Usefulness of procalcitonin for diagnosis of infection in cardiac surgical patients

Interleukin-6 as a critical inflammatory marker for early diagnosis of surgical site infection after spine surgery

PURPOSE

Early diagnosis of surgical site infections (SSIs) could prevent surgical revision. Inflammatory markers (IMs), such as procalcitonin (PCT), interleukin-6 (IL-6), and tumor necrosis factor α (TNF-α), seem more accurate in diagnosing SSI than C-reactive protein (CRP) and white blood cell (WBC) count. The aim was to compare the predictive values of CRP, WBC count, PCT, IL-6, and TNF-α in SSI detection.

METHODS

A total of 130 patients undergoing dorsal spondylodesis from 2019 to 2024 were enrolled in a prospective diagnostic study at a maximum care spine center. IMs were measured preoperatively and on the postoperative days (PODs) 1, 2, 3, 5, and 7. Patients with high suspicion of SSI underwent revision surgery. SSI was diagnosed when the microbiological evidence was positive. Patients were divided a posteriori into the non-infection and infection groups.

RESULTS

IMs of 118 patients (66.9 ± 13.0 years, 61.0% females) were measured. Fifteen of the 118 patients (12.7%) developed an SSI. The groups differed with respect to existing hypertension, number of instrumented segments, region of surgery, CRPPOD1,7, PCTPOD7, and IL-6POD3,5,7. Binary logistic regression for SSI detection including these parameters showed an area under the curve (AUC) of 0.88 (95% CI 0.79-0.98; P < 0.001). The main effect for SSI detection was maintained by IL-6POD7 (odds ratio = 1.13; 95% CI 1.05-1.23; P = 0.001), which itself showed an AUC of 0.86 (95% CI 0.75-0.97).

CONCLUSION

Compared to CRP, WBC count, PCT, and TNF-α, IL-6 seems to be the critical IM for the early detection of an SSI.

TRIAL REGISTRATION

drks.de: DRKS00033773, date of registration: 29.02.2024, retrospectively registered; Postoperative Markers of Inflammation in Spine Surgery (POMIS) Trial.

Early predictors of bacterial pneumonia infection in children with congenital heart disease after cardiopulmonary bypass: a single-centre retrospective study

OBJECTIVES

The objective of this study was to evaluate the early predictors of bacterial pneumonia infection in children with congenital heart disease (CHD) after cardiopulmonary bypass (CPB).

DESIGN

Retrospective study.

SETTING

A freestanding tertiary paediatric hospital in China.

PARTICIPANTS

Patients admitted to the hospital due to CHD who underwent open-heart surgery.

OUTCOME MEASURES

We retrospectively reviewed and analysed data from 1622 patients with CHD after CPB from June 2018 to December 2020 at the Children's Hospital of Nanjing Medical University. Enrolled patients were assigned to an infection group or a non-infection group according to the presence of postoperative bacterial pneumonia infection, and the differences in clinical indicators were compared. Potential predictors were analysed by multivariate logistic regression analysis and area under the curve (AUC) analysis.

RESULTS

Among the 376 patients (23.2%) in the infection group, the three most common bacteria were Streptococcus pneumoniae in 67 patients (17.8%), Escherichia coli in 63 patients (16.8%) and Haemophilus influenzae in 53 patients (14.1%). The infection group exhibited a lower weight (8.0 (6.0-11.5) kg vs 11.0 (7.5-14.5) kg, p<0.001). In the infection group, procalcitonin (PCT) (ng/mL: 4.72 (1.38-9.52) vs 1.28 (0.47-3.74), p<0.001) and C reactive protein (CRP) (mg/L: 21.0 (12.1-32.0) vs 17.0 (10.0-27.0), p<0.001) levels were significantly greater than those in the non-infection group. Binary logistic regression analysis revealed that weight, PCT and CRP were independent risk factors for pulmonary bacterial infection after CPB. The AUCs of weight, PCT, CRP and PCT+CRP for predicting pulmonary bacterial infection after CPB were 0.632 (95% CI 0.600 to 0.664), 0.697 (95% CI 0.667 to 0.727), 0.586 (95% CI 0.554 to 0.618) and 0.694 (95% CI 0.664 to 0.724), respectively, and the cut-off values were ≤10.25 kg, ≥4.25 ng/mL, ≥6.50 mg/L and ≥0.20, respectively. The sensitivities were 69.7%, 54.0%, 93.9% and 70.2%, and the specificities were 53.5%, 77.7%, 19.4% and 59.1%, respectively.

CONCLUSIONS

In our study, weight, PCT and CRP were found to be independent predictors of pulmonary bacterial infection after CPB. Moreover, PCT was the most specific predictor, and CRP was the most sensitive independent predictor that might be beneficial for the early diagnosis of pulmonary bacterial infection after CPB in patients with CHD.

Predictive value of perioperative procalcitonin, C reactive protein and high-sensitivity C reactive protein for the risk of postoperative complications after non-cardiac surgery in elderly patients: a nested case-control study

OBJECTIVE

Little is known about the correlation between perioperative concentrations of inflammatory biomarkers and postoperative complications. This study explored whether the plasma concentrations and perioperative changes of procalcitonin (PCT), C reactive protein (CRP) and high-sensitivity CRP (hsCRP) could predict the risk of postoperative morbidity in elderly patients undergoing elective non-cardiac surgery.

DESIGN

A nested case-control study.

SETTING

A tertiary hospital in China.

PARTICIPANTS

A total of 498 patients aged ≥65 years from a prospective cohort who underwent elective non-cardiac surgery between June 2020 and April 2021.

PRIMARY OUTCOME MEASURES

The primary outcomes were the efficacy of plasma concentrations of PCT, CRP and hsCRP in predicting the risk of Clavien-Dindo Classification (CDC) ≥grade 3 and major complications. The major complications included mortality, an intensive care unit stay length >24 hour, cardiovascular events, acute kidney injury, postoperative cognitive dysfunction and infections.

RESULTS

For major complications, the area under the curve (AUC) (95% CI) of PCT-24 hours, PCT change and PCT change rate were 0.750 (0.698 to 0.803), 0.740 (0.686 to 0.795) and 0.711 (0.651 to 0.771), respectively. The AUC (95% CI) of CRP-24 hours, CRP change, CRP change rate and hsCRP baseline were 0.835 (0.789 to 0.881), 0.818 (0.770 to 0.867), 0.691 (0.625 to 0.756) and 0.616 (0.554 to 0.678), respectively. For complications ≥CDC grade 3, the AUC (95% CI) of PCT-24 hours, PCT change and PCT change rate were 0.662 (0.543 to 0.780), 0.643 (0.514 to 0.772) and 0.627 (0.494 to 0.761), respectively. The AUC (95% CI) of CRP-24 hours and hsCRP baseline were 0.649 (0.527 to 0.771) and 0.639 (0.530 to 0.748), respectively.

CONCLUSIONS

PCT-24 hours, CRP-24 hours, the change of perioperative PCT and CRP were valuable predictors of major complications occurring within 30 days after non-cardiac surgery in the elderly.

TRIAL REGISTRATION NUMBER

China Clinical Trial Registry: ChiCTR1900026223.

Procalcitonin as a biomarker to guide treatments for patients with lower respiratory tract infections

INTRODUCTION

Lower respiratory tract infections are amongst the main causes for hospital/intensive care unit admissions and antimicrobial prescriptions. In order to reduce antimicrobial pressure, antibiotic administration could be optimized through procalcitonin-based algorithms.

AREAS COVERED

In this review, we discuss the performances of procalcitonin for the diagnosis and the management of community-acquired and ventilator-associated pneumonia. We provide up-to-date evidence and deliver clear messages regarding the purpose of procalcitonin to reduce unnecessary antimicrobial exposure.

