Postoperative plasma concentrations of procalcitonin after different types of surgery

Procalcitonin and C-reactive protein as early predictors in patients at high risk of colorectal anastomotic leakage

OBJECTIVE

To assess the diagnostic value of C-reactive protein (CRP) and procalcitonin (PCT) for anastomotic leakage (AL) following colorectal surgery.

METHODS

We retrospectively analyzed data for patients who underwent colorectal surgery at our hospital between November 2019 and December 2023. CRP and PCT were measured postoperatively to compare patients with/without AL, and changes were compared between low- and high-risk groups. Receiver operating characteristic (ROC) curve analysis was used to assess the diagnostic accuracy of CRP and PCT to identify AL in high-risk patients.

RESULTS

Mean CRP was 142.53 mg/L and 189.57 mg/L in the low- and high-risk groups, respectively, on postoperative day (POD)3. On POD2, mean PCT was 2.75 ng/mL and 8.16 ng/mL in low- and high-risk patients, respectively; values on POD3 were 3.53 ng/mL and 14.86 ng/mL, respectively. The areas under the curve (AUC) for CRP and PCT on POD3 were 0.71 and 0.78, respectively (CRP cut-off: 235.64 mg/L; sensitivity: 96%; specificity: 89.42% vs PCT cut-off: 3.94 ng/mL; sensitivity: 86%; specificity: 93.56%; AUC: 0.78). The AUC, sensitivity, and specificity for the combined diagnostic ability of CRP and PCT on POD3 were 0.92, 90%, and 100%, respectively (cut-off: 0.44).

CONCLUSIONS

Combining PCT and CRP on POD3 enhances the diagnostic accuracy for AL.

Advances of presepsin in sepsis-associated ARDS

This article reviews the correlation between presepsin and sepsis and the resulting acute respiratory distress syndrome (ARDS). ARDS is a severe complication of sepsis. Despite the successful application of protective mechanical ventilation, restrictive fluid therapy, and neuromuscular blockade, which have effectively reduced the morbidity and mortality associated with ARDS, the mortality rate among patients with sepsis-associated ARDS remains notably high. The challenge lies in the prediction of ARDS onset and the timely implementation of intervention strategies. Recent studies have demonstrated significant variations in presepsin (PSEP) levels between patients with sepsis and those without, particularly in the context of ARDS. Moreover, these studies have revealed substantially elevated PSEP levels in patients with sepsis-associated ARDS compared to those with nonsepsis-associated ARDS. Consequently, PSEP emerges as a valuable biomarker for identifying patients with an increased risk of sepsis-associated ARDS and to predict in-hospital mortality.

Procalcitonin kinetics following abdominal aortic surgery and its value for postoperative intestinal ischaemia detection

OBJECTIVE

The purpose of our study was to describe perioperative kinetics of procalcitonin (PCT) in patients undergoing aortic surgery, to compare the kinetics in the open abdominal aortic aneurysm (AAA) repair and aortobifemoral bypass for aortoiliac occlusive disease (AIOD), and to evaluate the ability of PCT to detect intestinal ischaemia.

METHODS

A prospective non-randomized observational cohort study in 80 patients (62 men and 18 women) undergoing elective aortic surgery was performed. Serum PCT was measured at baseline and defined intraoperative and postoperative timepoints up to postoperative day 7. MRI contrast-enhanced imaging was used to detect intestinal ischaemia.

RESULTS

The comparison of the AAA and AIOD cohort did not show any significant difference in PCT levels. Patients with intestinal ischaemia had higher serum PCT at multiple timepoints postoperatively. The most accurate timepoints for early diagnosis were postoperative day 3, followed by 24 h after declamping of the vascular reconstruction, and postoperative day 7. The sensitivity and negative predictive values were 100% in all mentioned timepoints. However, event at the best timepoint the specificity was 89% and the positive predictive value 43%.

CONCLUSIONS

Procalcitonin levels in the postoperative period at proper timepoints might help to detect postoperative intestinal ischaemia. The limitation of this marker is its low specificity for intestinal ischaemia and low positive predictive value. The highest value of this marker is that it can rule out this complication because normal PCT levels mean that intestinal ischaemia is very unlikely.

Diagnostic Accuracy of Procalcitonin for Infection After Adult Liver Transplantation: A Meta-Analysis and Systematic Review

Background: Post-operative infection remains a major cause of morbidity and mortality in adults early after liver transplantation (LT). Procalcitonin (PCT) may be a good test method for early diagnosis of post-operative infection and determining its severity. This study was performed to assess the diagnostic accuracy of PCT as a biomarker for infection after LT. Patients and Methods: A meta-analysis and systematic review was conducted for studies reporting diagnostic performance of PCT for infection in adults after LT. Observational studies were evaluated for their reporting of diagnostic accuracy, relevance, and quality. Results: Ten eligible studies assessing 730 patients were included in this meta-analysis and systematic review summarizing the diagnostic value of PCT for post-operative infection in adult liver transplantation. Pooled sensitivity and specificity with corresponding 95% confidence interval were 69% (95% confidence interval [CI], 54-81; heterogeneity I2 = 82.4%) and 88% (95% CI, 82-92; I2 = 52.7%), respectively. The diagnostic odd ratio (DOR) was 16 (95% CI, 10-25; I2 = 76.4%). The summary receiver operator characteristic (SROC) of PCT for post-operative infection was 0.88. There was a wide range of variability in the cutoff values, ranging from 0.22 to 42.80 ng/mL. Heterogeneity was reduced by excluding studies that focused on pediatric LT recipients. Conclusions: Procalcitonin is a moderately accurate diagnostic marker for post-operative infection in adult LT. Additionally, the diagnostic performance can be improved by combining it with other inflammatory biomarkers. This article provides the research direction for post-operative infection control.

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.

Management of Intra-Abdominal Infections: The Role of Procalcitonin

Patients with intra-abdominal sepsis suffer from significant mortality and morbidity. The main pillars of treatment for intra-abdominal infections are (1) source control and (2) early delivery of antibiotics. Antibiotic therapy should be started as soon as possible. However, the duration of antibiotics remains a matter of debate. Prolonged antibiotic delivery can lead to increased microbial resistance and the development of nosocomial infections. There has been much research on biomarkers and their ability to aid the decision on when to stop antibiotics. Some of these biomarkers include interleukins, C-reactive protein (CRP) and procalcitonin (PCT). PCT's value as a biomarker has been a focus area of research in recent years. Most studies use either a cut-off value of 0.50 ng/mL or an >80% reduction in PCT levels to determine when to stop antibiotics. This paper performs a literature review and provides a synthesized up-to-date global overview on the value of PCT in managing intra-abdominal infections.

AACC Guidance Document on the Clinical Use of Procalcitonin

BACKGROUND

Procalcitonin (PCT), a peptide precursor of the hormone calcitonin, is a biomarker whose serum concentrations are elevated in response to systemic inflammation caused by bacterial infection and sepsis. Clinical adoption of PCT in the United States has only recently gained traction with an increasing number of Food and Drug Administration-approved assays and expanded indications for use. There is interest in the use of PCT as an outcomes predictor as well as an antibiotic stewardship tool. However, PCT has limitations in specificity, and conclusions surrounding its utility have been mixed. Further, there is a lack of consensus regarding appropriate timing of measurements and interpretation of results. There is also a lack of method harmonization for PCT assays, and questions remain regarding whether the same clinical decision points may be used across different methods.

CONTENT

This guidance document aims to address key questions related to the use of PCT to manage adult, pediatric, and neonatal patients with suspected sepsis and/or bacterial infections, particularly respiratory infections. The document explores the evidence for PCT utility for antimicrobial therapy decisions and outcomes prediction. Additionally, the document discusses analytical and preanalytical considerations for PCT analysis and confounding factors that may affect the interpretation of PCT results.

SUMMARY

While PCT has been studied widely in various clinical settings, there is considerable variability in study designs and study populations. Evidence to support the use of PCT to guide antibiotic cessation is compelling in the critically ill and in some lower respiratory tract infections but is lacking in other clinical scenarios, and evidence is also limited in the pediatric and neonatal populations. Interpretation of PCT results requires guidance from multidisciplinary care teams of clinicians, pharmacists, and clinical laboratorians.

