Procalcitonin for the differential diagnosis of infectious and non-infectious systemic inflammatory response syndrome after cardiac surgery

Combination of Creatinine with Inflammatory Biomarkers (PCT, CRP, hsCRP) for Predicting Postoperative ICU Admissions for Elderly Patients

INTRODUCTION

The number of elderly patients who require surgery as their primary treatment has increased rapidly in recent years. Among 300 million people globally who underwent surgery every year, patients aged 65 years and over accounted for more than 30% of cases. Despite medical advances, older patients remain at higher risk of postoperative complications. Early diagnosis and effective prediction are essential requirements for preventing serious postoperative complications. In this study, we aim to provide new biomarker combinations to predict the incidence of postoperative intensive care unit (ICU) admissions > 24 h in elderly patients.

METHODS

This investigation was conducted as a nested case-control study, incorporating 413 participants aged ≥ 65 years who underwent non-cardiac, non-urological elective surgeries. These individuals underwent a 30-day postoperative follow-up. Before surgery, peripheral venous blood was collected for analyzing serum creatinine (Scr), procalcitonin (PCT), C-reactive protein (CRP), and high-sensitivity CRP (hsCRP). The efficacy of these biomarkers in predicting postoperative complications was evaluated using receiver operating characteristic (ROC) curve analysis and area under the curve (AUC) values.

RESULTS

Postoperatively, 10 patients (2.42%) required ICU admission. Regarding ICU admissions, the AUCs with 95% confidence intervals (CIs) for the biomarker combinations of Scr × PCT and Scr × CRP were 0.750 (0.655-0.845, P = 0.007) and 0.724 (0.567-0.882, P = 0.015), respectively. Furthermore, cardiovascular events were observed in 14 patients (3.39%). The AUC with a 95% CI for the combination of Scr × CRP in predicting cardiovascular events was 0.688 (0.560-0.817, P = 0.017).

CONCLUSION

The innovative combinations of biomarkers (Scr × PCT and Scr × CRP) demonstrated efficacy as predictors for postoperative ICU admissions in elderly patients. Additionally, the Scr × CRP also had a moderate predictive value for postoperative cardiovascular events.

TRIAL REGISTRATION

China Clinical Trial Registry, ChiCTR1900026223.

Procalcitonin for the diagnosis of postoperative bacterial infection after adult cardiac surgery: a systematic review and meta-analysis

BACKGROUND AND AIMS

Patients undergoing cardiac surgery are subject to infectious complications that adversely affect outcomes. Rapid identification is essential for adequate treatment. Procalcitonin (PCT) is a noninvasive blood test that could serve this purpose, however its validity in the cardiac surgery population is still debated. We therefore performed a systematic review and meta-analysis to estimate the accuracy of PCT for the diagnosis of postoperative bacterial infection after cardiac surgery.

METHODS

We included studies on adult cardiac surgery patients, providing estimates of test accuracy. Search was performed on PubMed, EmBase and WebOfScience on April 12th, 2023 and rerun on September 15th, 2023, limited to the last 10 years. Study quality was assessed with the QUADAS-2 tool. The pooled measures of performance and diagnostic accuracy, and corresponding 95% Confidence Intervals (CI), were calculated using a bivariate regression model. Due to the variation in reported thresholds, we used a multiple-thresholds within a study random effects model for meta-analysis (diagmeta R-package).

RESULTS

Eleven studies were included in the systematic review, and 10 (2984 patients) in the meta-analysis. All studies were single-center with observational design, five of which with retrospective data collection. Quality assessment highlighted various issues, mainly concerning lack of prespecified thresholds for the index test in all studies. Results of bivariate model analysis using multiple thresholds within a study identified the optimal threshold at 3 ng/mL, with a mean sensitivity of 0.67 (0.47-0.82), mean specificity of 0.73 (95% CI 0.65-0.79), and AUC of 0.75 (IC95% 0.29-0.95). Given its importance for practice, we also evaluated PCT's predictive capability. We found that positive predictive value is at most close to 50%, also with a high prevalence (30%), and the negative predictive value was always > 90% when prevalence was < 20%.

CONCLUSIONS

These results suggest that PCT may be used to help rule out infection after cardiac surgery. The optimal threshold of 3 ng/mL identified in this work should be confirmed with large, well-designed randomized trials that evaluate the test's impact on health outcomes and on the use of antibiotic therapy. PROSPERO Registration number CRD42023415773. Registered 22 April 2023.

