Usefulness of urine strip test in the rapid diagnosis of spontaneous bacterial peritonitis

Laboratory testing of extravascular body fluids: National recommendations on behalf of the Croatian Society of Medical Biochemistry and Laboratory Medicine. Part I - Serous fluids

Extravascular body fluids (EBF) analysis can provide useful information in the differential diagnosis of conditions that caused their accumulation. Their unique nature and particular requirements accompanying EBF analysis need to be recognized in order to minimize possible negative implications on patient safety. This recommendation was prepared by the members of the Working group for extravascular body fluid samples (WG EBFS). It is designed to address the total testing process and clinical significance of tests used in EBF analysis. The recommendation begins with a chapter addressing validation of methods used in EBF analysis, and continues with specific recommendations for serous fluids analysis. It is organized in sections referring to the preanalytical, analytical and postanalytical phase with specific recommendations presented in boxes. Its main goal is to assist in the attainment of national harmonization of serous fluid analysis and ultimately improve patient safety and healthcare outcomes. This recommendation is intended to all laboratory professionals performing EBF analysis and healthcare professionals involved in EBF collection and processing. Cytological and microbiological evaluations of EBF are beyond the scope of this document.

Diagnostic Value of Leukocyte Esterase Test Strip Reagents for Rapid Clinical Diagnosis of Spontaneous Bacterial Peritonitis in Patients Admitted to Hospital Emergency Departments in Iran

Background:

Spontaneous bacterial peritonitis (SBP) is a common and important clinical problem and is life-threatening in decompensated liver disease. Ascites fluid test by leukocyte esterase test strip has been recently proposed as an effective and rapid method to diagnose SBP in patients with cirrhosis.

Objectives:

This study aimed to evaluate sensitivity and specificity of leukocyte esterase test strip in the diagnosis of SBP.

Patients and Methods:

The population of this research was all patients with cirrhosis and ascites admitted to the emergency room at Imam Reza (AS) hospital, Mashhad. A written consent was taken for inclusion in the study. 50 mL ascites sample was taken from all patients for use in a urine test strip (LER) (Urine Test Strips Convergys®Urine Matrix 11). The patient’s ascites samples were evaluated for cell counting. Positive dipstick test for LER in this study considered as grade 3 +. The values of WBC > 500 cell/mm³ or PMN > 250 cell/mm³ considered as positive result of the gold standard method for the diagnosis of SBP.

Results:

In this study, 100 patients with ascites due to cirrhosis, with an average age of 38.9 ± 6.54 years were evaluated. Twenty cases had positive results, of whom 17 cases were also detected based on the standard diagnostic criteria and other three cases were healthy individuals. Thus, sensitivity, specificity, positive and negative predictive values, and accuracy of the method were 95%, 96.3%, 85%, 97.5% and 95%, respectively.

Conclusions:

The use of leukocyte esterase urine dipstick test can be a quick and easy method in early diagnosis of SBP to start the treatment until preparation of SBP-cell count results.

EVALUATION OF LEUKOCYTE ESTERASE REAGENT STRIPS TEST IN THE DIAGNOSIS OF SPONTANEOUS BACTERIAL PERITONITIS IN CHILDREN WITH CIRRHOSIS

BACKGROUND

Spontaneous bacterial peritonitis is defined as an ascetic fluid infection without an evident intra-abdominal surgically treatable source. Spontaneous bacterial peritonitis is one of the severe complications in patients with cirrhosis and ascites. Without early antibiotic treatment, this complication is associated with high mortality rate; therefore, early diagnosis and treatment of spontaneous bacterial peritonitis is necessary for survival. Leukocyte esterase reagent can rapidly diagnose the spontaneous bacterial peritonitis.

OBJECTIVE

This study aimed to find out the diagnostic accuracy of leukocyte esterase dipstick test for the diagnosis of spontaneous bacterial peritonitis.

METHODS

A single centered hospital-based cross-sectional study was conducted during July 2013 to August 2014 on children with cirrhotic liver disease and ascites who were admitted in the Department of Pediatric Gastroenterology in Nemazee Hospital affiliated to Shiraz University of Medical Sciences (Iran). All patients underwent abdominal paracentesis, and the ascitic fluid was processed for cell count, leukocyte esterase reagent strip test (Combiscreen SL10) and culture. Spontaneous bacterial peritonitis was defined as having a polymorphonuclear count (PMN ≥250/m3) in ascitic fluid. Sensitivity, specificity, positive predictive value and negative predictive value of leukocyte esterase test were calculated according to the formula.

