Registered Nurses' Association of Ontario

Nursing Best Practice Guidelines

Glossary of Clinical Terms

Additional Precautions: Extra precautions in addition to routine practices that are based on the way organisms are transmitted. These modes include:

  • Contact;
  • Droplet; and
  • Airborne transmission.

Add-ons: These are devices that include stopcocks, extension sets, manifold sets, extension loops, solid cannula caps, injection/access ports, needles or needleless systems and filters.

Antiseptic: A substance that destroys or stops the growth of micro-organisms on living tissue (i.e., skin) (CNO, 2004).


  • Provide access to the vascular system for the purpose of medication administration, and/ or connectivity of administration sets;
  • May be used to cap unused lumen, or as a part of a saline lock; and
  • May be of needle free or needle access design.

(CDC, 2002; INS, 2000; RCN, 2003).

Catheter dislodgement: Movement of the catheter into and out of the insertion site. Causes of catheter dislodgement include inappropriate securement of the catheter, and motion of the extremity, neck or shoulder. Catheter dislodgement may cause occlusion of the catheter and lead to a change in the catheter tip location. Signs and symptoms of catheter dislodgement include changes in the external length of the catheter, clinical signs of local catheter infection and inability to flush or infuse via the catheter (RCN, 2003).

Caudal: Toward the tail or end of the body, away from the head (Mosby, 1990).

Cephalad: Toward the head (Mosby, 1990).
Chemical incompatibility: Change in the molecular structure or pharmacological properties of a substance that may or may not be visually observed (RCN, 2003).

Compatibility: Capability to be mixed and administered without undergoing undesirable chemical and/or physical changes or loss of therapeutic action (RCN, 2003).

Erythema: Redness of skin along vein track that results from vascular irritation or capillary congestion in response to irritation; may be a precursor to phlebitis (RCN, 2003).

Extension Sets:

  • Are customized IV tubing which adds length to the administration set, or alternatively may be capped and added to PVAD to create a saline lock;
  • May be added to CVAD for line maintenance/access; and
  • Are considered part of the device if added under sterile conditions at time of CVAD insertion.

Extravasation: Inadvertent infiltration of vesicant solution of mediation into surrounding tissue; rated by a standard scale (RCN, 2003).

Hypertonic: Solution of higher osmotic concentration than that of a reference solution or of an isotonic solution; having a concentration greater than the normal tonicity of plasma (RCN, 2003).

Hypotonic: Solution of lower osmotic concentration than that of a reference solution or of an isotonic solution; having a concentration less than the normal tonicity of plasma (RCN, 2003).

Implanted Vascular Access Device or Implanted Port: A catheter surgically placed into a vessel or body cavity and attached to a reservoir located under the skin (RCN, 2003).

Incompatible: Incapable of being mixed or used simultaneously without undergoing chemical or physical changes or producing undesirable effects (RCN, 2003).

Infiltration: Inadvertent administration of a non-vesicant solution or medication into surrounding tissue; rated by a standard scale (RCN, 2003).

Irritant: Agent capable of producing discomfort or pain at the venipuncture site or along the internal lumen of the vein (RCN, 2003).

Isotonic: Having the same osmotic concentration as the solution with which it is compared (i.e., plasma) (RCN, 2003).

Midline catheter: A midline catheter is a device that is inserted via the antecubital veins and advanced into the veins of the upper arm but not extending past the axilla (usually about 20cm in length (RCN, 2003).

Milliosmoles (mOsm): One-thousandth of an osmole; osmotic pressure equal to one-thousandth of the molecular weight of a substance divided by the number of ions that the substance forms in a litre of solution (RCN, 2003).

Occluded: Blocked because of precipitation of infusate, clot formation or anatomic compression (RCN, 2003).

Osmolality: Characteristic of a solution determined by the iconic concentration of the dissolved substances per unit of solvent; measured in milliosmoles per kilogram (RCN, 2003).

Osmolarity: Number of osmotically active particles in a solution (RCN, 2003).

pH: Degree of acidity or alkalinity of a substance (RCN, 2003).
Phlebitis: Inflammation of a vein; may be accompanied by pain, erythema, edema, streak formation and/or palpable cord; rated by a standard scale (RCN, 2003).

Peripherally inserted central catheter (PICC): Soft, flexible, central venous catheter inserted into an extremity and advanced until the tip is positioned in the lower third of the superior vena cava (RCN, 2003).

Personal protective equipment (PPE): Specialized clothing or equipment worn by an employee for protection against an infectious hazard (e.g., gloves, masks, protective eyewear, gowns). General work clothes (e.g., uniforms, pants, shirts or blouses) not intended to function as protection against a hazard and are not considered to be personal protective equipment (CNO, 2004).

Post-infusion phlebitis: Inflammation of the vein occurring after the infusion has been terminated and the catheter removed, usually identified within 48 hours after removal.

Proximal: Closest to the centre of midline of the body or trunk, or nearer to the point of attachment; the opposite of distal (RCN, 2003).

PSI: Pounds per square inch; a measurement of pressure; 1 PSI = 50 mm/Hg (Weinstein, 2001).

Routine Practices: Chosen by Health Canada to emphasize that it is the level of care that should be provided for all clients at all times. It incorporates previous precautions against blood borne pathogens (Universal Precautions) but with the addition of body fluid precautions. The focus is on prevention.

Safety device system/Safety engineered device: Engineered physical attribute of a device that effectively reduces the risk of blood borne pathogen exposure (RCN, 2003).

Standard Precautions: Is the term used by the U.S. Centers for Disease Control and Prevention and is used for what in Canada is known as Routine Practices. The two don’t differ in principle, however; “Standard Precautions” were written for Acute Care Settings and may not be appropriate for community care practice settings.

Tunneled catheter: Vascular access device whose proximal end is tunneled subcutaneously from the insertion site and brought out through the skin at an exit site (see Appendix D) (INS, 2000).

Thrombolytic agent: Pharmacological agent capable of dissolving blood clots (RCN, 2003).

Vesicant: Agent capable of causing injury when it escapes from the intended vascular pathway into surrounding tissue (RCN, 2003).

Universal Precaution: An outdated term used for precautions against blood borne pathogens. Refer to Routine Practices.