EXPERT OPINION

Antimicrobial pressure and resulting antimicrobial resistances are a major public health issue as well as a daily struggle in the management of patients with severe infectious diseases, especially in intensive care units where antibiotic exposure is high. Procalcitonin-guided antibiotic administration has proven its efficacy in reducing unnecessary antibiotic use in lower respiratory tract infections without excess in mortality, hospital length of stay or disease relapse. Procalcitonin-guided algorithms should be implemented in wards taking care of patients with severe infections. However, procalcitonin performances are different regarding the setting of the infection (community versus hospital-acquired infections) the antibiotic management (start or termination of antibiotic) as well as patient's condition (immunosuppressed or in shock) and we encourage the physicians to be aware of these limitations.

Neutrophil-lymphocyte ratio as a predictive marker for postoperative infectious complications: A systematic review and meta-analysis

Objective

Postoperative infection is a common but costly complication. The neutrophil-lymphocyte ratio is a promising marker for the identification of postsurgical infectious events. We aimed to perform this meta-analysis to assessed the accuracy of the neutrophil-lymphocyte ratio for the prediction of postsurgical infection.

Methods

We searched PubMed, Embase, Web of Science, and Cochrane Library without language restriction from their inceptions to April 2022, and checked reference lists of included studies. Studies were included if they assessed predictive accuracy of neutrophil-lymphocyte ratio for postsurgical infection. We estimated its predictive value and explored the source of heterogeneity. The Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool was used to assess methodological quality and the Deeks' test to evaluate publication bias. The bivariate model and hierarchical summary receiver operating characteristic (HSROC) curve were used for meta-analysis and generated a summary receiver operating characteristic space (ROC) curve.

Results

Our search returned 379 reports, of which 12 fulfilled the inclusion criteria, accounting for 4375 cases. The bivariate analysis yielded a pooled sensitivity of 0.77 (95%C.I.: 0.65-0.85) and specificity of 0.78 (95%C.I.: 0.67-0.86). Pooled positive LR and negative LR were 3.48 (95%C.I.: 2.26-5.36) and 0.30 (95%C.I.: 0.20-0.46), respectively. A negative LR of 0.30 reduces the post-test probability to 2% for a negative test result. The area under of receiver operating characteristic curve was 0.84 (95%C.I.: 0.80-0.87). Subgroups comparisons revealed difference by study design, surgical site, presentence of implant, time of sampling, type of infection event and prevalence of infection. The Deeks' test showed no publication bias. The sensitivity analysis showed no study affected the robustness of combined results.

Conclusions

Low-certainty evidence suggests that the neutrophil-lymphocyte ratio is a helpful marker for predicting postoperative infectious complication. The negative predictive value of the neutrophil-lymphocyte ratio enables for reliable exclusion of postoperative infection.Trial registrationPROSPERO registration number CRD42022321197. Registered on 27 April 2022.

Influence of Renal Dysfunction on the Differential Behaviour of Procalcitonin for the Diagnosis of Postoperative Infection in Cardiac Surgery

Background: procalcitonin is a valuable marker in the diagnosis of bacterial infections; however, the impairment of renal function can influence its diagnostic precision. The objective of this study is to evaluate the differential behaviour of procalcitonin, as well as its usefulness in the diagnosis of postoperative pulmonary infection after cardiac surgery, depending on the presence or absence of impaired renal function. Materials and methods: A total of 805 adult patients undergoing cardiac surgery with extracorporeal circulation (CBP) were prospectively recruited, comparing the behaviour of biomarkers between the groups with and without postoperative pneumonia and according to the presence or absence of renal dysfunction. Results: Pulmonary infection was diagnosed in 42 patients (5.21%). In total, 228 patients (28.32%) presented postoperative renal dysfunction. Procalcitonin was significantly higher in infected patients, even in the presence of renal dysfunction. The optimal procalcitonin threshold differed markedly in patients with renal dysfunction compared to patients without renal dysfunction (1 vs. 0.78 ng/mL p < 0.05). The diagnostic accuracy of procalcitonin increased significantly when the procalcitonin threshold was adapted to renal function. Conclusions: Procalcitonin is an accurate marker of postoperative infection in cardiac surgery, even in the presence of renal dysfunction. Renal function is an important determinant of procalcitonin levels and, therefore, its diagnostic thresholds must be adapted in the presence of renal dysfunction.

The diagnostic accuracy of procalcitonin in infectious patients after cardiac surgery: a systematic review and meta-analysis

Cardiac surgery with cardiopulmonary bypass (CPB) induces an acute inflammatory response that may lead to a systemic inflammatory response syndrome. The interest in procalcitonin (PCT) in the diagnosis of bacterial infection in patients after cardiac surgery remains less defined. The aim of this meta-analysis is to prospectively examine the discriminatory power of PCT as markers of infection in hospitalized patients with after cardiac surgery. The bivariate generalized nonlinear mixed-effect model and the hierarchical summary receiver operating characteristic model were used to estimate the pooled sensitivity, specificity and summary receiver operating characteristic curve. The pooled sensitivity and specificity were 0.81 (95% CI 0.75-0.87) and 0.78 (95% CI 0.73-0.83), respectively. The pooled positive likelihood ratio, and negative likelihood ratio of PCT were 3.74 (95% CI 2.98-4.69) and 0.24 (95% CI 0.17-0.32), respectively. The pooled area under the summary receiver operating characteristic curve of PCT using the HSROC method was 0.87 (95% CI 0.84- 0.90). This study indicated that PCT is a promising marker for the diagnosis of sepsis for those patients who undergo cardiac surgery.

Procalcitonin in special patient populations: Guidance for antimicrobial therapy

PURPOSE

Procalcitonin (PCT) is an endogenous hormone that increases reliably in response to bacterial infection, and measurement of serum PCT levels is recommended to help guide antimicrobial therapy. The utility of PCT assessment in special patient populations (eg, patients with renal dysfunction, cardiac compromise, or immunocompromised states and those undergoing acute care surgery) is less clear. The evidence for PCT-guided antimicrobial therapy in special populations is reviewed.

SUMMARY

In the presence of bacterial infection, nonneuroendocrine PCT is produced in response to bacterial toxins and inflammatory cytokines, resulting in markedly elevated levels of serum PCT. Cytokine induction in nonbacterial inflammatory processes activated by acute care surgery may alter the interpretation of PCT levels. The reliability of PCT assessment has also been questioned in patients with renal dysfunction, cardiac compromise, or immunosuppression. In many special populations, serum PCT may be elevated at baseline and increase further in the presence of infection; thus, higher thresholds for diagnosing infection or de-escalating therapy should be considered, although the optimal threshold to use in a specific population is unclear. Procalcitonin-guided antimicrobial therapy may be recommended in certain clinical situations.

CONCLUSION

Procalcitonin may be a reliable marker of infection even in special populations with baseline elevations in serum PCT. However, due to unclear threshold values and the limited inclusion of special populations in relevant clinical trials, PCT levels should be considered along with clinical criteria, and antibiotics should never be initiated or withheld based on PCT values alone. Procalcitonin measurement may have a role in guiding de-escalation of antibiotic therapy in special populations; however, the clinician should be aware of disease states and concomitant therapies that may affect interpretation of results.

Procalcitonin in clinical practice: from diagnosis of sepsis to antibiotic therapy

A diagnostic algorithm that allows for the rapid identification of sepsis and possibly guides the appropriate antimicrobial therapy application is the cornerstone to obtaining effective treatment and better results. The use of emerging surrogate markers could significantly improve clinical practice, but the validity and clinical utility have been proved only for very few of them, and their availability in clinical routine is limited. For this purpose, numerous scientific evidence has indicated procalcitonin as a marker linked to sepsis and its evolution. This review aims to retrace the main evidence relating to the use of procalcitonin in sepsis. We analyzed the primary studies in the literature and the existing meta-analysis evaluating the behavior of procalcitonin as a marker of bacterial sepsis, its prognostic power, and its ability to influence antibiotic therapy. Recent evidence has suggested that procalcitonin could be an efficient marker for diagnosing sepsis and its therapeutic management in many types of patients. The choice of the appropriate timing to initiate and suspend antibiotic therapy, with obvious clinical advantages, the favorable effects could also include reducing health costs, both avoiding the administration of inappropriate antibiotic therapies, and reducing the duration of hospitalization. Moreover, limited studies reported high procalcitonin levels in coronavirus disease 2019 patients with a worse prognosis. Despite the considerable evidence in favor of the potential of procalcitonin as an index for managing septic patients, there are conflicting data that deserve specific and detailed studies.

