Monday, October 15, 2012

Huber Needles and Implanted Ports

 A Huber Needle is a specially designed hollow needle used with implanted ports. A Huber needle has a long, beveled tip that is inserted through the patients skin as well until it accesses the silicone septum the implanted port's reservoir. The beveled tip of a Huber needle will not remove a core of silicone from implanted port as this is the way it is designed.  This design will allow as much as 2000 needle sticks into the implanted port’s reservoir without having to be changed. Dr. Ralph L. Huber, a dentist, designed the sharp, beveled, directional needle tip and Dr. Edward B. Tuohy, an anesthesiologist, refined it for use in spinal catheters.
Huber needles are used to access ports implanted under the skin of patients who may be suffering from a chronic illness, such as cancer, pancreatitis, or has the need for repeated access to veins for blood withdrawal.  These patients often need the implanted port for infusion of medication, nutritional solutions, blood products, and other various types of treatment.  However, these implanted ports must be accessed and thus comes into play the Huber needle. These needles should be designed to penetrate the port without cutting and dislodging any silicone cores from the ports into which they are inserted.
There are several manufactures that design and produce Huber needles. Bard Access has designed and produced the SafeStep© as well as Smith-Medical has designed and produced the Gripper Plus©
 
 
Uses of Implanted Ports
·         To deliver total parenteral nutrition in those unable to take (adequate) food orally for a long periods of time.
 
·         To deliver chemotherapy to cancer patients (Chemotherapy is often toxic, and can damage skin and muscle tissue)
 
·         Provide a method of delivering drugs quickly and efficiently through the entire body via the circulatory system.
 
·         To deliver coagulopathy therapy
 
·         To withdraw blood in patients who require frequent blood tests
 
·         To deliver antibiotics to patients requiring them for a long time or frequently
 
·         Delivering medications to patients with immune disorders.
 
·         For delivering radiopaque contrast agents, which enhance contrast in CT imaging.

 

Types of Implants

There are many different types of implanted ports. The particular type selected is based on the patient's specific medical conditions.
Portals:
  • can be made of plastic, stainless steel, or titanium
  • can be single chamber or dual chamber
  • vary in height
Catheters:
  • can be made of biocompatible, medical-grade polyurethane or silicone
  • can vary in length (cm)
  • can vary in diameter (mm)
ImplantedPorts can be put in the upper chest or arm. The exact positioning itself is variable as it can be inserted to avoid visibility when wearing low cut shirts, and to avoid excess contact due to a backpack or bra strap. The most common placement is on the upper right portion of the chest, with the catheter itself looping through the right subclavian vein down towards the patient's heart. It can also be situated on the muscle that sits on the ribs with the tube coming up towards the heart.

Risks

  1. Infection - a severe bacterial infection can compromise the device, it this occurs it may require surgical removal of the implanted port and can seriously jeopardize the health of the patient.
  2. Thrombosis - formation of a blood clot in the catheter may block the device and thus it may become inoperable.  However, if this occurs the port maybe flushed with saline and or Ateplase and this is performed by a nurse trained in administering this medication.
  3. Mechanical failure - It is possible that part of the system could break; usually the attached catheter may break off or become dislodged from the port’s reservoir.  Many patients are asymptomatic and mechanical failure is discovered because of an inability to flush or withdraw fluids from the port. In those rare instances intervention surgery is required to withdraw the failed vascular access device.
  4. Respiratory Issues - Attempts to gain access to the subclavian vein or jugular vein can injure the lung, possibly leading to a complication known as Pneumothorax.
  5. Arterial Damage - The subclavian artery can be inadvertently punctured as well as the carotid artery; however, this is rare, since attempts to access the nearby jugular vein are increasingly done with ultrasound guidance.