Procalcitonin as a marker of systemic inflammation after conventional or minimally invasive coronary artery bypass grafting

Biomarkers of inflammation and coagulation after minimally invasive mitral valve surgery: a prospective comparison to conventional surgery

OBJECTIVES

Minimally invasive cardiac surgery techniques are increasingly used but have longer cardiopulmonary bypass time, which may increase inflammatory response and negatively affect coagulation. Our aim was to compare biomarkers of inflammation and coagulation as well as transfusion rates after minimally invasive mitral valve repair and mitral valve surgery using conventional sternotomy.

DESIGN

A prospective non-randomized study was performed enrolling 71 patients undergoing mitral valve surgery (35 right mini-thoracotomy and 36 conventional sternotomy procedures). Blood samples were collected pre- and postoperatively to assess inflammatory response. Thromboelastometry (ROTEM) was performed to assess coagulation, and transfusion rates were monitored.

RESULTS

The minimally invasive group had longer cardiopulmonary bypass times compared to the sternotomy group: 127 min ([115-146] vs 79 min [65-112], p < 0.001) and were cooled to a lower temperature during cardiopulmonary bypass, 34 °C vs 36 °C (p = 0.04). IL-6 was lower in the minimally invasive group compared to the conventional sternotomy group when measured at the end of the surgical procedure, (38 [23-69] vs 61[41-139], p = 0.008), but no differences were found at postoperative day 1 or postoperative day 3. The transfusion rate was lower in the minimally invasive group (14%) compared to full sternotomy (35%, p = 0.04) and the chest tube output was reduced, (395 ml [190-705] vs 570 ml [400-1040], p = 0.04).

CONCLUSIONS

Our data showed that despite the longer use of extra corporal circulation during surgery, minimally invasive mitral valve repair is associated with reduced inflammatory response, lower rates of transfusion, and reduced chest tube output.

Perioperative management after elective cardiac surgery: the predictive value of procalcitonin for infective and noninfective complications

Objective: Procalcitonin (PCT) has been associated with adverse outcomes after cardiac surgery. Nevertheless, there is no consensus on thresholds and timing of PCT measurement to predict adverse outcomes. Materials & methods: A total of 960 patients undergoing elective cardiac surgery were retrospectively evaluated. PCT levels were measured from the first to the seventh postoperative day (POD). The onset of complications was recorded. Results: Complications occurred in 421 (44%) patients. PCT on the third POD was associated with the occurrence of any kind of complications (odds ratio: 1.06; p: 0.037), and noninfectious complications (odds ratio: 1.05; p: 0.035), after adjusting. PCT above the median value at the third POD (>0.33 μg/l) predicted postoperative complications (incidence rate ratio: 1.13; p = 0.035). Conclusion: PCT seems to predict postoperative complications in cardiac surgery. The determination at the third POD yields the greatest sensitivity and specificity.

Procalcitonin and Conventional Markers of Inflammation in Peritoneal Dialysis Patients and Peritonitis

Objectives

To determine the significance of a newly described marker of inflammation procalcitonin (PCT), and to investigate its relationship to conventional markers of inflammation, such as C-reactive protein (CRP), fibrinogen, and erythrocyte sedimentation rate (ESR), in patients on peritoneal dialysis (PD) and with peritonitis.

Design

A prospective, observational clinical study.

Setting

The Nephrology Division of a University-affiliated teaching hospital.

Patients and Methods

51 consecutive patients on PD were included in the study. Of this number, 16 developed peritonitis during the observational period. Baseline PCT, CRP, and fibrinogen concentrations and ESR of 51 PD patients were determined at a time point (TB) prior to any evidence of infection. These results were compared with laboratory values from 74 hemodialysis patients and 34 nonuremic control subjects. All PD patients then were followed prospectively for evidence of peritonitis. In addition to routine blood tests, including hemoglobin and leukocyte count, and routine biochemical tests, blood samples were taken to measure PCT, CRP, and fibrinogen concentrations and ESR at the time (T0) when patients first were diagnosed with PD peritonitis and also on the 4th (T4) and the 14th (T14) days after treatment for peritonitis was initiated. PCT was assayed by immunoluminometry.

Results

No significant difference was observed between baseline median serum PCT concentrations in PD and hemodialysis patients; however, in both groups, baseline median PCT concentrations were significantly higher than those of nonuremic controls ( p < 0.05). The 16 patients on PD who developed peritonitis had 21 PD peritonitis episodes during the study period. The increased PCT concentration observed at T0 in PD peritonitis episodes decreased with therapy, and this change was statistically significant ( p < 0.05). In a receiver operating characteristic curve analysis for peritonitis, the area under the curve (AUC) for PCT was 0.80, which was significantly lower than the AUC for CRP and greater than the AUCs for fibrinogen and ESR. The sensitivity of PCT for peritonitis was lower than the sensitivity of conventional markers of inflammation; however, the specificity of PCT was higher.

Conclusions

Median serum PCT concentration in PD patients was significantly higher than in nonuremic controls but not hemodialysis patients. Serum PCT concentrations may serve as a useful adjunct to traditional markers of inflammation in detecting and monitoring inflammation and peritonitis in PD patients.

