Cortisol response to corticotropin stimulation in trauma patients: influence of hemorrhagic shock

Review article: Early steroid administration for traumatic haemorrhagic shock: A systematic review

Haemorrhagic shock after trauma is a leading cause of death worldwide, particularly in young individuals. Despite advances in trauma systems and resuscitation strategies, mortality from haemorrhagic shock has not declined over the previous two decades. A proportion of shocked trauma patients may experience a deficiency of cortisol relative to the severity of their injury. The benefit of exogenous steroid administration in patients suffering haemorrhagic shock as a result of injury is unclear. A systematic review of four databases (Ovid Medline, Ovid Embase, Cochrane, Scopus) was undertaken. Inclusion and exclusion criteria were pre-determined and two reviewers independently screened the articles with disagreements arbitrated by a third reviewer. The primary outcome variable was 28-day mortality. Quality of studies were assessed using the Cochrane-risk-of-bias (RoB 2) tool. Of the 2919 studies yielded by the search strategy, 1274 duplicates were removed and 1645 screened on title and abstract. After the full text of 33 studies were assessed, two articles were included. Both studies were over 30 years old with small numbers of participants and with primary outcomes not including mortality. Of the data available, no statistically significant difference in mortality was detected. Hospital length of stay, reversal of shock or adverse events were not reported. Both studies were at risk of bias. There are no high quality or recent studies in the English literature investigating the use of steroids for haemorrhagic shocked trauma patients. PROSPERO: CRD42021239656.

Danger signals in traumatic hemorrhagic shock and new lines for clinical applications

Hemorrhage is the leading cause of death in severe trauma injuries. When organs or tissues are subjected to prolonged hypoxia, danger signals-known as damage-associated molecular patterns (DAMPs)-are released into the intercellular environment. The endothelium is both the target and a major provider of damage-associated molecular patterns, which are directly involved in immuno-inflammatory dysregulation and the associated tissue suffering. Although damage-associated molecular patterns release begins very early after trauma, this release and its consequences continue beyond the initial treatment. Here we review a few examples of damage-associated molecular patterns to illustrate their pathophysiological roles, with emphasis on emerging therapeutic interventions in the context of severe trauma. Therapeutic intervention administered at precise points during damage-associated molecular patterns release may have beneficial effects by calming the inflammatory storm triggered by traumatic hemorrhagic shock.

Immune modulation after traumatic brain injury

Traumatic brain injury (TBI) induces instant activation of innate immunity in brain tissue, followed by a systematization of the inflammatory response. The subsequent response, evolved to limit an overwhelming systemic inflammatory response and to induce healing, involves the autonomic nervous system, hormonal systems, and the regulation of immune cells. This physiological response induces an immunosuppression and tolerance state that promotes to the occurrence of secondary infections. This review describes the immunological consequences of TBI and highlights potential novel therapeutic approaches using immune modulation to restore homeostasis between the nervous system and innate immunity.

Crosstalk between brain, lung and heart in critical care

Extracerebral complications, especially pulmonary and cardiovascular, are frequent in brain-injured patients and are major outcome determinants. Two major pathways have been described: brain-lung and brain-heart interactions. Lung injuries after acute brain damages include ventilator-associated pneumonia (VAP), acute respiratory distress syndrome (ARDS) and neurogenic pulmonary œdema (NPE), whereas heart injuries can range from cardiac enzymes release, ECG abnormalities to left ventricle dysfunction or cardiogenic shock. The pathophysiologies of these brain-lung and brain-heart crosstalk are complex and sometimes interconnected. This review aims to describe the epidemiology and pathophysiology of lung and heart injuries in brain-injured patients with the different pathways implicated and the clinical implications for critical care physicians.

Prospective evaluation of admission cortisol in trauma

Background

A low cortisol level has been shown to occur soon after trauma, and is associated with increased mortality. The purpose of this study was to investigate the impact of low cortisol levels in acute critically ill trauma patients. We hypothesized that patients would require increase vasopressor use, have a greater blood product administration, and increased mortality rate.

Methods

A blinded, prospective observational study was performed at an American College of Surgeons verified Level I trauma center. Adult patients who met trauma activation criteria, received initial treatment at Community Regional Medical Center and were admitted to the intensive care unit were included. Total serum cortisol levels were measured from the initial blood draw in the emergency department. Patients were categorized according to cortisol ≤15 µg/dL (severe low cortisol, SLC), 15.01–25 µg/dL (relative low cortisol, RLC), or >25 µg/dL (normal cortisol, NC) and compared on demographics, injury severity score, initial vital signs, blood product usage, vasopressor requirements, and mortality.

Results

Cortisol levels were ordered for 280 patients; 91 were excluded and 189 were included. Penetrating trauma accounted for 19% of injuries and blunt trauma for 81%. 22 patients (12%) had SLC, 83 (44%) had RLC, and 84 (44%) had NC. This study found patients with admission SLC had higher rates of vasopressor requirements, required more units of blood, and had a higher mortality rate than both the RLC and NC groups.

Conclusion

Low cortisol level can be identified acutely after severe trauma. Trauma patients with SLC had larger blood product requirements, vasopressor use, and increase mortality. Initial cortisol levels are useful in identifying these high-risk patients.

Level of evidence

Prognostic/epidemiologic study, level III

The blockade of corticotropin-releasing factor 1 receptor attenuates anxiety-related symptoms and hypothalamus-pituitary-adrenal axis reactivity in mice with mild traumatic brain injury

Recent studies have shown that mild traumatic brain injury (mTBI) is associated with higher risk for anxiety-related disorders. Dysregulation in the hypothalamus-pituitary-adrenal (HPA) axis following mTBI has been proposed to be involved in the development of neurobehavioral abnormalities; however, the underlying mechanisms are largely unknown. The aim of this study was to determine whether the corticotropin-releasing-factor-1 (CRF-1) receptor is involved in the regulation of anxiety-related symptoms in a mouse model of mTBI. Animals with or without mTBI received intracerebroventricular injections of a CRF-1 receptor agonist (CRF; 0.01 nmol/mouse) or antagonist (antalarmin; 1 µg/mouse) for 5 days, and then the animals were subjected to anxiety tests (light-dark box and zero maze). The levels of adrenocorticotropic hormone and corticosterone, the most important markers of HPA axis, were also measured after behavioral tests. Our results indicated that mTBI-induced anxiety-related symptoms in mice through increased levels of adrenocorticotropic hormone and corticosterone, showing HPA axis hyperactivity. Interestingly, activation of CRF receptor by a subthreshold dose of CRF resulted in significant increases in anxiety-like behaviors and HPA axis response to stress, whereas blockade of CRF receptors by a subthreshold dose of antalarmin decreased anxiety-related symptoms and HPA axis response to stress in mTBI-induced mice. Collectively, these findings suggest that the CRF-1 receptor plays an important role in the regulation of anxiety-related behaviors following mTBI induction in mice and support the hypothesis that blockade of the CRF-1 receptor may be a promising therapeutic target for anxiety-related disorders in patients with TBI.

Cortisol total/CRP ratio for the prediction of hospital-acquired pneumonia and initiation of corticosteroid therapy in traumatic brain-injured patients

BACKGROUND

To propose a combination of blood biomarkers for the prediction of hospital-acquired pneumonia (HAP) and for the selection of traumatic brain-injured (TBI) patients eligible for corticosteroid therapy for the prevention of HAP.

METHODS

This was a sub-study of the CORTI-TC trial, a multicenter, randomized, double-blind, controlled trial evaluating the risk of HAP at day 28 in 336 TBI patients treated or not with corticosteroid therapy. Patients were between 15 and 65 years with severe traumatic brain injury (Glasgow coma scale score ≤ 8 and trauma-associated lesion on brain CT scan) and were enrolled within 24 h of trauma. The blood levels of CRP and cortisoltotal&free, as a surrogate marker of the pro/anti-inflammatory response balance, were measured in samples collected before the treatment initiation. Endpoint was HAP on day 28.

