June 29, 2022

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Improved TAT skin test solution suction process to prevent foam

Improved TAT skin test solution suction process to prevent foam


Improved TAT skin test solution suction process to prevent foam.  The positive rate of the modified method is significantly lower than that of the traditional method, and the liquid can be shaken evenly without flicking the bubbles in the syringe.

Improved TAT skin test solution suction process to prevent foam

 

Tetanus Antitoxin (TAT) is a biological product made by the ammonium sulfate salting-out method. It is a high molecular compound solution of surface active substances. It is easy to produce foam during suction. In addition, there is air in the dead space during suction. , Mixed with TAT to produce foam, which affects the accuracy of the skin test solution concentration, resulting in false positives in the skin test. According to the literature, the false positive rate of TAT is 61.7%-75.8%, and the skin test solution with too high concentration is more likely to cause foam. increase.

Preparation method of skin test solution

Take each 1 mL TAT solution containing 1 500 IU

Traditional method: Use a disposable 1 mL syringe to aspirate 0.1 mL of TAT stock solution, exhaust, and then aspirate 0.9 mL of normal saline. After shaking, perform a skin test. The injection site is the middle of the three transverse fingers on the transverse stripes of the wrist. The needle was inserted parallel to the transverse stripes of the wrist, and 0.1 mL of TAT skin test solution was injected. The results were observed 20 minutes after injection.

Improved method: first draw 0.1 mL of normal saline, then draw 0.1 mL of TAT stock solution, and finally draw 0.8 mL of normal saline. The injection method is the same as the traditional method.

Advantages of the improved method:

According to literature reports, through repeated observations of the dosage of TAT stock solution for many years, if the skin test solution is prepared according to the textbook method, the concentration of TAT skin test solution will be too high and the false positive rate will increase. Zhou Guiping believes that the dose and concentration of TAT skin test solution are directly proportional to the degree of local reaction.

The higher the concentration, the stronger the local reaction. The excessively high concentration also causes the increase of foam, and the dead space problem seriously affects the accuracy of drug dosage. , The traditional method is greatly affected by the dead space, resulting in high skin test solution concentration.

The positive rate of the modified method is significantly lower than that of the traditional method. First draw 0.1 mL of normal saline, and then draw 0.1 mL of TAT stock solution, which will accelerate the dilution and dissolution without foaming, and finally draw 0.8 mL of normal saline. Due to the suction of the syringe, There is a certain impulse when 0.8 mL of normal saline enters the syringe. At this time, the impulse in the lumen is the largest, which has a shaking effect on the TAT in the lumen, so there is no need to flick the air bubbles in the syringe by hand to achieve the uniform liquid The role of.

 

(source:internet, reference only)


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