The accuracy of C-reactive protein in diagnosing acute appendicitis--a meta-analysis

Inflammatory Signals Across the Spectrum: A Detailed Exploration of Acute Appendicitis Stages According to EAES 2015 Guidelines

Background: In this retrospective study, we evaluate the diagnostic utility of C-reactive protein (CRP) and leucocyte count within the EAES 2015 guidelines for acute appendicitis (AA) in differentiating uncomplicated (UAA) from complicated AA (CAA). Methods: Conducted at a tertiary care center in Germany, the study included 285 patients over 18 years who were diagnosed with AA from January 2019 to December 2021. Patient data included demographics, inflammatory markers, and postoperative outcomes. Results: CRP levels (Md: 60.2 mg/dL vs. 10.5 mg/dL; p < 0.001) and leucocyte count (Md: 14.4 Gpt/L vs. 13.1 Gpt/L; p = 0.016) were higher in CAA. CRP had a medium diagnostic value for detecting CAA (AUC = 0.79), with a cutoff at 44.3 mg/L, making it more likely to develop CAA. Leucocyte count showed low predictive value for CAA (AUC = 0.59). CRP ≥ 44.3 mg/L was associated with a higher risk of postoperative complications (OR: 2.9; p = 0.002) and prolonged hospitalization (OR: 3.5; p < 0.001). Conclusions: CRP, within the context of the EAES classification, presents as a valuable diagnostic marker to distinguish CAA from UAA, with a higher risk of postoperative complications and hospitalization. Leucocyte count showed low diagnostic value for the identification of CAA.

Gene Expression Profiling in Pediatric Appendicitis

Importance

Appendicitis is the most common indication for urgent surgery in the pediatric population, presenting across a range of severity and with variable complications. Differentiating simple appendicitis (SA) and perforated appendicitis (PA) on presentation may help direct further diagnostic workup and appropriate therapy selection, including antibiotic choice and timing of surgery.

Objective

To provide a mechanistic understanding of the differences in disease severity of appendicitis with the objective of developing improved diagnostics and treatments, specifically for the pediatric population.

Design, Setting, and Participants

The Gene Expression Profiling of Pediatric Appendicitis (GEPPA) study was a single-center prospective exploratory diagnostic study with transcriptomic profiling of peripheral blood collected from a cohort of children aged 5 to 17 years with abdominal pain and suspected appendicitis between November 2016 and April 2017 at the Alberta Children's Hospital in Calgary, Alberta, Canada, with data analysis reported in August 2023. There was no patient follow-up in this study.

Exposure

SA, PA, or nonappendicitis abdominal pain.

Main Outcomes and Measures

Blood transcriptomics was used to develop a hypothesis of underlying mechanistic differences between SA and PA to build mechanistic hypotheses and blood-based diagnostics.

Results

Seventy-one children (mean [SD] age, 11.8 [3.0] years; 48 [67.6%] male) presenting to the emergency department with abdominal pain and suspected appendicitis were investigated using whole-blood transcriptomics. A central role for immune system pathways was revealed in PA, including a dampening of major innate interferon responses. Gene expression changes in patients with PA were consistent with downregulation of immune response and inflammation pathways and shared similarities with gene expression signatures derived from patients with sepsis, including the most severe sepsis endotypes. Despite the challenges in identifying early biomarkers of severe appendicitis, a 4-gene signature that was predictive of PA compared to SA, with an accuracy of 85.7% (95% CI, 72.8-94.1) was identified.

Conclusions

This study found that PA was complicated by a dysregulated immune response. This finding should inform improved diagnostics of severity, early management strategies, and prevention of further postsurgical complications.

The Diagnostic Accuracy of Hyperbilirubinemia in Predicting Appendicitis and Appendiceal Perforation

Background Every diagnostic tool that may assist in the identification of appendicitis is of great importance to emergency general surgeons. While recent research has indicated that hyperbilirubinemia can serve as a valuable predictor of appendiceal perforation, these studies have not specifically examined the role of bilirubin as an indicator for acute appendicitis. This study aimed to assess the role of hyperbilirubinemia as a diagnostic factor in detecting appendicitis and appendiceal perforation. Methodology This single-center retrospective study involved 333 patients with acute appendicitis who underwent an emergency appendectomy at a model three hospital between January 2021 and December 2022. Statistical analysis was performed using STATA/SE 18.0 for Windows (StataCorp., College Station, TX, USA) to compare bilirubin levels, white blood cell count (WCC), and C-reactive protein (CRP) among normal appendices, non-perforated appendicitis, and perforated appendicitis. Results Among 333 patients, 60.66% were male, and 39.34% were female, with a male-to-female ratio of 1.54:1. The average hospital stay was 3.27 ± 3.02 days. Hyperbilirubinemia was observed in 25.53% (85 individuals). Among the 51 cases of perforated appendicitis, 70.59% had elevated bilirubin levels of above 20 μmol/L. Significantly more patients with appendiceal perforation had hyperbilirubinemia than non-perforated appendicitis (70.59% vs. 19.03%, p < 0.001). Bilirubin had higher specificity (94.29%) for detecting non-perforated appendicitis than normal appendices (odds ratio = 3.88), while WCC and CRP showed higher sensitivities. WCC had a sensitivity of 73.28% and a specificity of 42.86%, and CRP had a sensitivity of 76.53% and a specificity of 60.00%. When comparing perforated appendicitis with non-perforated appendicitis, bilirubin showed a specificity of 80.97% and an odds ratio of 10.21. The likelihood of a patient with hyperbilirubinemia having perforated appendicitis was more than 10 times higher than those without appendiceal perforation, suggesting it to be a potential indicator for appendiceal perforation. WCC showed a specificity of 26.72% and an odds ratio of 4.28, while CRP had a specificity of 23.48% and an odds ratio of 4.91. Conclusions The significant association between bilirubin levels and appendicitis highlights its potential as a valuable marker for predicting appendicitis and appendiceal perforation. The simplicity, cost-effectiveness, and diagnostic value of bilirubin assessment support its routine use in suspected cases of acute appendicitis.

The relation between C-reactive protein and serum amyloid A in patients with autoinflammatory diseases

BACKGROUND

Autoinflammatory diseases are rare disorders of the innate immune system characterized by fever and other signs of inflammation. A feared complication of autoinflammatory diseases is the development of AA amyloidosis. AA amyloidosis is caused by extracellular deposition of soluble serum amyloid A (SAA) proteins as insoluble amyloid fibrils leading to organ damage. Prolonged high levels of SAA are a prerequisite to develop AA amyloidosis. Since measurement of SAA is relatively expensive and sometimes unavailable, C-reactive protein (CRP) is often used as a surrogacy marker to test for inflammation.

OBJECTIVE

The aim of this research is to evaluate the possible relation between CRP and SAA.

METHODS

A retrospective cohort of patients with autoinflammatory diseases (n = 99) where SAA and CRP blood testing was performed in the period between 2015 and 2021 in the University Medical Centre in Groningen was used to investigate the correlation between CRP and SAA.

RESULTS

CRP and SAA have a high correlation (rho = 0.755, p < 0.001). A CRP value below 0.45 mg/L results in 100% sensitivity for SAA below 4 mg/L. CRP below 5 mg/L is a good predictor of SAA below 4 mg/L with 85.4% sensitivity and 83.6% specificity. Only prednisone and erythrocyte sedimentation rate (ESR) significantly influence the relation between CRP and log₁₀SAA.

CONCLUSION

There was a significant correlation between CRP and SAA in our retrospective cohort. CRP levels below 5 mg/L proved to be highly predictive of SAA levels below 4 mg/L. This may not be true for patients on steroids.

A study of C-reactive protein and D-dimer in patients of appendicitis

BACKGROUND

Acute appendicitis is the most common abdominal surgical emergencies across the world.

OBJECTIVE

The aim of this study was to determine the value of C-reactive protein (CRP) and D-dimer as diagnostic markers of acute appendicitis.

STUDY DESIGN

It was a Prospective observational clinical study.

