Prospective evaluation of serum procalcitonin in critically ill patients with suspected sepsis- experience from a tertiary care hospital in Pakistan

A Simple Bacteremia Score for Predicting Bacteremia in Patients with Suspected Infection in the Emergency Department: A Cohort Study

Bacteremia is a life-threatening condition that has increased in prevalence over the past two decades. Prompt recognition of bacteremia is important; however, identification of bacteremia requires 1 to 2 days. This retrospective cohort study, conducted from 10 November 2014 to November 2019, among patients with suspected infection who visited the emergency department (ED), aimed to develop and validate a simple tool for predicting bacteremia. The study population was randomly divided into derivation and development cohorts. Predictors of bacteremia based on the literature and logistic regression were assessed. A weighted value was assigned to predictors to develop a prediction model for bacteremia using the derivation cohort; discrimination was then assessed using the area under the receiver operating characteristic curve (AUC). Among the 22,519 patients enrolled, 18,015 were assigned to the derivation group and 4504 to the validation group. Sixteen candidate variables were selected, and all sixteen were used as significant predictors of bacteremia (model 1). Among the sixteen variables, the top five with higher odds ratio, including procalcitonin, neutrophil-lymphocyte ratio (NLR), lactate level, platelet count, and body temperature, were used for the simple bacteremia score (model 2). The proportion of bacteremia increased according to the simple bacteremia score in both cohorts. The AUC for model 1 was 0.805 (95% confidence interval [CI] 0.785-0.824) and model 2 was 0.791 (95% CI 0.772-0.810). The simple bacteremia prediction score using only five variables demonstrated a comparable performance with the model including sixteen variables using all laboratory results and vital signs. This simple score is useful for predicting bacteremia-assisted clinical decisions.

Possible ameliorative role of Spirulina platensis on coagulation factors, lymphocytopenia, and malnutrition in ICU patients with COVID-19

Considering the anti-viral effects of Spirulina platensis (Sp), this study investigated the impact of Sp on impaired blood biomarkers of patients hospitalized in the intensive care unit (ICU) with COVID-19. Therefore, 104 patients (aged 48-66; 61.5% male) were randomly assigned to the Sp (daily consumption of 5 g) or placebo group for 2 weeks. Linear regression analysis was employed to assess the differences in blood test results between the control and intervention groups among patients with COVID-19. Our results showed significant differences in certain hematological tests, including a higher level of hematocrit (HCT) and a lower platelet count (PLT) in the intervention group (p < 0.05). The percentage of lymphocytes (Lym%) in serology testing was significantly different between the control and intervention groups (p = 0.03). In terms of biochemical test analyses, Sp supplementation was associated with reduced levels of both blood urea nitrogen (BUN) and lactate dehydrogenase (LDH) (p = 0.01). Furthermore, on day 14, the intervention group displayed significantly higher medians of serum protein, albumin, and zinc compared to the control group (p < 0.05). Additionally, patients supplemented with Sp had a lower BUN-albumin ratio (BAR) (p = 0.01). No immunological and hormonal differences were observed between groups following 2 weeks. Our analysis indicates that Sp supplementation may be effective in regulating some blood test abnormalities associated with COVID-19. This study was registered at ISRCTN as IRCT20200720048139N1.

Procalcitonin levels in children affected by severe malaria compared to those with uncomplicated malaria in the absence of bacterial infection: a cross-sectional study

BACKGROUND

Procalcitonin is an inflammatory marker strongly associated with the presence of bacterial infection. It has been considered raised in severe malaria infection as opposed to uncomplicated malaria. There are suggestions that it may be raised only when there is concomitant unnoticeable bacterial infection during a malaria crisis. We aimed to assess the difference in plasma procalcitonin levels between children affected by severe and uncomplicated malaria.

