Ioanna Dimopoulou

Recommendations for the diagnosis and management of corticosteroid insufficiency in critically ill adult patients: Consensus statements from an international task force by the American College of Critical Care Medicine

Objective:To develop consensus statements for the diagnosis and management of corticosteroid insufficiency in critically ill adult patients. Participants:A multidisciplinary, multispecialty task force of experts in critical care medicine was convened from the membership of the Society of Critical Care Medicine and the European Society of Intensive Care Medicine. In addition, international experts in endocrinology were invited to participate. Design/Methods:The task force members reviewed published literature and provided expert opinion from which the consensus was derived. The consensus statements were developed using a modified Delphi methodology. The strength of each recommendation was quantified using the Modified GRADE system, which classifies recommendations as strong (grade 1) or weak (grade 2) and the quality of evidence as high (grade A), moderate (grade B), or low (grade C) based on factors that include the study design, the consistency of the results, and the directness of the evidence. Results:The task force coined the term critical illness–related corticosteroid insufficiency to describe the dysfunction of the hypothalamic-pituitary-adrenal axis that occurs during critical illness. Critical illness–related corticosteroid insufficiency is caused by adrenal insufficiency together with tissue corticosteroid resistance and is characterized by an exaggerated and protracted proinflammatory response. Critical illness–related corticosteroid insufficiency should be suspected in hypotensive patients who have responded poorly to fluids and vasopressor agents, particularly in the setting of sepsis. At this time, the diagnosis of tissue corticosteroid resistance remains problematic. Adrenal insufficiency in critically ill patients is best made by a delta total serum cortisol of <9 &mgr;g/dL after adrenocorticotrophic hormone (250 &mgr;g) administration or a random total cortisol of <10 &mgr;g/dL. The benefit of treatment with glucocorticoids at this time seems to be limited to patients with vasopressor-dependent septic shock and patients with early severe acute respiratory distress syndrome (Pao2/Fio2 of <200 and within 14 days of onset). The adrenocorticotrophic hormone stimulation test should not be used to identify those patients with septic shock or acute respiratory distress syndrome who should receive glucocorticoids. Hydrocortisone in a dose of 200 mg/day in four divided doses or as a continuous infusion in a dose of 240 mg/day (10 mg/hr) for ≥7 days is recommended for septic shock. Methylprednisolone in a dose of 1 mg·kg−1·day−1 for ≥14 days is recommended in patients with severe early acute respiratory distress syndrome. Glucocorticoids should be weaned and not stopped abruptly. Reinstitution of treatment should be considered with recurrence of signs of sepsis, hypotension, or worsening oxygenation. Dexamethasone is not recommended to treat critical illness–related corticosteroid insufficiency. The role of glucocorticoids in the management of patients with community-acquired pneumonia, liver failure, pancreatitis, those undergoing cardiac surgery, and other groups of critically ill patients requires further investigation. Conclusion:Evidence-linked consensus statements with regard to the diagnosis and management of corticosteroid deficiency in critically ill patients have been developed by a multidisciplinary, multispecialty task force.

Angiopoietin-2 is increased in severe sepsis: correlation with inflammatory mediators.

