supported this intervention and informed international societal guidelines has recently been withdrawn. A subsequent meta-analysis of the remaining data reporting excess mortality has re-opened the debate about the utility of β-blocker therapy in the perioperative period. Criticism of remaining trial designs and new insights into the protective mechanisms of β-blocker therapy in critical illness raise important questions that should now be addressed by a further robust, high-quality randomised control trial.

Advances in the management of the critically injured patient in the operating room

Care of trauma patients continues to improve through better understanding of optimal timing of operating room (OR) interventions, improved monitoring for patients with head injury and hemodynamic compromise, optimization of volume status, and use of appropriate vasoactive agents. Investigation of the pathophysiology of trauma patients as they progress to the chronic phase continues to advance interventions in the ICU and the OR. This article is an evidence-based update of anesthetic considerations for these patients, including management of intracranial pressure, cardiac monitoring, management of the damage control abdomen, fluid and hemodynamic management, and control of coagulopathies.