Rapid Bedside Test Research Articles

About one-half of early spontaneous preterm deliveries can be identified by a rapid matrix metalloproteinase-8 (MMP-8) bedside test at the time of mid-trimester genetic amniocentesis*

Objective: Mid-trimester amniocentesis continues to be used for the prenatal diagnosis of chromosomal anomalies and other genetic disorders. Analysis of amniotic fluid obtained at the time of mid-trimester genetic amniocentesis identifies those patients who are at risk for early spontaneous preterm delivery. This is based on a solid body of evidence that found subclinical intra-amniotic inflammation/infection to be causally linked to early spontaneous preterm birth. Although several biomarkers have been proposed to identify intra-amniotic inflammation, the accumulated data suggest that the determination of amniotic fluid matrix metalloproteinase-8 (MMP-8), or neutrophil collagenase, is a powerful predictor of spontaneous preterm delivery. MMP-8 is released by inflammatory cells in response to microbial products or “danger signals”. A rapid point-of-care test has been developed to determine MMP-8 at the bedside within 20 min, and without the requirement of laboratory equipment. The objective of this study was to determine whether an elevation of MMP-8 in the amniotic fluid, measured by a rapid point-of-care test, can identify those patients at risk for spontaneous preterm delivery after a mid-trimester genetic amniocentesis. Study design: A case–control study was designed to obtain amniotic fluid from asymptomatic singleton pregnant women who underwent mid-trimester genetic amniocentesis. An MMP-8 bedside test was performed to analyze the amniotic fluid of 64 patients with early spontaneous preterm delivery (<30 weeks) and 128 matched controls with normal pregnancy outcomes. Results: (1) The MMP-8 bedside test (Yoon's MMP-8 Check™) was positive in 42.2% (27/64) of patients with spontaneous preterm delivery but in none (0/128) of the control cases (p < 0.001); (2) the MMP-8 bedside test had a sensitivity of 42.2%, and a specificity of 100% in the prediction of spontaneous preterm delivery (<30 weeks) following a mid-trimester genetic amniocentesis; and (3) among the patients with spontaneous preterm delivery, those with a positive MMP-8 bedside test had a significantly higher rate of spontaneous delivery within 2 weeks and 4 weeks of an amniocentesis [40.7% (11/27) versus 5.4% (2/37); 63.0% (17/27) versus 24.3% (9/37)] and a shorter interval-to-delivery period than those with a negative test [interval-to-delivery: median (range), 16 d (0–95 d) versus 42 d (2–91 d); p < 0.05 for each]. Conclusion: We conclude that 42% of patients with an early spontaneous preterm delivery (< 30 weeks) could be identified by a rapid MMP-8 bedside test at the time of their mid-trimester genetic amniocentesis. The MMP-8 bedside test is a powerful predictor of early spontaneous preterm birth in asymptomatic pregnant women.

A rapid interleukin-6 bedside test for the identification of intra-amniotic inflammation in preterm labor with intact membranes

Objective: Preterm birth is associated with 5–18% of pregnancies and is the leading cause of neonatal morbidity and mortality. Amniotic fluid (AF) interleukin-6 (IL-6) is a key cytokine for the identification of intra-amniotic inflammation, and patients with an elevated AF IL-6 are at risk for impending preterm delivery. However, results of the conventional method of measurement (enzyme-linked immunosorbent assay; ELISA) are usually not available in time to inform care. The objective of this study was to determine whether a point of care (POC) test or lateral-flow-based immunoassay for measurement of AF IL-6 concentrations can identify patients with intra-amniotic inflammation and/or infection and those destined to deliver spontaneously before term among women with preterm labor and intact membranes.Methods: One-hundred thirty-six women with singleton pregnancies who presented with symptoms of preterm labor and underwent amniocentesis were included in this study. Amniocentesis was performed at the time of diagnosis of preterm labor. AF Gram stain and AF white blood cell counts were determined. Microbial invasion of the amniotic cavity (MIAC) was defined according to the results of AF culture (aerobic and anaerobic as well as genital mycoplasmas). AF IL-6 concentrations were determined by both lateral flow-based immunoassay and ELISA. The primary outcome was intra-amniotic inflammation, defined as AF ELISA IL-6 ≥ 2600 pg/ml.Results: (1) AF IL-6 concentrations determined by a POC test have high sensitivity (93%), specificity (91%) and a positive likelihood ratio of 10 for the identification of intra-amniotic inflammation by using a threshold of 745 pg/ml; (2) the POC test and ELISA for IL-6 perform similarly in the identification of MIAC, acute inflammatory lesions of placenta and patients at risk of impending spontaneous preterm delivery.Conclusion: A POC AF IL-6 test can identify intra-amniotic inflammation in women who present with preterm labor and intact membranes and those who will subsequently deliver spontaneously before 34 weeks of gestation. Results can be available within 20 min – this has important clinical implications and opens avenues for early diagnosis as well as treatment of intra-amniotic inflammation/infection.

