Chronic implants, such as chronic intravenous catheters and head caps, present a high risk for post-surgical infection. Therefore, post-surgical maintenance of these implants must be performed on a routine basis. If infection develops in the area of the implant, removal of the implant may be required as determined in consultation with a DLAM veterinarian.
Note: Many different catheters are in use, and manufacturer's instructions should be followed if they differ from the general recommendations below.
Prior to compound administration or sampling, injection ports and caps should be cleaned with 70% isopropyl alcohol and then allowed to dry before needle puncture. The ports and caps should be changed if they appear damaged.
The area surrounding the catheter exteriorization site must be monitored daily for signs of infection. If signs of potential infection are seen (swelling, redness, or discharge), a DLAM veterinarian should be consulted. The skin surrounding the exteriorization site should be cleansed with isopropyl alcohol and then povidone iodine or Chlorhexidine solution once weekly. However, the catheter itself and the exit wound should not be disturbed during this procedure. Ointments are not recommended as they may damage some catheters.
Injection of only sterile solutions into the catheter is a critical requirement (for additional information, please refer to the ARC Policy on Use of Pharmaceutical-Grade Compounds). Solutions should be freshly prepared or stored under refrigeration if prepared in advance. The top or mouth of the vial containing solutions for injection must be kept clean and wiped with alcohol before the solution is drawn. Sterile saline sufficient to flush the catheter lumen should be injected after the study medication. Some catheters (those not equipped with valves) may be less likely to clot if they are filled with a diluted heparin solution (1000U/500 ml saline) after the saline flush. This heparin solution should be withdrawn from the catheter before any subsequent injections are made.
Routine maintenance of the skin area surrounding the head cap is vital to minimizing infection, as this area represents a non-healing wound. While Chlorhexidine® and Betadine® are acceptable skin disinfectants, Chlorhexidine is preferable for cleaning skin edges that are adjacent to the head cap because it does not break down in the presence of organic matter and has a longer duration of activity than does Betadine®. Cleaning of the head cap margin should occur at an appropriate frequency as determined through consultation with a DLAM veterinarian. An increase in discharge or extreme crustiness of the area may indicate that an infection is present, and a DLAM veterinarian should be consulted. The routine use of triple antibiotic ointment on the skin edge is discouraged as it promotes antibiotic resistance and may promote growth of Chlamydial organisms. Other maintenance procedures may be necessary depending upon the type of head cap or study duration.
Cephalic Recording Wells
Cephalic recording wells should be flushed regularly with sterile pharmaceutical-grade saline. Wells must be monitored for signs of bacterial and fungal infection, including presence of an increased amount of fluid, cloudiness, blood, or exudate. A DLAM veterinarian should be consulted for examination of any of these conditions so that appropriate treatment may be initiated. Recording electrodes must not be passed through wells that are suspected of being infected.
Frequency of Cleaning of Head Caps and Recording Wells in USDA-Regulated Species
For USDA-regulated animals, recording cylinders must be cleaned after each use; when animals are not actively under study, wells must be cleaned three times per week. Head caps should be cleaned at least once per week, or more often if indicated following consultation with the veterinarian. Investigators must maintain records of head cap and cylinder maintenance.
Approved 10/27/03; Revised 8/24/09