RESULTS

Of the 179 patients with available samples, 89 (49.7%) developed an HAP. Cortisoltotal&free and CRP blood levels upon ICU admission were not significantly different between patients with or without HAP. The cortisoltotal/CRP ratio upon admission was 2.30 [1.25-3.91] in patients without HAP and 3.36 [1.74-5.09] in patients with HAP (p = 0.021). In multivariate analysis, a cortisoltotal/CRP ratio > 3, selected upon the best Youden index on the ROC curve, was independently associated with HAP (OR 2.50, CI95% [1.34-4.64] p = 0.004). The HR for HAP with corticosteroid treatment was 0.59 (CI95% [0.34-1.00], p = 0.005) in patients with a cortisoltotal/CRP ratio > 3, and 0.89 (CI95% [0.49-1.64], p = 0.85) in patients with a ratio < 3.

CONCLUSION

A cortisoltotal/CRP ratio > 3 upon admission may predict the development of HAP in severe TBI. Among these patients, corticosteroids reduce the occurrence HAP. We suggest that this ratio may select the patients who may benefit from corticosteroid therapy for the prevention of HAP.

Anesthesia for Trauma Patients

An improved understanding of the pathophysiology of combat trauma has evolved over the past decade and has helped guide the anesthetic care of the trauma patient requiring surgical intervention. Trauma anesthesia begins before patient arrival with warming of the operating room, preparation of anesthetic medications and routine anesthetic machine checks. Induction of anesthesia must account for potential hemodynamic instability and intubation must consider airway trauma. Maintenance of anesthesia is accomplished with anesthetic gas, intravenous infusions or a combination of both. Resuscitation must precede or be ongoing with the maintenance of anesthesia. Blood product transfusion, antibiotic administration, and use of pharmacologic adjuncts (e.g., tranexamic acid, calcium) all occur simultaneously. Ventilatory strategies to mitigate lung injury can be initiated in the operating room, and resuscitation must be effectively transitioned to the intensive care setting after the case. Good communication is vital to efficient patient movement along the continuum of care. The resuscitation that is undertaken before, during and after operative management must incorporate important changes in care of the trauma patient. This Clinical Practice Guideline hopes to provide a template for care of this patient population. It outlines a method of anesthesia that incorporates the induction and maintenance of anesthesia into an ongoing resuscitation during surgery for a trauma patient in extremis.

Hormone Therapy in Trauma Patients

Low-dose hydrocortisone reduces the dose of vasopressors and hospital length of stay; it may also decrease the rate of hospital-acquired pneumonia and time on ventilator. No major side effect was reported, but glycemia and natremia should be monitored. Progesterone did not enhance outcome of trauma patients. A meta-analysis suggested that oxandrolone was associated with shorter length of stay and reduced weight loss. Erythropoietin did not enhance neurologic outcome of traumatic brain-injured patients; such treatment, however, could reduce the mortality in subgroups of patients. This review focuses mainly on glucocorticoids, which are the most extensively investigated treatments in hormone therapy.

Guidelines for the diagnosis and management of critical illness-related corticosteroid insufficiency (CIRCI) in critically ill patients (Part I): Society of Critical Care Medicine (SCCM) and European Society of Intensive Care Medicine (ESICM) 2017

OBJECTIVE

To update the 2008 consensus statements for the diagnosis and management of critical illness-related corticosteroid insufficiency (CIRCI) in adult and pediatric patients.

PARTICIPANTS

A multispecialty task force of 16 international experts in Critical Care Medicine, endocrinology, and guideline methods, all of them members of the Society of Critical Care Medicine and/or the European Society of Intensive Care Medicine.

DESIGN/METHODS

The recommendations were based on the summarized evidence from the 2008 document in addition to more recent findings from an updated systematic review of relevant studies from 2008 to 2017 and were formulated using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology. The strength of each recommendation was classified as strong or conditional, and the quality of evidence was rated from high to very low based on factors including the individual study design, the risk of bias, the consistency of the results, and the directness and precision of the evidence. Recommendation approval required the agreement of at least 80% of the task force members.

RESULTS

The task force was unable to reach agreement on a single test that can reliably diagnose CIRCI, although delta cortisol (change in baseline cortisol at 60 min of <9 µg/dl) after cosyntropin (250 µg) administration and a random plasma cortisol of <10 µg/dl may be used by clinicians. We suggest against using plasma free cortisol or salivary cortisol level over plasma total cortisol (conditional, very low quality of evidence). For treatment of specific conditions, we suggest using intravenous (IV) hydrocortisone <400 mg/day for ≥3 days at full dose in patients with septic shock that is not responsive to fluid and moderate- to high-dose vasopressor therapy (conditional, low quality of evidence). We suggest not using corticosteroids in adult patients with sepsis without shock (conditional recommendation, moderate quality of evidence). We suggest the use of IV methylprednisolone 1 mg/kg/day in patients with early moderate to severe acute respiratory distress syndrome (PaO₂/FiO₂ < 200 and within 14 days of onset) (conditional, moderate quality of evidence). Corticosteroids are not suggested for patients with major trauma (conditional, low quality of evidence).

CONCLUSIONS

Evidence-based recommendations for the use of corticosteroids in critically ill patients with sepsis and septic shock, acute respiratory distress syndrome, and major trauma have been developed by a multispecialty task force.

A review of associated controversies surrounding glucocorticoid use in veterinary emergency and critical care

OBJECTIVE

To review the literature in human and veterinary medicine regarding the indications for, efficacy of, and controversies surrounding glucocorticoid (GC) administration in the emergency and critical care (ECC) setting, and to provide an overview of the most commonly used synthetic GC formulations.

MEDICATIONS

Synthetic GCs vary in GC and mineralocorticoid potency, hypothalamic pituitary axis suppression, duration of action, route of administration, and clinical indication for use. Some of the GC compounds commonly used in human and veterinary ECC include hydrocortisone, prednisone, methylprednisolone, and dexamethasone.

INDICATIONS FOR USE

GCs are used in human and veterinary ECC for a variety of disorders including anaphylaxis, acute lung injury/acute respiratory distress syndrome, septic shock, and spinal cord injury. Evidence for morbidity or mortality benefit with administration of GC within these populations exists; however, data are sparse and often conflicting.

ADVERSE EFFECTS AND CONTRAINDICATIONS

Routine use of GC in some conditions such as trauma, hemorrhagic shock, and traumatic brain injury is likely contraindicated. GC use has been associated with hyperglycemia, pneumonia, urinary tract infection, gastrointestinal ulceration, or increased mortality in some populations.

Effects of etomidate in the adrenal and cytokine responses to hemorrhagic shock in rats

Hemorrhagic shock (HS) induces a compensatory endocrine and cytokine response which aims to restore homeostasis. This response can be modulated by general anesthetics. To our knowledge, no studies have evaluated if etomidate modulates this response in experimental HS. After being premedicated with buprenorphine (0.05 mg/kg subcutaneously), male Wistar rats were anaesthetized with 5% isoflurane and divided into three groups: G1 (control, n = 16), G2 (n = 13), and G3 (n = 14). G2 and G3 were subjected to HS by collecting 30% of their blood volume and resuscitated 90 min later with the collected blood and normal saline, in a 1:3 ratio, respectively. G3 received etomidate (1 mg/kg IV) before HS. Blood gas analysis, adrenocorticotropic hormone (ACTH), corticosterone, and plasma levels of tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-10 and of TNF-α, IL-6, and IL-10 mRNA obtained through real-time polymerase chain reaction (RT-PCR) were measured at 0, 90, 150, and 240 min after HS induction. Compared with G2, etomidate-treated animals had significantly lower corticosterone, PO2, PO2/FiO2, base excess and HCO3, and higher TNF-α, IL-6, IL-10, and TNF-α mRNA levels ( P <0.05). Etomidate-treated rats showed impaired adrenal and increased cytokine response to HS and evidence of worse tissue oxygenation and lung dysfunction. Based on these results, and until further studies are performed to confirm if these findings occur in clinical patients, we suggest that etomidate should be used cautiously in HS.

