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.

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.

Procalcitonin in special patient populations: Guidance for antimicrobial therapy

PURPOSE

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

SUMMARY

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

CONCLUSION

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

Impact of intraoperative cytokine adsorption on outcome of patients undergoing orthotopic heart transplantation-an observational study

AIM

The aim of this study was to assess the influence of intraoperative cytokine adsorption on the perioperative vasoplegia, inflammatory response and outcome during orthotopic heart transplantation (OHT).

METHODS

Eighty-four OHT patients were separated into the cytokine adsorption (CA)-treated group or controls. Vasopressor demand, inflammatory response described by procalcitonin and C-reactive protein, and postoperative outcome were assessed performing propensity score matching.

RESULTS

In the 16 matched pairs, the median noradrenaline requirement was significantly less in the CA-treated patients than in the controls on the first and second postoperative days (0.14 vs 0.3 μg*kg^-1 *min^-1 , P = .039 and 0.06 vs 0.32 μg*kg^-1 *min^-1 , P = .047). The inflammatory responses were similar in the two groups. There was a trend toward shorter length of mechanical ventilation and intensive care unit (ICU) stay in the CA-treated group compared to the controls. No difference in adverse events was observed between the two groups. The frequency of renal replacement therapy was less in the CA‐treated patients than in the controls.

CONCLUSIONS

Intraoperative CA treatment was associated with reduced vasopressor demand with a favorable tendency in length of mechanical ventilation, ICU stay and renal replacement therapy. CA treatment was not linked to higher rates of adverse events.

Is Endocan a Diagnostic Marker for Pneumonia After Cardiac Surgery? The ENDOLUNG Study

BACKGROUND

Postoperative pneumonia is frequent after cardiac surgery and is associated with increased morbidity and mortality. We tested the hypothesis that endocan is an early biomarker for the detection of pneumonia after cardiac surgery.

METHODS

Between January and May 2016, 155 patients scheduled to undergo elective cardiac surgery with cardiopulmonary bypass were prospectively included in the study. Serum level of endocan was measured at five timepoints (preoperative, and at 6, 24, 48, and 72 hours after the end of surgery). Procalcitonin and C-reactive protein were measured at 24 and 72 hours. The preoperative and postoperative characteristics of the patients were recorded. Independent predictors of postoperative pneumonia were identified by logistic regression. Threshold values of endocan predictive of postoperative pneumonia were determined using receiver-operating characteristics curve analysis.

RESULTS

Seventeen patients (11%) had pneumonia after surgery. Endocan greater than 3.7 ng/mL before induction of anesthesia, or greater than 12.1 ng/mL at 6 hours after surgery, as well body mass index higher than 27 kg/m² and duration of surgery were independent predictors of postoperative pneumonia. At induction of anesthesia, an endocan cutoff value of 3.7 ng/mL had 65% sensitivity and 72% specificity for the prediction of postoperative pneumonia; whereas at 6 hours, with a cutoff value of 12.1 ng/mL, these values were 71% and 75%, respectively. The time saved by endocan dosage compared with clinical diagnosis of postoperative pneumonia was 96 hours.

CONCLUSIONS

This study shows that endocan is an early marker of postoperative pneumonia in patients after cardiac surgery.

Monitoring of procalcitonin but not interleukin-6 is useful for the early prediction of anastomotic leakage after colorectal surgery

BACKGROUND

Early recognition of patients who have developed anastomotic leakage (AL) after colorectal surgery is crucial for the successful treatment of this complication. The aim of this study was to assess the usefulness of the assessment of procalcitonin (PCT) and interleukin-6 (IL-6) levels in the prognosis of AL.

METHODS

This observational study included 157 patients who underwent major elective colorectal surgery. The most common indications for surgery were cancer and inflammatory bowel diseases. Serum samples were obtained directly before surgery (D0) and 1 day (D1) after surgery, and the relationships between the serum concentrations of PCT and IL-6 and development of AL were assessed.