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 and Early Postoperative Infection After Pediatric Cardiopulmonary Bypass Surgery

OBJECTIVES

Systemic inflammation and bacterial infections are critical occurrences after pediatric cardiac surgery. Elevated white blood cell count and C-reactive protein cannot discriminate between these two conditions in the early postoperative period. The aim of this study was to understand whether procalcitonin (PCT) values within 48 hours of surgery could be a useful marker of postoperative infection.

DESIGN

Retrospective observational study.

SETTING

The study was performed in a teaching hospital.

PARTICIPANTS

All patients ≤six years of age.

INTERVENTIONS

Cardiac surgery on cardiopulmonary bypass from January 1, 2017 to January 1, 2020.

MEASUREMENT AND MAIN RESULTS

PCT, white blood cell count, and C-reactive protein values were measured at intensive care unit admission and at 24 and 48 hours after surgery. All positive cultures in the first seven days after surgery were recorded. Out of 177 consecutive patients, 22 (12%) developed infections. PCT at 48 hours after surgery was the only laboratory predictor of infections in the first seven days after surgery (p = 0.02). Receiver operating curve analyses on PCT values at 48 hours identified an optimal cut-off value of 1.85 ng/mL in the overall population. Area under the curve was 0.63, sensitivity 63%, and specificity 69%.

CONCLUSIONS

In light of this preliminary result, the clinical relevance and predictive accuracy of PCT are promising in patients with increasing values of PCT but need to be confirmed in a larger sample.

Correlation of Redox Status with Procalcitonin and C-reactive Protein in Septic Patients

Based on the role of oxidative stress in the pathophysiological mechanisms of sepsis and the importance of PCT as a clinically applicable biomarker for early detection of inflammatory response initiation, we aimed this study at examining the correlation between PCT levels and oxidative stress parameters (prooxidants and antioxidants) in patients with sepsis. This study was designed as a case-series prospective clinical study which involved 103 critically ill patients and 17 healthy participants with diagnosis of sepsis/septic shock (over 18 years of age, both gender) admitted to the Intensive Care Unit (ICU) of Valjevo General Hospital in Serbia. All subjects were divided into patients who were operated on/underwent surgery before sampling and have sepsis (n = 24), patients who were operated on/underwent surgery before sampling and have septic shock (n = 25), patients who were not operated on/did not undergo surgery before sampling and have sepsis (n = 26), patients who were not operated on/did not undergo surgery before sampling and have septic shock (n = 28), and participants who are healthy (n = 17). PCT has confirmed a positive correlation with prooxidants and type of critical illness, and performing surgical intervention diminished oxidative stress in patients with septic shock. Prognosis in critically ill patients was strongly associated with PCT levels but not with nonspecifically C-reactive protein.

Immature granulocytes as a sepsis predictor in patients undergoing cardiac surgery

OBJECTIVES

Usefulness of immature granulocyte percentage (IG%) to discriminate between postoperative non-infective systemic inflammatory response syndrome (SIRS) and sepsis was tested in cardiac surgical patients.

METHODS

A retrospective analysis of 124 patients who developed non-infective SIRS and sepsis after elective cardiac surgery was performed. Predictive ability of IG% to predict sepsis was compared to procalcitonin (PCT), white blood cell count, temperature and different biomarker combinations using receiver operating characteristic and logistic regression analysis. The optimal cut-off points, diagnosis sensitivity and specificity were calculated.

RESULTS

There were 44 patients diagnosed with sepsis and 80 patients with non-infective SIRS. In receiver operating characteristic analysis, area under the curve was higher for IG% (0.71) and PCT (0.72) compared to white blood cell count (0.62) and temperature (0.58). The best cut-off value for IG% was 1.45% (sensitivity 70.5%, specificity 60%) and 1.43 µg/l for PCT (sensitivity 65.9%, specificity 75%). The combination of IG% and PCT provided the best sepsis prediction (area under the curve of 0.8, sensitivity 63.6% and specificity 88.8%).

CONCLUSIONS

In cardiac surgical patients, IG% is a helpful marker with the moderate ability to discriminate between sepsis and non-infective SIRS, comparable to serum PCT. A combination of these parameters increased the test's overall predictive ability by improving its specificity.