Brain-lung crosstalk: Implications for neurocritical care patients

Major pulmonary disorders may occur after brain injuries as ventilator-associated pneumonia, acute respiratory distress syndrome or neurogenic pulmonary edema. They are key points for the management of brain-injured patients because respiratory failure and mechanical ventilation seem to be a risk factor for increased mortality, poor neurological outcome and longer intensive care unit or hospital length of stay. Brain and lung strongly interact via complex pathways from the brain to the lung but also from the lung to the brain. Several hypotheses have been proposed with a particular interest for the recently described “double hit” model. Ventilator setting in brain-injured patients with lung injuries has been poorly studied and intensivists are often fearful to use some parts of protective ventilation in patients with brain injury. This review aims to describe the epidemiology and pathophysiology of lung injuries in brain-injured patients, but also the impact of different modalities of mechanical ventilation on the brain in the context of acute brain injury.

Adrenal inhibition following a single dose of etomidate in intubated traumatic brain injury victims

Background:

Etomidate is frequently used to intubate traumatic brain injury (TBI) victims, even though it has been linked to adrenal insufficiency (AI) in some populations. Few studies have explored the risk of prolonged etomidateinduced AI among TBI victims.

Objective:

To determine the risk and the length of AI induced by etomidate in patients intubated for moderate and severe TBI.

Methods:

Participants in this observational study were moderate to severe intubated TBI victims aged ≥ 16 years. The anesthetic used (etomidate versus others) was determined solely by the treating emergency physician. Adrenocorticotropic hormone (ACTH) stimulation tests (250 µg) were performed 24, 48, and 168 hours after intubation. AI was defined as an increase in serumcortisol 1 hour post–ACTH test (delta cortisol) of less than 248.4 nmol/L.

Results:

Forty subjects (participation 42.6%) underwent ACTH testing. Fifteen received etomidate, and 25 received another anesthetic. There were no statistically significant differences between groups as to the cumulative incidence of AI at any measurement time. However, at 24 hours, exploratory post hoc analyses showed a significant decrease in delta cortisol (adjusted means: etomidate group: 305.1 nmol/L, 95% CI 214.7–384.8 versus other anesthetics: 500.5 nmol/L, 95% CI 441.8–565.7). This decrease was not present at 48 and 168 hours.

Conclusion:

In TBI victims, although a single dose of etomidate does not increase the cumulative incidence of AI as defined, it seems to decrease the adrenal response to an ACTH test for 24 hours. The clinical impacts of this finding remain to be determined.

Impact of Hemorrhagic Shock on Pituitary Function

BACKGROUND

Hypopituitarism after hypovolemic shock is well established in certain patient cohorts. However; the effects of hemorrhagic shock on pituitary function in trauma patients remains unknown. The aim of this study was to assess pituitary hormone variations in trauma patients with hemorrhagic shock.

STUDY DESIGN

Patients with acute traumatic hemorrhagic shock presenting to our level 1 trauma center were prospectively enrolled. Hemorrhagic shock was defined as systolic blood pressure (SBP) ≤ 90 mmHg on arrival or within 10 minutes of arrival in the emergency department, and requirement of ≥2 units of packed red blood cell transfusion. Serum cortisol and serum pituitary hormones (vasopressin [ADH], adrenocorticotrophic hormone [ACTH], thyroid stimulating hormone [TSH], follicular stimulating hormone [FSH], and luteinizing hormone [LH]) were measured in each patient on admission and at 24, 48, 72, and 96 hours after admission. Outcome measure was variation in pituitary hormones.

RESULTS

A total of 42 patients were prospectively enrolled; mean age was 37 ± 12 years, mean SBP 85.4 ± 64.5 mmHg, and median Injury Severity Score was 26 (range 18 to 38). There was an increase in the levels of cortisol (p < 0.001), a decrease in the levels of ACTH (p < 0.001) and ADH (p < 0.001), but no change in the levels of LH (p = 0.30), FSH (p = 0.07), and TSH (p = 0.89) over 96 hours. Ten patients died during their hospital stay. Patients who died had higher mean admission ADH levels (p = 0.03), higher mean admission ACTH levels (p < 0.001), and lower mean admission cortisol levels (p = 0.04) compared with patients who survived.

CONCLUSIONS

Acute hypopituitarism does not occur in trauma patients with acute hemorrhagic shock. In patients who died, there was a decrease in cortisol levels, which appears to be adrenal in origin.

Hydrocortisone prevents immunosuppression by interleukin-10+ natural killer cells after trauma-hemorrhage

OBJECTIVE

Trauma induces a state of immunosuppression, which is responsible for the development of nosocomial infections. Hydrocortisone reduces the rate of pneumonia in patients with trauma. Because alterations of dendritic cells and natural killer cells play a central role in trauma-induced immunosuppression, we investigated whether hydrocortisone modulates the dendritic cell/natural killer cell cross talk in the context of posttraumatic pneumonia.

DESIGN

Experimental study.

SETTINGS

Research laboratory from an university hospital.

SUBJECTS

Bagg Albino/cJ mice (weight, 20-24 g).

INTERVENTIONS

First, in an a priori substudy of a multicenter, randomized, double-blind, placebo-controlled trial of hydrocortisone (200 mg/d for 7 d) in patients with severe trauma, we have measured the blood levels of five cytokines (tumor necrosis factor-α, interleukin-6, interleukin-10, interleukin-12, interleukin-17) at day 1 and day 8. In a second step, the effects of hydrocortisone on dendritic cell/natural killer cell cross talk were studied in a mouse model of posttraumatic pneumonia. Hydrocortisone (0.6 mg/mice i.p.) was administered immediately after hemorrhage. Twenty-four hours later, the mice were challenged with Staphylococcus aureus (7 × 10 colony-forming units).

MEASUREMENTS AND MAIN RESULTS

Using sera collected during a multicenter study in patients with trauma, we found that hydrocortisone decreased the blood level of interleukin-10, a cytokine centrally involved in the regulation of dendritic cell/natural killer cell cluster. In a mouse model of trauma-hemorrhage-induced immunosuppression, splenic natural killer cells induced an interleukin-10-dependent elimination of splenic dendritic cell. Hydrocortisone treatment reduced this suppressive function of natural killer cells and increased survival of mice with posthemorrhage pneumonia. The reduction of the interleukin-10 level in natural killer cells by hydrocortisone was partially dependent on the up-regulation of glucocorticoid-induced tumor necrosis factor receptor-ligand (TNFsf18) on dendritic cell.

CONCLUSIONS

These data demonstrate that trauma-induced immunosuppression is characterized by an interleukin-10-dependent elimination of dendritic cell by natural killer cells and that hydrocortisone improves outcome by limiting this immunosuppressive feedback loop.

Critical illness-related corticosteroid insufficiency in cirrhotic patients with acute gastroesophageal variceal bleeding: risk factors and association with outcome*

OBJECTIVES

Critical illness-related corticosteroid insufficiency can adversely influence the prognosis of critically ill patients. However, its impact on the outcomes of patients with cirrhosis and acute gastroesophageal variceal bleeding remains unknown. We evaluated adrenal function using short corticotropin stimulation test in patients with cirrhosis and gastroesophageal variceal bleeding. The main outcomes analyzed were 5-day treatment failure and 6-week mortality.