Pupillometric findings in children with obstructive sleep apnea

BackgroundObstructive sleep apnea (OSA) leads to intermittent hypoxia, activation of the sympathetic nervous system, and eventually cardiovascular morbidity. Alterations in autonomic nervous system (ANS) tone and reflexes are likely to play major roles in OSA-associated morbidities, and have been identified in a subset of children with OSA. ObjectivesTo evaluate whether pupillometry, a noninvasive and rapid bedside test for the assessment of autonomic nervous system dysfunction (ANS), would detect abnormal ANS function in children with OSA. MethodsChildren ages 2–12 years underwent polysomnography (PSG), and were divided based on PSG findings into two groups; Habitual Snorers (HS; AHI < 1 h/TST, n = 17) and OSA (AHI > 1 h/TST, n = 49), the latter then sub-divided into AHI severity categories (>1 but <5, >5 but <10, and >10 h/TST). Pupillometric measurements were performed during the clinic visit in a dark room using an automated pupillometer device. ResultsA total of 66 subjects with a mean age of 7.3 ± 2.6 years were recruited. There were no statistically significant differences between any of the groups, even when comparing severe OSA (n = 15) and HS in any of the measures related to pupillary reflexes. However, mild, yet significant increases in systolic blood pressure and morning plasma norepinephrine levels were detected in the severe OSA group. ConclusionAlthough ANS perturbations are clearly present in a proportion of children with OSA, particularly those with severe disease, pupillary responses do not appear to provide a sensitive method for the detection of ANS dysfunction in OSA children.

Rapid bedside tests for diagnosis, management, and prevention of nosocomial influenza

Like other respiratory viruses, influenza is responsible for devastating nosocomial epidemics in nursing homes as well as in conventional wards and emergency departments. Patients, healthcare workers, and visitors may be the source of nosocomial influenza. Despite their limited sensitivity, rapid diagnostic tests for influenza can be of real value; they enable early introduction of measures to prevent spread and early specific antiviral treatment of cases. However, these tests cannot detect oseltamivir resistance, susceptibility testing being carried out only in specialist laboratories. Although resistance is rare, it can emerge during treatment, especially of very young children or immunocompromised patients. In the latter, the shedding of resistant influenza virus can last several weeks. Sporadic instances of nosocomial transmission among immunocompromised patients have been reported. The limitations of bedside tests for influenza make them unsuitable for use as stand-alone diagnostic tools. However, their limitations do not preclude their use for detection and subsequent management of nosocomial influenza, for which they are rapid, easy, and cost-effective. Recent developments in these tests look promising, offering prospects of increased sensitivity, increased specificity, and screening for antiviral susceptibility.