Procalcitonin and C-Reactive Protein for Bacterial Infection Diagnosis in Elderly Patients After Traumatic Orthopedic Surgery

BACKGROUND

Biomarkers prove valuable for diagnosing postoperative bacterial infection, but data in elderly patients are scarce. Here we analyze how procalcitonin and C-reactive protein (CRP) perform for bacterial infection diagnosis after traumatic orthopedic surgery in elderly patients.

METHODS

We included all patients admitted to our perioperative geriatrics unit after traumatic orthopedic surgery. Patients on antibiotics, presenting preoperative bacterial infection, or without procalcitonin measurement were excluded. Clinical and biological data were collected prospectively. Medical charts were reviewed by three experts blinded to biomarker results to assess bacterial infection diagnosis. Areas under the curve and 90%-specificity thresholds were analyzed for baseline procalcitonin and CRP levels and relative variations.

RESULTS

Analysis included 229 patients (median age 86 years, hip fracture 83%), of which 40 had bacterial infection (pneumonia [n = 23], urinary tract infection [n = 8]; median delay to onset: 2 days post-admission). For bacterial infection diagnosis, the computed areas under the curve were not significantly different (procalcitonin-baseline 0.64 [95% confidence interval: 0.57-0.70]; procalcitonin-relative variation 0.65 [0.59-0.71]; CRP-baseline 0.68 [0.61-0.74]; CRP-relative variation 0.70 [0.64-0.76]). The 90%-specificity thresholds were 0.75 µg/L for procalcitonin-baseline, +62% for procalcitonin-variation, 222 mg/L for CRP-baseline, +111% for CRP-variation.

CONCLUSIONS

Diagnostic performances of procalcitonin and CRP were not significantly different. Baseline levels and relative variations of these biomarkers showed little diagnostic value after traumatic orthopedic surgery in elderly patients.

Procalcitonin Concentration Measured Within the First Days of Cardiac Surgery Is Predictive of Postoperative Infections in Neonates: A Case-Control Study

Increased procalcitonin concentration (PCT) is known to be reliable for the identification of infections even in the presence of the non-specific systemic inflammatory response seen after cardiopulmonary bypass (CPB), whereas increased C-reactive protein concentration (CRP) is not. The present work explored the ability of neonate PCT measured early after cardiac surgery to identify postoperative infections. This was a retrospective case-control study, where PCT was matched between patients with and without infections according to the patient's age, the CPB length, the use of deep hypothermic circulatory arrest (DHCA), and the postoperative day (POD). The accuracy in the prediction of infections was ascertained and cutoff thresholds were identified. 144 neonates were eligible, and 89 pairs of measurements from 94 patients were analyzed. PCT was a good predictor of infections within POD4, and was a better predictor when compared with CRP at POD1 and POD2. The sum of PCT (pg mL^-1) and CRP (mg L^-1) > 33 on POD1 or POD2 predicted infections with a 0.68 sensitivity and a 0.82 specificity, and a sum  > 49.36 on POD3 or POD4 predicted infections with a 0.82 sensitivity and a 0.93 specificity. In patients with DHCA, PCT was higher than in those without DHCA, and was not predictive of infections. The accuracy of PCT to identify infections after neonatal cardiac surgery is better than that of CRP when measured within 48 h of surgery. The sum of the two markers measured early after surgery is an excellent predictor of postoperative infections.

Prognostic value of biomarkers after cardiopulmonary bypass in pediatrics: The prospective PANCAP study

Objective

To assess the usefulness of procalcitonin, pro-adrenomedullin and pro-atrial natriuretic peptide as predictors of need for mechanical ventilation and postoperative complications (need for inotropic support and bacterial infection) in critically ill pediatric patients after cardiopulmonary bypass.

Design

A prospective, observational study

Setting

Pediatric intensive care unit.

Patients

Patients under 18 years old admitted after cardiopulmonary bypass.

Measuraments and main results

Serum levels of procalcitonin, pro-adrenomedullin and pro-atrial natriuretic peptide were determined immediately after bypass and at 24–36 hours. Their values were correlated with the need for mechanical ventilation, inotropic support and bacterial infection. One hundred eleven patients were recruited. Septal defects (30.6%) and cardiac valve disease (17.1%) were the most frequent pathologies. 40.7% required mechanical ventilation, 94.6% inotropic support and 15.3% presented invasive bacterial infections. Pro-adrenomedullin and pro-atrial natriuretic peptide showed significant high values in patients needing mechanical ventilation. Cut-off values higher than 1.22 nmol/L and 215.3 pmol/L, respectively for each biomarker, may indicate need for mechanical ventilation with an AUC of 0.721 and 0.746 at admission and 0.738 and 0.753 at 24–36 hours, respectively but without statistical differences. Pro-adrenomedullin and procalcitonin showed statistically significant high values in patients with bacterial infections.

Conclusions

After bypass, pro-adrenomedullin and pro-atrial natriuretic peptide are suitable biomarkers to predict the need for mechanical ventilation. Physicians should be alert if the values of these markers are high so as not to progress to early extubation. Procalcitonin is useful for predicting bacterial infection. This is a preliminary study and more clinical studies should be done to confirm the value of pro-adrenomedullin and pro-atrial natriuretic peptide as biomarkers after cardiopulmonary bypass.

Diagnostic and prognostic value of presepsin vs. established biomarkers in critically ill patients with sepsis or systemic inflammatory response syndrome

BACKGROUND

Inflammatory biomarkers may aid to distinguish between systemic inflammatory response syndrome (SIRS) vs. sepsis. We tested the hypotheses that (1) presepsin, a novel biomarker, can distinguish between SIRS and sepsis, and (2) higher presepsin levels will be associated with increased severity of illness and (3) with 28-day mortality, outperforming traditional biomarkers.

METHODS

Procalcitonin (PCT), C-reactive protein (CRP), presepsin, and lactate were analyzed in 60 consecutive patients (sepsis and SIRS, n=30 per group) on day 1 (D1) to D3 (onset sepsis, or after cardiac surgery). The systemic organ failure assessment (SOFA) score was determined daily.

RESULTS

There was no difference in mortality in sepsis vs. SIRS (12/30 vs. 8/30). Patients with sepsis had higher SOFA score vs. patients with SIRS (11±4 vs. 8±5; p=0.023), higher presepsin (AUC=0.674; p<0.021), PCT (AUC=0.791; p<0.001), CRP (AUC=0.903; p<0.0001), but not lactate (AUC=0.506; p=0.941). Unlike other biomarkers, presepsin did not correlate with SOFA on D1. All biomarkers were associated with mortality on D1: presepsin (AUC=0.734; p=0.0006; best cutoff=1843 pg/mL), PCT (AUC=0.844; p<0.0001), CRP (AUC=0.701; p=0.0048), and lactate (AUC=0.778; p<0.0001). Multiple regression analyses showed independent associations of CRP with diagnosis of sepsis, and CRP and lactate with mortality. Increased neutrophils (p=0.002) and decreased lymphocytes (p=0.007) and monocytes (p=0.046) were also associated with mortality.

CONCLUSIONS

Presepsin did not outperform traditional sepsis biomarkers in diagnosing sepsis from SIRS and in prognostication of mortality in critically ill patients. Presepsin may have a limited adjunct value for both diagnosis and an early risk stratification, performing independently of clinical illness severity.

Early Kinetics of Procalcitonin in Predicting Surgical Outcomes in Type A Aortic Dissection Patients

BACKGROUND

In cardiac surgery, elevation of procalcitonin (PCT) could be observed postoperatively in the absence of any evidence of infection and also seems to be a prognostic marker. PCT levels measured in patients undergoing Type A aortic dissection (TAAD) were used to determine prognostic values for complications and surgical outcomes.