METHOD

The present study was carried out in General Surgical Unit of University Hospital, Institute of Medical Sciences, Banaras Hindu University, Varanasi from September 2015 to July 2017. All data including patient's demography, clinical examination, laboratory test results, and appendix histology were summarized. Receiver operating characteristic (ROC) curve of TLC, CRP, and D-dimer was analyzed.

RESULTS

Total 65 patients who presented with periumbilical pain or pain in right iliac fossa (RIF) were included in the study. The mean age of the patients was 31.18 ± 14.59 years (range: 15 to 65 years) with male : female ratio was 2.21:1. The most common symptom was pain in right iliac fossa (100%) followed by nausea/vomiting (69.2%). The mean leucocyte count, CRP, and D-dimer levels were significantly raised in appendicitis group as compared to negative appendicectomy group (P = 0.025, P = 0.036, and P = 0.025, respectively). The receiver operating characteristic (ROC) curve for TLC was not helpful for differentiating between appendicitis and negative appendicitis (P = 0.073). In addition, D-dimer was helpful for differentiating between appendicitis and negative appendicitis (P = 0.002). However, CRP was also found to be helpful for differentiating between appendicitis and negative appendicitis (P = 0.030).

CONCLUSION

The diagnosis of appendicitis remains multifactorial and biochemical markers like CRP and D-dimer may help to guide the surgeon in the decision making.

Value of early change of serum C reactive protein combined to modified Alvarado score in the diagnosis of acute appendicitis

Background

The aim of this study is to test the diagnostic value of baseline and early change of C-reactive protein (CRP) concentrations, evaluated separately or in combination with the modified Alvarado score (MAS), in patients with clinically suspected acute appendicitis.

Methods

This is a prospective observational study including all patients presenting to the emergency department with an equivocal diagnosis of acute appendicitis. After inclusion, clinical and demographic data are recorded and blood samples were taken at baseline and 3 h after for serum CRP measurements (3 h CRP). The MAS is also calculated for all patients. The ultimate diagnosis of appendicitis was based on the histologic findings of the excised appendix in operated patients and clinical follow-up in emergency department discharged patients. Diagnostic accuracy of admission CRP, early change of CRP 3 h CRP minus admission CRP, MAS and the combination of these parameters was expressed by sensitivity, specificity, positive predictive value, negative predictive value and area under receiver operating characteristics curve.

Results

Five hundred patients were included from January 2010 to December 2013. Overall, 387 patients were operated the negative appendectomy rate was 8,3%. CRP concentrations were higher in patients with acute appendicitis. However, the diagnostic value of admission CRP, delta CRP and MAS was moderate with area under ROC curve respectively equal to 0.63, 0.53 and 0.6. Combining admission CRP and delta CRP values to MAS did not result in a better performance. The area under ROC curve did not exceed 0.7 with the different combinations.

Conclusion

Early change of CRP has a moderate diagnostic value in patients with clinically suspected acute appendicitis. Combining CRP values to MAS did not improve diagnostic accuracy.

Delta neutrophil index as an early predictor of acute appendicitis and acute complicated appendicitis in adults

Background

This retrospective study aimed to evaluate the ability of the delta neutrophil index (DNI) to predict histologically normal appendicitis preoperatively and to differentiate between simple and complicated appendicitis.

Methods

The data from 650 patients were divided into positive and negative appendectomy groups (histologically normal appendicitis). The patients in the acute appendicitis group were further sub-divided into simple and complicated appendicitis groups.

Results

The DNI was significantly higher in the positive group than in the negative appendectomy group (0.4 vs. −0.4, p < 0.001) as well as in the complicated group compared with that in the simple appendicitis group (1.2 vs. 0.3, p < 0.001). The DNI independently predicted a positive appendectomy and an acute complicated appendicitis in multivariate logistic regression analysis [odds ratio (OR) 2.62, 95% confidence interval (CI) (1.11~6.16), p = 0.028 and odds ratio (OR) 4.10, 95% confidence interval (CI) (2.94~5.80), p < 0.001]. The optimum cut-off for a positive appendectomy and acute complicated appendicitis were 0.2 [area under curve (AUC) 0.709] and 0.6 (AUC 0.727).

Conclusions

We suggest that obtaining a preoperative DNI is a useful parameter to aid in the diagnosis of histologically normal appendicitis and to differentiate between simple and complicated appendicitis.

Efficacy of the Evaluation of Inflammatory Markers for the Reduction of Negative Appendectomy Rates

Unnecessary appendectomy can cause complications; ways of reducing negative appendectomy rates (NAR) using biochemical and imaging methods are desirable. We retrospectively examined 640 patients who underwent appendectomy for suspected AA. Patients with histologically confirmed appendicitis were designated the positive appendectomy group (n = 565), whereas those with unconfirmed appendicitis were designated the negative appendectomy group (n = 75). The positive appendectomy group was subdivided into the non-perforated (n = 511) and perforated (n = 54) appendectomy groups according to pathology reports. We compared the age, sex, lymphocyte count, neutrophil percentage, pathologic positivity or negativity for appendicitis, C-reactive protein (CRP) level, neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR) of the patients. When the perforated, non-perforated, and negative appendectomy groups were compared, the highest CRP level, NLR, and PLR were evident in the perforated appendectomy group (p = 0.001), whereas the lowest neutrophil percentage was found in the non-perforated appendectomy group (p = 0.001). Multiple logistic regression analysis identified neutrophil percentage, CRP value, and NLR as independent variables and demonstrated that AA could be diagnosed with 88.9 % accuracy using the cutoff values determined. In patients with suspected AA, particularly in rural areas with limited access to advanced imaging modalities, the evaluation of neutrophil percentage, CRP level, and NLR, in combination with the findings of a physical examination, may aid diagnosis and reduce NAR.

WSES Jerusalem guidelines for diagnosis and treatment of acute appendicitis

Acute appendicitis (AA) is among the most common cause of acute abdominal pain. Diagnosis of AA is challenging; a variable combination of clinical signs and symptoms has been used together with laboratory findings in several scoring systems proposed for suggesting the probability of AA and the possible subsequent management pathway. The role of imaging in the diagnosis of AA is still debated, with variable use of US, CT and MRI in different settings worldwide. Up to date, comprehensive clinical guidelines for diagnosis and management of AA have never been issued. In July 2015, during the 3rd World Congress of the WSES, held in Jerusalem (Israel), a panel of experts including an Organizational Committee and Scientific Committee and Scientific Secretariat, participated to a Consensus Conference where eight panelists presented a number of statements developed for each of the eight main questions about diagnosis and management of AA. The statements were then voted, eventually modified and finally approved by the participants to The Consensus Conference and lately by the board of co-authors. The current paper is reporting the definitive Guidelines Statements on each of the following topics: 1) Diagnostic efficiency of clinical scoring systems, 2) Role of Imaging, 3) Non-operative treatment for uncomplicated appendicitis, 4) Timing of appendectomy and in-hospital delay, 5) Surgical treatment 6) Scoring systems for intra-operative grading of appendicitis and their clinical usefulness 7) Non-surgical treatment for complicated appendicitis: abscess or phlegmon 8) Pre-operative and post-operative antibiotics.

Acute Appendicitis: The Reliability of Diagnosis by Clinical Assessment Alone

Background and Aims:

This prospective study aimed to review the trustworthiness of the initial clinical assessment in acute appendicitis without employment of imaging modalities, laparoscopy or any other adjunct diagnostic test.

Patients and Methods:

717 patients were operated on for appendicitis by six different surgeons. Initial clinical and laboratory examination were evaluated in relation to the intraoperative and the pathological appreciation of the appendiceal inflammation.