RESULTS

Totally, 150 ascitic fluid sample of cirrhotic male patients (53.2%) and their mean age (4.33±1.88 years) were analyzed. Biliary atresia (n=44, 29.4%) and idiopathic neonatal hepatitis (n=29, 19.3%) were the most frequent etiology of cirrhosis. Also, abdominal pain (68.6%) and distension (64%) were the most common presenting complaint. Of all cases, 41 patients (27.35%) were diagnosed to have spontaneous bacterial peritonitis (PMN ≥250/mm3). Sensitivity and specificity of leukocyte esterase reagent test according to PMNs ≥250 mm3 were 87.80% and 91.74%, also on ascitic fluid culture results were 88.23% and 77.44%. Positive predictive value and negative predictive value of this test in PMNs ≥250 mm3 were 80% and 95.23% and in cases with positive culture 33.33% and 98.09% were obtained, respectively. Efficiency of leukocyte esterase reagent test in diagnosing spontaneous bacterial peritonitis, according to PMNs ≥250 mm3 and culture results were 90.66% and 78.66%.

CONCLUSION

The leukocyte esterase strip test may be used as rapid test for diagnosis of spontaneous bacterial peritonitis due to its high diagnostic validity.

Diagnosing bacterial peritonitis made easy by use of leukocyte esterase dipsticks

INTRODUCTION

Spontaneous bacterial peritonitis (SBP) requires rapid diagnosis for the initiation of antibiotics. Its diagnosis is usually based on manual examination of ascitic fluid (AF) having long reporting time. AF infection is diagnosed when the fluid polymorphonuclear leukocyte (PMNL) concentration ≥250 cells/mm(3).

AIMS AND OBJECTIVES

Aim was to evaluate the diagnostic utility of leukocyte esterase (LE) reagent strip for rapid diagnosis of SBP in patients who underwent abdominal paracentesis and to calculate the sensitivity, specificity, positive, and negative predictive values.

MATERIALS AND METHODS

The study was carried out on 103 patients with ascites. Cell count of AF as determined by colorimetric scale of Multistix 10 SG reagent strip was compared with counting chamber method (PMNL count ≥250 cells/mm(3) was considered positive).

RESULTS AND OBSERVATIONS

Of the 103 patients SBP was diagnosed in 20 patients, 83 patients were negative for SBP by manual cell count. The sensitivity and specificity of the LE test for detecting neutrocytic SBP taking grade 2 as cut off were 95% and 96.4% respectively, with a positive predictive value of 86.4% and a negative predictive value of 98.8%. Diagnostic accuracy of LE test was 96.1%.

DISCUSSION

There was a good correlation between the reagent strip result and PMNL count. The LE strip test is based on the esterase activity of activated granulocytes which reacts with an ester-releasing hydroxyphenylpyrrole causing a colour change in the azo dye of reagent strip. It is a very sensitive and specific method for the prompt detection of elevated PMNL count, and represents a convenient, inexpensive, simple, and bedside method for diagnosis of SBP. A negative LE test result excludes SBP with a high degree of certainty.

Pleural, peritoneal and pericardial effusions - a biochemical approach

The pathological accumulation of serous fluids in the pleural, peritoneal and pericardial space occurs in a variety of conditions. Since patient management depends on right and timely diagnosis, biochemical analysis of extravascular body fluids is considered a valuable tool in the patient management process. The biochemical evaluation of serous fluids includes the determination of gross appearance, differentiation of transudative from exudative effusions and additional specific biochemical testing to assess the effusion etiology. This article summarized data from the most relevant literature concerning practice with special emphasis on usefulness of biochemical tests used for the investigation of pleural, peritoneal and pericardial effusions. Additionally, preanalytical issues concerning serous fluid analysis were addressed and recommendations concerning acceptable analytical practice in serous fluid analysis were presented.

Measurement of calprotectin in ascitic fluid to identify elevated polymorphonuclear cell count

AIM: To evaluate the diagnostic capability of calprotectin in ascitic fluid for detecting a polymorphonuclear (PMN) cell count > 250/μL ascites.

METHODS: In this prospective observational study, a total of 130 ascites samples were analysed from 71 consecutive patients referred for paracentesis. Total and differential leukocyte cell counts were determined manually with a Neubauer chamber and gentian-violet stain. Calprotectin was measured in 1 mL ascetic fluid by enzyme-linked immunosorbent assay (ELISA) and a point-of-care (POC) lateral flow assay with the Quantum Blue^® Reader (Bühlmann Laboratories). All measurements were carried out in a central laboratory by senior personnel blinded to patient history. A PMN count > 250/μL was the primary endpoint of the study. The diagnostic value of ascitic calprotectin measurement was assessed by comparing to the final diagnosis of each patient that had been adjudicated by investigators blinded to calprotectin values.