METHODS

Measurements of PCT, C-reactive protein (CRP), and leukocyte count were observed in TAAD surgery patients (n = 251; average age: 49.02 ± 12.83 years; 78.5% male) at presurgery (T0) and 24 h (T1), 48 h (T2), and 7 days (T3) postsurgery. PCT clearance (PCTc) on days 2 and 7 was calculated: (PCTday1- PCTday2/day7)/PCTday1 × 100%. Endotracheal intubation duration, length of stay (LOS) in the Intensive Care Unit (ICU)/hospital, and complications were recorded.

RESULTS

PCT peaked 24 h postsurgery (median 2.73 ng/ml) before decreasing. Correlation existed between PCT levels at T1 and duration of cardiopulmonary bypass (P = 0.001, r = 0.278). Serum PCT concentrations were significantly higher in nonsurvivor and multiple organ dysfunction syndrome groups on all postoperative days. PCT levels at T1 correlated with length of time of ventilation support and ICU/hospital LOS. Comparing PCT values of survivors versus nonsurvivors, a PCT cutoff level of 5.86 ng/ml at T2 had high sensitivity (70.6%) and specificity (74.3%) in predicting in-hospital death. PCTc-day 2 and 7 were significantly higher in survivor compared with nonsurvivor patients (38% vs. 8%, P= 0.012, 83% vs. -39%, P< 0.001). A PCTc-day 7 cutoff point of 48.7% predicted survival with high sensitivity (77.8%) and specificity (81.8%).

CONCLUSIONS

PCT level and PCTc after TAAD surgery might serve as early prognostic markers to predict postoperative outcome. PCT measurement may help identify high-risk patients.

Procalcitonin Is a Better Biomarker than C-Reactive Protein in Newborns Undergoing Cardiac Surgery: The PROKINECA Study

OBJECTIVES

To assess the kinetics of procalcitonin (PCT) and C-reactive protein (CRP) in newborns after cardiothoracic surgery (CS), with and without cardiopulmonary bypass, and to assess whether PCT was better than CRP in identifying sepsis in the first 72 hours after CS.

PATIENTS AND METHODS

This is a prospective study of newborns admitted to the neonatal intensive care unit after CS.

INTERVENTIONS

PCT and CRP were sequentially drawn 2 hours before surgery and at 0, 12, 24, 48, and 72 hours after surgery.

RESULTS

A total of 65 patients were recruited, of which 14 were excluded because of complications. We compared the kinetics of PCT and CRP after CS in bypass and non-bypass groups without sepsis; there were no differences in the PCT values at any time (24 hours, P = 0.564; 48 hours, P = 0.117; 72 hours, P = 0.076). Thirty-five patients needed bypass, of whom four were septic (11.4%). Significant differences were detected in the PCT values on comparing the septic group to the nonseptic group at 48 hours after cardiopulmonary bypass (P = 0.018). No differences were detected in the CRP values in these groups. A suitable cutoff for sepsis diagnosis at 48 hours following bypass would be 5 ng/mL, with optimal area under the curve of 0.867 (confidence interval 0.709–0.958), P < 0.0001, and sensitivity and specificity of 87.5% (29.6–99.7) and 72.6% (53.5–86.4), respectively.

CONCLUSION

This is a preliminary study but PCT seems to be a good biomarker in newborns after CS. Values over 5 ng/mL at 48 hours after CS should alert physicians to the high risk of sepsis in these patients.

Procalcitonin is useful whereas C-reactive protein is not, to predict complications following coronary artery bypass surgery

Background: The respective value of procalcitonin (PCT) and C-reactive protein (CRP) as markers of postoperative complications after coronary bypass surgery is unclear. Therefore, complications during one week after surgery were studied to evaluate the predictive role of PCT and CRP changes during the immediate postoperative period.

Methods: Thirty-two patients, in whom an uneventful immediate postoperative course was anticipated, were prospectively enrolled and followed-up to the 7th postoperative day. At the end of the follow-up, patients were divided into two groups. Group A were patients with an uncomplicated postoperative course and Group B were patients with a complicated postoperative course.

Results: Serum samples were drawn for PCT and CRP determination after induction of anesthesia (baseline), at the end of surgery and daily until postoperative day 2. Baseline serum PCT concentrations were 0.119 ± 0.09 and 0.209 ± 0.21 ng/mL in Groups A and B, respectively (NS). Serum PCT concentration increased compared with baseline in both groups during the first two days after surgery. The increase in serum PCT concentration was significantly greater in Group B than A patients ( p<0.0002). Considering a perioperative abnormal cut-off value of > 0.5 ng/mL, there were none in Group A versus 57% in Group B ( p<0.0001). Baseline serum CRP concentrations were 1.449 ± 1.30 and 1.589 ± 1.35 ng/mL in Groups A and B, respectively (NS). After surgery, CRP increased significantly compared with baseline in both groups. When changes in time-varying variables were included in a logistic model, complications were predicted by changes (between baseline and end of surgery values) of PCT (coefficient=9.410; t=2.18) and heart rate (coefficient=0.075; t=1.57), whereas changes of CRP, white blood cells, mean blood and central venous pressures did not contribute statistically. The model constant was -4.827 (t= -2.43) and the ROC curve area was 0.8971. Thus, absolute PCT changes of 0.20, 0.40 and 0.60 ng/mL carry an approximate risk of 5, 26 and 69%, respectively, of postoperative complications in the time frame of this study.

Conclusions: A postoperative serum PCT concentration of >0.5 ng/mL is highly suggestive of a postoperative complication. CRP changes do not contribute to predictive information.

Procalcitonin in the Early Course Post Pediatric Cardiac Surgery

OBJECTIVE

Procalcitonin has emerged as a promising infection marker, but previous reports from small-sized studies suggest nonspecific elevation of procalcitonin after pediatric heart surgery. As procalcitonin is increasingly used as a marker for infection in the PICU, the aim of this study was to identify factors associated with postoperative procalcitonin elevation and to investigate the role of procalcitonin as an early marker of outcome after cardiac surgery.

DESIGN

Prospective observational study.

SETTING

Single, tertiary referral PICU.

PATIENTS

Patients aged 0-16 years following cardiac surgery with or without cardiopulmonary bypass.

INTERVENTIONS

Procalcitonin was measured in all patients at admission to PICU, and on postoperative day 1 and 2. Outcome variables included major adverse event, length of stay in PICU, postoperative renal failure requiring temporary dialysis, duration of mechanical ventilation and duration of inotropic support. A major adverse event was defined as cardiac arrest, need for postoperative extracorporeal life support or death within 3 months of cardiac surgery.

MEASUREMENTS AND MAIN RESULTS

In 221 included patients who underwent 232 operations, procalcitonin at admission to PICU was significantly associated with mechanical ventilation prior to surgery (p = 0.001), preoperative myocardial dysfunction (p = 0.002), duration of cardiopulmonary bypass (p < 0.001), intraoperative cross-clamp time (p = 0.015), and serum lactate at admission (p < 0.001). Patients suffering a major adverse event and patients with postoperative renal failure had significantly higher procalcitonin levels at admission to PICU (p = 0.04 and 0.01, respectively). Furthermore, procalcitonin levels at admission correlated significantly with the length of stay in the PICU (p = 0.005), time on mechanical ventilation (p = 0.03), and duration of inotropic support (p = 0.02).

CONCLUSIONS

Elevated levels of procalcitonin in the early phase after pediatric cardiac surgery are a marker for increased risk for major adverse events and postoperative renal failure and increased postoperative morbidity.

Serum Procalcitonin as a Valuable Diagnostic Tool in the Early Detection of Infectious Complications after Open Abdominal Aortic Repair

BACKGROUND

Aortic aneurysm repair is a resolutive and effective surgical operation, which can be associated with severe postoperative complications. Procalcitonin (PCT) in clinical practice could play a role in early diagnosis and monitoring of therapy for complications, especially infections, making for timely and more effective interventions. Our aim was to investigate whether PCT could be a predictive marker in early diagnosis of infectious complications after open abdominal aortic surgery.

