How long is needed to hold pressure on the draw site if it is suspected that an artery was nicked?

Definition

An arterial stick is the collection of blood from an artery for laboratory testing.

Alternative Names

Blood sample - arterial

How the Test Is Performed

Blood is usually drawn from an artery in the wrist. It may also be drawn from an artery on the inside of the elbow, groin, or other site. If blood is drawn from the wrist, the health care provider will usually first check the pulse. This is to make sure blood is flowing into the hand from the main arteries in the forearm (radial and ulnar arteries).

The procedure is done as follows:

  • The area is cleaned with antiseptic.
  • A needle is inserted. A small amount of anesthetic may be injected or applied before the needle is inserted.
  • Blood flows into a special collecting syringe.
  • The needle is removed after enough blood is collected.
  • Pressure is applied to the puncture site for 5 to 10 minutes to stop the bleeding. The site will be checked during this time to make sure the bleeding stops.

If it is easier to get blood from one location or side of your body, let the person who is drawing your blood know it before starting the test.

How to Prepare for the Test

Preparation varies with the specific test performed.

How the Test will Feel

Puncture of an artery may be more uncomfortable than puncture of a vein. This is because arteries are deeper than veins. Arteries also have thicker walls and have more nerves.

When the needle is inserted, there may be some discomfort or pain. Afterward, there may be some throbbing.

Why the Test Is Performed

Blood transports oxygen, nutrients, waste products, and other materials within the body. Blood also helps control body temperature, fluids, and the balance of chemicals.

Blood is made up of a fluid portion (plasma) and a cellular portion. Plasma contains substances dissolved in the fluid. The cellular portion is made up mainly of red blood cells, but it also includes white blood cells and platelets.

Because blood has many functions, tests on the blood or its components may give valuable clues to help providers diagnose many medical conditions.

Blood in the arteries (arterial blood) differs from blood in the veins (venous blood) mainly in its content of dissolved gases. Testing arterial blood shows the makeup of the blood before any of its contents are used by the body tissues.

Normal Results

Normal value ranges may vary slightly among different laboratories. Talk to your provider about the meaning of your specific test results.

What Abnormal Results Mean

An arterial stick is done to get blood samples from arteries. Blood samples are mainly taken to measure gases in the arteries. Abnormal results may point to breathing problems or problems with the body's metabolism. Sometimes arterial sticks are done to get blood culture or blood chemistry samples.

Risks

There is little risk in having your blood taken. Veins and arteries vary in size from one person to another and from one side of the body to the other. Taking blood from some people may be more difficult than from others.

Other risks associated with having blood drawn are slight but may include:

  • Excessive bleeding
  • Fainting or feeling lightheaded
  • Hematoma (blood accumulating under the skin)
  • Multiple punctures to locate veins
  • Infection (a slight risk any time the skin is broken)

There is a slight risk for damage to nearby tissues when the blood is drawn. Blood can be taken from lower-risk sites, and techniques can be used to limit tissue damage.

References

Eiting E, Kim HT. Arterial puncture and cannulation. In: Roberts JR, Custalow CB, Thomsen TW, eds. Roberts and Hedges' Clinical Procedures in Emergency Medicine and Acute Care. 7th ed. Philadelphia, PA: Elsevier; 2019:chap 20.

Smith SF, Duell DJ, Martin BC, Gonzalez L, Aebersold M. Specimen collection. In: Smith SF, Duell DJ, Martin BC, Gonzalez L, Aebersold M, eds. Clinical Nursing Skills: Basic to Advanced Skills. 9th ed. New York, NY: Pearson; 2016:chap 20.

A pressure bandage (also called a pressure dressing) is a bandage that’s designed to apply pressure to a particular area of the body.

Typically, a pressure bandage has no adhesive and is applied over a wound that’s been covered with an absorbent layer. The absorbent layer may or may not be held in place with an adhesive.

Pressure bandages are used to control bleeding and encourage blood clotting without constricting normal blood circulation. They help:

  • minimize swelling
  • protect the wound from contamination
  • protect the injured area from additional trauma
  • prevent heat and fluid loss

Keep reading to learn when and how to apply a pressure bandage as well as precautions.

Doctors often use pressure bandages following surgical procedures. They’re also used by emergency medical responders.