RESULTS: The PMN count was > 250/μL in 19 samples (14.6%) from 15 patients (21.1%) and varied widely among the study population (range 10-19 800/mL and 1-17 820/mL, respectively). Spontaneous bacterial peritonitis (SBP) was the final diagnosis in four patients (5.6%). All patients with PMN ≤ 250/μL had negative bacterial culture. PMN count was elevated in five patients with peritoneal carcinomatosis, three with lymphoma, one with neuroendocrine carcinoma, and two with secondary peritonitis due to abdominal perforation. PMN cell counts correlated with ascitic calprotectin values (Spearman’s rho; r = 0.457 for ELISA, r = 0.473 for POC). A considerable range of ascitic calprotectin concentrations was detected by ELISA [median 0.43 μg/mL, interquartile range (IQR) 0.23-1.23 (range 0.10-14.93)] and POC [median 0.38 μg/mL, IQR 0.38-0.56 (range 0.38-13.31)]. Ascitic calprotectin levels were higher in samples with PMN > 250/μL, by both ELISA [median (IQR) 2.48 μg/mL (1.61-3.65) vs 0.10 μg/mL (0.10-0.36), P < 0.001] and POC [2.78 μg/mL (2.05-5.37) vs 0.38 μg/mL (0.38-0.41), P < 0.001]. The area under the receiver operating characteristics curve for identifying an elevated PMN count was 0.977 (95%CI: 0.933 to 0.995) for ELISA and 0.982 (95%CI: 0.942 to 0.997) for POC (P = 0.246 vs ELISA). Using the optimal cut-off value for ELISA (0.63 μg/mL), ascitic calprotectin had 94.8% sensitivity, 89.2% specificity, positive and negative likelihood ratios of 8.76 and 0.06 respectively, positive and negative predictive values of 60.0% and 99.0% respectively, and 90.0% overall accuracy. Using the optimal cut-off value for POC (0.51 μg/mL), the respective values were 100.0%, 84.7%, 6.53, 0.00, 52.8%, 100% and 87.7%. Correlation between ELISA and POC was excellent (r = 0.873, P < 0.001). The mean ± SD of the difference was -0.11 ± 0.48 μg/mL with limits of agreement of + 0.8 μg/mL (95%CI: 0.69 to 0.98) and -1.1 μg/mL (95%CI: -1.19 to -0.91).

CONCLUSION: Ascitic calprotectin reliably predicts PMN count > 250/μL, which may prove useful in the diagnosis of SBP, especially with a readily available bedside testing device.

Clinical impression and ascites appearance do not rule out bacterial peritonitis

BACKGROUND

Previous research has demonstrated that physician clinical suspicion, determined without assessing fluid appearance, is not adequate to rule out spontaneous bacterial peritonitis (SBP) without fluid testing.

STUDY OBJECTIVE

To determine the sensitivity of physician clinical suspicion, including a bedside assessment of fluid appearance, in the detection of SBP in Emergency Department (ED) patients undergoing paracentesis.

METHODS

We conducted a prospective, observational study of ED patients with ascites undergoing paracentesis at three academic facilities. The enrolling physician recorded the clinical suspicion of SBP ("none," "low," "moderate," or "high"), and ascites appearance ("clear," "hazy," "cloudy," or "bloody"). SBP was defined as an absolute neutrophil count ≥ 250 cells/mm(3), or culture pathogen growth. We defined "clear" ascites fluid as negative for SBP, and "hazy," "cloudy," or "bloody" as positive. A physician clinical suspicion of "none" or "low" was considered negative for SBP, and an assessment of "moderate" or "high" was considered positive. The primary outcome measure was sensitivity of physician clinical impression and ascites appearance for SBP.

RESULTS

There were 348 cases enrolled, with SBP diagnosed in 43 (12%). Physician clinical suspicion had a sensitivity of 42% (95% confidence interval [CI] 29-55%) for the detection of SBP. Fluid appearance had a sensitivity of 72% (95% CI 58-83%).

CONCLUSION

Physician clinical impression, which included an assessment of fluid appearance, had poor sensitivity for the detection of SBP and cannot be used to exclude the diagnosis. Routine laboratory fluid analysis is indicated after ED paracentesis, even in patients considered to have a low degree of suspicion for SBP.

Multistix 10 SG Leukocyte Esterage Dipstick Testing in Rapid Bedside Diagnosis of Spontaneous Bacterial Peritonitis: A Prospective Study

BACKGROUND AND AIMS

Spontaneous bacterial peritonitis (SBP) requires rapid diagnosis and the initiation of antibiotics. Diagnosis of SBP is usually based on cytobacteriological examination of ascitic fluid. These tests require good laboratory facilities and reporting time of few hours to 1-2 day. However, the 24 h laboratory facilities not widely available in country like India. We evaluated the diagnostic utility of reagent strip (Multistix 10 SG(®)) for rapid diagnosis of SBP.

MATERIAL AND METHODS

The study was prospectively carried out on patients of cirrhosis with ascites. Bedside leukocyte esterase reagent strip testing was performed on ascitic fluid. Cell count as determined by colorimetric scale of reagent strip was compared with counting chamber method. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were calculated.

RESULT

Out of 100 patients with cirrhotic ascites, [72 males: 28 female; mean age 44.34 (SD 13.03) years] 18 patients were diagnosed to have SBP by counting chamber method as compared to 14 patients detected to have SBP by reagent strip test ≥++ positive. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of reagent strip ≥++ positive were 77.77%, 95.12%, 77.77%, 95.12% and 92% respectively compared to counting chamber method.

CONCLUSION

Reagent strip to diagnose SBP is very specific but less sensitive as compared to counting chamber method. This can be performed rapidly, easily and efficiently even in remote area of developing countries. This bedside test could be a useful tool for the diagnosis of SBP in country like India.

