 | What Your Doctor Is Reading | | |
Update From the Medical Journals: December 2007
January 2, 2008  By Mary Pickett, M.D.
Harvard Medical School What's the latest news in the medical journals this month? Find out what your doctor is reading. Antibiotics Don't Speed Recovery From Acute Sinusitis Antibiotic treatment doesn't make a measurable difference in how quickly a person recovers from acute sinusitis, say researchers from England. They published their findings from a randomized study in the December 5 issue of the Journal of the American Medical Association (JAMA). Researchers asked people from 58 clinics who had been newly diagnosed with a sinus infection to join their study. All of the patients had green or yellow discharge from their noses and many also had tender sinuses. The researchers randomly assigned patients to get treated with amoxicillin alone, amoxicillin and a nasal steroid spray, a nasal steroid spray alone, or no medicine. Everyone received a pill and a spray — people in the no-treatment group took placebo medicines — so no patient knew which group they were in. The treatment continued for a week. The patients who were treated with amoxicillin did not get better noticeably faster than people with no antibiotics: 29% of them had symptoms that lasted for ten days or more beyond when they started taking the medication compared with a basically idential number of people who were not on antibiotics. The steroid nose spray didn't make a difference overall, although recovery was somewhat faster for the patients who had the mildest symptoms. Antibiotics can cause allergies, side effects (stomach upset or diarrhea) and problems related to changes in your normal bacterial flora. For example, it is common for women to develop a yeast infection with vaginal itching after taking antibiotics. Also, the more often we use antibiotics, the faster resistant strains of bacteria appear. For these reasons, doctors need to avoid antibiotic prescriptions for problems that can get better on their own, unless antibiotics make an obvious difference. Doctors will be less willing to prescribe antibiotics for acute sinusitis after this study particularly for patients who have mild symptoms. For patients who have more serious symptoms, such as headache and fever, antibiotics might play a more important role. Back to top Study Confirms Long-Term Benefits of Breast Cancer Drug, Anastrozole On December 15, the Lancet published a study online that is welcome news for breast cancer patients and cancer specialists. It confirms that a newer medication called anastrozole (Arimidex), is more effective than tamoxifen for preventing the recurrence of hormone-receptor positive breast cancer over eight years. Cancer specialists have been using anastrozole as the treatment-of-choice for several years now for women with hormone-receptor positive breast cancer. Tamoxifen lost favor because anastrozole was shown to be at least as good as tamoxifen for preventing breast cancer recurrence, while having fewer side effects. But anastrozole's effectiveness had only been evaluated in short-term studies. With this new study, we now have data to compare it to tamoxifen over eight years. (Treatment took place during the first five years and then discontinued for the remaining three.) More than 6,200 women with early-stage breast cancer were enrolled in the study. Compared with five years of tamoxifen, five years of anastrozole treatment spared an additional 15% of women from recurrence of their cancer, according to a review of health records eight years after cancer diagnosis. Anastrozole slowed the recurrence rate of the cancer and prevented new cancer from forming in the opposite breast by more than 50%. Anastrozole is one of the more important advances in breast cancer treatment that took place this decade. It belongs to a class of hormonal medicines known as "aromatase inhibitors." Some breast cancers can be stimulated to grow by exposure to natural hormones. These cancers are called "hormone receptor positive" varieties. Artificial hormones have been developed that have an opposite effect on these same breast cancers and discourage the cancers from growing. Until several years ago, tamoxifen (Nolvadex). was the most successful hormonal medication we had for suppressing breast cancer. Some women, however, have serious side effects with tamoxifen. Also, about 30% of women using tamoxifen have a recurrence of breast cancer during the 15 years that follow their initial diagnosis. Back to top Chest Compressions Alone Can Improve Survival After Cardiac Arrest Two studies were published online on December 10 that are likely to change recommendations for CPR (cardiopulmonary resuscitation). Both studies — published in Circulation, the Journal of the American Heart Association — show that chest compressions can improve the odds of survival after a cardiac arrest (heart attack) outside of the hospital, whether or not rescue breathing (mouth-to-mouth resuscitation) is also provided. The first study