eLetters

255 e-Letters

  • The tension between "gestalt" and the checklist

    The tension between head, heart and checklist is strikingly exemplified by the clinical decision process involved in the diagnosis of pulmonary embolism(PE). Currently, this process is characterised by a proliferation of clinical decision rules which involve mind numbingly long lists of items, and their associated calculations, the latter intended to generate numerical scores(1)(2) which confer a semblance of scientific credibility to the process. By contrast, a school of thought has emerged which posits that clinical acumen, defined as unstructured clinical impression or "gestalt" is, at the very least, as reliable a sole reliance on clinical prediction rules for discriminating among patients who have a low, moderate, or high pretest probability of PE(1). Over time, gestalt, itself, appears progressively to confer increasing diagnostic accuracy, judging by the diagnostic performance of senior physicians(postgraduate year 4 plus) vs interns(postgraduate year 1) working in the emergency department of a large teaching hospital(3). Concurrently, we have seen the emergence of gestalt-based clinical decision strategies such as the PERC rule(4) and the YEARS algorithm(5). as an attempt to resolve the tension between underdiagnosis and overdiagnosis of PE.
    Clinical acumen, itself, performs best when it is informed, not only by the numerical score of years since obtaining one's medical qualification, but also by interaction(through the medium of case co...

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  • S1Q3T3R3 left arm – V2 ECG lead misplacement

    Dear Editor,
    We read with interest Thomson et al’s article “ECG in suspected pulmonary embolism” which was published in Postgraduate Medical Journal in January 2019. We would like to bring to your attention another important but little-known cause of S1Q3T3, namely left arm – V2 ECG lead misplacement. This occurs when the yellow ECG cables are misplaced and can easily be misdiagnosed as a pulmonary embolism. A characteristic appearance occurs which we believe is pathognomonic for LA – V2 misplacement. In addition to S1Q3T3, a tall R wave in lead III is seen (1). In a study of 62 patients in whom we recorded both a normal and an LA V2 ECG lead misplacement, we observed that the presence of S1Q3T3R3 is highly statistically significant for left arm -V2 lead misplacement (P=0) (1). It is important to exclude lead misplacement, or the patient may have incorrect treatment administered or the correct treatment withheld because of an error in recording an ECG. Of 230 unrecognised ECG lead misplacements in our hospital, 10.9% were left arm – V2 (2).
    After a thorough search of the literature we have identified only 2 brief reports on this topic (3,4). Therefore, it is highly likely that if it does occur then ECG features will inadvertently be attributed to pulmonary embolism and managed inappropriately.

    1. Lynch R, Ballesty L, Kuan SC, Ponnambolam Y. Left arm – V2 ECG Lead Misplacement by Colour: a largely unknown entity which can easily be Misdiagnosed as a Pulmo...

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  • Overuse of imaging might be attributable to suboptimal clinical decision rules

    The judgment that imaging studies were over-utilised (1) should not be based on the degree of compliance with the Wells clinical decision rule (CDR), given the fact that the Wells score is not necessarily the optimal one for PE. In a study which compared 7 CDRs, namely, the Wells score, simplified Wells score, original Geneva score, revised Geneva score, Charlotte score and the Pisa model, diagnostic accuracy amounted to 0.44, 0.61, and 0.76 for simplified Wells score, Wells score, and Pisa model, respectively (2). The Wells score was tested in 598 primary care patients presenting with symptoms including cough, unexpected or sudden dyspnoea, deterioration in existing dyspnoea, and pleuritic pain, singly or in combination. These patients were referred to secondary care with suspected PE, where they were subsequently rigorously evaluated and investigated according to hospital guidelines. The diagnosis of PE was subsequently confirmed in 73 cases. However, in as many as 44 of those cases where PE was ruled out, the presenting Wells score amounted to >4 points (3), a score that is taken to signify "PE likely" in the simplified Wells score. In the evaluation of PE diagnostic confusion is compounded by the fact that PE can be an incidental finding, for example, during CT imaging in the oncological context (4). In the latter study, 25% of 52 patients with incidental PE had no PE-related symptoms (4). In the entire group of 52 patients with incidental PE, eight had m...

