Abstract: A guarded finger scalpel is squeezed between the thumb and forefinger to advance a blade out of an opening. The blade is used to make an incision in the patient's skin, thereby facilitating insertion of a catheter and its line in a patient. Thereafter, the manual pressure is released, and the blade is automatically retracted. This prevents inadvertent or accidental nicks or cuts and hence eliminates or, at least, substantially reduces the exposure to the AIDS virus or other infectious diseases. A lock-off means is employed, subsequent to the surgical procedure, to prevent further blade exposure during clean-up and disposal.