Role of Thoracic Sonographic Scan in Diagnosis of Pneumothorax

Background: Pneumothorax is a common problem seen in patients with acute and chronic medical and traumatic conditions with wide range of clinical presentations ranging from subtle decrease in breath sounds to cardiopulmonary arrest caused by tension pneumothorax. Pneumothorax is traditionally diagnosed by chest radiography, ultrasound is fairly a new modality of diagnosis. Ultrasound is a rapid noninvasive bedside test that may reduce mortality from this pathology by early detection. There are certain sonographic criteria that can exclude or confirm pneumothorax; this work has been performed to analyze these criteria. Patients and Methods: The study was done in Sulaimani teaching hospital and Sulaimani emergency hospital from June 1st to 10th August 2013. We performed thoracic ultrasound on fifty three diagnosed cases of pneumothorax (by chest X-ray &/or thoracic computed tomography). The age of the patients ranged between (10 - 82 years), mean age (38 years), 35 males and 18 females. Lung sliding sign, lung point sign and A line signs were recorded and analyzed. Results: The sensitivity, specificity, positive predictive value and negative predictive values of absent lung sliding sign were: 100%, 94%, 94% and 100% respectively, for lung point sign were: 70%, 100%, 100% and 68% respectively, for A line sign were: 91%, 71%, 73% and 91% respectively, for absent lung sliding and lung point sign together were 70%, 100%, 100% & 68.9% respectively. Conclusion: We confirmed the conclusion of other studies which stated that presence of lung sliding excludes pneumothorax and identification of lung point in a case with absent lung sliding is diagnostic of pneumothorax.

Goal-Directed Coagulation Management in the Perioperative Period of Cardiac Surgery

COAGULOPATHY IS A CONCERN in cardiac surgery that involves cardiopulmonary bypass as it leads to an increased risk of perioperative bleeding and transfusion. Recent advances in coagulation monitoring using point-of-care (POC) devices, and new hemostatic agents have increased interest in using a goal-directed approach to treat coagulopathy. The availability of POC devices in the perioperative setting allows coagulopathy to be assessed using rapid bedside tests. This allows physicians to adopt a goal-directed approach to targeted therapy according to the underlying hemostatic pathology.

PTH-143 Cytosponge instead of Endoscopy in Symptomatic Patients: a Feasibility Study

IntroductionThe estimated annual incidence for oesophageal adenocarcinoma in individuals with Barrett’s oesophagus is 0.2–0.5%1. However, endoscopic screening of individuals with risk factors for Barrett’s oesophagus including chronic heartburn and reflux2...

Comparison of a Rapid Bed-Side Test with a Central Laboratory Analysis for C-Reactive Protein in Newborn Infants with Suspicion of Sepsis

Neonatal sepsis is one of the leading causes of neonatal morbidity and mortality in the newborn period. The purpose of this study was to compare a rapid bed-side test against central laboratory analysis for CRP in newborn infants with suspicion of sepsis. We included 23 newborn infants with suspected or proven sepsis (group 1). Age and gender matched 40 infants without sepsis were assigned as controls (group 2). A total of 116 blood samples (58 samples from each group) were drawn from the peripheral vein for C-reactive protein (CRP) measurements. For the NycoCard CRP tests, 5 microL of whole blood and the same amount of serum was used to determine the CRP value (wCRP-N and sCRP-N). As the reference CRP test, serum concentrations of CRP (CRP-Lab) were simultaneously measured by immunonephelometric method requiring 1 mL of serum sample. CRP values > or = 10 mg/L were considered positive for all three tests. It was found that the median values of wCRP-N (18.9 mg/L), sCRP-N (25 mg/L), and CRP-Lab (22.2 mg/L) of group 1 were higher than group 2 (wCRP-N: 1.1 mg/L, sCRP-N: 5 mg/L, and CRP-Lab: 2.9 mg/L) (p < 0.001). Nycocard-CRP were positively correlated with CRP-Lab. With considering CRP-Lab positive at > 10 mg/L, both CRP-NycoCard tests have high sensitivity and specificity, although sCRP-N has slightly higher predictive values. Passing-Bablok regression and Bland-Altman analysis showed that NycoCard tests have no statistically significant systematic proportional bias. Nycocard-CRP tests have high predictive values, require a very small amount of blood, and results can be obtained quickly. Determinations of CRP concentrations by NycoCard-CRP test seems to be helpful in distinguishing septic and aseptic newborns.