Spontaneous bacterial peritonitis: How to deal with this life-threatening cirrhosis complication?

Spontaneous bacterial peritonitis (SBP) is one of the most common and life-threatening complications of cirrhosis. It occurs in 10% to 30% of patients admitted to hospital and recent studies tend to demonstrate that SBP incidence seems to be decreasing in its frequency. A bacterial overgrowth with translocation through the increased permeable small intestinal wall and impaired defense mechanisms is considered to be the main mechanism associated with its occurrence. The Gram-negative aerobic bacteria are the major responsible for SBP episodes and Gram-positive bacteria, mainly Staphylococcus aureus, are being considered an emergent agent causing SBP. The prompt diagnosis of SBP is the key factor for reduction observed in mortality rates in recent years. The clinical diagnosis of SBP is neither sensitive nor specific and the search for new practical and available tools for a rapid diagnosis of SBP is an important endpoint of current studies. Reagent strips were considered a promising and faster way of SBP diagnosis. The prompt use of empirical antibiotics, mostly cefotaxime, improves significantly the short-term prognosis of cirrhotic patients with SBP. The recurrence rate of SBP is high and antibiotic prophylaxis has been recommended in high-risk settings. Unfortunately, the long-term prognosis remains poor.

Diagnosis of spontaneous bacterial peritonitis: An update on leucocyte esterase reagent strips

Ascites remain the commonest complication of decompensated cirrhosis. Spontaneous bacterial peritonitis (SBP) is defined as the infection of ascitic fluid (AF) in the absence of a contiguous source of infection and/or an intra-abdominal inflammatory focus. An AF polymorphonuclear (PMN) leucocyte count ≥ 250/mm³ -irrespective of the AF culture result- is universally accepted nowadays as the best surrogate marker for diagnosing SBP. Frequently the results of the manual or automated PMN count do not reach the hands of the responsible medical personnel in a timely manner. However, this is a crucial step in SBP management. Since 2000, 26 studies (most of them published as full papers) have checked the validity of using leukocyte esterase reagent strips (LERS) in SBP diagnosis. LERS appear to have low sensitivity for SBP, some LERS types more than others. On the other hand, though, LERS have consistently given a high negative predictive value (> 95% in the majority of the studies) and this supports the use of LERS as a preliminary screening tool for SBP diagnosis. Finally, an AF-tailored dipstick has been developed. Within the proper setting, it is set to become the mainstream process for handling AF samples.

Prevention and management of bacterial infections in cirrhosis

Patients with cirrhosis of liver are at risk of developing serious bacterial infections due to altered immune defenses. Despite the widespread use of broad spectrum antibiotics, bacterial infection is responsible for up to a quarter of the deaths of patients with liver disease. Cirrhotic patients with gastrointestinal bleed have a considerably higher incidence of bacterial infections particularly spontaneous bacterial peritonitis. High index of suspicion is required to identify infections at an early stage in the absence of classical signs and symptoms. Energetic use of antibacterial treatment and supportive care has decreased the morbidity and mortality over the years; however, use of antibiotics has to be judicious, as their indiscriminate use can lead to antibiotic resistance with potentially disastrous consequences. Preventive strategies are still in evolution and involve use of antibiotic prophylaxis in patients with gastrointestinal bleeding and spontaneous bacterial infections and selective decontamination of the gut and oropharynx.

A new highly sensitive point of care screen for spontaneous bacterial peritonitis using the leukocyte esterase method

BACKGROUND & AIMS

Urine reagent strips measuring leukocyte esterase activity have been studied to screen spontaneous bacterial peritonitis (SBP) but are insensitive. We calibrated a strip specifically for ascitic fluid to achieve high sensitivity in this diagnosis.

METHODS

Experiments were conducted on ascitic fluid from patients with cirrhosis. Samples with SBP were diluted with native acellular ascitic fluid to achieve PMN counts below, above, and close to the diagnostic threshold of 250 PMN/microl. A model of SBP was created by spiking negative ascitic fluid samples (<250 PMN/microl) with activated PMN from blood of patients with sepsis, and diluted to achieve a range of PMN. Aliquots were tested at 2, 3, 4, and 10 min with the Periscreen leukocyte esterase strip. PMN/microl was correlated to timings and color scales: white defined negative (PMN <250/microl); and shades of brown, purple, and pink defined positive. Ascitic fluid samples were obtained from 58 patients. Negative ascitic fluid was used from 32 to generate the model SBP.

RESULTS

One thousand three hundred and four experiments were performed with a median PMN count of 492/microl (0-7510). After exclusion of uninterpretable colorimetric results, 1089 experiments were analyzed [PMN of 444/microl (0-7510)]. The best result was obtained at 3 min (n=299), with Se: 100%, Sp: 57.9%; NPV: 100%, PPV: 76.5%. The test was not interpretable in bloody, chylous or bilious ascitic fluid, or concurrent imipenem treatment.

CONCLUSIONS

This new leukocyte esterase strip calibrated to an ascitic fluid PMN count 250/microl is a robust screening tool when the strip turns any hue of tan/brown at 3 min.

