There are two types of skin preparation: skin cleansing and skin sterilization.
Cleansing of the skin is sufficient for routine injections (subcutaneous, intramuscular, intravenous) and for simple venipuncture but not for venipuncture performed to draw blood for culture or to permit insertion of an indwelling device.
Skin cleansing is generally performed by swabbing the skin for a few seconds with a swab saturated with alcohol (70%) or organic iodine (eg, povidone–iodine or equivalent). To reduce the pain of venipuncture, the disinfectant should be allowed to dry on the skin before the skin is punctured. Note: This procedure merely cleans the skin; it does not sterilize it.
Skin sterilization should be performed before all procedures that involve puncturing or cutting the skin, with the exception of routine venipuncture and simple injections. This procedure eliminates superficial skin bacterial, leaving only a few organisms deep in hair follicles or sweat glands. Skin sterilization may be omitted if the delay involved would jeopardize the patients' life (eg, thoracostomy for tension pneumothorax).
A variety of techniques can be used to achieve skin sterilization:
Scrub the skin vigorously with copious amounts of 70% alcohol for 2 minutes or
Use a sterile 10 × 10 cm2 (4 × 4 inch2) gauze pad, and apply 2% iodine tincture to the area and allow the iodine to dry. Then remove it, using 70% alcohol on a sterile pad, because iodine may cause skin burns or
Apply an organic iodine disinfectant (eg, povidone–iodine or poloxamer–iodine) twice, allowing each application to dry. These particular disinfectants need not be removed before the procedure is started.
The following guidelines should be observed in all cases:
- Sterilize a much larger area of skin than is required for the procedure.
- Apply the disinfectant starting at the site of the procedure and extending outward in concentrically larger circles.
- Use sterile gloves to apply the disinfectant.
It is virtually impossible to achieve sterile technique at the bedside in the emergency department comparable to that obtainable in an operating room; however, following the guidelines outlined below decreases the risk of infection. Good lighting is helpful for maintaining sterile technique and is essential for performing procedures successfully.
Wash hands thoroughly, preferably with antiseptic soap, before performing any procedure.
Have all necessary equipment assembled and opened at the bedside, so that once sterile gloves have been donned, only sterile instruments and equipment will be touched. Alternatively, an assistant can open packaged sterile supplies.
Put on sterile gloves.
Sterilize the skin as described above.
Enlarge the sterile field by surrounding the sterile skin with sterile drapes made of cloth or paper. These may come with a window in them which is used to ...