Objective: Angiopoietin (Ang)‐2 is an endothelium‐specific growth factor, regulated by proinflammatory stimuli, that destabilizes vascular endothelium and increases vascular leakage; consequently, Ang‐2 may contribute to sepsis pathophysiology. We have studied 1) serum Ang‐2 levels in critically‐ill patients and investigated potential relationships with inflammatory mediators and indices of disease severity and 2) the effect of sepsis‐related inflammatory mediators on Ang‐2 production by lung endothelium in vitro. Design: Prospective clinical study followed by cell culture studies. Setting: General intensive care unit and research laboratory of a university hospital. Subjects: Human and bovine lung microvascular endothelial cells and 61 patients (32 men). Patients were grouped according to their septic stage as having: no systemic inflammatory response syndrome (n = 6), systemic inflammatory response syndrome (n = 8), sepsis (n = 16), severe sepsis (n = 18), and septic shock (n = 13). Interventions: Cells were exposed to lipopolysaccharide, tumor necrosis factor‐&agr;, and interleukin‐6. Measurements and Main Results: Patients’ serum Ang‐2 levels were significantly increased in severe sepsis as compared with patients with no systemic inflammatory response syndrome or sepsis (p < .05 by analysis of variance). Positive linear relationships were observed with: serum tumor necrosis factor‐&agr; (rs = 0.654, p < .001), serum interleukin‐6 (rs = 0.464, p < .001), Acute Physiology and Chronic Health Evaluation II score (rs = 0.387, p < .001), and Sequential Organ Failure Assessment score (rs = 0.428, p < .001). Multiple regression analysis revealed that serum Ang‐2 is mostly related to serum tumor necrosis factor‐&agr; and severe sepsis. Treatment of human lung microvascular endothelial cells with all mediators resulted in a concentration‐dependent Ang‐2 reduction. Treatment of bovine lung microvascular endothelial cells with lipopolysaccharide and tumor necrosis factor‐&agr; increased Ang‐2 release, and interleukin‐6 reduced basal Ang‐2 levels. Conclusions: First, patients’ serum Ang‐2 levels are increased during severe sepsis and associated with disease severity. The strong relationship of serum Ang‐2 with serum tumor necrosis factor‐&agr; suggests that the latter may participate in the regulation of Ang‐2 production in sepsis. Second, inflammatory mediators reduce Ang‐2 release from human lung microvascular endothelial cells, implying that this vascular bed may not be the source of increased Ang‐2 in human sepsis.

Hypothalamic-pituitary-adrenal axis dysfunction in critically ill patients with traumatic brain injury: incidence, pathophysiology, and relationship to vasopressor dependence and peripheral interleukin-6 levels.

ObjectiveTo investigate hypothalamic-pituitary-adrenal axis function in patients requiring mechanical ventilation for traumatic brain injury and to assess the relation of hypothalamic-pituitary-adrenal axis abnormalities with vasopressor dependence and peripheral cytokine levels. DesignProspective study. SettingGeneral intensive care unit in a university teaching hospital. PatientsForty patients (33 men and 7 women) with moderate to severe traumatic brain injury (mean age, 37 ± 16 yrs) were studied the day after termination of mechanical ventilation (7–60 days after trauma). InterventionsFirst, a morning blood sample was obtained to measure baseline cortisol, corticotropin, interleukin-6, and tumor necrosis factor alpha. Subsequently, 1 &mgr;g of synthetic corticotropin was injected intravenously, and 30 mins later, a second blood sample was drawn to determine stimulated plasma cortisol. Based on data derived from healthy volunteers, patients having stimulated cortisol levels <18 &mgr;g/dL were defined as nonresponders to the low-dose stimulation test. Thirty-one patients underwent also a human corticotropin releasing hormone test. Measurements and Main ResultsIn traumatic brain injury patients, mean baseline and low-dose stimulation test-stimulated cortisol levels were 17.2 ± 5.4 &mgr;g/dL and 24.0 ± 6.6 &mgr;g/dL, respectively. The median increment in cortisol was 5.9 &mgr;g/dL. Basal corticotropin levels ranged from 3.9 to 118.5 pg/mL. Six of the 40 patients (15%) failed the low-dose stimulation test. The human corticotropin releasing hormone test (performed in 26 responders and five nonresponders) revealed diminished cortisol release only in the low-dose stimulation test nonresponder patients. Corticotropin responses to corticotropin releasing hormone were consistent with both primary (three patients) and/or secondary (two patients) adrenal dysfunction. In retrospect, nonresponders to the low-dose stimulation test more frequently required vasopressors (6/6 [100%] vs. 16/34 [47%]; p = .02) and for a longer time interval (median, 0 vs. 293 hrs; p = .006) compared with responders. Furthermore, nonresponders had higher interleukin-6 levels compared with responders (56.03 vs. 28.04 pg/mL; p = .01), whereas tumor necrosis factor alpha concentrations were similar in the two groups (2.42 vs. 1.55 pg/mL; p = .53). ConclusionsAdrenal cortisol secretion after dynamic stimulation is deficient in a subset of critically ill patients with moderate to severe head injury. This disorder is associated with prior vasopressor dependency and higher interleukin-6 levels.

