December 21, 2003

Health Research

Respiratory Viral Infections:

Influenza is a viral infection that attacks your respiratory system, including your nose, throat, bronchial tubes and lungs.

Antibiotics are intended for bacterial infections, not for viral infections such as colds, coughs or the flu.


My doctor has prescribed antibiotics three times now in the past 8 weeks, with the last prescription being a powerful (and expensive) broad-spectrum antibiotic. He suggested if this doesn't clear it up in 2 weeks the next step would be an MRI of my sinuses. I think he suspects something like polyps. Of course I'm not a doctor, but my sinuses don't bother me like my lungs do, I wonder if a chest X-ray might be more appropriate.

Pulmonary Edema:


Your lungs contain millions of small, elastic air sacs called alveoli. With each breath, these air sacs take in oxygen and release carbon dioxide, a waste product of metabolism. Normally, the exchange of oxygen and carbon dioxide takes place without problems. But sometimes increased pressure in the blood vessels in your lungs forces fluid into the air sacs, filling your lungs with fluid and preventing them from absorbing oxygen — a condition called pulmonary edema.

In most cases, heart problems are the cause of pulmonary edema. But fluid can accumulate in your lungs for other reasons, including lung problems such as pneumonia, exposure to certain toxins and medications, and climbing or living at high altitudes

Noncardiac pulmonary edema

Not all pulmonary edema is the result of heart disease. Fluid may also leak from the capillaries in your lungs' air sacs because the capillaries themselves become more permeable or leaky, even without the buildup of back pressure from your heart. In that case, the condition is known as noncardiac pulmonary edema because your heart isn't the cause of the problem. Some factors that can cause increased capillary permeability leading to noncardiac pulmonary edema are:


  • Lung infections. When pulmonary edema results from lung infections, such as pneumonia, the edema occurs only in the part of your lung that's inflamed.
  • Exposure to certain toxins. These include toxins you inhale — such as chlorine, ammonia or nitrogen dioxide — as well as those that may circulate within your body. For example, women giving birth may develop pulmonary edema when amniotic fluid reaches the lungs through the veins of the uterus (amniotic fluid embolism).
  • Severe allergic reactions (anaphylaxis). You can have serious allergic reactions to some medications as well as to certain foods and insect venom.
  • Smoke inhalation. Children and older adults are especially vulnerable to lung damage caused by breathing harmful vapors and gases in smoke from structural fires. The smoke from these fires often contains chemicals that irritate the lining of the lungs, causing the tiny blood vessels to leak.
  • Near-drowning and drowning.
  • Drug overdose. Drugs ranging from narcotics, such as heroin, to aspirin can cause noncardiac pulmonary edema. Aspirin-induced pulmonary edema can occur in people who take increasingly large doses of aspirin to relieve pain or other symptoms. For reasons that aren't clear, smokers who use aspirin are at greater risk.
  • Acute respiratory distress syndrome (ARDS). This serious disorder, which affects hundreds of thousands of people every year, occurs when your lungs suddenly become unable to take in enough oxygen. More than 30 conditions can cause ARDS, including severe injuries (trauma), systemic infection (sepsis), pneumonia or shock. ARDS sometimes also develops after extensive surgery. Symptoms usually appear within 24 to 72 hours after the original illness or trauma.
  • High altitudes. Mountain climbers and people who live in or travel to high-altitude locations run the risk of developing high-altitude pulmonary edema (HAPE). This condition — which typically occurs at elevations above 8,000 feet — can also affect skiers who start exercising at higher altitudes without first becoming acclimated. But even people who have hiked or skied at high altitudes in the past aren't immune. Although the exact mechanism isn't completely understood, HAPE seems to develop as a result of increased pressure from constriction of the pulmonary capillaries. Symptoms include headaches, insomnia, fluid retention, cough and shortness of breath. Without appropriate care, HAPE can be fatal.


This interests me because while reading Ned Overend's book "Mountain Bike Like a Champion", he warns about pulmonary edema. My illness began following the October 26th mountain bike race in Farmington. I've never competed at high altitude, but I wonder if the over-50 athlete in a 2-hour mountain bike race in a cold and wet climate might create a similar form of respiratory distress or damage the pulmonary capillaries in some way.

This article also mentions Asprin-induced pulmonary edema, while I only take a normal dose before a race, I often take a No-doz, coffee, or caffinated gel prior to the event. Can this combination cause a health risk?

Posted by dancoy at December 21, 2003 10:35 AM
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