Main venous access routes
Intravenous transfusion is considered the primary and most reliable route for administering transfusion media. Depending on the clinical situation, the patient's anatomical features, and treatment goals, surgeons choose one of three access routes. The most frequent and routine method is puncture of the cubital vein (antecubital vein). If superficial veins are inaccessible or long-term therapy is planned, subclavian vein puncture is used. The third, rarer, but critically important method is phlebotomy, which involves surgical dissection to isolate the vessel.
Technique of cubital vein puncture
The procedure begins by applying a rubber tourniquet to the lower third of the patient's arm. The most important criterion for proper application: only the veins must be compressed, while arteries remain patent (pulse is preserved). When the patient clenches their fist, the veins should stand out clearly beneath the skin. The surgical field is treated with alcohol or an alcohol-iodine solution, then isolated with sterile drapes.
The puncture is traditionally performed with a Dufoir needle, held by the hub or attached to a syringe. First, the skin and subcutaneous adipose tissue are punctured, the needle is advanced about 1 cm above the vein, and then the anterior wall of the vein is punctured and the needle is advanced along the vessel. A sure sign of success is the appearance of a stream of blood from the hub.
Step-by-step procedure after the puncture:
- Collection of 3–5 ml of blood for control blood typing and compatibility tests.
- Removal of the tourniquet.
- Connecting the infusion set with an isotonic NaCl solution (to prevent needle thrombosis).
- Securing the needle to the skin with regular adhesive tape.
- Performing rapid diagnostics (AB0, Rh factor, compatibility tests).
- Direct connection of the blood transfusion set.
Phlebotomy: indications and surgical procedure
Phlebotomy is indicated when puncture of superficial veins is impossible. Most often, this occurs when veins collapse due to severe shock or because of marked obesity in the patient.
The execution technique includes the following steps:
- Preparation of the surgical field and isolation with sterile drapes.
- Local anesthesia: tissues at the incision site are infiltrated with a 0.25% novocaine solution.
- Application of a tourniquet (strictly without compressing arteries).
- Incision of the skin and subcutaneous tissue, careful isolation of the vein with surgical forceps.
- Placing two ligatures under the vessel. The peripheral ligature serves as a "stay suture" for ease of manipulation.
- Opening the vessel lumen (needle puncture or microscalpel/scissors snip).
- Insertion of the catheter or needle followed by secure fixation with the central ligature.
- Connecting the transfusion set and placing 2–3 sutures on the skin wound.
Procedure completion and long-term therapy
Proper completion of the transfusion requires compliance with safety protocols. Blood is never transfused entirely: about 20 ml of blood must be left in the set. The tubing is clamped and disconnected, and the needle is withdrawn from the vein. The puncture or phlebotomy site is wiped with an alcohol-iodine solution, and a pressure bandage is applied to prevent hematoma.
If prolonged infusion therapy (transfusion of solutions and blood over several days) is required, permanent venous access is established. For this, puncture of the subclavian or external jugular vein is performed with the insertion of a special catheter. Such a catheter can remain in the vein for up to 1 month, and transfusion sets can be easily connected to it as needed.
Briefly: answers to topical questions
What complications can occur during puncture and catheterization of the subclavian vein?
Puncture and catheterization of the subclavian vein may lead to the following complications:
- Venous air embolism (VAE); risk factors include low circulating blood volume combined with low central venous pressure, as well as catheter removal while not in the supine position.
- Pneumothorax — possible if the pleural dome, which projects above the clavicle into the neck region, is injured.
- Minor hemothorax — possible if the puncture point is too low.
What specific individual compatibility tests are performed immediately before connecting the blood transfusion set?
Before connecting the blood transfusion set, the following are performed:
- Group compatibility test — determination of compatibility according to the AB0 system.
- Rh compatibility test — checking compatibility according to the Rh factor.
In emergency transfusions, AB0 and Rh compatibility tests are performed using blood from each container. The biological test is performed at the very beginning of the transfusion.
What surgical instruments are necessary to perform a phlebotomy?
The following instruments and devices are required to perform a phlebotomy:
- Forceps — used to isolate the vein after incision of the skin and subcutaneous adipose tissue.
- Scissors — used to snip the vein wall when opening its lumen.
- Needle or catheter — inserted into the vessel lumen and secured with the central ligature.
- Two ligatures: the peripheral one serves as a stay suture, while the central one secures the needle or catheter.
After the procedure, 2–3 sutures are applied to the skin wound.
Criterion for a proper tourniquet: "The vein is engorged, and the pulse is beating." If there is no pulse on the artery, the tourniquet is overtightened.
Class and exam questions
In which cases do surgeons resort to phlebotomy?
Phlebotomy is used when it is impossible to puncture superficial veins. Most often, this occurs due to vein collapse in a shock state or in marked obesity.
Which veins are used for multi-day infusion therapy?
To ensure long-term access, the subclavian or external jugular vein is usually punctured with the placement of a catheter that can remain in place for up to a month.
How to make sure that the Dufour needle has entered the vein precisely?
The primary and most reliable sign of a successful puncture is the appearance of a stream of blood from the needle hub immediately after piercing the anterior vessel wall.
What else to study on this topic
- Rapid blood typing using the AB0 system
- Determination of Rh factor before transfusion
- Performing individual compatibility tests
- Prevention of needle thrombosis with isotonic solution
- Complications of subclavian vein catheterization
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