Steps

Rationale/Points of Emphasis 1

1 Review the child’s medical record to determine the rationale and the timing for the procedure.

For the child with diabetes, it is important to perform the technique at the prescribed time for the assessment of insulin requirements and treatment of hypoglycemia. Strict glycemic control is important to prevent diabetes-related complications. For other children in whom hypoglycemia or hyperglycemia is a concern, the procedure is performed based on clinical signs and symptoms (see Chart 20-1 ).

2 Gather the necessary supplies.

Promotes efficient time management and provides an organized approach to the procedure.

3a Ensure test strips are in a tightly sealed container. Make sure the cap is always kept on the vial of strips. Observe the strip for discoloration.

Prolonged exposure of test strips to air may lead to inaccurate test results. Strips are sensitive to light and humidity and may become inactivated.

3b Check expiration date on strips. Perform necessary quality control on equipment per manufacturer’s instructions, or verify that quality control has been done, and ensure that all equipment is functioning correctly.

Properly functioning equipment and supplies are needed for accurate results.

caREminder

Reagent containers that have been left open or strips that are discolored should be discarded.

4 Load lancet in lancet device according to manufacturer’s instructions.

Lancet device will be more comfortable for the child because it may not penetrate the skin as deeply as using the lancet alone.

KidKare For the child’s comfort, use a lancet device and lancet designed for pediatric blood glucose monitoring. Lancet sizes vary for use with neonates, children, and adults. Many lancet devices can be adjusted for depth of penetration.

caREminder

Use a new lancet for each procedure.

5 Perform hand hygiene, and don gloves. Use standard precautions throughout the procedure.

Reduces transmission of microorganisms. Protects against exposure to blood or body fluids.

6a Select a puncture site (Figure 20-1); refer to Chapter 17 .

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  In neonates, infants, and children who are not walking, the outer aspect of the heel is commonly used.

  
  
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  In infants and toddlers with diabetes, the toe pads can be used.

  
  
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  In a child or adult, the end or lateral aspect of the fingertip is the most common site. Check specific meter for approved alternate sites for testing (e.g., finger pads, heel of hand on thumb side and finger side, forearm, upper arm, thigh, calf, or abdomen).

Do not use the very center of the finger pad. Fingertips have an abundance of cutaneous blood vessels; however, they are densely innervated and consequently painful. Because the center of the finger pad is very sensitive, using a site just lateral to this can help reduce the child’s discomfort.

Toes are acceptable since decreased sensation to this area has not occurred yet because these children do not have long-standing disease.

Figure 20-1 Puncture sites for capillary blood specimen collection for glucose monitoring.

6b “Alternate site testing” (e.g., testing on heel of hand on thumb side and finger side, forearms, upper arms, thighs, calf, abdomen) is another option; refer to meter’s manufacturer’s instructions. When alternate sites are used, the area must be rubbed vigorously.

Alternate sites have fewer nerve endings than fingers and thus are an option for children who complain of a lot of pain with finger sticks. Alternate sites are often desirable for adolescents, who can be very sensitive about the visibility of multiple finger punctures (Figure 20-2). Vigorous rubbing helps increase circulation.

Alternate site testing is not as accurate as testing fingertips, heels, and toes when measuring hypoglycemia because the rate of blood flow to digits is faster than to alternate sites and the dermis does not have the vascularity that digits do; therefore, when glucose is changing rapidly, the digits are more accurate than alternate sites that lag behind. Alternate site testing is not recommended for people with hypoglycemia unawareness or those unable to verbalize symptoms of hypoglycemia. Discrepancies in blood glucose between fingertip and forearm during rapid changes in blood glucose have been reported, although these discrepancies may be due to patients not accurately following the manufacturer’s instructions on the use of the measurement instrument.

Figure 20-2 “Alternate site testing” (AST) or “off-site” testing locations can be used to obtain blood glucose sampling using several new devices available on the market.