METHODS

Eighty-three consecutive patients who underwent elective open aortic repair at our institution were enrolled. Blood samples were taken before surgery, and each day over the 7-day postoperative period, and measurement of serum PCT, C-reactive protein (CRP), and leukocytes levels were carried out. Data regarding clinical progress, instrumental examinations, and blood chemistry were prospectively collected.

RESULTS

Postoperative infectious complications occurred in 24 patients. Within 30 days, 1 death occurred. In the study sample, we found a significant difference in PCT curves of patients with and without infectious complications, especially on third postoperative day (POD; P = 0.004). On analysis of the area under the curve (AUC curve), PCT was shown to be a fair predictor in distinguishing cases with infectious complications (AUC, 0.765 on third POD; CI, 0.638-0.877). Conversely, other inflammatory markers commonly used (leucocytes and CRP) had similar trends in patients with and without postoperative infections.

CONCLUSIONS

On the basis of the results collected in this pilot study, despite some limitations, PCT could be considered a better marker of infectious complications after open abdominal aortic repair, when compared with other routinely used parameters.

Admission levels of serum amyloid a and procalcitonin are more predictive of the diagnosis of acute appendicitis compared with C-reactive protein

BACKGROUND

Acute appendicitis is the commonest surgical emergency, but its diagnosis can be elusive with a negative appendicectomy rate of 20%. The aims of this study were to investigate the potential value of the markers of acute inflammation, serum amyloid A (SAA), and serum procalcitonin (ProCT), in the diagnosis of acute appendicitis in adults and to compare that with the commonly used serum C-reactive protein (CRP).

METHODS

Adult patients presenting with acute right lower abdominal pain and a clinical suspicion of acute appendicitis were included. Blood samples were obtained within 6 hours of admission for rapid serum CRP assay and for end-of-recruitment batch analysis of SAA and serum ProCT concentrations.

RESULTS

A total of 147 patients (81 males) with a mean (±SD) age of 36 (±17) years were recruited. Appendicitis was confirmed histologically in 61 of 72 patients (84.7%) who underwent appendicectomy. A post hoc analysis revealed a diagnostic sensitivity and specificity for SAA of 92% and 72%, ProCT of 85% and 74%, and CRP of 75% and 72%, respectively. The receiver operator characteristics for the area under the curves showed that SAA (P=0.011) and ProCT (P=0.037) significantly exceeded CRP in the prediction of acute appendicitis on admission.

CONCLUSIONS

The measurement of SAA and serum ProCT on admission in patients with clinically suspected acute appendicitis seems to outperform serum CRP in aiding that diagnosis.

Procalcitonin-guided antibiotic therapy for septic patients in the surgical intensive care unit

In critically ill patients, elucidating those patients with the systemic inflammatory response syndrome (SIRS) from an infectious source (sepsis), versus those who have SIRS without infection, can be challenging since the clinical features are the same.

Even with strict monitoring and testing, 39–98 % of patients with SIRS will never have bacteriological confirmation of an infection, and 6–17 % of patients with a documented infection will not show signs of SIRS. Due to this overlap, an extensive amount of research has been performed to investigate ways of determining and separating SIRS from infection, compared to SIRS due to trauma, surgical stress, or other non-infectious causes. This review article will discuss the recommended and peer-approved use of procalcitonin in septic patients in the intensive care unit and its use as a guide to antibiotic initiation and termination. The article will focus on the prospective randomized trials (Level 1 evidence) that have been conducted, and lesser levels of evidence will be referenced as needed to substantiate a conclusion.

The literature documents multiple benefits of using procalcitonin as a guide to cost savings and appropriate termination of antibiotics by its use as a new objective marker of bacteremia that was previously not available. This article will show that antibiotics should be terminated when the procalcitonin level falls below 0.5 ng/mL.

Use of a Combination Biomarker Algorithm To Identify Medical Intensive Care Unit Patients with Suspected Sepsis at Very Low Likelihood of Bacterial Infection

Sepsis remains a diagnostic challenge in the intensive care unit (ICU), and the use of biomarkers may help in differentiating bacterial sepsis from other causes of systemic inflammatory syndrome (SIRS). The goal of this study was to assess test characteristics of a number of biomarkers for identifying ICU patients with a very low likelihood of bacterial sepsis. A prospective cohort study was conducted in a medical ICU of a university hospital. Immunocompetent patients with presumed bacterial sepsis were consecutively enrolled from January 2012 to May 2013. Concentrations of nine biomarkers (α-2 macroglobulin, C-reactive protein [CRP], ferritin, fibrinogen, haptoglobin, procalcitonin [PCT], serum amyloid A, serum amyloid P, and tissue plasminogen activator) were determined at baseline and at 24 h, 48 h, and 72 h after enrollment. Performance characteristics were calculated for various combinations of biomarkers for discrimination of bacterial sepsis from other causes of SIRS. Seventy patients were included during the study period; 31 (44%) had bacterial sepsis, and 39 (56%) had other causes of SIRS. PCT and CRP values were significantly higher at all measured time points in patients with bacterial sepsis. A number of combinations of PCT and CRP, using various cutoff values and measurement time points, demonstrated high negative predictive values (81.1% to 85.7%) and specificities (63.2% to 79.5%) for diagnosing bacterial sepsis. Combinations of PCT and CRP demonstrated a high ability to discriminate bacterial sepsis from other causes of SIRS in medical ICU patients. Future studies should focus on the use of these algorithms to improve antibiotic use in the ICU setting.

Postoperative pro-adrenomedullin levels predict mortality in thoracic surgery patients: comparison with Acute Physiology and Chronic Health Evaluation IV Score*

OBJECTIVES

Risk assessment in ICU patients using commonly used prognostic models may be influenced using different data definitions and by errors in data collection. We investigated whether a set of biomarkers (procalcitonin, MR-pro-adrenomedullin, CT-pro-endothelin-1, CT-pro-arginine vasopressin, and MR-pro-atrial natriuretic peptide), alone or as a panel, could be useful in postoperative risk assessment for hospital mortality in comparison with the Acute Physiology and Chronic Health Evaluation IV score.

DESIGN

In a prospective observational cohort study, we analyzed 800 consecutive patients undergoing elective cardiac surgery. We assessed biomarker levels on admission to the ICU and every 6 hours thereafter for 24 hours. For every postoperative time point and for every biomarker, we determined the predictive value for hospital mortality and made a comparison with the Acute Physiology and Chronic Health Evaluation IV score.

SETTING

Intensive care of an academic referral hospital.

PATIENTS

A total of 800 consecutive patients undergoing elective cardiac surgery.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

MR-pro-adrenomedullin is a good predictor of mortality (c-statistic at time point 6 hr after admission to the ICU, 0.940; 95% CI, 0.918-0.956) and performed better than the Acute Physiology and Chronic Health Evaluation IV score (c-statistic, 0.842; 95% CI, 0.811-0.868). The c-statistic did not change significantly on the time points 6, 12, and 18 hours after admission. Using a cutoff value for proadrenomedullin taken 6 hours after admission on ICU (time point 2) of 3.2 nmol/L sensitivity was 81.8% and specificity 93.9%, the positive likelihood ratio was 13.3, positive predictive value was 31.0%, and negative predictive value was 99.4%. Patients with a MR-pro-adrenomedullin above this cutoff level had an odds ratio of 68.9 (95% CI, 22.2-213.1) for not surviving their hospital stay. The other biomarkers had less predictive power.

CONCLUSIONS

In elective cardiac surgery, MR-pro-adrenomedullin measured between 6 and 18 hours after admission to the ICU is a better predictor of hospital mortality in comparison with the Acute Physiology and Chronic Health Evaluation IV score.

