Rising C-reactive protein and procalcitonin levels precede early complications after esophagectomy

BACKGROUND

Elective esophagectomy with gastric tube reconstruction carries a high risk for complications. Early and accurate diagnosis could improve patient management. Increased C-reactive protein (CRP) levels may be associated with any, surgical or infectious, complication and procalcitonin (PCT) specifically with infectious complications.

METHODS

We measured CRP and PCT on post-operative days 0, 1, 2, and 3 in 45 consecutive patients. Complications were recorded up to 10 days post-esophagectomy.

RESULTS

Twenty-eight patients developed a post-operative complication (5 surgical, 14 infectious, 9 combined surgical/infectious, including anastomotic leakage), presenting on day 3 or later. Elevated days 2 and 3 and a rise in CRP preceded the diagnosis of general or combined surgical/infectious complications (minimum area under the receiver operating characteristics curve (AUROC) 0.75, P = 0.006). Elevated day 3 PCT preceded combined complications (AUROC 0.86, P < 0.001). High day 1 and 3 PCT levels preceded anastomotic leakage (minimum AUROC 0.76, P = 0.005), as did the day 3 CRP levels and their increases (minimum AUROC 0.78, P = 0.002).

CONCLUSIONS

This small study suggests that high or increasing CRP levels may precede the clinical diagnosis of general or surgical/infectious complications after esophagectomy. Elevated PCT levels may more specifically and timely precede combined surgical/infectious complications mainly associated with anastomotic leakage.

Microalbuminuria: A novel biomarker of sepsis

CONTEXT

Diffused endothelial dysfunction in sepsis leads to an increase in systemic capillary permeability, the renal component manifesting as microalbuminuria. The degree of microalbuminuria correlates with the severity of the acute insult, the quantification of which may serve to predict sepsis and mortality in critically ill patients.

AIMS

To evaluate whether the degree of microalbuminuria could differentiate patients with sepsis from those without and predict mortality in critically ill patients.

SETTINGS AND DESIGN

Prospective, non-interventional study in a 20-bed Intensive Care Unit (ICU) of a tertiary care hospital.

METHODS AND MATERIALS

After exclusions, between Jan-May 2007, 94 consecutive adult patients were found eligible. Albumin-creatinine ratio (ACR, mg/g) was measured in urine samples collected on ICU admission (ACR1) and at 24 hours (ACR2).

RESULTS

PATIENTS WERE CLASSIFIED INTO TWO GROUPS: those with sepsis, severe sepsis and septic shock (n = 30) and those without sepsis [patients without systemic inflammatory response syndrome (SIRS) and with SIRS due to noninfectious causes] (n = 64). In the sepsis group, median ACR1 [206.5 (IQR129.7-506.1)] was significantly higher compared to the non sepsis group [76.4 (IQR29-167.1)] (P = 0.0016, Mann Whitney). The receiver operating characteristics (ROC) curve analysis showed that at a cut off value 124 mg/g, ACR1 may be able to discriminate between patients with and without sepsis with a sensitivity of 80%, specificity of 64.1%, positive predictive value (PPV) of 51.1% and negative predictive value (NPV) of 87.3%. The median ACR2 [154 (IQR114.4-395.3)] was significantly higher (P = 0.004) in nonsurvivors (n = 13) as compared to survivors [50.8 (IQR 21.6-144.7)]. The ROC curve analysis revealed that ACR2 at a cut-off of 99.6 mg/g could predict ICU mortality with sensitivity of 85%, specificity of 68% with a NPV of 97% and PPV of 30%.

CONCLUSION

Absence of significant microalbuminuria on ICU admission is unlikely to be associated with sepsis. At 24 hours, absence of elevated levels of microalbuminuria is strongly predictive of ICU survival, equivalent to the time-tested APACHE II scores.

Kinetics of inflammatory markers following cancer-related bowel and liver resection

BACKGROUND

Macrophage migration inhibitory factor (MIF) was originally described as a cytokine that inhibits migration of macrophages at the site of inflammation. Subsequently it was also identified as a stress-induced hormone released from the anterior pituitary lobe in response to some pro-inflammatory stimuli like endotoxins and tumour necrosis factor (TNF-α).