Results:

598 patients were found to have appendicitis, 34 a different condition, 41 had both appendicitis and an additional condition and 44 no pathology. 6% of the laparotomies and 11 % of the appendectomies were unnecessary. The severity of the inflammation correlated significantly with periumbilical pain, pain migrating to right lower quadrant, loss of appetite, fever, rebound tenderness, local rigidity, polymorphonuclear predominance on deferential, polymorhonucleosis and leukocytosis. Leukocytosis was less frequent in aged patients. All the six surgeons were found to be equally reliable, although they all underestimated the setting compared to the pathologists. Patients with a long duration of symptoms had milder forms of inflammation and increased percentage of unanticipated abdominal conditions.

Conclusions:

Appendicitis can be reliably diagnosed clinically without employment of adjunct tests. These can be reserved for equivocal cases.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

C-reactive protein and white blood cell count as triage test between urgent and nonurgent conditions in 2961 patients with acute abdominal pain

The purpose of this article is to assess the diagnostic accuracy of C-reactive protein (CRP) and white blood cell (WBC) count to discriminate between urgent and nonurgent conditions in patients with acute abdominal pain at the emergency department, thereby guiding the selection of patients for immediate diagnostic imaging.Data from 3 large published prospective cohort studies of patients with acute abdominal pain were combined in an individual patient data meta-analysis. CRP levels and WBC counts were compared between patients with urgent and nonurgent final diagnoses. Parameters of diagnostic accuracy were calculated for clinically applicable cutoff values of CRP levels and WBC count, and for combinations.A total of 2961 patients were included of which 1352 patients (45.6%) had an urgent final diagnosis. The median WBC count and CRP levels were significantly higher in the urgent group than in the nonurgent group (12.8 ×10/L; interquartile range [IQR] 9.9-16) versus (9.3 ×10/L; IQR 7.2-12.1) and (46  mg/L; IQR 12-100 versus 10  mg/L; IQR 7-26) (P < 0.001).The highest positive predictive value (PPV) (85.5%) and lowest false positives (14.5%) were reached when cutoff values of CRP level >50  mg/L and WBC count >15 ×10/L were combined; however, 85.3% of urgent cases was missed.A high CRP level (>50  mg/L) combined with a high WBC count (>15 ×10/L) leads to the highest PPV. However, this applies only to a small subgroup of patients (8.7%). Overall, CRP levels and WBC count are insufficient markers to be used as a triage test in the selection for diagnostic imaging, even with a longer duration of complaints (>48  hours).

An update on common gastrointestinal emergencies

The evaluation of the child with acute abdominal pain often poses as a diagnostic challenge due to the wide range of diagnoses. Surgical emergencies need to be rapidly identified and managed appropriately to minimize morbidity and mortality. Presenting symptoms, clinical examination, and laboratory findings can guide selection of diagnostic imaging. This article reviews common surgical causes of abdominal pain in children.

The diagnostic value of white cell count, C-reactive protein and bilirubin in acute appendicitis and its complications

INTRODUCTION

Inflammatory markers such as white cell count (WCC) and C-reactive protein (CRP) and, more recently, bilirubin have been used as adjuncts in the diagnosis of appendicitis. The aim of this study was to determine the diagnostic accuracy of the above markers in acute and perforated appendicitis as well as their value in excluding the condition.

METHODS

A retrospective analysis of 1,169 appendicectomies was performed. Patients were grouped according to histological examination of appendicectomy specimens (normal appendix = NA, acute appendicitis = AA, perforated appendicitis = PA) and preoperative laboratory test results were correlated. Receiver operating characteristic (ROC) curve area analysis (area under the curve [AUC]) was performed to examine diagnostic accuracy.

RESULTS

ROC analysis of all laboratory variables showed that no independent variable was diagnostic for AA. Good diagnostic accuracy was seen for AA when all variables were combined (WCC/CRP/bilirubin combined AUC: 0.8173). In PA, the median CRP level was significantly higher than that of AA (158mg/l vs 30mg, p<0.0001). CRP also showed the highest sensitivity (100%) and negative predictive value (100%) for PA. CRP had the highest diagnostic accuracy in PA (AUC: 0.9322) and this was increased when it was combined with WCC (AUC: 0.9388). Bilirubin added no diagnostic value in PA. Normal levels of WCC, CRP and bilirubin could not rule out appendicitis.

CONCLUSIONS

CRP provides the highest diagnostic accuracy for PA. Bilirubin did not provide any discriminatory value for AA and its complications. Normal inflammatory markers cannot exclude appendicitis, which remains a clinical diagnosis.

Clinical value of total white blood cells and neutrophil counts in patients with suspected appendicitis: retrospective study

Introduction

Acute appendicitis (AA) is common surgical problem associated with acute-phase reaction. Blood tests role in decision-making process is unclear. This retrospective study aimed to determine diagnostic value of preoperative evaluation of white blood cells (WBCs) and neutrophils and its value in predicting AA severity.

Methods

Medical records of 456 patients who underwent appendectomy during 4-years period were retrospectively reviewed. Patients were subdivided according to histological finding into: normal appendix (n = 29), uncomplicated inflamed appendix (n = 350), complicated appendicitis (n = 77). Diagnostic performances of WBCs and neutrophils were analyzed using receiver operating characteristic (ROC) curves.

Results

WBCs and neutrophils counts were higher in patients with inflamed and complicated appendix than normal appendix and in complicated than inflamed appendix. In patients, WBCs count 9.400 × 10³/mL had sensitivity of 76.81%, specificity of 65.52%, positive predictive value (PPV) of 97.0%, negative predictive value (NPV) of 16.1%, positive likelihood ratio [LR(+)] of 2.23, negative LR(−) of 0.35. Neutrophil count 7.540 × 10³/mL had sensitivity of 70.96%, specificity of 65.52%, PPV of 96.8%, NPV of 13.3%, LR(+) of 2.06, LR(−) of 0.44. Areas under ROC curve were 0.701, 0.680 for elevated WBCs and neutrophils count.

Conclusions

Clinicians should not rely on either elevated WBCs or neutrophils count as appendicitis indicator as clinical data are superior in decision-making appendectomy.

Local and systemic expressions of MMP-9, TIMP-1 and PAI-1 in patients undergoing surgery for clinically suspected appendicitis

BACKGROUND/AIMS

To examine, compare and correlate the expressions of matrix metalloproteinase 9 (MMP-9), tissue inhibitor of metalloproteinase 1 (TIMP-1) and plasminogen activator inhibitor type 1 (PAI-1) in appendiceal tissue and pre- and postoperative blood samples in patients undergoing surgery for clinically suspected appendicitis.

METHODS

Fifty-seven patients with complete tissue and blood samples were included and divided into groups of noninflamed appendix/lymphadenitis (n = 7), phlegmonous appendicitis (n = 30), gangrenous appendicitis (n = 11) and perforated appendicitis (n = 9). The protein expressions were assessed with ELISAs. The local expressions of MMP-9, TIMP-1 and PAI-1 were correlated with the systemic expressions at the time of surgery while the systemic individual differences between surgery and recovery were compared.

RESULTS

There was a positive correlation between tissue and plasma PAI-1 (p < 0.05). The individual differences for plasma MMP-9 and PAI-1 were statistically nonsignificant, while they were higher for TIMP-1 in patients with perforated appendicitis compared with phlegmonous (p < 0.0001) and gangrenous appendicitis (p < 0.01).

CONCLUSIONS

Plasma PAI-1 reflected the levels in appendiceal tissue at the time of surgery. Systemic TIMP-1 could have the potential of distinguishing perforated from nonperforated appendicitis.

The diagnostic value of D-dimer, procalcitonin and CRP in acute appendicitis

BACKGROUND

The early diagnosis of acute abdomen is of great importance. To date, several inflammatory markers have been used for the diagnosis of acute abdominal conditions, including acute appendicitis. The aim of this study was to evaluate the diagnostic utility of D-dimer, Procalcitonin (PCT) and C-reactive protein (CRP) measurements in the acute appendicitis.

METHODS

This prospective study was conducted between March 1(st), 2010 and July 1(st), 2011. In this period, seventy-eight patients were operated with the diagnosis of acute appendicitis, and D-dimer, PCT and CRP levels of the patients were measured. The patients were grouped as phlegmonous appendicitis (Group 1), gangrenous appendicitis (Group 2), perforated appendicitis (Group 3) and negative appendectomy (Group 4) according to the surgical findings and histopathological results.