DESIGN

Prospective observational study.

SETTING

Ten-bed gastroenterology-specific medical ICU at a 3,613-bed university teaching hospital in Taiwan.

PATIENTS

Patients with liver cirrhosis and acute gastroesophageal variceal bleeding.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We evaluated adrenal function using short corticotropin stimulation test in 157 episodes of gastroesophageal variceal bleeding in 143 patients with cirrhosis. Critical illness-related corticosteroid insufficiency occurred in 29.9% of patients. The patients with critical illness-related corticosteroid insufficiency had higher rates of treatment failure and 6-week mortality (63.8% vs 10.9%, 42.6% vs 6.4%, respectively; p < 0.001). The cumulative rates of survival at 6 weeks were 57.4% and 93.6% for the critical illness-related corticosteroid insufficiency group and normal adrenal function group, respectively (p < 0.001). The cortisol response to corticotropin was inversely correlated with Model for End-Stage Liver Disease and Child-Pugh scores and positively correlated with the levels of high-density lipoprotein and total cholesterol. Hypovolemic shock, high-density lipoprotein, platelet count, and bacterial infection at inclusion are independent factors predicting critical illness-related corticosteroid insufficiency, whereas critical illness-related corticosteroid insufficiency, Model for End-Stage Liver Disease score, hypovolemic shock, hepatocellular carcinoma, and active bleeding at endoscopy are independent factors to predict treatment failure. Multivariate analysis also identified Model for End-Stage Liver Disease score, hypovolemic shock, and bacterial infection at inclusion as independent factors associated with 6-week mortality.

CONCLUSIONS

Critical illness-related corticosteroid insufficiency is common in cirrhotic patients with acute gastroesophageal variceal bleeding and is an independent factor to predict 5-day treatment failure.

Systemic manifestations of traumatic brain injury

Traumatic brain injury (TBI) affects functioning of various organ systems in the absence of concomitant non-neurologic organ injury or systemic infection. The systemic manifestations of TBI can be mild or severe and can present in the acute phase or during the recovery phase. Non-neurologic organ dysfunction can manifest following mild TBI or severe TBI. The pathophysiology of systemic manifestations following TBI is multifactorial and involves an effect on the autonomic nervous system, involvement of the hypothalamic-pituitary axis, release of inflammatory mediators, and treatment modalities used for TBI. Endocrine dysfunction, electrolyte imbalance, and respiratory manifestations are common following TBI. The influence of TBI on systemic immune response, coagulation cascade, cardiovascular system, gastrointestinal system, and other systems is becoming more evident through animal studies and clinical trials. Systemic manifestations can independently act as risk factors for mortality and morbidity following TBI. Some conditions like neurogenic pulmonary edema and disseminated intravascular coagulation can adversely affect the outcome. Early recognition and treatment of systemic manifestations may improve the clinical outcome following TBI. Further studies are required especially in the field of neuroimmunology to establish the role of various biochemical cascades, not only in the pathophysiology of TBI but also in its systemic manifestations and outcome.

Use of propofol as an induction agent in the acutely injured patient

PURPOSE

Etomidate is a commonly used agent for rapid sequence induction (RSI) in trauma due to its limited hemodynamic effects. Given a recent nationwide shortage of etomidate, alternative induction agents may be required. Propofol is a frequent substitute; however, concern exists regarding its potential hypotensive effects. The study attempts to determine the hemodynamic effects of propofol and etomidate following RSI in trauma bay.

METHODS

A retrospective study was performed on 76 consecutive trauma patients requiring RSI at a single academic medical center. Patients were stratified by age, gender, mechanism of injury, Injury Severity Score (ISS), and Glasgow Coma Scale (GCS). Pre-induction and post-induction hemodynamic parameters were evaluated, and a multivariate regression analysis was performed.

RESULTS

The mean age was 42, ISS was 13, and GCS was 9.8. The mean dose of propofol was 127 ± 5 mg and the mean dose of etomidate was 21 ± 6 mg. Patients who received propofol were younger and had a lower ISS. The etomidate group had significantly increased post-induction systolic blood pressure but no difference in mean arterial pressure or heart rate when compared to pre-induction parameters. The propofol group had no significant changes in any post-induction parameter compared to pre-induction parameter.

CONCLUSION

RSI with propofol did not result in hypotension in our patient population, suggesting that a reduced dose of propofol may represent a reasonable alternative to etomidate in hemodynamically stable trauma patient. Further research is warranted to assess the safety of propofol in the acutely injured patient.

Increased Total Serum Random Cortisol Levels Predict Mortality in Critically Ill Trauma Patients

Dysfunction in the hypothalamopituitary adrenal axis is thought to exist; however, there continues to be controversy about what level of serum cortisol corresponds to adrenal insufficiency. Few studies have focused on the significance of serum random cortisol in the critically ill trauma patient. Trauma patients with total serum random cortisol levels drawn in the intensive care unit within the first seven days of hospitalization were retrospectively reviewed. The primary outcome measured was in-hospital mortality. Two hundred forty-two patients were analyzed. Non-survivors had significantly higher mean cortisol levels than survivors (28.7 ± 15.80 mg/dL vs 22.9 ± 12.35 mg/dL, P = 0.01). Patients with cortisol 30 mg/dL or greater were more likely to die with odds ratio of 2.7 (95% confidence interval [CI], 1.5 to 5). The odds ratio increased to 4.0 and 3.8 (95% CI, 1.4 to 11.4 and 1.3 to 10.9) when cortisol was drawn on hospital Day 2 and Days 3 through 7, respectively. Among nonsurvivors, patients with an injury severity score less than 25 had significantly higher cortisol levels than patients with an Injury Severity Score 25 or higher (35.3 ± 19.21 mg/dL vs 25.7 ± 13.21 mg/dL, P = 0.009). Patients with massive transfusion, traumatic brain injury, spinal cord injury, or solid organ injury did not have significantly different cortisol levels. The covariate-adjusted area under the receiver operating characteristic curve indicated that cortisol level has a 77 per cent accuracy in differentiating survivors from nonsurvivors. Higher cortisol levels were predictive of mortality in critically ill trauma patients. Whether serum cortisol level is a marker that can be modified remains an area of interest for future study.

Anesthetic induction with etomidate, rather than propofol, is associated with increased 30-day mortality and cardiovascular morbidity after noncardiac surgery

BACKGROUND

Because etomidate impairs adrenal function and blunts the cortisol release associated with surgical stimulus, we hypothesized that patients induced with etomidate suffer greater mortality and morbidity than comparable patients induced with propofol.

METHODS

We evaluated the electronic records of 31,148 ASA physical status III and IV patients who had noncardiac surgery at the Cleveland Clinic. Among these, anesthesia was induced with etomidate and maintained with volatile anesthetics in 2616 patients whereas 28,532 were given propofol for induction and maintained with volatile anesthetics. Two thousand one hundred forty-four patients given etomidate were propensity matched with 5233 patients given propofol and the groups compared on 30-day postoperative mortality, length of hospital stay, cardiovascular and infectious morbidities, vasopressor requirement, and intraoperative hemodynamics.

RESULTS

Patients given etomidate had 2.5 (98% confidence interval [CI], 1.9-3.4) times the odds of dying than those given propofol. Etomidate patients also had significantly greater odds of having cardiovascular morbidity (odds ratio [OR] [98% CI]: 1.5 [1.2-2.0]), and significantly longer hospital stay (hazard ratio [95% CI]: 0.82 [0.78-0.87]). However, infectious morbidity (OR [98% CI]: 1.0 [0.8-1.2]) and intraoperative vasopressor use (OR [95% CI] 0.92: [0.82-1.0]) did not differ between the agents.

