How do I clean, disinfect and prepare a Kaha rat telemeter for reuse?

With proper care, Kaha Rat Telemeters are designed to be reused multiple times.  However, after implantation for a long periods of time, connective tissue can form around the catheter, lead wires, and telemeter body. When detaching the telemeter body from the muscle and this connective tissue during telemeter removal, take great care to only cut the sutures holding the telemeter in place; extreme care should also be taken not to damage the pressure catheter body and sensor tip.  The telemeter should be placed in a beaker or dish filled with fresh saline or distilled water immediately after removal and soaked until ready to be cleaned, DO NOT allow the telemeter to dry.

Cleaning

  1. Remove the telemeter from the saline or distilled water it has been soaking in, and place it in one of the recommended enzymatic cleaning solutions listed below, which are widely available from most hospital supply companies:  Enzymatic cleaning is essential to remove blood, serum proteins, and tissue debris from the surface of the telemeter, and prevent protein build-up on the pressure sensor. If not removed, this protein build-up will cause pressure signal drift during subsequent implantations.  Please note, any cleaning product that contains a surfactant CANNOT be used with any pressure telemeter.
  2. After soaking for the recommended time and temperature in the enzymatic cleaner, gently wipe the telemeter's pressure sensing tip with a soft cotton gauze pad or swab stick to remove any remaining film or deposits.  The process is best accomplish while viewing the sensing tip under a microscope. As always, care must be taken to not damage the sensing tip.
  3. After soaking and wiping, thoroughly rinse the telemeter with fresh distilled water or saline.
  4. After rinsing is complete, gently dry the catheter as follows:
    1. Fold a soft tissue or Kimwipe®
    2. Use gentle stroking to dry the catheter tip.
    3. Do not pull the catheter tip through a folded tissue.
    4. Do not allow the catheter to air dry on a tray, table, or countertop.
  5.  After the cleaning and drying procedure is finished:
    1. Protect the sensor area on the catheter tip by carefully placing it in the foam that came with the telemeter.
    2. Return the telemeter to its original plastic tray.
    3. Slide the tray inside the box and store the telemeter in a cool, dry place until the next use. 

IMPORTANT: Delays in rinsing a telemeter after removal will reduce cleaning effectiveness! Re-examine the pressure sensor active surface (diaphragm) to ensure no blood or materials remain after cleaning.  A dirty sensor may cause baseline drift when reimplanted. 

If checking the offset/calibration of the telemeter after cleaning, the following telemeter conditions must be met prior to recording values:

  • Hydrated for a minimum of 48 hours
  • Turned on for 4 hours
  • Soaked in 38°C isotonic saline for a minimum of 30 minutes 
  • Held at 38°C in this same saline bath as above with the sensor tip no more than 5 mm under the saline
  • In the dark

Sterilization

Preventing infection is key for collecting quality recordings of normal physiology and post-surgery animal survival.  All telemeters are sterilized prior to shipment using Ethylene Oxide Gas Sterilization, and can be implanted without further sterilizing as long as the sterile pouch is intact.  If this initial sterilization is compromised or to prepare a telemeter for reuse, use one of the methods below to sterilize your telemeter.

IMPORTANT: 

  • Under no circumstances should the telemeter be autoclaved or subjected to temperatures over 60°C as this will damage the telemeter.
  • Do not use alcohol as a sterilizing agent.  This will damage the telemeter.
  • Do not sterilize by radiation (gamma or e-beam), plasma, peroxide or formaldehyde vapor solutions.
  • Carbon paste electrodes like those used with Kaha Rat Tissue Oxygen Telemeters should not be sterilized. Please see the ADInstruments Kaha Support Page for alternate recommendations.

Disinfection/Sterilization

  1. The telemeter must be cleaned, rinsed and dried before disinfection or sterilization as soil, debris, proteins, and water can interfere with the effectiveness of the disinfection/sterilization procedure.  Note that some disinfectants have a limited usable life after activation or opening the container, failure to take notice of the warnings can inhibit the effectiveness of the disinfection process.
  2. Prepare the disinfectant according to the manufacturer’s instructions.
  3. Soak the telemeter in the disinfectant at the temperature and time intervals listed.
  4. Rinse the telemeter well in sterile pyrogen-free water (or sterile saline) before implantation.  A minimum of three separate rinses is recommended.  Do not reuse any of the water used for rinsing since it will be contaminated with the disinfectant.

IMPORTANT: Use only the listed recommended cleaners and disinfectants for the times/temperatures indicated. 

Chemical Sterilants

Chemical sterilants are considered cold sterilants and should be used for the sterilization of heat sensitive medical equipment such as Kaha telemeters.  When used properly, chemical sterilants will destroy all viable forms of microbial life.  WARNING: Some examples of chemicals that will cause damage to telemeters include, but are not limited to: alcohols, phenols, iodophors, and hypochlorite.  The approved Chemical sterilant products are listed below. 

Products with similar names are available but may not be suitable, so please confirm with ADInstruments support staff before using any product other than those listed.  Also, any sterilization product that contains a surfactant (e.g. Cidex 7, Cidex Plus 28 Day, or Metrocide 28) CANNOT be used with any pressure telemeter.

Rinse with Sterile Saline 

The telemeter should always be washed in sterile saline before implantation to remove all traces of the sterilant.  Fresh Sterile saline can also be used to temporarily store (< 24 hours) the telemeter aseptically until surgical implantation.

Ethylene Oxide Gas Sterilization

These sterilizers operate at a low temperature of 55°C and use chemicals as the sterilant.  Items are packed and dry at the end of the sterilizing cycle.  Telemeters are suitable for Ethylene Oxide Gas Sterilization as long as they are not subjected to temperatures above 60°C. 

 

For further technical assistance with this or any other issue, please contact ADInstruments Technical Support by clicking HERE.