The role of procalcitonin and N-terminal pro-B-type natriuretic peptide in predicting outcome after cardiac surgery

OBJECTIVE(S)

Determine the thresholds of procalcitonin (PCT) and N-terminal pro-B-type natriuretic peptide (Nt-pro-BNP) associated with poor prognosis after heart surgery with CPB.

DESIGN

Prospective observational study.

SETTING

Academic Medical Center Habib Bourguiba.

PARTICIPANTS

Adult patients consecutively operated for coronary or valve surgery with CPB, elective or semi-urgent.

INTERVENTIONS

Serum concentrations of PCT and Nt-pro-BNP were determined before and after CPB, in the fourth postoperative hour (H4) and every day during the first 4 days. Receiver-operating characteristic curves and cut-off values were used to assess the ability of these markers to predict length of intensive care unit (ICU) stay >3 days.

MEASUREMENTS AND MAIN RESULTS

Forty patients were included in the study. Systemic inflammatory response syndrome (SIRS) occurred in 35 (87.5%) patients. Seventeen of them (42.5%) showed severe SIRS. Significantly higher serum concentrations of Nt-pro-BNP and PCT were found in patients with severe SIRS. Receiver operating characteristic (ROC) analysis showed that the threshold of PCT was 0.737 ng/mL and that of Nt-pro-BNP was 1235 pg/mL on day 1 could predict an ICU stay of more than 3 days. The association of Nt-pro-BNP to procalcitonin (p=0.009) better predicted the ICU stay than PCT alone (p=0.02) or Nt-pro-BNP alone (p=0.03). The best combination is Nt-pro-BNP + PCT + C-reactive protein (CRP) (p=0.007).

CONCLUSIONS

PCT and Nt-pro-BNP on day 1 may be associated with severe SIRS and predict the length of stay. A biomarker approach combining PCT, CRP and BNP is superior to a traditional single marker for predicting ICU stay.

A role for Epstein-Barr viral BALF1 in facilitating tumor formation and metastasis potential

Epstein-Barr virus (EBV) is a ubiquitous human herpesvirus that triggers transformation and tumorigenesis of latently infected B cells in vitro. BALF1, a Bcl-2-like EBV gene expressed in both latent and lytic stages, was recently characterized in EBV-infected cells; however, the role and function of BALF1 has remained elusive. Here, we demonstrate that BALF1 expression alters cellular morphology. Importantly, BALF1 promotes cellular transformation, with tumorigenicity assays showing larger and substantially greater numbers of tumors in BALF1 transfectant-injected mice compared to mice injected with pcDNA control transfectants. In addition, BALF1 expression increases cell survival under low-serum conditions, an effect that is attributable to suppression of apoptosis, not to promotion of cell-cycle progression. Furthermore, BALF1 transfectants exhibit markedly increased tumor metastasis in vitro and in vivo. Taken together, these findings suggest that BALF1 may be a new tumor marker for EBV diagnosis and provide a new direction for research on treatments of EBV-associated tumors.

A Transapical or Transluminal Approach to Aortic Valve Implantation Does Not Attenuate the Inflammatory Response

Background: Cardiopulmonary bypass (CPB) and cardiac surgery cause an inflammatory response, as measurable by an increase in the concentration of C-reactive protein (CRP), a nonspecific inflammation marker. Previous publications have demonstrated typical perioperative CRP concentration profiles in cases of uncomplicated aortic valve replacement (AVR) with CPB. A regression analysis for modifying factors showed that chronic disease (heart failure, diabetes, and pulmonary disease), along with obesity and sex, all tend to influence the CRP response. We analyzed the inflammatory response to aortic valve implantation (AVI) with interventional techniques, mainly transapical but also transfemoral and transaxillary approaches, in a retrospective case-control study design.Methods: Sixty-eight patients who underwent AVI by the transapical (59 patients), transfemoral (7 patients), or transaxillary (2 patients) approach were matched by age, sex, body mass index (BMI), and chronic-disease state (absence or presence of diabetes, pulmonary disease, and renal impairment) with 68 patients who underwent conventional AVR with CPB. We compared the 2 groups with respect to perioperative CRP concentration, EuroSCORE, and outcome data (time to extubation and 30-day mortality). All data were collected prospectively and analyzed retrospectively.Results: The 2 groupsthe study population (interventional) and the control population (conventional)were similar in age, sex distribution, BMI, and chronic-disease status. As expected, the study population had a significantly higher median EuroSCORE. The 2 groups had similar postoperative CRP profiles over time, but the interventional group had significantly higher peak concentrations on days 2, 3, and 4. The short-term outcomes, as assessed by ventilation time and 30-day mortality, were similar for the 2 groups.Conclusions: Using an interventional transcatheter approach to AVI (thereby eliminating CPB from the procedure and reducing surgical trauma) does not attenuate the patient's innate inflammatory response.

Procalcitonin in patients undergoing cardiopulmonary bypass in open heart surgery-first results of the Procalcitonin in Heart Surgery study (ProHearts)

OBJECTIVE

To investigate procalcitonin (PCT) levels in patients undergoing cardiopulmonary bypass (CPB) in order to assess the prevalence and prognostic capacity of elevated PCT levels following CPB in open heart surgery.

