Irini Mavrou

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.

Prognostic importance of increased plasma amino-terminal pro-brain natriuretic peptide levels in a large noncardiac, general intensive care unit population.

The present study aimed to determine whether amino-terminal pro-brain natriuretic peptide (NT-pro-BNP) predicts intensive care unit (ICU) mortality in a cohort of general, noncardiac, critically ill patients. To this end, a total of 233 consecutive mechanically ventilated patients (109 men) having a median age of 60 years and a wide range in admitting diagnoses, including medical (n = 118), surgical (n = 83), and multiple trauma (n = 32) cases were prospectively studied. Median Acute Physiology and Chronic Health Evaluation (APACHE) II and Sequential Organ Failure Assessment scores on ICU admission were 16 and 9, respectively. The study end point was ICU outcome. Blood samples were drawn on admission in the ICU and on postadmission days 1 and 2 to determine NT-pro-BNP levels. In a subgroup (n = 77), admission proinflammatory and anti-inflammatory cytokine levels, including TNF-&agr;, IL-6, and IL-10, were also measured. Nonsurvivors (n = 98) had significantly higher NT-pro-BNP levels than survivors (n = 135) on admission in the ICU (2,074 vs. 283 pg/mL; P < 0.001), on day 1 (2,197 vs. 221 pg/mL; P < 0.001), and on day 2 (2,726 vs. 139 pg/mL; P < 0.001). Median values for TNF-&agr;, IL-6, and IL-10 were 3.70, 131.57, and 111.88 pg/mL, respectively. Receiver operating characteristic analysis showed that the area under the receiver operating characteristic curve in predicting ICU mortality was 0.70 for APACHE II and 0.77 for admission NT-pro-BNP (P = 0.08). The cutoff in admission NT-pro-BNP that best predicted outcome was 941 pg/mL. Multiple logistic regression analysis revealed that APACHE II score (odds ratio, 1.06; P = 0.007) and the best cutoff point in admission NT-pro-BNP (odds ratio, 7.74; P < 0.001) independently predicted ICU mortality, even if cytokines were entered in the analysis. In conclusion, plasma NT-pro-BNP is frequently raised in noncardiac, mixed, critically ill patients, and nonsurvivors have consistently higher levels than survivors. Elevated admission NT-pro-BNP represents an independent predictor for poor ICU outcome in the presence of clinical severity scores.

Venous Oxygen Saturation And Lactate Gradient From Superior Vena Cava To Pulmonary Artery In Patients With Septic Shock

Monitoring of central venous oxygen saturation (ScvO2) is considered comparable with mixed venous oxygen saturation (SvO2) in the initial resuscitation phase of septic shock. Our aim was to assess their agreement in septic shock in the intensive care unit setting and the effect of a potential difference in a computed parameter, namely, oxygen consumption (VO2). In addition, we sought for a central venous to pulmonary artery (PA) lactate gradient. We enrolled 37 patients with septic shock who were receiving noradrenaline infusions, and their attending physicians had placed a PA catheter for fluid management. Blood samples were drawn in succession from the superior vena cava, right atrium (RA), right ventricle, and PA. Hemodynamic and treatment parameters were monitored, and data were compared by correlation and Bland-Altman analysis. Mixed venous oxygen saturation was lower than ScvO2 (70.2% ± 11.4% vs. 78.6% ± 10.2%; P < 0.001), with a bias of −8.45% and 95% limits of agreement ranging from −20.23% to 3.33%. This difference correlated significantly to the noradrenaline infusion rate and the oxygen consumption and extraction ratio. These lower SvO2 values resulted in computed VO2v higher than the VO2cv (P < 0.001), with a bias of 104.97 mL min−1 and 95% limits of agreement from −4.12 to 214.07 mL min−1. Finally, lactate concentration was higher in the superior vena cava and RA than in the PA (2.42 ± 3.15 and 2.35 ± 3.16 vs. 2.17 ± 3.19 mM; P < 0.01 for both comparisons). Thus, our data suggest that ScvO2 and SvO2 are not equivalent in intensive care unit patients with septic shock. Additionally, the substitution of ScvO2 for SvO2 in the calculation of VO2 produces unacceptably large errors. Finally, the decrease in lactate between RA and PA may support the hypothesis that the mixing of RA and coronary sinus blood is at least partially responsible for the difference between ScvO2 and SvO2.