CONCLUSION

Etomidate was associated with a substantially increased risk for 30-day mortality, cardiovascular morbidity, and prolonged hospital stay. Our conclusions, especially on 30-day mortality, are robust to a strong unmeasured binary confounding variable. Although our study showed only an association between etomidate use and worse patients' outcomes but not causal relationship, clinicians should use etomidate judiciously, considering that improved hemodynamic stability at induction may be accompanied by substantially worse longer-term outcomes.

Characterizing vasopressin and other vasoactive mediators released during resuscitation of trauma patients

BACKGROUND

We sought to perform the first characterization of vasopressin and other vasoactive mediators released during resuscitation of hypotensive trauma patients.

METHODS

This institutional review board-approved study was conducted under waiver of consent. Adults with clinical evidence of acute traumatic injury and systolic blood pressure less than or equal to 90 mm Hg within 1 hour of arrival were evaluated at our Level I trauma center. Two hundred three patients were screened with 50 enrolled from February 2010 to February 2011. Demographic information was also collected. Blood samples were obtained at 0, 30, 60, 90, 120, and 240 minutes after arrival, and assays were performed for vasopressin, angiotensin II, epinephrine, and cortisol. We assessed the significance of variation in these vasoactive mediators with injury and transfusion of more than 600 mL, with adjustment for time using repeated-measures linear models in log units.

RESULTS

We found that vasopressin (p = 0.005) and epinephrine (p = 0.01) increased significantly with injury, while angiotensin (p = 0.60) and cortisol (p = 0.46) did not and that vasopressin (p < 0.001) and epinephrine (p = 0.004) increased significantly in patients requiring transfusion of more than 600 mL but angiotensin II (p = 0.11) and cortisol (p = 0.90) did not. Relatively low levels of vasopressin (<30 pg/mL) were observed at least once during the first 2 hours in 88% of trauma patients, and abnormally low epinephrine levels (<100 pg/mL) were observed at least once during the first 2 hours in 18% of trauma patients.

CONCLUSION

This is the first clinical trial to serially evaluate vasopressin and other vasoactive mediators following trauma during the resuscitation phase. Vasopressin, in particular, and epinephrine seem to be the key mediators produced in the human response to severe injury. A deficiency of vasopressin may contribute to intractable shock after trauma.

LEVEL OF EVIDENCE

Prognostic/epidemiologic study, level III.

A new way of thinking: hydrocortisone in traumatic brain-injured patients

Data suggest that treatment of critical illness-related corticosteroid insufficiency after traumatic brain injury (TBI) with a stress dose of hydrocortisone may improve the neurological outcome and the mortality rate. The mineralocorticoid properties of hydrocortisone may reduce the rate of hyponatremia and of brain swelling. The exaggerated inflammatory response may cause critical illness-related corticosteroid insufficiency by altering the function of the hypothalamic–pituitary–adrenal axis, and hydrocortisone is able to restore a balanced inflammatory response rather than inducing immunosuppression. Hydrocortisone could also prevent neuronal apoptosis. Considering side effects, corticosteroids are not equal; when a high dose of synthetic corticosteroids seems detrimental, a strategy using a stress dose of hydrocortisone seems attractive. Finally, results from a large multicenter study are needed to close the debate regarding the use of hydrocortisone in TBI patients.

Operative care and surveillance in severe trauma patients. Interference between resuscitation treatments and anaesthesiology, and consequence on immunity

Major trauma remains a worldwide cause of morbi-mortality. Early mortality is the consequence of hemorrhagic shock and traumatic brain injury. During early resuscitation, anaesthesia is often mandatory to perform surgery. It is mandatory to master the hemodynamic effects of hypnotic drugs in order to anticipate their potential deleterious effects in the setting of hemorrhagic shock. After early resuscitation, trauma patients present a high prevalence of nosocomial pneumonia, which sustains major morbidity. Nosocomial pneumonia are the consequence of an overwhelming systemic inflammatory response syndrome (SIRS) as well as a trauma-related immunosuppression. The administration of hemisuccinate of hydrocortisone modulates the SIRS and reduces the risk of nosocomial pneumonia as well as the length of mechanical ventilation. Finally in the operating theatre, fighting against hypothermia and un-anatomical positions, which can aggravate rhabdomyolysis, are both mandatory.

Etomidate increases susceptibility to pneumonia in trauma patients

PURPOSE

To investigate the impact of etomidate on the rate of hospital-acquired pneumonia (HAP) in trauma patients and the effects of hydrocortisone in etomidate-treated patients.

METHODS

This was a sub-study of the HYPOLYTE multi-centre, randomized, double-blind, placebo-controlled trial of hydrocortisone in trauma patients (NCT00563303). Inclusion criterion was trauma patient with mechanical ventilation (MV) of ≥48 h. The use of etomidate was prospectively collected. Endpoints were the results of the cosyntropin test and rate of HAP on day 28 of follow-up.

RESULTS

Of the 149 patients enrolled in the study, 95 (64 %) received etomidate within 36 h prior to inclusion. 79 (83 %) of 95 patients receiving etomidate and 34 of the 54 (63 %) not receiving etomidate had corticosteroid insufficiency (p = 0.006). The administration of etomidate did not alter basal cortisolemia (p = 0.73), but it did decrease the delta of cortisolemia at 60 min (p = 0.007). There was a correlation between time from etomidate injection to inclusion in the study and sensitivity to corticotropin (R (2) = 0.19; p = 0.001). Forty-nine (51.6 %) patients with etomidate and 16 (29.6 %) patients without etomidate developed HAP by day 28 (p = 0.009). Etomidate was associated with HAP on day 28 in the multivariate analysis (hazard ratio 2.48; 95 % confidence interval 1.19-5.18; p = 0.016). Duration of MV with or without etomidate was not significantly different (p = 0.278). Among etomidate-exposed patients, 18 (40 %) treated with hydrocortisone developed HAP compared with 31 (62 %) treated with placebo (p = 0.032). Etomidate-exposed patients treated with hydrocortisone had fewer ventilator days (p < 0.001).

CONCLUSIONS

Among the patients enrolled in the study, etomidate did not alter basal cortisolemia, but it did decrease reactivity to corticotropin. We suggest that in trauma patients, etomidate is an independent risk factor for HAP and that the administration of hydrocortisone should be considered after etomidate use.

Review article: update in trauma anesthesiology: perioperative resuscitation management

The management of trauma patients has matured significantly since a systematic approach to trauma care was introduced nearly a half century ago. The resuscitation continuum emphasizes the effect that initial therapy has on the outcome of the trauma patient. The initiation of this continuum begins with prompt field medical care and efficient transportation to designated trauma centers, where lifesaving procedures are immediately undertaken. Resuscitation with packed red blood cells and plasma, in parallel with surgical or interventional radiologic source control of bleeding, are the cornerstones of trauma management. Adjunctive pharmacologic therapy can assist with resuscitation. Tranexamic acid is used in Europe with good results, but the drug is slowly being added to the pharmacy formulary of trauma centers in United States. Recombinant factor VIIa can correct abnormal coagulation values, but its outcome benefit is less clear. Vasopressin shows promise in animal studies and case reports, but has not been subjected to a large clinical trial. The concept of "early goal-directed therapy" used in sepsis may be applicable in trauma as well. An early, appropriately aggressive resuscitation with blood products, as well as adjunctive pharmacologic therapy, may attenuate the systemic inflammatory response of trauma. Future investigations will need to determine whether this approach offers a similar survival benefit.