RESULTS

Of 78 patients, 54 (69.2 %) were male and 24 (30.8 %) were female, and the mean age was 25.4 ± 11.1 years (range, 18 to 69 years). 66 (84.6 %) patients had increased leukocyte count (white blood cell count). The PCT values were higher than the upper normal limit in 20 (25.6%) patients, followed by D-dimer in 22 (28.2 %) patients and CRP in 54 (69.2 %) patients. The diagnostic value of leukocyte count and CRP in acute appendicitis was higher than that of the other markers, whereas leukocyte count showed very low specificity. CRP values were higher in perforated appendicitis when compared with the phlegmonous appendicitis (p < 0.05). However, PCT and D-dimer showed lower diagnostic values (26% and 31%, respectively).

CONCLUSION

An increase in CRP levels alone is not sufficient to make the diagnosis of acute appendicitis. However, CRP levels may differentiate between phlegmonous appendicitis and perforated appendicitis. Due to their low sensitivity and diagnostic value, PCT and D-dimer are not better markers than CRP for the diagnosis of acute appendicitis.

The value of hyperbilirubinaemia in the diagnosis of acute appendicitis

INTRODUCTION

No reliably specific marker for acute appendicitis has been identified. Although recent studies have shown hyperbilirubinaemia to be a useful predictor of appendiceal perforation, they did not focus on the value of bilirubin as a marker for acute appendicitis. The aim of this study was to determine the value of hyperbilirubinaemia as a marker for acute appendicitis.

MATERIALS AND METHODS

A retrospective analysis of appendicectomies performed in two hospitals (n=472). Data collected included laboratory and histological results. Patients were grouped according to histology findings and comparisons were made between the groups.

RESULTS

The mean bilirubin levels were higher for patients with simple appendicitis compared to those with a non-inflamed appendix (p<0.001). More patients with simple appendicitis had hyperbilirubinaemia on admission (30% vs 12%) and the odds of these patients having appendicitis were over three times higher (odds ratio: 3.25, p<0.001). Hyperbilirubinaemia had a specificity of 88% and a positive predictive value of 91% for acute appendicitis. Patients with appendicitis who had a perforated or gangrenous appendix had higher mean bilirubin levels (p=0.01) and were more likely to have hyperbilirubinaemia (p<0.001). The specificity of hyperbilirubinaemia for perforation or gangrene was 70%. The specificities of white cell count and C-reactive protein were less than hyperbilirubinaemia for simple appendicitis (60% and 72%) and perforated or gangrenous appendicitis (19% and 36%).

CONCLUSIONS

Hyperbilirubinaemia is a valuable marker for acute appendicitis. Patients with hyperbilirubinaemia are also more likely to have appendiceal perforation or gangrene. Bilirubin should be included in the assessment of patients with suspected appendicitis.

Diagnostic accuracy of white cell count and C-reactive protein for assessing the severity of paediatric appendicitis

OBJECTIVES

Simple investigations like white cell count (WCC) and C-reactive protein (CRP) may help to improve the accuracy of diagnosis in paediatric appendicitis. We evaluated the diagnostic accuracy of WCC and CRP for the severity of acute appendicitis in children.

DESIGN

Cross-sectional study.

SETTING

This study was conducted on all children who underwent open appendectomy from January 2007 to December 2008 at a District General Hospital. Data regarding demographics, WCC, CRP, histology and postoperative complications were analysed.

PARTICIPANTS

All children who underwent open appendectomy during the study period.

MAIN OUTCOME MEASURES

Diagnostic accuracy of WCC and CRP for simple acute appendicitis and a perforated appendix.

RESULTS

Out of 204 patients, 112 (54.9%) were girls. At surgery, appendix was grossly inflamed in 175 of which 32 had perforation. Histology revealed simple acute appendicitis in 135 (66.2%) and gangrenous appendicitis in 32 (15.7%). The rest were normal. The duration of symptoms, temperature, length of stay, WCC and CRP were significantly worse in the perforated group (P value <0.05). Postoperative complications included wound infection (n = 18), pelvic collection (n = 5) and intestinal obstruction (n = 6); and were more common among patients with a perforated appendix (P value <0.05). WCC had a higher diagnostic accuracy and higher sensitivity than CRP in diagnosing simple acute appendicitis. The combined sensitivity of WCC and CRP increased to 95% and 100% for the diagnosis of simple acute appendicitis and a perforated appendix, respectively.

CONCLUSION

Accuracy of WCC is higher than CRP for diagnosing simple acute appendicitis. The combined sensitivity of WCC and CRP increases for simple acute appendicitis as well as a perforated appendix.

Serum chitotriosidase activity in acute appendicitis: preliminary results

Chitotriosidase is one of the most quantitative proteins secreted by activated macrophages, so its activity has been proposed as a biochemical marker of macrophage accumulation. The clinical importance of the chitotriosidase is still largely unknown. Our aim was to evaluate diagnostic accuracy of serum chitotriosidase activity in acute appendicitis (AA). A total of 34 patients with preoperative AA diagnosis (18 men and 16 women; mean age, 28.8±10.9 years) were enrolled in this study. The appendix specimens were classified as normal appendix (10 patients) and AA (24 patients). The serum chitotriosidase activity was measured preoperatively. Diagnostic value of the preoperative chitotriosidase activity as assessed through the corresponding receiver operating characteristic curve was well (area under the curve, 0.771; 95% confidence interval, 0.647-0.877; P<.05). Preoperative serum chitotriosidase activity may be a useful marker for diagnosis of AA, and future studies are required to confirm the results presented here.

Normal inflammatory markers in appendicitis: evidence from two independent cohort studies

OBJECTIVES

Acute appendicitis is a common surgical condition which can lead to severe complications. Recent work suggested that patients experiencing right lower abdominal pain, with normal white cell count (WCC) and C-reactive protein (CRP) are unlikely to have acute appendicitis and can be discharged. We present two independent data-sets that suggest that this strategy may not be risk-free.

DESIGN

Retrospective cohort study of consecutive patients from two district general hospitals. Sensitivity and specificity of CRP, WCC and neutrophil count (NC) in predicting appendicitis were calculated. Markers were analysed using Fisher's exact test and Kruskul-Wallace test.

SETTING

Two district general hospitals in the UK.

PARTICIPANTS

Patients undergoing appendicectomy for suspected appendicitis.

MAIN OUTCOME MEASURES

Inflammatory markers and appendix histology.

RESULTS

A total of 297 patients were included. Appendicitis occurred in four patients with normal CRP, WCC and NC in centre A and 13 patients in centre B. The sensitivity of all three markers combined was 94% (centre A) and 92% (centre B). The specificity was 60% (centre A) and 64% (centre B). No single marker could differentiate uncomplicated and complicated appendicitis, but a raised NC or a CRP >35.5 mg/l predicted complicated appendicitis. CRP, WCC and NC combined differentiated between patients with a normal appendix, uncomplicated appendicitis and complicated appendicitis.

CONCLUSIONS

Appendicitis in the presence of normal inflammatory markers is not uncommon. We disagree with the view of Sengupta et al. who suggest that patients with normal WCC and CRP are unlikely to have appendicitis, and recommend that clinicians be wary of normal inflammatory markers in patients with a high clinical suspicion of appendicitis.

Acute appendicitis: relationships between CT-determined severities and serum white blood cell counts and C-reactive protein levels

OBJECTIVES

The aim of this study was to evaluate the relationships between the severity of appendicitis as depicted on CT and blood inflammatory markers of serum white blood cell (WBC) count and C-reactive protein (CRP).