7 Wash the site to be used for testing with soap and warm water or clean with an alcohol wipe. If an alternative site is used, after cleansing, place a warm, wet cloth on the site for 1 minute. A heel-warming device can be used when testing on the foot. Allow testing site to dry completely before puncturing.

Monitor the temperature of the warming device to avoid burns.

Ensure site is dry before the skin is pricked. Alcohol and soaps interfere with reagents on strips, giving an inaccurate reading. Fluid (water, alcohol) also dilutes the specimen, giving a false low reading.

Application of heat for 1 minute has been shown to promote vasodilation, which assists in obtaining an adequate-sized sample. Residual alcohol or water can dilute the sample.

8 Place test strip into meter per manufacturer’s instructions.

Prepares for testing.

9 Calibrate the meter by matching the code on the meter to the code on the test strip container according to manufacturer’s instructions.

Matching codes ensures the reading is accurate.

10 Hold the child securely and place the puncture site in the appropriate position (e.g., place extremity in a dependent position).

Placing extremity in a dependent position facilitates blood flow to the area.

KidKare If the child is anxious, place your nondominant hand against his or her body while performing the procedure so that the child will not be able to pull away as the lancet device is deployed. An infant may be swaddled, leaving the chosen extremity uncovered for access.

11a Hold lancet perpendicular to the skin and puncture site using the lancet device.

Allows for adequate skin penetration.

11b Continue to position the site below the child’s heart.

Positioning the site below the heart allows gravity to help increase blood flow and obtain adequate-sized sample.

12 Ensure that an adequate-sized drop of blood is obtained before applying it to the test strip/meter.

Avoid squeezing the site excessively, because excessive squeezing can contaminate the sample with tissue fluid and cause hemolysis of sample and trauma to the site.

Facilitates accurate test results. Too little blood may give a false low reading, may not start the test, or may give an error code, depending on the meter. Volume size required by the meter may range from 0.3 to 30 µL.

13 Apply first drop of blood to the test strip.

All material manufacturers currently recommend using the first drop of blood. Check meter manual for verification; each meter is different. A “hanging drop” may be needed, and the finger may not touch the test pad. The meters have hematocrit and ambient temperature restrictions as well as substances in the bloodstream that may interfere with an accurate reading. In a child in shock or with severe dehydration, there may be a false “low” result. The accuracy of results is dependent on proper technique. Clinical decision making is based on blood glucose result.

Follow the manufacturer’s instructions completely when performing the test.

14 Apply cotton ball or gauze to puncture site and apply pressure. Apply bandage if needed.

Minimizes bleeding at site.

If the child has a clotting problem, you may need to apply pressure for a longer time.

15 Follow the manufacturer’s directions regarding the developing time and method for reading and interpreting the results.

Proper developing time and use of the equipment are critical to achieving accurate test results. Ensures accuracy when making treatment decisions.

caREminder

A reading from a blood glucose meter is not as accurate as a laboratory result and does not distinguish between true hypoglycemia and a low-normal reading. The diagnosis of diabetes or verification of hypoglycemia must be made using laboratory blood glucose results, not meter results. Venous and capillary blood glucose concentrations may differ, depending on how long after a meal the sample is collected. Plasma and serum readings may be 10% higher than whole blood.

16 To obtain a visual reading using glucose test strips, follow steps above to obtain blood drop and drop onto test strip; find a good light source and compare the test and pad colors to the color scale on the bottle label from which the test strip was drawn.

Each bottle has a color chart that corresponds to the reaction characteristics of the test strips within that vial.

caREminder

To obtain an accurate value, follow the manufacturer’s instructions for appropriate timing of steps.

17a Dispose of used lancet and other waste in appropriate receptacles.

Standard precautions.

17b If required, turn off meter and return to appropriate storage area.

Makes meter available for future testing.

18 Remove gloves and perform hand hygiene.

Reduces transmission of microorganisms.