Use of biomarkers to individualize antimicrobial therapy duration: a narrative review

BACKGROUND

Reducing the overuse of antimicrobials is imperative for the sake of minimizing antimicrobial-associated adverse effects, optimizing resource utilization, and curtailing the rise in multidrug-resistant organisms. Biomarkers reflect the host responses to infection and may assist with minimizing unnecessary antimicrobial usage.

OBJECTIVES

To review the literature pertaining to the performance of biomarkers specifically used to guide the duration of antimicrobial therapy (AMT).

SOURCES

Randomized controlled trials, observational studies, and meta-analyses assessing biomarker-guided approaches to AMT decision-making and their impact on the duration of therapy were reviewed.

CONTENT

Several randomized controlled trials and real-world observational studies have shown that a procalcitonin (PCT)-guided strategy can help clinicians individualize the duration of AMT, particularly among non-critically ill patients hospitalized with suspected respiratory tract infections when using a PCT cut-off value of <0.25 μg/L and critically ill patients with respiratory tract infections or undifferentiated sepsis when using a PCT cut-off value of <0.5 μg/L or ≥80% decline in the peak level. C-reactive protein is a non-specific marker of inflammation that may also assist with an early discontinuation of AMT; however, data are limited. Haematological biomarkers are prone to variance between individuals and are often influenced by medications and non-infectious conditions, making them less reliable for the purposes of AMT decision-making. Novel biomarkers such as multi-protein signatures and host gene expression tests have shown promise as tools to better differentiate between bacterial and non-bacterial infections; clinical studies are needed to determine whether they can be used to help optimize the duration of AMT.

IMPLICATIONS

Studies have demonstrated that a PCT-guided strategy, when utilized appropriately, can help guide clinicians to individualize and often reduce the duration of AMT, especially in patients hospitalized with respiratory tract infections and those admitted to the intensive care unit with suspected respiratory tract infections or sepsis. The impact of utilizing other biomarkers is less clear and requires further study.

The Role of Biomarkers in Influenza and COVID-19 Community-Acquired Pneumonia in Adults

Pneumonia is a growing problem worldwide and remains an important cause of morbidity, hospitalizations, intensive care unit admission and mortality. Viruses are the causative agents in almost a fourth of cases of community-acquired pneumonia (CAP) in adults, with an important representation of influenza virus and SARS-CoV-2 pneumonia. Moreover, mixed viral and bacterial pneumonia is common and a risk factor for severity of disease. It is critical for clinicians the early identification of the pathogen causing infection to avoid inappropriate antibiotics, as well as to predict clinical outcomes. It has been extensively reported that biomarkers could be useful for these purposes. This review describe current evidence and provide recommendations about the use of biomarkers in influenza and SARS-CoV-2 pneumonia, focusing mainly on procalcitonin (PCT) and C-reactive protein (CRP). Evidence was based on a qualitative analysis of the available scientific literature (meta-analyses, randomized controlled trials, observational studies and clinical guidelines). Both PCT and CRP levels provide valuable information about the prognosis of influenza and SARS-CoV-2 pneumonia. Additionally, PCT levels, considered along with other clinical, radiological and laboratory data, are useful for early diagnosis of mixed viral and bacterial CAP, allowing the proper management of the disease and adequate antibiotics prescription. The authors propose a practical PCT algorithm for clinical decision-making to guide antibiotic initiation in cases of influenza and SARS-CoV-2 pneumonia. Further well-design studies are needed to validate PCT algorithm among these patients and to confirm whether other biomarkers are indeed useful as diagnostic or prognostic tools in viral pneumonia.

Clinical Utility of Procalcitonin on Antibiotic Stewardship: A Narrative Review

Procalcitonin (PCT) was discovered as a useful marker for bacterial infection. Following its discovery, there have been a substantial number of clinical studies conducted to evaluate the presence of bacterial infections, and to guide antibiotic treatment by the stratified levels of PCT. Clinical evidence suggests that antibiotic treatment by PCT-guided antibiotic stewardship has been associated with a reduction in antibiotic usage without an increase in adverse outcomes. The use of PCT was approved by the Food and Drug Administration in the United States of America in 2017 to guide antibiotic treatment in sepsis and lower respiratory tract infections (LRTIs). In Korea, the use of PCT for sepsis and for pneumonia was approved in 2015 and 2022, respectively. This review will discuss the clinical utility of PCT on antibiotic stewardship in the management of sepsis and LRTIs including pneumonia.

Impact of a Pharmacist Managed Procalcitonin Program on COVID-19 Respiratory Tract Infection Outcomes and Healthcare Resource Utilization

Patients hospitalized with coronavirus disease 2019 (COVID-19) often receive empiric antibiotic coverage. Procalcitonin (PCT) is a biomarker with Food and Drug Administration–approved guidance cutoffs for antibiotic use in lower respiratory tract infections. Herein we describe the implementation and impact of a pharmacist-managed PCT monitoring program in hospitalized patients with COVID-19. In this quasi-experimental, single-center, retrospective study of a prospective antimicrobial stewardship pharmacist-managed program, inpatients who were severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) polymerase chain reaction positive were reviewed during weekday working hours and evaluated for appropriateness of antibiotic treatment by utilizing the PCT biomarker. As needed, the infectious diseases pharmacist offered feedback around antibiotic discontinuation in patients with PCT values ≤0.25 ng/mL. Adherence to PCT cutoffs, clinical outcomes, and utilization of health care resources were quantified and compared with a time frame immediately preceding the program's implementation. A total of 772 patients hospitalized with COVID-19 were analyzed. The pre-intervention cohort was comprised of 519 patients, and 253 patients were included after program implementation. Antibiotics were prescribed within 72 hours of admission to 232 (44.7%) and 108 (42.7%) patients during the control and intervention phases, respectively. There was no difference in the primary outcome of percentage of patients who received >1 day of antibiotic therapy (23.5% vs 21.7%; P = .849) or in any secondary outcome including hospital length of stay, 30-day readmission rates, or discharge disposition. In a hospital where the majority of COVID-19 patients did not receive empiric antibiotics, the implementation of a pharmacist-managed PCT monitoring program did not significantly decrease antibiotic use or health care resource utilization.

Microwave Ablation Vs Traditional Thyroidectomy for Benign Thyroid Nodules: A Prospective, Non-Randomized Cohort Study

RATIONALE AND OBJECTIVES

To evaluate the efficacy of microwave ablation (MWA) for benign thyroid nodules (BTNs) and compare trauma and complication rates between MWA and traditional thyroidectomy for BTNs.

MATERIALS AND METHODS

84 patients with BTNs were recruited and followed up at 1, 3, 6, and 12months. 56 and 28 patients chose to undergo MWA (group A) and traditional thyroidectomy (group B), respectively. Efficacy was assessed by volume reduction rate (VRR) and therapeutic success rate (TSR) at each follow-up. Trauma was compared using inflammation response parameters, visual analog scale (VAS) scores, quality of life (QOL) and thyroid function measures at 1, 3, and 6 months. Complications rates were also compared.

RESULTS

The VRR was 80.70 ± 18.60%, and TSR was 91.70% at 6-months. Furthermore, the VRR increased to 90.45 ± 11.51%, and TSR increased to 100% at 12-months. C-reactive protein levels were significantly higher in group B on the first postoperative day (POD) (3.89 ± 0.86 mg/mL vs 3.39 ± 0.56 mg/mL, p = 0.002). Visual analog scale scores were significantly lower in group A on the first and second POD. Thyroid stimulating hormone levels were significantly lower in group A at three (1.71 ± 1.12uIU/mL vs 2.37 ± 1.24uIU/mL, p = 0.013) and 6-months (1.34 ± 0.70uIU/mL vs 1.97 ± 0.94uIU/mL, p = 0.002). There were no significant between-group differences in QOL and complication rates.

CONCLUSION

Microwave ablation shows acceptable and promising efficacy. Compared with thyroidectomy, MWA was associated with less trauma and comparable complication rates.