METHODS

CT images in 128 patients (109 surgically proven and 19 with clinically excluded appendicitis) were retrospectively reviewed. Two radiologists by consensus evaluated and scored (using a 0, 1 or 2 point scale) severities based on CT-determined appendiceal diameters, appendiceal wall changes, caecal changes, periappendiceal inflammatory stranding and phlegmon or abscess formation. We investigated whether CT findings were significantly related to elevated WBC counts or CRP levels and performed the correlations of WBC counts and CRP levels with CT severity scores. Patients were also subjectively classified using four grades from normal (Grade I) to perforated appendicitis (Grade IV) on the basis of CT findings to evaluate differences in WBC counts and CRP levels between grades.

RESULTS

Only appendiceal wall changes and the phlegmon or abscess formation were related to elevated WBC counts and CRP levels, respectively (p<0.05). CT severity scores were found to be more strongly correlated with CRP levels (r = 0.669) than with WBC counts (r = 0.222). On the basis of CT grades, the WBC counts in Grade I were significantly lower than in other grades (p<0.001), whereas CRP levels in Grade IV were significantly higher than in other grades (p<0.001).

CONCLUSION

CRP levels were found to correlate with CT-determined acute appendicitis severity and could be a useful predictor for perforated appendicitis, whereas WBC counts might be useful to detect early acute appendicitis.

Receiver operating characteristic analysis of leukocyte counts in operations for suspected appendicitis

STUDY OBJECTIVE

There has been no clear-cut value of the white blood cell (WBC) count in differential diagnosis of acute appendicitis in emergency medicine. Therefore, the aim of this study was to assess the preoperative WBC counts in 3 groups of patients operated on for a clinical suspicion of acute appendicitis with different findings at appendectomy: uninflamed appendix, uncomplicated acute appendicitis, or complicated acute appendicitis.

METHODS

The medical records of 540 patients who underwent appendectomy for suspected acute appendicitis during a 17-month period were retrospectively reviewed. Data for 3 groups of patients were analyzed to calculate the sensitivity and specificity of the WBC count in the diagnosis of acute appendicitis, and we calculated likelihood ratios for 2 cut-points with either high sensitivity or high specificity. Receiver operating characteristic curves were used to evaluate the WBC count in relation to the true diagnosis and severity of acute appendicitis.

RESULTS

We were able to identify patients with appendicitis on a statistically significant level using receiver operating characteristic curves of WBC counts (area under the curve = 0.756, P < .001), but the WBC count had no diagnostic value in differentiating between uncomplicated and complicated groups (area under the curve = 0.55, P = .086). Likelihood ratio ranged from 1.79 (95% confidence interval, 1.17-2.3) for WBC count of more than 10,500 cells/mm(3) to 3.20 (95% confidence interval, 2.72-3.24) for WBC count of more than 14,300 cells/mm(3).

CONCLUSION

White blood cell count is helpful in the diagnosis and exclusion of appendicitis. However, there is no value to differentiate advanced appendicitis.

Usefulness of laboratory data in the management of right iliac fossa pain in adults

PURPOSE

This study examined the usefulness of inflammatory markers in the management of patients with right iliac fossa pain.

PATIENTS AND METHODS

A single site, prospective observational study was conducted from October 2001 to April 2003. Patients with right iliac fossa pain referred to the surgeon were included. Blood samples were obtained for C-reactive protein, leukocyte, and granulocyte analysis. Clinical, surgical, and histopathologic data were collected. Analysis of inflammatory parameters was performed with logistic regression and areas under the receiver operating characteristic curve were compared.

RESULTS

C-reactive protein increased with the severity of appendicitis and predicted accurately perforation (r(2) = 0.613; P < 0.0005), showing the highest accuracy among inflammatory markers (areas under the receiver operating characteristics curve were 0.846, 0.753, and 0.685 for C-reactive protein, leukocyte and granulocytes, respectively; P < 0.001). Accuracy improved when C-reactive protein and leukocytes were combined; positive and negative predictive values were 93.2 percent and 92.3 percent, respectively.

CONCLUSIONS

C-reactive protein is a helpful marker in the management of patients with right iliac fossa pain; the predictive value improves when combined with leukocyte count. A patient with normal C-reactive protein and leukocytes has a very low probability of appendicitis and should not undergo surgery.

CRP in acute appendicitis--is it a necessary investigation?

BACKGROUND

Appendectomy is one of the commonest procedures in surgery. In spite of various investigations used to improve the accuracy of diagnosis, the rate of normal appendices removed is still about 15-30%. Many studies have investigated the role of C-reactive protein (CRP) in acute appendicitis, but with conflicting results.

METHODS

In a prospective, double blind study, blood for the measurement of serum C-reactive protein was collected pre-operatively from 192 children before going to the operating theatre for appendectomy. The histopathology was grouped into positive (acute appendicitis) and negative (normal appendix) and this was correlated with CRP values.

RESULTS

CRP was normal in 14 out of 33 negative explorations (normal appendix on histopathology). The specificity and sensitivity of serum CRP was 42% and 91% respectively. The predictive value of a positive (raised CRP) and negative (normal CRP) test is 88% and 48% respectively.

CONCLUSION

We conclude that neither raised nor normal CRP value is helpful in the diagnosis of acute appendicitis. CRP is not a good tool for helping the surgeon make the diagnosis of appendicitis and it should not be measured in suspected appendicitis.

Prospective study on the role of C-reactive protein (CRP) in patients with an acute abdomen

INTRODUCTION

C-reactive protein (CRP) is used routinely in many hospitals to evaluate patients with an acute abdomen. We assessed CRP levels in non-specific abdominal pain (NSAP) and surgical conditions requiring operative or non-operative intervention. The aim of this study was to identify a level of CRP that can be useful in differentiating these three groups.

PATIENTS AND METHODS

All patients older than 25 years and admitted with acute abdominal pain other than those requiring emergency surgery were included. CRP within 24 h was assessed in all patients. Various cut-off values (< 6, > 6-50, > 50-100, > 100-150 and > 150 mg/l) were used to identify a useful diagnostic level of CRP in the 3 groups.

RESULTS

A total of 211 patients were prospectively evaluated - 129 women and 82 men with a mean age of 62.4 years (range, 27-92 years). CRP was performed in 196 within 24 h of admission. Sixty had NSAP while 136 had a surgical condition, of whom 69 had an operation/intervention while the rest were treated non-operatively. The median and interquartile (IQ) range for the three groups were: NSAP, 16 mg/l and 7.75-85.75 mg/l; surgical non-operative group, 75 mg/l and 30.5-150 mg/l; and surgical-operative, 111 mg/l and 42-212 mg/l, respectively. These results were statistically significant (P = 0.001). NSAP was diagnosed in 61% of patients at levels < 6 mg/l compared to 39% of patients in the surgical groups. At levels > 150 mg/l, NSAP was diagnosed in 15% of patients compared to only 54% and 31% for the operative and non-operative groups, respectively.

CONCLUSIONS

Despite statistically significant differences between the three groups, no useful level of CRP could be identified to differentiate between patients with NSAP and those requiring operative or non-operative management.

Accurate diagnosis of acute abdomen in FMF and acute appendicitis patients: how can we use procalcitonin?

This study was conducted to define the value of procalcitonin (PCT) levels in the differential diagnosis of abdominal familial Mediterranean fever (FMF) attacks from acute appendicitis. From October 2006 to January 2007, 28 FMF (12 males, 16 females) patients with acute abdominal attacks and 34 patients (18 males) with acute abdomen who underwent operation with the clinical diagnosis of acute appendicitis were consecutively enrolled in this study. FMF patients with concurrent infectious diseases were excluded. PCT values were measured by an immunofluorescent method using the B.R.A.H.M.S. PCT kit (B.R.A.H.M.S. Diagnostica, Berlin, Germany). Erythrocyte sedimentation rate (ESR), C-reactive proteins (CRP) and leucocyte levels were also noted. Mean disease duration in FMF patients was 9.6 +/- 8.1 years (range 2-33 years) and all were on colchicine therapy with a mean colchicine dosage of 1.2 +/- 0.4 mg/day. Among the operated patients, 5 were excluded: 3 patients had normal findings and 2 had intestinal perforation (PCT levels were 2.69 and 4.93 ng/ml, respectively) at operative and pathologic evaluation. There were no significant differences between the two groups with respect to gender and age (p was not significant (NS) for all). Acute phase reactants and PCT levels were increased in patients with FMF compared to patients with acute appendicitis (0.529[0.12 +/- 0.96] vs 0.095 [0.01-0.80] p < 0.001, respectively). PCT levels higher than 0.5 ng/ml were found in 11% (3/28) of FMF patients compared to 62% (18/29) of acute appendicitis patients (p < 0.001). Our results suggest that PCT could be a useful test in the differentiation of abdominal FMF attacks from acute appendicitis, though it should not supplant more conventional investigations.