DESIGN

prospective observational study in consecutive patients.

SETTING

Twenty-four-bed ICU, department of thoracic and cardiovascular surgery, university hospital.

PATIENTS

Seven hundred and twenty two patients, 691 of whom underwent CPB, i.e., 476 had coronary bypass surgery (CABG), 130 valve replacement, 34 combined CABG and valve replacement and 23 thoracic aortic surgery.

INTERVENTIONS

Standard perfusion techniques were used with cardioplegic arrest and mild hypothermia (28-32 degrees C). With the exception of thoracic aortic procedures, full-flow perfusion was performed.

MEASUREMENTS AND RESULTS

PCT was measured prior to surgery and daily thereafter until ICU discharge or death. PCT significantly increased at day 1 postoperatively compared to baseline values (0.25+/-1.65 vs 6.49+/-22.0 ng/ml, p<0.005). However, in 55.1% of patients PCT was below 1.0 ng/ml. In 12.8% of CABG patients PCT was increased to >5.0 ng/ml, compared to 39% in valve patients and 35% of patients with aortic surgery. An elevated PCT level >1.0-5.0 ng/ml at day 1 was highly predictive of mortality (P<0.03, vs<1.0 ng/ml), with an additional accuracy when levels >5.0 ng/ml were measured (P<0.002 vs<1.0 ng/ml).

CONCLUSIONS

These results provide evidence that PCT might serve as an early prognostic marker in patients undergoing CPB in open heart surgery. It may be worth considering immunomodulating approaches in patients presenting elevated PCT levels in the early phase after CPB.

Secretory phospholipase A2 activity and release kinetics of vascular tissue remodelling biomarkers after coronary artery bypass grafting with and without cardiopulmonary bypass

BACKGROUND

Cardiopulmonary bypass (CPB) has long been recognised as a main cause of a postoperative complex systemic inflammatory response after coronary artery bypass grafting (CABG).

METHODS

We determined the kinetics of peripheral blood release of the novel inflammatory biomarkers secretory phospholipase A(2) (sPLA(2)), matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) during the first 6 days following surgery in 16 patients undergoing CABG with (on-pump, n=9) or without (off-pump, n=7) CPB. Kinetic curves for these markers were compared to those of the well-known inflammatory parameters C-reactive protein (CRP) and fibrinogen.

RESULTS

sPLA(2) activity exhibited a maximum value on day 2, then decreased until day 6 for both groups and in a similar manner as CRP levels. On the other hand, elevation of plasma levels of both MMP-9 and TIMP-1 occurred as early as on day 1 and remained at this level until day 6. No significant difference in kinetic characteristics (peak value, area under the curve, initial slope) between CABG with and without CPB was observed.

CONCLUSIONS

These data show that the off- and on-pump groups did not show significantly different kinetics for the releases of all biomarkers studied, including sPLA(2) and biomarkers of the MMP-TIMP network. The off-pump procedure may therefore lead to global surgical trauma as important as CPB in terms of the systemic inflammatory process and matrix proteolysis pathway activation.

Modulation of systemic inflammatory response after cardiac surgery

Cardiac surgery and cardiopulmonary bypass initiate a systemic inflammatory response largely determined by blood contact with foreign surfaces and the activation of complement. It is generally accepted that cardiopulmonary bypass initiates a whole-body inflammatory reaction. The magnitude of this inflammatory reaction varies, but the persistence of any degree of inflammation may be considered potentially harmful to the cardiac patient. The development of strategies to control the inflammatory response following cardiac surgery is currently the focus of considerable research efforts. Diverse techniques including maintenance of hemodynamic stability, minimization of exposure to cardiopulmonary bypass circuitry, and pharmacologic and immunomodulatory agents have been examined in clinical studies. This article briefly reviews the current concepts of the systemic inflammatory response following cardiac surgery, and the various therapeutic strategies being used to modulate this response.

Quantitative analysis of procalcitonin after pediatric cardiothoracic surgery

Procalcitonin appears to be an early and sensitive marker of bacterial infection in a variety of clinical settings. The use of levels of procalcitonin to predict infection in children undergoing cardiac surgery, however, may be complicated by the systemic inflammatory response that normally accompanies cardiopulmonary bypass. The aim of our study was to estimate peri-operative concentrations of procalcitonin in non-infected children undergoing cardiac surgery. Samples of serum for assay of procalcitonin were obtained in 53 patients at baseline, 24, 48, and 72 hours following cardiac surgery. Concentrations were assessed using an immunoluminetric technique. Median concentrations were lowest at baseline at less than 0.5 nanograms per millilitre, increased at 24 hours to 1.8 nanograms per millilitre, maximized at 48 hours at 2.1 nanograms per millilitre, and decreased at 72 hours to 1.3 nanograms per millilitre, but did not return to baseline levels. Ratios of concentrations between 24, 48 and 72 hours after surgery as compared to baseline were 6.15, with 95 percent confidence intervals between 4.60 and 8.23, 6.49, with 95 percent confidence intervals from 4.55 to 9.27, and 4.26, with 95 percent confidence intervals between 2.78 and 6.51, respectively, with a p value less than 0.001. In 8 patients, who had no evidence of infection, concentrations during the period from 24 to 72 hours were well above the median for the group. We conclude that concentrations of procalcitonin in the serum increase significantly in children following cardiac surgery, with a peak at 48 hours, and do not return to baseline within 72 hours of surgery. A proportion of patients, in the absence of infection, had exaggerated elevations post-operatively.