Biochemical analysis of ascitic (peritoneal) fluid: what should we measure?

Ascitic fluid samples are frequently sent to the laboratory for analysis. Although the underlying cause of the ascites is often thought to be clinically obvious, it is important to establish a definitive diagnosis. The value of a cell count and bacterial culture of the ascitic fluid is not disputed, but the role of biochemical testing is less clear. The use of ascitic fluid total protein to try to classify ascitic fluids as either an exudate or a transudate has contributed to this. The use of the physiologically based serum ascites albumin gradient to differentiate ascites caused by portal hypertension from other causes provides a better diagnostic approach. We recommend that the serum ascites albumin gradient is performed by laboratories as the first-line test and that interpretative reports are provided. Additional testing should be restricted to specific diagnostic queries and requires close collaboration between the laboratory and the clinician.

Current status of liver diseases in Korea: liver cirrhosis

Liver cirrhosis represents the final common pathway of virtually all chronic liver diseases, and is characterized by an accumulation of extracellular matrix rich in fibrillar collagens. Patients with cirrhosis are at risk of developing many potential complications. The most common complication seen in patients with liver cirrhosis is ascites, and the most lethal one is bleeding varices. Other intermediate and late stage complications include spontaneous bacterial peritonitis, hepatic encephalopathy, and hepatorenal syndrome. The mortality and morbidity attributable to liver disease in Korea have decreased continuously over the past decades, probably due to the implementation of universal vaccination and potent antiviral therapies. In addition, recent advances in the understanding of the pathophysiology of cirrhosis and in various management approaches to cirrhosis complications will contribute to the steady improvement in patient outcomes in this country. This review article outlines recent changes in etiologies and prognosis, and the advances in management of cirrhosis in Korea.

A comparison of diagnostic efficacies among different reagent strips and automated cell count in spontaneous bacterial peritonitis

BACKGROUND

Currently, decision to give antibiotics in spontaneous bacterial peritonitis (SBP) suspected patient depends mainly on the result of manual cell count, which requires significant waiting period. Recently, many reports on the efficacies of reagent strips and a few reports of automated cell count are available but there has been no direct comparison study.

AIMS

This prospective study was to assess the diagnostic efficacies of different reagent strips (Aution, Multistix, Combur) and automated cell count.

METHODS AND RESULTS

A total of 250 paracenteses were performed. There were 40 specimens obtained from patients with clinical suspicion for SBP, the rest were obtained from non SBP suspected patients. Thirty specimens from 250 samples (12%) were diagnosed as SBP by manual cell count. Automated system provided higher value for SBP diagnosis in all parameters (sensitivity, specificity, PPV, NPV, and accuracy; 87.5-99.1%) whereas the strip tests provided lower number in all parameters (80-98.6%). Multistix provided the lowest sensitivity (80%). The false negative rates by Aution, Multistix, Combur tests and automated cell count were 10%, 20%, 10% and 3.3%, respectively. By lowering the cut off for SBP diagnosis with the automated system to 200 cells/mm(3), there was no false negative.

CONCLUSIONS

Comparing to reagent strips, automated cell count is a better screening tool for SBP diagnosis because it provides higher validity scores and a lower false negative rate. However, the discrepancy of cell count reading may occur, we suggest using a lower cut off for SBP diagnosis by the automated system.

Evaluation of leucocyte esterase reagent strip test for the rapid bedside diagnosis of spontaneous bacterial peritonitis

BACKGROUND

Spontaneous bacterial peritonitis (SBP) is a common serious complication of cirrhosis, and carries a high morbidity and mortality. Rapid diagnosis and prompt treatment of this condition may improve survival of such patients.

OBJECTIVE

To validate the diagnostic efficacy of a leukocyte esterase reagent (LER) strip test for rapid, bedside diagnosis of SBP.

METHODS

We prospectively studied 175 patients with liver cirrhosis and ascites [mean age 48 (SD 16.4) years; 146 men] between August 2007 and December 2008. Alcohol was the most common (124 of 175; 70.8%) cause of liver cirrhosis. All patients underwent abdominal paracentesis, and the ascitic fluid was processed for cell count, LER strip (Magistik 10) test and culture. Two different cut-offs for calling the LER strip test positive were tried, namely when the color turned light blue [grade 2: >125 polymorphonuclear leucocytes (PMNL)/microL] or it turned purple (grade 3: >500 PMNL/microL). Sensitivity, specificity, positive predictive value, negative predictive value were calculated, using PMN count by microscopy exceeding 250 PMNL/microL.

RESULTS

LER strip using the more stringent purple-color cut off to diagnose SBP had a sensitivity of 92% and specificity of 100%. The corresponding figures using the light-blue color cut-off were 97% and 89%, respectively.

CONCLUSIONS

LER strip testing of ascitic fluid is a rapid, cheap and sensitive bed side tool for the diagnosis of SBP.