compared the survival rates and brain function (among survivors) of more than 1,300 patients in Japan who received bystander CPR for cardiac arrests. People who were only given chest compressions were as likely to survive and as likely to have preserved brain (neurological) function one year later as people who received chest compressions and mouth-to-mouth resuscitation (rescue breathing). This was true unless the arrest lasted for longer than 15 minutes, in which case it was impossible for victims to survive without rescue breaths. The second study took place in Sweden and found that the one-month survival rate among 2,000 people who required CPR was almost identical for those who received chest compressions, with or without rescue breathing. The most critical time for chest compressions is the first few minutes after a cardiac arrest has occured. That's when there is plenty of oxygen in the blood, but the blood is not moving. That's because the heart isn't able to pump normally. Chest compressions by a bystander can be lifesaving because rapid and forceful pushes on the chest can squeeze the blood forward out of the heart. This keeps oxygen flowing to the brain, and it can also refresh the blood that is flowing into the coronary arteries on the surface of the heart. If the heart is receiving oxygen because a bystander is doing chest compressions, it is much more likely that the heart can restart its previously normal rhythm. In situations involving choking or drowning, rescue breaths are necessary as a part of CPR. Suffocation causes the blood oxygen to drop low first, and the heart stops as a side effect of too little oxygen. There is no oxygen "reserve" remaining in the blood. Rescue breaths are needed for a successful rescue. Nonetheless, for adults who have a sudden cardiac arrest, it may be useful to simplify CPR recommendations so that rescue providers are are able to give their full attention to giving fast and forceful chest compressions. If you hesitate to provide help to a victim who has arrested because you are uncomfortable giving mouth-to-mouth contact, remember that chest compressions alone may be life-saving. Back to top More News in Brief - Staying Physically Active Lowers Your Risk for Dementia. In Italy, researchers studied 749 adults over age 65 to see whether exercise and activity could reduce the risk for dementia. The study was published online December 19 by Neurology, the medical journal of the American Academy of Neurology. The most common types of dementia are Alzheimer’s dementia and vascular dementia (also called multi-infarct dementia). Vascular dementia occurs over time from repeated damage from several very small strokes. It is common in people who have artery damage related to high blood pressure. In the study, researchers divided the people into four groups based on how much physical activity they got in a usual week. They counted walking, stair climbing, gardening, housework, yard work or light carpentry, and more structured exercise. During the four years of the study, there were 81 adults who developed memory difficulties and received a new diagnosis of either Alzheimer's or vascular dementia. (About one-third of these adults with new dementia had vascular dementia.) Although there wasn't any clear relationship between exercise and Alzheimer's disease, there was an obvious relationship between exercise and risk for vascular dementia: The group with the highest total physical activity had a 24% lower risk for developing vascular dementia during the four years of the study.
- Radiation from CT Scans Poses Cancer Risk. A review article in the November 29 issue of the New England Journal of Medicine discussed the harmful side effects that are possible from radiation exposure during a CT (computed tomography) scan. Since 1980, the average American's radiation exposure has nearly doubled, because of the widespread use of CT scans in medical tests and treatments. They account for more than half of our radiation exposure. Experts estimate that the dose of radiation that comes from a CT scan is approximately 10 to 15 millisieverts, which is 100 times the amount from an X-ray. CT scans are used so commonly now in medical evaluation that their radiation contributes measurably to cancer risk. The authors of this paper estimate that as many as 1.5% to 2% of all new cancers in the United States might be triggered by radiation exposure from CT scans. Doctors and patients alike appear to underestimate the risks of radiation exposure from a CT scan, according to a survey. This article is a reminder that a CT scan should not be used without carefully weighing its risks and benefits.
Back to top Mary Pickett, M.D. is a lecturer for Harvard Medical School and an assistant professor of medicine at Oregon Health & Science University. At OHSU, she is a director of student programs and she oversees teaching of students and medical residents. She practices general internal medicine in Portland, Ore.
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