Serum procalcitonin for the early recognition of nosocomial infection in the critically ill patients: a preliminary report

<p>Abstract</p> <p>Background</p> <p>The usefulness of procalcitonin (PCT) measurement in critically ill medical patients with suspected nosocomial infection is unclear. The aim of the study was to assess PCT value for the early diagnosis of bacterial nosocomial infection in selected critically ill patients.</p> <p>Methods</p> <p>An observational cohort study in a 15-bed intensive care unit was performed. Seventy patients with either proven (n = 47) or clinically suspected but not confirmed (n = 23) nosocomial infection were included. Procalcitonin measurements were obtained the day when the infection was suspected (D0) and at least one time within the 3 previous days (D-3 to D0). Patients with proven infection were compared to those without. The diagnostic value of PCT on D0 was determined through the construction of the corresponding receiver operating characteristic (ROC) curve. In addition, the predictive value of PCT variations preceding the clinical suspicion of infection was assessed.</p> <p>Results</p> <p>PCT on D0 was the best predictor of proven infection in this population of ICU patients with a clinical suspicion of infection (AUROCC = 0.80; 95% CI, 0.68–0.91). Thus, a cut-off value of 0.44 ng/mL provides sensitivity and specificity of 65.2% and 83.0%, respectively. Procalcitonin variation between D-1 and D0 was calculated in 45 patients and was also found to be predictive of nosocomial infection (AUROCC = 0.89; 95% CI, 0.79–0.98) with a 100% positive predictive value if the +0.26 ng/mL threshold value was applied. Comparable results were obtained when PCT variation between D-2 and D0, or D-3 and D0 were considered. In contrast, CRP elevation, leukocyte count and fever had a poor predictive value in our population.</p> <p>Conclusion</p> <p>PCT monitoring could be helpful in the early diagnosis of nosocomial infection in the ICU. Both absolute values and variations should be considered and evaluated in further studies.</p

Serum procalcitonin elevation in critically ill patients at the onset of bacteremia caused by either gram negative or gram positive bacteria

<p>Abstract</p> <p>Background</p> <p>In the ICU, bacteremia is a life-threatening infection whose prognosis is highly dependent on early recognition and treatment with appropriate antibiotics. Procalcitonin levels have been shown to distinguish between bacteremia and noninfectious inflammatory states accurately and quickly in critically ill patients. However, we still do not know to what extent the magnitude of PCT elevation at the onset of bacteremia varies according to the Gram stain result.</p> <p>Methods</p> <p>Review of the medical records of every patient treated between May, 2004 and December, 2006 who had bacteremia caused by either Gram positive (GP) or Gram negative (GN) bacteria, and whose PCT dosage at the onset of infection was available.</p> <p>Results</p> <p>97 episodes of either GN bacteremia (<it>n </it>= 52) or GP bacteremia (<it>n </it>= 45) were included. Procalcitonin levels were found to be markedly higher in patients with GN bacteremia than in those with GP bacteremia, whereas the SOFA score value in the two groups was similar. Moreover, in the study population, a high PCT value was found to be independently associated with GN bacteremia. A PCT level of 16.0 ng/mL yielded an 83.0% positive predictive value and a 74.0% negative predictive value for GN-related bacteremia in the study cohort (AUROCC = 0.79; 95% CI, 0.71–0.88).</p> <p>Conclusion</p> <p>In a critically ill patient with clinical sepsis, GN bacteremia could be associated with higher PCT values than those found in GP bacteremia, regardless of the severity of the disease.</p

Impact of previous sepsis on the accuracy of procalcitonin for the early diagnosis of blood stream infection in critically ill patients

<p>Abstract</p> <p>Background</p> <p>Blood stream infections (BSI) are life-threatening infections in intensive care units (ICU), and prognosis is highly dependent on early detection. Procalcitonin levels have been shown to accurately and quickly distinguish between BSI and noninfectious inflammatory states in critically ill patients. It is, however, unknown to what extent a recent history of sepsis (namely, secondary sepsis) can affect diagnosis of BSI using PCT.</p> <p>Methods</p> <p>review of the medical records of every patient with BSI in whom PCT dosage at the onset of sepsis was available between 1^stSeptember, 2006 and 31^stJuly, 2007.</p> <p>Results</p> <p>179 episodes of either primary (<it>n </it>= 117) or secondary (<it>n </it>= 62) sepsis were included. Procalcitonin levels were found to be markedly lower in patients with secondary sepsis than in those without (6.4 [9.5] vs. 55.6 [99.0] ng/mL, respectively; <it>p </it>< 0.001), whereas the SOFA score was similar in the two groups. Although patients in the former group were more likely to have received steroids and effective antibiotic therapy prior to the BSI episode, and despite a higher proportion of candidemia in this group, a low PCT value was found to be independently associated with secondary sepsis (Odd Ratio = 0.33, 95% Confidence Interval: 0.16–0.70; <it>p </it>= 0.004). Additional patients with suspected but unconfirmed sepsis were used as controls (<it>n </it>= 23). Thus, diagnostic accuracy of PCT as assessed by the area under the receiver-operating characteristic curves (AUROCC) measurement was decreased in the patients with secondary sepsis compared to those without (AUROCC = 0.805, 95% CI: 0.699–0.879, vs. 0.934, 95% CI: 0.881–0.970, respectively; <it>p </it>< 0.050).</p> <p>Conclusion</p> <p>In a critically ill patient with BSI, PCT elevation and diagnosis accuracy could be lower if sepsis is secondary than in those with a first episode of infection.</p

Is There a Correlation between Vitamin C Status and Catecholamines Concentrations in Hemodialysis Patients?

