a soft rubber drain called a Penrose in a wound or in the subcutaneous tissue to keep a wound open and allow infection to dissipate. Drains, if left long enough, will form a tract so that, when they are removed, an opening is still left through which fluids such as bile or pus can drain if needed. It usually takes about seven to ten days to form a tract, so that's how long we usually leave drains in an area of infection.
Sometimes a seroma, which is a collection of watery fluid or hematoma, may form several days after surgery, and a patient will need to have this aspirated with a needle and syringe. If the fluid collection recurs, then a drain can be placed under a local anesthetic. This can happen in areas such as the axilla or armpit after lymph node dissection, or after some big hernia operations, when artificial mesh is used to close a weak abdominal wall.
When drains, small or large, are removed, the surgeon will usually give the patient some pain medication before pulling the tube, although most times the procedure is almost painless.
Another method of closing skin or connective tissue is by the use of staples. These may vary tremendously in size and shape, but for the most part they look like staples in a paper stapler. They can be used for closing skin incisions, especially when infection is present and, generally, they leave a very clean incision.
Whereas years ago intestines had to be sewn together in two layers in a tedious procedure, today we have stapling apparatus that can connect one loop of intestine to another in less than a minute, and do so in a more exacting fashion than a surgeon could accomplish with a needle and thread. In laparoscopic surgery (see Chapter 15), special staplers have been devised to clip off blood vessels and the gall bladder duct, to amputate the appendix, and staple off the fallopian tube in a tubal ligation. Neurosurgeons use staplers to clamp off aneurysms in the brain, and general surgeons routinely use staplers to occlude blood vessels in many types of surgery, such as thyroid resections, hernias, liver and spleen surgery. There is even a special device that ligates or ties off, divides and staples tissue in one motion, called the LDS stapler. There are staplers that can connect two loops of colon together end-to-end and even connect blood vessels end-to-end.
The field of mechanization continues to improve each year and makes surgery safer, more rapid and less risky for the patient and the surgeon alike.
Chapter 25
LABORATORY VALUES
You may not want to be a number
But you are, ain't that a bummer.
And if you don't have pretty data,
Well, you're just a second rater!
Face it. We're just a large accumulation of chemicals. Suffice it to say the status of our bodies is often wrapped up in laboratory values, so you might as well know what the major ones stand for! It's not my intention to describe all the laboratory data, but rather to give you the most common ones and show how they reflect what's going on in your body. It may seem boring, but then give it a try. If you don't like it, go on to the next chapter!
First, there's the CBC or complete blood count. This includes the hemoglobin and hematocrit, which measure the amount of red blood cells (RBC's) in the bloodstream. These cells carry, among other things, oxygen to the cells to keep you alive. Normal values of hemoglobin (Hg) range from 1315 grams, and all these values will vary with sex, age, and body habitus; hematocrit (Hct) should be about three times the hemoglobin, or 39 to 45%. Lowered Hct and Hg will indicate acute or chronic blood loss or other conditions, including malnutrition, cancer, or deficiency in the bone marrow, where blood is made, or in the building products of blood, such as calcium (Ca). It is usually the first laboratory data your doctor looks at. The sedimentation rate of red cells (sed rate) is a vague estimation of disease, but can be used to monitor certain illnesses, recurrent disease, or responses to medications; it is normally in the range of 1020.
Included in the CBC is the WBC or white blood count, which is a measure of many different types of blood cells, as long as they're not red, including polys, monocytes, eosinophils, and basophils. The important thing is that, when there is an elevation of the WBC above the normal range of 3,0009,000, it may mean something's going on, such as infection or acute or chronic disease. Usually, the higher the WBC, the more serious the situation! As an example, in appendicitis the WBC may be anywhere from normal to 14,000 or more; with a ruptured appendicitis, where the appendix has burst and caused peritonitis and severe infection, the WBC may be into the 20,000 range. Certain malignancies can cause marked reduction or marked elevation of the WBC. The WBC level is used to monitor the cancer patient's response to some chemotherapeutic agents. The WBC is one measure of our ability to fight off infection. In patients with AIDS or on chemotherapy, the level may drop below 1000 and place the individual at high risk for severe systemic infections. The CBC also includes the platelet count (see Chapter 18), which should normally be in the range of 200,000 to 400,000/mm3. When levels get below 40,000, then bleeding can occur, and the patient may need platelet transfusions!
Other blood studies also relate to blood clotting. The bleeding time should be about 4 minutes. If it's prolonged, you may have a bleeding problem. The PT and PTT are special measures of coagulation, and all that's important is that PT should be about 1214 seconds, and PTT should be about 45 seconds. Anticoagulants, such as coumadin, will cause the PT to be elevated, and heparin will cause the PTT to be elevated. The physician must monitor these values to make sure that your blood is not too thin when you are taking these medicines.
Urinalysis is another important study and includes measurement of blood in the urine, since normally there should be none; this may indicate lab error, infection, kidney stone, or malignancy. Pus in the urine indicates a urinary tract infection. BUN (blood urea nitrogen) and creatinine (Cr) help us evaluate kidney function with normal BUN about 718 and Cr about 0.20.8.
Bilirubin is one of the breakdown products of blood and measures the ability of the liver to function properly. An elevated bilirubin may mean liver disease, but is also elevated with gall bladder disease when a gallstone is blocking the main bile duct (see chapter on Gall Bladder and Bile Ducts) or when there is leakage of bile after gall bladder surgery. Normal bilirubin is about 0.1 to 1.1, although there are certain people who have elevated bilirubin because of a strange, otherwise asymptomatic disease called Gilbert's disease. Your doctor knows all about these things. Calcium, Ca, and phosphorus (P) are important chemicals in bone strength, and Ca is important in blood clotting. The blood levels of these elements are controlled by small glands in the neck behind the thyroid gland called the parathyroid glands. There are several benign and malignant diseases of these glands which may be indicated by an elevated Ca and a lowered P. Also, since Ca is used in blood coagulation, when there has been a lot of bleeding and blood clotting, the Ca level may fall. Normal Ca is 911 and normal P is 24.
Amylase and lipase are enzymes or chemicals in the blood secreted predominately by the pancreas. Elevations of these may indicate pancreatitis (see Pancreas) or inflammation in an organ near the pancreas, such as the liver or gall bladder. Amylase normally is 25125, but may rise into the thousands with pancreatitis and, similarly, lipase, which is normally about 23208, can get as high as 20,000 in active disease.
We have already discussed blood type and crossmatching in Chapter 18. We can get blood samples and obtain specific blood products that a person needs rather than just giving “whole” blood. These products include fresh frozen plasma, platelet concentrate, cryoprecipitate, and other complex blood products that's why we have special physicians called hematologists to sort out the problem.
SGOT, normal level 540, SGPT, normal 756, and LDH, normal 100190, are substances which indicate liver disease. It is a complex subject, and all you need to know is that, when they are elevated, the physician has to determine which of many diseases are present, such as hepatitis, cirrhosis, malignancy, bile duct obstruction or a whole host of other diseases. Alkaline phosphatase, normal range
