Diagnosis and follow-up of infections in intensive care patients: value of C-reactive protein compared with other clinical and biological variables

Unexplained hypothermia is associated with bacterial infection in the Emergency Department

BACKGROUND

Early recognition and antibiotic therapy improve the prognosis of bacterial infections. Triage temperature in the Emergency department (ED) constitutes a diagnostic and prognostic marker of infection. The objective of this study was to assess the prevalence of community-acquired bacterial infections and the diagnostic ability of conventional biological markers in patients presenting to the ED with hypothermia.

METHODS

We conducted a retrospective single-center study over a 1-year period before the COVID-19 pandemic. Consecutive adult patients admitted to the ED with hypothermia (body temperature < 36.0 °C) were eligible. Patients with evident cause of hypothermia and patients with viral infections were excluded. Diagnosis of infection was based on the presence of at least two among the three following pre-defined criteria: (i) the presence of a potential source of infection, (ii) microbiology data, and (iii) patient outcome under antibiotic therapy. The association between traditional biomarkers (white blood cells, lymphocytes, C-reactive protein [CRP], Neutrophil to Lymphocyte Count Ratio [NLCR]) and underlying bacterial infections was evaluated using a univariate and a multivariate (logistic regression) analysis. Receiver operating characteristic curves were built to determine threshold values yielding the best sensitivity and specificity for each biomarker.

RESULTS

Of 490 patients admitted to the ED with hypothermia during the study period, 281 were excluded for circumstantial or viral origin, and 209 were finally studied (108 men; mean age: 73 ± 17 years). A bacterial infection was diagnosed in 59 patients (28%) and was mostly related to Gram-negative microorganisms (68%). The area under the curve (AUC) for the CRP level was 0.82 with a confidence interval (CI) ranging from 0.75 to 0.89. The AUC for the leukocyte, neutrophil and lymphocyte counts were 0.54 (CI: 0.45-0.64), 0.58 (CI: 0.48-0.68) and 0.74 (CI: 0.66-0.82), respectively. The AUC of NLCR and quick Sequential Organ Failure Assessment (qSOFA) reached 0.70 (CI: 0.61-0.79) and 0.61 (CI: 0.52-0.70), respectively. In the multivariate analysis, CRP ≥ 50 mg/L (OR: 9.39; 95% CI: 3.91-24.14; p < 0.01) and a NLCR ≥10 (OR: 2.73; 95% CI: 1.20-6.12; p = 0.02) were identified as independent variables associated with the diagnosis of underlying bacterial infection.

CONCLUSION

Community-acquired bacterial infections represent one third of diagnoses in an unselected population presenting to the ED with unexplained hypothermia. CRP level and NLCR appear useful for the diagnosis of causative bacterial infection.

Value of D-Dimer as a Diagnostic Marker of Infection Associated with Orthopedic Implants

Background:

Recently, the D-dimer biomarker has gained the researchers' attention for predicting infections. We aimed to determine the relationship between this marker and other inflammatory markers involved in orthopedic implant-associated infections.

Materials and Methods:

In this study, all patients diagnosed with an orthopedic implant-associated infection were investigated in 3 years. The serum level of D-dimer, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) was measured. Infection was diagnosed based on the clinical and culture results of biopsy samples.

Results:

The cultured microorganisms, detected in 26 patients with infections, included Staphylococcus aureus (n = 13, 50%), Staphylococcus epidermidis (n = 2, 7.7%), Klebsiella aerogenes (n = 8, 30.8%), and Pseudomonas aeruginosa (n = 3, 11. 5%). Based on laboratory findings, there was a significant difference in the CRP level and ESR (P = 0.001). Although the level of D-dimer was higher in infected patients, compared to the controls (992.6 ± 667.2 vs. 690.1 ± 250.2 ng/mL), the difference was not statistically significant. There was no significant correlation between the elevated D-dimer level and CRP level, whereas ESR had a positive correlation with the elevated D-dimer level (r = 0.6, P = 0.03). The sensitivity, specificity, and positive predictive value (PPV) of D-dimer in the prediction of infection were 65%, 57%, and 45%, respectively. Furthermore, the sensitivity, specificity, and PPV of CRP were 100%, 92.3%, and 95%, respectively, whereas the corresponding values for ESR were 85%, 69.2%, and 62%, respectively.

Conclusion:

Measurement of the serum D-dimer level is not efficient for the diagnosis of orthopedic implant-associated infections due to its low predictive value. Furthermore, there was no significant correlation between the serum D-dimer level and CRP.

Diagnostic Accuracy and Prognostic Value of Neutrophil-to-Lymphocyte and Platelet-to-Lymphocyte Ratios in Septic Patients outside the Intensive Care Unit

Background and Objectives: The aim of this study was to evaluate the diagnostic accuracy and prognostic value of neutrophil-to-lymphocyte (NLR) and platelet-to-lymphocyte (PLR) ratios and to compare them with other biomarkers and clinical scores of sepsis outside the intensive care unit. Materials and methods: In this retrospective study, 251 patients with sepsis and 126 patients with infection other than sepsis were enrolled. NLR and PLR were calculated as the ratio between absolute values of neutrophils, lymphocytes, and platelets by complete blood counts performed on whole blood by Sysmex XE-9000 (Dasit, Italy) following the manufacturer’s instruction. Results: The best NLR value in diagnosis of sepsis was 7.97 with sensibility, specificity, AUC, PPV, and NPV of 64.26%, 80.16%, 0.74 (p < 0.001), 86.49%, and 53.18%, respectively. The diagnostic role of NLR significantly increases when PLR, C-reactive protein (PCR), procalcitonin (PCT), and mid-regional pro-adrenomedullin (MR-proADM) values, as well as systemic inflammatory re-sponse syndrome (SIRS), sequential organ failure assessment (SOFA), and quick-sequential organ failure assessment (qSOFA) scores, were added to the model. The best value of NLR in predicting 90-day mortality was 9.05 with sensibility, specificity, AUC, PPV, and NPV of 69.57%, 61.44%, 0.66 (p < 0.0001), 28.9%, and 89.9%, respectively. Sensibility, specificity, AUC, PPV, and NPV of NLR increase if PLR, PCR, PCT, MR-proADM, SIRS, qSOFA, and SOFA scores are added to NLR. Conclusions: NLR and PLR represent a widely useful and cheap tool in diagnosis and in predict-ing 90-day mortality in patients with sepsis.

A randomized trial to compare procalcitonin and C-reactive protein in assessing severity of sepsis and in guiding antibacterial therapy in Egyptian critically ill patients

BACKGROUND

Procalcitonin (PCT) and C-reactive protein (CRP) are the main used biomarkers for sepsis and in guiding antibiotic therapy, although PCT high cost limits its use in developing countries.

OBJECTIVE

Comparing between PCT and CRP in assessing severity of sepsis and in guiding antibacterial therapy in critically ill patients.