Procalcitonin is one of the predictive factors of dehiscence of the colorectal anastomosis

Background/Aim: Dehiscence of the colorectal anastomosis is one of the most serious complications in digestive surgery that is still present in a large percentage today, which significantly increases the cost of treatment and can lead to death. Due to all the above, early detection of anastomotic dehiscence is very important, as well as the decision on surgical treatment. Procalcitonin (PCT) is thought to be an important marker of inflammation and sepsis. Aim of this paper was to confirm PCT as a marker of great sensitivity in early diagnosis of anastomotic leakage. Methods: The study included patients who underwent surgery for colorectal cancer in the period from 2016 to 2020. Patients were operated according to an elective protocol and with an open surgical approach. In patients, PCT values were measured on the 2nd and 4th postoperative day (POD) to determine the association between elevated PCT values and the onset of dehiscence of the colorectal anastomosis. Results: A study was conducted in 118 patients in whom a stapler colorectal anastomosis was created. Colorectal anastomosis dehiscence occurred in 10 patients. In 4 patients with dehiscence, no re-surgical intervention was required, but they were taken care of by conservative methods. Repeated surgery was performed in 6 patients. In all patients with dehiscence, there was a multiple increase in the value of PCT above normal. Conclusion: PCT has high sensitivity and specificity (85 and 74 % respectively) as a marker in dehiscence of colorectal anastomosis. In this study it was found that PCT values were significantly correlated with the dehiscence of anastomo-sis 2nd POD and especially 4th POD.

Do biomarkers have predictive value in the treatment modality of the patients diagnosed with bowel obstruction?

OBJECTIVES

This study aimed to investigate the ability of the biomarkers to predict the surgery treatment and mortality in patients above 18 years of age who were hospitalized with the diagnosis of bowel obstruction from the emergency department.

METHODS

This is a 2-year retrospective study. The patients' demographic data, laboratory parameters on admission to emergency department, treatment modalities, and the length of hospital stay were recorded. Patients were divided into two groups: conservative and surgical treatment. Statistical analysis was performed to investigate the value of biomarkers in predicting mortality and the need for surgery. Data were analyzed using IBM SPSS version 22.

RESULTS

A total of 179 patients were included in this study. Of these, 105 (58.7%) patients were treated conservative and 74 (41.3%) were treated operatively. The elevated procalcitonin (PCT) level, C-reactive protein, blood urea nitrogen-to-albumin ratio, and lactate-to-albumin ratio were significantly correlated with surgical treatment, length of hospital stay, and mortality. procalcitonin threshold value of 0.13 ng/mL was able to predict the need for surgical treatment, with a sensitivity of 79% and a specificity of 70.3%. Procalcitonin threshold value of 0.65 ng/mL was able to predict the mortality rate of the patients, with a sensitivity of 92.9% and a specificity of 78.1%.

CONCLUSIONS

Biomarkers, especially procalcitonin, may be useful in bowel obstruction treatment management and may predict mortality.

Association Between Procalcitonin and Post-hepatectomy Liver Failure in Hepatocellular Carcinoma Patients

Objectives: Procalcitonin (PCT) has long been proved as an early diagnostic signal for postoperative outcomes. The purpose of this study is to explore the value of serum procalcitonin levels in predicting post-hepatectomy liver failure (PHLF), and further to declarethe relationship between postoperative PCT and short-term prognosis in patients after hepatectomy.

Methods: Clinical data of patients with hepatocellular carcinoma (HCC) who underwent hepatectomy from June 1st, 2019 to September 31st, 2020 at Shanghai Eastern Hepatobiliary Surgery Hospital had been retrospectively analyzed. Logistic regression analysis was used to evaluate the risk factors related to PHLF. The Kaplan-Meier method was used to calculate the PHLF rate and 30-day survival after surgery.

Results: A total of 885 patients with complete data were finally included in analysis, 311 of them with elevated serum PCT (≥1 ng/ml). Results of the logistic regression analysis suggested a significant association between PCT and PHLF [HR, 95%CI; 3.801 (1.825, 7.917), p < 0.001]. Other significant risk factors for PHLF included portal hypertension, portal blocking time (>30 min) and blood transfusion (>200 ml). Kaplan-Meier analysis also suggested a higher PHLF rate in elevated PCT patients [9.0% (95% CI, 7.3 to 12.8 VS. 1.9% (95% CI, 1.1–4.3)); p < 0.001]. For secondary outcomes, elevated PCT was also highly associated with postoperative sepsis, ICU admission, 30-day mortality and 3-month mortality.

Conclusion: Elevated procalcitonin level in patients after hepatectomy is related to higher PHLF rate, with lower 30-day survival and poor short-term postoperative outcomes.

C-reactive protein but not procalcitonin may predict antibiotic response and outcome in infections following major abdominal surgery

We aimed to evaluate the usefulness of C-reactive protein (CRP) and procalcitonin (PCT) as markers of infection, sepsis and as predictors of antibiotic response after non-emergency major abdominal surgery. We enrolled, from June 2015 to June 2019, all patients who underwent surgery due to abdominal infection (peritoneal abscess, peritonitis) or having sepsis episode after surgical procedures (i.e. hepatectomy, bowel perforation, pancreaticoduodenectomy (PD), segmental resection of the duodenum (SRD) or biliary reconstruction in a Tertiary Care Hospital. Serum CRP (cut-off value < 5 mg/L) and PCT (cut-off value < 0.1mcg/L) were measured in the day when fever was present or within 24 h after abdominal surgery. Both markers were assessed every 48 h to follow-up antibiotic response and disease evolution up to disease resolution. We enrolled a total of 260 patients underwent non-emergency major abdominal surgery and being infected or developing infection after surgical procedure with one or more microbes (55% mixed Gram-negative infection including Klebsiella KPC, 35% Gram-positive infection, 10% with Candida infection), 58% of patients had ICU admission for at least 96 h, 42% of patients had fast track ICU (48 h). In our group of patients, we found that PCT had a trend to increase after surgical procedure; particularly, those undergoing liver surgery had higher PCT than those underwent different abdominal surgery (U Mann–Whitney p < 0.05). CRP rapidly increase after surgery in those developing infection and showed a statistical significant decrease within 48 h in those subject being responsive to antibiotic treatment and having a clinical response within 10 days independently form the pathogens (bacterial or fungal). Further we found that those having CRP higher than 250 mg/L had a reduced percentage of success treatment at 10 days compared to those < 250 mg/mL (U Mann–Whitney p < 0.05). PCT did not show any variation according to treatment response. CRP in our cohort seems to be a useful marker to predict antibiotic response in those undergoing non-emergency abdominal surgery, while PCT seem to be increased in those having major liver surgery, probably due to hepatic production of cytokines.

Procalcitonin for individualizing antibiotic treatment: an update with a focus on COVID-19

Procalcitonin (PCT) is useful for differentiating between viral and bacterial infections and for reducing the unnecessary use of antibiotics. As the rise of antimicrobial resistance reaches “alarming” levels according to the World Health Organization, the importance of using biomarkers, such as PCT to limit unnecessary antibiotic exposure has further increased. Randomized trials in patients with respiratory tract infections have shown that PCT has prognostic implications and its use, embedded in stewardship protocols, leads to reductions in the use of antibiotics in different clinical settings without compromising clinical outcomes. However, available data are heterogeneous and recent trials found no significant benefit. Still, from these trials, we have learned several key considerations for the optimal use of PCT, which depend on the clinical setting, severity of presentation, and pretest probability for bacterial infection. For patients with respiratory infections and sepsis, PCT can be used to determine whether to initiate antimicrobial therapy in low-risk settings and, together with clinical data, whether to discontinue antimicrobial therapy in certain high-risk settings. There is also increasing evidence regarding PCT-guided therapy in patients with coronavirus disease 2019 (COVID-19). This review provides an up-to-date overview of the use of PCT in different clinical settings and diseases, including a discussion about its potential to improve the care of patients with COVID-19.

Serial assessment of inflammatory parameters for prediction of septic complications following surgery for colorectal endometriosis : A descriptive, retrospective study

Purpose

To assess whether C‑reactive protein (CRP), white blood cell count (WBC) and body temperature changes are suitable parameters for the early detection of septic complications following resection of colorectal deep endometriosis (DE).

Methods

Retrospective data analysis of CRP, WBC and body temperature courses following colorectal surgery for DE at a tertiary referral center for endometriosis.

Results

Out of 183 surgeries performed, 10 major surgical complications were observed, including 4 anastomotic leakages (AL 2%) and 2 rectovaginal fistulae (RVF 1%). In the presence of a lower gastrointestinal tract (GIT)-related septic complication or abdominal wall abscess, serum CRP levels were increased starting at postoperative day 2–3. A cut-off value of 10 mg/dl on day 4 for prediction of early septic complications could be verified (area under the curve 0.94, obtained by receiver operating characteristics analysis, sensitivity 88%, specificity 90%, positive predictive value 32%, negative predictive value 99%). Additionally, most patients with early septic complications exhibited increased WBC levels starting mainly from day 3–4; however, increased inflammatory parameters could not be observed in one patient with an RVF. Body temperature did not prove useful for early discrimination between uncomplicated cases and those with early septic complications.