AIM

To compare postoperative changes in serum MIF levels of patients undergoing bowel and liver resections. It has clinical relevance to describe the kinetics of this crucial mediator of systemic inflammation in surgery.

METHODS

A total of 58 patients were studied over 4 years. Group A (28 patients) underwent only hepatic resection without enterotomy. Group B (30 patients) had bowel resection with enterotomy. MIF, IL-1β, IL-8, prealbumin, albumin, α1-glycoprotein, fibrinogen, and C-reactive protein levels were measured preoperatively, immediately following surgery, and postoperatively for three consecutive days. To evaluate organ functions, multiple organ dysfunction score was used.

RESULTS

A significantly higher level of MIF (4,505 pg/mL) was found in group A when compared to that of group B immediately following surgery. Other parameters monitored in this study were not statistically different between the two groups.

CONCLUSION

Higher elevations in MIF levels with liver resections, compared to bowel resections, might be attributable to MIF release from damaged liver cells. The presumably minimal endotoxin exposure during bowel surgery was either insufficient or inefficient to induce relevant MIF elevations in our patients. To fully delineate implications of this finding further studies are needed.

Low-dose hydrocortisone during severe sepsis: effects on microalbuminuria

OBJECTIVE

The aim of this study was to investigate the effect of low-dose hydrocortisone on glomerular permeability measured by the microalbuminuria to creatinine ratio (MACR) and on other markers of sepsis in severe septic patients.

DESIGN

Randomized prospective study.

SETTING

University intensive care unit.

PATIENTS

The study involved 40 patients with severe sepsis randomized into the hydrocortisone group (n = 20) and the standard therapy group (n = 20).

INTERVENTIONS

The hydrocortisone group received standard therapy plus a continuous infusion of hydrocortisone for 6 days, whereas the standard therapy group received only standard therapy.

MEASUREMENTS AND MAIN RESULTS

MACR, serum C-reactive protein, and procalcitonin concentrations were recorded every day from the day before the steroid therapy (T(0)) until the 6 days after (T(1), T(2), T(3), T(4), T(5), and T(6)). Concentrations in the hydrocortisone group and the standard therapy group were compared using Mann-Whitney test at each time. We also compared with Wilcoxon signed rank test the values determined in each group at T(0) with those at each subsequent time. Median MACR decreased from T(0) to T(6) in both patient groups; however, values were significantly lower in the hydrocortisone group from T(3) through to T(6). Median serum C-reactive protein also decreased from T(0) in both patient groups, with significantly lower values in the hydrocortisone group from T(3) through to T(6). There were no significant differences in procalcitonin between groups compared with baseline values or at any individual time point.

CONCLUSIONS

Low-dose hydrocortisone seems to reduce MACR and serum C-reactive protein but not procalcitonin in patients with severe sepsis. Further studies are needed to confirm these results and to understand the underlying molecular mechanisms.

Does microalbuminuria predict illness severity in critically ill patients on the intensive care unit? A systematic review

CONTEXT

Studies assessing the accuracy of microalbuminuria to predict illness severity on the intensive care unit have produced inconsistent results.

OBJECTIVE

To determine the diagnostic accuracy of microalbuminuria to predict illness severity in critically ill patients on the intensive care unit.

DATA SOURCE

MEDLINE (1951 to September 2004) and EMBASE (1980 to September 2004) electronic databases were searched for relevant studies. Reference lists of all abstracts were manually searched to identify studies not included in the electronic database.

STUDY SELECTION

Studies that prospectively evaluated the accuracy of microalbuminuria to predict illness severity and/or mortality probability in adult patients on the intensive care unit were selected.

DATA EXTRACTION

We included nine studies in the review. Data to evaluate methodological quality and results were abstracted.

DATA SYNTHESIS

The methodological quality of a number of studies was poor. Significant heterogeneity in the design and conduct of the studies circumvented the data being subjected to meta-analysis. Studies also differed in the timing of the index test, in the methods of quantifying microalbuminuria, and in the cutoff values used.