Diagnostic value and prognostic implications of serum procalcitonin after cardiac surgery: a systematic review of the literature

INTRODUCTION

Systemic inflammatory response syndrome is common after surgery, and it can be difficult to discriminate between infection and inflammation. We performed a review of the literature with the aims of describing the evolution of serum procalcitonin (PCT) levels after uncomplicated cardiac surgery, characterising the role of PCT as a tool in discriminating infection, identifying the relation between PCT, organ failure, and severity of sepsis syndromes, and assessing the possible role of PCT in detection of postoperative complications and mortality.

METHODS

We performed a search on MEDLINE using the keyword 'procalcitonin' crossed with 'cardiac surgery,' 'heart,' 'postoperative,' and 'transplantation.' Our search was limited to human studies published between January 1990 and June 2006.

RESULTS

Uncomplicated cardiac surgery induces a postoperative increase in serum PCT levels. Peak PCT levels are reached within 24 hours postoperatively and return to normal levels within the first week. This increase seems to be dependent on the surgical procedure and on intraoperative events. Although PCT values reported in infected patients are generally higher than in non-infected patients after cardiac surgery, the cutoff point for discriminating infection ranges from 1 to 5 ng/ml, and the dynamics of PCT levels over time may be more important than absolute values. PCT is superior to C-reactive protein in discriminating infections in this setting. PCT levels are higher with increased severity of sepsis and the presence of organ dysfunction/failure and in patients with a poor outcome or in those who develop postoperative complications. PCT levels typically remain unchanged after acute rejection but increase markedly after bacterial and fungal infections. Systemic infections are associated with greater PCT elevation than is local infection. Viral infections are difficult to identify based on PCT measurements.

CONCLUSION

The dynamics of PCT levels, rather than absolute values, could be important in identifying patients with infectious complications after cardiac surgery. PCT is useful in differentiating acute graft rejection after heart and/or lung transplantation from bacterial and fungal infections. Further studies are needed to define cutoff points and to incorporate PCT levels in useful prediction models.

High concentrations of N-BNP are related to non-infectious severe SIRS associated with cardiovascular dysfunction occurring after off-pump coronary artery surgery †

BACKGROUND

Procalcitonin (PCT) blood concentrations are known to be an appropriate marker of severe systemic inflammatory response syndrome (SIRS) induced by coronary artery surgery with and without cardiopulmonary bypass. Pro-brain natriuretic peptide (N-BNP) is a newly described cardiac hormone considered to be an effective marker of severity and prognosis of acute coronary syndromes and congestive heart failure. We evaluated the perioperative time courses of PCT and N-BNP and investigated their role as early markers of severe SIRS (SIRS with cardiovascular dysfunction) induced by off-pump coronary artery bypass (OPCAB).

METHODS

Sixty-three patients were prospectively included. The American College of Chest Physicians Classification was used to diagnose SIRS and organ system failure to define severe SIRS. Serum concentrations of PCT and N-BNP were determined before, during and after surgery. Receiver operating characteristic curves and cut-off values were used to assess the ability of these markers to predict postoperative severe SIRS.

RESULTS

SIRS occurred in 25 (39%) patients. Nine of them (14%) showed severe SIRS. Significantly higher serum concentrations of N-BNP and PCT were found in patients with severe SIRS with peak concentrations respectively at 8887 pg ml(-1) (range 2940-29372 pg ml(-1)) for N-BNP and 9.50 ng ml(-1) (range 1-65 ng ml(-1)) for PCT. The area under the curve using N-BNP to detect postoperative severe SIRS was 0.799 before surgery (0.408 for PCT; P<0.01) and 0.824 at the end of surgery (0.762 for PCT; P<0.05).

CONCLUSIONS

N-BNP may be an appropriate marker indicating the early development of non-infectious postoperative severe SIRS after OPCAB.

Procalcitonin and C-reactive protein kinetics in postoperative pediatric cardiac surgical patients

OBJECTIVE

To determine the kinetics of procalcitonin (PCT) and C-reactive protein (CRP) concentration after pediatric cardiac surgery with cardiopulmonary bypass.

DESIGN

Prospective, clinical cohort study.

SETTING

A fifteen-bed tertiary-care pediatric intensive care unit.

PATIENTS

Fourteen pediatric patients admitted for cardiac surgery.

MEASUREMENTS AND MAIN RESULTS

Serum PCT and CRP were measured before cardiopulmonary bypass (CPB); after CPB; and on the first, second, and third days after surgery by means of immunoluminometry and nephelometry, respectively. Reference values for systemic inflammatory response syndrome are 0.5 to 2.0 ng/mL for PCT and <5 mg/L for CRP. Baseline serum PCT and CRP concentrations were 0.24 +/- 0.13 ng/mL and 4.06 +/- 3.60 mg/L (median 25th percentile-75th percentile), respectively. PCT concentrations increased progressively from the end of CPB (0.62 +/- 0.30 ng/mL), peaked at 24 hours postoperatively (POD1) (0.77 +/- 0.49 ng/mL), and began to decrease at 48 hours or POD2 (0.35 +/- 0.21 ng/mL). CRP increased just after CPB (58.82 +/- 42.23 mg/L) and decreased after 72 hours (7.09 +/- 9.81 mg/L).