Early alterations of the innate and adaptive immune statuses in sepsis according to the type of underlying infection

IntroductionAlthough major changes of the immune system have been described in sepsis, it has never been studied whether these may differ in relation to the type of underlying infection or not. This was studied for the first time.MethodsThe statuses of the innate and adaptive immune systems were prospectively compared in 505 patients. Whole blood was sampled within less than 24 hours of advent of sepsis; white blood cells were stained with monoclonal antibodies and analyzed though a flow cytometer.ResultsExpression of HLA-DR was significantly decreased among patients with severe sepsis/shock due to acute pyelonephritis and intraabdominal infections compared with sepsis. The rate of apoptosis of natural killer (NK) cells differed significantly among patients with severe sepsis/shock due to ventilator-associated pneumonia (VAP) and hospital-acquired pneumonia (HAP) compared with sepsis. The rate of apoptosis of NKT cells differed significantly among patients with severe sepsis/shock due to acute pyelonephritis, primary bacteremia and VAP/HAP compared with sepsis. Regarding adaptive immunity, absolute counts of CD4-lymphocytes were significantly decreased among patients with severe sepsis/shock due to community-acquired pneumonia (CAP) and intraabdominal infections compared with sepsis. Absolute counts of B-lymphocytes were significantly decreased among patients with severe sepsis/shock due to CAP compared with sepsis.ConclusionsMajor differences of the early statuses of the innate and adaptive immune systems exist between sepsis and severe sepsis/shock in relation to the underlying type of infection. These results may have a major impact on therapeutics.

Impact of catheter-related bloodstream infections on the mortality of critically ill patients: a meta-analysis.

Objective: There is controversy on whether catheter-related bloodstream infections (CR-BSI) affect the mortality of critically ill patients. Design: Meta-analysis of comparative studies that reported on mortality of intensive care unit (ICU) adult patients with and without CR-BSI. Methods: PubMed, Current Contents, and reference lists of retrieved publications were searched with no language or time restrictions. Heterogeneity was assessed by means of I2-statistic and chi-square test. Publication bias was detected by the funnel plot method using Egger’s test. Pooled odds ratios (OR) and 95% confidence intervals (CI) were calculated by implementing both the Mantel–Haenszel fixed effect and the DerSimonian–Laird random effects model. Results: Eight studies, involving 2,540 ICU patients, were included. Heterogeneity was detected (I2 = 0.67, 95% CI 0.32–0.85, p = 0.003). Publication bias was not found (Egger’s test, p = 0.28). All-cause in-hospital mortality was higher in ICU patients with CR-BSI than in those without CR-BSI (fixed effect model: OR = 1.81, 95% CI 1.44–2.28; random effects model: OR = 1.96, 95% CI 1.25–3.09). This was also the case for the subgroup analysis of the studies that were matched for severity of illness (fixed effect model: OR = 1.65, 95% CI 1.28–2.13; random effects model: OR = 1.70, 95% CI 1.00–2.90). Conclusion: Presence, as opposed to absence, of CR-BSI is associated with higher mortality in critically ill adult patients. This finding seems to justify and may enhance efforts to prevent CR-BSI in such patients.

High incidence of neuroendocrine dysfunction in long-term survivors of aneurysmal subarachnoid hemorrhage.