METHODS

We assessed plasma procalcitonin levels in 83 children diagnosed with malaria with no clinical and biological evidence of concomitant bacterial infection. Severity of malaria was established using WHO guidelines. Procalcitonin was determined using the ELISA method. Non-parametric Mann-Whitney U test was used to compare medians across the 2 groups. Statistical significance was set for all p values < 0.05.

RESULTS

Of the 83 participants, 28 had uncomplicated malaria, and 55 had severe malaria. PCT levels were obtained in 24 and 40 subjects of each group, respectively, and were similar in both groups; [2.76 (2.52-2.93) vs 2.74 (2.52-2.98) ng/ml, p = 0.916]. The parasite density was lower in the uncomplicated malaria group than in the severe malaria group, but not statistically significant; [22,192 (9110-44 654) vs 31 684 (13 960-73 500) parasites/μl, p = 0.178]. There was no correlation between the parasite density in the general study population and PCT levels (r = 0.072, p = 0.572).

CONCLUSION

In the absence of overt bacterial infection, procalcitonin levels are not different between children affected with uncomplicated malaria and those with severe malaria. Therefore, bacterial infection should be thoroughly checked for in children with raised serum procalcitonin diagnosed with severe malaria.

Procalcitonin as a biomarker of bacterial infection in critically ill patients admitted with suspected Sepsis in Intensive Care Unit of a tertiary care hospital

OBJECTIVE

To compare the diagnostic accuracy of procalcitonin (PCT), C- reactive protein (CRP), total leukocyte count (TLC) and lactate in critically ill patients admitted with suspicion of sepsis.

METHODS

It was a cross sectional study conducted at the department of Chemical Pathology and Endocrinology AFIP, Rawalpindi, in collaboration with Medical and surgical intensive care units (ICU) of CMH Rawalpindi from January 2019 to December 2019. A total of 126 patients of both genders with age above 18 years and fulfilling the inclusion criteria of systemic inflammatory response syndrome (SIRS) were inducted in the study.

RESULTS

Out of 126 patients 82 (65%) patients have positive blood culture results. Male predominance was noted in patients with positive blood culture. Out of 82 patients with positive blood culture results 69(84%) patients have positive PCT results as well whereas 13(15%) patients with positive blood culture results have negative PCT values. 57(69%) patients had Gram negative bacterial infection and 25(30%) patients had Gram positive bacterial infection. Significant difference was noted between the medians of PCT in blood culture positive and blood culture negative group (p value< 0.05) whereas no significant difference was found between medians of CRP, TLC and lactate between blood culture positive and blood culture negative patients (p value > 0.05). ROC curve analysis of PCT, CRP and TLC were done, keeping blood culture as reference standard, PCT showed largest area under the curve (AUC) and clearly outperformed TLC and CRP. PCT showed AUC of 0.781 as compared to CRP and TLC, which was 0.568 and 0.617 respectively. PCT showed sensitivity of 93.9%, specificity of 47.7%, positive predictive value (PPV) of 77% and negative predictive value (NPV) of 80.8%.

CONCLUSION

Higher NPV makes it a reliable marker for screening out sepsis in suspected cases.

Role of Procalcitonin in the Prognosis of Mortality in Patients Admitted to the Intensive Care Unit: A Review Study

Background

This review study aimed to investigate the role of PCT in the prognosis of mortality among patients admitted to the intensive care units (ICU). Procalcitonin (PCT) is a polypeptide and prohormone of calcitonin. This prohormone is secreted by thyroid gland C cells in response to hypercalcemia, and Its elevated level indicates infection, especially bacterial infections, in which there is a systematic response to infection.

Materials and Methods

This narrative review study was performed based on Cochrane collaboration recommendations for reviews. We reviewed all the titles and abstracts of published research articles with the following inclusion criteria studies aimed to confirm the function of a prognostic model in predicting mortality or survival, (b) mortality or survival of a specific endpoint (for example, 30 days), (c) patients admitted to intensive care units, and d) the articles written in English. The exclusion criteria of the current review included: (a) articles whose data were not specifically focused on prognosis of patients in ICU, (b) articles that did not provide sufficient information on the cause of death of patients in ICU, and (c) articles focusing on the treatment of comorbid patients with infections in ICU. The search was conducted on Google Scholar, PubMed, Magiran, ScienceDirect, and SID. Also, to search Iranian databases, including SID and Magiran, the same terms and expressions were searched.