Multiplex polymerase chain reaction to diagnose bloodstream infections in patients after cardiothoracic surgery

Background

Sepsis and other infectious complications are major causes of mortality and morbidity in patients after cardiac surgery. Whereas conventional blood culture (BC) suffers from low sensitivity as well as a reporting delay of approximately 48–72 h, real-time multiplex polymerase chain reaction (PCR) based technologies like “SeptiFast” (SF) might offer a fast and reliable alternative for detection of bloodstream infections (BSI). The aim of this study was to compare the performance of SF with BC testing in patients suspected of having BSI after cardiac surgery.

Methods

Two hundred seventy-nine blood samples from 169 individuals with suspected BSI were analyzed by SF and BC. After excluding results attributable to contaminants, a comparison between the two groups were carried out. Receiver operating characteristic (ROC) curves were generated to determine the accuracy of clinical and laboratory values for the prediction of positive SF results.

Results

14.7% (n = 41) of blood samples were positive using SF and 17.2% (n = 49) using BC (n.s. [p > 0.05]). In six samples SF detected more than one pathogen. Among the 47 microorganisms identified by SF, only 11 (23.4%) could be confirmed by BC. SF identified a higher number of Gram-negative bacteria than BC did (28 vs. 12, χ² = 7.97, p = 0.005). The combination of BC and SF increased the number of detected microorganisms, including fungi, compared to BC alone (86 vs. 49, χ² = 13.51, p < 0.001). C-reactive protein (CRP) (21.7 ± 11.41 vs. 16.0 ± 16.9 mg/dl, p = 0.009), procalcitonin (28.7 ± 70.9 vs. 11.5 ± 30.4 ng/dl, p = 0.015), and interleukin 6 (IL 6) (932.3 ± 1306.7 vs. 313.3 ± 686.6 pg/ml, p = 0.010) plasma concentrations were higher in patients with a positive SF result. Using ROC analysis, IL-6 (AUC 0.836) and CRP (AUC 0.804) showed the best predictive values for positive SF results.

Conclusion

The SF test represent a valuable method for rapid etiologic diagnosis of BSI in patients after cardiothoracic surgery. In particular this method applies for individuals with suspected Gram-negative blood stream. Due to the low performance in detecting Gram-positive pathogens and the inability to determine antibiotic susceptibility, it should be used in addition to BC only (Pilarczyk K, et al., Intensive Care Med Exp ,3(Suppl. 1):A884, 2015).

Value of evaluating procalcitonin kinetics in diagnosis of infections in patients undergoing laparoscopic radical cystectomy

Postsurgery infection is a common complication after laparoscopic radical cystectomy (LRC) followed by urinary diversion. White blood cell (WBC) values and C-reactive protein (CRP) are routinely used as markers for infection, but lack of specificity and their elevation is often delayed in clinically significant events. In this study, we aimed to investigate the value of procalcitonin (PCT) kinetics in assisting early diagnosis of infection in patients undergoing LRC.The patients' medical records between May 2013 and May 2016 were reviewed retrospectively. WBC, CRP, and PCT plasma levels as well as clinical symptoms were registered in 306 patients preoperatively (day 0), and 5 consecutive days postoperatively. Based on microbiological and clinical data, patients were grouped into noninfection- (NI-) and infection- (I-) groups. The day of new onset infection was observed were defined as day t0 and the day after that as day t1. For the NI-group, the day on which PCT was at the peak was defined as day t1 and the previous day as day t0.Of the 306 patients, 46 (15.03%) have proven infection. PCT levels were analogous at day t0:NI-group [median (interquartile range)]: 0.69(1.99) vs I-group [median (interquartile range)]: 1.0[0.75], P = .1. PCT levels were significantly increased at day t1 in the I-group[median (interquartile range)]:2.9(1.3) vs NI-group[median (interquartile range)]: 1.3(1.5), P < .01. The area under the curve for the prediction of infection was 0.72 [95% confidence interval (CI) = 0.63-0.81] for the absolute value of PCT; and for delta PCT:0.88 (95% CI = 0.81-0.94), P < .01. The optimal cut-off value was 0.79 ng/mL with the highest Youden index of 0.80 for delta-PCT to indicate infection. Neither absolute values nor changes in CRP, or WBC could predict infection better. The "delta" was considered as the changes in the absolute values (subtracting day t0 from day t1) of PCT, CRP, and WBC.This study suggest that early elevation of PCT within the first 24 hours of new onset infection, interpreted with clinical results, appears to be a promising indicator for the diagnosis of infections following LRC.

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.