Background and Purpose— To investigate the incidence, pattern, and magnitude of neuroendocrine changes in long-term survivors of aneurysmal subarachnoid hemorrhage (SAH). Methods— Thirty patients (16 women) with a mean age of 50±13 years underwent endocrine assessment between 12 and 24 months after aneurysmal SAH. SAH severity was graded clinically by the Hunt & Hess scale (median, II) and radiologically by the Fisher classification (median, II). Patients underwent measurement of basal hormone levels and dynamic assessment by the low-dose (1 &mgr;g) corticotropin stimulation test. Functional outcome was examined concurrently with endocrine testing by the modified Rankin Scale and the Barthel Index. Results— Of the 30 patients tested, 14 patients (47%) showed isolated or combined endocrine abnormalities. These included low insulin-like growth factor 1 levels compatible with growth hormone deficiency in 37%, hypogonadism in 13%, and cortisol hyporesponsiveness to the low-dose corticotropin stimulation test in 10%; thyroid dysfunction in the form of subclinical hypothyroidism was observed in 7% of patients. Median modified Rankin Scale and Barthel Index at the time of endocrine testing were 1 and 100, respectively. There was no correlation between the presence of endocrine dysfunction and SAH severity indices or functional outcome scores. Conclusions— Long-term survivors of aneurysmal SAH frequently exhibit endocrine changes, with growth hormone and gonadal deficiencies predominating. Thus, screening of pituitary function is recommended in patients surviving SAH. The relationship between late hormonal alterations and functional outcome in patients with SAH warrants further study.

Association between activation of the renin-angiotensin system and secondary erythrocytosis in patients with chronic obstructive pulmonary disease

PURPOSE An association between activation of the renin-angiotensin system and enhanced erythropoiesis has been observed in patients with several diseases, including congestive heart failure and hypertension. Our goal was to examine whether the renin-angiotensin system is associated with secondary erythrocytosis in patients with chronic obstructive pulmonary disease (COPD). SUBJECTS AND METHODS Plasma renin activity, plasma aldosterone concentration, serum erythropoietin level, and serum angiotensin converting enzyme (ACE) activity were measured in 12 patients with COPD and secondary erythrocytosis [mean (+/-SD) hematocrit of 53% +/- 3%] and in 12 matched controls with COPD who did not have erythrocytosis (hematocrit 45% +/- 5%). All patients had chronic hypoxemia (PaO2 <60 mm Hg). RESULTS Both plasma renin and aldosterone levels were threefold greater in patients with secondary erythrocytosis compared to controls. No difference in erythropoietin levels was observed between patients with or without secondary erythrocytosis. Renin levels (r = 0.45; P = 0.02) but not erythropoietin levels (r = 0.15; P = 0.47) were correlated with hematocrit in the entire sample. Renin levels and PaO2 were the only variables independently and significantly associated with hematocrit values in a multiple linear regression model. CONCLUSION Activation of the renin-angiotensin system is associated with the development of secondary erythrocytosis in chronically hypoxemic patients with COPD. The exact mechanism is not yet fully understood, but angiotensin II may be responsible for inappropriately sustained erythropoietin secretion or direct stimulation of erythroid progenitors.

Health-related quality of life and disability in survivors of multiple trauma one year after intensive care unit discharge.

Dimopoulou I, Anthi A, Mastora Z, Theodorakopoulou M, Konstandinidis A, Evangelou E, Mandragos K, Roussos C: Health-related quality of life and disability in survivors of multiple trauma one year after intensive care unit discharge. Am J Phys Med Rehabil 2004;83:171–176. ObjectiveTo evaluate health-related quality of life and disability in multiple-trauma patients requiring intensive care unit management. DesignA total of 87 survivors of multiple trauma, with a median age of 31 yrs and a median Injury Severity Score of 22, were enrolled in the present study. The Nottingham Health Profile, Glasgow Outcome Scale, and Rosser Disability Scale were used to assess the functional consequences of trauma 1 yr after intensive care unit discharge. ResultsA total of 64 of 87 patients had a problem in at least one of the six domains related to subjective health status. The most prevalent complaint was related to somatic subdimensions, but emotional functioning was also affected. Nottingham Health Profile part 2 showed that 63 of the survivors experienced problems in at least one of the daily activities. Of particular importance, inability to work was reported by 47% of the patients. Fifty-nine percent experienced moderate-to-severe disability as evaluated by Glasgow Outcome Scale and Rosser Disability Scale. High aggregate injury severity score along with severe head trauma were independent predictors of poor health-related quality of life and disability. ConclusionsThe majority of survivors of major trauma exhibit considerable levels of disability and impairment in health-related quality of life. Global injury severity score and degree of brain trauma determine functional limitations. This information may help in organizing long-term rehabilitation of multiple-trauma patients.

