TECHNIQUE

Blood Sampling Bears (Disease Investigation & Management - Treatment and Care)

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Summary Information
Type of technique Health & Management / Disease Investigation & Management / Techniques:
Synonyms and Keywords --
Description Sampling of blood from an accessible vein. 

Note: Different individuals prefer use of different veins, including the jugular, femoral, medial saphenous, cephalic and ventral glossal veins. Accessibility may vary by species and circumstance, and may be improved by clipping the hair over the vein. Suggestions include:

Vacutainer handling
  • Screw a Vacutainer needle onto the holder.
  • Insert a Vacutainer blood tube into the holder and push it lightly onto the needle, so it is just held in place, but the needle does not go through the rubber top into the tube (if it does, the vacuum will be lost).
  • Once the needle is in the vein, push the Vacutainer tube firmly onto the needle, so that the needle fully punctures the rubber top of the Vacutainer.
    • Do not withdraw the needle from the bear once the Vacutainer seal is punctured, or the tube will fill with air. (V.w5)
  • To fill more than one tube, keeping the needle and Vacutainer in place, pull the Vacutainer tube off and replace it with another one. (D249.w10)
  • Take care when changing tubes to hold the needle stead in the vain and not to puncture the far side of the vein. (D249.w10)

(D249.w10)

From the tongue vein (lingual vein)
  • Pull the bear's tongue out the side of its mouth and let it dry in the air.
  • Hold the tongue firmly in one hand, with the underside of the tongue uppermost and the body of the tongue over the palm of your hand. 
  • With the thumb of that hand, apply pressure across the vein at the base of the tongue so the vein becomes distended.. (D249.w10)
  • Carefully insert the needle, bevel upwards, into the vein at a 10-20 degree angle (D249.w10) and with the bevel of the needle upwards (V.w5)
  • If using a Vacutainer, keep the vacutainer holder firmly in place using the little and ring fingers of the hand holding the tongue, then use the thumb of the other hand to push the vacutainer tube firmly onto the needle.
    • Do not withdraw the needle from the bear once the vacutainer seal is punctured, or the tube will fill with air. (V.w5)
  • If using a syringe, draw back on the plunger, taking care not to pull back too rapidly on the syringe plunger too fast, as the vein may collapse. (D249.w10)
  • If necessary, rotate the needle within the vein to improve blood flow.
  • If necessary, move the needle slightly within the vein from time to time. (D249.w10)
  • One the Vacutainer or syringe is full, if more blood is required, detach it from the needle and attach another Vacutainer/syringe. Take care to stabilise the needle in the vein and not to push it through the far side of the vein when attaching a new vacutainer/syringe.
  • Once you have finished, stop pressing on the vein at the base of the tongue, withdraw the needle, and rub the puncture site for 30 seconds with your finger tips (D249.w10); place pressure over the puncture site for about 30 seconds. (V.w5)
  • Dispose of the dirty needle and/or syringe in an appropriate Sharps box. (D249.w10)
  • For Vacutainer tubes with anticoagulants/preservatives, make sure the tube is at least half full and invert several times to ensure mixing. (D249.w10)

(D249.w10)

From a leg vein
  • Put pressure on the vein with your finger proximal to the intended sampling site to make it distend (V.w6) OR tie a surgical tube (rubber tubing) around the upper part of the leg, just tight enough to distend the vein. (D249.w10)
  • Feel the position of the distended vein.
    • The femoral vein can also be located by first palpating the femoral artery, which is alongside the vein. (J40.35.w1)
  • Trim the hair in a 5 cm by 5 cm area over this where you intend to take the blood sample.
    • Clipping the hair over the vein makes venipuncture much easier. (V.w6)
  • Swab the skin over the vein with sterile solution.
  • Carefully insert the needle, bevel upwards, into the vein at a 10-20 degree angle, with the needle pointing towards the bear's body.
    • If using finger pressure to raise the vein, take care that the needle does not get close to your finger and risk a needle-stick injury.(V.w5)
  • If using a vacutainer, keep the vacutainer holder firmly in place using the little and ring fingers of the hand pressing on the vein, then use the thumb of the other hand to push the vacutainer tube firmly onto the needle.
  • If using a syringe, draw back on the plunger; be careful not to pull back too rapidly on the syringe plunger, as the vein may collapse. (D249.w10)
  • If necessary, rotate the needle within the vein to improve blood flow.
  • If necessary, move the needle slightly within the vein from time to time. (D249.w10)
  • One the Vacutainer or syringe is full, if more blood is required, detach it from the needle and attach another Vacutainer/syringe. Take care to stabilise the needle in the vein and not to push it through the far side of the vein when attaching a new vacutainer/syringe.
  • Once you have finished, stop pressing on the vein/release the tubing, withdraw the needle, and rub the puncture site for 30 seconds with your finger tips (D249.w10); place pressure over the puncture site, holding a piece of cotton wool against it. (V.w5)
  • Dispose of the dirty needle and/or syringe in an appropriate Sharps box. (D249.w10)
  • Transfer blood from a syringe to the blood tubes immediately. To transfer blood from the syringe to appropriate blood tubes, make sure the needle is NOT on the syringe, then depress the plunger. Fill the tubes to the level indicated and cap them. For tubes containing anticoagulant/preservative, immediately invert the tubes several times to ensure proper mixing. 

