Monday, July 19, 2010

Anatomy Lab

Medical Meanderings 10 June 2009

Cutting Up ©

“He lived for others, he died for us.”
Common epigraph written on dissection tables circa 1900.

I clearly remember the first day of anatomy class, the second day of medical school in the summer of 1995. A large group of us, mostly new college graduates, stood nervously outside the anatomy lab doors. Although no one had told us to be quiet, we whispered with strangers who would soon be our lab partners. After a brief introduction from our professor regarding the layout of the anatomy lab, the textbook we’d be using, the location of the bathroom and so on, the big doors were opened and we filed in.

My three partners and I found our “humidor”: the metal table with two heavy, hinged doors in which the cadaver was kept. The doors were unlatched and carefully swung downward under the table. On the table was a white body bag with, obviously, a body in it.

When instructed, one of us (not me) unzipped the body bag, loosing a strong whiff of phenol and formalin preservative. The thin plastic was rolled back, and the petite 73-year old woman, whom we would come to know intimately, was exposed. She was on her back, naked, with face, hands and feet wrapped in moistened gauze to preserve them until that part of dissection—and to preserve our emotions for now. Her hair was shaved off, a fact that surprised me until I reflected on its necessity here. Her skin had an unnaturally firm, plastic look from the embalming process, which had also created many wrinkles as it dissolved some of her scarce body fat.

We started with her upper extremity—the arm. Two of us dissected each arm, one reading instructions and the other cutting. The first cuts were unnerving—we expected her to flinch, or bleed, or cry out, but of course skin is simply a material thing when life has left it. In a few days, we became comfortable learning to separate skin from muscle, ligament from tendon, nerve from artery. The details were overwhelming, the names foreign and functions complex. It didn’t take long to become so absorbed that we often forgot the arm we were exploring had hugged and waved goodbye.

From the upper extremities, we moved on to the chest and the back (which required the unexpectedly difficult task of turning her face-down). The head and neck required dissection of the face, another emotionally troubling task. Finally, we explored the pelvis and the lower extremities. Our cadaver was slowly disassembled into her component tissues, which were meticulously kept together. Finally, when we had learned all we could and passed the final examination, her 73-year old remains were cremated together, and given to her family for burial at a yearly ceremony held at the medical school.

Why, in this age of computer simulation, must doctors-to-be dissect human bodies? Because the feel of a nerve compared to an artery cannot be well-simulated. Because human beings vary more than books or programs can comprehend. Finally, because to help the living, the presence of death must not be as unnerving as it was to all of us uninitiated novices on that first day.


Medical Meanderings

Rub A Dub Dub (c)

In 1847, a young medical professor in Vienna, Austria, named Ignaz Semmelweis went to visit a sick friend. His friend, Jakob Kolletschka, was near death with a high fever, rapid pulse and sweats. Jakob had become sick soon after knicking one of his fingers while doing an autopsy and as Ignaz stood by his friend’s bed, watching him die decades before germ theory and antibiotics, Ignaz had a stunning insight: He had seen this disease before…in pregnant women.

Semmelweis had been troubled for years by the high death rate from “puerperal fever” in pregnant women in his hospital, where 13% of those admitted in labor died before hospital discharge. In a nearby obstetrical hospital run by midwives instead of physicians, the maternal death rate was only 2%. Now his friend Jakob had an illness very similar to puerperal fever from dissecting a dead body, and Semmelweis made a connection that would change medical practice forever.

Semmelweis had noticed that medical students would move from the autopsy room to the delivery room, wearing the same clothing and without washing their hands. On a hunch, he set up a policy: No one will be allowed to deliver a baby without first cleaning his hands in a chlorine solution. The death rate from puerperal fever on the labor and delivery ward dropped quickly to two percent.

Hand washing is the most basic weapon in the war against infectious disease. When done correctly, it can reduce the spread of many diseases. Unfortunately, it is rarely done correctly—in one study, 90% of hospital staff washed their hands for less than 10 seconds, instead of 15-30 seconds recommended by the Centers for Disease Control. Even in study situations, where people are being observed for compliance, only 40% of hospital staff washed their hands as they should have. Also, frequent hand washing is tough on the skin, causing changes in the types of germs present, and damaging the skin, possibly leading to a higher risk of transmitting infection.

Nowadays, alcohol hand rubs are becoming more widely accepted as the best way to clean hands. Alcohol hand rubs containing kill 90% or more of bacteria, viruses and fungi on the hands and reduce the risk of disease transmission from 92% with hand washing to 17%. Alcohol hand rubs work by breaking apart proteins in germs, and they work almost immediately. Also, they save time—whereas hand washing takes up to 30 seconds, the average alcohol hand rub is used in only 10 seconds. If you clean your hands five times a day, you will save 10 hours per year with a hand rub—that’s more than a full work day (or a good night’s sleep!).

Either way, by soap or by alcohol rub, in this season of colds, flu and strep, clean your hands early and often. Make Semmelweis proud. His insight, after all, eventually got him fired when the hospital administrator felt the policy change to be a criticism of his management. Science marches on, office politics doesn’t.

Ear Wax

Medical Meanderings 15 October 2008

Waxing Eloquent ©

If your head is wax, don’t walk in the sun.
Benjamin Franklin (1706-1790)

Ear wax is beautiful stuff. Medical types call ear wax “cerumen,” from the Latin word “cera,” meaning wax. Cerumen is a complicated mixture of secretions and debris produced by the outside third of our ear canals. The secretions include sebum, the same oily chemical that, when eaten by bacteria in our armpits, gives us the distinctive odor of locker rooms. Also, specific glands called ceruminous glands secrete the long chains of fat molecules that make ear wax so…waxy.

The sebum and wax mix with whatever passes by in the ear canal, including dead skin cells, bacteria living on our skin, water and occasional hairs. This mixture can range in texture from liquid to a rock-hard, and in color from a reddish-black to white. The characteristics of our cerumen depend on its specific composition and on how long it’s been sitting in the ear canal. The texture and color of our ear wax, however, doesn’t necessarily tell us much about how the ear canal is working.

The wax is moved outward from the ear canal by a lining of hair cells, by the movement of the tissues around our jaw joint, and by the normal growth of skin in the canal. The point of knowing this is: we do NOT need cotton-tipped swabs! The ear canal comes with standard equipment that moves the wax out, unless we do something (like sticking in a swab) that destroys the lining cells or packs the wax in more deeply or tightly. All we do with those swabs, toothpicks, paper clips or whatever else we stick in our ears is damage the system that would clean our ears out all on its own.

Cerumen has several important roles in keeping the ears healthy. First, it traps dust, skin, hair and insects that would otherwise plug up our ear canals in a few months, and moves that garbage out. Second, it absorbs water that would, if allowed to stay in the canal, form a home for bacteria to grow and infect us. Third, it is thought to have acted as an insect repellant back when our ancestors slept on the ground.

Getting rid of impacted ear wax is not something to try at home. Serious, sometimes permanent damage can be done to the ears during botched attempts to dig ear wax out. Leave it to the professionals, who have several methods of attacking this difficult problem. Drops that soften ear wax (e.g., mineral oil) are helpful. We will use cerumen spoons or curettes to carefully pull wax out. Water irrigation often works, and if all else fails, suction devices may work. There is no scientific evidence that “ear candling” is useful in removing ear wax, and it cannot be recommended.

The easiest way to maintain the health of your ear canals is to leave them alone. If it’s too late for that, then simply placing two drops of mineral oil in each ear once a week, occasional irrigation of the ear in the shower, and avoiding cotton swabs is all you need to do.