Association of left ventricular diastolic dysfunction with elevated NT-pro-BNP in general intensive care unit patients with preserved ejection fraction: a complementary role of tissue Doppler imaging parameters and NT-pro-BNP levels for adverse outcome.

The mechanisms of the N-terminal-pro-brain natriuretic peptide (NT-pro-BNP) release in intensive care unit (ICU) patients with preserved ejection fraction (EF) are unclear. We investigated whether left ventricular (LV) dysfunction, as assessed by tissue Doppler imaging (TDI), is related to NT-pro-BNP levels in ICU patients with preserved EF and has a complementary value to NT-pro-BNP in the determination of in-hospital mortality. We examined 58 mechanically ventilated patients with no history of heart failure (age, 60 ± 18 years; EF, 63% ± 7%). The systolic (S) and early diastolic (E&vprime;) velocity of the mitral annulus by TDI and the E/E&vprime; as well as NT-pro-BNP, troponin, lactate acid, blood oxygen (PO2/FiO2), sepsis, and ICU mortality were assessed. Systolic, E&vprime;, and E/E&vprime; correlated with age, PO2/FiO2, lactate acid, NT-pro-BNP, troponin, history of arterial hypertension, and diabetes (P < 0.05). By multivariate analysis, the determinants of NT-pro-BNP were S (P = 0.024), E/E&vprime; (P = 0.017), and sepsis (P = 0.015). An NT-pro-BNP greater than 941 pg/mL was a reliable predictor of LV diastolic dysfunction defined as a composite of E&vprime; less than or equal to 8 cm/s and/or mean E/E greater than or equal to 13 (area under the curve, 75%; P = 0.03). Patients with combined NT-pro-BNP greater than 941 pg/mL and abnormal TDI markers had increased creatinine levels and a lower MAP, PO2/FiO2, and survival rate than those with abnormal TDI or NT-pro-BNP alone or patients with normal TDI markers and NT-pro-BNP (25%, 60%, 70%, and 84%, respectively; P < 0.05). The addition of abnormal TDI in a model including NT-pro-BNP and sepsis increased the models value for in-hospital mortality (P for change = 0.01). In ICU patients with preserved EF, LV diastolic dysfunction and sepsis determine NT-pro-BNP levels. Tissue Doppler imaging markers and NT-pro-BNP have a complementary value for in-hospital mortality.

Early serum levels of soluble triggering receptor expressed on myeloid cells–1 in septic patients: Correlation with monocyte gene expression☆

PURPOSE To define early kinetics of soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) and of TREM-1 monocyte gene expression in critically ill patients with sepsis. METHODS Blood was sampled at regular time intervals from 105 patients with sepsis. Concentrations of tumour necrosis factor α (TNFα), interleukin (IL)-6, IL-8 and IL-10 and IL-12p70 and sTREM-1 were measured by an enzyme immunoassay. Blood mononuclear cells were isolated on day 0 from 20 patients and 10 healthy volunteers; RNA was extracted and gene expression of TREM-1 and TNFα were assessed by reverse transcriptase polymerase chain reaction. RESULTS Early serum concentrations of sTREM-1 were greater among patients with severe sepsis/shock than among patients with sepsis; those of TNFα, IL-6, IL-8 and IL-10 were pronounced among patients with septic shock. Gene transcripts of TNFα were lower among patients with severe sepsis/shock than among patients with sepsis; that was not the case for TREM-1. Early serum levels of sTREM-1 greater than 180 pg/mL were predictors of shorter duration of mechanical ventilation. CONCLUSIONS Although serum levels of sTREM-1 are increased early upon advent of severe sepsis/shock, gene expression of TREM-1 on monocytes in severe sepsis/shock is not increased. These findings add considerably to our knowledge on the pathophysiology of sepsis.