METHODS

In a prospective randomized study, 60 patients were included from an Egyptian Intensive Care Unit. Patients were divided into CRP and PCT groups. CRP and PCT were measured at baseline and on days 4 and 7. Validity, sensitivity, and specificity of both biomarkers and their correlation with sepsis scores (Acute Physiology and Chronic Health Evaluation II (APACHE II) and Sepsis-related Organ Failure Assessment (SOFA)) were evaluated. Antibacterial continuation at days 4 and 7 was assessed.

RESULTS

The diagnostic accuracy, specificity, and sensitivity of PCT were higher than CRP (80.79% vs 69.45%, 36% vs 28.7%, 87.6% vs 72.4%, respectively). PCT levels were significantly correlated with APACHE II score (P ≤ 0.0001) and SOFA score (P = 0.005), while CRP levels were not correlated with APACHEII and SOFA scores,(P > 0.05). PCT was associated with less antibacterial exposure (33% stopped their antibiotics on day 4 versus 6% in CRP, P = 0.009). Only 33% continued their antibacterial regimen in PCT group after 7 days versus 83% in CRP group (*P ≤ 0.0001).

CONCLUSION

PCT is a more accurate diagnostic and prognostic biomarker than CRP in patients with sepsis. PCT significantly shortened patients' exposure to antibacterial therapy and hospital length of stay.

The higher the better? Defining the optimal beta-lactam target for critically ill patients to reach infection resolution and improve outcome

OBJECTIVES

Beta-lactam antibiotics are often subject to therapeutic drug monitoring, but breakpoints of target attainment are mostly based on expert opinions. Studies that show a correlation between target attainment and infection resolution are missing. This analysis investigated whether there is a difference in infection resolution based on two breakpoints of target attainment.

METHODS

An outcome group out of 1392 critically ill patients treated with meropenem or piperacillin-tazobactam was formed due to different selection criteria. Afterwards, three groups were created: group 1=free drug concentration (f) was < 100% of the time (T) above the minimal inhibitory concentration (MIC) (< 100% fT > MIC), group 2=100% fT > MIC < 4xMIC, and group 3=100% fT > 4xMIC. Parameters for infection control, renal and liver function, and estimated and observed in-hospital mortality were compared between those groups. Statistical analysis was performed with one-way analysis of variance, Tukey post hoc test, U test, and bivariate logistic regression.

RESULTS

The outcome group consisted of 55 patients (groups 1-3, 17, 24, and 14 patients, respectively). Patients allocated to group 2 or 3 had a significantly faster reduction of the C-reactive protein in contrast to patients allocated to group 1 (p = 0.033 and p = 0.026). Patients allocated to group 3 had a worse renal function, a higher Acute Physiology and Chronic Health Evaluation (APACHE II) score, were older, and had a significantly higher in-hospital mortality compared to group 1 (p = 0.017) and group 2 (p = 0.001). The higher mortality was significantly influenced by worse liver function, higher APACHE II, and higher Sequential Organ Failure Assessment (SOFA) score and norepinephrine therapy.

CONCLUSION

Achieving the target 100% fT > MIC leads to faster infection resolution in the critically ill. However, there was no benefit for patients who reached the highest target of 100% fT > 4xMIC, although the mortality rate was higher possibly due to confounding effects. In conclusion, we recommend the target 100% fT > MIC < 4xMIC for critically ill patients.

TRIAL REGISTRATION

NCT03985605.

Immature platelet indices alongside procalcitonin for sensitive and specific identification of bacteremia in the intensive care unit

Hematological markers that can be rapidly analyzed and regularly monitored during a patient's stay on ICU, and that can identify bacterial causes of sepsis are being extensively sought. The significance of platelets in early immunological responses provides justification for assessing their usefulness in the identification of bacteremia amongst sepsis patients. In this preliminary study, the full blood count, including the platelet count by impedance (PLT-I), Immature Platelet Fraction (IPF%) and absolute immature platelet count (AIPC), were analyzed in eighty-two sepsis patients daily over the first 5 days stay on ICU. C-Reactive Protein (CRP), procalcitonin (PCT), and lactate were also analyzed daily. Blood cultures confirmed or excluded the presence of bacteremia. PCT provided the earliest indicator of bacteremia, with significant differences between the two cohorts on day 1. The change in IPF% and AIPC from day 1 to day 2 (Δ IPF% and Δ AIPC) provided the most accurate indication; A combination of Δ IPF% and day 2 PCT, provided a positive predictive value and negative predictive value of 100% and 96.10%, respectively. These data provide strong justification for larger multi-center validation studies to confirm the usefulness of these platelet indices during the assessment of sepsis on the ICU.

Difference in hematocrit and plasma albumin levels as an additional biomarker in the diagnosis of infectious disease

INTRODUCTION

In clinical practice, it has been observed that patients with severe infections show changes to their hematocrit (HCT) and serum albumin (ALB) levels. This study aimed to evaluate whether the difference of HCT and ALB (HCT-ALB) levels can be used as an additional biomarker for fast diagnosis of severe infections.

MATERIAL AND METHODS

This was a retrospective case-control study which included adult patients with severe infections, patients with non-infective conditions and healthy individuals. A total of 7,117 individuals were recruited in Yunnan Province, China, from January 2012 to January 2018, and were divided into three groups: 1,033 patients with severe infections (group 1); 1,081 patients with non-infective conditions (group 2); and 5,003 healthy individuals from the general population (group 3). The potential diagnostic threshold of HCT-ALB for severe infectious patients was determined by the receiver operating characteristic (ROC) curve analysis. Group 3 was used as the reference to draw the ROC curves of the HCT-ALB value in group 1 or group 2.

RESULTS

HCT-ALB values in each group were significantly different. We found that the area under the ROC curve (AUC) of group 1 reached 0.87 (95% CI: 0.86-0.89), whereas the AUC of group 2 was 0.60 (95% CI: 0.58-0.62). To reach a higher specificity of 99.0% (95% CI: 98.8-99.3%, and with sensitivity of 37.5%, 95% CI: 34.5-40.5%), a HCT-ALB value of 10.25 was recommended as the standard for diagnosis of severe infection.

CONCLUSIONS

The HCT-ALB value was increased in patients with infectious disease. The measurement of the HCT-ALB value (> 10.25) might be useful in the fast diagnosis of infectious disease.

Neutrophil to lymphocyte ratio as a predictor of treatment response and mortality in septic shock patients in the intensive care unit

Background/aim

While C-reactive protein (CRP) is a well-studied marker for predicting treatment response and mortality in sepsis, it was aimed to assess the efficacy of the neutrophil lymphocyte ratio (NLR) as a predictor of mortality and treatment response in sepsis patients in the intensive care unit (ICU).

