תזונה פראנטרלית: הזנה פראנטרלית מרכזית

Parenteral nutrition (PN) is a medical intervention that delivers essential nutrients—carbohydrates, fats, proteins, vitamins, and minerals—directly into the bloodstream, bypassing the digestive system. It is crucial for patients with severe digestive disorders or conditions preventing normal nutrient absorption, providing complete nutritional support when oral or enteral nutrition orogastric and nasogastric feeding is not feasible.

Central Parenteral Nutrition (CPN) delivers highly concentrated nutrient solutions through large veins like the subclavian or internal jugular vein, supporting long-term nutritional needs. Peripheral Parenteral Nutrition (PPN) delivers lower-osmolarity solutions through smaller arm veins and is reserved for short-term use, as peripheral veins cannot tolerate highly concentrated solutions.

Patient preparation includes informing the patient, gathering supplies, and donning personal protective equipment. The insertion site is cleansed with 2% chlorhexidine, followed by lidocaine gel for local anesthesia. The patient is positioned supine in Trendelenburg position with their head turned away from the venipuncture site to dilate neck and shoulder blood vessels.

A large-bore needle is inserted under the clavicle into the vein, followed by a radiopaque wire over which the catheter is advanced. After needle removal, the catheter is connected to IV tubing and secured with a sterile dressing using aseptic technique. Proper securing prevents dislodgment and maintains line integrity for nutrient delivery.

X-ray imaging confirms accurate catheter tip positioning in the superior vena cava near the heart, ensuring proper nutrient delivery and reducing complications. Correct placement verification is essential before initiating parenteral nutrition infusion, as malpositioned catheters can cause tissue damage or ineffective nutrient administration.

The catheter is secured with injection caps and connected using needleless adapters or Luer lock devices. Daily flushing with saline or heparin maintains patency and prevents clot formation. If blockage occurs, low-dose tissue plasminogen activator (tPA) may dissolve clots; severe cases require catheter replacement to restore function.

Clinicians use full-body sterile drapes, sterile gloves, head cap, gown, and mask to establish a sterile field and reduce central line-associated bloodstream infections (CLABSI). Strict adherence to sterile technique during insertion and maintenance, combined with proper skin preparation using 2% chlorhexidine, significantly decreases infection risk and improves patient outcomes.