Conclusion

Relevant elevations of serum CRP and WBC levels were demonstrated in patients with early septic complications following surgery for colorectal DE starting at postoperative day 2–4. The cut-off value of 10 mg/dl for CRP levels may serve as an early predictor for lower GIT-related septic complications but should be used with caution in women with suspected RVF development.

Supplementary Information

The online version of this article (10.1007/s00508-021-01916-w) contains supplementary material, which is available to authorized users.

Plasma procalcitonin may be an early predictor of liver injury in acetaminophen poisoning: A prospective cohort study

Background and Aims

Acetaminophen is a common cause of poisoning and liver injury worldwide; however, patient stratification is suboptimal. We aimed to assess the contribution of admission plasma procalcitonin concentration (PCT) to better identify acetaminophen‐poisoned patients likely to develop liver injury.

Methods

We conducted a prospective observational cohort study including all acetaminophen‐poisoned patients requiring N‐acetylcysteine admitted in a toxicological intensive care unit between 2012 and 2017. Multivariate analysis was performed using a Cox regression model to investigate factors associated with liver injury, defined as an increase in alanine aminotransferase (ALT) >100 IU/L.

Results

One hundred seventeen patients (age, 32 years (21–53), median [25th–75th percentiles]) were included after self‐ingesting 16 g (9–30) acetaminophen and received N‐acetylcysteine infusion administered within a median 6 h‐delay (4–12) from exposure. Co‐ingestions were reported in 77% of patients. Rumack–Matthew nomogram was non‐interpretable in 47% cases. Liver injury occurred in 38 patients (32%) with a median peak ALT of 2020 IU/L (577–4248). In liver injury patients, admission PCT was significantly increased in comparison to patients without liver injury (21.5 ng/ml (3.2–44.9) versus 0.1 ng/ml (0–0.4), respectively, p < 0.01). The increase in PCT preceded the increase in ALT by 33 h (10–74). In a multivariate analysis, PCT > 1 ng/ml was significantly associated with liver injury (hazard ratio, 7.2 [95% confidence interval, 2.3–22.6; p < 0.001]). PCT (area under the receiver‐operating characteristics curve, 0.91 [95%CI: 0.84–0.97]) predicted liver injury with sensitivity, specificity, negative, and positive predictive values of 0.92, 0.84, 0.96, and 0.73, respectively.

Conclusion

PCT on admission is associated with liver injury in acetaminophen poisoning. PCT might be used as a predictive tool of liver injury to improve clinical decision‐making.

Diagnostic Accuracy of Procalcitonin and C-reactive Protein Is Insufficient to Predict Proven Infection: A Retrospective Cohort Study in Critically Ill Patients Fulfilling the Sepsis-3 Criteria

BACKGROUND

New Sepsis-3 definitions facilitate early recognition of patients with sepsis. In this study we investigated whether a single initial determination of procalcitonin (PCT) or C-reactive protein (CRP) in plasma can predict proven sepsis in Sepsis-3 criteria-positive critically ill patients. We also investigated whether a decline in serial PCT or CRP can predict outcome in 28-day mortality.

METHODS

Patients, ≥18 years of age, at the intensive care unit with a suspected infection, a Sequential Organ Failure Assessment (SOFA) score of ≥2 points, and an index test PCT and CRP at admission were selected from a prospectively collected cohort. PCT and CRP were studied retrospectively with the Mann-Whitney U-test and ROC analysis.

RESULTS

In total, 157 patients were selected; 63 of the 157 had proven sepsis, and sepsis could not be detected in 94 of the 157. Neither a single PCT nor CRP at admission was able to discriminate proven sepsis from nonproven sepsis (PCT, 1.8 μg/L and 1.5 μg/L, respectively, P = 0.25; CRP, 198 mg/L and 186 mg/L, respectively, P = 0.53). Area under the curve for both PCT and CRP for detecting proven sepsis was low (0.55 and 0.53). Furthermore, neither a decline from baseline to day 5 PCT nor CRP could predict 28-day mortality (PCT, 50% vs 46%, P = 0.83; CRP, 30% vs 40%, P = 0.51).

CONCLUSION

PCT and CRP at admission were not able to discern patients with proven sepsis in Sepsis-3 criteria-positive critically ill patients. A decline of PCT and CRP in 5 days was not able to predict 28-day mortality.

Procalcitonin kinetics early after severe burn injury and its value in diagnosis of sepsis

PURPOSE

To investigate the clinical significance of procalcitonin (PCT) kinetics early after burn and the perioperative period, and to assess its diagnostic performance for sepsis in major burn patients.

METHODS

This retrospective study on major burn patents (≥40% total body surface area) admitted from 2014 to 2019 was conducted in Southwest Hospital, Chongqing, China. A total of 321 patients were included. The kinetics of PCT was analyzed during the 1st week after burn, the perioperative period, and at the onset of clinical suspected sepsis.

RESULTS

Serum PCT concentration rose immediately after burn injury. Factors associated with increased PCT level in the 1st week after burn include greater burn area (>70% TBSA) and lower age (≤14 years). Correlations between PCT kinetics after burn and the risk of early development of sepsis and mortality were observed. At the onset of sepsis, serum PCT increased significantly compared to its basal level in the 48 h before diagnosis. The area under the receiver operating characteristics curve of PCT concentration and its kinetic changes was 0.788 and 0.826, respectively. PCT kinetics showed better accuracy than PCT concentration in discrimination of Gram-positive sepsis. The optimal diagnostic thresholds for PCT concentration and its kinetics were 1.41 ng/mL, and a 1.34-fold elevation compared to the baseline level.

CONCLUSIONS

PCT kinetics in the early stage after burn was a prognostic factor for sepsis and mortality among major burn patients. Serum PCT levels could be a diagnostic biomarker for sepsis in major burn patients.

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.

Expression of Pancreatic Stone Protein is Unaffected by Trauma and Subsequent Surgery in Burn Patients

BACKGROUND

Altered levels of pro-inflammatory markers secondary to trauma or surgery present a major problem to physicians in being prone to interfere with the clinical identification of infectious events.

METHODS

Patients admitted to Zurich Burn Center between May 2015 and October 2018 with burns ≥10% total body surface area (TBSA) and without infection. Longitudinal analysis of the time course of PSP and routine inflammatory biomarkers [procalcitonin (PCT), C-reactive protein (CRP) and white blood cells (WBC)] over two days after (a) trauma with initial debridement and (b) subsequent burn surgeries was performed. The influence of TBSA, abbreviated burn severity index (ABSI), age and length of operation was investigated using a linear mixed effect regression model.

RESULTS

Sixty-six patients (15 female) were included with a mean age of 45.5 ± 18.3 years, median TBSA of 22% (IQR 17) and mean ABSI score 6.8 ± 2.7. PSP was the only biomarker that showed no association with any of the baseline characteristics. Additionally, PSP serum levels did not change over time neither after the burn trauma (p = 0.832) nor after secondary procedures (p = 0.113), while PCT levels increased significantly after the trauma (p < 0.001). Similarly, CRP serum levels were elevated significantly after both trauma and surgery (p < 0.001), whereas WBC values demonstrated a significant decline after the trauma (p < 0.001).

CONCLUSION

Established biomarkers (WBC, CRP and PCT) demonstrate decisive alterations after tissue destruction caused by burn injuries and subsequent surgical interventions. The robustness of PSP serum levels toward these inflammatory insults is a quality criterion for an upcoming sepsis biomarker.

Continuous elevation of procalcitonin in cirrhosis combined with hepatic carcinoma: a case report

BACKGROUND

Serum levels of procalcitonin (PCT) are considered a useful biomarker for the diagnosis of bacterial infection or inflammation. There are few reports of high PCT levels in end-stage liver disease regardless of bacterial infection. Here, we present a case of extremely high PCT levels (> 100 ng/mL) in a patient with severe cirrhosis combined with hepatic carcinoma.

CASE PRESENTATION

A 65-year-old man developed end-stage cirrhosis with hepatic carcinoma. Radiographic imaging showed a massive hepatocellular carcinoma with multiple loci lack of indications of resection. Hence, transcatheter hepatic arterial chemoembolization was performed three times over a period of 4 months. Before and after interventional therapies, the biochemistry laboratory results were only slightly abnormal except for persistently high PCT concentrations (> 100 ng/mL), irrespective of the evidence for bacterial infection or sepsis.