Materials and methods

In this retrospective cross-sectional study, sepsis patients were divided according to the presence of septic shock on the 1st day of ICU stay, and then subgrouped according to mortality. Patient demographics, acute physiologic and chronic health evaluation II and sequential organ failure assessment scores, NLR and CRP (on the 1st, 3rd, and last day in the ICU), microbiology data, antibiotic responses, ICU data, and mortality were recorded. Receiver operating characteristic (ROC) curves for the area under curve (AUC) were calculated for the inflammatory markers and ICU severity scores for mortality.

Results

Of the 591 (65% male) enrolled patients, 111 (18.8%) were nonsurvivors with shock, 117 (19.8%) were survivors with shock, 330 (55.8%) were survivors without shock, and 33 (5.6%) were nonsurvivors without shock. On the 1st day of ICU stay, the NLR and CRP were similar in all of the groups. On the 3rd day of antibiotic response, the NLR was increased (11.8) in the nonresponsive patients when compared with the partially responsive (11.0) and responsive (8.5) patients. If the NLR was ≥15 on the 3rd day, the mortality odds ratio was 6.96 (CI: 1.4–34.1, P < 0.017). The NLR and CRP on the 1st, 3rd, and last day of ICU stay (0.52, 0.58, 0.78 and 0.56, 0.70, 0.78, respectively) showed a similar increasing trend for mortality.

Conclusion

The NLR can predict mortality and antibiotic responsiveness in ICU patients with sepsis and septic shock. If the NLR is >15 on the 3rd day of postantibiotic initiation, the risk of mortality is high and treatment should be reviewed carefully.

Is Interleukin-6 a better predictor of successful antibiotic therapy than procalcitonin and C-reactive protein? A single center study in critically ill adults

Background

The aim of this study was to evaluate whether Interleukin-6 (IL-6) could be a faster indicator of treatment success in adults with severe sepsis and septic shock compared to procalcitonin (PCT) and C-reactive protein (CRP).

Methods

Data from adult patients with severe sepsis and septic shock managed at the medical intensive care unit (ICU) of the University Hospital Leipzig between September 2009 and January 2012 were analyzed retrospectively. Values for CRP, PCT and IL-6 on admission as well as after 24 and 48–72 h were collected. Antibiotic therapy was defined as clinically successful if the patient survived ICU stay.

Results

A total of 328 patients with severe sepsis and septic shock with adequate data quality were included. After 48–72 h, the median IL-6 was significantly lower in survivors than in non-survivors (114.2 pg/ml vs. 746.6 pg/ml; p < 0.001), while there was no significant difference for PCT (5.6 vs. 4.9 ng/ml; p = 0.586) and CRP (158.5 mg/l vs. 172.4 mg/l; p = 0.988).

Conclusions

The results of this study suggest that IL-6 is better than PCT and CRP in predicting the treatment success in predominantly non-surgical sepsis in the first 48–72 h.

Pathologic Difference between Sepsis and Bloodstream Infections

BACKGROUND

Sepsis, defined as life-threatening organ failure caused by a dysregulated host response to infection, is a major cause of morbidity and mortality in hospitalized patients. Understanding the features that distinguish sepsis from bloodstream infections (and other types of infection) can help clinicians appropriately and efficiently target their diagnostic workup and therapeutic interventions, especially early in the disease course.

CONTENT

In this review, sepsis and bloodstream infections are both defined, with a focus on recent changes in the sepsis definition. The molecular and cellular pathways involved in sepsis pathogenesis are described, including cytokines, the coagulation cascade, apoptosis, and mitochondrial dysfunction. Laboratory tests that have been evaluated for their utility in sepsis diagnosis are discussed.

SUMMARY

Sepsis is defined not only by the presence of an infection, but also by organ dysfunction from a dysregulated host response to that infection. Numerous pathways, including proinflammatory and antiinflammatory cytokines, the coagulation cascade, apoptosis, and mitochondrial dysfunction, help determine if a bloodstream infection (or any other infection) progresses to sepsis. Many biomarkers, including C-reactive protein, procalcitonin, and lactic acid have been evaluated for use in sepsis diagnosis, although none are routinely recommended for that purpose in current clinical practice. While some laboratory tests can help distinguish the 2, the presence of organ dysfunction is what separates sepsis from routine infections.

Nutritional biomarkers: Current view and future perspectives

There is a poor relationship between nutrient intake and existing nutritional biomarkers due to variety of factors affecting their sensitivity and specificity. To explore the impact of nutrients at molecular level and devising a sensitive biomarker, proteomics is a central technology with sirtuins as one of the most promising nutritional biomarker. Sirtuins (seven mammalian sirtuins reported so far) have been reported to perform protein deacetylases and ADP-ribosyltransferases activity. It is distributed in different cellular compartments thereby controlling several metabolic processes. Sirtuins are oxidized nicotinamide adenine dinucleotide dependent, which implicates a direct effect of the metabolic state of the cell on its activity. Calorie restriction upregulates the mammalian sirtuin protein levels in variety of tissues and organs where it acts upon both histone and nonhistone substrates. Sirtuin senses nutrient availability and impacts gluconeogenesis, glycolysis, and insulin sensitivity. It deacetylates and inhibits the nuclear receptor that activates fat synthesis and adipogenesis in the body, leading to fat loss and bringing favorable cellular and health changes. Sirtuins mediates intracellular response that promotes cell survival, DNA damage repair thereby increasing the cell longitivity. The activation of sirtuins brings a wide spectrum of other health benefits and its activity levels are indicative of nutritional status as well as disease progression in cancer, inflammation, obesity, cardiovascular diseases, and viral infections. There are several foods that activate sirtuin activity and offer significant health benefits by their consumption.

Diagnostic accuracy of procalcitonin, neutrophil-lymphocyte count ratio, C-reactive protein, and lactate in patients with suspected bacterial sepsis

Background

Early recognition is a key factor to achieve improved outcomes for septic patients. Combinations of biomarkers, as opposed to single ones, may improve timely diagnosis and survival. We investigated the performance characteristics of sepsis biomarkers, alone and in combination, for diagnosis of verified bacterial sepsis using Sepsis-2 and Sepsis-3 criteria, respectively.

Methods

Procalcitonin (PCT), neutrophil-lymphocyte count ratio (NLCR), C-reactive protein (CRP), and lactate were determined in a total of 1,572 episodes of adult patients admitted to the emergency department on suspicion of sepsis. All sampling were performed prior to antibiotic administration. Discriminant analysis was used to construct two composite biomarkers consisting of linear combinations of the investigated biomarkers, one including three selected biomarkers (i.e., NLCR, CRP, and lactate), and another including all four (i.e., PCT, NLCR, CRP, and lactate). The diagnostic performances of the composite biomarkers as well as the individual biomarkers were compared using the area under the receiver operating characteristic curve (AUC).