The role of serum inflammatory markers in acute appendicitis and their success in preventing negative laparotomy

Improving the diagnosis of acute appendicitis in order to prevent unnecessary surgery is crucial. This study was intended to identify the role of serum inflammatory markers in patients with preliminary diagnosis of acute appendicitis with a retrospective design. Eighty-five patients with the preliminary diagnosis of acute appendicitis were recruited in this study within the period of November-December 2003. The average age was 31.8 years (ranged from 15 to 85). There were 62 males (72.9%) and 23 females (27.1%). In addition to performing routine tests, preoperative serum samples were obtained from the patients to measure C-reactive protein, interleukin-6, and interleukin-10. All the patients were operated on for a clinical suspicion of acute appendicitis. Depending on the macroscopic evidence during the operation and the histopathological examination of the specimen, the patients were separated into two groups: the ones who did not have acute appendicitis as the cause for acute abdomen (group I; n = 14) and the ones who had acute appendicitis (group II; n = 71). The ones who had acute appendicitis (group II) were further grouped as noncomplicated appendicitis (group IIA; n = 44) and complicated appendicitis (group IIB; n = 27). Being a male with elevated levels of leukocytes (white blood cells, WBC); C-reactive protein (CRP), interleukin-6 (IL-6); and interleukin-10 increased the probability of having acute appendicitis in patients with evidences of acute abdomen. The risk of complication of acute appendicitis significantly increased when patients had increased levels of C-reactive protein, increased erythrocyte sedimentation rate, and increased interleukin-6 levels, had symptoms for more than 24 h, and were female. Interleukin-10 levels within normal range might be helpful in eliminating the possibility of acute appendicitis. Thus, elevated levels of WBC, IL-6 and CRP might be helpful in confirming a potential diagnosis of acute appendicitis. In addition, normal levels of IL-10 might be of additional help to possibly rule out the diagnosis of acute appendicitis.

Conditional relative odds ratio and comparison of accuracy of diagnostic tests based on 2 x 2 tables

In order to evaluate the accuracy of diagnostic tests based on 2×2 tables, a number of indices were used, some of which are occasionally used inappropriately. This paper demonstrates the characteristics and problems with those indices, and introduces several methods to compare the accuracy of two diagnostic tests. The author summarizes existing indices based on 2×2 tables, agreement rate, kappa (κ), and odds ratio, and reviews their characteristics to find better indices by which to compare two diagnostic tests using hypothetical examples. Because only the odds ratio is not affected by prevalence, the relative odds ratio is the most appropriate index for comparing diagnostic accuracy. In order to decrease selection bias, giving the two tests to the same individuals is preferred. However, no standard method has been established to obtain the standard error of relative odds ratios. In this case, using the newly proposed conditional relative odds ratio (CROR), based on McNemar’s odds ratio, the standard error is available. The CROR is a less biased index when the two tests were given to the same individuals, and it is also preferable in light of its ethical and economic advantages. However, a large base population is required for the two tests to be highly accurate and produce few discordant results.

Laboratory tests in patients with acute appendicitis

BACKGROUND

Laboratory measurements such as leucocyte count, neutrophil percentage and C-reactive protein (CRP) concentration are commonly used as diagnostic aids in patients with suspected acute appendicitis. The present study aimed to clarify the role of these laboratory tests in diagnosing acute appendicitis.

METHODS

The medical records of 897 patients who underwent appendicectomy for suspected acute appendicitis during a 30-month period were retrospectively reviewed. The laboratory findings were correlated with the histopathology of the excised appendices. Data were analysed to calculate the sensitivity and specificity of the individual tests, as well as the test combinations.

RESULTS

Histologically verified appendicitis was found in 740 of the 897 patients (82.5%). The rise in leucocyte count and neutrophil percentage correlated with the degree of appendiceal inflammation. The median CRP level was much higher in the patients with ruptured appendicitis compared with that in patients with a normal appendix (96.8 vs 39.6 mg/L, P < 0.001). However, patients with uncomplicated appendicitis had a lower median CRP concentration than those with a normal appendix, although the difference was not statistically significant (24.1 vs 39.6 mg/L, P = 0.079). The sensitivity of leucocyte count, neutrophil percentage and CRP in diagnosing acute appendicitis was 85.8, 87.2 and 76.5%, respectively, whereas the specificity was 31.9, 33.1 and 26.1%, respectively. Of the 740 patients with acute appendicitis, only six had all three tests simultaneously within the reference interval.

CONCLUSIONS

Abnormal laboratory findings cannot reliably deliver a diagnosis of acute appendicitis. However, acute appendicitis is very unlikely when leucocyte count, neutrophil percentage and CRP level are simultaneously normal.

Ultrasonography in the diagnosis of appendicitis: evaluation by meta-analysis

Objective

We wanted to review the usefulness of ultrasonography (US) for the diagnosis of appendicitis and to evaluate the diagnostic accuracy of US according to patients' and researchers' characteristics.

Materials and Methods

The relevant Korean articles published between 1985 and 2003 were included in this study if the patients had clinical symptoms of acute appendicitis. The histopathologic findings were the reference standard and the data were presented for 2×2 tables. Articles were excluded if patients had no sonographic signs of appendicitis according to graded-compression US. Two reviewers independently extracted the data on study characteristics. The Hasselblad method was used to obtain the combined estimates of sensitivity and specificity for the performance of US.

Results

Twenty-two articles (2,643 patients) fulfilled all inclusion criteria. The estimate of đ calculated by combining the sensitivity and specificity was 2.0054 (95% confidence interval [CI]: 1.8553, 2.1554) by a random effects model. The overall sensitivity and specificity (95% CI) were 86.7% (85.4 to 88.0), and 90.0% (88.9 to 91.2), respectively. According to the subgroup meta-analysis by patients' characteristics, the đ estimate (95% CI) of dominantly younger age, male, and highly clinical suggestive group for US was 2.2388 (1.8758 to 2.6019), 2.7131 (2.2493 to 3.1770), and 2.4582 (1.7387 to 3.1777), respectively. Also, according to subgroup meta-analysis by researchers' characteristics, the đ value (95% CI) for US done by diagnostic radiologists and gray-scale was 2.0195 (1.7942 to 2.2447) and 2.2630 (1.8444 to 2.6815).

Conclusion

This evidence suggests that US may be useful for the diagnosis of acute appendicitis, especially when patients are younger age, male, and highly clinical suggestive.

Appendectomy versus Antibiotic Treatment in Acute Appendicitis. A Prospective Multicenter Randomized Controlled Trial

BACKGROUND

Appendectomy has been the treatment for acute appendicitis for over 120 years. Antibiotic treatment has occasionally been used in small uncontrolled studies, instead of operation, but this alternative has never before been tried in a multicenter randomized trial.

PATIENTS AND METHODS

Male patients, 18-50 years of age, admitted to six different hospitals in Sweden between 1996 and 1999 were enrolled in the study. No women were enrolled by decision of the local ethics committee. If appendectomy was planned, patients were asked to participate, and those who agreed were randomized either to surgery or to antibiotic therapy. Patients randomized to surgery were operated on with open surgery or laparoscopically. Those randomized to antibiotic therapy were treated intravenously for 2 days, followed by oral treatment for 10 days. If symptoms did not resolve within 24 hours, an appendectomy was performed. Participants were monitored at the end of 1 week, 6 weeks, and 1 year.