A rapid and accurate new bedside test to assess maximal liver function: a case report

BackgroundIn liver surgery, appropriate preoperative evaluation and preparation of the patient is of cardinal importance. The up-to-date, preoperative prediction of residual liver function has thus far been limited. As post-hepatectomy liver failure is a major cause of mortality, a new and simple bedside test (LiMAx) has been developed to predict postoperative liver function in conjunction with preoperative volumetric analysis of the liver.Case presentationA 45-year-old patient presented with a cecal carcinoma and a large synchronous liver metastasis for major liver surgery. Liver function was determined by the LiMAx-test for the enzymatic capacity of cytochrome P450 1A2, which is ubiquitously and solely active in the liver. A solution of 2 mg/kg body weight 13C-labeled methacetin was injected as a bolus into an intravenous catheter and, thereafter, was metabolized into acetaminophen and 13CO2 and pulmonarily exhaled. The analysis of the 13CO2/12CO2 ratio was performed using online breath sampling over a period of maximally 60 minutes. Based on this test, a value of more than 315 μg/kg/h represents normal liver function. A laparoscopic right hemihepatectomy was planned during virtual resection with a residual liver volume of 48% and a preoperative anticipated residual LiMAx of 301 μg/kg/h. After successful resection, the initial postoperative LiMAx value was 316 μg/kg/h, indicating good liver function and a correct prediction of the outcome.ConclusionIn the presented patient, residual liver function could be accurately predicted preoperatively using a combination of the new LiMax test with CT-volumetry. This test might significantly improve preoperative evaluation and postoperative outcomes in liver surgery.

Whiff Test and Vaginal pH &gt;4.5 as Rapid and Accurate Bed-side Screening Test for Vaginal Infection

Whiff Test and Vaginal pH &gt;4.5 as Rapid and Accurate Bed-side Screening Test for Vaginal Infection

Abstracts: ASUM Annual Scientific Congress 2011

Abstracts: ASUM Annual Scientific Congress 2011

Design and validation of an endothelial progenitor cell capture chip and its application in patients with pulmonary arterial hypertension

The number of circulating endothelial progenitor cells (EPCs) inversely correlates with cardiovascular risk and clinical outcome, and thus has been proposed as a valuable biomarker for risk assessment, disease progression, and response to therapy. However, current strategies for isolation of these rare cells are limited to complex, laborious approaches. The goal of this study was the design and validation of a disposable microfluidic platform capable of selectively capturing and enumerating EPCs directly from human whole blood in healthy and diseased subjects, eliminating sample preprocessing. We then applied the "EPC capture chip" clinically and determined EPC numbers in blood from patients with pulmonary arterial hypertension (PAH). Blood was collected in tubes and injected into polymeric microfluidic chips containing microcolumns pre-coated with anti-CD34 antibody. Captured cells were immunofluorescently stained for the expression of stem and endothelial antigens, identified and counted. The EPC capture chip was validated with conventional flow cytometry counts (r = 0.83). The inter- and intra-day reliability of the microfluidic devices was confirmed at different time points in triplicates over 1-5months. In a cohort of 43 patients with three forms of PAH (idiopathic/heritable, drug-induced, and connective tissue disease), EPC numbers are ≈50% lower in PAH subjects vs. matched controls and inversely related to two potential disease modifiers: body mass index and postmenopausal status. The EPC capture chip (5 × 30 × 0.05mm(3)) requires only 200μL of human blood and has the strong potential to serve as a rapid bedside test for the screening and monitoring of patients with PAH and other proliferative cardiovascular, pulmonary, malignant, and neurodegenerative diseases.

Proteins in leaked amniotic fluid as biomarkers diagnostic for prelabor rupture of membranes

Early diagnosis of prelabor rupture of membranes (PROM) is essential to protect mother and fetus from intra-uterus infection and preterm birth. A simple and rapid bedside test would help clinicians confirm the diagnosis for early treatment. A protein array was used to screen cervical-vaginal fluid (CVF) and amniotic fluid (AF) samples collected from normal and PROM pregnant women. Enzyme-linked immunosorbent assay was used to quantify two novel and potentially useful analytes, soluble intercellular adhesion molecule-1 (sICAM-1) and Axl receptor tyrosine kinase (Axl). The mean concentration of sICAM-1 and Axl was 85 and 482 times higher separately in 30 healthy AF samples than in 110 CVF samples of normal pregnancies. Comparing 110 CVF samples of PROM/Preterm PROM with 110 CVF samples of normal pregnancies, the diagnostic value for PROM was demonstrated by their high sensitivity and specificity (96.4 and 92.7%, respectively, for sICAM-1, and 92.4 and 90.4%, respectively, for Axl). The results indicate that sICAM-1 and Axl in AF leaked to vagina are sensitive and specific biomarkers for the diagnosis of PROM. Furthermore, sICAM-1 or Axl can be developed into a rapid strip test for bedside use.