High prevalence of decreased cortisol reserve in brain-dead potential organ donors.

ObjectiveTo investigate the adrenocortical function in brain-dead patients, potential organ donors. DesignProspective study. SettingIntensive care units in two teaching hospitals. PatientsA total of 37 patients (28 men, nine women) with severe brain injury, having a mean age of 42 ± 18 yrs, were included in the study. Group A consisted of 20 brain-injured patients who did not deteriorate to brain death. Group B included 17 brain-injured patients who were brain dead; of these, ten patients developed brain death during ICU stay and seven patients were admitted to the ICU after clinical brain death. InterventionsIn all patients (group A and group B), a morning blood sample was obtained at admission to the ICU to determine baseline plasma cortisol. Subsequently, 1 &mgr;g of corticotropin (adrenocorticotropic hormone, Synacthen) was administered intravenously, and a blood sample was taken 30 mins after the injection. In group B patients who became brain dead while being treated in the ICU (n = 10), the same procedure was repeated the morning after the confirmation of brain death. Patients having a cortisol level of at least 18 &mgr;g/dL after the administration of adrenocorticotropic hormone were defined as responders. Measurements and Main ResultsAfter the occurrence of brain death, group B patients had significantly lower values for baseline (8.5 ± 6.2 vs. 17.0 ± 6.6 &mgr;g/dL, p < .001) and stimulated (16.9 ± 6.3 vs. 23.9 ± 5.7 &mgr;g/dL, p = .001) plasma cortisol compared with group A patients. Thirteen group B patients (76%) and two group A patients (10%) were nonresponders to adrenocorticotropic hormone (p < .001). In group B patients, baseline and stimulated cortisol concentrations were significantly related (r = .71, p = .001), whereas there was no correlation between baseline cortisol and the increment in cortisol (r = −.37, p = .15). Mean hormonal data of the ten brain-dead patients studied at admission in the ICU and after the occurrence of brain death were the following: baseline plasma cortisol (23.5 ± 11.4 vs. 6.8 ± 4.2 &mgr;g/dL, p = .003) and stimulated serum cortisol (28.8 ± 9.9 vs. 16.3 ± 4.3 &mgr;g/dL, p = .008). ConclusionsAdrenal cortisol secretion after dynamic stimulation is deficient in a substantial proportion of brain-dead potential organ donors.

Protein S-100b serum levels in trauma-induced brain death

Objective: To analyze the time course of serum protein S-100b in patients with traumatic brain injury deteriorating to brain death and to investigate the predictive value of initial S-100b levels in relation to clinical and radiologic measures of injury severity with regard to brain death. Methods: Forty-seven patients who sustained severe head injury were studied. Blood samples for measurement of S-100b were drawn on admission in the intensive care unit and every 24 hours thereafter for a maximum of 6 consecutive days or until brain death occurred. Variables related to outcome were recorded, including age, sex, Glasgow Coma Scale (GCS), and brain CT findings on admission. Outcome was defined as deterioration to brain death or not. Results: Of the 47 patients studied, 17 deteriorated to brain death and 30 did not. On admission, patients who became brain dead had higher median serum S-100b levels compared with those who did not (2.32 μg/L vs 1.04 μg/L, p = 0.0028). Logistic regression analysis showed that initial S-100b was an independent predictor of brain death (p = 0.041), in the presence of advanced age (p = 0.043) and low GCS score (p = 0.013). The odds ratio of 2.09 (95% CI, 1.03 to 4.25) indicates a more than doubling of the probability of deteriorating to brain death per 1-μg/L increase in S-100b on admission. At clinical brain death, median S-100b was higher in patients with brain death compared with the peak S-100b value obtained over a 6-day period in those who did not become brain dead (6.58 μg/L vs 1.49 μg/L, p < 0.0001). Conclusions: Prediction of brain death after severe head injury can be improved by combining clinical and S-100b data; thus, serum S-100b determination deserves to be included in the neuromonitoring of patients with severe traumatic brain injury.