Thyroid Function Changes and Cytokine Alterations following Major Surgery

To establish whether cytokine release is implicated in thyroid hormone changes during surgical stress we studied 36 adult patients (20 men; mean age ± SD: 68.5 ± 10.5 years) undergoing elective major abdominal operations. We measured tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-8 and IL-10 and thyrotropin (TSH), free thyroxine (FT4) and triiodothyronine (T3) before scheduled non-emergency surgery, immediately postoperatively, on the 1st postoperative day (post-1) and on the 2nd postoperative day (post-2). TNF-α, IL-6 and IL-8 peaked on day post-1 whereas IL-10 peaked immediately postoperatively. Fourteen of 36 patients had low T3 levels after surgery, indicating non-thyroidal illness (NTI). Significant negative correlations were noted among TNF-α, IL-6 and IL-8 against T3 and FT4. Cytokines are responsible, at least in part, for NTI following major operations.

Reduction of Environmental Contamination With Multidrug-Resistant Bacteria by Copper-Alloy Coating of Surfaces in a Highly Endemic Setting

OBJECTIVE To evaluate the efficacy of copper-coating in reducing environmental colonization in an intensive-care unit (ICU) with multidrug-resistant-organism (MDRO) endemicity DESIGN Interventional, comparative crossover trial SETTING The general ICU of Attikon University hospital in Athens, Greece PATIENTS Those admitted to ICU compartments A and B during the study period METHODS Before any intervention (phase 1), the optimum sampling method using 2 nylon swabs was validated. In phase 2, 6 copper-coated beds (ie, with coated upper, lower, and side rails) and accessories (ie, coated side table, intravenous [i.v.] pole stands, side-cart handles, and manual antiseptic dispenser cover) were introduced as follows: During phase 2a (September 2011 to February 2012), coated items were placed next to noncoated ones (controls) in both compartments A and B; during phase 2b (May 2012 to January 2013), all copper-coated items were placed in compartment A, and all noncoated ones (controls) in compartment B. Patients were randomly assigned to available beds. Environmental samples were cultured quantitatively for clinically important bacteria. Clinical and demographic data were collected from medical records. RESULTS Copper coating significantly reduced the percentage of colonized surfaces (55.6% vs 72.5%; P<.0001), the percentage of surfaces colonized by MDR gram-negative bacteria (13.8% vs 22.7%; P=.003) or by enterococci (4% vs 17%; P=.014), the total bioburden (2,858 vs 7,631 cfu/100 cm2; P=.008), and the bioburden of gram-negative isolates, specifically (261 vs 1,266 cfu/100 cm2; P=.049). This effect was more pronounced when the ratio of coated surfaces around the patient was increased (phase 2b). CONCLUSIONS Copper-coated items in an ICU setting with endemic high antimicrobial resistance reduced environmental colonization by MDROs. Infect Control Hosp Epidemiol 2017;38:765-771.

Angiopoietin-2 Levels as Predictors of Outcome in Mechanically Ventilated Patients with Acute Respiratory Distress Syndrome

Pulmonary endothelium dysfunction is a key characteristic of ARDS. The aim of this study was to investigate endothelium-derived markers, such as angiopoietin-2 (Ang-2) and endothelial cell-specific molecule-1 (endocan), at the vascular and alveolar compartments as outcome predictors in ARDS. Fifty-three consecutive ARDS patients were studied. The primary outcome was 28-day mortality. Secondary endpoints were days of unassisted ventilation and days with organ failure other than ARDS, during the 28-day study period. Nonsurvivors presented higher lung injury scores and epithelial lining fluid (ELF) Ang-2 levels compared to survivors, with no significant differences in plasma Ang-2, endocan, and protein C concentrations between the two groups. In logistic regression analysis, ELF Ang-2 levels > 705 pg/ml were the only independent variable for 28-day mortality among the previous four. Plasma endocan values > 13 ng/pg were the only parameter predictive against days of unassisted ventilation during the 28-day study period. Finally, lung injury score > 2.25 and ELF Ang-2 levels > 705 pg/ml were associated with increased number of days with organ failure, other than ARDS. Our findings suggest that Ang-2 levels are increased in the alveolar compartment of ARDS patients, and this may be associated both with increased mortality and organ failure besides lung.

Prognostic value of plasma amino-terminal pro-brain natriuretic peptide in a large, representative ICU population

We sought to determine whether amino-terminal pro-brain natriuretic peptide (NT-proBNP) predicts ICU outcome in a representative cohort of mechanically ventilated, critically ill patients.