CONCLUSIONS

This case suggests that continuously high levels of PCT (> 100 ng/mL) may be present in advanced liver disease, particularly in complex situations such as decompensated cirrhosis and liver cancer, in the absence of severe infection or sepsis. This knowledge could expand the significance of PCT in liver disease.

Perioperative Procalcitonin in Predicting Infection in Children Undergoing Surgical Procedures

BACKGROUND

Procalcitonin (PCT) is a biomarker of bacterial infections with more sensitivity and specificity than commonly used inflammatory markers. PCT can be particularly helpful in the postsurgical population where the surgery itself often leads to noninfectious inflammation. We aimed to examine the utility of perioperative profiles of PCT in predicting infection in two pediatric surgical populations.

METHODS

We conducted a prospective observational study of perioperative PCT in children undergoing cardiac or neurosurgery. Consenting patients with no preoperative infection or immune deficiency were enrolled. We measured plasma PCT levels within 24 h preprocedure and 24-48 h postprocedure. Demographic, clinical, and laboratory data were collected from the medical records including clinical suspicion and confirmed infections. Perioperative PCT changes and their associations with these data are reported.

RESULTS

We enrolled 26 neuro and 15 cardiac surgery patients. There was postoperative clinical suspicion of infection in 3 neuro and 5 cardiac patients, and 1 neuro and 2 cardiac patients had subsequently confirmed infections. Cardiac patients had higher overall perioperative PCT increase than neuro cohort (P = 0.006). Neuro patient with infection had higher perioperative change in PCT (0.5 to 1.4 ng/mL) than noninfected neurosurgery patients. Cardiac patients with confirmed infections had higher postoperative levels which exceeded the previously described infection threshold of 2 ng/mL.

CONCLUSIONS

PCT is a useful early biomarker of postoperative infection in pediatric patients undergoing cardiac and neurosurgery. Patients who underwent cardiac surgery have significantly higher perioperative PCT rise than patients who underwent neurosurgery, and all patients with subsequently confirmed infections had at least 2-fold perioperative PCT increase.

Procalcitonin in the context of delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage

OBJECTIVE

Aneurysmal subarachnoid hemorrhage (aSAH) initiates a deleterious cascade activating multiple inflammatory processes, which can contribute to delayed cerebral ischemia (DCI). Procalcitonin (PCT) is an established marker for sepsis treatment monitoring, and its time course in the context of DCI after aSAH remains unclear. The aim of this trial was to assess the predictive and confirmative value of PCT levels in the context of DCI.

METHODS

All patients admitted to the authors' institution with aSAH between 2014 and 2018 were prospectively screened for eligibility. Daily PCT levels were recorded alongside relevant aSAH characteristics. The predictive and confirmative values of PCT levels were assessed using a receiver operating characteristic and area under the curve (AUC) analysis. The course of PCT levels around the DCI event was evaluated in an infection-free subgroup of patients.

RESULTS

A total of 132 patients with aSAH were included. Early PCT levels (first 3 days post-aSAH) had a low predictive value for the development of DCI (AUC 0.661, standard error [SE] 0.050; p = 0.003) and unfavorable long-term outcome (i.e., Glasgow Outcome Scale-Extended scores 1-4; AUC 0.674, SE 0.054; p = 0.003). In a subgroup analysis of infection-free patients (n = 72), PCT levels were higher in patients developing DCI (p = 0.001) and DCI-related cerebral infarction (p = 0.002). PCT concentrations increased gradually after DCI and decreased with successful intervention. In refractory cases progressing to cerebral infarction, PCT levels showed a secondary increase.

CONCLUSIONS

Early higher PCT levels were associated with the later development of DCI and unfavorable outcome. Analysis of PCT beyond the first couple of days after hemorrhage is hampered by nosocomial infections. In infection-free patients, however, PCT levels rise during DCI and an additional increase develops in patients developing cerebral infarction. Clinical trial registration no.: NCT02142166 (clinicaltrials.gov).

Procalcitonin Measurement in Pleural Fluid to Predict Infectious Complications of the Chest Post Lung Resection

AIM

Procalcitonin (PCT) is variably used in clinical practice to identify infectious processes. This study investigated whether PCT level in pleural fluids could predict the infectious complications in the chests of patients undergoing lobectomy.

PATIENTS AND METHODS

Thirty-four patients undergoing lobectomy for lung cancer were enrolled. PCT levels were measured in serum (S-PCT) and pleural effusion (PF-PCT) on consecutive postoperative days (PODs). The patients were grouped according to the development of chest infectious complications (atelectasis/pneumonia, postoperative infected pleural effusion/empyema/infected space, prolonged air leak >5 days with evidence of infection, lung torsion, and lung infarction). Multivariate analysis was performed to identify if S-PCT or PF-PCT and on which PODs were predictive of chest infectious complications. Receiver operating characteristic (ROC) analysis was further performed to identify cutoff values.

RESULTS

Eleven patients experienced infectious complications within a median of 4 days (range 3-5 days) postoperatively. S-PCT and PF-PCT in non-complicated patients did not significantly increase postoperatively and followed a decreasing course. Only PF-PCT was significantly increased in complicated patients from POD1; the level peaked on POD4, as did that of S-PCT. PF-PCT on POD2 and 3 and S-PCT on POD3 independently predicted chest infectious complications. ROC analysis showed that PF-PCT > 0.88 ng/dL on POD2 was the most sensitive predictor of such complications (area under the ROC curve [AUC]: 0.979, sensitivity 85%/specificity 91%, p < .001) compared to S-PCT POD3 and PF-PCT POD3.

CONCLUSION

Compared to PCT concentrations in serum, those in pleural fluids were more sensitive and predicted chest infectious complications earlier in patients undergoing lobectomy.

Prognostic Value of Serially Estimated Serum Procalcitonin Levels in Traumatic Brain Injury Patients With or Without Extra Cranial Injury on Early In-hospital Mortality: A Longitudinal Observational Study

Background

Traumatic brain injury (TBI) is associated with majority of trauma deaths, and objective tools are required to understand the severity of injury. The application of a biomarker like procalcitonin (PCT) in TBI may allow for assessment of severity and thus aid in prognostication and correlation with mortality and outcome.

Aims

The primary objective is to determine the correlation between PCT concentrations with TBI outcomes (mainly in terms of mortality) at intensive care unit (ICU)/hospital discharge. Secondary objectives are to evaluate correlation with associated extra cranial injuries and complications during hospital stay.

Methods

In total, 186 TBI patients aged > 18 years with minimum survival for at least 12 h admitted to the ICU at the level 1 trauma center were prospectively included in the study and divided into two groups: TBI with and without extra cranial injuries. All admitted patients were treated according to the standard institutional protocol. The PCT levels were obtained on admission, on day 2, and 5. Clinical, laboratory, diagnostic, and therapeutic data were also collected. Primary mortality is defined as death related to central nervous system (CNS) injury, while secondary mortality defined as death related to sepsis or extracranial cause.

Results

Median PCT levels at admission, day 2, and day 5 in TBI patients with extracranial injuries were 3.0, 0.83, and 0.69 ng/ml. In total, primary mortality was observed in 18 (9.7%) patients, while secondary causes were attributable in 20 (12.3%) patients. Regression analysis for primarily CNS cause of mortality showed PCT cutoff level at admission more than 5.5 ng/ml carried sensitivity and specificity of 75%, but for secondary cause (sepsis) of mortality, PCT cutoff values on day 2 > 1.15 ng/ml were derived significant with sensitivity of 70% and specificity of 66%. No significant association of parameters like length of ICU stay, Glasgow outcome scale (GOS), and primary/secondary mortality with the presence of extracranial injuries in TBI patients as compared with TBI alone was noted.

Conclusion

This observational study demonstrates the poor correlation between PCT concentrations with outcome at days 1, 2, and 5 post-injury. The predicted relationship between PCT levels and outcome was not confirmed, and that these results do not support the prognostic utility of PCT biomarker in this population for outcome (mortality) assessment in TBI patients with or without extracranial injuries.

Plasma Procalcitonin Is Useful for Predicting the Severity of Acute Cholecystitis

Background

Acute cholecystitis is a common complication of cholelithiasis. Delayed diagnosis may constitute morbidity and mortality; therefore, early diagnosis and determining the severity of acute cholecystitis are crucial.