Platelet aggregation monitoring with a newly developed quartz crystal microbalance system as an alternative to optical platelet aggregometry

The objective of this study was to establish a new test system for the monitoring of platelet aggregation during extracorporeal circulation (ECC) procedures. Even though extensive progress has been made in improving the haemocompatibility of extracorporeal circulation devices, activation of blood coagulation, blood platelets and inflammatory responses are still undesired outcomes of cardiopulmonary bypass. This study deals with an approach towards a platelet aggregation measuring system using a newly developed quartz crystal microbalance (QCM) system. Since QCM is a rarely used technique in the field of blood analytics, the challenge was to transfer the well established methods of aggregometry to the new test system. In a QCM system, either bare gold or fibrinogen-coated sensors were incubated with ADP or arachidonic acid (AA) stimulated platelet rich plasma. For negative controls the GPIIb/IIIa inhibitory antibody abciximab (Reopro®) was used as an inhibitor of platelet aggregation. During incubation, the frequency shifts of the sensors were recorded. The results gained from the QCM system were compared to results gained by optical platelet aggregometry (born aggregometry). For additional visualization of platelet adhesion to the sensor surfaces, fluorescent microscopy and scanning electron microscopy were used. The QCM sensor was able to detect platelet aggregation in both uncoated and fibrinogen coated sensors. The measuring curves of aggregation measurements and controls were clearly distinguishable from each other in terms of frequency shifts and kinetics. For aggregation measurements and inhibited controls the therapeutic diagnosis of platelet function is identical between aggregometer and QCM data. In future, QCM based measuring devices may become an alternative to established point of care methods for rapid bedside testing of platelet aggregation.

The Role of Health Technology Assessment in Vitro Device Development: The Example of Rapid (Bed-Side) Tests for Influenza Assessment

The Role of Health Technology Assessment in Vitro Device Development: The Example of Rapid (Bed-Side) Tests for Influenza Assessment

Reliability of two different bedside assays for C-reactive protein in newborn infants

Bedside tests for C-reactive protein (CRP) have been studied in pediatric patients, but not in neonates. This study compared the results of two rapid bedside tests for CRP (Quick-Read CRP, Orion Diagnostic, Espoo, Finland and NycoCard CRP-Single Test, Axis-Shield, Oslo, Norway) with those of our central laboratory method (CRP-Lab) in newborn infants. CRP concentrations were determined using 72 samples obtained from 43 infants with suspected sepsis occurring between 1 and 28 days of life. Considering positive CRP concentrations to be > or = 10 mg/L, both bedside tests had good specificity (Quick-Read 80.5%, NycoCard 83.3%) and sensitivity (Quick-Read 97.2%, NycoCard 94.4%) when compared with our CRP-Lab. The agreement of measurement with central laboratory values was high for both the bedside tests, without statistically significant differences between the methods. The Quick-Read and NycoCard methods did not show any statistically significant systematic proportional bias when compared with the central laboratory values. The accuracy of the results of both bedside tests is somewhat decreased when CRP concentrations are >100 mg/L. This study shows that both the Quick-Read and the NycoCard test can be used for serial determinations of CRP concentrations in newborn infants. They require small volumes of blood and provide reliable results in < 5 min.