Ascites and spontaneous bacterial peritonitis: an Asian perspective

Ascites is the most common complication of liver cirrhosis, and it develops as a consequence of portal hypertension and splanchnic vasodilatation. Depending on severity, management of ascites consists of diverse strategy, including dietary sodium restriction, diuretic therapy, repeated large-volume paracentesis with albumin infusion, transjugular intrahepatic portosystemic shunt, and liver transplantation. Recently, advances in medical therapy have been made with satavaptan, a V2 receptor antagonist, vasoconstrictors, such as clonidine, midodrine, or terlipressin, and other categories of drugs, including docarpamine and Chinese herbs. These drugs may serve as useful adjuncts to conventional diuretics in the management of ascites. Besides ascites itself, serious complications, such as spontaneous bacterial peritonitis (SBP) and hepatorenal syndrome, frequently ensue in decompensated cirrhosis. SBP develops from the translocation of bacteria from the intestine, and successful management with early diagnosis and treatment with proper prevention in patients of high risk is necessary. In summary, ascites is a starting point for more serious complications in liver cirrhosis. Although liver transplantation is the fundamental treatment, it is not always feasible, and consequently various means of treatment should be used. Further study, particularly in Asia where hepatitis B virus-related cirrhosis is predominant, is warranted to improve the clinical outcome.

Ascitic fluid analysis for diagnosis and monitoring of spontaneous bacterial peritonitis

Polymorphonuclear (PMN) cell count in the ascitic fluid is essential for the diagnosis and management of spontaneous bacterial peritonitis (SBP). To date, PMN cell count is routinely performed by traditional manual counting. However, this method is time-consuming, costly, and not always timely available. Therefore, considerable efforts have been made in recent years to develop an alternative test for a more rapid diagnosis and monitoring of SBP. The use of urinary reagent strips was proposed to achieve an “instant” bedside diagnosis of SBP. A series of reports evaluated the urine strip test for SBP diagnosis and reported promising results. However, a recent large multicenter study revealed a surprising lack of diagnostic efficacy of the urine screening test for SBP diagnosis. Another method, more recently proposed as an alternative to the manual PMN count, is the measurement of lactoferrin in ascitic fluid, but the data available on the diagnostic value of this test are limited to a single study. However, both urinary reagent strips and ascitic lactoferrin tests are qualitative methods and need, therefore, to be further confirmed by standard cytology of the ascitic fluid. To date, the only quantitative method proposed as a valid alternative to manual PMN counting is automated blood cell counters, commonly used in all laboratories for blood cell counting. Data available in the literature on the diagnostic performance of this method are limited but very promising, and this tool seems to have the potential to replace the manual counting method.

Is there yet any place for reagent strips in diagnosing spontaneous bacterial peritonitis in cirrhotic patients? An accuracy and cost-effectiveness study in Brazil

BACKGROUND

Diagnosis of spontaneous bacterial peritonitis (SBP) is currently based on ascitic cell counting, but there is a need for a more simple and rapid diagnostic tool. The objectives of this study are to evaluate the accuracy of reagent strips in diagnosing SBP and compare their costs with total and differential cell counts.

PATIENTS AND METHODS

71 cirrhotic in- and outpatients were consecutively included (159 samples). Spontaneous bacterial peritonitis was defined as neutrophil cells >or= 250/microL. The cutoff values for each reagent strip were defined by a receiver operating characteristic (ROC) curve. Sensitivity (S), Specificity (Sp), Positive and Negative Predictive Values (PPV and NPV), Accuracy (Ac) and cost-effectiveness (US$) in comparison to cell count exam were calculated.

RESULTS

Spontaneous bacterial peritonitis was diagnosed in 17 patients (23.9%), 11 of them with positive culture (64.7%). The best cutoff points found in ROC curves were 1+ for Multistix 10 SG and ca. 75 for Choiceline 10 (Multistix 10 SG S = 80%, Sp = 98.5%, PPV = 90.9%, NPV = 96.2%, Ac = 95%; Choiceline 10 S = 76.9%, Sp = 97.7%, PPV = 87%, NPV = 95.6%, Ac = 94%). In terms of cost-effectiveness by cost/accuracy, cell count was 41.5, Multistix 10 SG 0.57, and Choiceline 10, 0.19 (P < 0.001).

CONCLUSION

Reagent strips are a useful tool for diagnosing SBP in cirrhotic patients, but they have some limitations. Strips are especially indicated when total and differential cell counts are not quickly available or sometimes unavailable. They are also indicated as screening test in emergency rooms to anticipate the diagnosis of SBP and allow its early treatment. It's an interesting option in developing countries.