CONCLUSIONS

This descriptive analysis reveals that microalbuminuria may hold promise as a predictor of illness severity and mortality on the intensive care unit. However, future epidemiologic studies need to be conducted to determine the optimal timing as well as the threshold reference value for the urine albumin creatinine ratio in the adult intensive care unit population. Thereafter, multiple-center prospective epidemiologic studies must be conducted to confirm and validate the findings of these preliminary studies. Future studies should conform to the Standards for Reporting of Diagnostic Accuracy checklist in terms of study design, conduct, and reporting. Presently there is no evidence to warrant the use of this tool on the intensive care unit.

Does transthoracic compared to transhiatal resection alter the early postoperative course of oesophagectomy?

Several techniques for esophageal resections have been reported. However, clear clinical evidence is still lacking whether any of the procedures is superior to the others regarding morbidity and mortality in the early postoperative period. Two operative approaches for esophageal carcinoma, transhiatal and transthoracic, were compared with respect to operative morbidity, mortality and systemic inflammatory response. In our prospective study between 2000 and 2002 83 patients were investigated. In a retrospective post hoc analysis patients were divided into two groups due to the performed operational procedure, transhiatal (TH) or transthoracic (TT). Multiple Organ Dysfunction Score (MODS) was monitored daily (t1,t2,t3). Serum procalcitonin (PCT) levels were determined on admission to the ICU (t0), then 24 hourly (t24,t48,t72). Microalbuminuria (M:Cr) was measured before (tp), and after surgery (t0,t6,t24,t48,t72). For statistical analysis Wilcoxon rank sum test, Mann-Whitney U-test and chi-square test were used as appropriate. We examined 52 patients in the TH group, and 31 patients in the TT group. There was no significant difference between the two groups regarding age, male/female ratio, and SAPS II scores. Operations lasted significantly longer in the TT group: 375 (300-480) min compared to the TH group 240 375 (180-319) min, P < 0.001. ICU mortality was similar in both groups (TH: 46 survivors/6 non-survivors; TT: 27 survivors/4 non-survivors; P = 0.607, respectively). Daily MODS did not differ significantly between the two groups. The observed inflammatory markers (PCT and M:Cr) followed the pattern we described earlier, without significant difference. In this study there was no difference in the clinical and biochemical variables of the patients between the transthoracic and transhiatal groups. The observed early postoperative morbidity and mortality may indicate, that both procedures can be considered as procedures with similar postoperative risk.

Serum procalcitonin and C-reactive protein levels as markers of bacterial infection: a systematic review and meta-analysis

A meta-analysis was performed to evaluate the accuracy of determination of procalcitonin (PCT) and C-reactive protein (CRP) levels for the diagnosis of bacterial infection. The analysis included published studies that evaluated these markers for the diagnosis of bacterial infections in hospitalized patients. PCT level was more sensitive (88% [95% confidence interval [CI], 80%-93%] vs. 75% [95% CI, 62%-84%]) and more specific (81% [95% CI, 67%-90%] vs. 67% [95% CI, 56%-77%]) than CRP level for differentiating bacterial from noninfective causes of inflammation. The Q value for PCT markers was higher (0.82 vs. 0.73). The sensitivity for differentiating bacterial from viral infections was also higher for PCT markers (92% [95% CI, 86%-95%] vs. 86% [95% CI, 65%-95%]); the specificities were comparable (73% [95% CI, 42%-91%] vs. 70% [95% CI, 19%-96%]). The Q value was higher for PCT markers (0.89 vs. 0.83). PCT markers also had a higher positive likelihood ratio and lower negative likelihood ratio than did CRP markers in both groups. On the basis of this analysis, the diagnostic accuracy of PCT markers was higher than that of CRP markers among patients hospitalized for suspected bacterial infections.

Increased glomerular permeability and pulmonary dysfunction following major surgery: correlation of microalbuminuria and PaO/FiO ratio

BACKGROUND

The aim of our trial was to evaluate the ability of microalbuminuria as an indicator of outcome and to investigate its relationship with the postoperative respiratory dysfunction in the initial postoperative period in a high-risk patient group.