Results

Based on the findings of this review, serum levels of PCT were reported within the range of at least 5 to more than 16 ng/ml in patients admitted to ICU. The mortality rate was estimated at 5.7% to 79% in these patients. Moreover, the incidence of sepsis was reported from 13% to 77.6%.

Conclusion

Serum levels of PCT as a prognostic factor may help early detection, and better classification of the poor prognoses sepsis patients and more invasive treatment of patients admitted to ICU and are at risk for mortality.

Accuracy of Procalcitonin Levels for Diagnosis of Culture-Positive Sepsis in Critically Ill Trauma Patients: A Retrospective Analysis

Background

Abdominal trauma and intra-abdominal sepsis are associated with significant morbidity and mortality. Microcirculation in the gut is disrupted in hemorrhagic and septic shock leading to tissue hypoxia, and the damaged gut acts as a reservoir rich in inflammatory mediators and provides a continual source of inflammation to the systemic circulation leading to sepsis. Sepsis is defined as the presence (probable or documented) of infection together with a systemic inflammatory response to infection. Blood culture is commonly considered to be the preferred approach for diagnosing sepsis, although it is time-consuming, that is, reports are normally available only after 12-48 hours. Procalcitonin levels (PCT) have recently emerged as a promising biomarker in the diagnosis of sepsis. The aim of the present study is to determine the diagnostic accuracy of PCT levels in predicting sepsis in critically ill trauma patients.

Methodology

This was designed as a validation study conducted in the Indoor Department of General Surgery, Liaquat National Hospital, Karachi. The sample size was calculated by taking the estimated frequency of sepsis in suspected patients at 62.13%, expected sensitivity of PCT at 70.83%, and specificity at 84.21% and the desired precision level of 12% for sensitivity; the calculated sample size was 96. The non-probability consecutive sampling method was used to recruit participants who were diagnosed with sepsis on clinical assessment. Blood culture samples were sent for the enrolled patients and a final diagnosis was made on the blood culture report. PCT levels were measured in these suspected patients on the same day of sending blood culture. Diagnostic accuracy of PCT size was measured using the receiver operating characteristic (ROC) curve. ROC curve was formulated for PCT levels against culture-proven sepsis to determine the ideal cut-off value of PCT levels. Two different cut-offs were determined to obtain the highest sensitivity and highest specificity accordingly.

Results

A total of 97 individuals met the inclusion criteria with a mean age of 34.89 ± 10.52 years. Mean PCT levels were 0.96 ± 0.59, with a gender predilection towards females (p < 0.001). No age difference was documented among gender (p = 0.655). The mean duration of intensive care unit stay was 11.73 ± 3.56 days. Culture-proven sepsis was identified in 67.0% of the study participants with a higher PCT level (p < 0.001). Among the 52.6% males included in the study, half were reported to have culture-positive sepsis, but among the 47.4% females culture was positive in 87% (p < 0.001). ROC revealed PCT was predictive for culture-positive sepsis at a cut-off value 0.47 ng/mL (p < 0.001), with a sensitivity of 92.3%, specificity of 68.7%, positive predictive value (PPV) of 85.7%, and negative predictive value (NPV) of 81.5%. By increasing the cut-off value to 0.90 ng/mL at area under the curve of 0.816, the specificity increased to 81.3% and sensitivity became 66.2%, with a PPV of 87.8% and NPV of 54.2%.

Conclusion

Our study determined two cut-values for PCT to predict sepsis, one with the highest sensitivity and the other with better specificity. Other than that, higher PCT levels were significant in female trauma patients. We conclude that PCT is a reliable marker for culture-proven diagnosis of sepsis and may aid physicians/surgeons to promptly manage patients accordingly.

