Psychosis
Dear Editor
I refer to the article by Lee and Jureidini, ‘Emerging psychosis in adolescents’ (AFP September 2013).
Early symptoms of adolescent psychotic illness can be very subtle and thus a missed diagnosis during the early stages of the illness is common. It is often not until the psychosis is very overt when the diagnosis is made and treatment started. At this late stage the condition is much more difficult to treat. It is also often during this late stage when patients become a danger to themselves and others. Lee and Jureidini mention that there should be a cautious and measured approach to diagnosis and treatment but, in reality, delayed diagnosis and management can be fraught with risk.
The example used in Lee and Jureidini’s case study, where the patient has one general practitioner consultation and an immediate admission via emergency, is often not as simple as that. Patients often have multiple presentations to health professionals and emergency departments before the correct diagnosis is made.
Also, Lee and Jureidini mention the use of alcohol and illicit drugs on a number of occasions throughout their article, including in the case study. While it is important to mention the possibility of alcohol and illicit drug use, it is important to remember that many adolescents who present with a psychotic illness have had no association with alcohol and illicit drugs.
Dr Chris Clohesy
Member of Executive, AMA National Council of General Practice
Adelaide, SA
Reply
Dear Editor
The authors thank Dr Clohesy for his thoughtful comments about our article, but point out that a ‘cautious and measured approach to diagnosis and treatment’ does not equate to ‘delayed diagnosis and management’.
Dr Hsu-en Lee and Dr Jon Jureidini
Adelaide, SA
Myocardial perfusion scans
Dear Editor
I would like to thank Dr Lee and colleagues (AFP August 2013)2 for a most helpful overview of myocardial perfusion scanning. For the assessment of pilots and air traffic controllers, it is the prognostic risk information that is the primary interest of a transport regulator. Pilots and controllers are understandably confused when told by an interventional cardiologist that their angiogram is ‘fine’, but face restrictions to their aviation medical certification because there is a persistently abnormal functional test. Lack of a treatable angiographic lesion is not the same as a low-risk cardiac event. However, a normal perfusion scan is usually associated with an acceptable level of cardiac risk and, for this reason, a perfusion scan (or exercise echocardiogram, subject to the caveats in the article) are the preferred investigations to stratify risk.
My one suggestion, however, relates to the advice provided to patients (page 565): there should be mention of radiation dose. Numerous studies have highlighted the lack of monitoring of medical radiation exposure. The recent paper by Brown and Jones3 highlights the Australian experience. It is an area where doctors can both inform and oversee their patients’ ongoing exposure. Practitioners and patients should be aware of the relatively high exposure of a perfusion scan. Protocols vary but technetium scans are usually associated with estimated effective doses of 7–12 mSv.4 It is important that the use of this test is both judicious and informed.
Michael Drane
Senior Aviation Medical Officer
Aviation Medicine
Civil Aviation Safety Authority, Canberra
References
- Lee JC, West MJ, Khafagi FA. Myocardial perfusion scans. Aust Fam Physician 2013;42:564–67.
- Brown N, Jones L. Knowledge of medical imaging radiation dose and risk among doctors. J Med Imaging Radiat Oncol 2013;57:8–14.
- Estimates of effective doses of standard MPI protocols. Available at www.uptodate.com/ contents/image?imageKey=CARD/70759 &topicKey=CARD%2F5325 &source=outline_link&search =radfiation+dose+myocardial+ perfusion+scan&utd Popup=true [Accessed 11 August 2013].