Endogenous glucocorticoids promote the expansion of myeloid-derived suppressor cells in a murine model of trauma

Stress-dose of glucocorticoid has been demonstrated to be beneficial for trauma patients in clinical studies. Recently, a heterogeneous population of myeloid cells with immunosuppressive activity named myeloid-derived suppressor cells (MDSCs) has been found to accumulate in the trauma host and can be induced by glucocorticoids in vitro. In order to explore the effect of endogenous glucocorticoids on MDSCs under trauma conditions, we blocked the glucocorticoid signal in a murine trauma model using the antagonist of the glucocorticoid receptor RU486 (mifepristone). We found for the first time that RU486 not only blunted MDSC expansion induced by trauma in the spleen, peripheral blood and bone marrow especially at 6 h after traumatic stress but also decreased the survival rate from 100 to 20% in traumatic mice within 7 days. Moreover, neither MDSCs producing arginase-1 nor the morphological characterization of trauma-induced MDSCs was affected by the blockage of the glucocorticoid receptor. Our results suggest that endogenous glucocorticoids may promote MDSCs expansion in a murine trauma model and MDSCs may be beneficial for the trauma host.

Pathophysiology of hypopituitarism in the setting of brain injury

The complex pathophysiology of traumatic brain injury (TBI) involves not only the primary mechanical event but also secondary insults such as hypotension, hypoxia, raised intracranial pressure and changes in cerebral blood flow and metabolism. It is increasingly evident that these initial insults as well as transient events and treatments during the early injury phase can impact hypothalamic-pituitary function both acutely and chronically after injury. In turn, untreated pituitary hormonal dysfunction itself can further hinder recovery from brain injury. Secondary adrenal insufficiency, although typically reversible, occurs in up to 50% of intubated TBI victims and is associated with lower systemic blood pressure. Chronic anterior hypopituitarism, although reversible in some patients, persists in 25-40% of moderate and severe TBI survivors and likely contributes to long-term neurobehavioral and quality of life impairment. While the rates and risk factors of acute and chronic pituitary dysfunction have been documented for moderate and severe TBI victims in numerous recent studies, the pathophysiology remains ill-defined. Herein we discuss the hypotheses and available data concerning hypothalamic-pituitary vulnerability in the setting of head injury. Four possible pathophysiological mechanisms are considered: (1) the primary brain injury event, (2) secondary brain insults, (3) the stress of critical illness and (4) medication effects. Although each of these factors appears to be important in determining which hormonal axes are affected, the severity of dysfunction, their time course and possible reversibility, this process remains incompletely understood.

Corticotherapy for traumatic brain-injured patients--the Corti-TC trial: study protocol for a randomized controlled trial

Background

Traumatic brain injury (TBI) is a main cause of severe prolonged disability of young patients. Hospital acquired pneumonia (HAP) add to the morbidity and mortality of traumatic brain-injured patients. In one study, hydrocortisone for treatment of traumatic-induced corticosteroid insufficiency (CI) in multiple injured patients has prevented HAP, particularly in the sub-group of patients with severe TBI. Fludrocortisone is recommended in severe brain-injured patients suffering from acute subarachnoid hemorrhage. Whether an association of hydrocortisone with fludrocortisone protects from HAP and improves neurological recovery is uncertain. The aim of the current study is to compare corticotherapy to placebo for TBI patients with CI.

Methods

The CORTI-TC (Corticotherapy in traumatic brain-injured patients) trial is a multicenter, randomized, placebo controlled, double-blind, two-arms study. Three hundred and seventy six patients hospitalized in Intensive Care Unit with a severe traumatic brain injury (Glasgow Coma Scale ≤ 8) are randomized in the first 24 hours following trauma to hydrocortisone (200 mg.day^-1 for 7 days, 100 mg on days 8-9 and 50 mg on day-10) with fludrocortisone (50 μg for 10 days) or double placebo. The treatment is stopped if patients have an appropriate adrenal response. The primary endpoint is HAP on day-28. The endpoint of the ancillary study is the neurological status on 6 and 12 months.

Discussion

The CORTI-TC trial is the first randomized controlled trial powered to investigate whether hydrocortisone with fludrocortisone in TBI patients with CI prevent HAP and improve long term recovery.

Trial registration

NCT01093261

Incidence and Outcomes of Critical Illness-Related Corticosteroid Insufficiency in Trauma Patients

The spectrum of critical illness-related corticosteroid insufficiency (CIRCI) in trauma is not fully defined. This study describes our trauma experience with hydrocortisone-treated patients experiencing CIRCI. We conducted a 5-year retrospective analysis from a Level II trauma center using biochemical and clinical criteria for adrenal insufficiency. Seventy patients met the inclusion criteria for CIRCI. There was a 34 per cent mortality rate despite therapy. Nonsurvivors were older with larger admission base deficits and experienced higher rates of sepsis, bacteremia, and pneumonia. Nonsurvivors had prolonged vent days (mean 53 ± 64 days) when compared with survivors (mean 30 ± 22 days; P = 0.029). Renal replacement therapy was a strong predictor of mortality. Spinal cord-injured patients had high Injury Severity Scores (mean 34 ± 18), elevated baseline Cortisol levels (mean 56 ± 84 vs 18 ± 14; P = 0.004), and required prolonged duration of steroid therapy (30 ± 52 vs 15 ± 15 days; P = 0.080) when compared with the nonspinal cord-injured group. Our data suggest that CIRCI in trauma is associated with significant mortality and morbidity even when patients are treated appropriately.

Corticosteroids for severe sepsis: an evidence-based guide for physicians

Septic shock is characterized by uncontrolled systemic inflammation that contributes to the progression of organ failures and eventually death. There is now ample evidence that the inability of the host to mount an appropriate hypothalamic-pituitary and adrenal axis response plays a major in overwhelming systemic inflammation during infections. Proinflammatory mediators released in the inflamed sites oppose to the anti-inflammatory response, an effect that may be reversed by exogenous corticosteroids. With sepsis, via nongenomic and genomic effects, corticosteroids restore cardiovascular homeostasis, terminate systemic and tissue inflammation, restore organ function, and prevent death. These effects of corticosteroids have been consistently found in animal studies and in most recent frequentist and Bayesian meta-analyses. Corticosteroids should be initiated only in patients with sepsis who require 0.5 μg/kg per minute or more of norepinephrine and should be continued for 5 to 7 days except in patients with poor hemodynamic response after 2 days of corticosteroids and with a cortisol increment of more than 250 nmol/L after a standard adrenocorticotropin hormone (ACTH) test. Hydrocortisone should be given at a daily dose of 200 mg and preferably combined to enteral fludrocortisone at a dose of 50 μg. Blood glucose levels should be kept below 150 mg/dL.

Increased creatinine clearance in polytrauma patients with normal serum creatinine: a retrospective observational study

INTRODUCTION

The aim of this study, performed in an intensive care unit (ICU) population with a normal serum creatinine, was to estimate urinary creatinine clearance (CLCR) in a population of polytrauma patients (PT) through a comparison with a population of non trauma patients (NPT).

METHODS

This was a retrospective, observational study in a medical and surgical ICU in a university hospital. A total of 284 patients were consecutively included. Two different groups were studied: PT (n = 144) and NPT (n = 140). Within the second week after admission to the ICU, renal function was assessed using serum creatinine, 24 h urinary CLCR .

RESULTS

Among the 106 patients with a CLCR above 120 mL minute(-1) 1.73 m(-2), 79 were PT and 27 NPT (P < 0.0001). Only 63 patients had a CLCR below 60 mL minute(-1) 1.73 m(-2) with 15 PT and 48 NPT (P < 0.0001). Patients with CLCR greater than 120 mL minute(-1). 1.73 m(-2) were younger, had a lower SAPS II score and a higher male ratio as compared to those having CLCR lower than 120 mL minute(-1). 1.73 m(-2). Through a logistic regression analysis, age and trauma were the only factors independently correlated to CLCR.