Results

For diagnosis of bacterial sepsis based on Sepsis-3 criteria, the AUC for PCT (0.68; 95% CI 0.65–0.71) was comparable to the AUCs for the both composite biomarkers. Using the Sepsis-2 criteria for bacterial sepsis diagnosis, the AUC for the NLCR (0.68; 95% CI 0.65–0.71) but not for the other single biomarkers, was equal to the AUCs for the both composite biomarkers. For diagnosis of severe bacterial sepsis or septic shock based on the Sepsis-2 criteria, the AUCs for both composite biomarkers were significantly greater than those of the single biomarkers (0.85; 95% CI 0.82–0.88 for the composite three-biomarker, and 0.86; 95% CI 0.83–0.89 for the composite four-biomarker).

Conclusions

Combinations of biomarkers can improve the diagnosis of verified bacterial sepsis in the most critically ill patients, but in less severe septic conditions either the NLCR or PCT alone exhibit equivalent performance.

Diagnosing sepsis - The role of laboratory medicine

Sepsis is the host response to microbial pathogens resulting in significant morbidity and mortality. An accurate and timely diagnosis of sepsis allows prompt and appropriate treatment. This review discusses laboratory testing for sepsis because differentiating systemic inflammation from infection is challenging. Procalcitonin (PCT) is currently an FDA approved test to aid in the diagnosis of sepsis but with questionable efficacy. However, studies support the use of PCT for antibiotic de-escalation. Serial lactate measurements have been recommended for monitoring treatment efficacy as part of sepsis bundles. The 2016 sepsis consensus definitions include lactate concentrations >2mmol/L (>18mg/dL) as part of the definition of septic shock. Also included in the 2016 definitions are measuring bilirubin and creatinine to determine progression of organ failure indicating worse prognosis. Hematologic parameters, including a simple white blood cell count and differential, are frequently part of the initial sepsis diagnostic protocols. Several new biomarkers have been proposed to diagnose sepsis or to predict mortality, but they currently lack sufficient sensitivity and specificity to be considered as stand-alone testing. If sepsis is suspected, new technologies and microbiologic assays allow rapid and specific identification of pathogens. In 2016 there is no single laboratory test that accurately diagnoses sepsis.

Laboratory detection of sepsis: biomarkers and molecular approaches

Sepsis, severe sepsis, and septic shock cause significant morbidity and mortality worldwide. Rapid diagnosis and therapeutic interventions are desirable to improve the overall mortality in patients with sepsis. However, gold standard laboratory diagnostic methods for sepsis, pose a significant challenge to rapid diagnosis of sepsis by physicians and laboratories. This article discusses the usefulness and potential of biomarkers and molecular test methods for a more rapid clinical and laboratory diagnosis of sepsis. Because new technologies are quickly emerging, physicians and laboratories must appreciate the key factors and characteristics that affect the clinical usefulness and diagnostic accuracy of these test methodologies.

Interpretation of C-reactive protein concentrations in critically ill patients

Infection is often difficult to recognize in critically ill patients because of the marked coexisting inflammatory process. Lack of early recognition prevents timely resuscitation and effective antimicrobial therapy, resulting in increased morbidity and mortality. Measurement of a biomarker, such as C-reactive protein (CRP) concentration, in addition to history and physical signs, could facilitate diagnosis. Although frequently measured in clinical practice, few studies have reported on the pathophysiological role of this biomarker and its predictive value in critically ill patients. In this review, we discuss the pathophysiological role of CRP and its potential interpretation in the inflammatory processes observed in critically ill patients.

Sepsis in AIDS patients: clinical, etiological and inflammatory characteristics

INTRODUCTION

Intensive care mortality of HIV-positive patients has progressively decreased. However, critically ill HIV-positive patients with sepsis present a worse prognosis. To better understand this condition, we propose a study comparing clinical, etiological and inflammatory data, and the hospital course of HIV-positive and HIV-negative patients with severe sepsis or septic shock.

METHODS

A prospective observational study enrolling patients with severe sepsis or septic shock associated or not with HIV infection, and admitted to intensive care unit (ICU). Clinical, microbiological and inflammatory parameters were assessed, including C-reactive protein (CRP), procalcitonin (PCT), interleukin-6, interleukin-10 and TNF-α. Outcome measures were in-hospital and six-month mortality.

RESULTS

The study included 58 patients with severe sepsis/septic shock admitted to ICU, 36 HIV-positive and 22 HIV-negative. All HIV-positive patients met the criteria for AIDS (CDC/2008). The main foci of infection in HIV-positive patients were pulmonary and abdominal (p=0.001). Fungi and mycobacteria were identified in 44.4% and 16.7% of HIV-positive patients, respectively. In contrast, the main etiologies for sepsis in HIV-negative patients were Gram-negative bacilli (36.4%) and Gram-positive cocci (36.4%) (p=0.001). CRP and PCT admission concentrations were lower in HIV-positive patients (130 vs. 168 mg/dL p=0.005, and 1.19 vs. 4.06 ng/mL p=0.04, respectively), with a progressive decrease in surviving patients. Initial IL-10 concentrations were higher in HIV-positive patients (4.4 pg/mL vs. 1.0 pg/mL, p=0.005), with moderate accuracy for predicting death (area under receiver-operating characteristic curve =0.74). In-hospital and six-month mortality were higher in HIV-positive patients (55.6 vs. 27.3% p=0.03, and 58.3 vs. 27.3% p=0.02, respectively).

CONCLUSIONS

The course of sepsis was more severe in HIV-positive patients, with distinct clinical, etiological and inflammatory characteristics.

C-reactive protein as a predictor of mortality in patients affected with severe sepsis in intensive care unit

BACKGROUND

Severe sepsis is a primary cause of morbidity and mortality in the intensive care unit (ICU). Numerous biomarkers have been assessed to predict outcome and CRP is widely used. However, the relevance for mortality risk of the CRP level and the day when it is measured have not been well studied. We aimed to assess whether initial and/or third dayCRP values are as good predictors of mortality in ICU patients with severe sepsis as other well-known complex predictors of mortality, i.e., SOFA scores.

METHODS

An observational cohort study was performed in a 20-bed respiratory ICU in a chest disease center. Patients with severe sepsis due to respiratory disease were enrolled in the study. SOFA scores, CRP values on admission and on the third day of hospital stay, and mortality rate were recorded. ROC curves for SOFA scores and CRP values were calculated.

RESULTS

The study included 314 ICU patients with sepsis admitted between January 2009 and March 2010. The mortality rate was 14.2% (n = 45). The area under the curve (AUC) for CRP values and SOFA scores on admission and on the 3rd day in ICU were calculated as 0.57 (CI: 0.48-0.66); 0.72 (CI: 0.63-0.80); 0.72 (CI: 0.64-0.81); and 0.76 (CI: 0.67-0.86), respectively. Sepsis due to nosocomial infection, a CRP value > 100 mg/L and higher SOFA scores on 3rd day, were found to be risk factors for mortality (odds ratio [OR]: 3.76, confidence interval [CI]: 1.68-8.40, p < 0.001, OR: 2.70, CI: 1.41-2.01, p < 0.013, and OR: 1.68, CI: 1.41-2.01, p < 0.0001, respectively).