Objectives

This study aimed to determine the validity of blood procalcitonin (PCT) levels in assessing the severity of acute cholecystitis.

Methods

The Emergency Department (ED) patients diagnosed as acute cholecystitis were included in the study. Patients were allocated into three severity grades according to the Tokyo Guidelines 2013. PCT level was measured after the clinical and radiological diagnosis of acute cholecystitis in the ED.

Results

Ninety-five patients diagnosed with acute cholecystitis, among them 48 of were male. Forty patients (42.1%) were allocated to grade 1, 19 (20%) to grade 2, and 36 (37.9%) to grade 3. The median values of PCT were 0.104 ng/ml, 0.353 ng/ml, and 1.466 ng/ml for grade 1, 2, and 3 patients, respectively (p < 0.001).

Conclusion

Blood procalcitonin levels can be used to determine the severity of acute cholecystitis effectively.

Procalcitonin Kinetics After Heart Transplantation and as a Marker of Infection in Early Postoperative Course

INTRODUCTION

Procalcitonin (PCT) is a biomarker of systemic infection. Specificity of PCT is decreased because PCT is also elevated after heart transplantation (HTx). There is no established normal range of serum PCT concentrations after HTx yet. Our aim was to determine the course of PCT concentrations in patients after HTx in the early postoperative period, if we can discriminate postoperative increase in values from infectious complications.

RESULTS

Of 39 patients we diagnosed infection in 11. These patients develop acute kidney injury significantly more often than in control group (group C) (5 in infection group [group I] and 2 in group C, P < .05), and 1 patient died within 30 days in group C. Seven patients developed primary graft dysfunction (3/4 + ECMO [extracorporeal membrane oxygenation], respectively, group I/group C) and 2 neurologic disorders in group I. Reoperation due to bleeding was 3 in each group. During the 14 days after HTx, serum PCT concentrations increased with maximum on the second postoperative day (group C: 30.6 ± 15.3 ng/mL; group I: 24.9 ± 44.3 ng/mL). Normal values for PCT were reached on day 8 in group C and 11 in group I. Mean PCT levels were similar: 8.7 ± 5.7 ng/mL vs 11.9 ± 13.1 ng/mL in group I vs group C, respectively. Patients in group I stayed longer in the intensive care unit.

CONCLUSIONS

Despite increase in serum concentration of PCT in early postoperative course after HTx there is no marker of infection. Trends in PCT serum concentration may be a valuable tool in diagnosis of infection in patients after HTx, but further investigation is needed.

Presepsin values as markers of severity of sepsis

OBJECTIVES

Biomarkers are widely used for rapid diagnosis of sepsis. This study evaluated the diagnostic accuracy of presepsin, procalcitonin (PCT), and C-reactive protein (CRP) in differentiating sepsis severity as well as their association with Sepsis-related Organ Failure Assessment (SOFA) score.

METHODS

One hundred septic patients from two university clinical centers were enrolled in the study during two time periods. New Sepsis-3 definitions were used for sepsis stratification. Biomarkers and SOFA score were evaluated four times during the illness. A sandwich ELISA kit was used for presepsin measurement. Generalized linear mixed effects model was used to test the changes in biomarkers concentrations and SOFA score values during the illness and to estimate the differences between severity groups. Multivariate analysis was used to test the association of biomarkers with SOFA score.

RESULTS

Presepsin concentrations were significantly higher on admission in patients with septic shock (n = 34) compared to patients with sepsis (n = 66), mean ± SD: 128.5 ± 47.6 ng/mL vs. 88.6 ± 65.6 ng/mL, respectively (p < 0.001). The same was not observed for PCT and CRP; their concentrations did not differ significantly between severity groups. A strong correlation of presepsin with SOFA score was also found (p < 0.0001).

CONCLUSIONS

Presepsin had a good diagnostic ability to differentiate septic shock from sepsis in the study groups. PCT and CRP failed in differentiating sepsis severity.

Correlation of procalcitonin to positive blood culture results in a sample of South African trauma ICU patients between 2016 and 2017

PURPOSE

This study sought to investigate the screening accuracy of procalcitonin (PCT) for bacteremia, as defined by a positive blood culture, in a South African trauma ICU.

METHODS

This was a retrospective chart review study involving 149 patients who were admitted to the ICU of a level-1 trauma center in South Africa between 2016 and 2017. Median PCT levels in patients with and without positive blood cultures were compared. The screening accuracy of PCT for a positive blood culture was summarized as sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). Two PCT cut-points were investigated: a general cut-point in the South African context (> 2.0 ng/mL), and a trauma ICU-specific cut-point (prioritizing specificity while optimizing sensitivity) which was determined from a receiver-operator-characteristic curve.

RESULTS

Bacteremic patients had higher median PCT levels when compared with non-bacteremic patients (30.5 ng/mL versus 6.6 ng/mL, p = 0.002). The sensitivity, specificity, PPV, and NPV of PCT > 2.0 ng/mL was 86% (95% confidence interval-CI 71-94%), 29% (CI 22-38%), 28% (CI 20-37%), and 87% (CI 73-94%), respectively. The unit-specific cut-point was PCT > 31.0 ng/mL, which had a sensitivity, specificity, PPV, and NPV of 50% (CI 34-66%), 80% (CI 71-86%), 44% (CI 30-59%), and 83% (CI 75-89%), respectively. Unlike PCT > 2.0 ng/mL, PCT > 31.0 ng/mL demonstrated fair-to-good test specificity in a sub-analysis of patients who underwent recent surgery.

CONCLUSIONS

Increased PCT levels were associated with bacteremia in this study. PCT > 31.0 ng/mL may be used to rule in suspected bacteremia in this trauma ICU setting.

How can biomarkers be used to differentiate between infection and non-infectious causes of inflammation?

Diagnosis of sepsis is based on recognition of systemic inflammation and organ failure in the context of an inciting infection. Since none of the diagnostic criteria are specific to sepsis, it is easy to confound sepsis with noninfectious causes of systemic inflammation, including pancreatitis, cardiac ischemia, bowel perforation, vasculitis, and pulmonary embolism amongst others. Two widely used biomarkers, C-reactive protein and procalcitonin, have proven promising in sepsis diagnosis. Each has found varying success in the clinical context, with some centers relying heavily on these markers and others eschewing their use almost entirely. In this chapter, we present the evidence for their use in the diagnosis of sepsis and management of antibiotic therapy in the intensive care unit context.

The prognostic value of serum procalcitonin measurements in critically injured patients: a systematic review

Background

Major trauma is associated with high incidence of septic complications and multiple organ dysfunction (MOD), which markedly influence the outcome of injured patients. Early identification of patients at risk of developing posttraumatic complications is crucial to provide early treatment and improve outcomes. We sought to evaluate the prognostic value of serum procalcitonin (PCT) levels after trauma as related to severity of injury, sepsis, organ dysfunction, and mortality.

Methods

We searched PubMed, MEDLINE, EMBASE, the Cochrane Database, and references of included articles. Two investigators independently identified eligible studies and extracted data. We included original studies that assessed the prognostic value of serum PCT levels in predicting severity of injury, sepsis, organ dysfunction, and mortality among critically injured adult patients.

Results

Among 2015 citations, 19 studies (17 prospective; 2 retrospective) met inclusion criteria. Methodological quality of included studies was moderate. All studies showed a strong correlation between initial PCT levels and Injury Severity Score (ISS). Twelve out of 16 studies demonstrated significant elevation of initial PCT levels in patients who later developed sepsis after trauma. PCT level appeared a strong predictor of MOD in seven out of nine studies. While two studies did not show association between PCT levels and mortality, four studies demonstrated significant elevation of PCT levels in non-survivors versus survivors. One study reported that the PCT level of ≥ 5 ng/mL was associated with significantly increased mortality (OR 3.65; 95% CI 1.03–12.9; p = 0.04).

Conclusion

PCT appears promising as a surrogate biomarker for trauma. Initial peak PCT level may be used as an early predictor of sepsis, MOD, and mortality in trauma population.

