Oxygen and Headaches

Severe Headache May be Treated With Oxygen

Headaches seem to be a common human condition, with almost everyone having suffered one at some point in life. In the spectrum of headaches, the most severe form is known as 'cluster' headaches. Clusters are characterized by excruciating pain behind or around one eye, tearing, drooping of the eyelid, runny nose and other symptoms. More men than women get them, with women who do describing the pain as "worse than childbirth." No surprise, then, that cluster headaches are one cause of suicide.

Yikes. Now there's good news with a study in this week's Journal of the American Medical Association: High-Flow Oxygen for Treatment of Cluster Headache. In 109 patients with cluster headaches, use of 100% oxygen delivered by face mask relieved the pain in almost 80%. In a very revelatory study design, participants who received oxygen also tried just room air delivered through a face mask, and only 20% responded. Clearly then, oxygen is important, and this makes sense in light of what we do know about headaches: blood vessels seem to constrict and relax and blood flow is compromised when a headache occurs. Since blood is delivering oxygen, perhaps that's the key.

Other really great aspects to this study include the fact that oxygen is non-toxic in this setting and doesn't have side effects, unless as Rick quips in the podcast, you are a smoker and you try to use your oxygen while you're smoking. Oxygen can be self-administered, in contrast to sumatriptan, one drug known to be effective but which must be injected. All around, a win-win for those who are unfortunate enough to have cluster headaches.

Now that this study has shown oxygen's benefit in cluster headache, the way is paved to try it in much more common migraine headaches as well. Here we also known that some blood vessel component is important so it may help. Stay tuned for studies addressing the use of oxygen in this much larger population of those who get bad headaches.

Other topics in this week's podcast include soy consumption and breast cancer survival, also in this week's JAMA, a new type of anticlotting medication in this week's NEJM, and in this issue of Archives of Pediatric and Adolescent Medicine, more evidence to support placing infants to sleep on their backs to avoid SIDS. Until next week, y'all live well.

Hope for an HIV Vaccine?

HIV Vaccine Provides Modest Benefit

The quest for an effective vaccine against HIV resembles a search for the Holy Grail. That's what I quip on this week's podcast, and while the phrase is tired and shopworn, in this case it fits. We've known about the cause of AIDS for decades now, the virus continues to kill tens of thousands annually, and although we have very effective drugs that keep the virus in check they are too expensive to offer much solace to much of the world's HIV infected population. In this week's NEJM, a glimmer of hope is reported: Vaccination With ALVAC and AIDVAC to Prevent HIV-1 Infection in Thailand.

Thailand is a country with a large population of both HIV infected people and those at risk for contracting the virus. Investigators evaluated over 16,000 volunteers who received multiple injections of the vaccine. Each volunteer was monitored for whether they became infected with HIV at the end of the six month vaccination series, and again at six month intervals for three years.

A couple of things are worth mentioning about the study subjects: they were not infected with HIV at the beginning of the study but were at risk for infection, either because they were sexual partners with someone who was already infected, they used IV drugs, shared needles, frequented commercial sex workers and the like. Subjects were categorized for whether they were at low, moderate or high risk for contracting the infection, and they were largely heterosexual.

At the end of the study, the vaccine was about 30% effective in preventing infection with HIV, depending on how the analysis was done. While this is not a great result, it's the best we have so far and the study tells us some very important things. First of all, traditional measures of vaccine efficacy don't apply in this case. Vaccination didn't impact on how many viruses were found circulating in the blood of those who subsequently became infected, nor did it have any effect on CD4 cells, the critical immune cell depleted by HIV. We also learned that multiple vaccinations were required. But it is a positive step and that's worth celebrating.

It's also important to mention that this study didn't go forward the way most do in that volunteers were not recruited, given the vaccine and then deliberately exposed to HIV, the way we assess many other vaccines. Clearly such a protocol would be unethical.

Other podcast topics this week include use of left ventricular assist devices in folks with heart failure, also in NEJM, aspirin use in those with stomach ulcers and consideration of a new bug in sore throats in young adults in Annals of Internal Medicine. Until next week, y'all live well.

Medications on the Fly

Should IV Drugs be Given During Out-of-Hospital Cardiac Arrest?

For many years folks who study survival related to heart attacks experienced out of the hospital have lobbied for allowing emergency medical technicians (EMTs) to administer a range of drugs as well as other interventions. The clear goal is to improve a person's chances of making it to the hospital alive, where hopefully treatment will result in long term survival. Now a study done in Norway seems to conclude that use of the most common medication, epinephrine, does not result in any benefit to these folks and may actually result in harm. That's in this week's Journal of the American Medical Association: Intravenous Drug Administration During Out-of-Hospital Cardiac Arrest.

This study could only have been done in a country other than the US (that would be Norway), since about half of the study subjects (a total of 851) were given advanced cardiac life support only and the other half given life support plus intravenous drug administration. As Rick says, in this country IV drug administration is dogma, and a failure to use it heresy, in spite of the fact that no direct evidence of the benefits of epinephrine use in this context exists.

