Reflecting the importance of the subject and the interest in it, the number of peer-reviewed papers covering point-of-care testing is huge, to such an extent that it is frequently difficult for healthcare professionals to keep up with the literature. As a special service to our readers, IHE presents a selection of literature abstracts, chosen by our editorial board as being particularly worthy of attention.
Use of saliva-based nano-biochip tests for acute myocardial infarction at the point of care: a feasibility study.
Floriano PN et al.
Clin Chem 2009; 55(8): 1530-8.
This paper investigated the feasibility and utility of saliva as an alternative diagnostic fluid for identifying biomarkers of acute myocardial infarction (AMI). Luminex and lab-on-a-chip methods were used to assay 21 proteins in serum and unstimulated whole saliva obtained from 41 AMI patients within 48 hours of chest pain onset and from 43 apparently healthy controls. Data were analysed to evaluate the diagnostic utility of each biomarker, or combinations of biomarkers, for AMI screening.
Both established and novel cardiac biomarkers demonstrated significant differences in concentrations between patients with AMI and controls without AMI. The saliva-based biomarker panel of C-reactive protein, myoglobin and myeloperoxidase exhibited significant diagnostic capability and, in conjunction with ECG, enabled effective screening for AMI comparable to that of the panel (brain natriuretic peptide, troponin-I, creatine kinase-MB, myoglobin), far exceeding the screening capacity of ECG alone. These whole saliva tests were adapted to a novel lab-on-a-chip platform for proof-of-principle screens for AMI. The authors conclude that as a complement to ECG, saliva-based tests within lab-on-a-chip systems may provide a convenient and rapid screening method for cardiac events in prehospital stages for AMI patients.
Prediction and management of bleeding in cardiac surgery.
Despotis G et al.
J Thromb Haemost 2009; 7 Suppl 1: 111-7.
Excessive bleeding after cardiac surgery can result in increased morbidity and mortality related to transfusion- and hypoperfusion-related injuries to critical organ systems. The objective of this study was to review mechanisms that result in bleeding after cardiac surgery as well as current and emerging interventions to reduce bleeding and transfusion. The authors demonstrated that point-of-care tests of haemostatic function can facilitate the optimal management of excessive bleeding and reduce transfusion by facilitating administration of specific pharmacological or transfusion-based therapy and by allowing physicians to better differentiate between microvascular bleeding and surgical bleeding. The authors consider that while emerging interventions such as recombinant FVIIa have the potential to reduce bleeding and transfusion-related sequelae and may be life-saving, nevertheless randomised, controlled trials are needed to confirm safety before they can be used as either first-line therapies for bleeding or bleeding prophylaxis. Careful investigation of the role of new interventions is essential since the ability to reduce use of blood products, to decrease operative time and/or re-exploration rates has important implications for overall patient safety and healthcare costs.
Point-of-care assessment of antiplatelet agents in the perioperative period:
a review.
Gibbs NM.
Anaesth Intensive Care 2009; 37(3): 354-69.
The aim of this paper was to review the strengths and limitations of current ‘point-of-care’ techniques for the detection of antiplatelet drug effects. The review was based on a Medline search for articles with key words related to “platelet function tests”, “point-of-care”, and “anaesthesia”, published in English between January 1996 and September 2008.The authors found that global assessments of ‘haemostasis’ are not specific for platelet function and are essentially insensitive to cyclooxygenase inhibitors and P2Y12 antagonists. Global assessments of ‘platelet function’ are more specific for platelet function, but also have limited sensitivity for cyclooxygenase inhibitors and P2Y12 antagonists. The newer devices developed specifically for the assessment of antiplatelet drugs, such as Platelet Mapping, the Impact Cone and Platelet Analyser and the VerifyNow, are more promising, but are not as sensitive as laboratory platelet aggregometry. All three categories of devices detect G(p)II(b)/III(a) antagonist activity, but not all provide quantitative assessments for monitoring therapy. The limitations appeared to be related to the complexity of platelet function, the multiple pathways of platelet activation, the wide interpatient variability in platelet responses and the interdependence between platelets and other aspects of coagulation. The authors conclude that the strengths and limitations of point-of-care devices should be appreciated before they are used to assist clinical decision-making in the perioperative period.
The limitations of point-of-care testing for pandemic influenza: what clinicians and public health professionals need to know.
Hatchette TF et al.
Can J Public Health. 2009; 100(3): 204-7
Many governments have made significant funding commitments to influenza vaccine development and antiviral stockpiling. The authors consider that while these are essential components of a response to pandemics, rapid and accurate diagnostic testing remains an often neglected cornerstone of pandemic influenza preparedness. The benefits and drawbacks of different influenza tests in both seasonal and pandemic settings need to be understood. Culture has been the traditional gold standard for influenza diagnosis but requires from 1-10 days to generate a positive result, compared to nucleic acid detection methods such as real time reverse transcriptase polymerase chain reaction (RT-PCR). Although the currently available rapid antigen detection kits can generate results in less than 30 minutes, their sensitivity is suboptimal and they are not recommended for the detection of novel influenza viruses. The authors conclude that until point-of-care (POC) tests are improved, the best option for pandemic influenza preparation is the enhancement of nucleic acid-based testing capabilities.
Point-of-care testing in microbiology: the advantages and disadvantages of immunochromatographic test strips.
Stürenburg E, Junker R.
Dtsch Arztebl Int. 2009; 106(4): 48-54.
This study describes the current technical status of Point-of-Care Testing (POCT), giving some examples, and summarises the specific advantages and disadvantages of the POCT approach in microbiology. The conclusions are that the test systems available today are technically mature and offer good to very good performance. For HIV, malaria, group A streptococci, and legionellae, POCT, when indicated, is on a par with conventional procedures. The information yielded by rapid tests for pneumococci and for influenza tends to be supplementary in nature. The rapid test for group B streptococci is unsuitable for routine use because its sensitivity is still too low compared with bacterial culture. POCT can be successful only if the tests are performed correctly by trained personnel, quality management procedures are followed, and the severity of illness and the epidemiological circumstances are taken into account when interpreting the results.