RESULTS

In total, 10.2% of patients developed post-surgical infections due to AL. PCT levels on D1 were significantly higher in patients who developed AL [2.73 (1.40-4.62)] than in those who recovered without complications [0.2 (0.09-0.44)]. The area under the ROC curve for PCT on D1 was 0.94, 95% CI (0.89-0.98). The sensitivity and specificity of the prediction of an infection were 87% and 87%, respectively, for PCT on D1, which was higher than 1.09 ng/mL. The increase in PCT concentration between D0 and D1 was significantly higher in patients with AL (p<0.001). Patients who developed AL had higher concentrations of IL-6 on D1, but the difference was not significant (p=0.28).

CONCLUSIONS

This study confirms that surgical trauma increases serum PCT concentrations and that the concentration of PCT on D1 can predict AL after colorectal surgery. However, IL-6 is not a good early marker for developing AL.

Procalcitonin-guided diagnosis and antibiotic stewardship revisited

Several controlled clinical studies have evaluated the potential of the infection biomarker procalcitonin (PCT) to improve the diagnostic work-up of patients with bacterial infections and its influence on decisions regarding antibiotic therapy. Most research has focused on lower respiratory tract infections and critically ill sepsis patients. A clinical utility for PCT has also been found for patients with urinary tract infections, postoperative infections, meningitis, and patients with acute heart failure with possible superinfection (i.e., pneumonia). In these indications, PCT levels measured on hospital admission were found to substantially reduce the initiation of antibiotic treatment in low-risk situations (i.e., bronchitis, chronic obstructive pulmonary disease exacerbation). For more severe infections (i.e., pneumonia, sepsis), antibiotic stewardship by monitoring of PCT kinetics resulted in shorter antibiotic treatment durations with early cessation of therapy. Importantly, these strategies appear to be safe without increasing the risk for mortality, recurrent infections, or treatment failures. PCT kinetics also proved to have prognostic value correlating with disease severity (i.e., pancreatitis, abdominal infection) and resolution of illness (i.e., sepsis). Although promising findings have been published in these different types of infections, there are a number of limitations regarding PCT, including suboptimal sensitivity and/or specificity, which makes a careful interpretation of PCT in the clinical context mandatory. This narrative review aims to update clinicians on the strengths and limitations of PCT for patient management, focusing on research conducted within the last 4 years.

Procalcitonin as a biomarker of bacterial infection in pediatric patients after congenital heart surgery

Background:

Bacterial infection (BI) after congenital heart surgery (CHS) is associated with increased morbidity and is difficult to differentiate from systemic inflammatory response syndrome caused by cardiopulmonary bypass (CPB). Procalcitonin (PCT) has emerged as a reliable biomarker of BI in various populations.

Aim:

To determine the optimal PCT threshold to identify BI among children suspected of having infection following CPB.

Setting and Design:

Single-center retrospective observational study.

Materials and Methods:

Medical records of all the patients admitted between January 2013 and April 2015 were reviewed. Patients in the age range of 0-21 years of age who underwent CHS requiring CPB in whom PCT was drawn between postoperative days 0-8 due to suspicion of infection were included.

Statistical Analysis:

The Wilcoxon rank-sum test was used for nonparametric variables. The diagnostic performance of PCT was evaluated using a receiver operating characteristic (ROC) curve.

Results:

Ninety-eight patients were included. The median age was 2 months (25th and 75th interquartile of 0.1-7.5 months). Eleven patients were included in the BI group. The median PCT for the BI group (3.42 ng/mL, 25th and 75th interquartile of 2.34-5.67) was significantly higher than the median PCT for the noninfected group (0.8 ng/mL, 25th and 75th interquartile 0.38-3.39), P = 0.028. The PCT level that yielded the best compromise between the sensitivity (81.8%) and specificity (66.7%) was 2 ng/mL with an area under the ROC curve of 0.742.

Conclusion:

A PCT less than 2 ng/mL makes BI unlikely in children suspected of infection after CHS.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Can procalcitonin levels indicate the need for adjunctive therapies in sepsis?

