There is an increasing awareness of the importance of treating procedure-related pain. Patients undergoing vascular access procedures are often afraid of needles and the discomfort associated with injections. This type of pain and/or fear can be stressful to patients. [1] For prevention of the pain associated with these procedures, the hospital is using Rapydan plasters. Rapydan consists out of two local anesthetics: lidocaine and tetracaïne. Rapydan produces topical anesthesia after an application time of 30 minutes and is used in the Martini Hospital for pain relieve by venipuncture and IV cannulation. The venous blood draining the anaesthetized skin contains a higher blood concentration of the local anesthetics than does venous blood in other parts of the body [2] Although the concentrations of the local anesthetics are low in patients with normal skin, the question is whether the presence of the local anesthetics which Rapydan contains might influence routine measurements in clinical chemistry and hematology.

Inclusion Criteria:

Volunteers 20-60 years who are decision making competent

Exclusion Criteria:

Patients with local anesthetic allergy Patients using antiarrhythmic drugs Patients using other local anesthetics