Minerva

Compared with conventional surgical techniques, computer assisted navigated total knee arthroplasty significantly reduces the risk of systemic emboli detected by transcranial Doppler ultrasonography (Journal of Bone and Joint Surgery [Br] 2006;88: 198-202). In the study's computer assisted group no patient had more than two detectable emboli, with a mean of 0.64 (SD 0.74). In the non-navigated group the number of emboli ranged from one to 43, and six patients had more than two detectable emboli, with a mean of 10.7 (SD 13.5).

The mnemonic SIGECAPS (standing for sleep disturbance, interest diminished, guilt, energy loss, concentration difficulties, appetite change, psychomotor retardation, suicidal ideation or acts) is used to diagnose depression in the United States. However, an improved version might be C GASP DIE, not least to get around the problem of the two S's (and trying to recall what they stand for). Here, D represents thoughts or acts of death (American Journal of Psychiatry 2006;163: 329-30).

Family history of stroke is a risk factor for ischaemic stroke, but other factors can confuse the picture. For instance, data analysis from two population based studies and a series of patients referred to hospital with recent transient ischaemic attacks (TIA) reveals that family history of stroke does not predict a risk of ischaemic stroke after TIA Stroke 2006;37: 544-6).

The rising incidence of leg fractures in Cornwall is being blamed on skimboarding, a new sport popular among surfers. It involves throwing a round wooden disc into the shallow water of a receding wave, taking a running jump on to it, and riding it along the beach or into the surf. The beginner's learning curve is steep, and high energy torsional falls predispose riders to breaking their legs, as opposed to the wrist injuries characteristic of skating, rollerblading, or skateboarding Emergency Medicine Journal 2006;23: 137).

Electronic communications and booking systems are generally seen as the way forward for health services. But the result of a Canadian randomised controlled trial, which assessed the impact of an electronic link between an emergency department and 23 general practices, casts doubt on this optimistic view. The electronic link resulted in no significant reduction in resource use at either end of the service; although requests for diagnostic tests were not duplicated, there was a significant rise in the number of duplicated requests for specialist consultations CMAJ 2006;174: 313-8).

Fat can be clinically useful in one otherwise lethal situation, according to an editorial in Anaesthesia (2006;61: 107-9). An intravenous bolus of lipid can reverse refractory cardiovascular collapse caused by an overdose of local anaesthetic. There's little chance that high grade evidence for this procedure will become available, but the authors want to encourage clinicians to test it out—hopefully saving lives by doing so—and publicly report their findings.

A three year follow-up of workers in health and social services reports a clear link between burnout (as measured by the Copenhagen burnout inventory) and self reported sickness absence from work. After adjustment for health related confounding factors, a reduction in burnout was predictive of fewer sick days, and unaddressed burnout predictive of more sickness absence. Burnout had a stronger influence on the length of absence than on the frequency of absence periods Occupational and Environmental Medicine 2006;63: 98-106).

Koebner's phenomenon is the development of isomorphic pathological lesions in the traumatised uninvolved skin of patients with cutaneous diseases such as psoriasis, lichen planus, and vitiligo. This 70 year old man with psoriasis was referred for ultraviolet B (UVB) phototherapy. Minimal erythemal dose (MED) testing, performed before phototherapy to optimise treatment doses, provoked abnormal erythematosus and oedematous responses at all doses, indicating photosensitivity. This photograph was taken two weeks later, clearly showing koebnerisation of psoriasis into the photo test sites. Without MED testing, the patient would have had a painful erythroderma after phototherapy, followed by koebnerisation of his psoriasis.

Sasi K Attili (skattili{at}hotmail.com clinical research fellow, R M Ross Hearn, senior house officer, James Ferguson, consultant, Sally Ibbotson, clinical senior lecturer, Department of photobiology and dermatology, Ninewells Hospital and Medical School, Dundee DD1 9SY

A complex analysis of weather related changes in 24 hour blood pressure profiles reveals that hot weather is associated with a reduction in daytime blood pressure and an increase in systolic pressure at night, particularly in elderly people. Another finding was a strong morning surge in blood pressure in elderly people in cold weather. What it all means in terms of end organ damage and acute cardiovascular events in hypertensive patients isn't clear Hypertension 2006;47: 155-61).

How do parents make their final decisions and choices about immunising their children? A website for patients and parents which offers balanced views about immunisations has been launched by DIPEx, an online resource for the general public (http://www.dipex.org/). Parents can watch videos, listen to audio clips, and read extracts of interviews with more than 40 parents with young children. Some have chosen to vaccinate their children, others have not.

Oesophageal and stomach cancers share an unexplained male predominance, suggesting that oestrogen might have a protective effect. A nested case-control study among women with both kinds of cancer and controls found that taking hormone replacement therapy was associated with a 50% reduced risk of gastric cancer—especially non-cardia cancers—but showed no association with oesophageal cancer British Journal of Cancer 2006;94: 136-41. However, Helicobacter pylori infection was not controlled for.

Rheumatology patients get a raw deal. Their conditions arise from dodgy immune systems, and the long term treatment they need causes further immunosuppression. But when it comes to being vaccinated, they seem to be missing out. Current vaccination rates sit at around 20%-35% at best. Antibody titres tend to decline more quickly in immunosuppressed patients, but data show that the pneumococcal and annual flu jabs do induce a reasonable immune response despite this Rheumatology 2006;45: 9-10).

Guidance at bmj.com/advice