Which finger should not be used for dermal puncture because of increased risk of bone puncture?
The distal end of the third or fourth finger is the most commonly used site. The very tip of the finger should not be punctured because there is a greater chance of puncturing bone as the bone is close to the skin surface.
Why should a skin puncture not be performed on the index finger?
The thumb (1) is to be avoided because it has a pulse. The index finger (2) tends to be more calloused, which would make collection of the specimen more difficult. This area is also more sensitive for the patient.
What finger do you use for finger stick?
Best locations for a finger stick is the 3rd and 4th fingers of the non-dominant hand. Avoid the 2nd and 5th fingers if possible. Perform the stick off to side of the center of the finger. NEVER use the tip or center of the finger.
Why is ring finger preferred for capillary?
The middle or ring finger is preferred as having the greatest depth of tissue beneath the skin and hence offering the least chances of injury.
When performing a capillary puncture the finger should not be squeezed to avoid?
Avoid squeezing the finger or heel too tightly because this dilutes the specimen with tissue fluid (plasma) and increases the probability of haemolysis (60).
When are dermal punctures not appropriate?
Dermal punctures should not be performed on previously punctured sites or swollen sites. Excess tissue fluid may contaminate the specimen. If the patient is dehydrated or has poor circulation, it may be impossible to get a quality specimen.
What are disadvantages of skin puncture?
Fainting or feeling lightheaded. Infection (a slight risk any time the skin is broken) Scarring (occurs when there have been multiple punctures in the same area) Calcified nodules (sometimes occurs in infants, but usually disappear by 30 months of age)
When is a skin puncture appropriate?
Skin puncture is especially applicable for severely burned patients, extremely obese patients, patients with thrombotic tendencies, geriatric patients, patients in whom superficial veins are either not accessible or are very fragile, and point of care testing.
Which fingers are used for capillary puncture?
The puncture must be on the palm-up surface of the distal segment (fingertip) of the middle or ring finger (a). The puncture should be made across the fingerprint, not parallel to it (b). The puncture must be performed on the side of the fingertip where tissue depth is sufficient to prevent bone injury.
Which fingers should be used for dermal puncture to obtain capillary blood specimens?
The primary sites used to obtain a capillary specimen are the middle and ring fingers. The thumb is not used because it is often more calloused and has a pulse. The index finger is often very calloused and may cause more discomfort for the patient.
When performing a capillary puncture what areas should be avoided?
The posterior heel and toe should be avoided as puncture sites because the distance between the skin surface and the bone in each case is only 2.33 or 2.19 mm, respectively, which means greater risk of bone damage (3, 13).
What should not be used as a venipuncture site?
VENIPUNCTURE SITE SELECTION: Certain areas are to be avoided when choosing a site: Extensive scars from burns and surgery – it is difficult to puncture the scar tissue and obtain a specimen. The upper extremity on the side of a previous mastectomy – test results may be affected because of lymphedema.