Wound absorbents

Surgical sutures are sterile, flexible strands used to close wounds or to tie off tubular structures such as blood vessels. Made of natural or synthetic fiber and usually attached to a needle, they are available ia monofilament or multifilament forms. Sutures are classified by the United States Pharmacopeia (USP) (1) as either absorbable or nonabsorbable. The USP also categorizes sutures according to size (diameter) and Hsts certain performance requirements. Sutures are regulated by the Food and Dmg Administration (FDA) as medical devices under the Food, Dmg, and Cosmetics (FDC) Act of 1938, the Medical Device Act of 1976, and the Medical Device Reporting regulation of 1995. 

Sutures are required to hold tissues together until the tissues can heal adequately to support the tensions exerted on the wound duting normal activity. Sutures can be used ia skin, muscle, fat, organs, and vessels. Nonabsorbable sutures are designed to remain ia the body for the life of the patient, and are iadicated where permanent wound support is required. Absorbable sutures are designed to lose strength gradually over time by chemical reactions such as hydrolysis. These sutures are ultimately converted to soluble components that are then metabolized and excreted ia urine or feces, or as carbon dioxide ia expired air. Absorbable sutures are iadicated only where temporary wound support is needed. 

Absorbable sutures are classified by the USP into coUagen and synthetic sutures. Synthetic absorbable sutures are available as braids or monofilaments. Absorbable sutures are only intended for indications where temporary wound support is needed. 

Dextrans are particularly useful and are employed as a plasma substitute. A concentration of about 6% dextran (50,000-100,000 relative molecular weight) has equivalent viscosity and colloid-osmotic properties to blood plasma. Dextran can also be used as non-irritant absorbent wound dressings, an application also suited to alginate gels. 

As with carrageenan, another seaweed extract, the ability to bind to calcium makes alginates useful in dairy products as a thickener. It also makes alginates useful as wound dressings, where they absorb fluids, and stop bleeding, and act as a scaffold. 

FIGURE 8.46 Hyaluronic acid has the consistency of a soft gel. It absorbs water easily and bonds with the proteins in the skin, making it useful in the repair of wounds and joint injuries. 

Paraffin gauze dressing Perforated film absorbent dressing Polyurethane foam Burns, scaids, grafts Postoperative wounds Burns, ulcers, grafts. Any combination of dry heat, gamma-radiation and ethylene oxide... 

Absorbent cotton gauze Absorbent wound dressing Any method... 

The reduction of blood loss during or after surgical procedures where suturing or hgature is either impractical or impossible can often be accomphshed by the use of sterile, absorbable haemostats. These consist of a soft pad of sohd material packed around and over the wound which can be left in situ, being absorbed by body tissues over a period of time, usually up to 6 weeks. The principal mechanism of action of these is the ability to encourage platelet fiacture because of their fibrous or rough surfaces, and to act as a... 

The use of strands of material to tie off blood or other vessels (ligature) and to stitch wounds (suture) is an essential part of surgeiy. Both absorbable and non-absorbable materials are available for this purpose. 

Dextrans are produced commercially for use as plasma substitutes (plasma expanders) which can be administered by intravenous injection to maintain or restore the blood volume. They can be used in applications to ulcers or bum wounds where they form a hydrophilic layer which absorbs fluid exudates. 

Some surgeons advocate direct application to the wound of or irrigation of the wound with either antibiotics or povidone-iodine during colon resection. Solutions containing povidone-iodine should almost never be placed in the peritoneal cavity, because they are likely to be absorbed and subsequently to cause toxic effects. 

Figure 13.9 k soldier wounded at the Battle of Corunna (a battle in the Peninsular War) suffering simultaneous contraction of all muscles after infection with the bacterium, Clostridium tetani. Both agonist and antagonist muscles are active in this condition. The bacterium is found in the earth, especially in places where animal faeces have been present. Bacteria invade the body through a wound, especially in soldiers in battle. The bacterium secretes a toxin that is absorbed into the motor nerves which then become acutely responsive to mild stimuli. It can lead to death unless treated (from Bell 1824). The toxin is now used in cosmetic manipulation to stimulate contraction of muscles in the face to tighten the skin which removes or conceals wrinkles (Botox). 

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