(D249.w10)

From the jugular vein
  • Put pressure on the jugular vein near the base of the neck with your thumb to make it distend. (V.w5)
  • Feel the position of the distended vein and trim hair in a 5 cm by 5 cm area over this.
    • Clipping the hair over the vein makes venipuncture much easier. (V.w6)
  • Swab the skin over the vein with sterile solution.
  • Carefully insert the needle, bevel upwards, into the vein at a 10-20 degree angle, with the needle pointing towards the bear's head (away from where you are holding the vein - this removes any risk of a needle-stick injury). (V.w5)
  • If using a Vacutainer, keep the vacutainer holder firmly in place using the little and ring fingers of the hand pressing on the vein, then use the thumb of the other hand to push the vacutainer tube firmly onto the needle.
  • If using a syringe, draw back on the plunger, taking care not to pull too fast and collapse the vein.
  • If necessary, rotate the needle within the vein to improve blood flow.
  • One the Vacutainer or syringe is full, if more blood is required, detach it from the needle and attach another Vacutainer/syringe. Take care to stabilise the needle in the vein and not to push it through the far side of the vein when attaching a new vacutainer/syringe.
  • Once you have finished, stop pressing on the vein/release the tubing, withdraw the needle, and rub the puncture site for 30 seconds with your finger tips (D249.w10); place pressure over the puncture site with your fingers (J40.35.w1, V.w5).

(D249.w10)

Appropriate Use (?)
  • The veins on the underside of the tongue have the advantage of being easily visible, and it is easy to see the needle through the wall of the vein. Additionally, saliva will assist rapid healing of the puncture site. (D249.w10)
Notes
  • It may be easier to take blood directly into an evacuated blood collection tube rather than using a needle and syringe. (D249.w10)
Complications/ Limitations / Risk
  • In Ursus maritimus - Polar bear, the jugulars and the veins of the front legs are hidden by fat. (J40.32.w1)
  • The skin over the jugular is thick. (V.w6)
  • The femoral vein is quite deep. (V.w6)
  • It is important to put pressure over the vein, particularly large veins such as the femoral and jugular, after taking the blood sample, to ensure that bleeding stops. (V.w6)
Equipment / Chemicals required and Suppliers
  • Vacutainer or other evacuated blood collection equipment (tubes, needles and needle holder). (D249.w10)

  • Or needle and syringe. (D249.w10)

  • A 21 G needle is suggested for blood sampling Ursus americanus - American black bear from the femoral vein. (J1.39.w2

  • Appropriate material for a tourniquet for raising the vein on a leg, if required, e.g. surgical tubing. (D249.w10)

Expertise level / Ease of Use This procedure should only be carried out by an individual with appropriate clinical training and practical experience.
Cost/ Availability
  • Inexpensive.
  • Vacutainer or other evacuated blood collection equipment may not always be readily available.
Legal and Ethical Considerations
  • Latex gloves should be worn during venipuncture to reduce any risk of infection. (D249.w10)
  • Dirty needles and syringes must be disposed of properly (needles always into a properly marked sharps container. (D249.w10)
  • In some countries there may be legislation restricting the use of this type of technique to licensed veterinarians. For example in the UK: "The Veterinary Surgeons Act 1966 (Section 19) provides, subject to a number of exceptions, that only registered members of the Royal College of Veterinary Surgeons may practice veterinary surgery." (see: LCofC1 - RCVS Guide to Professional Conduct 2000 - Treatment of Animals by Non-Veterinary Surgeons).).
Author Debra Bourne MA VetMB PhD MRCVS (V.w5)
Referee Suzanne I. Boardman BVMS MRCVS (V.w6)
References B10.48.w43, B16.9.w9, B123.19.w19, B336.51.w51, B379.19.w19, B407.w18, D249.w10, D255.6.w6e, J1.21.w8, J1.39.w2, J30.50.w1, J40.41.w1, P62.9.w1, V.w6

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