International audienceIt is well established that there is a high incidence of cardiovascular diseases in hemodialysis patients, and involvement of oxidative stress has been hypothesised in these phenomena. Plasma norepinephrine is an independent predictor of many causes of mortality in general, and high norepinephrine levels predict cardiovascular complications in end stage renal disease. the aim of our study was to evaluate the potential link between vitamin c status, a marker of oxidative stress, and catecholamine concentrations before and after hemodialysis sessions. In a prospective study of 16 chronic hemodialysis patients, ascorbyl free radical levels were directly measured using electron spin resonance spectroscopy. these values were expressed with respect to vitamin c concentrations to obtain a direct index of oxidative stress. Vitamin c, epinephrine and norepinephrine were measured by high performance liquid chromatography. the data were examined for correlations between these compounds and clinical parameters including blood pressure and heart rates. In hemodialysis patients, ascorbyl free radical/vitamin C ratios increased significantly after dialysis. No differences were observed for catecholamine concentrations during hemodialysis sessions. In multivariate analysis, the ascorbyl free radical/vitamin c ratio did not correlate with epinephrine or norepinephrine levels. In our study, plasma norepinephrine and ascorbyl free radical/vitamin c ratios were not related among patients with end-stage renal disease. From these findings, we conclude that although these two factors are likely to be involved in the same causal pathway leading to cardiovascular events, it is likely that they seem to be independent

Mechanisms and etiologies of thrombocytopenia in the intensive care unit: impact of extensive investigations

International audienceAbstractBackground:Thrombocytopenia is common in the intensive care unit. Potential mechanisms and etiologiesbehind this phenomenon are multiple and often entangled. We assessed the effect of a systematic approach, usingroutinely available tests, on the proportion of patients in whom the mechanism (primary objective) and etiology(secondary objective) of thrombocytopenia in a mixed intensive care unit (ICU) could be identified.Methods:Before-and-after study of all patients with thrombocytopenia was used.‘Before’group had no intervention.New standard operating procedures for thrombocytopenia management were introduced. In the‘After’group, bonemarrow aspiration; determination of fibrinogen dosage, prothrombin time, factor V, D-dimers; assay of fibrin monomers,ferritin, triglycerides, lactic acid dehydrogenase, aspartate transaminase, alanine aminotransferase, vitamin B12,folates,reticulocytes, haptoglobin, and bilirubin were performed.Results:In the Before group (n= 20), the mechanism (central, peripheral, or mixed) was identified in 10 % versus 83%in After group (n=23)(p< 0.001) (48% peripheral, 35% mixed). Before intervention,≥1 etiology was identified in 15%versus 95.7% in the After group (p<0.001).Conclusions:Systematic and extensive investigation using routine tests highlights the mechanisms and etiology ofthrombocytopenia in most cases

Plasma antioxidant status in septic critically ill patients: a decrease over time

International audienceSevere septic states in humans are responsible for intense intravascular oxidative stress, which induces numerous adaptive mechanisms. We determined time sequence changes in total plasma antioxidant capacity (TAC) and major plasma antioxidant concentrations, which have not been fully explained in septic conditions. A cohort of 56 consecutive septic patients (septic shock n = 37, severe sepsis n = 19) and six healthy volunteers. We compared TAC and antioxidant levels in patients with one of two degrees of septic states, at the onset of illness, to those of healthy volunteers. Thereafter, over a 10-day follow-up, we observed daily the time sequence changes of the two septic populations in terms of TAC and antioxidants. At the onset, there was no difference between the three groups in terms of TAC values (healthy subjects 2.18 +/- 0.04; severe sepsis 2.03 +/- 0.07; septic shock 2.09 +/- 0.09), then an equivalent time decline was observed in the two septic populations whatever the severity. TAC was statistically linked to uric acid, proteins in particular albumin and bilirubin (multivariate analysis), but no correlation was found with any vitamin (A, C and E). A sharp and persistent decrease in vitamin C concentrations was underlined. TAC, unaffected at first, deteriorated over time whatever the severity of the infection in these critically ill patients. TAC, unable to distinguish severe sepsis and septic shock, is unlikely to be a particularly useful outcome measure

Receiver operating characteristic curve of serum procalcitonin (PCT) for the diagnosis of gram negative bacteremia in critically ill patients with clinical sepsis and blood cultures proven positive for bacterial species

Plain circles indicate PCT values and dashes represents the corresponding ROC curve assuming a normal distribution of the variable.<p><b>Copyright information:</b></p><p>Taken from "Serum procalcitonin elevation in critically ill patients at the onset of bacteremia caused by either gram negative or gram positive bacteria"</p><p>http://www.biomedcentral.com/1471-2334/8/38</p><p>BMC Infectious Diseases 2008;8():38-38.</p><p>Published online 26 Mar 2008</p><p>PMCID:PMC2289831.</p><p></p