ISLAMABAD (Online) Teenagers who smoke, or whose mother smoked in pregnancy, are at higher risk of hearing problems and understanding what is being said, a US study says. In tests on 67 teenagers, Yale University found those exposed to smoke had trouble focusing and interpreting sounds when there was a distraction. And the team said scans showed exposure changed the brains white matter, responsible for transmitting messages. The findings were reported in New Scientist magazine. The team carried out brain scans on the teenagers and found those exposed to smoke were more likely to have more white matter. Previous research has shown that children with overdeveloped white matter have problems transmitting and interpreting sound because the white matter it is out of sync with the rest of the brain. The researchers believe the over-production of the white matter is caused by nicotine stimulating a chemical compound called acetylcholine. Further evidence was also provided by the computer tests the teenagers, aged 13 to 18, completed where they were asked to recognise words while being distracted by visual images or background noise. Among the boys who were tested, those exposed to smoke got 77 per cent right, whereas those not exposed got 85 per cent right. In girls, the breakdown was 84 per cent to 90 per cent. The researchers said the results were quite significant. Lead researcher Leslie Jacobsen said: Individuals affected will have problems in settings where there is a distraction. This could certainly be the case in classrooms where there may be other people talking and lots of things going on. Coupled with other conditions, such as behavioural disorders, this may tip a pupil towards failing at school. David McAlpine, director of the Ear Institute at University College London, agreed the findings were interesting. He added: The fact that smokers show changes in this pathway means they may be less able to hear whats being said. Richard Todd, from Washington University, added the effect on the white matter was pretty remarkable. It seems the brain remains vulnerable long into adolescence. Medical abbreviations 'pose risk Doctors are being warned that using abbreviations in medical notes is putting patients lives at risk. The UKs Medical Defence Union said difficulties often arose because abbreviations can have more than one meaning or might be misread. Some patients have had the wrong limb removed or operated on and others have been given deadly drug doses, it said. A recent US study of 30,000 medication errors, some fatal, showed 5% were linked to abbreviations in notes. Common errors included abbreviating drug names and dosages, the Joint Commission found. An example involved a 62-year-old patient on haemodialysis who was treated for a viral infection with the drug acyclovir. The order for acyclovir was written as acyclovir (unknown dose) with HD, meaning haemodialysis. Acyclovir should be adjusted for renal impairment and given only once daily. However, the order was misread as TID (three times daily) and the patient died as a result. A UK audit by the paediatric department at Birmingham Heartlands Hospital, published in the Archives of Disease in Childhood in November, found instances where abbreviations used had caused confusion because they had multiple interpretations. For example, TOF could be taken to mean tetralogy of fallot or tracheo-oesophageal fistula - two completely different conditions. When presented with a selection of abbreviations, the study authors found paediatric doctors agreed on the interpretation of 56-94 per cent, while other healthcare professionals recognised only 31-63 per cent. The authors also found that the use of abbreviations was inconsistent - 15% of the abbreviations used in medical notes appeared in the hospitals intranet dictionary while 17 per cent appeared in a medical dictionary used by paediatric secretaries. The MDU, which defends members reputations when their clinical performance is called into question, advises doctors to use only the abbreviations or acronyms that are unambiguous and approved in their practice or hospital. Dr Sally Old, MDU medico-legal adviser, said: Abbreviations can cause confusion and risk patient safety. In one instance a diabetic patient was given a dose of 61 units of insulin because the notes say six international units - 6IU - were misinterpreted. Thankfully, the error was spotted and the patient was treated. She said clear, concise communication was essential, particularly when care was provided by multi-disciplinary teams. Kevin Cleary, of the National Patient Safety Agency, said: Abbreviations in clinical notes, prescriptions and treatment charts should be kept to an absolute minimum. They cause confusion and present a risk to patients. The NPSA is aware of at least one patient death in the last 12 months where abbreviations were a contributory factor. In response to this incident, involving chemotherapy, we will be issuing guidance later this month on clear communication of treatment protocols. Universal flu jab works in people A single jab that could give lifelong protection against all types of flu has produced promising results in human trials. The vaccine, made by Acambis, should protect against all strains of influenza A - the cause of pandemics. Currently, winter flu jabs have to be regularly redesigned because the flu virus keeps changing. The new vaccine would overcome this and could be stockpiled in advance of a bird flu outbreak, say experts. Each year winter flu kills around 4,000 people in the UK. Globally, between 500,000 and one million people die each year from influenza. But a pandemic of the human form of bird flu, which experts believe is inevitable, could kill as many as 50m people worldwide. The US trials show that the jab is safe and it works fast to make the body immune against flu. Nine out of 10 of those who had two doses of the jab ACAM-FLU-A developed antibodies against flu virus. Scientists at Acambis are now working to perfect the formulation before doing larger human trials. Dr Michael Watson of Acambis said: As a universal vaccine, ACAM-FLU-A can potentially overcome many of the drawbacks of existing influenza vaccines. It can be manufactured at any time of the year, and could be stockpiled in advance of a pandemic or potentially used routinely to ensure population protection against future pandemics. Current flu vaccines work by giving immunity to two proteins called haemagglutinin and neuraminidase, which are found on the surface of flu viruses. However, these proteins keep mutating which means doctors have to keep making new vaccines to keep up. The Acambis vaccine homes in on a different protein, called M2, which is found on the surface of all A-strains of flu and does not appear to mutate so readily. Professor Ian Jones, a University of Reading virologist, said the jab could end the scramble to produce a new winter jab each year. But he said it would still be some years before it was widely available for patients. Larger trials and tests on a wider range of viruses will be needed before the full potential for pandemic protection can be assured, he said.