Predicting mortality and morbidity after elective cardiac surgery using vasoactive and inflammatory biomarkers with and without the EuroSCORE model

BACKGROUND

In cardiac surgery, preoperative mortality risk assessment tools like the EuroSCORE help to guide physicians in optimizing perioperative care of patients. We investigated the value of preoperative levels of inflammatory (procalcitonin [PCT]) and vasoactive (C-terminal pro-arginine vasopressin [CT-proAVP], midregional pro-atrial natriuretic peptide [MR-proANP], midregional proadrenomedullin [MR-proADM], and C-terminal pro-endothelin-1 [CT-proET-1]) biomarkers for risk assessment of mortality and morbidity and compared it with the EuroSCORE.

METHODS

We performed a prospective observational cohort study in a single-center academic medical hospital and analyzed 746 consecutive patients undergoing elective cardiac surgery. In a directly preoperative blood sample, we assessed PCT, CT-proAVP, MR-proANP, MR-proADM, and CT-proET-1 levels.

RESULTS

In single-variable logistic regression models, all biomarkers predicted 30-day mortality. The biomarkers CT-proET-1 (C statistic, 0.785; 95% CI, 0.687-0.883) and MR-proADM (C statistic, 0.780; 95% CI, 0.671-0.889) predicted 30-day mortality. For the EuroSCORE, the C statistic was 0.689 (95% CI, 0.594-0.784). There was a significant improvement in the prediction of 30-day mortality when the EuroSCORE was combined with MR-proADM (C statistic, 0.792; 95% CI, 0.699-0.884) or CT-proET-1 (C statistic, 0.798; 95% CI, 0.715-0.880). The model with EuroSCORE, MR-proADM, and CT-proET1 had the highest C statistic of 0.803 (95% CI, 0.717-0.890) and was significantly better than the EuroSCORE alone.

CONCLUSIONS

In elective cardiac surgery, preoperative levels of MR-proADM and CT-proET-1 are predictors of 30-day mortality and could improve the predictive accuracy of the EuroSCORE. Further research should confirm the place of these new biomarkers in the prediction of mortality and identification of patients at risk.

Evaluation of fever and infections in cardiac surgery patients

Fever following cardiac surgery is common and may be infectious or noninfectious in etiology. In this article, we review the major causes of postoperative fever while highlighting special considerations in cardiac surgery patients. We also outline a structured approach to evaluation and present an overview of diagnostic and management considerations for mediastinitis, postpericardiotomy syndrome, prosthetic valve endocarditis, aortic vascular graft infections, and ventricular assist device infections.

The efficacy of procalcitonin as a biomarker in the management of sepsis: slaying dragons or tilting at windmills?

BACKGROUND

Sepsis is defined as systemic inflammatory response syndrome (SIRS) in the context of an underlying infectious process, and is associated with high rates of morbidity and mortality, particularly when initial therapy is delayed. Numerous biomarkers, including but not limited to cytokines (interleukins-2 and -6 [IL-2, IL-6] and tumor necrosis factor-α [TNF-α]), leukotrienes, acute-phase proteins (C-reactive protein [CRP]), and adhesion molecules, have been evaluated and rejected as unsuitable for the diagnosis of sepsis, predicting its severity, and guiding its treatment. Most recently, procalcitonin (PCT) has been suggested as a novel biomarker that may be useful in guiding therapeutic decision making in the management of sepsis. This article assesses critically the published literature on the clinical utility of PCT concentrations for guiding the treatment of sepsis in adult patients.

METHODS

A comprehensive search of all published studies of the use of serum concentrations of PCT to guide the treatment of sepsis in adult patients (1996 to 2011) was conducted with PubMed and Google Scholar. The search focused on the value of PCT concentrations to guide the diagnosis, prognosis, monitoring, and escalation and de-escalation of antbiotic therapy in these patients. Keywords searched included "procalcitonin," "sepsis," "sepsis biomarker," "sepsis diagnosis," "sepsis prognosis," "sepsis mortality," "antibiotic escalation," "antibiotic de-escalation," "antibiotic duration," and "antimicrobial stewardship."

RESULTS

Forty-six trials evaluating the efficacy of PCT concentrations in diagnosing sepsis have been published, with 39 of these trials yielding positive results and 7 yielding negative results. Wanner et al. published the largest study (n=405) demonstrating that peak PCT concentrations occur early after injury in both patients with sepsis and those with multiple organ dysfunction syndrome (MODS). Among 17 trials assessing the prognostic value of PCT concentrations with regard to clinical outcome and morbidity, 12 trials yielded positive results and five showed negative or equivocal results. Reith et al. published the largest study of the prognostic use of PCT concentrations (n=246), demonstrating that median PCT values on post-operative days (POD) one, four, and 10 were predictive of mortality in patients with abdominal sepsis (p<0.01). Among 14 trials of the utility of PCT concentrations for establishing an infectious cause of sepsis, 13 yielded positive results and only one yielded negative results. The largest study of this use of PCT concentrations, conducted by Baykut et al. (n=400), evaluated these concentrations in post-operative patients with infection, and demonstrated that concentrations of PCT remained elevated until POD 4, with a second increase observed between POD 4 and POD 6. In uninfected patients, PCT concentrations began to decrease on POD 2. Only a single study has assessed the utility of PCT concentrations in guiding the escalation of antibiotic therapy, and its results were negative. Specifically, Jensen et al. (n=1,200) compared a PCT-guided antibiotic escalation strategy with the standard of care for sepsis and found no difference in outcomes. They also found that the PCT group had a longer average stay in the intensive care unit (ICU), greater rates of mechanical ventilation, and a decreased estimated glomerular filtration rate (eGFR). Among four trials focusing on PCT concentrations and antibiotic de-escalation, all showed positive results with the measurement of PCT concentrations. The largest such study, by Bouadma et al. (n=621), demonstrated a four-day decrease in antibiotic duration when PCT concentrations were used to guide therapy relative to the study arm given the standard of care, with no increase in mortality (p=0.003).

CONCLUSIONS

The diagnostic value of serum PCT concentrations for discriminating among SIRS, sepsis, severe sepsis, and septic shock remains to be established. Although higher PCT concentrations suggest a systemic bacterial infection as opposed to a viral, fungal, or inflammatory etiology of sepsis, serum PCT concentrations do not correlate with the severity of sepsis or with mortality. At present, PCT concentrations are solely investigational with regard to determining the timing and appropriateness of escalation of antimicrobial therapy in sepsis. Nevertheless, serum PCT concentrations have established utility in monitoring the clinical response to medical and surgical therapy for sepsis, and in surveillance for the development of sepsis in burn and ICU patients, and may have a role in guiding the de-escalation of antibiotic therapy.

Procalcitonin as a predictive marker for surgical site infection in elective colorectal cancer surgery

PURPOSE

Surgical site infection (SSI) is a frequent complication of elective surgery for colorectal cancer. The classical clinical markers of infection-elevations in white blood cell count, C-reactive protein (CRP) level, and body temperature-do not precisely predict SSI after elective colorectal resection. The objective of this study was to evaluate the efficacy of procalcitonin (PCT) as a tool for diagnosis of SSI in elective surgery for colorectal cancer.

METHODS

A total of 114 consecutive patients undergoing elective colorectal resection for cancer were evaluated. Routine blood samples, for determining PCT level, CRP plasma concentration, and white blood cell count, were obtained on postoperative days (POD) 1 and 3. Predictive values for each of the laboratory markers were examined.

RESULTS

SSI was diagnosed in 18 (15.7 %) of 114 patients. Patients with SSI exhibited significantly higher PCT levels (on PODs 1 and 3) and CRP levels (on POD 3) than did patients without SSI. According to receiver operating characteristic analysis, PCT showed the highest area under the curve (AUC) for predicting SSI on both PODs 1 and 3 (AUC, 0.76 and 0.77, respectively). Multivariate logistic regression analysis showed that PCT (on PODs 1 and 3) was an independent predictor for SSI (odds ratio = 14.41 and 9.79, respectively).

CONCLUSION

Serum PCT is more reliable laboratory marker for the early diagnosis of SSI after elective colorectal cancer surgery, compared with conventional inflammatory indicators. PCT could serve as an additional diagnostic tool for the early identification of SSI to improve clinical decision making.