Urinary volatile organic compound markers and colorectal anastomotic leakage

AIM

Inflammatory markers such as serum C-reactive protein (CRP) are used as routine markers to detect anastomotic leakage following colorectal surgery. However, CRP is characterized by a relatively low predictive value, emphasizing the need for the development of novel diagnostic approaches. Volatile organic compounds (VOCs) are gaseous metabolic products deriving from all conceivable bodily excrements and reflect (alterations in) the patient's physical status. Therefore, VOCs are increasingly considered as potential non-invasive diagnostic biomarkers. The aim of this study was to assess the diagnostic accuracy of urinary VOCs for colorectal anastomotic leakage.

METHODS

In this explorative multicentre study, urinary VOC profiles of 22 patients with confirmed anastomotic leakage and 27 uneventful control patients following colorectal surgery were analysed by field asymmetric ion mobility spectrometry (FAIMS).

RESULTS

Urinary VOCs of patients with anastomotic leakage could be distinguished from those of control patients with high accuracy: area under the receiver operating characteristics curve 0.91 (95% CI 0.81-1.00, P < 0.001), sensitivity 86% and specificity 93%. Serum CRP was significantly increased in patients with a confirmed anastomotic leak but with lower diagnostic accuracy compared to VOC analysis (area under the receiver operating characteristics curve 0.82, 95% CI 0.68-0.95, P < 0.001). Combining VOCs and CRP did not result in a significant improvement of the diagnostic performance compared to VOCs alone.

CONCLUSION

Analysis by FAIMS allowed for discrimination between urinary VOC profiles of patients with a confirmed anastomotic leak and control patients following colorectal surgery. A superior accuracy compared to CRP and apparently high specificity was observed, underlining the potential as a non-invasive biomarker for the detection of colorectal anastomotic leakage.

Hypophosphatemia as a Predictor of Organ-Specific Complications Following Gastrointestinal Surgery: Analysis of 8034 Patients

BACKGROUND

Organ-specific complications (OSC) remain serious potential sequela of gastrointestinal surgery. Hypophosphatemia correlates with poor outcomes and may be a harbinger of OSC after gastrointestinal surgery. Our goal was to describe and evaluate the relationship between postoperative phosphate levels and OSC.

METHODS

Consecutive patients who underwent pancreatic, colorectal, or gastric resections were analyzed. OSC were defined as those resulting from the failure of at least one anastomosis performed during the primary resection, manifesting as an anastomotic leak, fistula, and/or intra-abdominal abscess. Postoperative serum phosphate levels and other recognized OSC risk factors were compared among patients who did and did not develop OSC.

RESULTS

A total of 8034 patients who underwent pancreatic (n = 397), colorectal (n = 5808), or gastric (n = 1829) resections were included in the study. In each resection group, the majority of patients experienced hypophosphatemia postresection with the nadir on postoperative day (POD) 2, and the subgroups that developed OSC exhibited lower phosphate levels on POD3-7. On multivariate analysis, lower phosphate level on POD3 remained significantly associated with OSC following pancreatic resection [median (interquartile range) mmol/L, 0.65 (0.53-0.76) vs. 0.71 (0.61-0.84), p = 0.045] and colorectal resection [0.71 (0.61-0.87) vs. 0.77 (0.65-0.94), p = 0.006], and lower phosphate level on POD4 remained associated with OSC following gastric resection [0.87 (0.74-1.03) vs. 0.96 (0.81-1.13), p = 0.049].

CONCLUSION

This study identified a consistent trajectory of serum phosphate levels following 3 different gastrointestinal operations and association between early postoperative phosphate levels and OSC. Persistent lower phosphate levels should raise the level of concern for evolving postoperative leak and may lead to earlier radiographic evaluation and treatment.

The Confounding Effects of Non-cardiac Pathologies on the Interpretation of Cardiac Biomarkers

PURPOSE OF REVIEW

Cardiac biomarkers play important roles in routine evaluation of cardiac patients. But while these biomarkers can be extremely valuable, none of them should ever be used by themselves-without adding the clinical context. This paper explores the non-cardiac pathologies that can be seen with the cardiac biomarkers most commonly used.

RECENT FINDINGS

High-sensitivity troponin assay gained FDA approval for use in the USA, and studies demonstrated its diagnostic utility can be extended to patients with renal impairment. Gender-specific cut points may be utilized for high-sensitivity troponin assays. In the realm of the natriuretic peptides, studies demonstrated states of natriuretic peptide deficiency in obesity and in subjects of African-American race. Regardless, BNP and NT-proBNP both retained prognostic utilities across a variety of comorbid conditions. We are rapidly gaining clinical evidence with use of soluble ST2 and procalcitonin levels in management of cardiac disease states. In order to get the most utility from their measurement, one must be aware of non-cardiac pathologies that may affect the levels of biomarkers as although many of these are actually true values, they may not represent the disease we are trying to delineate. A few take-home points are as follows: 1. A biomarker value should never be used without clinical context 2. Serial sampling of biomarkers is often helpful 3. Panels of biomarkers may be valuable.

Procalcitonin-Guided Treatment on Duration of Antibiotic Therapy and Cost in Septic Patients (PRODA): a Multi-Center Randomized Controlled Trial

BACKGROUND

The objective of this study was to establish the efficacy and safety of procalcitonin (PCT)-guided antibiotic discontinuation in critically ill patients with sepsis in a country with a high prevalence of antimicrobial resistance and a national health insurance system.

METHODS

In a multi-center randomized controlled trial, patients were randomly assigned to a PCT group (stopping antibiotics based on a predefined cut-off range of PCT) or a control group. The primary end-point was antibiotic duration. We also performed a cost-minimization analysis of PCT-guided antibiotic discontinuation.

RESULTS

The two groups (23 in the PCT group and 29 in the control group) had similar demographic and clinical characteristics except for need for renal replacement therapy on ICU admission (46% vs. 14%; P = 0.010). In the per-protocol analysis, the median duration of antibiotic treatment for sepsis was 4 days shorter in the PCT group than the control group (8 days; interquartile range [IQR], 6-10 days vs. 14 days; IQR, 12-21 days; P = 0.001). However, main secondary outcomes, such as clinical cure, 28-day mortality, hospital mortality, and ICU and hospital stays were not different between the two groups. In cost evaluation, PCT-guided therapy decreased antibiotic costs by USD 30 (USD 241 in the PCT group vs. USD 270 in the control group). The results of the intention-to-treat analysis were similar to those obtained for the per-protocol analysis.

CONCLUSION

PCT-guided antibiotic discontinuation in critically ill patients with sepsis could reduce the duration of antibiotic use and its costs with no apparent adverse outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02202941.

ATP in red blood cells as biomarker for sepsis in humans

Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to an infection. Due to the lack of causative immune treatment, mortality of sepsis remains at a high level and represents one of the main disease burdens globally. Adenosine 5' triphosphate (ATP) levels in red blood cells (RBC) are modulated by various factors during sepsis, including a decrease in ATP production, an increase in ATP catabolism and alterations in ATP release. Therefore, we hypothesize that intracellular ATP levels in RBC can serve as potential biomarker for sepsis and support sepsis diagnosis. This will facilitate early treatment and could improve the outcome of this serious condition.

Prognostic Value of Serum Procalcitonin level for the Diagnosis of Bacterial Infections in Critically-ill Patients

Background

Procalcitonin (PCT) is a diagnostic biomarker for bacterial infections in critically-ill patients. However, the cut-off value of PCT for the diagnosis of bacterial infections is unclear and unreliable. This study aimed to determine the optimal cut-off value of PCT for the diagnosis of bacterial infections in critically-ill patients.

Materials and Methods

We conducted a retrospective study involving 311 adult patients who had been admitted to the medical or surgical intensive care unit for more than 24 hours from 2013 to 2015. At least one blood test for PCT level was performed for all patients within the first 24 hours of suspecting an infection.

Results

One hundred and fifty-seven patients had bacterial infections, while 154 did not. Patients with bacterial infections had a significantly higher median PCT level than those without bacterial infections (1.90 ng/mL vs. 0.16 ng/mL, P <0.001). The area under the receiver operating characteristic curve of PCT for discriminating between bacterial and non-bacterial infections was 0.874 (95% confidence interval: 0.834, 0.914; P <0.001). The optimal cut-off value of PCT for differentiating between fevers due to bacterial infections from those due to non-bacterial infections was 0.5 ng/mL, with a sensitivity of 84.7%, specificity of 79.9%, positive predictive value of 81.1%, and negative predictive value of 83.7%.

Conclusion

PCT was found to be an accurate biomarker for the diagnosis of bacterial infections among patients admitted to medical and surgical intensive care units. The optimal cut-off value of PCT for the diagnosis of bacterial infections was 0.5 ng/mL.

