Drug Delivery Central Vascular Access Modes

?Drug? Delivery Central Vascular Access Modes

1. INTRODUCTION:

Accessing blood stream through central and peripheral blood vessels is mandatory for delivering chemotherapeutic agents in cancer patients. A vascular access device or a tubing remains mandatory to deliver drugs in cancer patients to avoid unnecessary needle pricks. Central venous access devices (CVAD) provide access to the central venous system via the superior vena cava (SVC) or the inferior vena cava (IVC). A variety of vascular access devices exist to allow short or long term use of catheters for fluid, nutrition or medication infusion.

The choice of vascular access depends on duration of chemotherapy, anatomy of patients, and the ease of accessibility to peripheral veins.

1. There are 3 modes for accessing central venous access.

1. Peripherally Inserted Central Catheter ( PICC):?

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???????????????????????????????????????PICC lines can be used? upto 1 year. PICC lines are inserted above? the antecubital line. Here a flexible,thin catheter is inserted into a large vein via peripheral vein, could be arm or leg vein. It is extremely beneficial in the pediatric population. TPN and chemotherapeutic agents have a potential to cause irritation, in such cases central venous lines are more preferable than PICC lines.

2. Central Venous Lines (CVL):

????????????????????????????????????????A catheter is tunneled into one of the large veins, could be Internal jugular vein, subclavian vein or femoral vein and then they are secured into superior or inferior vena cava. Nowadays, for prevention of infection, central lines are now available with antimicrobial coated catheters. Various sizes are available depending on the age of the patient. The evolution of ultrasonography and its importance in CVL insertion has decreased the chances of infection and failure rate.

3. Implantable Venous Access Devices (IVAD) or (Port) devices:

?????????????????????????????????????????????????????IVAD which we commonly call it to be chemoport devices in our routine practices is an implantable device called port- a - cath. Port is placed just under the skin which is noticed as a small bump over the chest area. Port is made from a silicon bubble and for accessing it requires a special needle which is inserted from skin into the rubber reservoir. IVAD looks more cosmetically superior than CVL and PICC lines. If good aseptic precautions are taken, the port can be used even for more than 1 year. There are two types of needles. Non coring needles are mostly preferred. They don't cause holes on entering or exiting the skin. Depending on the type of treatment non coring needles can be kept in place for a week.

??????????c) ? Complications noticed with Vascular Access Devices:

????????????????????????????????????????The failure and complications of CVAD result in interrupted medical treatment , morbidity and mortality of patients. CVAD failure is defined as CVAD loss of function before completion of necessary treatment. CVAD complications were defined as CVAD associated with bloodstream infection, thrombosis, dislodgement, occlusion and breakage.?

1. Twiddler's syndrome:?

????????????????????????????????This syndrome? occurs due to intentional or unintentional manipulation of superficial vascular devices. when suture has been displaced by either trauma or twiddling..This causes displacement of the port and swelling over the port placed area. This requires immediate removal of the port.

2. Infection:

????????????????????????????Infections are the most prevalent CVAD complication. To prevent these complications, skilled clinician who adheres to infection prevention protocols are more preferred. Some important preventive steps to avoid infection include good hand hygiene, skin antisepsis with 0.5% chlorhexidine in alcohol solution, sterile barrier precautions and avoid femoral vein cannulation.

3. Malposition:?

???????????????????????????Malposition is defined when catheter tip is dislocated or not located at aortocaval location or vena cava location.Malposition could be primary or secondary malposition. Primary malposition occurs during the time of insertion. Secondary malposition occurs during any time during the catheter dwell time which we commonly term as tip displacement.

4. Nerve Injury:

???????????????????????????It is caused due to inadvertent puncture of nerve structure while insertion. Patients usually complain of unusual pain or discomfort during insertion.

5. Air Embolism:

???????????????????????????It can occur during use and maintenance of CVAD.Air embolism occurs when bolus of air enters the vascular system causing an intracardiac lock at the pulmonary valve. This prevents blood ejecting to the pulmonary vein leading to hypoxemia and cardiac arrest.

6. Bacteremia and Septicemia:?

?????????????????????????????Bacteremia from CVAD? is considered when the same organism is isolated from both CVAD and blood. Most of the CVAD bacteremia are said to be preventable. Preventive measures include good hand hygiene, aseptic technique during administering, disinfecting needleless connectors with alcohol wipes, chlorhexidine or alcohol caps before accessing.Changing administration sets and additional devices are helpful in preventing bacteremia.?

7. Venous Thrombus:

????????????????????CVAD insertion itself accounts for catheter related venous thrombosis. The additional risk factors include previous coagulation abnormalities, age factors, genetic abnormalities, pregnancy and the type of surgery.

8. Phlebitis:?

???????????????????It is caused due to endothelial cell inflammation could be due to mechanical, chemical or bacterial. It is usually accompanied by redness, erythema , streak formation and palpable cord.

CONCLUSION:?

CVAD-associated complications are serious patient safety events that can prolong illness, cause permanent physical damage, increase healthcare costs, extend length of stay, or lead to death. Diligent healthcare assessment and intervention is instrumental at CVAD insertion, care, use, maintenance, and discontinuation to prevent and detect the onset of CVAD-associated complications and to initiate corrective action and therapeutic management when complications occur.