CONCLUSIONS

In ICU patients with normal serum creatinine, CLCR, is higher in PT than in NPT. The measure of CLCR should be proposed as routine for PT patients in order to adjust dose regimen, especially for drugs with renal elimination.

Correlation between brain interstitial and total serum cortisol levels in traumatic brain injury. A preliminary study

INTRODUCTION

Brain cortisol availability has never been evaluated in patients with traumatic brain injury (TBI). Cerebral microdialysis is a well-established technique for monitoring brain metabolism in neurocritically ill patients, which may be used to measure interstitial cortisol. The objective of this preliminary study was to measure brain interstitial cortisol and its correlation with total serum cortisol in patients with TBI.

METHODS

We prospectively studied 6 patients with severe TBI admitted to the Intensive Care Unit of our tertiary University Hospital in which multimodal neuromonitoring including cerebral microdialysis with a high cut-off of 100 k-Da and 20-mm long membrane was used. Serum and brain interstitial cortisol microdialysis samples were obtained every 8 h and analyzed afterwards.

RESULTS

Linear regression analysis of total serum cortisol and brain interstitial cortisol in the whole population showed a moderate correlation (R2=0.538, p<0.001, no.=118). However, intra-individual correlation showed a great variability, with correlation coefficients ranging from a R2=0.091 to R2=0.680.

CONCLUSION

Our prospective and preliminary study showed a moderate correlation of brain interstitial cortisol and total serum cortisol values in patients with diffuse TBI. However, intra-individual analysis showed a great variability. These results suggest that total serum cortisol may not reflect brain cortisol availability in half of TBI patients.

A prospective study on the incidence and predictive factors of relative adrenal insufficiency in Korean critically-ill patients

This study was undertaken to evaluate the incidence and risk factors associated with relative adrenal insufficiency (RAI) in Korean critically-ill patients. All patients who were admitted to the Medical Intensive Care Unit (MICU) of Samsung Medical Center between January 1, 2006 and April 30, 2007 were prospectively evaluated using a short corticotropin stimulation test on the day of admission. RAI was defined as an increase in the serum cortisol level of <9 microg/dL from the baseline after administration of 250 microg of corticotropin. In all, 123 patients were recruited and overall the incidence of RAI was 44% (54/123). The presence of septic shock (P=0.001), the Simplified Acute Physiology Score (SAPS) II (P=0.003), the Sequential Organ Failure Assessment (SOFA) score (P=0.001), the mean heart rate (P=0.040), lactate levels (P=0.001), arterial pH (P=0.047), treatment with vasopressors at ICU admission (P=0.004), and the 28-day mortality (P=0.041) were significantly different between patients with and without RAI. The multivariate analysis showed that the SOFA score was an independent predictor of RAI in critically-ill patients (odd ratio=1.235, P=0.032). Our data suggest that RAI is frequently found in Korean critically-ill patients and that a high SOFA score is an independent predictor of RAI in these patients.

Acute Adrenal Insufficiency May Affect Outcome in the Trauma Patient

Acute adrenal insufficiency in the trauma patient is underrecognized and the impact poorly understood. Our hypothesis was that the identification and treatment of acute adrenal insufficiency reduces mortality in trauma patients. Institutional Review Board approval for the retrospective review of a prospective database from a Level 1 trauma center for 2002 to 2004 was obtained. The study population included patients receiving a cosyntropin stimulation test (250 μg) and/or random Cortisol level based on our practice management guideline and an intensive care unit stay longer than 24 hours. Demographic, acuity, and outcome data were collected. The nonresponders had baseline Cortisol levels less than 20 μg/dL or poststimulation rise less than 9 μg/dL. Independent t tests and χ2 statistics were used. One hundred thirty-seven patients had cosyntropin stimulation tests performed. Eighty-two (60%) patients were nonresponders of which 66 were treated with hydrocortisone and 16 went untreated as a result of the discretion of the attending physician. The 55 (40%) responders showed no statistical differences in outcome variables whether or not they received hydrocortisone. The untreated adrenal-insufficient patients had significantly higher mortality, longer hospital length of stay, intensive care unit days, and ventilator-free days. Conclusions were: 1) treatment of acute adrenal insufficiency reduces mortality by almost 50 per cent in the trauma patient; and 2) acute adrenal insufficiency recognized by low random Cortisol levels or nonresponse to a stimulation tests should be considered for treatment.

[Should etomidate still be used?]

Etomidate blocks the cortisol synthesis by specifically inhibiting the activity of 11 beta-hydroxylase, resulting in a primary adrenal insufficiency. Therefore, a serum accumulation of 11 beta-deoxycortisol and a low secretion of serum cortisol must be required as diagnostic criteria to assign that adrenal impairment to the drug. These requirements have been rarely fulfilled in studies exploring the contribution of etomidate to the adrenal insufficiency despite numerous causes of adrenal derangement. In critically ill patients without sepsis, a single dose of etomidate results in a wide adrenal inhibition, reversible in 48 h after etomidate administration. Although there are still uncertainties as to whether etomidate directly affects mortality and morbidity, it seems preferable to avoid the use of etomidate in patients with severe sepsis and septic shock. In patients with severe traumatic brain injury, arterial hypotension is one of major factors of poor outcome and can be prevented with the use of etomidate for facilitating tracheal intubation. Substitutive opotherapy with low doses of hydrocortisone should be assessed after a single dose of etomidate for critically ill patients.

Medication-related complications in the trauma patient

Trauma patients are twice as likely to have adverse reactions to medication as nontrauma patients. The need for medication in trauma patients is high. Surgery is often necessary, and immunosuppression and hypercoagulability may be present. Adverse drug events can be caused in part by altered pharmacokinetics, drug interactions, and polypharmacy. Medications may also have serious long-term adverse effects, which must be considered. It is not the purpose of this review article to discuss all adverse effects of all medications. This article will discuss the more common adverse effects of medications for trauma patients in the acute care setting, in the following categories: pain control, sedation, antibiotics, seizure prophylaxis in head trauma, atrial fibrillation, deep vein thrombosis and pulmonary embolism prophylaxis, hemodynamic support, adrenal insufficiency, factor VIIa.

Predicting a low cortisol response to adrenocorticotrophic hormone in the critically ill: a retrospective cohort study

Introduction

Identification of risk factors for diminished cortisol response to adrenocorticotrophic hormone (ACTH) in the critically ill could facilitate recognition of relative adrenal insufficiency in these patients. Therefore, we studied predictors of a low cortisol response to ACTH.

Methods

A retrospective cohort study was conducted in a general intensive care unit of a university hospital over a three year period. The study included 405 critically ill patients, who underwent a 250 μg ACTH stimulation test because of prolonged hypotension or need for vasopressor/inotropic therapy. Plasma cortisol was measured before and 30 and 60 min after ACTH injection. A low adrenal response was defined as an increase in cortisol of less than 250 nmol/l or a peak cortisol level below 500 nmol/l. Various clinical variables were collected at admission and on the test day.

Results

A low ACTH response occurred in 63% of patients. Predictors, in multivariate analysis, included sepsis at admission, low platelets, low pH and bicarbonate, low albumin levels, high Sequential Organ Failure Assessment score and absence of prior cardiac surgery, and these predictors were independent of baseline cortisol and intubation with etomidate. Baseline cortisol/albumin ratios, as an index of free cortisol, were directly related and increases in cortisol/albumin were inversely related to disease severity indicators such as the Simplified Acute Physiology Score II and Sequential Organ Failure Assessment score (Spearman r = -0.21; P < 0.0001).