METHODS

In our prospective, observational study patients were consecutively recruited following elective oesophagectomy, total gastrectomy, Whipple-resection of the pancreas and liver resection due to tumour removal. Microalbuminuria (expressed as urine albumin:creatinine ratio, M:Cr) was measured before (tp), and after surgery (t0, t6, t24, t48, t72). Multiple Organ Dysfunction Scores were monitored on ICU admission than daily (t1, t2, t3). For statistical analysis, Wilcoxon's rank-sum test, Mann-Whitney's U-test, receiver operating characteristic curve analysis and Spearman's rho test were used as appropriate.

RESULTS

One hundred and forty patients (118 survivors and 22 non-survivors) were recruited. Significantly higher Multiple Organ Dysfunction Scores were observed in non-survivors throughout the study period (P < 0.001). Microalbuminuria (Cr) increased significantly (P < 0.01) on admission to the ICU (t0) compared with the preoperative levels, but levels returned to normal within 6 h and remained so for the rest of the study. There was a significant difference between survivors and non-survivors at t0 (P < 0.01). However the ROC curve indicated that M:Cr is not a reliable descriptor of outcome. Comparison of Cr values with the PaO2/FiO2 ratio showed an inverse relationship on admission, which remained so for t24 and t48.

CONCLUSION

M:Cr measured on admission to the ICU was significantly higher in non-survivors than in survivors, and also showed an inverse relationship with the PaO2/FiO2 ratio following extended abdominal surgery. However, on admission, M:Cr did not discriminate survivors from non-survivors. Further studies are required to evaluate the prognostic value of this test for postoperative patients with risk of respiratory failure.

Microalbuminuria does not reflect increased systemic capillary permeability in septic shock

OBJECTIVE

To investigate the correlation between microalbuminuria and extravascular lung water in patients in septic shock who require mechanical ventilation for severe respiratory failure.

DESIGN AND SETTING

Prospective, observational, clinical study in the 20-bed intensive care unit of a university hospital.

PATIENTS AND PARTICIPANTS

25 consecutive patients in septic shock and also in severe respiratory failure requiring mechanical ventilation.

INTERVENTIONS

Hemodynamic parameters and extravascular lung water were determined by single arterial thermodilution. Together with each hemodynamic measurement the PaO(2)/FIO(2) ratio and urinary microalbumin to creatinine ratio (M:Cr) was measured. Serum C-reactive protein (CRP) and procalcitonin (PCT) levels were also determined daily.

MEASUREMENTS AND RESULTS

The EVLW index was significantly higher than normal throughout the study. Microalbuminuria was in the normal range on entry and remained so for the rest of the study period. Serum PCT and CRP levels were significantly higher than normal at every assessment points. No significant correlation was found between M:Cr and either EVLW or PaO(2)/FIO(2).

CONCLUSIONS

In this study patients in septic shock with significantly elevated EVLW had normal urinary M:Cr, and there was no correlation between M:Cr and EWLV, and PaO(2)/FIO(2). Therefore based on the current results routine measurements of microalbuminuria to determine endothelial permeability cannot be recommended in critically ill patients.

Immunoluminometric detection of human procalcitonin

Procalcitonin is a normal precursor of the active hormone calcitonin; however, its level in blood is normally undetectable. Dramatically increased levels of procalcitonin have been found in severe systemic bacterial infections and, today, this molecule is considered to be one of the earliest inflammatory markers of sepsis. In spite of the large body of data, it is still uncertain how and from which tissues procalcitonin is released into the circulation. In our experiments, we tested the analytical performance of a flash-type chemiluminescent immunoassay. The precision and accuracy of the assay was acceptable for early detection of sepsis and procalcitonin levels showed predictive information on the outcome of the infections. Using isolated leukocyte subpopulations and acridinium-labelled anti-calcitonin monoclonal antibody, we made attempts to detect procalcitonin inside the cells or in surrounding medium by measuring the chemiluminescent signal triggered after the specific binding of the antibodies had occurred. Our preliminary data showed that lymphocytes did not contain detectable amounts of procalcitonin nor neutrophils secreted it after stimulation. However, neutrophils expressed chemiluminescence of intracellular origin. This finding suggests that neutrophil leukocytes might be a potential source of serum procalcitonin under in vivo conditions.