After decades of extensive experimental and clinical research, septic shock and the related multiple organ dysfunction still remain the leading cause of mortality in intensive care units (ICUs) worldwide. Defining sepsis is a difficult task, but what is even more challenging is differentiating infection-induced from non-infection-induced systemic inflammatory response-related multiple organ dysfunction. As conventional signs of infection are often unreliable in intensive care, biomarkers are used, of which one of the most frequently investigated is procalcitonin. Early stabilisation of vital functions via adequate supportive therapy and antibiotic treatment has resulted in substantial improvements in outcome over the last decades. However, there are certain patients who may need extra help, hence modulation of the immune system and the host's response may also be an important therapeutic approach in these situations. Polyclonal intravenous immunoglobulins have been used in critical care for decades. A relatively new potential approach could be attenuation of the overwhelming cytokine storm by specific cytokine adsorbents. Both interventions have been applied in daily practice on a large scale, with firm pathophysiological rationale but weak evidence supported by clinical trials. The purpose of this review is to give an overview on the pathophysiology of sepsis as well as the role and interpretation of biomarkers and their potential use in assisting adjunctive therapies in sepsis in the future.

Procalcitonin as a diagnostic marker of ventilator-associated pneumonia in cardiac surgery patients

The aim of the present study was to assess whether procalcitonin (PCT) can be used as a diagnostic marker for ventilator-associated pneumonia (VAP) in cardiac surgery patients. Between January 2012 and June 2013, a total of 92 patients were recruited and divided into non-VAP (59 patients) and VAP (33 patients) groups. The preoperative and postoperative characteristics of the patients were recorded. Serum levels of PCT, interleukin (IL)-6 and C-reactive protein (CRP) were measured using an electrochemiluminescence immunoassay. Subsequently, receiver operating characteristic curves of the PCT, IL-6 and CRP levels were constructed. In addition, associations between the sequential organ failure assessment (SOFA) scores and the serum levels of PCT, IL-6 and CRP in the VAP patients were analyzed. No statistically significant difference was observed between the non-VAP and VAP patients in the occurrence of postoperative complications. However, the SOFA scores (days 1 and 7), the duration of stay in the intensive care unit and the mechanical ventilation time were all significantly higher in the VAP group when compared with the non-VAP group (P<0.05). The optimum PCT cut-off value for VAP diagnosis on day 1 was 5.0 ng/ml, with a sensitivity of 91% and a specificity of 71%. The serum PCT levels on days 1 and 7 were found to correlate positively with the SOFA scores (r=0.54 and r=0.66 for days 1 and 7, respectively). Therefore, the results suggested that serum PCT may be used as diagnostic marker for VAP in patients following cardiac surgery.

Cytokines and chemokines as biomarkers of community-acquired bacterial infection

Routinely used biomarkers of bacterial etiology of infection, such as C-reactive protein and procalcitonin, have limited usefulness for evaluation of infections since their expression is enhanced by a number of different conditions. Therefore, several inflammatory cytokines and chemokines were analyzed with sera from patients hospitalized for moderate bacterial and viral infectious diseases. In total, 57 subjects were enrolled: 21 patients with community-acquired bacterial infections, 26 patients with viral infections, and 10 healthy subjects (control cohorts). The laboratory analyses were performed using Luminex technology, and the following molecules were examined: IL-1Ra, IL-2, IL-4, IL-6, IL-8, TNF-α, INF-γ, MIP-1β, and MCP-1. Bacterial etiology of infection was associated with significantly (P < 0.001) elevated serum concentrations of IL-1Ra, IL-2, IL-6, and TNF-α in comparison to levels observed in the sera of patients with viral infections. In the patients with bacterial infections, IL-1Ra and IL-8 demonstrated positive correlation with C-reactive protein, whereas, IL-1Ra, TNF-α, and MCP-1 correlated with procalcitonin. Furthermore, elevated levels of IL-1Ra, IL-6, and TNF-α decreased within 3 days of antibiotic therapy to levels observed in control subjects. The results show IL-1Ra as a potential useful biomarker of community-acquired bacterial infection.