The mechanism of IV (intravenous) injection involves inserting a hollow needle through the skin directly into a vein to deliver medication or fluids directly into the bloodstream.
Here's a breakdown of the process:
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Preparation: The skin at the injection site is cleaned with an antiseptic solution (e.g., alcohol swab) to minimize the risk of infection. A tourniquet may be applied proximal to the injection site to distend the vein, making it easier to visualize and access.
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Needle Insertion: A needle, typically attached to a syringe containing the medication or fluid, is inserted through the skin and into the targeted vein. The needle is usually inserted at a shallow angle (around 15-30 degrees) to avoid passing completely through the vein.
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Verification of Placement: Once the needle is believed to be within the vein, the healthcare provider may gently pull back on the syringe plunger. If blood enters the syringe, this confirms that the needle is correctly positioned inside the vein.
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Injection: Once correct placement is confirmed, the tourniquet is released. The medication or fluid is then slowly injected into the vein. The rate of injection depends on the medication and the patient's condition.
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Needle Removal and Aftercare: After the injection, the needle is carefully withdrawn from the vein. A sterile gauze pad is immediately applied to the injection site, and pressure is held to prevent bleeding and bruising. A bandage may be applied to keep the gauze in place.
Key Considerations:
- Sterility: Maintaining a sterile technique is crucial to prevent infections.
- Vein Selection: Selecting an appropriate vein is important for successful insertion and minimizing discomfort. Common sites include veins in the arm (e.g., cephalic, basilic, median cubital veins) and hand.
- Patient Comfort: Healthcare providers aim to minimize discomfort during the procedure.
Types of IV Access:
- Bolus Injection: A single, relatively large dose of medication is administered quickly. This is the method described above.
- Intermittent Infusion: Medication is administered over a longer period (e.g., 30 minutes to an hour) via a secondary IV line connected to a primary IV fluid bag.
- Continuous Infusion: A constant flow of fluids or medication is administered over an extended period. This requires a continuous IV line and infusion pump.