Prognostic Value of Serum Procalcitonin in COVID-19 Patients: A Systematic Review

BACKGROUND

This study is aimed at reviewing the published literature on the prognostic role of serum procalcitonin (PCT) in COVID-19 cases.

DATA RETRIEVAL

We systematically reviewed the literature available on PubMed, MEDLINE, LitCovid NLM, and WHO: to assess the utility of PCT in prognosis of coronavirus disease. Scrutiny for eligible studies comprising articles that have evaluated the prognostic utility of PCT and data compilation was undertaken by two separate investigators. Original articles in human subjects reporting the prognostic role of PCT in adult COVID-19 patients were included. The Quality in Prognosis Studies (QUIPS) tool was utilized to assess the strength of evidence. Results were reported as narrative syntheses.

RESULTS

Out of the total 426 citations, 52 articles passed through screening. The quality of evidence and methodology of included studies was overall acceptable. The total sample size of the studies comprised of 15,296 COVID-19-positive subjects. Majority of the studies were from China, i.e., 40 (77%). The PCT cut-off utilized was 0.05 ng/mL by 18 (35%) studies, followed by 0.5 ng/mL by 9 (17.5%). Eighty five percent (n = 44) studies reported statistically significant association (p value < 0.05) between PCT and severity.

CONCLUSION

Procalcitonin appears as a promising prognostic biomarker of COVID-19 progression in conjunction with the clinical context.

HOW TO CITE THIS ARTICLE

Ahmed S, Jafri L, Hoodbhoy Z, Siddiqui I. Prognostic Value of Serum Procalcitonin in COVID-19 Patients: A Systematic Review. Indian J Crit Care Med 2021;25(1):77-84.

Trend analysis of lab tests requisitions of COVID-19 prognostic biomarkers at a clinical chemistry reference laboratory-an observational study

Background

Biochemical parameters, such as C-reactive protein (C-RP), Procalcitonin (PCT), Lactate dehydrogenase (LDH) and Ferritin are associated with COVID-19 severity and prognosis. This trend analysis of COVID-19 prognostic biomarker requisitions is aimed at providing a reflection of the clinical practices adopted amidst the peak of the pandemic. This knowledge of the prognostic biomarkers utilized, will further aid to classify patients based on their risk, for optimal resource allocation and improve outcomes.

Material & methods

This cross-sectional study was conducted at the clinical chemistry laboratory at the Aga Khan University Hospital (AKUH), Karachi Pakistan. A team consisting of two clinical chemistry consultants reviewed the COVID-19 prognostic biomarkers tests performance data from March to July 2020 using the integrated laboratory information management system (ILMS). The test statistics of March to July 2020 when COVID-19 cases were on the rise in the country were compared with those of the same months from 2019. The changes in the test groups were expressed in percentages. Microsoft Excel for windows 2019 was used for data analysis.

Results

The total specimens received for testing in 2020 (n = 574,092) showed a percent decline of approximately (−) 33% compared to 2019 (n = 858,756). Contrary to the overall decline in volumes an upward surge was noted for the prognostic biomarkers. From March to July, the highest percent change was noted for LDH (+155.1%), followed by PCT (+66.7.1%), C-RP (+26.5%) and Ferritin (+22.1%) in 2020 compared to the same time frame in 2019. The highest percent change was noted in June.

Conclusion

During the COVID 19 pandemic, a significant increase in utilization of laboratory services was seen for COVID-19 prognostic markers.

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During COVID-19, an upward surge was noted for the prognostic biomarkers lab requisitions.

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The highest percent change was noted for LDH (+155.1%), followed by PCT (+66.7.1%), C-RP (+26.5%) and Ferritin (+22.1%).

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The highest percent change was noted in June 2020, followed by a decline in July as the pandemic curve flattened.

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The clinicians applied previous experiences and utilized the prognostic biomarkers to good effect.