CONCLUSIONS

The risk of sepsis related mortality appears to be increased when the 3rd day CRP value is greater than 100 mg/dL. Thus, CRP appears to be as valuable a predictor of mortality as the SOFA score.

Discriminative value of inflammatory biomarkers for suspected sepsis

BACKGROUND

Circulating biomarkers can facilitate sepsis diagnosis, enabling early management and improved outcomes. Procalcitonin (PCT) has been suggested to have superior diagnostic utility compared to other biomarkers.

STUDY OBJECTIVES

To define the discriminative value of PCT, interleukin-6 (IL-6), and C-reactive protein (CRP) for suspected sepsis.

METHODS

PCT, CRP, and IL-6 were correlated with infection likelihood, sepsis severity, and septicemia. Multivariable models were constructed for length-of-stay and discharge to a higher level of care.

RESULTS

Of 336 enrolled subjects, 60% had definite infection, 13% possible infection, and 27% no infection. Of those with infection, 202 presented with sepsis, 28 with severe sepsis, and 17 with septic shock. Overall, 21% of subjects were septicemic. PCT, IL6, and CRP levels were higher in septicemia (median PCT 2.3 vs. 0.2 ng/mL; IL-6 178 vs. 72 pg/mL; CRP 106 vs. 62 mg/dL; p < 0.001). Biomarker concentrations increased with likelihood of infection and sepsis severity. Using receiver operating characteristic analysis, PCT best predicted septicemia (0.78 vs. IL-6 0.70 and CRP 0.67), but CRP better identified clinical infection (0.75 vs. PCT 0.71 and IL-6 0.69). A PCT cutoff of 0.5 ng/mL had 72.6% sensitivity and 69.5% specificity for bacteremia, as well as 40.7% sensitivity and 87.2% specificity for diagnosing infection. A combined clinical-biomarker model revealed that CRP was marginally associated with length of stay (p = 0.015), but no biomarker independently predicted discharge to a higher level of care.

CONCLUSIONS

In adult emergency department patients with suspected sepsis, PCT, IL-6, and CRP highly correlate with several infection parameters, but are inadequately discriminating to be used independently as diagnostic tools.

The use of prealbumin and C-reactive protein for monitoring nutrition support in adult patients receiving enteral nutrition in an urban medical center

BACKGROUND

Serum prealbumin (PAB) is commonly used to assess protein status and is often used to monitor the response to nutrition support. However, during inflammation, the liver synthesizes acute-phase proteins such as C-reactive protein (CRP) at the expense of PAB.

OBJECTIVE

The purpose of this retrospective study was to determine whether changes in PAB reflect the delivery of adequate nutrients or changes in inflammatory status in hospitalized adults (≥18 years) receiving enteral nutrition (n = 154).

METHODS

Protein and energy intake were compared to changes in PAB, assessed at baseline and twice weekly. C-reactive protein was assessed when PAB was <18 mg/dL to determine the presence and severity of inflammation.

RESULTS

In a sample of mostly critically ill patients, there was no significant difference in change in PAB for those receiving ≥60% of calorie needs (2.74 ± 9.50 mg/dL) compared to <60% of calorie needs (2.48 ± 9.36 mg/dL; P = .86). Changes in PAB correlated only with changes in CRP (r = -0.544, P < .001). In a subgroup analysis of 62 patients with repeated measures of PAB and CRP, PAB increased significantly only in the bottom 2 tertiles for calorie delivery and the lowest tertile for protein delivery.

CONCLUSIONS

These results indicate that PAB may not be a sensitive marker for evaluating the adequacy of nutrition support in critically ill patients with inflammation. Only change in CRP was able to significantly predict changes in PAB, suggesting that an improvement in inflammation, rather than nutrient intake, was responsible for the increases in PAB levels.

Solobacterium moorei bacteremia: identification, antimicrobial susceptibility, and clinical characteristics

We present five cases of Solobacterium moorei bacteremia. The isolates were identified with 16S rRNA gene sequencing and were susceptible to common antibiotics used for anaerobic infections. Bacteremia with S. moorei seems to be associated with debilitating conditions, but the prognosis of the infection appears to be good.

Factors associated with positive blood cultures in outpatients with suspected bacteremia

Blood cultures are routinely taken in outpatients with fever and suspected bacterial infections. However, in the majority of cases, they are not informative and of limited value for clinical decision making. The aim of this study was therefore to investigate factors associated with positive blood cultures in outpatients presenting to an outpatient clinic and emergency room. This was a case-control study of all outpatients with positive blood cultures from January 1, 2006 to October 31, 2007 and matched control patients with negative blood cultures in the same time period. Microbiology results and medical charts were reviewed to determine factors associated with positive blood cultures. The presence of a systemic inflammation response syndrome (SIRS) (OR 2.7, 95% Cl 1.0-7.2) and increased C-reactive protein (CRP) (OR 1.1 per 10 mg/l, 95% Cl 1.0-1.2) were the most powerful predictive values for the development of positive blood cultures. In positive cases serum albumin was lower (35 mg/l versus 39 mg/l) than in controls. SIRS, increasing CRP and low albumin were associated with positive blood cultures in outpatients. With simple clinical assessment and few laboratory tests indicative of infection, it is possible to define a group at higher risk for bacteremia in outpatients.

Lymphocytopenia and neutrophil-lymphocyte count ratio predict bacteremia better than conventional infection markers in an emergency care unit

Introduction

Absolute lymphocytopenia has been reported as a predictor of bacteremia in medical emergencies. Likewise, the neutrophil-lymphocyte count ratio (NLCR) has been shown a simple promising method to evaluate systemic inflammation in critically ill patients.

Methods

We retrospectively evaluated the ability of conventional infection markers, lymphocyte count and NLCR to predict bacteremia in adult patients admitted to the Emergency Department with suspected community-acquired bacteremia. The C-reactive protein (CRP) level, white blood cell (WBC) count, neutrophil count, lymphocyte count and NLCR were compared between patients with positive blood cultures (n = 92) and age-matched and gender-matched patients with negative blood cultures (n = 92) obtained upon Emergency Department admission.

Results

Significant differences between patients with positive and negative blood cultures were detected with respect to the CRP level (mean ± standard deviation 176 ± 138 mg/l vs. 116 ± 103 mg/l; P = 0.042), lymphocyte count (0.8 ± 0.5 × 10⁹/l vs. 1.2 ± 0.7 × 10⁹/l; P < 0.0001) and NLCR (20.9 ± 13.3 vs. 13.2 ± 14.1; P < 0.0001) but not regarding WBC count and neutrophil count. Sensitivity, specificity, positive and negative predictive values were highest for the NLCR (77.2%, 63.0%, 67.6% and 73.4%, respectively). The area under the receiver operating characteristic curve was highest for the lymphocyte count (0.73; confidence interval: 0.66 to 0.80) and the NLCR (0.73; 0.66 to 0.81).