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  • Terminology can be life-threatening

    The terminology of the chest x-ray report can, indeed, impact on the timeliness of the eventual validation of the diagnosis of pulmonary tuberculosis, as shown by the case report of a 75 year old man who was originally admitted with fever and backache. Chest x-ray showed "fibronodular infiltration of the left apex of the lung" (1). On the basis of magnetic resonance imaging, backache was attributed to osteomyelitis, and he was treated with antibiotics, and there was no "work-up" of the fibronodular infiltration of the lung apex. Over a period of two weeks fever persisted, and he became pancytopenic. However, it was only after a further 3 weeks, when pancytopenia became more severe, that bone marrow aspiration and bone marrow biopsy was performed. The latter showed epitheloid granulomas and acid fast bacilli. Polymerase chain reaction analysis of the bone marrow specimens was positive for M tuberculosis DNA, and his sputum was culture positive for M tuberculosis. Although antituberculous chemotherapy was initiated immediately after the bone marrow results he died 3 days after commencing treatment (2).
    Comment
    Arguably, if the term "tuberculosis" had been used to qualify the nodular infiltration seen on chest x-ray, that would have raised the index of suspicion for tuberculosis (TB), and computed tomography might have been utilised to characterise the nodularity as being TB-related (2). Two weeks later, in the light of that heightene...

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  • role of new oral anticoagulants in mitigating the risk of heparin-induced thrombocytopenia in cancer patients

    Given the fact that the risk of heparin-induced thrombocytopenia (HIT) is higher with prolonged therapy, the new oral anticoagulants (NOACs) might have a role in shortening the duration of low molecular weight heparin (LMWH) thromboprophylaxis in cancer patients from its currently recommended minimum of 3 months (1) to a much shorter duration by facilitating a transition to NOACSs( 2). That strategy might mitigate the risk of occurrence of HIT.
    Currently, international guidelines recommend LMWH instead of warfarin for management of cancer-related venous thromboembolism (1), but the duration of that management strategy puts patients at risk of HIT, with all its attendant consequences. In an open-label, noninferiority trial, patients with cancer-associated venous thromboembolism were randomly assigned to LMWH for at least 5 days followed by oral edoxaban (60 mg/day) (edoxaban group) or subcutaneous dalteparin at an appropriate dose. Treatment duration in both cases was at least 6 months. In that study, recurrent venous thromboembolism occurred in 7.9% of the edoxaban group vs. 11.3% of the dalteparin group (P=0.09). Major bleeding occurred in 6.9% of the edoxaban group vs. 4% of the dalteparin group (P=0.04). The increase in major bleeding was principally attributable to upper gastrointestinal bleeding in patients who had gastric cancer (2). A criticism of that study is that the 60 mg/day of edoxaban is inherently associated with significantly (P=0.03) greater risk of...

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  • The emerging role of new oral anticoagulants in HIT

    In their excellent review the authors drew attention to alternative oral anticoagulants to manage heparin-induced thrombocytopenia(HIT)(1). The American College of Chest Physicians guideline for HIT and HIT-associated thrombosis(HITT) cautions against premature transition to vitamin K antagonist therapy due to significant risk of warfarin-induced skin necrosis or development of venous limb gangrene(2). According to a recent review, the new oral anticoagulants(NOACs) are not burdened with that disadvantage, and their rapid onset of action generates a smooth transition to forward anticoagulation in patients with HIT/HITT. Furthermore, NOACs do not cross-react with HIT antibodies(3). That review encompassed data from 56 HIT/HITT patients subsequently treated with NOACs. Data were derived from 3 studies and 8 case reports. Mean age of the 56 patients was 70, twenty four had HIT, and thirty two had HITT. At the time of HIT/HITT diagnosis a nonheparin parenteral agent was initiated in 42, and the remaining 14 transitioned to NOACs straightaway. The NOACS used in the 56 patients were rivaroxaban, apixaban, and dabigatran in 54%, 29%, and 18% of cases, respectively. There were only 2 instances of recurrent thrombosis with NOAC therapy. Major bleeding occurred in 3 patients who did not appear to be on NOAC therapy at the time of the bleed.
    References
    (1) Prince M., Wenham T
    Heparin-induced thrombocytopemia
    Postgrad Med J 2018;94:453-547
    (2)Linkins L-A....

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  • A point of view: Diuretics and many dietary components significantly increase the risk of uric acid stone formation--Our major concern

    A point of view:
    Diuretics and many dietary components significantly increase the risk of uric acid stone formation--Our major concern.
    We read with interest and applauded the authors of the review article that mentions adjustment of potential pathophysiologic defects by pharmacotherapy and strongly recommends dietary modification for the prevention of uric stone recurrence (1).
    Two thirds of urate excretion occurs at the kidney, the remainder being excreted by the gut. Earlier studies have suggested that the urate is almost fully reabsorbed and that the urate excreted by the kidney is the result of tubular secretion. But more recent data suggests that secretion plays little part, and that excreted urate largely represents the filtered urate which escapes reabsorption. (2)
    Different diuretics are likely to have different effects on the renal handling of urate, but this has not been critically ascertained; patients receiving more powerful loop diuretics have a higher risk of developing gout than those receiving the weaker thiazides (3)
    Conceptually, a visit to a beer garden is dangerous for two reasons, the intake of purine rich food and drinks (beer) and the intake of fructose-rich soft drinks that blocks certain urate transporters that facilitate urate excretion (4).
    These are also associated with a number of common situations, such as the metabolic syndrome, which is correctable by changing to a low caloric diet, essential hypertensio...