RESULTS

During the study period 252 men participated, 124 in the surgery group and 128 in the antibiotic group. The frequency of appendicitis was 97% in the surgery group and 5% had a perforated appendix. The complication rate was 14% in the surgery group. In the antibiotic group 86% improved without surgery; 18 patients were operated on within 24 hours, and the diagnosis of acute appendicitis was confirmed in all but one patient, and he was suffering from terminal ileitis. There were seven patients (5%) with a perforated appendix in this group. The rate of recurrence of symptoms of appendicitis among the 111 patients treated with antibiotics was 14% during the 1-year follow-up.

CONCLUSIONS

Acute non-perforated appendicitis can be treated successfully with antibiotics. However, there is a risk of recurrence in cases of acute appendicitis, and this risk should be compared with the risk of complications after appendectomy.

Diagnostic use of C-reactive protein in bacteraemic emergency department patients

OBJECTIVE

To assess C-reactive protein (CRP) as a marker of bacteraemia in ED patients.

METHODS

A retrospective review of a convenience sample of adult patients was conducted at an urban, tertiary care, academic ED. Patients were included in the present study if they had CRP and blood cultures taken during their ED assessment. Neutropenic patients were excluded. Sensitivity, specificity, predictive values and likelihood ratios for CRP in the detection of bacteraemia were calculated.

RESULTS

Over a 12 month period 1214 patients were included in the present study. Blood cultures were positive in 77 (6.3%, 95% confidence interval [CI] 5.0-7.6%), and contaminated in 33 (2.7%, 95% CI 1.8-3.6%). An elevated CRP was 94% sensitive (95% CI 86-98%) and 18% specific (95% CI 16-20%) for concurrent bacteraemia. The positive likelihood ratio for bacteraemia with an elevated CRP was 1.15 (95% CI 1.07-1.23), and the negative likelihood ratio was 0.33 (95% CI 0.23-0.49).

CONCLUSION

Although the present study has limitations, it appears to show that CRP has limited diagnostic utility for the detection of bacteraemia in ED patients.

Serum amyloid A protein levels as a possible aid in the diagnosis of acute appendicitis in children

Hematological and biochemical tests, including white blood cell count (WBC), C-reactive protein (CRP) and other acute-phase reactants, have been used in the diagnosis of acute appendicitis. However, there is controversy among physicians about the value of this practice in children. The objective of our study was to evaluate serum amyloid A protein (SAA) levels in children with confirmed acute appendicitis and to compare the sensitivity and specificity of this marker of inflammation with those for WBC and CRP. A prospective cohort study of 60 children admitted with abdominal pain to rule out appendicitis was used in the study. Of these, 42 underwent surgery, while 18 children who had spontaneous amelioration within 24 h of admission were not operated on and served as controls. WBC and serum SAA and CRP levels were obtained preoperatively. Serum concentrations of the analytes were determined with particle-enhanced immunonephelometric methods. Patients with acute appendicitis had WBC, SAA and CRP levels higher than those of the control group (p<0.001). There was no appendicitis patient with a normal SAA value, while 21.4% of the patients had CRP values within the normal range. The performance of each test was measured by receiver-operating characteristic curves. Area under the curve (AUC) values were 0.849 for WBC, 0.868 for CRP and 0.964 for SAA. The sensitivity and specificity of these methods were 76% and 75% for WBC>10.0 x 10(9) /L, 62% and 94% for CRP>10 mg/L and 86% and 83% for SAA >45.0 mg/L, respectively. Circulating SAA levels have better discriminatory value than WBC or CRP in the assessment of acute appendicitis in children. Thus, this test appears to be of higher value than the current standards of care in the diagnosis of this condition.

A systematic review finds that diagnostic reviews fail to incorporate quality despite available tools

BACKGROUND AND OBJECTIVE

To review existing quality assessment tools for diagnostic accuracy studies and to examine to what extent quality was assessed and incorporated in diagnostic systematic reviews.

METHODS

Electronic databases were searched for tools to assess the quality of studies of diagnostic accuracy or guides for conducting, reporting or interpreting such studies. The Database of Abstracts of Reviews of Effects (DARE; 1995-2001) was used to identify systematic reviews of diagnostic studies to examine the practice of quality assessment of primary studies.

RESULTS

Ninety-one quality assessment tools were identified. Only two provided details of tool development, and only a small proportion provided any indication of the aspects of quality they aimed to assess. None of the tools had been systematically evaluated. We identified 114 systematic reviews, of which 58 (51%) had performed an explicit quality assessment and were further examined. The majority of reviews used more than one method of incorporating quality.

CONCLUSION

Most tools to assess the quality of diagnostic accuracy studies do not start from a well-defined definition of quality. None has been systematically evaluated. The majority of existing systematic reviews fail to take differences in quality into account. Reviewers should consider quality as a possible source of heterogeneity.

Role of Leukocyte Count, Neutrophil Percentage, and C-Reactive Protein in the Diagnosis of Acute Appendicitis in the Elderly

Leukocyte count, neutrophil percentage, and C-reactive protein (CRP) have been shown to give valuable information in the diagnosis of acute appendicitis. However, whether these laboratory tests have the same clinical applicability in the elderly as in young patients remains unclear. This retrospective study aimed to clarify the role of these tests in the diagnosis of acute appendicitis in patients aged 60 years or over. Eighty-five consecutive elderly patients underwent appendectomy for suspected acute appendicitis during a 30-month period. Histologically verified appendicitis was found in 77 of the 85 patients (90.6%). There was no significant difference in leukocyte counts or CRP values between patients with acute appendicitis and those with a normal appendix. The sensitivities of leukocyte count, neutrophil percentage, and CRP in the diagnosis of acute appendicitis were 71.4 per cent, 88.3 per cent, and 90 per cent, respectively, while the specificities were 37.5 per cent, 25 per cent, and 37.5 per cent, respectively. Of 77 patients with acute appendicitis, only two had all three tests simultaneously normal. In conclusion, patients with normal results in all three tests are highly unlikely to have acute appendicitis and should be evaluated with extra caution before surgery.

Urinary 5-hydroxy indole acetic acid as a test for early diagnosis of acute appendicitis

OBJECTIVES

Acute appendicitis (AA) is the most common abdominal emergency. The appendix has abundant serotonin containing cells. Upon inflammation, serotonin is released in the blood and converted into 5-HIAA (5-hydroxy indole acetic acid). Measurement of the urine 5-HIAA (U-5-HIAA) could be a reliable marker of inflammation of the appendix. We have compared the powers of test performance of spot U-5-HIAA and spot U-5-HIAA/creatinin with other routine laboratory tests used for the diagnosis of acute appendicitis.

DESIGN AND METHODS

Urine, serum, and blood samples of 110 patients who were admitted and observed in the emergency units of two university hospitals were studied. 5-HIAA was measured using HPLC, C-reactive protein by immunoturbidometry, WBC by electronic cell counting, and urine creatinine by the Jaffe method. Diagnostic accuracy of the various tests was evaluated by receiver operating characteristic (ROC) analysis.

FINDINGS

The mean of spot U-5-HIAA in 39 patients with AA (nongangrenous) was 32 +/- 2.6 micromol/L, which was much higher than the mean of 40 non-appendicitis patients (NA) (5.5 +/- 0.6), 10 follicular hyperplasia (7.5 +/- 2.1), and 50 healthy control cases (4.1 +/- 0.5) with P < 0.001. The concentration of U-5-HIAA in 21 patients with gangrenous appendicitis (GA) (13.8 +/- 2.1) was also higher than NA patients and healthy individuals but lower than AA cases (P < 0.05). Considering 10 micromol/L as the cutoff point, this test shows 84% sensitivity and 88% specificity, with 90% and 81% positive and negative predictive values, respectively. The area under ROC curve (AUC) of U-5-HIAA in the diagnosis of AA (AUC = 0.903) was much larger than AUCs of U-5-HIAA/Cr (0.787), WBC (0.703), and CRP (0.660).