Conclusions

In an emergency care setting, both lymphocytopenia and NLCR are better predictors of bacteremia than routine parameters like CRP level, WBC count and neutrophil count. Attention to these markers is easy to integrate in daily practice and without extra costs.

Is dental treatment of an infected tooth a risk factor for locally invasive spread of infection?

PURPOSE

To determine the impact of antecedent dental procedures and dental health on the course of odontogenic maxillofacial infections requiring hospital care.

PATIENTS AND METHODS

In this retrospective cohort study in a referral center, we evaluated medical records and panoramic radiographs of all patients admitted because of odontogenic maxillofacial infection (n = 84). The predictor variables were preceding dental treatment, antimicrobial therapy, and dental health. The outcome variables comprised infection parameters, length of stay, need for intensive care, and management during hospitalization.

RESULTS

The mean age of the patients was 43.2 ± 16.5 years and 60% were men. Dental procedure preceded the spread of the infection in 49 cases (58%): endodontic treatment (n = 22), tooth extraction (n = 19), and minor first aid (n = 8). Twenty-seven patients had not received any dental or antimicrobial treatment in the recent past. Antimicrobial treatment alone had been given to 8 patients. Patients without preceding treatment had the highest C-reactive protein levels on admission and at maximum (P = .020 and P = .011) and the highest white blood cell counts on admission (P = .011). Their length of stay was also longer, and they needed intensive care more often than the other patients. Maximum C-reactive protein levels and white blood cell counts between treatment groups did not significantly differ from each other.

CONCLUSIONS

The systemic response to the infection was strongest and the course of the infection most severe in the absence of preceding dental treatment and in patients with poor dental health. All types of dental treatment contributed to a less severe course of infection.

C-reactive protein: a tool in the follow-up of nosocomial pneumonia

OBJECTIVES

The aim of this study was to examine the clinical usefulness of serial C-reactive protein (CRP) dosages in patients with nosocomial pneumonia (NP).

METHODS

Prospective and observational study performed in a 24-beds Intensive Care Unit. Sixty four patients with NP, including non-ventilated patients and those with ventilator-associated pneumonia were included. Daily measurements of CRP were performed and CRP ratios were calculated from the day of antibiotic prescription (D0) until day 10. Patients were than classified according to the CRP ratios in 2 groups: 'good' response (CRP ratios lower than 0.67 at day 10) and 'poor' response (non-response or bi-phasic response).

RESULTS

The poor response group (n = 34) had a mortality rate of 53% in comparison to 20% in the good response group (n = 30) (RR = 2.65; 95% CI, 1.21-5.79, p = 0.01). Significant differences between the two groups were found on CRP ratios at Day 4 (p = 0.01). The adequacy of antibiotic therapy was much lower in the group poor response in comparison to the group good response, 14% vs. 67% (p = 0.008), respectively.

CONCLUSIONS

Daily CRP measurements in patients with nosocomial pneumonia may be useful in the identification of patients with poor outcome, as early as day 4, and detect patients with inappropriate antimicrobial therapy.

Sepsis redefined: the search for surrogate markers

Sepsis is a common and severe medical condition with substantial associated morbidity, mortality and cost. Furthermore, the incidence of sepsis has been rising annually over the past three decades, and morbidity and mortality remain high. The management of sepsis is further complicated by its very heterogeneous nature. This extends not only to the offending pathogens, but also to the nature and severity of the host response as well as its clinical manifestations. Efforts to identify surrogate markers for sepsis have therefore been an ongoing struggle. In this article we present some insights into various sepsis markers through history, presenting advantages and caveats associated with their use and interpretation. We also discuss the state of functional genomics, a relatively recent technological advancement that has already begun to change our understanding of sepsis pathophysiology, and offer new directions in the development of a more sensitive and specific sepsis biomarker.

C-reactive protein is not a useful indicator for infection in surgical intensive care units

CONTEXT AND OBJECTIVE

C-reactive protein (CRP) is commonly used as a marker for inflammatory states and for early identification of infection. This study aimed to investigate CRP as a marker for infection in patients with postoperative septic shock.

DESIGN AND SETTING

Prospective, single-center study, developed in a surgical intensive care unit at Hospital das Clínicas, Faculdade de Medicina da Universidade de São Paulo.

METHODS

This study evaluated 54 patients in the postoperative period, of whom 29 had septic shock (SS group) and 25 had systemic inflammatory response syndrome (SIRS group). All of the patients were monitored over a seven-day period using the Sequential Organ Failure Assessment (SOFA) score and daily CRP and lactate measurements.

RESULTS

The daily CRP measurements did not differ between the groups. There was no correlation between CRP and lactate levels and the SOFA score in the groups. We observed that the plasma CRP concentrations were high in almost all of the patients. The patients presented an inflammatory state postoperatively in response to surgical aggression. This could explain the elevated CRP measurements, regardless of whether the patient was infected or not.

CONCLUSIONS

This study did not show any correlation between CRP and infection among patients with SIRS and septic shock during the early postoperative period.

[C-reactive protein as a marker of mortality in intensive care unit]

OBJECTIVE

To determine C-reactive protein (CRP) prognostic value and in patients admitted to the intensive care unit (ICU).

DESIGN

Retrospective cohort study.

PATIENTS

A total of 879 patients admitted to the ICU for any cause over a 2-year period and who were hospitalized at least for 24 hours were studied.

METHOD

CRP levels were determined on admission and the value of the APACHE II score at 24 hours. The CRP values were correlated with APACHE II score along with other variables (gender, age, disease at onset, length of stay).

RESULTS

The highest CRP levels were those from subjects admitted for an infectious disease or shock-sepsis-multiple organ failure. Patients with CRP values greater than 10 mg/dl were older, had higher APACHE II score, remained hospitalized for more time and the mortality rate was higher in this group (p < 0.0001). CRP predictive value for mortality was higher as it increased in level with a specificity of 72.3% when these were over 10 mg/dl.

CONCLUSIONS

CRP is an early and specific indicator of outcome, qualities that make it useful as a routine test of patients at admission to the ICU.

Changing clinical features of odontogenic maxillofacial infections

Odontogenic maxillofacial infections occasionally require hospital care. Our aim was to study whether the number and the clinical features of patients hospitalized due to odontogenic abscesses in a large hospital district in Finland had changed in one decade. A retrospective analysis of two 12-month study cohorts one decade apart from the same population base was conducted. The first cohort comprised 71 patients and the second cohort comprised 101 patients. The incidence of odontogenic infections requiring hospital care increased from 5.3 to 7.2 per 100,000 inhabitants. The need for intensive care increased significantly from 15% to 32%, and the maximal C-reactive protein levels were significantly higher in the latter cohort, 127 mg/L, compared to the first cohort, 104 mg/L. The proportion of previously healthy patients decreased significantly from 83% to 65%. Odontogenic maxillofacial infections have become more prevalent and more severe during the decade in our hospital district. An increasing proportion of patients had underlying diseases.