The study found that while slightly more people made it to the hospital alive when IV medication was used there was no statistically significant difference between the two groups related to hospital discharge, quality of CPR, or long term survival. The authors conclude, and Rick agrees, that larger studies examining this issue need to be conducted and perhaps some modification of resuscitation guidelines is in order.

Two things emerge from this study that are worth noting: one is the wholesale adoption and institution of a practice, that is, establishment of an IV line and use of epinephrine in those who've suffered cardiac arrest outside the hospital, in the total absence of any data examining this specific issue but rather extrapolations from animal models and other circumstances where a benefit was perceived. At best, rather contrary to our current climate of 'evidence based' medicine.

The other is the ongoing debate about best practices related to resuscitation efforts. Should CPR be done on the chest or the back? Are ventilations (breaths) even necessary? What is the optimal timing for chest compressions? How long should the practice be continued until emergency personnel arrive? What about use of automated external defibrillators?

Perhaps the most compelling reason the debate is so fierce is that heart disease remains the 8000 pound gorilla when it comes to causes of death, killing almost half a million people in 2005, according to American Heart Association statistics. That's a lot of people. By and large, many if not most of these deaths could be avoided if people would never start smoking or quit if they do so currently, watch their weight and diet, and exercise regularly. High blood pressure should be controlled, and those with a family history of cardiac problems perhaps elect other interventions as well. Until then, relying on changes in treatment or management guidelines is a BandAid approach.

Other topics this week include the change in cervical cancer screening guidelines issued by the American College of Obstetricians and Gynecologists, pain and falls in the elderly and no volume benefit seen with angioplasty in this week's JAMA. Until next week, y'all live well.

Breast Cancer Screening Guidelines

Reduced Need for Mammography

Unless you've been living under a slimy rock this week, you know that the US Preventive Services Task Force has changed the screening guidelines for breast cancer. Instead of annual mammograms for all women over the age of 40, the guidelines are now tailored to reflect when the risk for developing breast cancer increases, and that's largely after menopause. Incidentally, right when the risk for the real killer in the room, heart disease, also rises. Here's the link to the recommendations, published in Annals of Internal Medicine: Screening for Breast Cancer: US Preventive Services Task Force Recommendation Statement.

The buzz over this change has been astonishing. The most pejorative comments seem to be coming from women concerned about a reduction in services at a moment when the nation is closely examining the spectrum of healthcare costs and seeking ways to reduce them. The outcry is fraught with allegations that women are once again being relegated to second class citizenry, with improvement in the nation's healthcare budget coming at the price of breast health. Really. Here's a novel idea: let's examine the data.

The data analysis shows that the number of screening mammograms needed to extend one woman's life relative to breast cancer in those aged 40 to 49 is 1904. That's a lot of screening, and as we're now seeing that radiation itself related to mammography may be harmful since its effects are cumulative, that's also a lot of potential damage. Add to that the psychological impact of being told you have a lump in your breast, the need for biopsy and perhaps lumpectomy, and the risk/benefit ratio tips clearly in the direction of reduced screening.

What about breast self-examination? The task force also found that there's insufficient evidence to support continued endorsement of this practice. But clearly, women are free to examine their breasts and report suspicious findings to their healthcare provider. No harm there.

Finally, the furor has been so overwhelming that for now, federal agencies that pay for routine annual mammography have stated that they will continue to do so. Since private insurers largely follow their lead, women who feel strongly about continued annual mammography are free to do so.

Interestingly, another issue critical to women's health we didn't talk about this week in the podcast is the change in recommendations for cervical cancer screening. Once again, data driven and based on research related to risks and benefits. And just to give fair play to the guys, the PSA/prostate cancer controversy also rages on, with Rick having stated that he hasn't had PSA screening and doesn't intend to anytime in the near future.

Other topics this week include whether more of a statin or the supplement niacin is best to reduce cholesterol from the American Heart Association meeting, published online in NEJM, dangers of drugs to stimulate red blood cell production in NEJM, and the relationship between cancer and vitamin B12 and folate supplements in JAMA. Until next week, y'all live well.

Statins and Gallstones

Will Statins Soon be Added to Municipal Water Supplies?

Yet another benefit has been added to the list related to the use of statins - those medications intended primarily to reduce cholesterol in the blood. Why reduce cholesterol? Because high cholesterol is associated with a host of nasty consequences: narrowing or blockage of blood vessels and subsequent clot formation, heart attacks or strokes among them. Now what else is good about statin use? Turns out long term use of statins results in fewer folks forming gallstones and requiring surgical removal of their gall bladder. That's in the current issue of JAMA: Statin Use and Risk of Gallstone Disease Followed by Cholecystectomy.

Researchers in England, where they are famous for collecting health data on people as part of their national health service and doing studies on it, looked at over 27,000 people who had had their gallbladder removed (a cholecystectomy in medical jargon) and compared them on a number of variables to over 106,000 people who had not. Thousands in both groups had been taking statins.