Conclusion

In critically ill patients, low pH/bicarbonate and platelet count, greater severity of disease and organ failure are predictors of a low adrenocortical response to ACTH, independent of baseline cortisol values and cortisol binding capacity in blood. These findings may help to delineate relative adrenal insufficiency and suggest that adrenocortical suppression occurs as a result of metabolic acidosis and coagulation disturbances.

Adrenal insufficiency in critical illness

One of the more controversial areas in critical care in recent decades relates to the issue of adrenal insufficiency and its treatment in critically ill patients. There is no consensus on which patients to test for adrenal insufficiency, which tests to use and how to interpret them, whether to use corticosteroids, and, if so, who to treat and with what dose. This review illustrates the complexity and diversity of pathophysiological changes in glucocorticoid secretion, metabolism, and action and how these are affected by various types of illness. It will review adrenal function testing and give guidance on corticosteroid replacement regimens based on current published literature. There remain inherent difficulties in interpreting the effects of glucocorticoid replacement during critical illness because of the diversity of effects of glucocorticoids on various tissues. Investigation and treatment will depend on whether the likely cause of corticosteroid insufficiency is adrenal or central in origin.

Adrenal function in different subgroups of septic shock patients

BACKGROUND

Relative adrenal insufficiency (RAI) is a common complication during septic shock and may be more frequent in specific subgroups. The main objectives of this study were to determine the adrenal function and the RAI incidence in different subgroups of septic shock patients considering: main admission categories (medical, elective or emergency surgery); source of infection; nosocomial or community-acquired infections; gender, age <65 years or >65 years; and the presence or absence of neurological diseases, acute respiratory distress syndrome (ARDS) and bacteremia.

METHODS

Prospective study in a medical-surgical ICU, including adults with septic shock, from May 2002 to May 2005. All patients had total serum cortisol measured at baseline and 60 min after a high-dose ACTH test within the first 96 h of shock onset. RAI was defined as a serum cortisol increment after ACTH test (Deltamax(249)) <90 microg/l.

RESULTS

One hundred and two subjects were enrolled, and the overall RAI incidence was 22.5%. Patients with ARDS before ACTH test or bacteremia showed lower Deltamax(249) values than patients with ARDS after ACTH test (96 vs. 153 microg/l, P=0.02) or without bacteremia (140 vs. 175 microg/l, P=0.04). Multivariate regression analysis revealed that female gender, development of ARDS before ACTH test, and bacteremia were associated with greater RAI incidence. There was no difference in RAI incidence considering neurological diseases, age, type and source of infection and the main admission categories.

CONCLUSIONS

Female gender, bacteremia and early-onset ARDS were variables independently associated with greater RAI incidence in septic shock patients. There was no difference in the RAI incidence concerning other subgroups.

Duration of adrenal inhibition following a single dose of etomidate in critically ill patients

OBJECTIVE

To determine the incidence and duration of adrenal inhibition induced by a single dose of etomidate in critically ill patients.

DESIGN

Prospective, observational cohort study.

SETTING

Three intensive care units in a university hospital.

PATIENTS

Forty critically ill patients without sepsis who received a single dose of etomidate for facilitating endotracheal intubation.

MEASUREMENTS AND MAIN RESULTS

Serial serum cortisol and 11beta-deoxycortisol samples were taken at baseline and 60 min after corticotropin stimulation test (250 microg 1-24 ACTH) at 12, 24, 48, and 72 h after etomidate administration. Etomidate-related adrenal inhibition was defined by the combination of a rise in cortisol less than 250 nmol/l (9 microg/dl) after ACTH stimulation and an excessive accumulation of serum 11beta-deoxycortisol concentrations at baseline. At 12 h after etomidate administration, 32/40 (80%) patients fulfilled the diagnosis criteria for etomidate-related adrenal insufficiency. This incidence was significantly lower at 48 h (9%) and 72 h (7%). The cortisol to 11beta-deoxycortisol ratio (F/S ratio), reflecting the intensity of the 11beta-hydroxylase enzyme blockade, improved significantly over time.

CONCLUSIONS

A single bolus infusion of etomidate resulted in wide adrenal inhibition in critically ill patients. However, this alteration was reversible by 48 h following the drug administration. The empirical use of steroid supplementation for 48 h following a single dose of etomidate in ICU patients without septic shock should thus be considered. Concomitant serum cortisol and 11beta-deoxycortisol dosages are needed to provide evidence for adrenal insufficiency induced by etomidate in critically ill patients.

Relationship between plasma adrenocorticotropin hormone and intensive care unit survival in early traumatic brain injury

BACKGROUND

Hypothalamic pituitary adrenal response has been recently evaluated in patients with traumatic brain injury (TBI) with different results. Our objective was to study this response and its relationship with outcome in the early stage after TBI.

METHODS

We conducted a prospective observational clinical study in the intensive care unit of a tertiary level university hospital. The study included 50 consecutive patients who suffered isolated TBI. Intracranial pressure (ICP) was measured by an intraparenchymal probe. All patients were sedated and mechanically ventilated. Second-level measures were provided as per protocol, when needed. We measured plasma adrenocorticotropin hormone (ACTH) levels, as well as baseline and stimulated serum cortisol after a high-dose corticotrophin stimulation test, within 2 days after TBI for all patients.

RESULTS

Mean age was 36 +/- 18 (range 16-77) years. Forty-four (88%) were male. Median Glasgow Coma Scale score was 7. Mean ACTH was 15.4 +/- 19.8 pg/mL. Mean baseline cortisol was 14.8 +/- 9.0 microg/dL and mean stimulated cortisol was 27.1 +/- 7.3 microg/dL and 30.5 +/- 7.2 microg/dL at 30 and 60 minutes, respectively. Baseline and stimulated cortisol were not correlated with mortality. Logistic regression analysis revealed that, either plasma ACTH levels <9 pg/mL or lack of indication to provide second-level measures to control ICP were significant independent predictors of survival.

CONCLUSIONS

The presence of a low plasma ACTH concentration at an early stage of TBI and lack of indication to provide second-level measures to control ICP were associated with a higher intensive care unit survival.

Basal serum cortisol levels are not predictive of response to corticotropin but have prognostic significance in patients with septic shock

Because high levels of cortisol are frequently observed in patients with septic shock, low levels of serum cortisol are considered indicative of relative adrenal insufficiency (RAI). This study was performed to investigate whether pretest clinical characteristics, including basal serum cortisol levels, are predictive of serum cortisol response to corticotropin and whether basal cortisol levels have a prognostic significance in patients with septic shock. We performed a retrospective analysis of 68 patients with septic shock who underwent short corticotropin stimulation testing. RAI was defined as an increase in cortisol level <9 microgram/dL from baseline, and results showed that 48 patients (70.6%) had this insufficiency. According to the univariate analysis, the RAI group had significantly higher simplified acute physiology score II (SAPS II) and sequential organ failure assessment (SOFA) scores than the non-RAI group. The incidence of RAI was the same regardless of the basal serum cortisol level (p=0.447). The hospital mortality rate was 58.8% and was not significantly different between the RAI and non-RAI groups. However, a high basal serum cortisol level (> or =30 microgram/dL) was significantly associated with in-hospital mortality. In conclusion, our data suggest that basal serum cortisol levels are not predictive of serum cortisol response to corticotropin but have a significant prognostic value in patients with septic shock.

Corticosteroid replacement in critically ill patients

This review addresses the use of corticosteroid replacement in critically ill patients. Low-dose corticosteroid replacement for critically ill patients with septic shock has been shown to reduce the duration of vasopressor-dependent shock, to shorten ICU length of stay, and, in recent trials, to reduce mortality. Numerous questions remain to be fully answered about patient selection, corticotropin-stimulation testing methods, and interpretation of results.