CONCLUSION

: Urinary secretion of 5-HIAA increases significantly in acute appendicitis and measurement of spot U-5-HIAA gives higher diagnostic accuracy than other routine laboratory tests. While the inflammation progresses to necrosis of the appendix, the concentration of 5-HIAA decreases. This decrease could be a warning sign of perforation of the appendix.

The conditional relative odds ratio provided less biased results for comparing diagnostic test accuracy in meta-analyses

OBJECTIVE

Meta-analytic techniques are used to combine the results of different studies that have evaluated the accuracy of a given diagnostic test. The techniques commonly generate values that either describe the performance of a particular test or compare the discriminative ability of two tests. The later has received very little attention in the literature, and is the focus of this article.

STUDY DESIGN AND SETTING

We summarize existing methods based on an odds ratio (OR) and propose a novel technique for conducting such analysis, the conditional relative odds ratio (CROR). We demonstrate how to extract the required data and calculate several different comparative indexes using a hypothetic example.

RESULTS

A paired analysis is preferred to decrease selection bias and increase statistical power. There is no standard method of obtaining the standard error (SE) of each relative OR; thus, the SE of the summary index might be underestimated under the assumption of no within-study variability.

CONCLUSION

The CROR method estimates less biased indexes with SEs, and conditioned on discordant results, it is much less problematic ethically and economically. However, small cell counts may lead to larger SEs, and it might be impossible to construct McNemar's 2 x 2 tables for some studies.

Application of receiver operating characteristics curve (ROC) analysis when definitive and suspect morphologic flags appear in the new Coulter LH 750 analyzer

Workflow efficiency is important in every laboratory. Manual assessment of white blood cell counts and differentials that have been rejected by an automated analyzer is one of the most time-consuming tasks in the routine hematology laboratory. In this study, receiver operating characteristics (ROC) curve analysis was used for the first time when anomalous distribution and suspect flag alarms appeared in hemograms carried out with the new Beckman Coulter LH 750 analyzer. This article is our second about the LH 750 analyzer published in this journal; we increased the number of cases and describe the novel application of statistical analysis of ROC curves. In processing of specimens from patients with 3% to 6% immature granulocytes (myelocytes + metamyelocytes + bands ), the suspect flag Imm Ne 1 (immature granulocytes) showed 77% diagnostic efficiency with a maximum area under curve (AUC) of 0.71 and a 95% confidence interval (CI) of 0.597 to 0.831 without significant differences between the 3 available levels of alarms in the analyzer (L1, L2, L2). In processing of specimens from patients with >6% immature granulocytes, the Imm Ne 1 flag showed superior diagnostic efficiency of 98% with a maximum AUC of 0.80 and a CI of 0.713 to 0.879. The suspect flag Imm Ne 2 in processing of specimens from patients with >6% of immature granulocytes showed diagnostic efficiency of 92% with a maximum AUC of 0.77 and a CI of 0.665 to 0.871, finding a significant positive difference in level L3 regarding sensitivity in comparison with the other 2 levels of the analyzer (L1, L2). For specimens from patients with >2% blasts, the suspect Blasts alarm showed a diagnostic efficiency of 94%, an AUC of 0.91, and a CI of 0.775 to 1.043; positive differences were observed between the levels L2/L3 and L1. In processing of specimens with variant lymphocytes (large, granular, prolymphocytes, cleaved, chronic lymphocytic leukemia type, and so forth) >10% (x = 14%), the suspect alarm Var Lym (variant lymphocytes) showed a low diagnostic sensitivity of 20% with a maximum AUC of 0.59 and a CI of 0.300 to 0.870 without significant differences between the 3 available levels (L1, L2, L3). However, in processing of specimens presenting values >10% reactive or activated lymphocytes (x = 23%), typical for patients with infectious mononucleosis, the Var Lym flag showed a superior sensitivity of 75% with a diagnostic efficiency of 92% and an AUC of 0.84 with a CI of 0.587 to 1.089. Finally, the laboratory can easily program definitive abnormal morphological flags of distribution (granulocytosis, eosinophilia, monocytosis, and so forth) on the basis of its patient population. In this study we were able to carry out comparisons of AUC and to choose the values for the automated counts in percentage, absolute value, or both. Therefore we were able to define the reliability and impact on the alarm routine to optimize the performance of the user-adjustable definitive alarms for anomalous distribution.

Meta-analysis of the clinical and laboratory diagnosis of appendicitis

BACKGROUND

The importance of specific elements in the clinical diagnosis of appendicitis is controversial. This review analyses the diagnostic value of elements of disease history, clinical findings and laboratory test results in suspected appendicitis.

METHODS

A systematic Medline search was made of all published studies on the clinical and laboratory diagnosis of appendicitis in patients admitted to hospital with suspected disease. Meta-analyses of receiver-operator characteristic (ROC) areas, and positive and negative likelihood ratios, of 28 diagnostic variables described in 24 studies are presented.

RESULTS

Inflammatory response variables (granulocyte count, proportion of polymorphonuclear blood cells, white blood cell count and C-reactive protein concentration), descriptors of peritoneal irritation (rebound and percussion tenderness, guarding and rigidity) and migration of pain were the strongest discriminators, with ROC areas of 0.78 to 0.68. The discriminatory power of the inflammatory variables was particularly strong for perforated appendicitis, with ROC areas of 0.85 to 0.87. Appendicitis was likely when two or more inflammatory variables were increased and unlikely when all were normal.

CONCLUSION

Although all clinical and laboratory variables are weak discriminators individually, they achieve a high discriminatory power when combined. Laboratory examination of the inflammatory response, clinical descriptors of peritoneal irritation, and a history of migration of pain yield the most important diagnostic information and should be included in any diagnostic assessment.

[Leukocyte count, C reactive protein, alpha-1 acid glycoprotein and erythrocyte sedimentation rate in acute appendicitis]

BACKGROUND

The diagnosis of acute appendicitis is clinic, but in some cases, it can present unusual symptoms. The diagnostic difficulties still lead surgeons to unnecessary laparotomies, which reach rates from 15% to 40%. Laboratory exams, then, may become important to complement appendicitis diagnosis. The leucocyte count seems to be the most important value, but measurement of acute phase proteins, specially, the C-reactive protein, is object of several studies.

PATIENTS AND METHODS

This was a prospective study, involving 63 patients submitted to appendecectomies for acute appendicitis suspicion, in "Hospital das Clínicas", Federal University of Uberlândia, MG, Brazil, in whose blood were made dosages of acute phase proteins and the leucocyte count.

RESULTS

The sample was composed by 44 male and 19 female patients, and the majority of them was between 11 and 30 years of age. The flegmonous type was the most freq ent (52.4%). The leucocyte count was altered in 74.6% of the cases and C-reactive protein elevation was observed in 88.9%. The alfa-1 acid glycoprotein and the erithrocyte sedimmentation rate were predominantly normal. The C-reactive protein was augmented in more than 80% of the cases in all ages. Leucocyte count and C-reactive protein were altered in 80% of the patients with the limit of 24 hours from the beginning of symptoms. With clinical evolution time superior than 24 hours, the leucocyte count was altered in 69.7% of the cases, whereas C-reactive protein was in 97%. Sensibility and specificity of the leucocyte count were 88.7% and 20%. For the C-reactive protein, the values were, respectively, 88.9% and 10%. C-reactive protein dosage presented more sensible in cases with more than 24 hours of evolution (96.9%), although with no specificity. The alfa-1 acid glycoprotein and erithrocyte sedimmentation rate presented low sensitivity and specificity.

CONCLUSION

The leucocyte count and the C-reactive protein present significantly altered in acute appendicitis cases, independent from genre or age interval. The leucocyte count and, mainly, the C-reactive protein must be considered in individuals with more than 24 hours of clinical evolution. Augmented values, as a matter of fact, should never substitute the doctor's clinical examination, but complement it. The erithrocyte sedimmentation rate and the alfa-1 acid glycoprotein do not contribute to acute appendicitis diagnosis.