Film dressings provide a simple and effective method of creating a moist wound environment and promoting healing in shallow wounds. They are indicated for the management of minor burns and simple wounds and their flexibility also means that they can be used to cover sutures following surgery. This article examines the main innovations in film dressing technology currently available to clinicians.

INTRODUCTION
Film dressings can be used as primary or secondary dressings and often form part of the construction of other dressings such as hydrocolloids, foams, hydrogel sheets and composite dressings, which are made up of several materials with the film being used as the outer layer. Films are also used as theatre drapes, as a seal in negative pressure wound therapy systems and as a protective cover over intravenous catheter sites to prevent infection. Film dressings have a long history in wound management and are frequently used in day-to-day clinical practice.


BACKGROUND
The first film-like product was manufactured from isinglass (a form of collagen obtained from the dried swim bladders of fish) in the 1880s. These were used as post skin graft dressings and were considered a major advance in wound management at the time [1]. Later, during the Second World War in Italy, Bloom described the use of cellophane in burns patients [2], while in 1948 Bull et al developed a nylon film dressing [3].
 
Schilling et al conducted the first clinical trial of a film dressing in 1950 [4], although the first major trial was the now famous Winter study, which was conducted on animals in 1962 [5]. A 1963 study on humans by Hinman [6], provided further support for the clinical use of film dressings.
 
In 1971, Smith & Nephew launched Opsite™, an incise drape made from a type-1 polyurethane coated with a vinyl ether adhesive. Over the years other companies followed this lead and introduced their own versions [1].

Modern film dressings are manufactured from thin polyurethane (polymer) membranes coated with a layer of acrylic adhesive and are moisture vapour- and oxygen-permeable, although these properties vary from brand to brand. They are impermeable to microorganisms and moisture and their flexibility and transparency allows for the easy assessment of wounds.
 
Importantly, traditional simple film dressings do not permit the absorbtion of exudate.


INDICATIONS FOR USE
Film dressings are indicated for the management of minor burns and simple wounds (eg scalds, abrasions, lacerations and lightly exudating wounds). Their flexibility also means that they can be used to cover sutures following surgery[7,8]. Even after sutures or clips are removed, film dressings can still be applied over an incision site for a few months and are especially good at reducing the skin tension on flexor surfaces.
 
Film dressings can also be used in the following circumstances:

• To protect the skin from shearing forces [9-12]
• As a protective and securing cover for intravenous catheters [13]
• To prevent and treat superficial pressure ulcers [14]
• To provide a semi-occlusive dressing over topical anaesthetic cream to improve absorption into the skin [7,8,15-21]
• To protect donor sites following skin harvesting [22,23]
• Polyurethane films can also be used as a carrier vehicle for antiseptics.