Leucocyte esterase reagent strips for the diagnosis of spontaneous bacterial peritonitis: a systematic review

The reported incidence of spontaneous bacterial peritonitis (SBP) is 7-30% per annum in cirrhotic patients. Timely diagnosis and treatment is crucial to reduce mortality owing to this infection. Recently, leucocyte esterase reagent strips have been tested in the diagnosis of infection in the ascitic fluid. The objective was to evaluate the diagnostic value of leucocyte esterase reagent strips in SBP in cirrhotic patients with ascites, by systematically reviewing the evidence from prospective clinical studies. We performed a comprehensive literature search in Medline up to July 2007 for adult human prospective clinical studies. Two reviewers independently checked all identified studies for fulfillment of predefined inclusion criteria, extracted data and assessed methodological quality of included studies. We had decided a priori to pool the studies via meta-analysis, only if statistical heterogeneity was found to be nonsignificant (P>0.10). Seventeen studies were included. Statistical heterogeneity among studies was found to be highly significant (P<0.001) in all analyses, precluding pooling of data for meta-analysis. Compared with the manual polymorphonuclear count ('gold standard'), leucocyte esterase reagent strips were found to have sensitivity ranging from 45 to 100%, specificity ranging from 81 to 100%, positive predictive value ranging from 42 to 100% and negative predictive value ranging from 87 to 100%. Despite the wide variation in sensitivity and positive predictive value between studies, the consistently high negative predictive value of leucocyte esterase reagent strips in SBP diagnosis should gain it a place in the ascitic tap diagnostic algorithm.

Accuracy of the automated cell counters for management of spontaneous bacterial peritonitis

AIM: To evaluate the accuracy of automated blood cell counters for ascitic polymorphonuclear (PMN) determination for: (1) diagnosis, (2) efficacy of the ongoing antibiotic therapy, and (3) resolution of spontaneous bacterial peritonitis (SBP).

METHODS: One hundred and twelve ascitic fluid samples were collected from 52 consecutive cirrhotic patients, 16 of them with SBP. The agreement between the manual and the automated method for PMN count was assessed. The sensitivity/specificity and the positive/negative predictive value of the automated blood cell counter were also calculated by considering the manual method as the “gold standard”.

RESULTS: The mean ± SD of the difference between manual and automated measurements was 7.8 ± 58 cells/mm³, while the limits of agreement were +124 cells/mm³ [95% confidence interval (CI): +145 to +103] and -108 cells/mm³ (95% CI: -87 to -129). The automated cell counter had a sensitivity of 100% and a specificity of 97.7% in diagnosing SBP, and a sensitivity of 91% and a specificity of 100% for the efficacy of the ongoing antibiotic therapy. The two methods showed a complete agreement for the resolution of infection.

CONCLUSION: Automated cell counters not only have a good diagnostic accuracy, but are also very effective in monitoring the antibiotic treatment in patients with SBP. Because of their quicker performance, they should replace the manual counting for PMN determination in the ascitic fluid of patients with SBP.

Review article: the utility of reagent strips in the diagnosis of infected ascites in cirrhotic patients

BACKGROUND

Spontaneous bacterial peritonitis (SBP) can be diagnosed via leucocyte esterase reagent strips, although diagnostic performances vary.

AIM

To perform critical review of literature on the use of reagent strips in SBP.

METHODS

Nineteen studies were analysed (Medline search), comparing reagent strips in cirrhotic ascites vs. cytobacteriological methods. Diagnostic grades (G) were: GO = 0 leucocytes/mm3; G1 = 15; G2 = 70; G3 = 125; G4 = 500 for Multistix, GO = 0; G1 = 25; G2 = 75; G3 = 500 for Nephur, Combur, UriScan, and GO = 0; G1 = 25; G2 = 75; G3 = 250; G4 = 500 for Aution.

RESULTS

Medians per study were: 75 patients (range: 31-1041), 136 ascites (47-2123), 17 SBP (5-117). For Multistix (12 studies), the sensitivities fell within the ranges 64.7-100% (G > or = 1), 45.7-83% (G > or = 2) and 45.3-89% (G > or = 3). For Nephur (n = 2), Combur (n = 6), UriScan (n = 1), sensitivities ranged 80.4-100% (G > or = 1), 63-100% (G > or = 2) and 67.7-97% (G > or = 3). For Aution (n = 3), sensitivities ranged 93-96% (G > or = 2) and 89% (G > or = 3). Nephur, Combur, UriScan displayed higher sensitivities than Multistix. However, in larger studies, sensitivities dramatically fell at 45.3% for Multistix (G > or = 3) if ascites polymorphonuclear count <1000/mm3 and 22.2% for bacterascites or 16.7-25% for asymptomatic patients.

CONCLUSION

Use of reagent strips for the diagnosis of SBP cannot be recommended, in view of low sensitivity and a high risk of false negatives, especially in patients with SBP and low polymorphonuclear count.

Spontaneous bacterial peritonitis

Spontaneous bacterial peritonitis (SBP) is the infection of ascitic fluid in the absence of any intra-abdominal, surgically treatable source of infection. Despite timely diagnosis and treatment its reported incidence in ascitic patients varies between 7-30%. Ascitic paracentesis remains the chief diagnostic procedure. Automated cell counters have the same diagnostic accuracy as the manual measurement of white cells. Lately, the use of leucocyte reagent strips (dipsticks) has emerged as a useful alternative. Examination of the fluid is not complete unless the sample is inoculated in blood culture bottles. Treatment is currently with third-generation cephalosporins or oral quinolones. Following a single episode of SBP patients should have long term antibiotic prophylaxis.

