Chemotherapy (chemo) is a relatively new method of treating cancer. Most cancer-fighting drugs in use today have been developed in the last four decades.
Chemotherapy acts on cells that divide rapidly, which includes some tumor cells. The drugs interfere with division of the cell, the cell’s method of reproduction. If the cell is unable to reproduce, it will eventually die without another cell to replace it. The net effect, then, is a decreased number or tumor cells.
Unfortunately, chemotherapy also affects normal cells that divide rapidly. Normal cells most affected by these drugs are cells of the bone marrow, gastrointestinal tract, hair follicles, and some reproductive organ cells. That is why side effects of chemotherapy may include low blood cell counts, mouth sores, diarrhea, hair loss, infertility and others.
More than one chemotherapy drug may be given at a time. They appear to have additional effects when combined. The combination of drugs is given every three or four weeks. There is enough time between cycles for the blood counts to recover. Multiple cycles of the drug are given to destroy more cancer cells.
How Are the Medicines Given?
Chemotherapy can be given in different ways. The four most common methods are:
• Intravenous
• Oral
• Intramuscular
• Intrathecal
The method used is based on the actual disease diagnosed and the agent’s effectiveness.
The Intravenous (IV) route is a very common way of giving medicine directly into a vein. A small plastic needle is inserted into one of the veins in the lower arm. There is some discomfort during insertion because a needle stick is required to get into the vein. After that, administration of the medication is almost painless. Chemotherapy flows from a plastic bag, through the needle and catheter, into the bloodstream. Sometimes a syringe is used to push the chemotherapy through the tubing.
Chemotherapy medications taken orally can take the form of a tablet, capsule, or liquid. This is the easiest and most convenient medication route since it can be self-administered in the comfort of your home.
Intramuscular injections are administered in the muscle of the arm, thigh, or buttocks. There is a slight pinch as the needle is inserted, but the procedure lasts only a few seconds.
Certain types of leukemia have a tendency to spread to the nervous system. To prevent this, doctors may perform a spinal tap and inject a chemotherapy drug into the spinal fluid to destroy any disease cells. This is known as an intrathecal method of administration.
Permanent and Temporary Catheters
For some patients, IV insertions can eventually damage the veins of the arm. Some patients have small veins and some have very few veins appropriate for IV insertion. Frequent IV insertions and too small or too few veins may prompt the doctor to recommend a permanent type of IV catheter. Permanent catheters allow patients to go home and receive chemotherapy without needing other IVs placed. Along with receiving chemotherapy and IV fluids through this catheter, patients can receive blood products and have their blood drawn without painful needle sticks.
Some of the common types of permanent catheters are HICKMAN® catheter, BROVIAC® catheter, and GROSHONG® catheter. These catheters are made by C.R. Bard, Inc. and its related company, BCR, Inc. These catheters vary slightly in their structure, but all work in a similar manner.
Care of these catheters may be a little different, but the principle of insertion is similar. A rubber type of tube is surgically inserted into one of the central veins, commonly the external jugular vein. While under general or local anesthesia, the tube is tunneled through surface skin tissue between the neck and shoulder to another separate incision, usually on the chest or stomach wall. The entrance site will have stitches and a small bandage to facilitate healing. The exit site for the catheter is easy to see and care for since patients must change their dressings three times a week to prevent infection.
To prevent clotting within the catheter, the device must be flushed daily with heparin, which is a blood thinning and cleansing agent. Many patients learn to care for their catheter while in the hospital. The nurse will thoroughly and clearly instruct the patient or patient’s family members in appropriate care for the device. When not in use, Groshong catheters do not require heparin flushes but instead require a saline flush weekly.
Another type of permanent catheter to a central vein is known as the implanted port. It is round in shape and surgically inserted under the skin surface on the chest wall between the neck and shoulder area. A nurse will insert a needle through the top skin surface to gain access to the vein. The chemotherapy can then be give through the catheter as if it were an IV in the arm. As with the Hickman catheter, blood can be removed and received through this device. There is no homecare required for a port, but the device must be flushed once a month by your oncology nurse.
There is a temporary venous access device for administering chemotherapy that is called a PICC line. This is placed in your arm, usually through a vein on the inside aspect of your elbow. This is usually placed by the radiology department as an outpatient procedure. The PICC line is utilized for short courses of chemotherapy, usually up to six weeks. The exit site needs to have dressing changes to avoid infection. The catheter is flushed with heparinized saline after each use, as well as once a week.
Intrathecal chemotherapy can be given through what is called an Omaya reservoir. This device is surgically inserted under the scalp for direct injection of chemotherapy throughout the spinal fluid. The drugs are then given through the reservoir, rather than through the back during a spinal tap.
