Yuen and Tung describe a case of tuberculous osteomyelitis of the foot [1] and the potential difficulties in making the diagnosis. The authors were fortunate enough to have typical histological biopsy findings which subsequently cultured Mycobacterium tuberculosis (TB), providing diagnostic confirmation and estimations of sensitivities. However, in many instances, the diagnosis of tuberculosis is difficult to verify. For instance, acid fast bacilli may not be identified on biopsy or may be non-tuberculous in origin. Additionally, subsequent culture confirmation can take several weeks or may fail completely, due to TB's fastidious nature.

Although the reliance on clinical suspicion is the basis for the diagnosis of many cases of TB, definitive confirmation is desirable in view of the long-term nature of therapy. It is also important to ensure that the organism is not resistant to the chemotherapeutic regime being employed, particularly with the increasing incidence of multi-drug resistant TB strains. A number of novel diagnostic techniques have been developed to facilitate this. The use of the polymerase chain reaction (PCR) to amplify specific TB DNA sequences allows a rapid confirmation of the diagnosis and an estimation of drug sensitivity [2]. These techniques have been successfully used on both clinical specimens and culture material [3]. Thus, acid fast bacilli can rapidly be identified as Mycobacterium tuberculosis and an estimation of rifampicin sensitivity can be obtained in a matter of days, free from the contraints of waiting up to several weeks for the standard culture to grow. These techniques should therefore be considered, particularly if the clinical findings are subtle or atypical.

References

(1) Yuen MC, Tung WK. An uncommon cause of foot ulcer: tuberculous osteomyelitis. Emerg Med J 2001; 18: 140-141.
(2) Telenti A, Imboden P, Marchesi F, et at. Detection of rifampicin-resistance mutations in Mycobacterium tuberculosis. Lancet 1993;341:647-650.
(3) Shah S, Miller A, Mastellone A, et al. Rapid diagnosis of tuberculosis in various biopsy and body fluid specimens by the AMPLICOR Mycobacterium tuberculosis polymerase chain reaction test. Chest 1998;113: 1190-1194.

While I agree that the specialty in the UK should move to using the title "Emergency Medicine" I would council that it may be difficult to gain acceptance of the name amongst the wider community - both medical and non- medical.

Here in Australia, the specialty has been officially named "Emergency Medicine" since the Australasian College for Emergency Medicine was incorporated in 1984. However, this message has not permeated the wider community. On a daily basis, I field letters and phone calls for "cas", "casualty", A&E, to name but three of the most common names used. The process of re-education begins as soon as the name change becomes official – but obviously the effective timescale is an extended one. Thus I would recommend that the name change be made as soon as possible – and let the schooling process begin!

Dear Editor

The effects of sexual assault can be devastating; we commend Fong for raising the profile of this topic within Accident and Emergency Medicine.[1] There are, however, a number of areas where we feel the guidance in that paper could be improved. The data about HIV prevalence and risk groups were out of date. We cite more recent data and guidance that may alter readers' approach to this situation.

Up to the end of June 2001, there had been 46131 reported cases of HIV infection in the United Kingdom.[2] The incidence of new HIV diagnoses has increased each year since 1994. Since 1999 heterosexual intercourse has been the commonest route of transmission.

Fong rightly emphasises that "HIV counselling and PEP is but one aspect of the care and treatment of the rape victim". Although HIV infection is especially worrying, sexual assault can lead to other sexually transmitted infections and to (unwanted) pregnancy. Staff able to diagnose and treat STIs and able to provide emergency contraception should care for these patients. The optimum timing of testing for STIs is 10-14 days after the rape.

All anti-retroviral drugs can have significant side effects and dangerous drug interactions. If it is felt that post-exposure prophylaxis (PEP) might be needed, a suitably experienced clinician must be involved: the most recent UK guidance states "after an exposure outside the health care setting considered to carry a high risk of HIV infection, expert advice should be sought urgently from a physician experienced in the management if HIV and familiar with the considerations for the use of PEP".[3] This guidance suggested that when starter packs were being replaced they contain zidovudine, lamivudine and the protease inhibitor nelfinavir (rather than indinavir, which is poorly tolerated because of dietary restrictions needed when taking it). The guidance does not recommend any two-drug regimen, nor does it mention a 72-hour window. It states that PEP may be indicated up to 2 weeks after exposure.

All patients in whom HIV testing or PEP are considered require adequate counselling. Physicians in Genito Urinary Medicine or HIV Medicine will have more extensive experience in these areas than most clinicians in Accident and Emergency Medicine; we feel the failure of the review to suggest immediate referral to GUM or another specialty familiar with HIV management is a major omission.

We strongly advise anyone working in the UK who is considering providing PEP to first read the Expert Advisory Group on AIDS recommendations.[3]

References
(1) Fong C. Post-exposure prophylaxis for HIV infection after sexual assault: when is it indicated? Emerg Med J 2001;18:242-245.
(2) CDR Weekly. AIDS and HIV infection in the United Kingdom: monthly report July 2001. http://www.phls.co.uk/publications/CDR%20Weekly/pages/hiv.htm Accessed 10 August 2001 (update due 30 August 2001).
(3) UK Chief Medical Officers' Expert Advisory Group on AIDS. HIV post-exposure prophylaxis. Department of Health, 2000.

Dr S G Ralph
Consultant Physician in Genito Urinary and HIV Medicine
York District Hospital

Dr R D Hardern
Consultant Physician (Acute Medicine)
The General Infirmary
Leeds

Dear Editor

I read with interest the letter publication by Knowles on routine use of thrombolysis during all non-traumatic cardiac arrests, whether caused by pulmonary embolism ( PE ) or by myocardial infarction (MI).[1] His comment was based in relation to a case report by MacCarthy P et al (Emerg Med J 2002; 19: 178 -79.)

BTS guidelines mention performing urgent echocardiography for massive PE with collapse or hypotension. Right ventricular dysfunction on echocardiography has been reliably established as a predictor of increased likelihood of death from PE.

Recent research interest, however, has been hovering around measuring cardiac troponin (cTnT) in acute PE to assist risk stratification.[2] PE patients with elevated cTnT levels should undergo echocardiography to detect right ventricular dysfunction. This may portend a lethal combination in the presence of an elevated cTnT level. These patients could then be assessed to determine whether thrombolysis or embolectomy is a clically appropriate strategy.

Several issues would need to be resolved before such policy is implemented. Firstly, like in acute coronary syndrome optimal role and timing of measurement of troponin level in patients with PE need to be determined. Secondly, it is not known yet, whether elevated cTnt level is actually prognostically more important than right ventricular dysfunction on echocardiogram or not. Thirdly, whether the biomarkers such as brain natriuretic peptides will become more useful, equivalent or complementary to cTnT level in acute PE or not.[3]

Thrombolysis has its own hazards and therefore can not routinely be recommended in a ‘cardiac arrest’ scenario.

References

(1) Knowles P. Transthoracic echocardiography during cardiac arrest due to massive pulmonary embolism. Emerg Med J 2003; 20: 395.

(2) Goldhaber SZ. Cardiac biomarkers in pulmonary embolism. Chest 2003; 123: 1782-84.

(3) Kucher N, Printzen G, Doernhoefer T, et al. Low pro-brain natriuretic peptide levels predict benign clinical outcome in acute pulmonary embolism. Circulation 2003; 107: 1576-78.