A composite score combining procalcitonin, C-reactive protein and temperature has a high positive predictive value for the diagnosis of intensive care-acquired infections

Background

Nosocomial infection diagnosis in the intensive care unit (ICU) remains a challenge. We compared routine measurements of procalcitonin (PCT), C-reactive protein (CRP), white blood cell count (WBC) and temperature in the detection of ICU-acquired infections.

Method

Prospective observational cohort study in a University hospital Medicosurgical ICU. All patients admitted to the ICU ≥ 5 days (n = 141) were included into two groups, either infected (documented infection, n = 25) or non-infected (discharged from the ICU without diagnosis of infection, n = 88).

Results

PCT, CRP, WBC and temperature progression from day −4 (D-4) to day 0 (D0) (day of infection diagnosis or ICU discharge) was analysed. Differences (Δ) were calculated as D0 levels minus the lowest preceding value. D0 PCT and CRP were significantly increased in infected compared to non-infected patients (median, 1^st and 3^rd quartiles): 3.6 ng/mL (0.92-25) for PCT, 173 mg/L (126–188) for CRP versus 0.02 ng/mL (0.1-0.9) and 57 mg/mL (31–105) respectively (p < 0.0001). In multivariate analysis, D0 temperature > 38.6°C, PCT > 1.86 ng/mL, and CRP > 88 mg/L, performed well (AUCs of 0.88, 0.84, and 0.88 respectively). The sensitivity/specificity profiles of each marker (76%/94% for temperature, 68%/91% for PCT, and 92%/70% for CRP) led to a composite score (0.068 × D0 PCT + 0.005 × D0 CRP + 0.7 × temperature) more highly specific than each component (AUC of 0.90 and sensitivity/specificity of 80%/97%).

Conclusion

Combining CRP, PCT and temperature is an approach which may increase of nosocomial infection detection in the ICU.

Use of inflammatory molecules to predict the occurrence of fever in onco-hematological patients with neutropenia

Febrile neutropenia remains a frequent complication in onco-hematological patients, and changes in the circulating level of inflammatory molecules (IM) may precede the occurrence of fever. The present observational prospective study was carried out to evaluate the behavior of plasma tumor necrosis factor alpha (TNF-α), soluble TNF-α I and II receptors (sTNFRI and sTNFRII), monocyte chemoattractant protein-1 [MCP-1 or chemokine (c-c motif) ligand 2 (CCL2)], macrophage inflammatory protein-1α (MIP-1α or CCL3), eotaxin (CCL11), interleukin-8 (IL-8 or CXCL8), and interferon-inducible protein-10 (IP-10 or CXCL10) in 32 episodes of neutropenia in 26 onco-hematological patients. IM were tested on enrollment and 24-48 h before the onset of fever and within 24 h of the first occurrence of fever. Eight of 32 episodes of neutropenia did not present fever (control group) and the patients underwent IM tests on three different occasions. sTNFRI levels, measured a median of 11 h (1-15) before the onset of fever, were significantly higher in patients presenting fever during follow-up compared to controls (P = 0.02). Similar results were observed for sTNFRI and CCL2 levels (P = 0.04 for both) in non-transplanted patients. A cut-off of 1514 pg/mL for sTNFRI was able to discriminate between neutropenic patients with or without fever during follow-up, with 65% sensitivity, 87% specificity, and 93% positive predictive value. Measurement of the levels of plasma sTNFRI can be used to predict the occurrence of fever in neutropenic patients.

Procalcitonin as a diagnostic marker for sepsis: a systematic review and meta-analysis

BACKGROUND

Procalcitonin is a promising marker for identification of bacterial infections. We assessed the accuracy and clinical value of procalcitonin for diagnosis of sepsis in critically ill patients.

METHODS

We searched Medline, Embase, ISI Web of Knowledge, the Cochrane Library, Scopus, BioMed Central, and Science Direct, from inception to Feb 21, 2012, and reference lists of identified primary studies. We included articles written in English, German, or French that investigated procalcitonin for differentiation of septic patients--those with sepsis, severe sepsis, or septic shock--from those with a systemic inflammatory response syndrome of non-infectious origin. Studies of healthy people, patients without probable infection, and children younger than 28 days were excluded. Two independent investigators extracted patient and study characteristics; discrepancies were resolved by consensus. We calculated individual and pooled sensitivities and specificities. We used I(2) to test heterogeneity and investigated the source of heterogeneity by metaregression.

FINDINGS

Our search returned 3487 reports, of which 30 fulfilled the inclusion criteria, accounting for 3244 patients. Bivariate analysis yielded a mean sensitivity of 0 · 77 (95% CI 0 · 72-0 · 81) and specificity of 0 · 79 (95% CI 0 · 74-0 · 84). The area under the receiver operating characteristic curve was 0 · 85 (95% CI 0 · 81-0 · 88). The studies had substantial heterogeneity (I(2)=96%, 95% CI 94-99). None of the subgroups investigated--population, admission category, assay used, severity of disease, and description and masking of the reference standard--could account for the heterogeneity.

INTERPRETATION

Procalcitonin is a helpful biomarker for early diagnosis of sepsis in critically ill patients. Nevertheless, the results of the test must be interpreted carefully in the context of medical history, physical examination, and microbiological assessment.

FUNDING

Ministry of Education and Research, the Deutsche Forschungsgemeinschaft, Thuringian Ministry for Education, Science and Culture, the Thuringian Foundation for Technology, Innovation and Research, and the German Sepsis Society.

Approach to postoperative fever in pediatric cardiac patients

Fever in the postoperative period in children undergoing surgery for congenital heart disease is fairly common and tends to cause anxiety to both the surgeon and the patient. Such fever is associated with the metabolic response to trauma, systemic response to the cardiopulmonary bypass, hypothermia, presence of drainage tubes, drugs, blood transfusion as well as infections. Establishing the diagnosis requires proper assessment of the patient with focused history, targeted physical examination and judicious use of investigations with the knowledge of the common causes.

Persistent systemic inflammation in chronic critical illness

Chronic critical illness (CCI) is syndrome of neuromuscular weakness, brain dysfunction, malnutrition, endocrinopathies, and symptom distress. Two conceptual themes may be useful in discussing CCI. The first is a clinical roadmap in which a patient suffers an acute critical illness, survives the initial insult, but yet is unable to be liberated from the ventilator. The second framework considers the effect of systemic inflammation and CCI, linking acute CCI risk factors with the common clinical features of CCI. Given the association between common CCI antecedents and inflammation, attempts to control and balance the pro-inflammatory and anti-inflammatory mediators should begin as early as possible and continue throughout the ICU stay. Since surrogate measures such as biomarkers often fail to predict the effect of interventions, the focus should be on the outcomes patients experience. As of now, providing evidence-based, high quality ICU management of patients at risk for CCI appears to be the best strategy of care.

Procalcitonin: a useful biomarker to discriminate infection after cardiopulmonary bypass in children

OBJECTIVE

To determine whether procalcitonin discriminates between postcardiopulmonary bypass inflammatory syndrome and infectious complication in children better than does C-reactive protein.

DESIGN

Prospective study of children admitted to the intensive care unit after cardiopulmonary bypass.

PATIENTS

Classified according to a diagnosis of systemic inflammatory response syndrome and bacterial infection or systemic inflammatory response syndrome but no bacterial infection. Two hundred thirty-one cases were recruited.

MEASUREMENT AND MAIN RESULTS

Procalcitonin, C-reactive protein, and leukocyte count were measured daily from surgery until day 3. Twenty-two patients were infected (9.5%). Significant differences were detected in the procalcitonin values of the infected group vs. the noninfected group, especially at day 2 (p = .000). There were no differences in the C-reactive protein values. The optimal cutoff for procalcitonin was >2 ng/mL at day 1 and above 4 ng/mL at the day 2. There was a greater sensitivity and specificity than with C-reactive protein as an infection predictor.