This Month in Gastroenterology

This Month in Gastroenterology

Ascitic Fluid Lactoferrin for Diagnosis of Spontaneous Bacterial Peritonitis

The diagnosis of spontaneous bacterial peritonitis (SBP) is based on a manual count of ascitic fluid polymorphonuclear cells (PMNs). This procedure is operator-dependent and lysis of PMNs during transport to the laboratory may lead to false-negative results. Furthermore, ascitic fluid culture is insensitive and leads to delays in diagnosis. The aim of this study was to assess the utility of ascitic fluid lactoferrin (AFLAC) for the diagnosis of SBP and to identify a cut-off level that can be used for future development of a rapid bedside test. A total of 218 consecutive ascites samples from 148 patients (1-8 samples per patient) with cirrhosis at 2 tertiary care medical centers were examined for PMN count, bedside culture, and lactoferrin concentration. AFLAC concentrations were determined using a polyclonal antibody-based enzyme-linked immunosorbent assay. An ascitic fluid PMN count of 250 cells/mL or greater with or without a positive culture was used for diagnosis of SBP. Twenty-two (10.1%) samples fulfilled diagnostic criteria for SBP. Samples with SBP had a significantly higher lactoferrin concentration (median, 3744 ng/mL; 25th-75th percentiles [P25-P75], 788-9617) compared with non-SBP samples (median, 31 ng/mL; P25-P75, 12-67; P < .001). By using a cut-off level of 242 ng/mL, the sensitivity and specificity of the assay for diagnosis of SBP were 95.5% and 97%, respectively. The area under the receiver operating characteristic curve was 0.98. AFLAC can serve as a sensitive and specific test for diagnosis of SBP. Qualitative bedside assays for the measurement of AFLAC can be developed easily and may serve as a rapid and reliable screening tool for SBP in patients with cirrhosis.

Heart-type Fatty acid-binding protein in Acute Myocardial infarction Evaluation (FAME): background and design of a diagnostic study in primary care.

BackgroundCurrently used biomarkers for cardiac ischemia are elevated in blood plasma after a delay of several hours and therefore unable to detect acute coronary syndrome (ACS) in a very early stage. General practitioners (GPs), however, are often confronted with patients suspected of ACS within hours after onset of complaints. This ongoing study aims to evaluate the added diagnostic value beyond clinical assessment for a rapid bedside test for heart-type fatty-acid binding protein (H-FABP), a biomarker that is detectable as soon as one hour after onset of ischemia.MethodsParticipating GPs perform a blinded H-FABP rapid bedside test (Cardiodetect®) in patients with symptoms suggestive of ACS such as chest pain or discomfort at rest. All patients, whether referred to hospital or not, undergo electrocardiography (ECG) and venapunction for a plasma troponin test within 12–36 hours after onset of complaints. A final diagnosis will be established by an expert panel consisting of two cardiologists and one general practitioner (blinded to the H-FABP test result), using all available patient information, also including signs and symptoms. The added diagnostic value of the H-FABP test beyond history taking and physical examination will be determined with receiver operating characteristic curves derived from multivariate regression analysis.ConclusionReasons for presenting the design of our study include the prevention of publication bias and unacknowledged alterations in the study aim, design or data-analysis. To our knowledge this study is the first to assess the diagnostic value of H-FABP outside a hospital-setting. Several previous hospital-based studies showed the potential value of H-FABP in diagnosing ACS. Up to now however it is unclear whether these results are equally promising when the test is used in primary care. The first results are expected in the end of 2008.

Predicting outcome using butyrylcholinesterase activity in organophosphorus pesticide self-poisoning.

The usefulness of a low butyrylcholinesterase (BuChE) activity on admission for predicting severity in acute organophosphorus (OP) insecticide poisoning has long been debated. Previous studies have been confounded by the inclusion of multiple insecticides with differing inhibitory kinetics. We aimed to assess the usefulness of admission BuChE activity, together with plasma OP concentration, for predicting death with two specific organophosphorus insecticides. A prospective cohort of self-poisoned patients. We prospectively studied 91 and 208 patients with proven dimethoate or chlorpyrifos self-poisoning treated using a standard protocol. Plasma butyrylcholinesterase activity and OP concentration were measured on admission and clinical outcomes recorded. The usefulness of a plasma BuChE activity <600 mU/ml on admission varied markedly--while highly sensitive in chlorpyrifos poisoning (sensitivity 11/11 deaths; 100%, 95% CI 71.5-100), its specificity was only 17.7% (12.6-23.7). In contrast, while poorly sensitive for deaths in dimethoate poisoning [12/25 patients; 48%, (27.9-68.7)] it was reasonably specific [86.4% (75.7-93.6)]. A high OP concentration on admission was associated with worse outcome; however, a clear threshold concentration was only present for dimethoate poisoning. Plasma BuChE activity on admission can provide useful information; however, it must be interpreted carefully. It can only be used to predict death when the insecticide ingested is known and its sensitivity and specificity for that insecticide has been studied. Plasma concentration of some OP insecticides predicts outcome. The development of rapid bedside tests for OP detection may aid early assessment of severity.