An Update on C-reactive Protein for Intensivists

This review aims to summarise the physiology of C-reactive protein (CRP), its possible roles and limitations as an inflammatory and infective marker in intensive care medicine, and also the emerging roles of CRP in the pathogenesis of cardiovascular and autoimmune diseases. Observational and animal studies on uses of CRP were retrieved from the PubMed database without any language restrictions. Quantitative data were not pooled because of the heterogeneity of patient characteristics and disparate ways in which CRP was studied. Serum CRP concentrations are determined by the synthetic rate of its production in the liver regulated predominantly by interleukin-6. It has a half-life of 19 hours and is relatively slow in its onset and offset in response to an acute inflammatory process when compared to procalcitonin. It has some favourable properties and limitations as an inflammatory marker. An elevated CRP concentration is not specific to infections and the absolute CRP concentrations cannot be used to differentiate between bacterial, fungal and severe viral infections. The dynamic response of CRP to therapy that aims to modify the underlying inflammatory process and the clinical context of a patient are of pivotal importance when CRP concentrations are interpreted. CRP is found to be a significant partaker and prognostic factor in a wide range of cardiovascular and chronic diseases. In summary, CRP concentration is an important prognostic factor of many acute and chronic diseases. Serial CRP measurements may be useful to reflect a patient's response to therapy that aims to modify the underlying inflammatory process.

Effect of 35 degrees C hypothermia on intracranial pressure and clinical outcome in patients with severe traumatic brain injury

BACKGROUND

From 1994, we have used therapeutic hypothermia in patients with severe traumatic brain injury (Glasgow Coma Scale scores of 5 or less). In 2000, we altered the target temperature to 35 degrees C from the former 33 degrees C, as our findings suggested that cooling to 35 degrees C is sufficient to control intracranial hypertension, and that hypothermia below 35 degrees C may predispose patients to persistent cumulative oxygen debt. We attempted to clarify whether 35 degrees C hypothermia has the same effect as 33 degrees C hypothermia in reducing intracranial hypertension and whether it is associated with fewer complications and improved outcomes.

METHODS

We compared intracranial pressure (ICP) and biochemical parameters in the 30 patients treated with 35 degrees C hypothermia (January 2000 to June 2005) with those in the 31 patients treated with 33 degrees C hypothermia (July 1994 to December 1999).

RESULTS

Patient characteristics were similar in the two groups. The mean temperature during hypothermia was 35.1 +/- 0.7 degrees C in the 35 degrees C hypothermia group and 33.4 +/- 0.8 degrees C in the 33 degrees C hypothermia group. Mean ICP was controlled under 20 mm Hg during hypothermia in both the 35 degrees C hypothermia and 33 degrees C hypothermia groups. The incidence of intracranial hypertension and low cerebral perfusion pressure did not differ between the two groups. The 35 degrees C hypothermic patients exhibited a significant improvement in the decline of serum potassium concentrations during hypothermia and in the increment of C-reactive protein after rewarming. The mortality rate and the incidence of systemic complications tended to be lower in the 35 degrees C group.

CONCLUSIONS

Cooling patients to 35 degrees C is safe and the ICP reduction effects of 35 degrees C hypothermia are similar to those of 33 degrees C hypothermia.

Comparison of C-reactive protein and serum amyloid a protein in septic shock patients

Septic shock is a severe inflammatory state caused by an infectious agent. Our purpose was to investigate serum amyloid A (SAA) protein and C-reactive protein (CRP) as inflammatory markers of septic shock patients. Here we evaluate 29 patients in postoperative period, with septic shock, in a prospective study developed in a surgical intensive care unit. All eligible patients were monitored over a 7-day period by sequential organ failure assessment (SOFA) score, daily CRP, SAA, and lactate measurements. CRP and SAA strongly correlated up to the fifth day of observation but were not good predictors of mortality in septic shock.

The time course of blood C-reactive protein concentrations in relation to the response to initial antimicrobial therapy in patients with sepsis

BACKGROUND

C-reactive protein (CRP) may be a useful marker of sepsis but its use in the evaluation of response to therapy remains poorly defined. The aim of this study was to define the time course of CRP levels in septic patients according to their response to initial antimicrobial treatment, and to search for possible correlations between CRP levels and other clinical and biological variables.

PATIENTS AND METHODS

This prospective, observational, multicenter study included all critically ill patients with sepsis admitted to two medico-surgical departments of intensive care in Brussels, Belgium during a 5-month period. CRP levels and standard clinical and biological variables were measured daily from the day of sepsis diagnosis until death, transfer to the general floor, or the seventh day, which ever came first. Patients were divided into three groups according to their clinical course: group 1--patients with a favorable response to initial antibiotic therapy; group 2--patients who required a change in antibiotic therapy; group 3--patients who needed a procedure to control the infection.

RESULTS

CRP concentrations decreased more rapidly and to a greater degree in group 1 than in group 2 patients (p=0.001). An increase in CRP of at least 2.2 mg/dl in the first 48 h was associated with ineffective initial antibiotic therapy with a sensitivity of 77% and a specificity of 67%. No correlation was found between CRP levels and other clinical and biological variables.

CONCLUSION

Changes in CRP levels over the first 48 h of therapy can help to evaluate the response to initial antimicrobial therapy in septic patients.

A prospective evaluation of the Infection Probability Score (IPS) in the intensive care unit

OBJECTIVES

Identification of infection remains a major challenge, particularly in acutely ill patients. The Infection Probability Score (IPS) was developed to help rule out infection in acutely ill patients. In the present study, we determined the IPS in acutely ill, intensive care unit (ICU) patients to assess its use in the diagnosis and treatment of infection.

METHODS

In this prospective, observational study, we enrolled 107 consecutive patients who were admitted to the ICU without antibiotic therapy. Patients were allocated to four groups according to the probability of infection determined from clinical and microbiological data and their IPS values were then evaluated daily throughout the ICU stay.

RESULTS

The IPS was higher in patients with the highest clinical probability of infection and decreased significantly in these patients after 5 days of effective antimicrobial therapy. The IPS remained below the cut-off value in non-infected patients. Patients in whom inadequate antimicrobial therapy was administered had a greater mortality than the other patients.

CONCLUSIONS

The IPS had a good predictive value for diagnosis of infection. In addition, dynamic evaluation of this score may help to assess the response to therapy.

Dynamics of C-reactive protein and white blood cell count in critically ill patients with nosocomial Gram positive vs. Gram negative bacteremia: a historical cohort study

Background

Nosocomial bacteremia is associated with a poor prognosis. Early adequate therapy has been shown to improve outcome. Consequently, rapid detection of a beginning sepsis is therefore of the utmost importance. This historical cohort study was designed to evaluate if different patterns can be observed in either C-reactive protein (CRP) and white blood cell count (WCC) between Gram positive bacteremia (GPB) vs. Gram negative bacteremia (GNB), and to assess the potential benefit of serial measurements of both biomarkers in terms of early antimicrobial therapy initiation.