CONCLUSION

An increment of both PCT and CRP was observed just after CPB. However, PCT values remained within reference values, whereas CRP concentrations increased significantly after CPB until the third day. These preliminary results suggest that PCT was more effective than CRP to monitor patients with SIRS and a favorable outcome.

Hepatic ischemia-reperfusion syndrome after partial liver resection (LR): hepatic venous oxygen saturation, enzyme pattern, reduced and oxidized glutathione, procalcitonin and interleukin-6

The hepatic ischemia-reperfusion syndrome was investigated in 28 patients undergoing elective partial liver resection with intraoperative occlusion of hepatic inflow (Pringle maneuver) using the technique of liver vein catheterization. Hepatic venous oxygen saturation (ShvO2) was monitored continuously up to 24 hours after surgery. Aspartate aminotransferase, glutamate dehydrogenase, gamma-glutamyl transpeptidase, pseudocholinesterase, alpha-glutathione S-transferase, reduced and oxidized glutathione, procalcitonine, and interleukin-6 were serially measured both before and after Pringle maneuver during the resection and postoperatively in arterial and/or hepatic venous blood. ShvO2 measurement demonstrated that peri- and postoperative management was suitable to maintain an optimal hepatic oxygen supply. As expected, we were able to demonstrate a typical enzyme pattern of postischemic liver injury. There was a distinct decrease of reduced glutathione levels both in arterial and hepatic venous plasma after LR accompanied by a strong increase in oxidized glutathione concentration during the phase of reperfusion. We observed increases in procalcitonin and interleukin-6 levels both in arterial and hepatic venous blood after declamping. Our data support the view that liver resection in man under conditions of inflow occlusion resulted in ischemic lesion of the liver (loss of glutathione synthesizing capacity with disturbance of protection against oxidative stress) and an additional impairment during reperfusion (liberation of reactive oxygen species, local and systemic inflammation reaction with cytokine production). Additionally, we found some evidence for the assumption that the liver has an export function for reduced glutathione into plasma in man.

Kinetics of procalcitonin, interleukin 6 and C-reactive protein after cardiopulmonary-bypass in children

Cardiopulmonary bypass induces a generalized inflammatory response, with fever and leukocytes, which is difficult to differentiate from an infection. Recently, procalcitonin has been proposed as an early and specific marker of bacterial infection. The influence of cardiopulmonary bypass on production of procalcitonin, therefore, must be assessed before considering this molecule as a valuable marker of infection after cardiac surgery in children. With this in mind, we measured levels of procalcitonin, interleukin 6, and C-reactive protein before and 6h, 1, 3 and 5 days after cardiopulmonary bypass, in 25 children undergoing cardiac surgery. Cardiopulmonary-bypass induced a transient increase in procalcitonin, with a peak at 24 h, with a median of 1.13 microg/l, a 25th and 75th interquartile of 0.68-2.25, and a p value of less than 0.001. The value had returned to normal in the majority of the children by the third day after surgery. Peak values correlated with the duration of cardiopulmonary-bypass, with a r-value of 0.58 and a p value of 0.003; cross-clamp time, with a r-value of 0.62 and a p value of 0.001; days of mechanical ventilation, with a r-value of 0.62 and a p value of 0.001; and days of stay in intensive care, with a r-value of 0.68, and a p value of 0.0003. The value returned to normal after 3 days in 83% of the patients. Levels of interleukin 6 and C-reactive protein also increased significantly after surgery, and remained elevated for up to 5 days. Thus, in contrast to other markers, levels of procalcitonin in the serum are only slightly and transiently influenced by cardiopulmonary bypass, and may prove to be useful in the early recognition of an infection subsequent to cardiopulmonary bypass.

Modulation of the inflammatory response to cardiopulmonary bypass by dopexamine and epidural anesthesia

BACKGROUND

Cardiopulmonary bypass (CPB) induces a systemic inflammatory reaction. Microcirculation-dependent alteration of the gut mucosal barrier with subsequent translocation of endotoxins is a postulated mechanism for this inflammatory response. This study was designed to elucidate whether two different approaches to modulate splanchnic perfusion may influence systemic inflammation to CPB.

METHODS

We examined 40 patients scheduled for elective coronary bypass surgery in a prospective, randomized study. One group (DPX) received dopexamine (1 micro g. kg-1. min-1) continuously after induction of anesthesia until 18 h after CPB. The control group (CON) received equal volumes of NaCl 0.9% in a time-matched fashion. In a third group (EPI) a continuous epidural infusion of bupivacaine 0.25% [(body height (cm) - 100). 10-1=ml.h-1] was administered for the whole study period. Procalcitonin (PCT), tumor necrosis factor (TNF-alpha), soluble TNF receptor, human soluble intercellular adhesion molecule-1, C-reactive protein (CRP) and leukocyte count were measured as parameters of inflammation.