CONCLUSION

Procalcitonin is useful in the diagnosis of bacterial infection after cardiopulmonary bypass. Because procalcitonin kinetics are different in postcardiopulmonary bypass patients, the cutoff to diagnose infection should be different from the normal cutoff.

Emergency surgery for native mitral valve endocarditis: the impact of septic and cardiogenic shock

BACKGROUND

Limited information exists about the real impact of the etiology of shock on early and late outcome after emergency surgery in acute native mitral valve endocarditis (ANMVE). This multicenter study analyzed the impact of the etiology of shock on early and late outcome in patients with ANMVE.

METHODS

Data were collected in eight institutions. Three hundred-seventy-nine ANMVE patients undergoing surgery on an emergency basis between May 1991 and December 2009 were eligible for the study. According to current criteria used for the differential diagnosis of shock, patients were retrospectively assigned to one of three groups: group 1, no shock (n=154), group 2, cardiogenic shock (CS [n=118]), and group 3, septic shock (SS [n=107]). Median follow-up was 69.8 months.

RESULTS

Early mortality was significantly higher in patients with SS (p<0.001). At multivariable logistic regression analysis, compared with patients with CS, patients with SS had more than 3.8 times higher risk of death. That rose to more than 4 times versus patients without shock. In addition, patients with SS had 4.2 times and 4.3 times higher risk of complications compared with patients with CS and without shock, respectively. Sepsis was also an independent predictor of prolonged artificial ventilation (p=0.04) and stroke (p=0.003) whereas CS was associated with a higher postoperative occurrence of low output syndrome and myocardial infarction (p<0.001). No difference was detected between groups in 18-year survival, freedom from endocarditis, and freedom from reoperation.

CONCLUSIONS

Our study suggests that emergency surgery for ANMVE in patients with CS achieved satisfactory early and late results. In contrast, the presence of SS was linked to dismal early prognosis. Our findings need to be confirmed by further larger studies.

Procalcitonin as an adjunctive biomarker in sepsis

Sepsis can sometimes be difficult to substantiate, and its distinction from non-infectious conditions in critically ill patients is often a challenge. Serum procalcitonin (PCT) assay is one of the biomarkers of sepsis. The present study was aimed to assess the usefulness of PCT assay in critically ill patients with suspected sepsis. The study included 40 patients from the intensive care unit with suspected sepsis. Sepsis was confirmed clinically and/or by positive blood culture. Serum PCT was assayed semi-quantitatively by rapid immunochromatographic technique (within 2 hours of sample receipt). Among 40 critically ill patients, 21 had clinically confirmed sepsis. There were 12 patients with serum PCT ≥10 ng/ml (8, blood culture positive; 1, rickettsia; 2, post-antibiotic blood culture sterile; and 1, non-sepsis); 7 patients with PCT 2-10 ng/ml (4, blood culture positive; 1, falciparum malaria; 2, post-antibiotic blood culture sterile); 3 patients with PCT of 0.5 to 2 ng/ml (sepsis in 1 patient); and 18 patients with PCT < 0.5 ng/ml (sepsis in 2 patients). Patients with PCT ≥ 2 ng/ml had statistically significant correlation with the presence of sepsis (P<0.0001). The PCT assay revealed moderate sensitivity (86%) and high specificity (95%) at a cut-off ≥ 2 ng/ml. The PCT assay was found to be a useful biomarker of sepsis in this study. The assay could be performed and reported rapidly and provided valuable information before availability of culture results. This might assist in avoiding unwarranted antibiotic usage.

Procalcitonin level as an aid for the diagnosis of bacterial infections following pediatric cardiac surgery

PURPOSE

The aim of the present study was to determine if blood procalcitonin can serve as an aid to differentiate between bacterial and nonbacterial cause of fever in children after cardiac surgery.

MATERIALS AND METHODS

A nested case-control study of children who underwent open cardiac surgery in critical care units of fourth-level pediatric hospital was performed. Blood samples for procalcitonin level were collected 1 day before operation; 1 hour postoperation; on postoperative days 1, 2, and 5; and on the day of fever, when it occurred.

RESULTS

Of 665 children who underwent cardiac bypass surgery, 126 had a febrile episode postoperatively, 47 children with a proven bacterial infection and 79 without bacterial infection. Among the 68 children in whom fever developed within the first 5 postoperative days, procalcitonin level at fever day was significantly higher in those with bacterial infection (n = 16) than in those without infection (n = 52). Similarly, among the 58 children in whom fever developed after day 5 postoperation, a significant difference was found in procalcitonin level at fever day between those with (n = 31) and without (n = 27) bacterial infection.

CONCLUSION

During the critical early and late periods after cardiac surgery in children, procalcitonin level may help to differentiate patients with bacterial infection from patients in whom the fever is secondary to nonbacterial infectious causes.

[Kinetics of C-reactive protein and procalcitonin after paediatric cardiac surgery]

INTRODUCTION AND OBJECTIVES

The systemic inflammatory response syndrome developed after cardiac surgery impedes the detection of complications. The aim of our study was to examine the behaviour of C-reactive protein (CRP) and procalcitonin (PCT), as well as to evaluate its relationship with severity and to analyse its usefulness in the identification of complications.

METHODS

A total of 59 children who underwent cardiac surgery with cardiopulmonary bypass were prospectively studied. CRP and PCT were determined after surgery and at 24, 48 and 72 hours. The relationships between both parameters and the clinical severity were analysed (evaluated with PRISM and TISS scoring systems), as well as with the incidence of complications (infectious and haemodynamics).

RESULTS

Serum concentrations of CRP and PCT increased in the first 24 hours after surgery, with a gradual decrease over the following days. There was no association between CRP and severity or development of complications. A moderate correlation was observed between PCT after surgery, at 24 and 48 hours, and PRISM (r=0.548; 0.434 and 0.446) and a low correlation between PCT and TISS. When studying the identification of complications, we obtained cut-off values of PCT>0.17ng/ml (Ss 73.3%; Sp 72.2%) and PCT>1.98ng/ml (Ss 57.1%; Sp 87%) immediately and 48 hours after surgery. No differences were found in CPR and PCT levels among patients with infectious and haemodynamics complications.

CONCLUSIONS

CPR does not correlate with the severity or the incidence of complications after paediatric cardiac surgery. PCT correlates with clinical severity and may be able to detect post-surgical complications.

Eosinopenia: Is it a good marker of sepsis in comparison to procalcitonin and C-reactive protein levels for patients admitted to a critical care unit in an urban hospital?

INTRODUCTION

The role of eosinopenia as a marker of sepsis has recently been evaluated. The aim of our study was to test the value of eosinopenia as a diagnostic marker of sepsis in comparison to procalcitonin and C-reactive protein levels.

METHODS

A prospective study of critically ill adult patients admitted to the medical intensive care unit at an urban hospital. Procalcitonin, C-reactive protein (CRP) levels and eosinophil counts were measured on admission. Patients were classified as non-infected or infected by the medical residents, fellows, and attendings.

RESULTS

A total of 68 patients were enrolled into the study. At a cut-off value of 70 mg/L, the CRP level yielded a sensitivity of 94%, a specificity of 84%, a positive predicted value (PPV) of 83% and a negative predicted value (NPV) of 94%. At a cutoff value of 1.5 μg/L, the sensitivity of the procalcitonin test was 84%, specificity of 92%, PPV 90%, and NPV of 87%. The eosinophil cell count (cutoff of 50 cells/mm(3)) produced a sensitivity of 81%, specificity of 65%, a PPV of 66%, and a NPV of 80%. The comparison of the eosinophil cell count (<50 cells/mm(3)) and procalcitonin levels among the non-infected and infected groups showed a significant statistical difference (Fisher exact test, P = .0239). There was no statistical difference observed when comparisons were made between CRP levels and eosinophil count (Fisher exact test, P = .12). There was also a lack of significant statistical difference when CRP levels were compared to procalcitonin levels (Fisher exact test, P = .49).

CONCLUSION

Eosinopenia is a very sensitive yet not specific serological marker of sepsis in the intensive care unit and can be utilized to guide physicians in the diagnosis of sepsis.