The conclusion was that people who had taken statins for a couple of years had a reduced risk of forming gallstones that eventually required gallbladder removal. This is good news all around since cholecystectomy, while most often done laparoscopically where only small incisions are required, is still surgery with its consequent risks. From a public health perspective avoiding this operation results in huge savings to our health care system.

The study also accounted for other factors related to the formation of gallstones: female gender, obesity, high-carbohydrate and high-fat diet, and use of estrogen-containing contraceptives among them. Even when these factors were taken into account the benefit of statins remained. And as Rick quipped at the beginning of the podcast, it sure seems like statins have such a multitude of benefits we may one day supplement water supplies with them, much as we do with fluoride to prevent cavities in teeth.

But there are caveats to statin use: some people complain of muscle aches and pains, and a very small percentage will experience a compromise of liver function and need to stop taking them. So for now, taking statins if you have high cholesterol in your blood or if you are about to undergo certain types of surgery may help, but avoiding gallstones should not be your primary objective.

Other topics in this week's podcast include having your blood tested for lipids may not require fasting (!) in this week's JAMA, mood improvement on a low fat diet in Archives of Internal Medicine, and treatment of blockages in the arteries to the kidneys in NEJM. Until next week, y'all live well.

Which Bypass Surgery is Best

The Final Word on Bypass Surgery?

Coronary artery bypass surgery, abbreviated CABG and pronounced like the vegetable, is necessary when someone's coronary arteries, those that supply the heart muscle itself with blood, become so extensively blocked that they must be replaced. The traditional way to do this is to crack open the patient's chest, harvest blood vessels from elsewhere in the body (yet another controversy we'll leave alone for today) and stitch them into place on the heart, thereby bypassing the blocked vessels.

Also traditional in this operation is stopping the person's heart. A dandy machine we'll call a heart lung bypass machine circulates the blood and provides oxygen to it while the heart is stopped. Once the new vessels are in place the heart is restarted, and voila! It now has enough blood to do its work. So what is the problem?

Lots of folks have complained that following this big operation, they had trouble thinking and remembering. The speculation was that stopping the heart was the cause, so a new operation was developed where the heart was left beating. A nimble surgeon stitched the new vessels into place on this moving target. But alas, problems existed with this operation as well, and now a big study in the New England Journal of Medicine has compared the two: On Pump Versus Off Pump Coronary Artery Bypass Surgery.

Over 2200 people were randomized, which means assigned to one group or the other essentially by a flip of a coin, to either on pump or off pump surgery. They were assessed at 30 days and again at a year, and the take home message is this: those who underwent the traditional surgery where their heart was stopped did better. There was no discernible difference between the two groups in thinking, or cognition, but those who had on pump surgery had a better blood supply to their heart and other superior outcomes.

Rick gives kudos to the VA Medical System for doing this study and adds the following caveats: choose a facility and a surgeon with experience. We reiterate this point again and again in the podcast but it bears repeating: experience matters greatly when it comes to better outcomes in the majority of interventions.

Other topics this week include the best way to quit smoking in the Archives of General Psychiatry, which doctors are overusing Pap smears in Annals of Internal Medicine, and the best mask for preventing transmission of the influenza virus in JAMA. Until next week, y'all live well.

Aging and Cardiovascular Fitness

Cardiorespiratory Fitness Declines With Age, No Matter What

Here's the bad news: no matter what you do, what exercise regimen you adopt, how carefully you eat, the capacity of your heart and lungs, so-called cardiorespiratory fitness, will decline as you age. And the point of no return, when the decline happens much more sharply, is 45 years of age. That's in this issue of Archives of Internal Medicine: Role of Lifestyle and Aging on the Longitudinal Change in Cardiorespiratory Fitness.

We already knew that cardiovascular capacity diminished over time, with one very noteworthy study of male marathon runners demonstrating this fact with astonishing clarity. Now these researchers have examined data from almost 20,000 men and women (almost 35oo women!) enrolled in the Aerobics Center Longitudinal Study, including treadmill test results and data from comprehensive medical examinations. Study participants ranged in age from 20 to 96 years.

Results indicate that age 45 is the point of no return (shoot me now). That's when the rate of decline accelerates. Cofactors that make the decline even more precipitous include those well-known demons : smoking, obesity, and a sedentary lifestyle. People who did not smoke, didn't have a body mass index (BMI) greater than 25 and who exercised fairly strenuously on a regular basis preserved their cardiorespiratory fitness best. Clearly, the results indicate once again that you are in charge of your own health, and that choices you make will absolutely determine how well you age.

This last is also important from a societal perspective. People aged 80 and older comprise the fastest growing segment of our population, and we are all vested in how well they age, and how to keep them well until the end of life. The current healthcare debate has brought to the fore the fact that the biggest Medicare expenditures occur in the last six months of life. A generally healthier older population would likely reduce this outlay. Finally, more efforts need to be targeted toward prevention of obesity and smoking as well as adoption of a more active lifestyle in younger folks.

Other topics this week include risks related to use of so-called 'atypical antipsychotic' medications in children in JAMA, staving off type 2 diabetes in the Lancet, and the best insulin regimen for managing diabetes in NEJM. Until next week, y'all live well.