Methods

A historical study (2003–2004) was conducted, including all adult intensive care unit patients with a nosocomial bacteremia. CRP and WCC count measurements were recorded daily from two days prior (d_-2) until one day after onset of bacteremia (d₊₁). Delta (Δ) CRP and Δ WCC levels from the level at d_-2 onward were calculated.

Results

CRP levels and WCC counts were substantially higher in patients with GNB. Logistic regression analysis demonstrated that GNB and Acute Physiology and Chronic Health Evaluation (APACHE) II score were independently associated with a CRP increase of 5 mg/dL from d_-2 to d₊₁, and both were also independently associated with an increase of WCC levels from d_-2 to d₊₁ of 5,000 × 10³ cells/mm³.

Conclusion

Increased levels of CRP and WCC are suggestive for GNB, while almost unchanged CRP and WCC levels are observed in patients with GPB. However, despite the different patterns observed, antimicrobial treatment as such cannot be guided based on both biomarkers.

C-reactive protein concentration as a predictor of intensive care unit readmission: a nested case-control study

PURPOSE

The purpose of this study is to assess the ability of potential clinical predictors and inflammatory markers to predict intensive care unit (ICU) readmission during the same hospitalization.

MATERIALS AND METHODS

A nested case-control study utilized prospectively collected de-identified data of a 22-bed multidisciplinary ICU in a university hospital.

RESULTS

There were 1,405 consecutive ICU admissions in 2004, and of these, 18 were regarded as ICU readmissions (1.3%). The destination and timing of ICU discharge, the Sequential Organ Failure Assessment scores, white cell counts, and fibrinogen concentrations at discharge were not associated with ICU readmission. C-reactive protein (CRP) concentration within 24 hours before ICU discharge was associated with ICU readmission (mean CRP concentrations of cases vs controls, 177.8 vs 56.5 mg/L, respectively; P < .0001). The results remained unchanged after adjustment with the propensity scores. The area under the receiver operating characteristic curve for the CRP concentrations to predict ICU readmission was 0.884 (95% confidence interval, 0.765-0.999; P < .0001). Patients readmitted to the ICU had a higher predicted mortality in their second ICU admission (34.9% vs 26.1%; P < .01) and a longer total hospital stay (33.3 vs 20.3 days; P < .003) than patients without ICU readmission.

CONCLUSIONS

A high CRP concentration within 24 hours before ICU discharge is associated with a higher risk of readmission to the ICU.

Clinical laboratory findings associated with in-hospital mortality

The diagnostic approach and the clinical management of critically ill patients is challenging. The recognition of biomarkers related to in-hospital mortality is of importance for identification of patients at increased risk of death. Many prediction models assessing the severity of illness and likelihood of hospital survival were developed using logistic regression analyses. These models include several laboratory parameters, such as white blood cell counts, serum bilirubin, serum albumin, blood glucose, serum electrolytes and markers which reflect acid-base disturbances. Recently, several other biomarkers, including troponin, B-type natriuretic peptide (BNP), N-terminal proBNP, C-reactive protein, procalcitonin, cholesterol and coagulation related markers have emerged as clinically useful tools for risk stratification and mortality prediction of heterogeneous and more specific subgroups of critically ill patients. More investigations are required to verify whether risk stratification based on mortality-related biomarkers may translate into targeted treatment strategies to improve clinical outcome of the critical illness. Biomarkers which are related to in-hospital mortality are highlighted in the current review.

Effects of single dose of dexamethasone on patients with systemic inflammatory response

CONTEXT AND OBJECTIVE

Systemic inflammatory response syndrome (SIRS) is a very common condition among critically ill patients. SIRS, sepsis, septic shock and multiple organ dysfunction syndrome (MODS) can lead to death. Our aim was to investigate the efficacy of a single dose of dexamethasone for blocking the progression of systemic inflammatory response syndrome.

DESIGN AND SETTING

Prospective, randomized, double-blind, single-center study in a postoperative intensive care unit (Surgical Support Unit) at Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo.

METHODS

The study involved 29 patients with SIRS. All eligible patients were prospectively randomized to receive either a single dose of 0.2 mg/kg of dexamethasone or placebo, after SIRS was diagnosed. The patients were monitored over a seven-day period using Sequential Organ Failure Assessment score (SOFA).

RESULTS

The respiratory system showed an improvement on the first day after dexamethasone was administered, demonstrated by the improved PaO2/FiO2 ratio (p < 0.05). The cardiovascular system of patients requiring vasopressor therapy also improved over the first two days, with a better evolution in the dexamethasone group (p < 0.05). Non-surviving patients presented higher lactate assays than did survivors (p < 0.05) during this period.

CONCLUSIONS

Dexamethasone enhanced the effects of vasopressor drugs and evaluation of the respiratory system showed improvements (better PaO2/FiO2 ratio), one day after its administration. Despite these improvements, the single dose of dexamethasone did not block the evolution of SIRS.

[Serum C-reactive protein as a marker of outcome and infection in critical care patients]

BACKGROUND AND OBJECTIVE

C-reactive protein (CRP) has been considered a marker for infection and an aid for diagnosing sepsis. We analyze the relation of CRP to infection and outcome in intensive care units (ICU) patients.

PATIENTS AND METHOD

Prospective study on 77 ventilated patients. Expected short ICU stay or (suspected or confirmed) infection at admission were excluding criteria. 55 admissions after elective surgery were the controls. CRP measurement the first (CRP-1), third (CRP-3) and sixth (CRP-6) day of stay. APACHE II (Acute Physiology Score and Chronic Health Evaluation), SOFA (Sepsis-related Organ Failure Assessment), shock, respiratory or renal failure, leucocytes, platelets and albumin were registered. Follow-up until day 9 for infection and ICU discharge for outcome.

RESULTS

CRP-1 in controls was 5.3 (3.9) mg/l and cases 67.8 (77.4) (p < 0.001). Shock on admission was related to CRP-1: patients in shock had higher CRP-1 levels (118.6 [82.8] vs 62.8 [75.6]; p = 0.06). 40.25% of cases developed infection, and CRP-1 levels were higher in this patients (88.8 [93.9] vs 53.8 [60.9]; p < 0.05). ROC area under curve was 0.6 with a sensibility of 23% and a specificity of 89% for a level of CRP-1 > 100. Mortality was 23.4% in cases and 1.8% in controls. Age, shock, APACHE II and SOFA were related to mortality, but CRP-1 did not. ROC area under curve for CRP-1 as mortality predictor in all patients was 0.62 (0.76 for APACHE II and 0.77 for SOFA) but only in cases was of 0.49 (0.69 for APACHE II and 0.67 for SOFA).

CONCLUSIONS

CRP level on admission is an useful marker for early infection but not for outcome in critically ill patients admited to the ICU.