RESULTS

All parameters significantly increased following CPB. Increases of PCT, TNF-alpha and leukocyte count were significantly attenuated in the DPX and EPI groups at different time points. However, neither splanchnic blood flow nor oxygen delivery and consumption were different when compared with the CON-group.

CONCLUSION

These results do suggest that mechanisms other than an improved splanchnic blood flow by DPX and EPI treatment have to be considered for the anti-inflammatory effects.

Common promoter variant in cyclooxygenase-2 represses gene expression: evidence of role in acute-phase inflammatory response

OBJECTIVE

Cyclooxygenase (COX)-2 is a key regulatory enzyme in the synthesis of prostanoids associated with trauma and inflammation. We investigated the COX-2 gene for functional variants that may influence susceptibility to disease.

METHODS AND RESULTS

The promoter of COX-2 was screened for variants in healthy subjects by use of polymerase chain reaction-based methods. Promoter activity was investigated by using reporter expression experiments in human lung fibroblasts. Patients undergoing coronary artery bypass graft surgery, with measurements of plasma markers linked to COX-2 activity, were genotyped for association studies. A common COX-2 promoter variant, -765G>C, was found and shown to be carried by >25% of a group of healthy UK subjects. The -765C allele had significantly lower promoter activity compared with -765G, basally (28+/-3% lower, P<0.005) and in serum-stimulated cells (31+/-2% lower, P<0.005). In patients subjected to coronary artery bypass graft surgery, the magnitude of rise in levels of C-reactive protein (CRP) was strongly genotype dependent. Compared with -765G homozygotes, patients carrying the -765C allele had significantly lower plasma CRP levels at 1 to 4 days after surgery (14% lower at the peak of CRP levels on day 3, P<0.05 for all time points).

CONCLUSIONS

For several acute and chronic inflammatory diseases, -765G>C may influence the variability of response observed.

Procalcitonin and neopterin as indicators of infection in critically ill patients

BACKGROUND

: In critically ill patients, severe infection and systemic inflammation due to non-infectious causes produce very similar clinical presentations, and traditional infection markers do not always differentiate these two conditions. Both procalcitonin and neopterin have been suggested to aid in the early diagnosis of bacterial infections and in differentiating bacterial infections from systemic inflammatory, non-infectious diseases or from viral infections.

METHODS

: Procalcitonin (PCT) and neopterin were analyzed in 208 ICU patients who developed acute fever or septic shock. Blood samples were taken every 8th h within 48 h of the onset of fever or septic shock.

RESULTS

: A total 162/208 of patients had infection, the most common location being the respiratory tract. Mortality was higher in infected patients (31.4% vs. 10.9%; P < 0.01). The optimum cut-off levels in identifying patients with infection of daily peak PCT were 0.8 microg/L on day 1 and 0.9 microg/L on day 2, and both sensitivity (67.7% and 60.9%, respectively) and specificity (47.8% and 63%) were poor. Accordingly, the optimum cut-off values of peak neopterin were 18 and 16 pg/L. The sensitivity was 62.7% on day 1 and 69.3% on day 2, while specificity was correspondingly 78.3% and 67.9%. There were no significant differences between the markers in discriminating between patients with infection or inflammation. Both PCT and neopterin increased with the severity of infection. They were higher in non-survivors.

CONCLUSION

: PCT and neopterin were equally effective, although not very accurate in differentiating between infection and inflammation in critically ill patients. Neopterin was more specific than PCT, suggesting that neopterin is related to the activity of inflammatory response.

Pulmonary dysfunction after cardiac surgery

Postoperative lung injury is one of the most frequent complications of cardiac surgery that impacts significantly on health-care expenditures and largely has been believed to result from the use of cardiopulmonary bypass (CPB). However, recent comparative studies between conventional and off-pump coronary artery bypass grafting have indicated that CPB itself may not be the major contributor to the development of postoperative pulmonary dysfunction. In our study, we review the associated physiologic, biochemical, and histologic changes, with particular reference to the current understanding of underlying mechanisms. Intraoperative modifications aiming at limiting lung injury are discussed. The potential benefits of maintaining ventilation and pulmonary artery perfusion during CPB warrant further investigation.

Procalcitonin following elective partial liver resection--origin from the liver?

BACKGROUND

The origin of the inflammatory peptide procalcitonin (PCT) is still unknown. In the present study PCT concentrations in arterial and hepatic-venous blood were examined in patients undergoing elective partial liver resection (LR) using a fiberoptic pulmonary arterial catheter placed in a liver vein to obtain further information on the origin of PCT.

METHODS

In 28 patients (21 male/7 female; average age of 58.8+/-8.8 years) undergoing LR, arterial and hepatic venous PCT concentrations were measured during 24 h perioperatively. The parallel blood withdrawals occurred immediately before the Pringle maneuver (Hx), 2 min, 1, 2, 6, 12, and 24 h after Hx. Over the whole period, the oxygen saturation in hepatic venous blood (ShvO2) was monitored. PCT concentrations were assayed by immunoluminometry.

RESULTS

We observed a significant increase in PCT concentration already 6 h after Hx compared to the values before Hx. Twenty-four hours after Hx we found the highest plasma concentrations. It was conspicuous that hepatic venous PCT concentrations were always higher than the arterial ones (significantly from the 6th hour after Hx). There was no correlation between the courses of ShvO2 and PCT rise. A significant correlation was verified between Hx duration and PCT concentration measured 24 h after Hx both in the hepatic venous and arterial blood.