The use of procalcitonin in the determination of severity of sepsis, patient outcomes and infection characteristics

Objective

The primary objective of this study was to determine the correlation between procalcitonin values and illness severity by evaluating the degree of end organ dysfunction using the Sequential Organ Failure Assessment score, length of stay and the severity of sepsis (sepsis alone vs. septic shock), The hypothesis that procalcitonin values would be higher in sicker patients was formulated before data collection began. Secondary outcomes studied in relation to procalcitonin levels included infection characteristics such as the site of infection, microbial agent and dialysis dependent CKD.

Design

Unblinded retrospective cohort study. September 2014-December 2016.

Setting

364 patients with a diagnosis of sepsis or severe sepsis who were admitted to the general medical ward and ICU at Methodist Medical Center and Proctor Hospital in Peoria, Illinois, USA.

Results

This study demonstrates the following: Weak positive correlation between procalcitonin and SOFA score. Negligible correlation with length of stay. Higher values in patients who died than in patients who survived to discharge (p = 0.058). Sensitivity and specificity of procalcitonin for septic shock was 63 and 65% respectively. Sites typically infected by gram negative bacteria have higher procalcitonin values than sites infected by gram positive bacteria (p = 0.03). Higher procalcitonin in bacteremia than non-bacteremic infections (p = 0.004). Higher procalcitonin in dialysis-dependent CKD patients (p = 0.020).

Conclusions

Procalcitonin has a higher specificity for bacterial infections than other acute phase reactants. Although initial procalcitonin value may be helpful in the determination of illness severity, it is not always a reliable prognostic indicator and carries little significance as a standalone value. Procalcitonin values may be influenced by preexisting comorbid conditions such as chronic kidney disease, which are associated with higher procalcitonin values at baseline. Procalcitonin can provide invaluable information when viewed as one piece of a clinical puzzle, and is most powerful when the interpreting physician is aware of how values are influenced by the different clinical scenarios presented in this article.

Procalcitonin kinetics after burn injury and burn surgery in septic and non-septic patients - a retrospective observational study

BACKGROUND

Early sepsis diagnosis is crucial for the correct management of burn patients, and it clearly influences outcomes. The systemic inflammatory response triggered by burns mimics sepsis presentation and complicates early sepsis diagnosis. Biomarkers were advocated to aid the diagnosis of early sepsis. Serum procalcitonin (PCT) exhibits fair accuracy and good correlation with sepsis severity, being used in diverse clinical settings. However, few studies have evaluated perioperative changes in PCT levels in burn patients. The present study evaluated PCT kinetics during the first days after burn injury and subsequent surgical interventions to assess PCT utility in distinguishing septic from non-septic inflammatory responses.

METHODS

This study was a retrospective observational study of all burn patients admitted to the Coimbra Burns Unit (Portugal) between January 2011 and December 2014 who presented with a total burn surface area ≥ 15% and who underwent subsequent surgery. PCT kinetics were investigated a) during the first five days after burn injury and b) preoperatively during the five days after surgery in three subsets of patients, including those with no preoperative and no postoperative sepsis (NN), no preoperative but postoperative sepsis (NS), and preoperative and postoperative sepsis (SS). A total of 145 patients met the selection criteria and were included in the analysis.

RESULTS

PCT levels in the first five days after burn injury were significantly higher in patients who developed at least one sepsis episode (n = 85) compared with patients who did not develop sepsis (n = 60). PCT values > 1.00 ng/mL were clearly associated with sepsis. Study participants (n = 145) underwent a total of 283 surgical interventions. Their distribution by preoperative/postoperative sepsis status was 142 (50.2%) in NN; 62 (21.9%) in NS; and 79 (27.9%) in SS. PCT values exhibited a parallel course in the three groups that peaked on the second postoperative day and returned to preoperative levels on the third day or later. The lowest PCT values were found in NN, and the highest values were observed in SS; the NS values were intermediate.

CONCLUSIONS

PCT kinetics coupled with a clinical examination may be helpful for sepsis diagnosis during the first days after burn injury and burn surgery.

Dogma without Data: A Clinical Decision-Making Tool for Postoperative Blood Cultures

Bacteremia is a worrisome postoperative complication and blood cultures (BCx) are often nondiagnostic. We previously reported a 4 per cent overall yield of positive cultures in postoperative patients. To reduce unnecessary testing, we present a predictive model to identify patients in whom growth of pathogens is unlikely and provide a clinical decision-making guide. Retrospective analysis of nonpregnant patients ≥18 years who had BCx within 10 days postoperatively was performed. Generalized linear mixed models identified clinical predictors of high- and low-yield cultures. A clinical algorithm was created using significant predictors, and positive predictive value, negative predictive value, sensitivity, and specificity calculated. Among 1759 BCx, hypotension, maximum temperature ≥101.5 °F within 24 hours of culture, and culture collected after postoperative day (POD) two were statistically significant predictors of positive cultures. Forty nine per cent of BCx were sent ≤ POD 2, and <1 per cent of these were positive. When all three criteria were met, the probability of a positive culture increased to 17 per cent. When absent, the probability of a negative culture was 99 per cent. When applied to the initial data set, the model resulted in 85 per cent reduction of cultures with 9 per cent yield of positive cultures. Drawing BCx based on a single predictor is inadequate. Reducing the number of cultures reflexively ordered within the first two POD could significantly reduce the number of unnecessary BCx. Several clinical features identified patients most likely to have positive BCx within the first 10 POD and could reduce unnecessary BCx. This model should be validated in an independent, prospective cohort.

Serum procalcitonin concentration within 2 days postoperatively accurately predicts outcome after liver resection

Background:

Relatively high mortality and morbidity rates are reported after liver resection (LR). However, the early predictors of complications after LR are not clear. This study was performed to clarify the usefulness of procalcitonin (PCT) for the early prediction of complications after elective LR.

Methods:

This observational study included 72 consecutive patients who underwent elective LR from December 2015 to March 2017. Patients were categorized into two groups: those with and without postoperative complications (Clavien-Dindo grade ≥II). The values of postoperative inflammatory markers (white blood cell [WBC] count, C-reactive protein [CRP] and PCT) were compared between the two groups.

Results:

CRP and PCT were significantly higher in patients with than without complications; however, the WBC count showed no difference within 5 days postoperatively. The maximum area under the receiver operating characteristic curves within 2 days after LR using the WBC count, CRP and PCT were 0.608, 0.697 and 0.860, respectively, PCT had the best predictive ability in the early postoperative period. The PCT level peaked within 2 days postoperatively in 61 patients (85%). The maximum PCT level within 2 days postoperatively (PCT1−2) was significantly higher in patients with than without complications (0.52 vs. 0.19 ng/mL, p<0.001). A cutoff PCT1−2 level of 0.35 ng/mL achieved 80% sensitivity and 83% specificity. In patients without complications, there was no difference in PCT1−2 even when the surgical procedure differed (p=0.935).

Conclusions:

PCT1−2 is an early predictive marker after LR and can be similarly used regardless of the LR procedure.

Value of procalcitonin as a marker of surgical site infection following spinal surgery

AIM

To compare the value of Procalcitonin (PCT) as a marker of surgical site infection to other inflammatory markers, including C-Reactive Protein (CRP), White Cell Count (WCC) and Erythrocyte Sedimentation Rate (ESR) in patients undergoing a number of spinal procedures. This study also aims to describe the biokinetic profile of the above-named markers in patients developing surgical site infection and those remaining infection-free post-operatively.

METHODS

200 patients undergoing four routine elective spinal procedures were included for analysis. All patients had blood specimens taken at baseline, day 1, 2, 3, 4 and 5 post-operatively for analysis of PCT, CRP, ESR and WCC levels. All patients were monitored for early surgical site infection. Patients with other sources of infection in the early postoperative period were excluded.

RESULTS

Procalcitonin was the most sensitive and specific marker for the detection of surgical site infection in the immediate post-operative period with sensitivity and specificity of 100% and 95.2% respectively. Although Procalcitonin is an inflammatory marker, extent of surgical physiological insult did not alter its biokinetics as opposed to the other inflammatory markers making it a valuable marker of infection.

CONCLUSION

Procalcitonin was found to be superior to the other inflammatory markers investigated in this study as a marker for early surgical site infection in patients undergoing spinal surgery.