DOPPLER ULTRASOUND

A Doppler ultrasound test uses reflected sound waves to evaluate blood as it flows through a blood vessel. It helps doctors evaluate blood flow through the major arteries and veins of the arms, legs, and neck. It can show blocked or reduced blood flow through narrowing in the major arteries of the neck that could cause a stroke. It also can reveal blood clots in leg veins (deep vein thrombosis, or DVT) that could break loose and block blood flow to the lungs (pulmonary embolism). See an illustration of a stroke or an embolus.
During Doppler ultrasound, a handheld instrument (transducer) is passed lightly over the skin above a blood vessel. The transducer sends and receives sound waves that are amplified through a microphone. The sound waves bounce off solid objects, including blood cells. The movement of blood cells causes a change in pitch of the reflected sound waves (called the Doppler effect). If there is no blood flow, the pitch does not change. Information from the reflected sound waves can be processed by a computer to provide graphs or pictures that represent the flow of blood through the blood vessels. These graphs or pictures can be saved for future review or evaluation. See an illustration of a Doppler ultrasound.

The four types of Doppler ultrasound are:

1. “Bedside” or continuous wave Doppler. This type uses the change in pitch of the sound waves to provide information about blood flow through a blood vessel. The doctor listens to the sounds produced by the transducer to evaluate the blood flow through an area that may be blocked or narrowed. This type of ultrasound can be done at the bedside in the hospital to provide a rapid estimate of the extent of blood vessel damage or disease.
2. Duplex Doppler. Duplex Doppler ultrasound uses standard ultrasound methods to produce a picture of a blood vessel and surrounding organs. In addition, a computer converts the Doppler sounds into a graph that provides information about the speed and direction of blood flow through the blood vessel being evaluated.
3. Color Doppler. Color Doppler uses standard ultrasound methods to produce a picture of a blood vessel. In addition, a computer converts the Doppler sounds into colors that are overlaid on the image of the blood vessel and that represent the speed and direction of blood flow through the vessel.
4. Power Doppler. Power Doppler is a newer ultrasound technique that is up to five times more sensitive in detecting blood flow than color Doppler. Power Doppler can obtain some images that are difficult or impossible to obtain using standard color Doppler. However, power Doppler is most commonly used to evaluate blood flow through vessels within solid organs. Blood flow in individual blood vessels is most commonly evaluated by combining color Doppler with duplex Doppler. Together, they are able to provide better information on the direction and speed of blood flow than when these techniques are used individually.

How It Is Done

This test is done by a doctor who specializes in performing and interpreting imaging tests (radiologist) or by an ultrasound technologist (sonographer). It is done in an ultrasound room in a hospital or doctor's office.
You will need to remove any jewelry that might interfere with the Doppler ultrasound scan. You may need to take off all or most of your clothes, depending on which area is being examined (you may be allowed to keep on your underwear if it does not interfere with the test). You will be given a cloth or paper covering to use during the test.
For abdominal scans, you will lie on your back.
For chest scans, you will lie on your back with your neck slightly extended.
For head and neck scans, your head may be turned to one side.
For an arm or leg scan, your head is slightly raised and the exposed arm or leg is turned slightly outward. Occasionally for a leg scan, you may be asked to lie on your stomach.
Gel is applied to the skin to promote the passage of the sound waves. The transducer is placed in the gel and moved along the skin. You need to lie very still during the procedure. You may hear sounds that represent the flow of blood through the blood vessels.
The test usually takes 30 to 60 minutes.

Home Nebulizer Therapy

What is a nebulizer ?

A nebulizer changes liquid medicine into fine droplets (in aerosol or mist form) that are inhaled through a mouthpiece or mask. Nebulizers can be used to deliver bronchodilator (airway-opening) medicines such as albuterol (Ventolin, Proventil or Airet) or ipratropium bromide (Atrovent).

A nebulizer may be used instead of a metered dose inhaler (MDI). It is powered by a compressed air machine and plugs into an electrical outlet. Portable nebulizers, powered by an internal battery or cigarette lighter, are available for individuals requiring treatments away from home.

Nebulizer care guidelinesYour home care company will show you how to use the nebulizer. You will need the following supplies to give the nebulizer treatment:

• Air compressor
• Nebulizer cup
• Mask or mouthpiece
• Clean eye droppers or other measuring devices to dispense the medication

Treatment procedure

1. Place the air compressor on a sturdy surface that will support its weight. Plug the cord from the compressor into a properly grounded (three prong) electrical outlet.
2. Wash your hands with soap and warm water, and dry completely with a clean towel.
3. Carefully measure the medicine exactly as you have been instructed. Use a separate, clean measuring device (eyedropper or syringe) for each medicine.
4. Remove the top part of the nebulizer cup, as shown to the left.
5. Place your medicine in the bottom of the nebulizer cup, as shown to the right.
6. Attach the top portion of the nebulizer cup and connect the mouthpiece or face mask to the cup.
7. Connect the tubing to both the aerosol compressor and nebulizer cup.
8. Turn on the compressor with the on/off switch. Once you turn on the compressor, you should see a light mist coming from the back of the tube opposite the mouthpiece as shown to the left.
9. Sit up straight on a comfortable chair.
10. If you are using a mask, position it comfortably and securely on your face as shown to the right.
11. If you are using a mouth piece, place it between your teeth and seal your lips around it as shown to the left..
12. Take slow, deep breaths through your mouth. If possible, hold each breath for two to three seconds before breathing out. This allows the medication to settle into the airways.
13. Continue the treatment until the medication is gone (about seven to 10 minutes).
14. If you become dizzy or feel "jittery," stop the treatment and rest for about five minutes. Then continue the treatment, but try to breathe more slowly. If these symptoms continue with future treatments, inform your health care provider.
15. Turn the compressor off.
16. Take several deep breaths and cough. Continue coughing and try to clear any secretions you might have in your lungs. Cough the secretions into a tissue and dispose of it properly.
17. Wash your hands with warm water and soap, and dry them with a clean towel.

Care of nebulizerCleaning and disinfecting your equipment is simple, yet very important.Cleaning should be done in a dust- and smoke-free area away from open windows.

Here is how to clean your equipment:

1. After each treatment, rinse the nebulizer cup with warm water, shake off excess water and let it air dry.
2. At the end of each day, the nebulizer cup, mask, or mouthpiece should be washed in warm, soapy water using a mild detergent, rinsed thoroughly, and allowed to air dry.Note: There is no need to clean the tubing that connects the nebulizer to the air compressor.
   Do not put these parts in the dishwasher.
3. Every third day, after washing your equipment, disinfect the equipment using a vinegar/water solution or the disinfectant solution your supplier suggests.
   To use the vinegar solution, mix 1/2 cup white vinegar with 1-1/2 cups of water. Soak the equipment for 30 minutes and rinse well under a steady stream of water. Shake off the excess water and allow to air dry on a paper towel. Always allow the equipment to completely dry before storing in a plastic, zipper storage bag.
   Compressor care
   Cover the compressor with a clean cloth when not in use. Keep it clean by wiping it with a clean, damp cloth as needed.
   Do not put the air compressor on the floor either for treatments or for storage.
   Check the air compressor's filter as directed. Replace or clean according to the directions from your equipment supplier.
   Always have an extra nebulizer cup and mask or mouthpiece in case you need it.
   Store your medicines in a cool, dry place. Check them often. If they have changed color or formed crystals, throw them away and replace them with new ones.
   All equipment for your nebulizer therapy can be obtained through your equipment supplier.
   Important: Unplug the compressor before cleaning it.