CONCLUSIONS

The results of our investigation can be interpreted as evidence that liver (or the hepatosplanchnicus?) is a source of PCT. The mechanism of PCT induction cannot be clarified by our study: whether the induction of PCT was caused by an endotoxin translocation during the impeded splanchnic outflow or by the direct surgery-induced lesion (hypoxia) of the liver remains unclear. However, the latter appears more probable because of the observed correlation between Hx duration and PCT concentration rise.

Systemic inflammation and cardiac surgery: an update

Cardiac surgery with cardiopulmonary bypass (CPB) is associated with the development of a systemic inflammatory response that can often lead to dysfunction of major organs. The systemic inflammation can be assessed intra- and postoperatively by measuring concentrations of inflammatory mediators in plasma and tissues. These concentrations, however, do not always correlate with the degree of observed organ dysfunction. Various strategies have been used to reduce inflammatory phenomena in patients undergoing CPB. Cardiac surgery without CPB has been performed increasingly with satisfactory results over the past few years. Attenuation of systemic inflammation and improved outcome in high risk patients are potential benefits of this technique. The emergence and expanding performance of cardiac surgical procedures without the use of CPB has given us an excellent tool to investigate the relative importance of CPB as a cause of systemic inflammation. Aprotinin is a protease inhibitor which is used in cardiac surgical patients for its haemostatic effects. Aprotinin has anti-inflammatory properties, the nature of which have not been completely clarified. This article presents a summary of the published literature investigating inflammatory response and organ dysfunction in patients who have cardiac surgery without CPB. It also presents an overview of recent data on the anti-inflammatory action mechanisms of aprotinin.

Plasma levels of procalcitonin and interleukin-6 in acute myocardial infarction

Estimation of cardiac morbidity in patients after major surgery is a difficult problem. In addition, infectious complications seriously decrease potential beneficial outcome after cardiovascular surgery. The present study assessed the use of a newer marker of the inflammatory response, procalcitonin, in the field of myocardial infarction, in conjunction with measurements of interleukin-6. Forty-four consecutive cases with acute myocardial infarction were included in the study 4+/-1.3 h after the onset of symptoms. Plasma levels of procalcitonin and interleukin-6 were obtained at admission, and after 3, 6, 12, 18, 24 and 48 h, using commercially available test kits. The range of levels of interleukin-6 and procalcitonin was about normal at admission. Interleukin-6 levels increased significantly following myocardial infarction, whereas procalcitonin were essentially unchanged, i.e. remained close to the normal level threshold of 0.5 ng/ml; only minor variability occurred with a mean peak level of procalcitonin of 1+/-0.4 ng/ml. Data demonstrate that, in contrast to the acute phase reactant interleukin-6, plasma levels procalcitonin are not significantly elevated during uncomplicated acute myocardial infarction. This observation may support the role of procalcitonin measurements in the differential diagnosis of infectious and cardiovascular complications after major surgery.

Hyperprocalcitonemia in patients with perioperative myocardial infarction after cardiac surgery

OBJECTIVE

To describe and compare procalcitonin (PCT) concentrations after cardiac surgery in uncomplicated patients and in patients with perioperative myocardial infarction (PMI).

DESIGN

Retrospective comparative study.

SETTING

One university hospital.

PATIENTS

Fifty-eight adult patients undergoing cardiac surgery.

INTERVENTION

None.

MEASUREMENTS AND MAIN RESULTS

In a first step, plasma PCT and C-reactive protein concentrations were measured preoperatively and until 72 hrs postoperatively in ten consecutive patients who underwent uncomplicated cardiac surgery. PCT concentrations increased progressively from the end of cardiopulmonary bypass (0.09 +/- 0.09 ng/mL), peaked at 24 hrs postoperatively (1.14 +/- 1.24 ng/mL), and began to decrease at 48 hrs. C-reactive protein appeared to peak at 48 hrs (from 5.8 +/- 11.7 mg/L preoperatively to 265.1 +/- 103.5 mg/L on the second postoperative day). In a second step, PCT concentrations were measured at day one in 23 patients (PMI group) who presented high postoperative plasma cardiac troponin I concentrations and were compared with PCT concentrations observed in 25 matched uncomplicated patients. All patients were free from infection. PCT in the PMI group was significantly higher than in the control group (27.1 +/- 63.2 vs. 2.0 +/- 2.4 ng/mL, respectively; p =.0053).

CONCLUSION

Because high plasma concentrations of PCT were found in patients with PMI after cardiac surgery, it may be suggested that, in the early postoperative period, elevated plasma PCT concentrations should be interpreted with caution regarding infection diagnosis.

High-dose aprotinin modulates the balance between proinflammatory and anti-inflammatory responses during coronary artery bypass graft surgery

OBJECTIVE

To rule out the effect of high-dose aprotinin in respect to the balance of proinflammatory and anti-inflammatory mediators induced by cardiopulmonary bypass (CPB).

DESIGN

Randomized, double-blind, placebo-controlled study.