Initial wound treatment

If you or someone you’re with has a deep wound that’s profusely bleeding, you may need to apply a pressure bandage. But first, here are the initial steps you should follow:

  1. Call for emergency medical help to come to you, or decide how to get the wounded person to emergency medical help.
  2. If necessary, expose the entire wound by removing any clothing around it. You may have to cut the clothing away. If any clothing is stuck to the wound, work around it.
  3. Don’t try to wash the wound or remove any objects that have been impaled.
  4. Apply a dressing over the wound. If you don’t have a first aid kit with sterile, nonstick gauze, use the cleanest, most absorbent cloth you have.
  5. Fold a 3-foot length of cloth into a ribbon about 4 inches wide and tightly but gently wrap it around the limb, then tie it off with a secure but easily adjustable knot. The knot should be over the nonaffected part of the limb, not over the wound.
  6. Look for signs that you’ve tied the bandage too tightly. For example, if the injured limb is turning blue or becoming cool, slightly loosen the bandage.
  7. Elevate the wound above the injured person’s heart. If broken bones are involved, you’ll need to splint the limb before elevating it.
  8. Use your hand to apply manual pressure to the wound for 5 to 10 minutes.

At this point, the wound should be more stable. However, if you see blood soaking through the bandage or dripping out from underneath it, you need to apply a more effective pressure bandage to prevent excessive blood loss.

Excessive blood loss can result in:

  • a drop in blood pressure
  • a drop in blood volume
  • heart rate or rhythm abnormalities
  • a low oxygen saturation
  • unconsciousness
  • death

If elevation, gauze, and manual pressure haven’t adequately stopped the bleeding, here are your next steps:

  1. If the injured person’s wound is stabilized and they’re fully awake, have them drink liquids to help replace blood volume.
  2. Use strips of cloth, cut from clothing if necessary, to make a pressure bandage.
  3. Wad up some strips and put them over the wound.
  4. Wrap a longer piece of cloth around the limb and the wad of strips and tie the ends together. You want the pressure to be enough to stop the bleeding, but not so tight as to act as a tourniquet (completely cut off the blood supply to the area). As a tightness test, you should be able to fit your finger under the knot.
  5. As an alternative to the steps above, if available, you can also use an elastic pressure bandage, like an ACE wrap, placed over gauze and an underlying absorptive bandage pad.
  6. Check the injured person’s toes and fingers further beyond the pressure bandage to make sure the bandage isn’t too tight. If they’re not warm and pink, loosen the bandages.
  7. Check often to make sure bleeding has stopped.
  8. If you see signs of decreased circulation in the limb (pale or blue, cool, numb), loosen the bandage.

You can also use a pressure bandage to treat venomous snake bites.

According to Queensland Children’s Hospital, applying firm pressure over the blood vessels at the site of the poisonous snake bite can slow the venom from progressing into the bloodstream.

If the pressure bandage is tied too tightly around an extremity, the pressure bandage becomes a tourniquet.

A tourniquet cuts off the blood supply from the arteries. Once that blood supply has been cut off, the tissues separated from oxygen-rich blood flow — such as the nerves, blood vessels, and muscles — can be permanently damaged and result in loss of the limb.

If you’ve applied a pressure bandage, continually check around it to make sure you haven’t tied it too tightly or swelling hasn’t made it too tight, but try to maintain a proper amount of pressure.

For some wounds, a pressure bandage may be used to help control bleeding and better allow the blood to clot over a wound.

It’s important, however, for a pressure bandage not to be too tight, as you don’t want it to halt blood flow from the arteries.

You can also use pressure bandages in the treatment of venomous snake bites to help stop the venom from getting into the bloodstream.

How long do you hold pressure after drawing blood?

Leave the pressure bandage on your needle site for 3 to 6 hours after your procedure. Avoid activities that may strain the arm used during your procedure (such as exercise and heavy lifting) for at least 1 day after your procedure.

How long should the puncture site be pressed after arterial puncture?

Avoid checking the puncture site until local pressure has been maintained for at least 5 minutes. In patients who have a coagulopathy or are on anticoagulation therapy, it may be necessary to apply local pressure for a longer time. Check for hemostasis, and apply an adhesive bandage over the puncture site.

How long should pressure be applied to a venipuncture?

Pressure, applied with a gauze pad, must continue at the site as long as necessary to stop the bleeding. Wrap a gauze bandage tightly around the arm to keep the pad in place and tell the client to leave the bandage on the site for at least 15 minutes.

What is the minimum amount of time that pressure must be applied to the venipuncture site immediately after blood collection to prevent hematoma formation?

As soon as a hematoma is noted, remove the needle and tourniquet and apply pressure at the site for a minimum of 3 minutes. Check the site and if the hematoma has stopped forming, put on a bandage or gauze with tape and inform the patient of the hematoma. The bandage should remain in place for a minimum of a half hour.