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  • Secondary syphilis in the context of HIV-related immunosuppression

    The secondary syphilis we see today is potentially different from the secondary syphilis which belongs to the era antedating the presently high incidence and prevalence of human immunodeficiency virus (HIV) infection. Sexually active subjects who harbour the coexistence of HIV infection (with attendant immune suppression) and syphilis are also at risk of opportunistic infections such as tuberculosis and cryptococcosis (1)(2)(3). In one HIV-positive patient aged 43, neurosyphilis coexisted with both cryptococcal meningitis and tuberculous meningitis. The cerebrospinal fluid (CSF) was characterised by lymphocyte predominance low glucose and high protein. Furthermore, in the CSF, cryptococcal antigen amounted to 1;640, and the VDRL from the CSF was also reactive. CSF culture grew M. tuberculosis, and this was confirmed by the polymerase chain reaction (1). In another instance, a 37 year old man with past medical history of HIV infection had neurosyphilis coexisting with cryptococcal meningitis. The CSF was characterised by lymphocyte predominance, positive fluorescent treponemal antibody test and cryptococcal antigen titre of 1:640 (2). Another report involved a 40 year old man with coexisting neurosyphilis and cryptococcal meningitis. The CSF showed lymphocyte predominance and high protein concentration. Cryptococcus was cultured from the CSF and both serum serology and CSF were positive for syphilis (3). These anecdotal reports might underestimate the true prevalence of coe...

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  • Exercise training does reverse left ventricular diastolic dysfunction in high risk subjects

    While it is true, as the authors assert, that there is limited data on exercise-induced reversal of cardiac remodeling, a recent study suggests that the cardiac effects of sedentary aging(in middle age) can be reversed by exercise training(1). In that study sixty one(48% male) healthy sedentary participants of mean age 53 were randomly assigned to either 2 years of exercise training(n=34) or attention control(control=27). In each subject measurements were taken to evaluate left ventricular stiffness. Maximal oxygen uptake was measured to quantify changes in fitness. Fifty three participants completed the study. Adherence to prescribed exercise sessions was 88% on average. As a result of exercise training left ventricular stiffness was significantly(p=0.0018)reduced(right/ downward shift in the end-diastolic pressure-volume relationships) in comparison with its pre-exercise value. This parameter did not change in the control group. Exercise significantly(p<0.001)increased the left ventricular end diastolic volume , whereas pulmonary capillary wedge pressure was unchanged, thereby generating significantly(p=0.007) greater stroke volume for any given filling pressure. The authors concluded that regular exercise training could provide protection against the future risk of heart failure with preserved ejection fraction by mitigating the risk of increase in cardiac stiffness attributable to a sedentary lifestyle(1). Accordingly, although we cannot influence the natu...

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  • Choice of words is crucial in effective communication

    Improving communication in decision-making is a worthy goal and the choice of words is crucial. Sayma and colleagues (1) have not considered the implications of some of their choices.

    Firstly, throughout the article they have used the word ‘advanced’ when describing decisions and care plans. This is a common misspelling but such issues are not superior formats but are care plans and decisions made in advance. Secondly, the authors mention ‘ceilings of care’ but do not explain that there are no ethical or legal permissions that allow care to be limited. This term is often misused when what is meant is a limit to treatment options. Finally the use of ‘escalation’ in care plans has been shown to be threatening to patients.(2) The term is too often used by clinicians without considering how this might be considered by patients.

    None of this should not detract from the value of the information provided during the study, but perhaps the authors will think carefully in future about their choice of words.

    Claud Regnard

    References
    1. Sayma M et al. Improving the use of treatment escalation plans: a quality improvement study. Postgrad Med J, 2018; doi: 10.1136/postgradmedj-2018-135699.
    2. Fritz Z, Fudd JP. Development of the Universal Form of Treatment Options (UFTO) as an alternative to Do Not Attempt Cardiopulmonary Resuscitation (DNACPR) orders: a cross disciplinary approach. J Evaluation in Clinical Practice 2014; 21: 109-117.

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