SETTING

University-affiliated cardiac center.

PARTICIPANTS

Twenty patients scheduled for coronary artery bypass graft surgery.

INTERVENTIONS

In group A patients (n = 10), high-dose aprotinin was administered (2 x 106 KIU pre-CPB, 2 x 10(6) KIU in prime, 500,000 KIU/hr during CPB). In group C patients (n = 10), placebo was used instead. Proinflammatory interleukin (IL)-6, anti-inflammatory IL-1-receptor antagonist, and clinical parameters were measured 8 times perioperatively. The values are presented as mean +/- SEM.

MEASUREMENTS AND MAIN RESULTS

Four hours after CPB, IL-6 concentration reached the maximum value, being significantly lower in group A patients as compared with group C patients (615 +/- 62 pg/mL v 1,409 +/- 253 pg/mL; p = 0.019). On the first postoperative day, the concentration of IL-6 in group A patients remained lower (219 +/- 24 pg/mL v 526 +/- 123 pg/mL; p = 0.015). In contrast, IL-1-receptor antagonist concentration was higher in group A patients as compared with group C patients after CPB (13,857 +/- 4,264 pg/mL v 5,675 +/- 1,832 pg/mL; p = 0.03). Total postoperative blood loss was lower in group A patients as compared with group C patients (648 +/- 64 mL v 1,284 +/- 183 mL; p = 0.002).

CONCLUSIONS

High-dose aprotinin treatment reduced the inflammatory reaction and postoperative blood loss. The anti-inflammatory reaction was significantly enhanced in these patients, which suggests that the physiologic reaction of the organism to reduce the deleterious effects from CPB is more pronounced by using high-dose aprotinin.

Usefulness of procalcitonin for diagnosis of infection in cardiac surgical patients

OBJECTIVE

To determine the value of procalcitonin (PCT) as a marker of postoperative infection after cardiac surgery.

DESIGN

A prospective single institution three phase study.

SETTING

University cardiac surgical intensive care unit (31 beds).

PATIENTS

Phase 1: To determine the normal perioperative kinetics of PCT, 20 consecutive patients undergoing elective cardiac surgery with cardiopulmonary bypass were included. Phase 2: To determine whether PCT may be useful for diagnosis of postoperative infection, 97 consecutive patients with suspected infection were included. Phase 3: To determine the ability of PCT to differentiate patients with septic shock from those with cardiogenic shock, 26 patients with postoperative circulatory failure were compared.

MEASUREMENTS AND MAIN RESULTS

Phase 1: Serum samples were drawn for PCT determination after induction of anesthesia (baseline), at the end of surgery, and daily until postoperative day (POD) 8. Baseline serum PCT concentration was 0.17 +/- 0.08 ng/mL (mean +/- SD). Serum PCT increased after cardiac surgery with a peak on POD 1 (1.08 +/- 1.36). Serum PCT returned to normal range on POD 3 and remained stable thereafter. Phase 2: In patients with suspected infection, serum PCT was measured at the same time of C-reactive protein (CRP) and bacteriologic samples. Among the 97 included patients, 54 were infected with pneumonia (n = 17), bacteremia (n = 16), mediastinitis (n = 9), or septic shock (n = 12). In the 43 remaining patients, infection was excluded by microbiological examinations. In noninfected patients, serum PCT concentration was 0.41 +/- 0.36 ng/mL (range, 0.08-1.67 ng/mL). Serum PCT concentration was markedly higher in patients with septic shock (96.98 +/- 119.61 ng/mL). Moderate increase in serum PCT concentration occurred during pneumonia (4.85 +/-3.31 ng/mL) and bacteremia (3.57 +/- 2.98 ng/mL). Serum PCT concentration remained low during mediastinitis (0.80 +/- 0.58 ng/mL). Five patients with mediastinitis, two patients with bacteremia, and one patient with pneumonia had serum PCT concentrations of <1 ng/mL. These eight patients were administered antibiotics previously and serum PCT was measured during a therapeutic antibiotic window. For prediction of infection by PCT, the best cutoff value was 1 ng/mL, with sensitivity 85%, specificity 95%, positive predictive value 96%, and negative predictive value 84%. Serum CRP was high in all patients without intergroup difference. For prediction of infection by CRP, a value of 50 mg/L was sensitive (84%) but poorly specific (40%). Comparing the area under the receiver operating characteristic curves, PCT was better than CRP for diagnosis of postoperative sepsis (0.82 for PCT vs. 0.68 for CRP). Phase 3: Serum PCT concentration was significantly higher in patients with septic shock than in those with cardiogenic shock (96.98 +/- 119.61 ng/mL vs. 11.30 +/- 12.3 ng/mL). For discrimination between septic and cardiogenic shock, the best cutoff value was 10 ng/mL, with sensitivity of 100% and specificity of 62%.

CONCLUSION

Cardiac surgery with cardiopulmonary bypass influences serum PCT concentration with a peak on POD 1. In the presence of fever, PCT is a reliable marker for diagnosis of infection after cardiac surgery, except in patients who previously received antibiotics. PCT was more relevant than CRP for diagnosis of postoperative infection. During a postoperative circulatory failure, a serum PCT concentration >10 ng/mL is highly indicative of a septic shock.