Bedside leucocyte esterase reagent strips with spectrophotometric analysis to rapidly exclude spontaneous bacterial peritonitis: a pilot study

BACKGROUND

Spontaneous bacterial peritonitis, a potentially fatal complication of cirrhotic ascites, is diagnosed when the polymorphonuclear leucocyte count in the ascitic fluid is>250/mm. Manual laboratory counting of ascitic polymorphonuclear leucocytes is, however, labour-intensive, costly, results in diagnostic delay and it is not available in all hospitals as part of the 'out-of-hours' service. Thus, a rapid diagnostic screening test for spontaneous bacterial peritonitis would be beneficial in this condition. An exciting new development in the diagnosis of spontaneous bacterial peritonitis is the use of bedside reagent strips; yet, concerns regarding the inherent subjectivity of result reading have prevented the widespread adoption of this technique in clinical practice.

OBJECTIVE

To evaluate the combined use of a leucocyte esterase strip together with an objective portable spectrophotometric reading device in the diagnosis of spontaneous bacterial peritonitis when compared with standard manual laboratory polymorphonuclear leucocyte counting.

METHODS

Nonselected cirrhotic patients undergoing diagnostic paracentesis had an ascitic sample sent for a conventional polymorphonuclear leucocyte count, Gram stain and culture. In addition, a sample was tested with a bedside Multistix 10SG reagent strip and the result was analysed by the Clinitek Status. The strip test was considered positive if it read anything other than negative (i.e. 'trace', '+1', '+2' or '+3').

RESULTS

The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of the reagent strips to diagnose correctly spontaneous bacterial peritonitis when compared with the manual laboratory polymorphonuclear leucocyte count were 100, 91, 50, 100 and 92%, respectively.

CONCLUSIONS

Bedside leucocyte esterase strips, spectrophotometrically read, can reliably exclude spontaneous bacterial peritonitis in patients with cirrhotic ascites. In our series, a negative strip result effectively ruled out this important condition, and suggests that the requirement for manual polymorphonuclear leucocyte counting in this setting could be removed.

Prevention and treatment of infections in patients with cirrhosis

Patients with cirrhosis have altered immune defenses and are considered immunocompromised individuals. Changes in gut motility, mucosal defense and microflora allow for translocation of enteric bacteria into mesenteric lymph nodes and the blood stream. Additionally, the cirrhotic liver is ineffective at clearing bacteria and associated endotoxins from the blood thus allowing for seeding of the sterile peritoneal fluid. Thus, hospitalised cirrhotic patients, particularly those with gastrointestinal hemorrhage, are at high risk of developing bacterial infections, the most common being spontaneous bacterial peritonitis. Given the significant morbidity and mortality associated with spontaneous bacterial peritonitis and the fact that half of the cases are community acquired, all hospitalised cirrhotic patients should have a diagnostic paracentesis to exclude infection. Those admitted with gastrointestinal bleed and a negative paracentesis require short-term prophylaxis with norfloxacin. A third generation cephalosporin is the treatment of choice for spontaneous bacterial peritonitis and, once the acute infection is resolved, secondary prophylaxis with oral norfloxacin is warranted. Patients who develop renal dysfunction at the time of active infection have the highest mortality and require adjunctive albumin therapy. This article reviews the pathogenesis of SBP, the evidence behind the antibiotics used, the rationale for adjunctive albumin therapy in the setting of acute renal failure, and the role of prophylactic antibiotics in specific high-risk populations.

Efficacy of leukocyte esterase dipstick test as a rapid test in diagnosis of spontaneous bacterial peritonitis

AIM: To evaluate the efficacy of dipstick test in diagnosis of spontaneous bacterial peritonitis (SBP) in cirrhotic patients who underwent abdominal paracentesis based on the locally available dipstick test.

METHODS: There were 200 consecutive samples from cirrhotic patients who underwent abdominal paracentesis. Urine dipstick (Combur¹⁰ Test^®M, Roche, Mannheim, Germany) was used as a screening test. A manual cell count with differential study was done in all samples by experienced technicians. The polymorphonuclear (PMN) cell count more than 250 cells/mm³ was used as a diagnostic cut off level. One to three plus dipstick results were used as cut off levels for a positive result. The dipstick test results had to be agreed by three experienced readers. The sensitivity, specificity, positive and negative predictive values and accuracy of two different colorimetric cut off scales (1+ and 2+) were calculated and compared.

RESULTS: The prevalence of SBP diagnosed by manual cell count was 21.0%. There were 128 specimens that had a true negative result by dipstick. The sensitivity, specificity, positive and negative predictive values and accuracy of 1+ and 2+ cut off scale to diagnose SBP were 88%, 81%, 55%, 96% and 83% respectively, and 63%, 96%, 82%, 81% and 89% respectively.

CONCLUSION: Dipstick test can be used as a rapid test for screening of SBP. The higher cut off colorimetric scale has a better specificity and positive predictive value but a lower sensitivity.